In order to evaluate the effect of mitofusin-2 gene （mfn2） on proliferation and chemotherapy sensitivity of human breast carcinoma cell line MCF-7 in vitro, pEGFPmfn2 plasmid carrying full length of mitofusin-2 gene...In order to evaluate the effect of mitofusin-2 gene （mfn2） on proliferation and chemotherapy sensitivity of human breast carcinoma cell line MCF-7 in vitro, pEGFPmfn2 plasmid carrying full length of mitofusin-2 gene was transfected, by using sofast, into MCF-7 cells. Mitofusin-2 gene expression in MCF-7 cells transfected by sofast after 48 h was detected by PCR and Western blotting, and the stable expression of GFP protein in MCF-7 cells by Western blot analysis. The proliferation of MCF-7 cells was assayed by MTT and cell counting. By using PI method, the effects of mfn2 on the cell cycle distribution of MCF-7 were measured. Annexin-Ⅴ/PI double labeling method was employed to detect the changes in apoptosis induced by chemotherapeutics before and after transfection. The results showed that the MCF-7 cells transfected with mfn2 gene could stably and highly express GFP protein. MTT assay revealed that after transfection of mfn2 cDNA, the proliferation of MCF-7 cells was significantly inhibited. DNA histogram showed that cells arrested in S phase, and the percentage of S phase cells was 42.7, 17.2 and 19.6 in mfn2 cDNA transfection group, blank plasmid transfection group and blank control group, respectively （P〈0.05）. The apoptosis ratio of the cells transfected with mfn2 gene was increased from 3.56% to 15.95%, that of the cells treated with camptothecin （CAMP） followed by mfn2 gene transfection was 69.6%, and that in blank plasmid transfection group and blank control group was 31.0% and 23.4% respectively （P〈0.05）. It was suggested that transfection of mfn2 gene could significantly inhibit the proliferation of MCF-7 cells and promote their sensitivity to CAMP with a synergic effect.展开更多
Relapse and metastasis are frequent in colon cancer and may be linked to stem cell characteristics.This study isolated side population（SP） cells from a colon cancer cell line（Colo-320） and examined their self-rene...Relapse and metastasis are frequent in colon cancer and may be linked to stem cell characteristics.This study isolated side population（SP） cells from a colon cancer cell line（Colo-320） and examined their self-renewal and differentiation abilities.Compared to non-SP（NSP） cells,SP colon cancer cells were more tumorigenic in vivo and exhibited more invasive characteristics and a greater ability to form colonies.Additionally,more cells were in G0/G1 phase and more highly expressed the multidrug resistance protein BCRP/ABCG2.We achieved enhanced chemotherapy sensitivity by transfecting SP cells with a hairpin-like,small interfering RNA（si RNA） eukaryotic expression plasmid targeting BCRP/ABCG2.展开更多
Since most patients with ovarian cancer are in the advanced stage when they are prone to recurrence,it is difficult to detect and treat ovarian cancer.There are tumor serum markers in the ascites.Therefore,the study e...Since most patients with ovarian cancer are in the advanced stage when they are prone to recurrence,it is difficult to detect and treat ovarian cancer.There are tumor serum markers in the ascites.Therefore,the study explored the correlation between the serum marker levels of the ascites and chemotherapy sensitivity in patients with ovarian malignant tumors.First,50 patients with nested cancer were selected as research subjects and received treatment,and then immediately 200 mg carboplatin+100 mL normal saline was placed in the abdominal cavity of all patients,which was equivalent to an intraperitoneal chemotherapy.Carboplatin+docetaxel combined with intravenous chemotherapy was started 3 weeks after surgery,and chemotherapy was given every 3 weeks for a total of 5 to 6 courses.The serum levels of CA125,CA199,CEA and AFP in peripheral blood and peripheral blood were determined by ELISA.The results showed that the levels of CA125,CA199,CEA and AFP in serum and ascites after chemotherapy were lower than before chemotherapy(P<0.05).The short-term effective rate of 50 ovarian cancer patients(8 CR,28 PR,12 SD,2 PD)was 72.00%.Therefore,patients with ovarian malignant tumors had a good short-term curative effect after chemotherapy,which can reduce the ascites and serum levels of CA125,CA199,CEA,AFP for clinical reference value dual-mode MRI nanoparticle-mediated photothermal therapy showed good application potential in tumor treatment and diagnosis.展开更多
