Objective:To observe the chitooligosaccharides(COS) effect on the proliferation inhibition and radiosensitivity of three types of human gastric cancer cell line.Mothods:CCK-8 assay was employed to obtain the inhibitio...Objective:To observe the chitooligosaccharides(COS) effect on the proliferation inhibition and radiosensitivity of three types of human gastric cancer cell line.Mothods:CCK-8 assay was employed to obtain the inhibition ratio of COS on BGC823 cells,MKN45 cells and SGC7901 cells at 48 h after treatment and the proliferation-inhibition curve was drawn with the inhibition ratio of COS on three types of cells.The clonogenic assay was used to detect the cell viability of 0,1,2,4,6 and 8 Gy(6 dose grades) in RAY group and RAY+COS group after X-ray,and the cell survival curve was used to analyze the sensitization enhancement ratio of COS.Flow cytometry was employed to detect cell cycle and apoptosis rate in control group,RAY group and RAY+COS group after 48 h treatment.Results:COS inhibited the proliferation of three types of cells.The inhibition rate was positively correlated with the concentration of COS,and the susceptibility of MKN45 cells,SGC7901 cells and BGC823 cells to COS decreased in turn.The cell viability decreased gradually with the increasing radiation dose in RAY group and RAY+COS group(P<0.01).The cell viabilities of RAY+COS group were lower than those of RAY group at all the dose grades under X-ray exposure(P<0.01),and the sensitization enhancement ratios of COS on BGC823 cells,MKN45 cells and SGC7901 cells were 1.06,1.28 and 1.15 respectively.In controlled trials,apoptosis rate and percentage in the G_2/M phase of three types of cells in RAY+COS group were higher than those in control group and RAY group,and percentage in the S phase and the G_0/G_1 phase in RAY+COS group were lower than those in the other two groups(P<0.01).Conclusions:COS can inhibit the proliferation of three types of human gastric cancer cells and enhance the radiosensitivity by inducing apoptosis and G_2/M phase arrest.展开更多
Objective: To observe the anti-proliferation and radiosensitization effect of chitooligosaccharides(COS) on human lung cancer cell line Hep G2. Methods: CCK-8 assay was employed to obtain the inhibition ratio of COS o...Objective: To observe the anti-proliferation and radiosensitization effect of chitooligosaccharides(COS) on human lung cancer cell line Hep G2. Methods: CCK-8 assay was employed to obtain the inhibition ratio of COS on Hep G2 cells at 24 h after treatment. The clonogenic assay was used to analyze the cell viability of RAY group and RAY+COS group with X-ray of 0, 1, 2, 4, 6 and 8 Gy, and the cell survival curve was used to analyze the sensitization ratio of COS. Flow cytometry was employed to detect cell cycle and apoptosis rate in control group, RAY group and RAY+COS group after 24 h treatment. Results: COS inhibited the proliferation of Hep G2 cells, and the inhibition rate positively correlated with the concentration of COS. The cell viability decreased with increasing exposure dose in RAY group and RAY+COS group. The cell viabilities of RAY+COS group were lower than those of RAY group at the dose of 4, 6 and 8 Gy(P<0.05), and the sensitization ratio of COS was 1.19. There were higher percentage at G2/M phase and apoptosis rate, and lower percentage at S phase in RAY+COS group versus the other two groups(P<0.01). Conclusions: COS can inhibit the proliferation of Hep G2 cells, and enhance the radiosensitization of Hep G2 cells, induce apoptosis and G2/M phase arrest.展开更多
This study examined the role of PI3K/Akt pathway in radiosensitization of DNA damage of cervical carcinoma cells.The 50% inhibition concentration(IC50) of cisplatin and docetaxel in HeLa cells was detected by Mono-nuc...This study examined the role of PI3K/Akt pathway in radiosensitization of DNA damage of cervical carcinoma cells.The 50% inhibition concentration(IC50) of cisplatin and docetaxel in HeLa cells was detected by Mono-nuclear cell direct cytotoxicity assay(MTT) in vitro.HeLa cells were treated by cisplatin/docetaxel of 10 percent of IC20 alone or combined with LY294002 for 24 h,and then radiated by different doses of X-ray.The cell survival ratio was obtained by means of clone formation.One-hit multi-target model was fitted to the cell survival curve to calculate dose quasithreshold(Dq),mean lethal dose(D0),2Gy survival fraction(SF2) and sensitization enhancement ratio(SER).The pAkt and total Akt expression was detected by Western blotting and DNA damage by neutro-comet electrophoresis.The HeLa cells were randomly divided into 7 groups in terms of different treatments:Control;radiation treatment(RT) group;LY294002+RT group;cisplatin+RT group;docetaxel+RT group;LY294002+cisplatin+RT group;LY294002+docetaxel+RT group.The apoptosis ratio of each group was measured by flow cytometry.The results showed that docetaxel and cisplatin significantly enhanced the phosphorylation of Akt in radiation-treated HeLa cells.The Dq,D0 and SF2 in LY294002-contained groups were lower than those in docetaxel or cisplatin+RT group.The SER in the LY294002+docetaxel+RT group was 1.35 times that of the docetaxel+RT group,and that in the LY294002+cisplatin+RT group 1.26 times that of the cisplatin+RT group.The Comet electrophoresis showed that tail distance in the LY294002+cisplatin+RT group or LY294002+docetaxel+RT group was longer than in the cisplatin+RT group or docetaxel+RT group.The apoptosis ratio in the LY294002+cisplatin+RT group or LY294002+docetaxel +RT group was higher than in the cisplatin+RT group or docetaxel+RT group.It was concluded that inhibiting PI3K/Akt pathway can increase the effect of docetaxel and cisplatin on the radiosensitivity of HeLa cells and DNA damage resulted from radiation.展开更多
Objective:To explore the role of cyclophilin A(CyPA)in sensitization of lung adenocarcinoma to radiotherapy using CRISPR/Cas9 technology.Methods:A CyPA knockout human lung adenocarcinoma cell line H1975 was establishe...Objective:To explore the role of cyclophilin A(CyPA)in sensitization of lung adenocarcinoma to radiotherapy using CRISPR/Cas9 technology.Methods:A CyPA knockout human lung adenocarcinoma cell line H1975 was established by CRISPR/Cas9 technology.Groups included a control group(wildtype),CyPA knockout group,traditional Chinese medicine(TCM)extract with Fuzhengzengxiao decoction group,and TCM extract with Fuzhengzengxiao decoction t CyPA knockout group.Each group was exposed to radiation at doses of 0,2,4,6,and 8 Gy.After 24 h,MTT assays were used to determine the survival rate of lung cancer cells and calculate radiosensitivity.The qPCR was used to measure mRNA expression of DDIT3,CDKN1A,and CDC25A associated with DNA damage repair.Results:Without irradiation,Fuzhengzengxiao decoction reduced the survival rate of lung adenocarcinoma cells(P<.0001).After irradiation,TCM extract with Fuzhengzengxiao decoction,CyPA knockout,and TCM extract with Fuzhengzengxiao decoction t CyPA knockout groups had reduced survival rates(P<.0001)and radiosensitivity was increased significantly.Expression of DDIT3,CDKN1A,and CDC25A was upregulated after knockout of CyPA(P<.0001).Expression of DDIT3 and CDC25A was increased after irradiation in wildtype cells treated with TCM extract with Fuzhengzengxiao decoction(DDIT3,P<.0001;CDC25A,P紏.0059).The TCM extract with Fuzhengzengxiao decoction t CyPA knockout group also had increased expression of DDIT3 and CDC25A after irradiation(P<.0001).Conclusion:Fuzhengzengxiao decoction significantly decreases the survival rate of lung cancer cells,and its mechanism may be related to radiosensitization by decreasing expression of CyPA and inducing G1/S cell cycle arrest.展开更多
