AIM: To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism.METHODS: MTT assay was applied in the detection of the inhibitory effe...AIM: To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism.METHODS: MTT assay was applied in the detection of the inhibitory effects of genistein on cell proliferation. Flow cytometry was used to analyze the cell cycle distribution.Immunocytochemical technique and Western blotting were performed to detect the protein expression of cyclin D1,cyclin B1 and p21waf1/cip1.RESULTS: Genistein significantly inhibited the growth and proliferation of human gastric carcinoma cells (SGC-7901).Seven days after treatment with different concentrations of genistein (2.5, 5.0, 10.0, 20.0 μg/mL), the growth inhibitory rates were 11.2%, 28.8%, 55.3%, 84.7%respectively and cell cycles were arrested at the G(2)/Mphase. Genistein decreased cyclin D1 protein expression and enhanced cyclin B1 and p21waf/cip1 protein expression in a concentration-dependent manner.CONCLUSION: The growth and proliferation of SGC-7901 cells can be inhibited by genistein via blocking the cell cycle,with reduced expression of cyclin D1 and enhanced expression of cyclin B1 and p21waf/cip1 protein in the concentration range of 0-20 μg/mL.展开更多
AIM: To explore the effects of endothelin-1(ET-1) on hepatic stellate cells (HSCs) DNA uptake, DNA synthesis,collagen synthesis and secretion, inward whole-cell calcium concentration ([Ca^2+]i) as well as the blocking...AIM: To explore the effects of endothelin-1(ET-1) on hepatic stellate cells (HSCs) DNA uptake, DNA synthesis,collagen synthesis and secretion, inward whole-cell calcium concentration ([Ca^2+]i) as well as the blocking effect of verapamil on ET-l-stimulated release of inward calcium(Ca2+) of HSC in vitro.METHODS: Rat hepatic stellate cells (HSCs) were isolated and cultivated. ^3H-TdR and ^3H-proline incorporation used for testing DNA uptake and synthesis, collagen synthesis and secretion of HSCs cultured in vitro;, Fluorescent calcium indicator Fura-2/AM was used to measure [Ca^2+]i inwardHSCs.RESULTS: ET-1 at the concentration of 5×10^-8 mol/L,caused significant increase both in HSC DNA synthesis (2 247+344 cpm, P<0.05) and DNA uptake (P<0.05) when compared with the control group. ET-1 could also increase collagen synthesis (P<0.05 vs control group) and collagen secretion (P<0.05 vscontrol group). Besides, inward HSC [Ca^2+]i reached a peak concentration (422±98 mol/L, P<0.001)at 2 min and then went down slowly to165+51 mol/L(P<0.01) at 25 min from resting state (39±4 mol/L)after treated with ET-1. Verapamil (5 mol/L) blocked ET-1-activated [Ca^2+li inward HSCs compared with control group(P<0.05). Fura-2/AM loaded HSC was suspended in no Ca^2+ buffer containing 1 mol/L EGTA, 5 rain later, 10^-8 mol/L of ET-1 was added, [Ca^2+]i inward HSCs rose from resting state to peak 399±123 mol/L, then began to come down by the time of 20 min. It could also raise [Ca^2+]i inward HSCs even without Ca^2+ in extracellular fluid, and had a remarkable dose-effect relationship(P<0.05). Meanwhile,verapamil could restrain the action of ET-1(P<0.05).CONCLUSION: Actions of ET-1 on collagen metabolism of HSCs may depend on the transportation of inward wholecell calcium.展开更多
AIM: Liver fibrosis is a common pathological process of chronic liver diseases. Activation of hepatic stellate cells(HSCs) is the key issue in the occurrence of liver fibrosis. In this study, we observed the inhibitor...AIM: Liver fibrosis is a common pathological process of chronic liver diseases. Activation of hepatic stellate cells(HSCs) is the key issue in the occurrence of liver fibrosis. In this study, we observed the inhibitory action of rat serum containing Biejiajian oral liquid (BOL), a decoction of turtle shell, on proliferation of rat HSCs, and to explore the antihepatofibrotic