Acute myeloid leukemia(AML)is a common hematological malignancy with overall poor prognosis.Exploring novel targets is urgent and necessary to improve the clinical outcome of relapsed and refractory(RR)AML patients.Th...Acute myeloid leukemia(AML)is a common hematological malignancy with overall poor prognosis.Exploring novel targets is urgent and necessary to improve the clinical outcome of relapsed and refractory(RR)AML patients.Through clinical specimens,animal models and cell-level studies,we explored the specific mechanism of 3-hydroxy-3-methylglutaryl coenzyme A synthase 1(HMGCS1)in AML and the mechanism of targeting HMGCS1 to attenuate cell proliferation,increase chemotherapy sensitivity and improve the occurrence and development of AML.Here,we reveal that HMGCS1 is overexpressed in RR patients and negatively related to overall survival(OS).Knocking out HMGCS1 in AML cells attenuated cell proliferation and increased chemotherapy sensitivity,while stable overexpression of HMGCS1 had the opposite effects.Mechanistically,we identified that knockout of HMGCS1 suppressed mitogen-activated protein kinase(MAPK)pathway activity,while overexpression of HMGCS1 could remarkably enhance the pathway.U0126,a MEK1 inhibitor,offset the effects of HMGCS1 overexpression,indicating that HMGCS1 promotes RR AML through the MAPK pathway.Further,we verified that hymeglusin,a specific inhibitor of HMGCS1,decreases cell growth both in AML cell lines and primary bone marrow cells of AML patients.Furthermore,combination of hymeglusin and the common chemotherapeutic drug cytarabine and adriamycin(ADR)had synergistic toxic effects on AML cells.Our study demonstrates the important role of HMGCS1 in AML,and targeting this protein is promising for the treatment of RR AML.展开更多
The effects of insulin or insulin in combination with chemotherapeutic drugs on the proliferation and apoptosis of endometrial carcinoma cells were examined with an aim to determine the efficacy and safety of insulin ...The effects of insulin or insulin in combination with chemotherapeutic drugs on the proliferation and apoptosis of endometrial carcinoma cells were examined with an aim to determine the efficacy and safety of insulin in endometrial cancer therapy.Ishikawa and Hec-1A cells were treated with insulin and/or paclitaxel.Cell proliferation was assessed by MTT assay.Cell cycle and cell apoptosis were determined by flow cytometry (FCM).Survivin gene expression was detected by RT-PCR.Our results showed that in a certain range of working concentrations and action time, insulin could mildly augment cell proliferation and the percentage of S phase cells in endometrial cancer (Ishikawa/Hec-1A) cells.Insulin plus paclitaxel (combination group) could significantly inhibit cell proliferation (69.38%±2.32% vs 40.31%±4.52% with Ishikawa; 64.11%±6.33% vs 45.89%±3.27% with Hec-1A) and increase cell apoptosis compared with treatment with paclitaxel alone (paclitaxel group).Survivin gene expression was also significantly decreased in combination group as compared with paclitaxel group.We are led to conclude that insulin can mildly augment cell proliferation and present chemotherapy sensitivity in endometrial cancer cells.Insulin can be to used safely and efficiently in endometrial cancer therapy.展开更多
Objective:Organoids have recently been used as in vitro models to screen chemotherapy drugs in combination with hyperthermia treatment in colorectal cancer.Our research aimed to establish a library of patient-derived ...Objective:Organoids have recently been used as in vitro models to screen chemotherapy drugs in combination with hyperthermia treatment in colorectal cancer.Our research aimed to establish a library of patient-derived colorectal cancer organoids to evaluate synergism between chemotherapy drugs and hyperthermia;validate an index of the hyperthermia chemotherapy sensitization enhancement ratio(HCSER)to identify the chemotherapeutics most enhanced by hyperthermia;and recommend chemotherapy drugs for hyperthermic intraperitoneal treatment.Methods:Organoids were grown from cells extracted from