Nanoparticles(NPs) with high-Z atoms have been widely studied as radiosensitizers for use in cancer therapy. Over the past few years, the application of FePt NPs has attracted extensive research interest. Promising re...Nanoparticles(NPs) with high-Z atoms have been widely studied as radiosensitizers for use in cancer therapy. Over the past few years, the application of FePt NPs has attracted extensive research interest. Promising results have been obtained, yet limited knowledge is available regarding its potential use as a radiosensitizer.The goal of this study is to investigate the radiosensitization capability of FePt nanoparticle clusters(NPCs) under the exposure of kilovoltage photons using Monte Carlo simulation. First, in order to obtain a realistic distribution of NPCs on the microscopic level, Hela cells were incubated with FePt NPs, and the distribution of NPCs was obtained by optical microscope images and X-ray NanoCT experiments. Based on these images, a simplified cellmodel was developed to evaluate the DER of two material types(FePt and FePt_3). For each type, the dependence of DER on the thickness and angular distribution of NPCs on the surface of the cell membrane was studied quantitatively. Our results suggest that DER is strongly dependent on photon energy and the distance from the NPCs to the nucleus. Fe_1 Pt_3 is able to achieve a higher DER relative to Fe_1 Pt_1. For a given X-ray energy, DER demonstrates an initial increase to a maximum value but gradually saturates as the thickness of NPCs increases from 250 up to 2000 nm due to a trapping effect. The impact on DER resulting from the coexistence of the NPCs on the cell membrane and the nuclear membrane was also investigated.展开更多
Objective We aimed to observe the radiosensitization effect of mir-30a-5p in a nude mouse model with subcutaneous lung-cancer xenograft and to explore the underlying mechanism.Methods A549 cell lines with either stabl...Objective We aimed to observe the radiosensitization effect of mir-30a-5p in a nude mouse model with subcutaneous lung-cancer xenograft and to explore the underlying mechanism.Methods A549 cell lines with either stable upregulation or downregulation of mir-30a-5p,and their negative control,were transfected with lentivirus vectors.These cell lines were used to establish a nude mouse model with subcutaneous lung-cancer xenograft.Each group was randomly divided into irradiated and non-irradiated groups.The radiosensitization effect of mir-30a-5p in vivo was studied by observing xenograft growth trends and tumor weight.The mechanisms involved in this radiosensitization were investigated by detecting expressed radiosensitization-related proteins,using immunohistochemistry and Western blotting.Results The expression level of mir-30a-5p in the lenti-mir-30a-5p group was higher than that in the negative control(lenti-GFP)group and lower in the lenti-inhibitor group(P<0.05).Subcutaneous lung-cancer xenografts in the irradiation group and lenti-mir-30a-5p increased in size slowly;tumors were lighter and tumor inhibition rates were higher than those in the non-irradiation and lenti-GFP groups.In contrast,the opposite of these effects was observed in the lenti-inhibitor group.Immunohistochemistry and Western blotting indicated that ATM protein expression level was lower in the lenti-mir-30a-5p group,with or without irradiation,compared to that in the lenti-GFP group.ATM protein levels were higher in the lenti-inhibitor groups.The phosphorylation level of ATM at residue 1981 was low in the groups without irradiation and increased significantly after irradiation(P<0.05).Moreover,the phosphorylation level was lower in the lenti-mir-30a-5p group and higher in the lenti-inhibitor group than that in the lenti-GFP group after irradiation(P<0.05).Conclusion Mir-30a-5p enhanced the radiosensitivity of nude mice with subcutaneous lung-cancer xenografts by inhibiting ATM phosphorylation.展开更多
Telomerase inhibitor MST-312 is a new compound derived from epigallocatechin gallate (EGCG)[1]. Our resultsdemonstrated that 4 M MST-312 not only showed lower cytotoxicity, but also inhibited telomerase activity inHe...Telomerase inhibitor MST-312 is a new compound derived from epigallocatechin gallate (EGCG)[1]. Our resultsdemonstrated that 4 M MST-312 not only showed lower cytotoxicity, but also inhibited telomerase activity inHepG2 cells. Therefore, in our experiments, 4 M MST-312 was chosen to study radiosensitization and relatedmechanisms. -H2AX foci are considered as an indicator of DNA damages[2]. The immunofluorescence stainingresults showed the number of -H2AX foci in the pretreatment with MST-312 followed by 2 Gy X-ray irradiationgroup. However, as shown in Fig. 1, the formation of Rad51 foci in the combined treatment group was blockedoutside the nuclear of HepG2 cells, when compared with the irradiation alone group. JC-1 staining showed thatMST-312 pretreatment, followed by X-ray irradiation, caused increase of the green/red fluorescence intensity ratio(ΔΨm) compared with X-ray irradiation alone. Meanwhile, MST-312 pretreatment followed by X-ray irradiationelevated expression of p53 protein and decreased expression of caspase-3 as well as fraction of Bcl-2 / Bax.展开更多
Objective:The aim of the present study was to investigate the mechanisms responsible for the radiation-sensitizing effect of antennapedia proteins,ANTP-SMACN7,on lung cancer cells treated with accelerated carbon and F...Objective:The aim of the present study was to investigate the mechanisms responsible for the radiation-sensitizing effect of antennapedia proteins,ANTP-SMACN7,on lung cancer cells treated with accelerated carbon and Fe particle irradiation.Methods:The ANTP-SMACN7 fusion peptide was synthesized and linked to fluorescein isothiocyanate to determine its ability to penetrate cells.A549 and NCI-H460 cells,human non-small cell lung cancer(NSCLC)cell lines,were irradiated with X-ray or high linear energy transfer(LET)irradiation with or without ANTP-SMACN7 treatment.Cellular survival,apoptosis,and protein expression were studied by colony formation assays,flow cytometry,and western blot analyses,respectively.Results:ANTP-SMACN7 fusion proteins entered the cells and promoted A549 and NCI-H460 cell high LET irradiation radiosensitization.High LET irradiation was more efficient for clonogenic cell killing and the induction of apoptosis(P<0.05).Treatment with ANTP-SMACN7 significantly reduced the A549 and NCI-H460 cell clone-forming percentages and increased apoptosis through inhibition of the X-linked inhibitor of apoptosis protein and the activation of caspase-3 and caspase-9.Conclusions:Regarding pharmaceutical radiosensitization,these findings provided a way to improve high-LET clinical radiotherapy for NSCLC patients.展开更多
Radiotherapy is commonly used to treat advanced pancreatic cancers and can improve survival by2 months in combination with gemcitabine.However,prognosis and survival improvement remain unsatisfactory,and effective the...Radiotherapy is commonly used to treat advanced pancreatic cancers and can improve survival by2 months in combination with gemcitabine.However,prognosis and survival improvement remain unsatisfactory,and effective therapies are urgently needed.Piperlongumine has been demonstrated to have therapeutic potentials against various cancers.In this study,we synthesized a series of piperlongumine derivatives and provided evidence that piperlongumine derivatives could be used as effective radiosensitizers in pancreatic cancer.Two compounds enhanced the radiosensitivity of Panc-1 and SW1990 cells.In a pancreatic bi-flank xenograft tumor model,they significantly inhibited tumor growth.Piperlongumine derivatives could induce reactive oxygen species(ROS)expression and regulate the Keapl-Nrf2 protective pathway with enhancement of radiation-induced DNA damage,G2/M-phase cell cycle arrest,and apoptosis.Collectively,our data offer a proof of concept for the use of piperlongumine derivatives as a novel class of radiosensitizers for the treatment of pancreatic cancer.展开更多
Riboflavin, suggested to be a radiosensitizer, was studied in murine thymocytes and human hepatoma L02 cell line in vitro with MTT method and fluorescence microscopy. When the murine thymocytes treated with 5-400 μmo...Riboflavin, suggested to be a radiosensitizer, was studied in murine thymocytes and human hepatoma L02 cell line in vitro with MTT method and fluorescence microscopy. When the murine thymocytes treated with 5-400 μmol/L riboflavin were irradiated by 5 Gy 60Co γ ionizing radiation, the low concentration groups, i.e. treated with 5-50 μmol/L riboflavin, showed a different surviving fractions-time relating correlation compared with the high concentration groups, i.e. treated with 100-400 μmol/L riboflavin. The former had a high survival level at the end of irradiation, but which, after 4-h incubation, decreased rapidly to a low level. On the contrary, the high concentration groups showed a low survival level at the end of irradiation, and a poor correlation was found between the surviving fraction and the incubation time, after 4 h a little difference was observed. The results of fluorescence microscopy indicated that under low concentration conditions, the riboflavin localized mainly in nucleus (both perinuclear area and inside of nuclear membrane), while under high concentration conditions, intensive riboflavin also localized around cytoplasmic membranes. Thus we can conclude: the riboflavin had radiosensitivity effect on DNA under low concentration conditions, and enhanced the damage to cytoplasmic membrane under high concentration conditions. Also the most effective concentration of riboflavin can be evaluated to be approximate 100 μmol/L.展开更多