mechanisms of BOL.METHODS: A rat model of hepatic fibrosis was induced by subcutaneous injection of CC14. Serum containing low,medium and high dosages of BOL was prepared respectively.Normal and fibrotic HSCs were isolated and cultured. The effect of sera containing BOL on proliferation of HSCs was determined by 3H-TdR incorporation.RESULTS: The inhibitory rate of normal rat HSC proliferation caused by 100 mL/mL sera containing medium and high dosages of BOL showed a remarkable difference as compared with that caused by colchicine (medium dosage group:34.56±4.21% vs29.12±2.85%, P<0.01; high dosage group:37.82±1.32% vs29.12±2.85%, P<0.01). The inhibitory rate of fibrotic rat HSC proliferation caused by 100 mL/L serum containing medium and high dosages of BOL showed a remarkable difference as compared with that caused by colchicine (medium dosage group: 51.31_+3.14% vs 38.32_+2.65%,P<0.01; high dosage group: 60.15_+5.36% vs38.32_+2.65%,P<0.01). The inhibitory rate of normal rat HSC proliferation caused by 100 mL/L and 200 mL/L sera containing a medium dosage of BOL showed a significant difference as compared with that caused by 50 mL/L (100 mL/L group: 69.02±9.96%vs 50.82±9.28%, P<0.05; 200 mL/L group: 81.78±8.92%vs50.82±9.28%, P<0.01). The inhibitory rate of fibrotic rat HSC proliferation caused by 100 mL/L and 200 mL/L sera containing a medium dosage of BOL showed a significant difference as compared with that caused by 50 mL/L (100 mL/L group:72.19±10.96% vs 61.38±7.16%, P<0.05; 200 mL/L group:87.16±8.54% vs 61.38±7.16%, P<0.01).CONCLUSION: Rat serum containing BOL can inhibit proliferation of rat HSCs, and the inhibition depends on the dosage and concentration of BOL. The inhibitory effect on HSC proliferation is one of the main anti-hepatofibroticmechanisms of BOL.展开更多
AIM: To investigate the inhibitory effect of ubiquitin-proteasome pathway (UPP) on proliferation of esophageal carcinoma cells.METHODS: Esophageal carcinoma cell strain EC9706 was treated with MG-132 to inhibit its UP...AIM: To investigate the inhibitory effect of ubiquitin-proteasome pathway (UPP) on proliferation of esophageal carcinoma cells.METHODS: Esophageal carcinoma cell strain EC9706 was treated with MG-132 to inhibit its UPP specificity. Cell growth suppression was evaluated with 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. DNA synthesis was evaluated by ^3H-thymidine (^3H-TdR) incorporation. Morphologic changes of cells were observed under microscope. Activity of telomerase was examined by telomeric repeat amplification protocol (TRAP) of PCRELISA. Cell cycle and apoptosis were detected by flow cytometry (FCM). DNA fragment analysis was used to confirm the presence of apoptosis. Expression of p27^kip1 was detected by immunocytochemical technique. RESULTS: After exposed to MG-132, the growth and value of ^3H-TdR incorporation of EC9706 cells were obviously inhibited. Cells became round, small and exfoliative under microscope. TRAP PCR-ELISA showed that light absorption of cells gradually decreased after exposed to 5 μmol/L of MG-132 for 24, 48, 72 and 96 h (P<0.01). The percentage of cells at G0/G1 phase was increased and that at S and G2/M was decreased (P<0.01). The rate of apoptotic cells treated with 5 μmol/L of MG-132 for 48 and 96 h was 31.7% and 66.4%, respectively. Agarose electrophoresis showed marked ladders. In addition, the positive signals of p27^kip1 were located in cytoplasm and nuclei in MG-132 group in contrast to cytoplasm staining in control group. CONCLUSION: MG-132 can obviously inhibit proliferation of EC9706 cells and induce apoptosis. The mechanisms include upregulation of p27^kip1 expression, G1 arrest and depression of telomerase activity. The results indicate that inhibiting UPP is a novel strategy for esophageal carcinoma therapy.展开更多