colorectal cancer patient samples or colorectal cancer cell lines.Cells from both sources were encapsulated in 3 D Matrigel droplets,which were formulated in microfluidics and phase-transferred into identical cell-laden Matrigel microspheres.The microspheres were seeded in 96-well plates,with each well containing a single microsphere that developed into an organoid after 7 days.The organoids were used to evaluate the efficacy of chemotherapy drugs at both 37℃ as a control and 43℃ for 90 min to examine hyperthermia synergism.Cell viability was counted with 10%CCK8.Results:We successfully established a library of colorectal cancer organoids from 22 patient parental tumors.We examined the hyperthermia synergism of 7 commonly used hyperthermic intraperitoneal chemotherapy drugs.In 11 of the 22 patient organoids,raltitrexed had significant hyperthermia synergism,which was indexed as the highest HCSER score within each patient group.Conclusions:Our results primarily demonstrated the use of patient-derived colorectal cancer organoids as in vitro models to evaluate hyperthermia synergistic chemotherapeutics.We found that hyperthermia enhanced the effect of raltitrexed the most among the common anti-colorectal cancer drugs.展开更多
Lysine-specific demethylase 1 （LSD1） was the first histone demethylase identified as catalysing the removal of mono- and di-methylation marks on histone H3-K4. Despite the potential broad action of LSD1 in transcrip...Lysine-specific demethylase 1 （LSD1） was the first histone demethylase identified as catalysing the removal of mono- and di-methylation marks on histone H3-K4. Despite the potential broad action of LSD1 in transcription regulation, recent studies indicate that LSD1 may coordinate with multiple epigenetic regulatory complexes including CoREST/HDAC complex, NuRD complex, SIRT1, and PRC2, implying complicated mechanistic actions of this seemingly simple enzyme. Here, we report that LSD1 is also an integral component of the SIN3A/HDAC complex. Transcriptional target analysis using ChIP-on-chip technology revealed that the LSD1/SIN3A/HDAC complex targets several cellular signalling pathways that are critically involved in cell proliferation, survival, metastasis, and apoptosis, especially the p53 signalling pathway. We have demonstrated that LSD1 coordinates with the SIN3A/HDAC complex in inhibiting a series of genes such as CASP7, TGFB2, CDKN1A（p21）, HIF1A, TERT, and MDM2, some of which are oncogenic. Our experiments also found that LSD1 and SIN3A are required for optimal survival and growth of breast cancer cells while also essential for the maintenance of epithelial homoeostasis and chemosensitivity. Our data indicate that LSD1 is a functional alternative subunit of the SIN3A/HDAC complex, providing a molecular basis for the interplay of histone demethylation and deacetylation in chromatin remodelling, and suggest that the LSD1/SIN3A/HDAC complex could be a target for breast cancer therapeutic strategies.展开更多
Background Chemoresistance is common among patients with esophageal squamous cell carcinoma （ESCC）.We investigated the effect and mechanism of insulin on enhancing anticancer functions of cisplatin in human esophage...Background Chemoresistance is common among patients with esophageal squamous cell carcinoma （ESCC）.We investigated the effect and mechanism of insulin on enhancing anticancer functions of cisplatin in human esophageal cancer cell line EC9706.Methods The viability of EC9706 cells exposed to cisplatin was assessed using MTT assay.The times T1,when the number of living cells reached a plateau and T2,when the number of living cells reached a new plateau after the addition of insulin were found.T1 and T2 plateau cells were stained by Annexin V-FITC/PI and monodansylcadaverin （MDC）.Fluorescent microscopy was used to observe the expression of apoptosis and autophagy intuitively.Apoptotic ratio and fluorescent intensity were analysed by flow cytometry （FCM） quantitatively.Western blotting analysis was used to estimate the protein expression levels of AKT,mTOR,PI3K,PTEN,autophage related indicator LC3-Ⅱ and autophage related protein Beclin1 changes that occurred in the course of treatment.Results A larger number of typical autophagosomes were detected in EC9706 cells exposed to cisplatin.Insulin can increase the