Primary liver cancer is a significant health problem worldwide.Hepatocellular carcinoma(HCC)is the main pathological type of primary liver cancer,accounting for 75%-85%of cases.In recent years,radiotherapy has become ...Primary liver cancer is a significant health problem worldwide.Hepatocellular carcinoma(HCC)is the main pathological type of primary liver cancer,accounting for 75%-85%of cases.In recent years,radiotherapy has become an emerging treatment for HCC and is effective for various stages of HCC.However,radiosensitivity of liver cancer cells has a significant effect on the efficacy of radiotherapy and is regulated by various factors.How to increase radiosensitivity and improve the therapeutic effects of radiotherapy require further exploration.This review summarizes the recent research progress on the mechanisms affecting sensitivity to radiotherapy,including epigenetics,transportation and metabolism,regulated cell death pathways,the microenvironment,and redox status,as well as the effect of nanoparticles on the radiosensitivity of liver cancer.It is expected to provide more effective strategies and methods for clinical treatment of liver cancer by radiotherapy.展开更多
AIM:To investigate whether the inhibition of autophagy by chloroquine(CQ)sensitizes rectal tumors to radiation therapy(RT)or concurrent chemoradiation(chemoRT).METHODS:In vitro,HCT-116 and HT-29 colorectal cancer(CRC)...AIM:To investigate whether the inhibition of autophagy by chloroquine(CQ)sensitizes rectal tumors to radiation therapy(RT)or concurrent chemoradiation(chemoRT).METHODS:In vitro,HCT-116 and HT-29 colorectal cancer(CRC)cell lines were treated as following:(1)PBS;(2)CQ;(3)5-fluorouracil(5-FU);(4)RT;(5)CQ and RT;(6)5-FU and RT;(7)CQ and 5-FU;and(8)5-FU and CQ and RT.Each group was then exposed to various doses of radiation(0-8 Gy)depending on the experiment.Cell viability and proliferative capacity were measured by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and clonogenic assays.Clonogenic survivalcurves were constructed and compared across treatment groups.Autophagy status was determined by assessing the LC3-Ⅱto LC3-Ⅰratio on western blot analysis,autophagosome formation on electron microscopy and identification of a perinuclear punctate pattern with GFPlabeled LC3 on fluorescence microscopy.Cell cycle arrest and cell death were evaluated by FACS and AnnexinⅤanalysis.All experiments were performed in triplicate and statistical analysis was performed by the student’s t test to compare means between treatment groups.RESULTS:RT(2-8 Gy)induced autophagy in HCT-116and HT-29 CRC cell lines at 4 and 6 h post-radiation,respectively,as measured by increasing LC3-Ⅱto LC3-Ⅰratio on western blot.Additionally,electron microscopy demonstrated autophagy induction in HT-29 cells24 h following irradiation at a dose of 8 Gy.Drug treatment with 5-FU(25μmol/L)induced autophagy and the combination of 5-FU and RT demonstrated synergism in autophagy induction.CQ(10μmol/L)alone and in combination with RT effectively inhibited autophagy and sensitized both HCT-116 and HT-29 cells to treatment with radiation(8 Gy;P<0.001 and 0.00001,respectively).Significant decrease in clonogenic survival was seen only in the HT-29 cell line,when CQ was combined with RT at doses of 2 and 8 Gy(P<0.5 and P=0.05,respectively).There were no differences in cell cycle progression or Annexin V staining upon CQ addition to RT.CONCLUSION:Autophagy inhibition by CQ increases CRC cell sensitivity to concurrent treatment with 5-FU and RT in vitro,suggesting that addition of CQ to chemoRT improves CRC treatment response.展开更多
Objective:To explore the influence of silencing Bcl-2 expression by small interfering RNA（siRNA） on Bcl-2 protein expression,cell apoptosis rale and radiosensilivity of gastric cancer BCC823 cells.Methods:siRNA segm...Objective:To explore the influence of silencing Bcl-2 expression by small interfering RNA（siRNA） on Bcl-2 protein expression,cell apoptosis rale and radiosensilivity of gastric cancer BCC823 cells.Methods:siRNA segment for Bcl-2 gene was designed and synthesized,then was induced into gastric cancer BGC 823 cells by liposome transfection.Bcl-2 protein expression was detected by Western Blotting.After X radiation,flow cytometry and clone forming assay were used to determine the effects of RNA interference on BGC823 cell apoptosis rate and radiosensitivity. Result:After the transfection of Bcl-2 siRNA,the positive expression rate of Bcl-2 protein in BGC823 cells was（35.45±2.35）%.Compared with the control group and negative siRNA transfection group,the rate was significantly decreased（P【0.01）.The apoptosis rate of BGC823-RNAi cell was（10.81±0.91）%,which was significantly higher than the control group and negative siRNA transfection group（P【0.01）.After 48h X radiation,the apoptosis rate of BGC823-RNAi was（28.91±1.40）%,which was significantly higher than the control group and the group without radiation （P【0.01）.During clone forming assay D<sub>0</sub>,D<sub>4</sub> and SF<sub>2</sub> values in Bcl-2 siRNA1 transfection group were all lower than those in the control group.The radiosensitivity ratio was 1.28（the ratio of D<sub>0</sub>） and 1.60（the ratio of D<sub>4</sub>）.Conclusions:Specific siRNA of Bcl-2 gene can effectively inhibit the expression of Bcl-2 gene,enhance the radiosensitivity and apoptosis of gastric cancer BGC823 cells,having good clinical application perspective.展开更多
Shengmai Yin(SMY)is a Chinese herbal decoction that effectively alleviates the side effects of radiotherapy in various cancers and helps achieve radiotherapy’s clinical efficacy.In this study,we explored the interact...Shengmai Yin(SMY)is a Chinese herbal decoction that effectively alleviates the side effects of radiotherapy in various cancers and helps achieve radiotherapy’s clinical efficacy.In this study,we explored the interaction mechanism among SMY,DNA methylation,and nasopharyngeal carcinoma(NPC).We identified differences in DNA methylation levels in NPC CNE-2 cells and its radioresistant cells(CNE-2R)using the methylated DNA immunoprecipitation array and found that CNE-2R cells showed genomewide changes in methylation status towards a state of hypomethylation.SMY may restore its original DNA methylation status,and thus,enhance radiosensitivity.Furthermore,we confirmed that the differential gene Tenascin-C(TNC)was overexpressed in CNE-2R cells and that SMY downregulated TNC expression.This downregulation of TNC inhibited NPC cell radiation resistance,migration,and invasion.Furthermore,we found that TNC was hypomethylated in CNE-2R cells and partially restored to a hypermethylated state after SMY intervention.DNA methyltransferases 3 a may be the key protein in DNA methylation of TNC.展开更多
Curcumin is widely reported to have remarkable medicinal- and antineoplastic- properties. This review details curcumin's relationship with radiotherapy(RT), principally as a radiosensitizer for various malignancie...Curcumin is widely reported to have remarkable medicinal- and antineoplastic- properties. This review details curcumin's relationship with radiotherapy(RT), principally as a radiosensitizer for various malignancies and a radioprotector for normal tissues. First, examples of radiosensitization are provided for various cancers:Pediatric, lymphoma, sarcoma, prostate, gynecologic, pancreas, liver, colorectal, breast, lung, head/neck, and glioma. It is not the purpose of this article to comprehensively review all radiosensitization data; however, high-quality studies are discussed in relationship to currently-controversial RT questions for many cancers, and thus the importance of developing a natural radiosensitizer. Attention is then shifted to radioprotection, for which supporting research is discussed for the following RT toxicities: Dermatitis, pneumonitis, cataractogenesis, neurocognition, myelosuppression, secondary malignancies, and mucositis/enteritis. Though there is fewer data for radioprotection, the overall quality of clinical evidence is higher, and small clinical trials implicating the efficacy of curcumin for RT toxicities(vs placebo/current therapies) are also detailed. Though the overall level of evidence for curcumin as a radiosensitizer and radioprotector is low, it must be recognized that risks of adverse effects are exceedingly low, and clinicians may need to judge the yet-unproven rewards with low toxicity risks.展开更多