AIM: To explore the effects of mifepristone, a progesterone receptor (PR) antagonist, on the proliferation of human gastric adenocarcinoma cell line SGC-7 901 in vitro and the possible mechanisms involved.METHODS: In ...AIM: To explore the effects of mifepristone, a progesterone receptor (PR) antagonist, on the proliferation of human gastric adenocarcinoma cell line SGC-7 901 in vitro and the possible mechanisms involved.METHODS: In situ hybridization was used to detect the expression of PR mRNA in SGC-7 901 cells. After treatment with various concentrations of mifepristone (2.5, 5, 10,20μmol/L) at various time intervals, the ultrastructural changes, cell proliferation, cell-cycle phase distribution, and the expression of caspase-3 and Bcl-XL were analyzed using transmission electron microscopy (TEM), tetrazolium blue (MTT) assay, ^3H-TdR incorporation, flow cytometry, and reverse transcription-polymerase chain reaction (RT-PCR).RESULTS: Mifepristone markedly induced apoptosis and inhibited cell proliferation of PR- positive SGC-7 901 cells revealed by TEM, MTT assay and ^3H-TdR incorporation, in a dose- and time-dependent manner. The inhibitory rate was increased from 8.98% to 51.29%. Flow cytometric analysis showed mifepristone dose-dependently decreased cells in S and G2/M phases, increased cells in G0/G1 phase,reduced the proliferative index from 57.75% to 22.83%.In addition, mifepristone up-regulated the expression of caspase-3, and down- regulated the Bcl-XL expression,dose-dependently.CONCLUSION: Mifepristone effectively inhibited the proliferation of PR-positive human gastric adenocarcinoma cell line SGC-7 901 in vilrothrough multiple mechanisms, and may be a beneficial agent against human adenocarcinoma.展开更多
AIM: To investigate the expression of gonadotropin-releasing hormone (GnRH) receptor and the effects of GnRH analog(alarelin) on proliferation of cultured gastric smooth muscle cells (GSMC) of rats. METHODS: Immunohis...AIM: To investigate the expression of gonadotropin-releasing hormone (GnRH) receptor and the effects of GnRH analog(alarelin) on proliferation of cultured gastric smooth muscle cells (GSMC) of rats. METHODS: Immunohistochemical ABC methods and in situ hybridization methods were used to dectect protein and mRNA expression of GnRH receptor in GSMC, respectively. Techniques of cell culture, OD value of MTT test, measure of ^3H-TdR incorporation, average fluorescent values of proliferating cell nuclear antigen (PCNA) and flow cytometric DNA analysis were used in the experiment. RESULTS: The cultured GSMC of rats showed immunoreactivity for GnRH receptor; positive staining was located in cytoplasm. GnRH receptor mRNA hybridized signals were also detected in cytoplasm. When alarelin (10^-9, 10^-7, 10^-5 mol/L) was administered into the medium and incubated for 24 h, OD value of MTT, ^3H-TdR incorporation and average fluorescent values of PCNA all decreased significantly as compared with the control group (P<0.05). The maximum inhibitory effect on cell proliferation was achieved a concentration of 10s mol/L and it acted in a dose-dependent manner. Flow cytometric DNA analysis revealed that alarelin could significantly enhance ratio of G1 phase and decrease ratio of S phase of GSMC of rats (P<0.05).The maximum inhibitory effect on ratio of S phase was at the concentration of 10-s mol/L and also acted in a dose-dependent manner. CONCLUSION: Our data suggest that GnRH receptor can be expressed by GSMC of rats. GnRH analogue can directly inhibit proliferation and DNA synthesis of rat GSMC through GnRH receptors.展开更多