apoptosis induced by cisplatin.Apoptotic ratio of T1 plateau cells （（32.6±4.3）％） is significantly less than T2 plateau （（47.5±5.6）％）.MDC fluorescent intensity at T1 plateau （104.9±13.2） was significantly higher than intensity at T2 plateau （82.6±10.3）.After cotreatment with insulin,the expression level of LC3-Ⅱ,Beclin1 and PTEN in T2 plateau cells were significantly downregulated,but AKT,mTOR and PI3K expressions significantly upregulated compared with T1 plateau.Conclusions Insulin could enhance cisplatin-induced apoptosis in human esophageal squamous cell carcinoma EC9706 cells related to inhibition of autophagy.The activation of PI3K/Akt/mTOR signaling pathway induced by insulin resulted in the suppression of autophagy in EC9706 cells,which may be attributed to the anticancer effects of cisplatin.展开更多
OBJECTIVE： To study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells. METHODS： EC9706 cells were treated in the follow- ing six groups： blank group （n...OBJECTIVE： To study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells. METHODS： EC9706 cells were treated in the follow- ing six groups： blank group （no transfection）, nega- tive control group （transfection no-carrier）, trans- fection group （transfected with pSilencer-siK-ras）, taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and west- ern blotting were used to analyze the expression of MAPK1 （mitogen-activated protein kinases 1） and cyclin D1 in response to siRNA （small interfering RNA） transfection and taxol treatment. RESULTS： K-Ras （K-Ras gene） siRNA transfection of EC9706 esophageal squamous carcinoma cells de- creased the expression of K-Ras, MAPK1 and cyclinD1 at the mRNA and protein level. Reverse tran- scription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group （P〈0.05）. Western blotting showed that 72 h after EC9706 cell trans- fection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the ex- pression levels in the transfection group were sig- nificantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as com- pared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe. CONCLUSION： Apoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-me- diated inhibition of Ras signaling, with the most ob- vious increase observed in the transfection plus tax- ol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeu- tic agent, taxol. Ras knockdown also down-regulat- ed the expression of the downstream genes, MAPKI and cyclin DI, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells.展开更多
基金a grant of the Clinical Key Subject Foundation from Ministry of Health of China (No. 2004CB518705)
文摘In order to evaluate the effect of mitofusin-2 gene （mfn2） on proliferation and chemotherapy sensitivity of human breast carcinoma cell line MCF-7 in vitro, pEGFPmfn2 plasmid carrying full length of mitofusin-2 gene was transfected, by using sofast, into MCF-7 cells. Mitofusin-2 gene expression in MCF-7 cells transfected by sofast after 48 h was detected by PCR and Western blotting, and the stable expression of GFP protein in MCF-7 cells by Western blot analysis. The proliferation of MCF-7 cells was assayed by MTT and cell counting. By using PI method, the effects of mfn2 on the cell cycle distribution of MCF-7 were measured. Annexin-Ⅴ/PI double labeling method was employed to detect the changes in apoptosis induced by chemotherapeutics before and after transfection. The results showed that the MCF-7 cells transfected with mfn2 gene could stably and highly express GFP protein. MTT assay revealed that after transfection of mfn2 cDNA, the proliferation of MCF-7 cells was significantly inhibited. DNA histogram showed that cells arrested in S phase, and the percentage of S phase cells was 42.7, 17.2 and 19.6 in mfn2 cDNA transfection group, blank plasmid transfection group and blank control group, respectively （P〈0.05）. The apoptosis ratio of the cells transfected with mfn2 gene was increased from 3.56% to 15.95%, that of the cells treated with camptothecin （CAMP） followed by mfn2 gene transfection was 69.6%, and that in blank plasmid transfection group and blank control group was 31.0% and 23.4% respectively （P〈0.05）. It was suggested that transfection of mfn2 gene could significantly inhibit the proliferation of MCF-7 cells and promote their sensitivity to CAMP with a synergic effect.