Objective:Cancer cell radioresistance is a stumbling block in radiation therapy.The activity in the nuclear factor kappa B(NFκB)pathway correlates with anti-apoptotic mechanisms and increased radioresistance.The IKK ...Objective:Cancer cell radioresistance is a stumbling block in radiation therapy.The activity in the nuclear factor kappa B(NFκB)pathway correlates with anti-apoptotic mechanisms and increased radioresistance.The IKK complex plays a major role in NFκB activation upon numerous signals.In this study,we examined the interaction between ionizing radiation(IR)and different members of the IKK-NFκB pathway,as well as upstream activators,RAF1,ERK,and AKT1.Methods:The effect of 4 Gy of IR on the expression of the RAF1-ERK-IKK-NFκB pathway was examined in A549 and H1299 lung cancer cell lines using Western blot analysis and confocal microscopy.We examined changes in radiation sensitivity using gene silencing or pharmacological inhibitors of ERK and IKKβ.Results:IKKα,IKKγ,and IκBαincreased upon exposure to IR,thereby affecting nuclear levels of NFκB(phospho-p65).ERK inhibition or si RNA-mediated down-regulation of RAF1 suppressed the post-irradiation survival of the examined lung cancer cell lines.A similar effect was detected on survival upon silencing IKKα/IKKγor inhibiting IKKβ.Conclusions:Exposure of lung cancer cells to IR results in NFκB activation via IKK.The genetic or pharmacological blockage of the RAF1-ERK-IKK-NFκB pathway sensitizes cells to therapeutic doses of radiation.Therefore,the IKK pathway is a promising target for therapeutic intervention in combination with radiotherapy.展开更多
Background:Ultrasound-triggered microbubble destruction(UTMD) is a widely used noninvasive technology in both military and civilian medicine,which could enhance radiosensitivity of various tumors.However,little inform...Background:Ultrasound-triggered microbubble destruction(UTMD) is a widely used noninvasive technology in both military and civilian medicine,which could enhance radiosensitivity of various tumors.However,little information is available regarding the effects of UTMD on radiotherapy for glioblastoma or the underlying mechanism.This study aimed to delineate the effect of UTMD on the radiosensitivity of glioblastoma and the potential involvement of autophagy.Methods:GL261,U251 cells and orthotopic glioblastoma-bearing mice were treated with ionizing radiation(IR) or IR plus UTMD.Autophagy was observed by confocal microscopy and transmission electron microscopy.Western blotting and immunofluorescence analysis were used to detect progesterone receptor membrane component 1(PGRMC1),light chain 3 beta 2(LC3B2) and sequestosome 1(SQSTM1/p62) levels.Lentiviral vectors or siRNAs transfection,and fluorescent probes staining were used to explore the underlying mechanism.Results:UTMD enhanced the radiosensitivity of glioblastoma in vitro and in vivo(P<0.01).UTMD inhibited autophagic flux by disrupting autophagosome-lysosome fusion without impairing lysosomal function or autophagosome synthesis in IR-treated glioblastoma cells.Suppression of autophagy by 3-methyladenine,bafilomycin A1 or ATG5 siRNA had no significant effect on UTMD-induced radiosensitization in glioblastoma cells(P<0.05).Similar results were found when autophagy was induced by rapamycin or ATG5 overexpression(P>0.05).Furthermore,UTMD inhibited PGRMC1expression and binding with LC3B2 in IR-exposed glioblastoma cells(P<0.01).PGRMC1 inhibitor AG-205 or PGRMC1siRNA pretreatment enhanced UTMD-induced LC3B2 and p62 accumulation in IR-exposed glioblastoma cells,thereby promoting UTMD-mediated radiosensitization(P<0.05).Moreover,PGRMC1 overexpression abolished UTMD-caused blockade of autophagic degradation,subsequently inhibiting UTMD-induced radiosensitization of glioblastoma cells.Finally,compared with IR plus UTMD group,PGRMC1 overexpression significantly increased tumor size [(3.8±1.1) mm^(2)vs.(8.0±1.9) mm^(2),P<0.05] and decreased survival time [(67.2±2.6) d vs.(40.0±1.2) d,P=0.0026] in glioblastoma-bearing mice.Conclusions:UTMD enhanced the radiosensitivity of glioblastoma partially by disrupting PGRMC1-mediated autophagy.展开更多
Objective:We aimed to investigate the radiosensitizing efficacy of the poly-ADP-ribose polymerase(PARP)inhibitor,olaparib,and the Bloom syndrome protein(BLM)helicase inhibitor,ML216,in non-small cell lung cancer(NSCLC...Objective:We aimed to investigate the radiosensitizing efficacy of the poly-ADP-ribose polymerase(PARP)inhibitor,olaparib,and the Bloom syndrome protein(BLM)helicase inhibitor,ML216,in non-small cell lung cancer(NSCLC)cells.Methods:Radiosensitization of NSCLC cells was assessed by colony formation and tumor growth assays.Mechanistically,the effects of ML216,olaparib,and radiation on cell and tumor proliferation,DNA damage,cell cycle,apoptosis,homologous recombination(HR)repair,and non-homologous end joining(NHEJ)repair activity were determined.Results:Both olaparib and ML216 enhanced the radiosensitivities of olaparib-sensitive H460 and H1299 cells,which was seen as decreased surviving fractions and Rad51 foci,increased total DNA damage,andγH2AX and 53BP1 foci(P<0.05).The expressions of HR repair proteins were remarkably decreased in olaparib-treated H460 and H1299 cells after irradiation(P<0.05),while olaparib combined with ML216 exerted a synergistic radiosensitization effect on olaparib-resistant A549 cells.In addition to increases of double strand break(DSB)damage and decreases of Rad51 foci,olaparib combined with ML216 also increased pDNA-PKcs(S2056)foci,abrogated G2 cell cycle arrest,and induced apoptosis in A549 lung cancer after irradiation in vitro and in vivo(P<0.05).Moreover,Western blot showed that olaparib combined with ML216 and irradiation inhibited HR repair,promoted NHEJ repair,and inactivated cell cycle checkpoint signals both in vitro and in vivo(P<0.05).Conclusions:Taken together,these results showed the efficacy of PARP and BLM helicase inhibitors for radiosensitizing NSCLC cells,and supported the model that BLM inhibition sensitizes cells to PARP inhibitor-mediated radiosensitization,as well as providing the basis for the potential clinical development of this combination for tumors intrinsically resistant to PARP inhibitors and radiotherapy.展开更多
基金supported by Youth Science Fund Project(No.81400612)
文摘Objective:To observe the chitooligosaccharides(COS) effect on the proliferation inhibition and radiosensitivity of three types of human gastric cancer cell line.Mothods:CCK-8 assay was employed to obtain the inhibition ratio of COS on BGC823 cells,MKN45 cells and SGC7901 cells at 48 h after treatment and the proliferation-inhibition curve was drawn with the inhibition ratio of COS on three types of cells.The clonogenic assay was used to detect the cell viability of 0,1,2,4,6 and 8 Gy(6 dose grades) in RAY group and RAY+COS group after X-ray,and the cell survival curve was used to analyze the sensitization enhancement ratio of COS.Flow cytometry was employed to detect cell cycle and apoptosis rate in control group,RAY group and RAY+COS group after 48 h treatment.Results:COS inhibited the proliferation of three types of cells.The inhibition rate was positively correlated with the concentration of COS,and the susceptibility of MKN45 cells,SGC7901 cells and BGC823 cells to COS decreased in turn.The cell viability decreased gradually with the increasing radiation dose in RAY group and RAY+COS group(P<0.01).The cell viabilities of RAY+COS group were lower than those of RAY group at all the dose grades under X-ray exposure(P<0.01),and the sensitization enhancement ratios of COS on BGC823 cells,MKN45 cells and SGC7901 cells were 1.06,1.28 and 1.15 respectively.In controlled trials,apoptosis rate and percentage in the G_2/M phase of three types of cells in RAY+COS group were higher than those in control group and RAY group,and percentage in the S phase and the G_0/G_1 phase in RAY+COS group were lower than those in the other two groups(P<0.01).Conclusions:COS can inhibit the proliferation of three types of human gastric cancer cells and enhance the radiosensitivity by inducing apoptosis and G_2/M phase arrest.