Explants of bitter melon can produce three types of callus: green, yellow green and fragile yellow callus. During the period of inducing callus, the explants are not sensitive to the kinds and proportions of phytohorm...Explants of bitter melon can produce three types of callus: green, yellow green and fragile yellow callus. During the period of inducing callus, the explants are not sensitive to the kinds and proportions of phytohormone. The rate of callus inductivity is about 90.0%. However, in the process of callus differentiating adventitious bud, the kind, proportion and quantity of phytohormone and the type of callus made different result. The adventitious buds were induced successfully on MS medium+6-BA (N6-benzyladenine) 4.0 mg l-1+KT(kinetin) 2.0 mg l-1) by yellow green callus. The frequency was about 66.7 %. Yellow callus did not differentiated adventitious bud. The frequency of green callus differentiation was very low (<15.0 %) even under the most suitable conditions. The MS + ZT (zeatin) 5.0 mgl-1 +KT 0.5 mgl-1 medium was suitable for the proliferation of bud and three weeks later, the coefficient of proliferation was about 5-6. The 1/2 MS + ZT 0.02 mgl-1 or 1/2 MS media were suitable for in vitro rooting of shoot, the shoot on them could produce 6-7 new roots in three weeks. After plantation test, the survival rate of tube plantlets was about 70% and their characteristics were the same as those from seed by field test.展开更多
Objective: To investigate the regulatory effect of curcumin on proliferation and apoptosis in human cervical carcinoma cell line HeLa in vitro. Methods: Human cervical carcinoma cell line Hela was cultured in vitro. H...Objective: To investigate the regulatory effect of curcumin on proliferation and apoptosis in human cervical carcinoma cell line HeLa in vitro. Methods: Human cervical carcinoma cell line Hela was cultured in vitro. HeLa cells were treated with 10(50 (mol/L curcumin for 24(72 h and the growth inhibition rates of HeLa cells were measured by MTT method. Cell apoptosis was inspected by electron microscopy. In addition, the expression of bcl-2, bcl-xl and caspase-3 protein in HeLa cell were observed by SP immunohistochemistry. Results: Curcumin inhibited the proliferation of HeLa cells on a dose-depending manner. Peak of subG1 appeared on DNA histogram in FCM. A portion of the cells presented the characteristic morphological changes of apoptosis under the electron microscope. The bcl-2, bcl-xl expression was decreased while Caspase-3 expression was increased. Conclusion: Curcumin could significantly inhibit the growth of HeLa cells; inducing apoptosis through up-regulating Caspase-3 and down-regulating expression of bcl-2 and bcl-xl was probably one of its molecular mechanisms.展开更多
Objective: To investigate the effects of insulin-like growth factor Ⅱ (IGF-Ⅱ) on promoting cell proliferation, regulating levels of cellular nitric oxide (NO) and mRNA transcriptions of inducible nitric oxide syntha...Objective: To investigate the effects of insulin-like growth factor Ⅱ (IGF-Ⅱ) on promoting cell proliferation, regulating levels of cellular nitric oxide (NO) and mRNA transcriptions of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) in mouse osteoblast-like cells. Methods: Mouse osteoblastic cell line MC3T3-E1 was selected as the effective cell of IGF-Ⅱ. After the cells were treated with IGF-Ⅱ at different concentrations for different time duration,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay was used to examine cell proliferation,and nitrate reductase method was applied to detect NO concentrations in cell culture supernatants and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was employed to determine transcription levels of cellular iNOS and eNOS mRNAs. Results: After the MC3T3-E 1 cells were treated with IGF-Ⅱ at concentration of 1 ng/ml for 72 h, 10 and 100 ng/ml for 24,48 and 72 h respectively, all the MTT values increased (P<0.05 or P<0.01) with obvious dosage-time dependent pattern. NO levels of the MC3T3-E1 cells treated with 100 ng/ml IGF-Ⅱ for 48 h, and with 1, 10 and 100 ng/ml IGF-Ⅱ for 72 h were remarkably lower