基金supported by grants from the National Nature Science Foundation of China(No.81101870)the National Key Clinical Specialist Construction Programs of China(No.2013-544)the Key Programs of National Health and Family Planning Commission of Tianjin(No.16KG127)
文摘Relapse and metastasis are frequent in colon cancer and may be linked to stem cell characteristics.This study isolated side population（SP） cells from a colon cancer cell line（Colo-320） and examined their self-renewal and differentiation abilities.Compared to non-SP（NSP） cells,SP colon cancer cells were more tumorigenic in vivo and exhibited more invasive characteristics and a greater ability to form colonies.Additionally,more cells were in G0/G1 phase and more highly expressed the multidrug resistance protein BCRP/ABCG2.We achieved enhanced chemotherapy sensitivity by transfecting SP cells with a hairpin-like,small interfering RNA（si RNA） eukaryotic expression plasmid targeting BCRP/ABCG2.
文摘Since most patients with ovarian cancer are in the advanced stage when they are prone to recurrence,it is difficult to detect and treat ovarian cancer.There are tumor serum markers in the ascites.Therefore,the study explored the correlation between the serum marker levels of the ascites and chemotherapy sensitivity in patients with ovarian malignant tumors.First,50 patients with nested cancer were selected as research subjects and received treatment,and then immediately 200 mg carboplatin+100 mL normal saline was placed in the abdominal cavity of all patients,which was equivalent to an intraperitoneal chemotherapy.Carboplatin+docetaxel combined with intravenous chemotherapy was started 3 weeks after surgery,and chemotherapy was given every 3 weeks for a total of 5 to 6 courses.The serum levels of CA125,CA199,CEA and AFP in peripheral blood and peripheral blood were determined by ELISA.The results showed that the levels of CA125,CA199,CEA and AFP in serum and ascites after chemotherapy were lower than before chemotherapy(P<0.05).The short-term effective rate of 50 ovarian cancer patients(8 CR,28 PR,12 SD,2 PD)was 72.00%.Therefore,patients with ovarian malignant tumors had a good short-term curative effect after chemotherapy,which can reduce the ascites and serum levels of CA125,CA199,CEA,AFP for clinical reference value dual-mode MRI nanoparticle-mediated photothermal therapy showed good application potential in tumor treatment and diagnosis.
基金supported by the National Natural Science Foundation of China to H.Z.(Grant Nos.81770184,81970143,and 82270167)and L.Z.(Grant No.81800174)the Talent Young Program of Guangdong Province(2021B1515020017),and the Leading Talents Program from The First Affiliated Hospital of Jinan University to H.Z.
文摘Acute myeloid leukemia(AML)is a common hematological malignancy with overall poor prognosis.Exploring novel targets is urgent and necessary to improve the clinical outcome of relapsed and refractory(RR)AML patients.Through clinical specimens,animal models and cell-level studies,we explored the specific mechanism of 3-hydroxy-3-methylglutaryl coenzyme A synthase 1(HMGCS1)in AML and the mechanism of targeting HMGCS1 to attenuate cell proliferation,increase chemotherapy sensitivity and improve the occurrence and development of AML.Here,we reveal that HMGCS1 is overexpressed in RR patients and negatively related to overall survival(OS).Knocking out HMGCS1 in AML cells attenuated cell proliferation and increased chemotherapy sensitivity,while stable overexpression of HMGCS1 had the opposite effects.Mechanistically,we identified that knockout of HMGCS1 suppressed mitogen-activated protein kinase(MAPK)pathway activity,while overexpression of HMGCS1 could remarkably enhance the pathway.U0126,a MEK1 inhibitor,offset the effects of HMGCS1 overexpression,indicating that HMGCS1 promotes RR AML through the MAPK pathway.Further,we verified that hymeglusin,a specific inhibitor of HMGCS1,decreases cell growth both in AML cell lines and primary bone marrow cells of AML patients.Furthermore,combination of hymeglusin and the common chemotherapeutic drug cytarabine and adriamycin(ADR)had synergistic toxic effects on AML cells.Our study demonstrates the important role of HMGCS1 in AML,and targeting this protein is promising for the treatment of RR AML.