文摘Objective: To observe the anti-proliferation and radiosensitization effect of chitooligosaccharides(COS) on human lung cancer cell line Hep G2. Methods: CCK-8 assay was employed to obtain the inhibition ratio of COS on Hep G2 cells at 24 h after treatment. The clonogenic assay was used to analyze the cell viability of RAY group and RAY+COS group with X-ray of 0, 1, 2, 4, 6 and 8 Gy, and the cell survival curve was used to analyze the sensitization ratio of COS. Flow cytometry was employed to detect cell cycle and apoptosis rate in control group, RAY group and RAY+COS group after 24 h treatment. Results: COS inhibited the proliferation of Hep G2 cells, and the inhibition rate positively correlated with the concentration of COS. The cell viability decreased with increasing exposure dose in RAY group and RAY+COS group. The cell viabilities of RAY+COS group were lower than those of RAY group at the dose of 4, 6 and 8 Gy(P<0.05), and the sensitization ratio of COS was 1.19. There were higher percentage at G2/M phase and apoptosis rate, and lower percentage at S phase in RAY+COS group versus the other two groups(P<0.01). Conclusions: COS can inhibit the proliferation of Hep G2 cells, and enhance the radiosensitization of Hep G2 cells, induce apoptosis and G2/M phase arrest.
基金supported by grants from the Hubei Province Natural Sciences Foundation (No.2008cdb133)Science Foundation for The Youth Scholars of Ministry of Education of China (No.200804871034)
文摘This study examined the role of PI3K/Akt pathway in radiosensitization of DNA damage of cervical carcinoma cells.The 50% inhibition concentration(IC50) of cisplatin and docetaxel in HeLa cells was detected by Mono-nuclear cell direct cytotoxicity assay(MTT) in vitro.HeLa cells were treated by cisplatin/docetaxel of 10 percent of IC20 alone or combined with LY294002 for 24 h,and then radiated by different doses of X-ray.The cell survival ratio was obtained by means of clone formation.One-hit multi-target model was fitted to the cell survival curve to calculate dose quasithreshold(Dq),mean lethal dose(D0),2Gy survival fraction(SF2) and sensitization enhancement ratio(SER).The pAkt and total Akt expression was detected by Western blotting and DNA damage by neutro-comet electrophoresis.The HeLa cells were randomly divided into 7 groups in terms of different treatments:Control;radiation treatment(RT) group;LY294002+RT group;cisplatin+RT group;docetaxel+RT group;LY294002+cisplatin+RT group;LY294002+docetaxel+RT group.The apoptosis ratio of each group was measured by flow cytometry.The results showed that docetaxel and cisplatin significantly enhanced the phosphorylation of Akt in radiation-treated HeLa cells.The Dq,D0 and SF2 in LY294002-contained groups were lower than those in docetaxel or cisplatin+RT group.The SER in the LY294002+docetaxel+RT group was 1.35 times that of the docetaxel+RT group,and that in the LY294002+cisplatin+RT group 1.26 times that of the cisplatin+RT group.The Comet electrophoresis showed that tail distance in the LY294002+cisplatin+RT group or LY294002+docetaxel+RT group was longer than in the cisplatin+RT group or docetaxel+RT group.The apoptosis ratio in the LY294002+cisplatin+RT group or LY294002+docetaxel +RT group was higher than in the cisplatin+RT group or docetaxel+RT group.It was concluded that inhibiting PI3K/Akt pathway can increase the effect of docetaxel and cisplatin on the radiosensitivity of HeLa cells and DNA damage resulted from radiation.
基金This work was supported by NSFC project(No.81573736).
文摘Objective:To explore the role of cyclophilin A(CyPA)in sensitization of lung adenocarcinoma to radiotherapy using CRISPR/Cas9 technology.Methods:A CyPA knockout human lung adenocarcinoma cell line H1975 was established by CRISPR/Cas9 technology.Groups included a control group(wildtype),CyPA knockout group,traditional Chinese medicine(TCM)extract with Fuzhengzengxiao decoction group,and TCM extract with Fuzhengzengxiao decoction t CyPA knockout group.Each group was exposed to radiation at doses of 0,2,4,6,and 8 Gy.After 24 h,MTT assays were used to determine the survival rate of lung cancer cells and calculate radiosensitivity.The qPCR was used to measure mRNA expression of DDIT3,CDKN1A,and CDC25A associated with DNA damage repair.Results:Without irradiation,Fuzhengzengxiao decoction reduced the survival rate of lung adenocarcinoma cells(P<.0001).After irradiation,TCM extract with Fuzhengzengxiao decoction,CyPA knockout,and TCM extract with Fuzhengzengxiao decoction t CyPA knockout groups had reduced survival rates(P<.0001)and radiosensitivity was increased significantly.Expression of DDIT3,CDKN1A,and CDC25A was upregulated after knockout of CyPA(P<.0001).Expression of DDIT3 and CDC25A was increased after irradiation in wildtype cells treated with TCM extract with Fuzhengzengxiao decoction(DDIT3,P<.0001;CDC25A,P紏.0059).The TCM extract with Fuzhengzengxiao decoction t CyPA knockout group also had increased expression of DDIT3 and CDC25A after irradiation(P<.0001).Conclusion:Fuzhengzengxiao decoction significantly decreases the survival rate of lung cancer cells,and its mechanism may be related to radiosensitization by decreasing expression of CyPA and inducing G1/S cell cycle arrest.