than that of the normal control, respectively (P<0.05 or P<0.01). After the cells were treated with 100 ng/ml IGF-Ⅱ for 48 h cellular iNOS mRNA levels were significantly decreased (P<0.01). But the levels of eNOS mRNA in the cells treated with each of the used IGF-Ⅱ dosages for different time duration did not show any differences compared with the normal control (P>0.05).Conclusion: IGF-Ⅱ at different concentrations could promote proliferation of mouse MC3T3-E1 cell. This cell proliferation promotion was associated with the low NO levels maintained by IGF-Ⅱ. Higher concentration of IGF-Ⅱ could down-regulate iNOS gene expression at the level of transcription but not affect transcription of eNOS mRNA, which might be one of the mechanisms for IGF-Ⅱ maintenance of the low NO levels in MC3T3-E 1 cells.展开更多
基金Supported by the National Natural Science Foundation of China,No.39970637
文摘AIM: To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism.METHODS: MTT assay was applied in the detection of the inhibitory effects of genistein on cell proliferation. Flow cytometry was used to analyze the cell cycle distribution.Immunocytochemical technique and Western blotting were performed to detect the protein expression of cyclin D1,cyclin B1 and p21waf1/cip1.RESULTS: Genistein significantly inhibited the growth and proliferation of human gastric carcinoma cells (SGC-7901).Seven days after treatment with different concentrations of genistein (2.5, 5.0, 10.0, 20.0 μg/mL), the growth inhibitory rates were 11.2%, 28.8%, 55.3%, 84.7%respectively and cell cycles were arrested at the G(2)/Mphase. Genistein decreased cyclin D1 protein expression and enhanced cyclin B1 and p21waf/cip1 protein expression in a concentration-dependent manner.CONCLUSION: The growth and proliferation of SGC-7901 cells can be inhibited by genistein via blocking the cell cycle,with reduced expression of cyclin D1 and enhanced expression of cyclin B1 and p21waf/cip1 protein in the concentration range of 0-20 μg/mL.
基金Supported by the Grant for Nature and Science from Shanghai,No.03ZR 14097
文摘AIM: To explore the effects of endothelin-1(ET-1) on hepatic stellate cells (HSCs) DNA uptake, DNA synthesis,collagen synthesis and secretion, inward whole-cell calcium concentration ([Ca^2+]i) as well as the blocking effect of verapamil on ET-l-stimulated release of inward calcium(Ca2+) of HSC in vitro.METHODS: Rat hepatic stellate cells (HSCs) were isolated and cultivated. ^3H-TdR and ^3H-proline incorporation used for testing DNA uptake and synthesis, collagen synthesis and secretion of HSCs cultured in vitro;, Fluorescent calcium indicator Fura-2/AM was used to measure [Ca^2+]i inwardHSCs.RESULTS: ET-1 at the concentration of 5×10^-8 mol/L,caused significant increase both in HSC DNA synthesis (2 247+344 cpm, P<0.05) and DNA uptake (P<0.05) when compared with the control group. ET-1 could also increase collagen synthesis (P<0.05 vs control group) and collagen secretion (P<0.05 vscontrol group). Besides, inward HSC [Ca^2+]i reached a peak concentration (422±98 mol/L, P<0.001)at 2 min and then went down slowly to165+51 mol/L(P<0.01) at 25 min from resting state (39±4 mol/L)after treated with ET-1. Verapamil (5 mol/L) blocked ET-1-activated [Ca^2+li inward HSCs compared with control group(P<0.05). Fura-2/AM loaded HSC was suspended in no Ca^2+ buffer containing 1 mol/L EGTA, 5 rain later, 10^-8 mol/L of ET-1 was added, [Ca^2+]i inward HSCs rose from resting state to peak 399±123 mol/L, then began to come down by the time of 20 min. It could also raise [Ca^2+]i inward HSCs even without Ca^2+ in extracellular fluid, and had a remarkable dose-effect relationship(P<0.05). Meanwhile,verapamil could restrain the action of ET-1(P<0.05).CONCLUSION: Actions of ET-1 on collagen metabolism of HSCs may depend on the transportation of inward wholecell calcium.