文摘The effects of insulin or insulin in combination with chemotherapeutic drugs on the proliferation and apoptosis of endometrial carcinoma cells were examined with an aim to determine the efficacy and safety of insulin in endometrial cancer therapy.Ishikawa and Hec-1A cells were treated with insulin and/or paclitaxel.Cell proliferation was assessed by MTT assay.Cell cycle and cell apoptosis were determined by flow cytometry (FCM).Survivin gene expression was detected by RT-PCR.Our results showed that in a certain range of working concentrations and action time, insulin could mildly augment cell proliferation and the percentage of S phase cells in endometrial cancer (Ishikawa/Hec-1A) cells.Insulin plus paclitaxel (combination group) could significantly inhibit cell proliferation (69.38%±2.32% vs 40.31%±4.52% with Ishikawa; 64.11%±6.33% vs 45.89%±3.27% with Hec-1A) and increase cell apoptosis compared with treatment with paclitaxel alone (paclitaxel group).Survivin gene expression was also significantly decreased in combination group as compared with paclitaxel group.We are led to conclude that insulin can mildly augment cell proliferation and present chemotherapy sensitivity in endometrial cancer cells.Insulin can be to used safely and efficiently in endometrial cancer therapy.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.81972918 and 61971255)Shenzhen Science and Technology Innovation Committee(Grant No.KQJSCX20180327143623167)+2 种基金NANJING CHIA TAI TIANQING Company,Foundation for Young Innovative Talents in Education of Guangdong(Grant No.2017KQNCX161)Natural Science Foundation of Guangdong Province(Grant No.2018A030310249)Key Clinical Technique of Guangzhou(Grant No.2019ZD16)。
文摘Objective:Organoids have recently been used as in vitro models to screen chemotherapy drugs in combination with hyperthermia treatment in colorectal cancer.Our research aimed to establish a library of patient-derived colorectal cancer organoids to evaluate synergism between chemotherapy drugs and hyperthermia;validate an index of the hyperthermia chemotherapy sensitization enhancement ratio(HCSER)to identify the chemotherapeutics most enhanced by hyperthermia;and recommend chemotherapy drugs for hyperthermic intraperitoneal treatment.Methods:Organoids were grown from cells extracted from colorectal cancer patient samples or colorectal cancer cell lines.Cells from both sources were encapsulated in 3 D Matrigel droplets,which were formulated in microfluidics and phase-transferred into identical cell-laden Matrigel microspheres.The microspheres were seeded in 96-well plates,with each well containing a single microsphere that developed into an organoid after 7 days.The organoids were used to evaluate the efficacy of chemotherapy drugs at both 37℃ as a control and 43℃ for 90 min to examine hyperthermia synergism.Cell viability was counted with 10%CCK8.Results:We successfully established a library of colorectal cancer organoids from 22 patient parental tumors.We examined the hyperthermia synergism of 7 commonly used hyperthermic intraperitoneal chemotherapy drugs.In 11 of the 22 patient organoids,raltitrexed had significant hyperthermia synergism,which was indexed as the highest HCSER score within each patient group.Conclusions:Our results primarily demonstrated the use of patient-derived colorectal cancer organoids as in vitro models to evaluate hyperthermia synergistic chemotherapeutics.We found that hyperthermia enhanced the effect of raltitrexed the most among the common anti-colorectal cancer drugs.
基金This work was supported by grants from the Major State Basic Research Development Program of China （2016YFA0102400 to Y.W.）, the National Natural Science Foundation of China （81773017 and 81472733 to Y.W., 81402334 to Y.Y., and 81502446 to R.Q.）, China Postdoctoral Science Foundation （2014M561192 and 2015T80224 to Y.Y.）, the Tianjin Municipal Science and Technology Commission （15JCQNJC11900 to Y.Y.）, and the Science ＆ Technology Development Fund of Tianjin Education Commission for Higher Education （20140105 to R.Q.）.