基金supported by the Natural Science Foundation of China(Nos.10875092 and 31271511)the Natural Science Foundation of Hubei Province of China(No.2012KB04449)
文摘Nanoparticles(NPs) with high-Z atoms have been widely studied as radiosensitizers for use in cancer therapy. Over the past few years, the application of FePt NPs has attracted extensive research interest. Promising results have been obtained, yet limited knowledge is available regarding its potential use as a radiosensitizer.The goal of this study is to investigate the radiosensitization capability of FePt nanoparticle clusters(NPCs) under the exposure of kilovoltage photons using Monte Carlo simulation. First, in order to obtain a realistic distribution of NPCs on the microscopic level, Hela cells were incubated with FePt NPs, and the distribution of NPCs was obtained by optical microscope images and X-ray NanoCT experiments. Based on these images, a simplified cellmodel was developed to evaluate the DER of two material types(FePt and FePt_3). For each type, the dependence of DER on the thickness and angular distribution of NPCs on the surface of the cell membrane was studied quantitatively. Our results suggest that DER is strongly dependent on photon energy and the distance from the NPCs to the nucleus. Fe_1 Pt_3 is able to achieve a higher DER relative to Fe_1 Pt_1. For a given X-ray energy, DER demonstrates an initial increase to a maximum value but gradually saturates as the thickness of NPCs increases from 250 up to 2000 nm due to a trapping effect. The impact on DER resulting from the coexistence of the NPCs on the cell membrane and the nuclear membrane was also investigated.
基金supported by the National Science Fund Project (No. 81872471)the National Natural Science Foundation of China and the Science Foundation of the Second Affiliated Hospital of Xi’an Jiaotong University (No. YJ(QN)202025)
文摘Objective We aimed to observe the radiosensitization effect of mir-30a-5p in a nude mouse model with subcutaneous lung-cancer xenograft and to explore the underlying mechanism.Methods A549 cell lines with either stable upregulation or downregulation of mir-30a-5p,and their negative control,were transfected with lentivirus vectors.These cell lines were used to establish a nude mouse model with subcutaneous lung-cancer xenograft.Each group was randomly divided into irradiated and non-irradiated groups.The radiosensitization effect of mir-30a-5p in vivo was studied by observing xenograft growth trends and tumor weight.The mechanisms involved in this radiosensitization were investigated by detecting expressed radiosensitization-related proteins,using immunohistochemistry and Western blotting.Results The expression level of mir-30a-5p in the lenti-mir-30a-5p group was higher than that in the negative control(lenti-GFP)group and lower in the lenti-inhibitor group(P<0.05).Subcutaneous lung-cancer xenografts in the irradiation group and lenti-mir-30a-5p increased in size slowly;tumors were lighter and tumor inhibition rates were higher than those in the non-irradiation and lenti-GFP groups.In contrast,the opposite of these effects was observed in the lenti-inhibitor group.Immunohistochemistry and Western blotting indicated that ATM protein expression level was lower in the lenti-mir-30a-5p group,with or without irradiation,compared to that in the lenti-GFP group.ATM protein levels were higher in the lenti-inhibitor groups.The phosphorylation level of ATM at residue 1981 was low in the groups without irradiation and increased significantly after irradiation(P<0.05).Moreover,the phosphorylation level was lower in the lenti-mir-30a-5p group and higher in the lenti-inhibitor group than that in the lenti-GFP group after irradiation(P<0.05).Conclusion Mir-30a-5p enhanced the radiosensitivity of nude mice with subcutaneous lung-cancer xenografts by inhibiting ATM phosphorylation.
基金Key Program of National Natural Science Foundation of China (U1432248), National Natural Science Foundationof China (11175222, 11205219), Western Talent Program of Chinese Academy of Sciences (Y460040XB0, Y160180XB0).
文摘Telomerase inhibitor MST-312 is a new compound derived from epigallocatechin gallate (EGCG)[1]. Our resultsdemonstrated that 4 M MST-312 not only showed lower cytotoxicity, but also inhibited telomerase activity inHepG2 cells. Therefore, in our experiments, 4 M MST-312 was chosen to study radiosensitization and relatedmechanisms. -H2AX foci are considered as an indicator of DNA damages[2]. The immunofluorescence stainingresults showed the number of -H2AX foci in the pretreatment with MST-312 followed by 2 Gy X-ray irradiationgroup. However, as shown in Fig. 1, the formation of Rad51 foci in the combined treatment group was blockedoutside the nuclear of HepG2 cells, when compared with the irradiation alone group. JC-1 staining showed thatMST-312 pretreatment, followed by X-ray irradiation, caused increase of the green/red fluorescence intensity ratio(ΔΨm) compared with X-ray irradiation alone. Meanwhile, MST-312 pretreatment followed by X-ray irradiationelevated expression of p53 protein and decreased expression of caspase-3 as well as fraction of Bcl-2 / Bax.
基金supported by grants from the National Key R&D Program of China(Grant Nos.2018YFE0205100 and 2018YFE0205101)the National Natural Science Foundation of China(Grant Nos.11605260 and 31670859)+4 种基金the Key Research and Development Projects of Shanxi Province(Grant No.201903D321115)the Science and Technology Talent Project in Lanzhou(Grant No.2018-RC-66)the Science and Technology Project of Chengguan District of Lanzhou(Grant No.2020RCCX0038)the CAMS Innovation Fund for Medical Science(Grant No.2017-I2M-1-016)the Ministry of Education,Culture,Sports,and Science Technology Grantin-Aid for Scientific Research on Innovative Areas with Heavy Ions at NIRS-HIMAC,Japan[Grant Nos.JP15K21745,15H05944,and 15H05935(Living in Space),and Research Project Grant(14J313)].
文摘Objective:The aim of the present study was to investigate the mechanisms responsible for the radiation-sensitizing effect of antennapedia proteins,ANTP-SMACN7,on lung cancer cells treated with accelerated carbon and Fe particle irradiation.Methods:The ANTP-SMACN7 fusion peptide was synthesized and linked to fluorescein isothiocyanate to determine its ability to penetrate cells.A549 and NCI-H460 cells,human non-small cell lung cancer(NSCLC)cell lines,were irradiated with X-ray or high linear energy transfer(LET)irradiation with or without ANTP-SMACN7 treatment.Cellular survival,apoptosis,and protein expression were studied by colony formation assays,flow cytometry,and western blot analyses,respectively.Results:ANTP-SMACN7 fusion proteins entered the cells and promoted A549 and NCI-H460 cell high LET irradiation radiosensitization.High LET irradiation was more efficient for clonogenic cell killing and the induction of apoptosis(P<0.05).Treatment with ANTP-SMACN7 significantly reduced the A549 and NCI-H460 cell clone-forming percentages and increased apoptosis through inhibition of the X-linked inhibitor of apoptosis protein and the activation of caspase-3 and caspase-9.Conclusions:Regarding pharmaceutical radiosensitization,these findings provided a way to improve high-LET clinical radiotherapy for NSCLC patients.
基金supported by grants from the Shanghai Municipal Commission of Health and Family Planning(No.2017YQ052)the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(No.2017QNRC061)+3 种基金the National Natural Science Foundation of China(Nos.81673352,81872453)the Bio-Pharmaceutical Project of Science and Technology of Shanghai(No.15431901700)the Natural Science Foundation of Shanghai(No.18ZR1438700)the Key Research and Development Program of Ningxia(Nos.2018BFH02001 and 2019BFG02017)。
文摘Radiotherapy is commonly used to treat advanced pancreatic cancers and can improve survival by2 months in combination with gemcitabine.However,prognosis and survival improvement remain unsatisfactory,and effective therapies are urgently needed.Piperlongumine has been demonstrated to have therapeutic potentials against various cancers.In this study,we synthesized a series of piperlongumine derivatives and provided evidence that piperlongumine derivatives could be used as effective radiosensitizers in pancreatic cancer.Two compounds enhanced the radiosensitivity of Panc-1 and SW1990 cells.In a pancreatic bi-flank xenograft tumor model,they significantly inhibited tumor growth.Piperlongumine derivatives could induce reactive oxygen species(ROS)expression and regulate the Keapl-Nrf2 protective pathway with enhancement of radiation-induced DNA damage,G2/M-phase cell cycle arrest,and apoptosis.Collectively,our data offer a proof of concept for the use of piperlongumine derivatives as a novel class of radiosensitizers for the treatment of pancreatic cancer.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39830090).