基金Supported by the Natural Science Foundation of Zhejiang Province,No.398402
文摘AIM: Liver fibrosis is a common pathological process of chronic liver diseases. Activation of hepatic stellate cells(HSCs) is the key issue in the occurrence of liver fibrosis. In this study, we observed the inhibitory action of rat serum containing Biejiajian oral liquid (BOL), a decoction of turtle shell, on proliferation of rat HSCs, and to explore the antihepatofibrotic mechanisms of BOL.METHODS: A rat model of hepatic fibrosis was induced by subcutaneous injection of CC14. Serum containing low,medium and high dosages of BOL was prepared respectively.Normal and fibrotic HSCs were isolated and cultured. The effect of sera containing BOL on proliferation of HSCs was determined by 3H-TdR incorporation.RESULTS: The inhibitory rate of normal rat HSC proliferation caused by 100 mL/mL sera containing medium and high dosages of BOL showed a remarkable difference as compared with that caused by colchicine (medium dosage group:34.56±4.21% vs29.12±2.85%, P<0.01; high dosage group:37.82±1.32% vs29.12±2.85%, P<0.01). The inhibitory rate of fibrotic rat HSC proliferation caused by 100 mL/L serum containing medium and high dosages of BOL showed a remarkable difference as compared with that caused by colchicine (medium dosage group: 51.31_+3.14% vs 38.32_+2.65%,P<0.01; high dosage group: 60.15_+5.36% vs38.32_+2.65%,P<0.01). The inhibitory rate of normal rat HSC proliferation caused by 100 mL/L and 200 mL/L sera containing a medium dosage of BOL showed a significant difference as compared with that caused by 50 mL/L (100 mL/L group: 69.02±9.96%vs 50.82±9.28%, P<0.05; 200 mL/L group: 81.78±8.92%vs50.82±9.28%, P<0.01). The inhibitory rate of fibrotic rat HSC proliferation caused by 100 mL/L and 200 mL/L sera containing a medium dosage of BOL showed a significant difference as compared with that caused by 50 mL/L (100 mL/L group:72.19±10.96% vs 61.38±7.16%, P<0.05; 200 mL/L group:87.16±8.54% vs 61.38±7.16%, P<0.01).CONCLUSION: Rat serum containing BOL can inhibit proliferation of rat HSCs, and the inhibition depends on the dosage and concentration of BOL. The inhibitory effect on HSC proliferation is one of the main anti-hepatofibroticmechanisms of BOL.
文摘AIM: To investigate the inhibitory effect of ubiquitin-proteasome pathway (UPP) on proliferation of esophageal carcinoma cells.METHODS: Esophageal carcinoma cell strain EC9706 was treated with MG-132 to inhibit its UPP specificity. Cell growth suppression was evaluated with 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. DNA synthesis was evaluated by ^3H-thymidine (^3H-TdR) incorporation. Morphologic changes of cells were observed under microscope. Activity of telomerase was examined by telomeric repeat amplification protocol (TRAP) of PCRELISA. Cell cycle and apoptosis were detected by flow cytometry (FCM). DNA fragment analysis was used to confirm the presence of apoptosis. Expression of p27^kip1 was detected by immunocytochemical technique. RESULTS: After exposed to MG-132, the growth and value of ^3H-TdR incorporation of EC9706 cells were obviously inhibited. Cells became round, small and exfoliative under microscope. TRAP PCR-ELISA showed that light absorption of cells gradually decreased after exposed to 5 μmol/L of MG-132 for 24, 48, 72 and 96 h (P<0.01). The percentage of cells at G0/G1 phase was increased and that at S and G2/M was decreased (P<0.01). The rate of apoptotic cells treated with 5 μmol/L of MG-132 for 48 and 96 h was 31.7% and 66.4%, respectively. Agarose electrophoresis showed marked ladders. In addition, the positive signals of p27^kip1 were located in cytoplasm and nuclei in MG-132 group in contrast to cytoplasm staining in control group. CONCLUSION: MG-132 can obviously inhibit proliferation of EC9706 cells and induce apoptosis. The mechanisms include upregulation of p27^kip1 expression, G1 arrest and depression of telomerase activity. The results indicate that inhibiting UPP is a novel strategy for esophageal carcinoma therapy.