文摘Lysine-specific demethylase 1 （LSD1） was the first histone demethylase identified as catalysing the removal of mono- and di-methylation marks on histone H3-K4. Despite the potential broad action of LSD1 in transcription regulation, recent studies indicate that LSD1 may coordinate with multiple epigenetic regulatory complexes including CoREST/HDAC complex, NuRD complex, SIRT1, and PRC2, implying complicated mechanistic actions of this seemingly simple enzyme. Here, we report that LSD1 is also an integral component of the SIN3A/HDAC complex. Transcriptional target analysis using ChIP-on-chip technology revealed that the LSD1/SIN3A/HDAC complex targets several cellular signalling pathways that are critically involved in cell proliferation, survival, metastasis, and apoptosis, especially the p53 signalling pathway. We have demonstrated that LSD1 coordinates with the SIN3A/HDAC complex in inhibiting a series of genes such as CASP7, TGFB2, CDKN1A（p21）, HIF1A, TERT, and MDM2, some of which are oncogenic. Our experiments also found that LSD1 and SIN3A are required for optimal survival and growth of breast cancer cells while also essential for the maintenance of epithelial homoeostasis and chemosensitivity. Our data indicate that LSD1 is a functional alternative subunit of the SIN3A/HDAC complex, providing a molecular basis for the interplay of histone demethylation and deacetylation in chromatin remodelling, and suggest that the LSD1/SIN3A/HDAC complex could be a target for breast cancer therapeutic strategies.
文摘Background Chemoresistance is common among patients with esophageal squamous cell carcinoma （ESCC）.We investigated the effect and mechanism of insulin on enhancing anticancer functions of cisplatin in human esophageal cancer cell line EC9706.Methods The viability of EC9706 cells exposed to cisplatin was assessed using MTT assay.The times T1,when the number of living cells reached a plateau and T2,when the number of living cells reached a new plateau after the addition of insulin were found.T1 and T2 plateau cells were stained by Annexin V-FITC/PI and monodansylcadaverin （MDC）.Fluorescent microscopy was used to observe the expression of apoptosis and autophagy intuitively.Apoptotic ratio and fluorescent intensity were analysed by flow cytometry （FCM） quantitatively.Western blotting analysis was used to estimate the protein expression levels of AKT,mTOR,PI3K,PTEN,autophage related indicator LC3-Ⅱ and autophage related protein Beclin1 changes that occurred in the course of treatment.Results A larger number of typical autophagosomes were detected in EC9706 cells exposed to cisplatin.Insulin can increase the apoptosis induced by cisplatin.Apoptotic ratio of T1 plateau cells （（32.6±4.3）％） is significantly less than T2 plateau （（47.5±5.6）％）.MDC fluorescent intensity at T1 plateau （104.9±13.2） was significantly higher than intensity at T2 plateau （82.6±10.3）.After cotreatment with insulin,the expression level of LC3-Ⅱ,Beclin1 and PTEN in T2 plateau cells were significantly downregulated,but AKT,mTOR and PI3K expressions significantly upregulated compared with T1 plateau.Conclusions Insulin could enhance cisplatin-induced apoptosis in human esophageal squamous cell carcinoma EC9706 cells related to inhibition of autophagy.The activation of PI3K/Akt/mTOR signaling pathway induced by insulin resulted in the suppression of autophagy in EC9706 cells,which may be attributed to the anticancer effects of cisplatin.
基金Supported by the Natural Science Research Program of the Education Department of Henan Province(No.2011B320012)
文摘OBJECTIVE： To study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells. METHODS： EC9706 cells were treated in the follow- ing six groups： blank group （no transfection）, nega- tive control group （transfection no-carrier）, trans- fection group （transfected with pSilencer-siK-ras）, taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and west- ern blotting were used to analyze the expression of MAPK1 （mitogen-activated protein kinases 1） and cyclin D1 in response to siRNA （small interfering RNA） transfection and taxol treatment. RESULTS： K-Ras （K-Ras gene） siRNA transfection of EC9706 esophageal squamous carcinoma cells de- creased the expression of K-Ras, MAPK1 and cyclinD1 at the mRNA and protein level. Reverse tran- scription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group （P〈0.05）. Western blotting showed that 72 h after EC9706 cell trans- fection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the ex- pression levels in the transfection group were sig- nificantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as com- pared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe. CONCLUSION： Apoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-me- diated inhibition of Ras signaling, with the most ob- vious increase observed in the transfection plus tax- ol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeu- tic agent, taxol. Ras knockdown also down-regulat- ed the expression of the downstream genes, MAPKI and cyclin DI, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells.