文摘Riboflavin, suggested to be a radiosensitizer, was studied in murine thymocytes and human hepatoma L02 cell line in vitro with MTT method and fluorescence microscopy. When the murine thymocytes treated with 5-400 μmol/L riboflavin were irradiated by 5 Gy 60Co γ ionizing radiation, the low concentration groups, i.e. treated with 5-50 μmol/L riboflavin, showed a different surviving fractions-time relating correlation compared with the high concentration groups, i.e. treated with 100-400 μmol/L riboflavin. The former had a high survival level at the end of irradiation, but which, after 4-h incubation, decreased rapidly to a low level. On the contrary, the high concentration groups showed a low survival level at the end of irradiation, and a poor correlation was found between the surviving fraction and the incubation time, after 4 h a little difference was observed. The results of fluorescence microscopy indicated that under low concentration conditions, the riboflavin localized mainly in nucleus (both perinuclear area and inside of nuclear membrane), while under high concentration conditions, intensive riboflavin also localized around cytoplasmic membranes. Thus we can conclude: the riboflavin had radiosensitivity effect on DNA under low concentration conditions, and enhanced the damage to cytoplasmic membrane under high concentration conditions. Also the most effective concentration of riboflavin can be evaluated to be approximate 100 μmol/L.
基金supported by the Science and Technology Plan Project of Guangzhou(No.202102010171)National Natural Science Foundation Cultivation Project of The Third Affiliated Hospital of Sun Yat-sen University(No.2020GZRPYMS11)+1 种基金Natural Science Foundation of Guangdong Province(No.2018A030313641)CSCO-Roche Joint Cancer Research Fund(No.Y-Roche2019/20041)。
文摘Primary liver cancer is a significant health problem worldwide.Hepatocellular carcinoma(HCC)is the main pathological type of primary liver cancer,accounting for 75%-85%of cases.In recent years,radiotherapy has become an emerging treatment for HCC and is effective for various stages of HCC.However,radiosensitivity of liver cancer cells has a significant effect on the efficacy of radiotherapy and is regulated by various factors.How to increase radiosensitivity and improve the therapeutic effects of radiotherapy require further exploration.This review summarizes the recent research progress on the mechanisms affecting sensitivity to radiotherapy,including epigenetics,transportation and metabolism,regulated cell death pathways,the microenvironment,and redox status,as well as the effect of nanoparticles on the radiosensitivity of liver cancer.It is expected to provide more effective strategies and methods for clinical treatment of liver cancer by radiotherapy.
文摘AIM:To investigate whether the inhibition of autophagy by chloroquine(CQ)sensitizes rectal tumors to radiation therapy(RT)or concurrent chemoradiation(chemoRT).METHODS:In vitro,HCT-116 and HT-29 colorectal cancer(CRC)cell lines were treated as following:(1)PBS;(2)CQ;(3)5-fluorouracil(5-FU);(4)RT;(5)CQ and RT;(6)5-FU and RT;(7)CQ and 5-FU;and(8)5-FU and CQ and RT.Each group was then exposed to various doses of radiation(0-8 Gy)depending on the experiment.Cell viability and proliferative capacity were measured by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and clonogenic assays.Clonogenic survivalcurves were constructed and compared across treatment groups.Autophagy status was determined by assessing the LC3-Ⅱto LC3-Ⅰratio on western blot analysis,autophagosome formation on electron microscopy and identification of a perinuclear punctate pattern with GFPlabeled LC3 on fluorescence microscopy.Cell cycle arrest and cell death were evaluated by FACS and AnnexinⅤanalysis.All experiments were performed in triplicate and statistical analysis was performed by the student’s t test to compare means between treatment groups.RESULTS:RT(2-8 Gy)induced autophagy in HCT-116and HT-29 CRC cell lines at 4 and 6 h post-radiation,respectively,as measured by increasing LC3-Ⅱto LC3-Ⅰratio on western blot.Additionally,electron microscopy demonstrated autophagy induction in HT-29 cells24 h following irradiation at a dose of 8 Gy.Drug treatment with 5-FU(25μmol/L)induced autophagy and the combination of 5-FU and RT demonstrated synergism in autophagy induction.CQ(10μmol/L)alone and in combination with RT effectively inhibited autophagy and sensitized both HCT-116 and HT-29 cells to treatment with radiation(8 Gy;P<0.001 and 0.00001,respectively).Significant decrease in clonogenic survival was seen only in the HT-29 cell line,when CQ was combined with RT at doses of 2 and 8 Gy(P<0.5 and P=0.05,respectively).There were no differences in cell cycle progression or Annexin V staining upon CQ addition to RT.CONCLUSION:Autophagy inhibition by CQ increases CRC cell sensitivity to concurrent treatment with 5-FU and RT in vitro,suggesting that addition of CQ to chemoRT improves CRC treatment response.
文摘Objective:To explore the influence of silencing Bcl-2 expression by small interfering RNA（siRNA） on Bcl-2 protein expression,cell apoptosis rale and radiosensilivity of gastric cancer BCC823 cells.Methods:siRNA segment for Bcl-2 gene was designed and synthesized,then was induced into gastric cancer BGC 823 cells by liposome transfection.Bcl-2 protein expression was detected by Western Blotting.After X radiation,flow cytometry and clone forming assay were used to determine the effects of RNA interference on BGC823 cell apoptosis rate and radiosensitivity. Result:After the transfection of Bcl-2 siRNA,the positive expression rate of Bcl-2 protein in BGC823 cells was（35.45±2.35）%.Compared with the control group and negative siRNA transfection group,the rate was significantly decreased（P【0.01）.The apoptosis rate of BGC823-RNAi cell was（10.81±0.91）%,which was significantly higher than the control group and negative siRNA transfection group（P【0.01）.After 48h X radiation,the apoptosis rate of BGC823-RNAi was（28.91±1.40）%,which was significantly higher than the control group and the group without radiation （P【0.01）.During clone forming assay D<sub>0</sub>,D<sub>4</sub> and SF<sub>2</sub> values in Bcl-2 siRNA1 transfection group were all lower than those in the control group.The radiosensitivity ratio was 1.28（the ratio of D<sub>0</sub>） and 1.60（the ratio of D<sub>4</sub>）.Conclusions:Specific siRNA of Bcl-2 gene can effectively inhibit the expression of Bcl-2 gene,enhance the radiosensitivity and apoptosis of gastric cancer BGC823 cells,having good clinical application perspective.
基金supported by the National Natural Science Foundation of China(Grant Nos.:81673718 and 82074132)the Technology Project of Guangdong Province(Grant No.:2016A020226034)。
文摘Shengmai Yin(SMY)is a Chinese herbal decoction that effectively alleviates the side effects of radiotherapy in various cancers and helps achieve radiotherapy’s clinical efficacy.In this study,we explored the interaction mechanism among SMY,DNA methylation,and nasopharyngeal carcinoma(NPC).We identified differences in DNA methylation levels in NPC CNE-2 cells and its radioresistant cells(CNE-2R)using the methylated DNA immunoprecipitation array and found that CNE-2R cells showed genomewide changes in methylation status towards a state of hypomethylation.SMY may restore its original DNA methylation status,and thus,enhance radiosensitivity.Furthermore,we confirmed that the differential gene Tenascin-C(TNC)was overexpressed in CNE-2R cells and that SMY downregulated TNC expression.This downregulation of TNC inhibited NPC cell radiation resistance,migration,and invasion.Furthermore,we found that TNC was hypomethylated in CNE-2R cells and partially restored to a hypermethylated state after SMY intervention.DNA methyltransferases 3 a may be the key protein in DNA methylation of TNC.