基金Supported by the National Key Research Project Foundation of China,No.96-905-02-01,and the National Natural Science Foundation of China,No.39630340
文摘AIM: To explore the effects of mifepristone, a progesterone receptor (PR) antagonist, on the proliferation of human gastric adenocarcinoma cell line SGC-7 901 in vitro and the possible mechanisms involved.METHODS: In situ hybridization was used to detect the expression of PR mRNA in SGC-7 901 cells. After treatment with various concentrations of mifepristone (2.5, 5, 10,20μmol/L) at various time intervals, the ultrastructural changes, cell proliferation, cell-cycle phase distribution, and the expression of caspase-3 and Bcl-XL were analyzed using transmission electron microscopy (TEM), tetrazolium blue (MTT) assay, ^3H-TdR incorporation, flow cytometry, and reverse transcription-polymerase chain reaction (RT-PCR).RESULTS: Mifepristone markedly induced apoptosis and inhibited cell proliferation of PR- positive SGC-7 901 cells revealed by TEM, MTT assay and ^3H-TdR incorporation, in a dose- and time-dependent manner. The inhibitory rate was increased from 8.98% to 51.29%. Flow cytometric analysis showed mifepristone dose-dependently decreased cells in S and G2/M phases, increased cells in G0/G1 phase,reduced the proliferative index from 57.75% to 22.83%.In addition, mifepristone up-regulated the expression of caspase-3, and down- regulated the Bcl-XL expression,dose-dependently.CONCLUSION: Mifepristone effectively inhibited the proliferation of PR-positive human gastric adenocarcinoma cell line SGC-7 901 in vilrothrough multiple mechanisms, and may be a beneficial agent against human adenocarcinoma.
基金Supported by the Natural Science Foundation of China,No.39770388
文摘AIM: To investigate the expression of gonadotropin-releasing hormone (GnRH) receptor and the effects of GnRH analog(alarelin) on proliferation of cultured gastric smooth muscle cells (GSMC) of rats. METHODS: Immunohistochemical ABC methods and in situ hybridization methods were used to dectect protein and mRNA expression of GnRH receptor in GSMC, respectively. Techniques of cell culture, OD value of MTT test, measure of ^3H-TdR incorporation, average fluorescent values of proliferating cell nuclear antigen (PCNA) and flow cytometric DNA analysis were used in the experiment. RESULTS: The cultured GSMC of rats showed immunoreactivity for GnRH receptor; positive staining was located in cytoplasm. GnRH receptor mRNA hybridized signals were also detected in cytoplasm. When alarelin (10^-9, 10^-7, 10^-5 mol/L) was administered into the medium and incubated for 24 h, OD value of MTT, ^3H-TdR incorporation and average fluorescent values of PCNA all decreased significantly as compared with the control group (P<0.05). The maximum inhibitory effect on cell proliferation was achieved a concentration of 10s mol/L and it acted in a dose-dependent manner. Flow cytometric DNA analysis revealed that alarelin could significantly enhance ratio of G1 phase and decrease ratio of S phase of GSMC of rats (P<0.05).The maximum inhibitory effect on ratio of S phase was at the concentration of 10-s mol/L and also acted in a dose-dependent manner. CONCLUSION: Our data suggest that GnRH receptor can be expressed by GSMC of rats. GnRH analogue can directly inhibit proliferation and DNA synthesis of rat GSMC through GnRH receptors.
文摘Explants of bitter melon can produce three types of callus: green, yellow green and fragile yellow callus. During the period of inducing callus, the explants are not sensitive to the kinds and proportions of phytohormone. The rate of callus inductivity is about 90.0%. However, in the process of callus differentiating adventitious bud, the kind, proportion and quantity of phytohormone and the type of callus made different result. The adventitious buds were induced successfully on MS medium+6-BA (N6-benzyladenine) 4.0 mg l-1+KT(kinetin) 2.0 mg l-1) by yellow green callus. The frequency was about 66.7 %. Yellow callus did not differentiated adventitious bud. The frequency of green callus differentiation was very low (<15.0 %) even under the most suitable conditions. The MS + ZT (zeatin) 5.0 mgl-1 +KT 0.5 mgl-1 medium was suitable for the proliferation of bud and three weeks later, the coefficient of proliferation was about 5-6. The 1/2 MS + ZT 0.02 mgl-1 or 1/2 MS media were suitable for in vitro rooting of shoot, the shoot on them could produce 6-7 new roots in three weeks. After plantation test, the survival rate of tube plantlets was about 70% and their characteristics were the same as those from seed by field test.
文摘Objective: To investigate the regulatory effect of curcumin on proliferation and apoptosis in human cervical carcinoma cell line HeLa in vitro. Methods: Human cervical carcinoma cell line Hela was cultured in vitro. HeLa cells were treated with 10(50 (mol/L curcumin for 24(72 h and the growth inhibition rates of HeLa cells were measured by MTT method. Cell apoptosis was inspected by electron microscopy. In addition, the expression of bcl-2, bcl-xl and caspase-3 protein in HeLa cell were observed by SP immunohistochemistry. Results: Curcumin inhibited the proliferation of HeLa cells on a dose-depending manner. Peak of subG1 appeared on DNA histogram in FCM. A portion of the cells presented the characteristic morphological changes of apoptosis under the electron microscope. The bcl-2, bcl-xl expression was decreased while Caspase-3 expression was increased. Conclusion: Curcumin could significantly inhibit the growth of HeLa cells; inducing apoptosis through up-regulating Caspase-3 and down-regulating expression of bcl-2 and bcl-xl was probably one of its molecular mechanisms.
基金Project (No. 991103115) was supported by a grant from the Department of Zhejiang Science and Technology, China
文摘Objective: To investigate the effects of insulin-like growth factor Ⅱ (IGF-Ⅱ) on promoting cell proliferation, regulating levels of cellular nitric oxide (NO) and mRNA transcriptions of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) in mouse osteoblast-like cells. Methods: Mouse osteoblastic cell line MC3T3-E1 was selected as the effective cell of IGF-Ⅱ. After the cells were treated with IGF-Ⅱ at different concentrations for different time duration,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay was used to examine cell proliferation,and nitrate reductase method was applied to detect NO concentrations in cell culture supernatants and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was employed to determine transcription levels of cellular iNOS and eNOS mRNAs. Results: After the MC3T3-E 1 cells were treated with IGF-Ⅱ at concentration of 1 ng/ml for 72 h, 10 and 100 ng/ml for 24,48 and 72 h respectively, all the MTT values increased (P<0.05 or P<0.01) with obvious dosage-time dependent pattern. NO levels of the MC3T3-E1 cells treated with 100 ng/ml IGF-Ⅱ for 48 h, and with 1, 10 and 100 ng/ml IGF-Ⅱ for 72 h were remarkably lower than that of the normal control, respectively (P<0.05 or P<0.01). After the cells were treated with 100 ng/ml IGF-Ⅱ for 48 h cellular iNOS mRNA levels were significantly decreased (P<0.01). But the levels of eNOS mRNA in the cells treated with each of the used IGF-Ⅱ dosages for different time duration did not show any differences compared with the normal control (P>0.05).Conclusion: IGF-Ⅱ at different concentrations could promote proliferation of mouse MC3T3-E1 cell. This cell proliferation promotion was associated with the low NO levels maintained by IGF-Ⅱ. Higher concentration of IGF-Ⅱ could down-regulate iNOS gene expression at the level of transcription but not affect transcription of eNOS mRNA, which might be one of the mechanisms for IGF-Ⅱ maintenance of the low NO levels in MC3T3-E 1 cells.