文摘Curcumin is widely reported to have remarkable medicinal- and antineoplastic- properties. This review details curcumin's relationship with radiotherapy(RT), principally as a radiosensitizer for various malignancies and a radioprotector for normal tissues. First, examples of radiosensitization are provided for various cancers:Pediatric, lymphoma, sarcoma, prostate, gynecologic, pancreas, liver, colorectal, breast, lung, head/neck, and glioma. It is not the purpose of this article to comprehensively review all radiosensitization data; however, high-quality studies are discussed in relationship to currently-controversial RT questions for many cancers, and thus the importance of developing a natural radiosensitizer. Attention is then shifted to radioprotection, for which supporting research is discussed for the following RT toxicities: Dermatitis, pneumonitis, cataractogenesis, neurocognition, myelosuppression, secondary malignancies, and mucositis/enteritis. Though there is fewer data for radioprotection, the overall quality of clinical evidence is higher, and small clinical trials implicating the efficacy of curcumin for RT toxicities(vs placebo/current therapies) are also detailed. Though the overall level of evidence for curcumin as a radiosensitizer and radioprotector is low, it must be recognized that risks of adverse effects are exceedingly low, and clinicians may need to judge the yet-unproven rewards with low toxicity risks.
文摘Objective:Cancer cell radioresistance is a stumbling block in radiation therapy.The activity in the nuclear factor kappa B(NFκB)pathway correlates with anti-apoptotic mechanisms and increased radioresistance.The IKK complex plays a major role in NFκB activation upon numerous signals.In this study,we examined the interaction between ionizing radiation(IR)and different members of the IKK-NFκB pathway,as well as upstream activators,RAF1,ERK,and AKT1.Methods:The effect of 4 Gy of IR on the expression of the RAF1-ERK-IKK-NFκB pathway was examined in A549 and H1299 lung cancer cell lines using Western blot analysis and confocal microscopy.We examined changes in radiation sensitivity using gene silencing or pharmacological inhibitors of ERK and IKKβ.Results:IKKα,IKKγ,and IκBαincreased upon exposure to IR,thereby affecting nuclear levels of NFκB(phospho-p65).ERK inhibition or si RNA-mediated down-regulation of RAF1 suppressed the post-irradiation survival of the examined lung cancer cell lines.A similar effect was detected on survival upon silencing IKKα/IKKγor inhibiting IKKβ.Conclusions:Exposure of lung cancer cells to IR results in NFκB activation via IKK.The genetic or pharmacological blockage of the RAF1-ERK-IKK-NFκB pathway sensitizes cells to therapeutic doses of radiation.Therefore,the IKK pathway is a promising target for therapeutic intervention in combination with radiotherapy.
基金supported by the National Natural Science Foundation of China (82073544 and 81971774)the Chongqing Talent Project (CQYC2019)the Chongqing Chief Expert Program in Medicine (CQYC2018)。
文摘Background:Ultrasound-triggered microbubble destruction(UTMD) is a widely used noninvasive technology in both military and civilian medicine,which could enhance radiosensitivity of various tumors.However,little information is available regarding the effects of UTMD on radiotherapy for glioblastoma or the underlying mechanism.This study aimed to delineate the effect of UTMD on the radiosensitivity of glioblastoma and the potential involvement of autophagy.Methods:GL261,U251 cells and orthotopic glioblastoma-bearing mice were treated with ionizing radiation(IR) or IR plus UTMD.Autophagy was observed by confocal microscopy and transmission electron microscopy.Western blotting and immunofluorescence analysis were used to detect progesterone receptor membrane component 1(PGRMC1),light chain 3 beta 2(LC3B2) and sequestosome 1(SQSTM1/p62) levels.Lentiviral vectors or siRNAs transfection,and fluorescent probes staining were used to explore the underlying mechanism.Results:UTMD enhanced the radiosensitivity of glioblastoma in vitro and in vivo(P<0.01).UTMD inhibited autophagic flux by disrupting autophagosome-lysosome fusion without impairing lysosomal function or autophagosome synthesis in IR-treated glioblastoma cells.Suppression of autophagy by 3-methyladenine,bafilomycin A1 or ATG5 siRNA had no significant effect on UTMD-induced radiosensitization in glioblastoma cells(P<0.05).Similar results were found when autophagy was induced by rapamycin or ATG5 overexpression(P>0.05).Furthermore,UTMD inhibited PGRMC1expression and binding with LC3B2 in IR-exposed glioblastoma cells(P<0.01).PGRMC1 inhibitor AG-205 or PGRMC1siRNA pretreatment enhanced UTMD-induced LC3B2 and p62 accumulation in IR-exposed glioblastoma cells,thereby promoting UTMD-mediated radiosensitization(P<0.05).Moreover,PGRMC1 overexpression abolished UTMD-caused blockade of autophagic degradation,subsequently inhibiting UTMD-induced radiosensitization of glioblastoma cells.Finally,compared with IR plus UTMD group,PGRMC1 overexpression significantly increased tumor size [(3.8±1.1) mm^(2)vs.(8.0±1.9) mm^(2),P<0.05] and decreased survival time [(67.2±2.6) d vs.(40.0±1.2) d,P=0.0026] in glioblastoma-bearing mice.Conclusions:UTMD enhanced the radiosensitivity of glioblastoma partially by disrupting PGRMC1-mediated autophagy.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.31670859,81772243,81803172,81803167,31800703,and 31900889)the CAMS Innovation Fund for Medical Science(Grant No.2017-I2M-1-016)+4 种基金the China Postdoctoral Science Foundation(Grant No.2018M630106)the Natural Science Foundation of Tianjin(Grant Nos.18JCYBJC26800,18JCQNJC12300,and 17JCYBJC42700)the Fundamental Research Funds for the Central Universities(Grant No.10023201601602)the Non-profit Central Research Institute Fund of the Chinese Academy of Medical Sciences(Grant Nos.2017-1001-08 and 2018RC310020)the Key R&D Program of Shandong Province(Grant No.2019GSF107056).
文摘Objective:We aimed to investigate the radiosensitizing efficacy of the poly-ADP-ribose polymerase(PARP)inhibitor,olaparib,and the Bloom syndrome protein(BLM)helicase inhibitor,ML216,in non-small cell lung cancer(NSCLC)cells.Methods:Radiosensitization of NSCLC cells was assessed by colony formation and tumor growth assays.Mechanistically,the effects of ML216,olaparib,and radiation on cell and tumor proliferation,DNA damage,cell cycle,apoptosis,homologous recombination(HR)repair,and non-homologous end joining(NHEJ)repair activity were determined.Results:Both olaparib and ML216 enhanced the radiosensitivities of olaparib-sensitive H460 and H1299 cells,which was seen as decreased surviving fractions and Rad51 foci,increased total DNA damage,andγH2AX and 53BP1 foci(P<0.05).The expressions of HR repair proteins were remarkably decreased in olaparib-treated H460 and H1299 cells after irradiation(P<0.05),while olaparib combined with ML216 exerted a synergistic radiosensitization effect on olaparib-resistant A549 cells.In addition to increases of double strand break(DSB)damage and decreases of Rad51 foci,olaparib combined with ML216 also increased pDNA-PKcs(S2056)foci,abrogated G2 cell cycle arrest,and induced apoptosis in A549 lung cancer after irradiation in vitro and in vivo(P<0.05).Moreover,Western blot showed that olaparib combined with ML216 and irradiation inhibited HR repair,promoted NHEJ repair,and inactivated cell cycle checkpoint signals both in vitro and in vivo(P<0.05).Conclusions:Taken together,these results showed the efficacy of PARP and BLM helicase inhibitors for radiosensitizing NSCLC cells,and supported the model that BLM inhibition sensitizes cells to PARP inhibitor-mediated radiosensitization,as well as providing the basis for the potential clinical development of this combination for tumors intrinsically resistant to PARP inhibitors and radiotherapy.
