Over-expression of P-glycoprotein(P-gp),an ATP-dependent drug efflux pump,represents one of the major mechanisms that contribute to multidrug resistance(MDR) in cancer cells.This study examined the effects of troglita...Over-expression of P-glycoprotein(P-gp),an ATP-dependent drug efflux pump,represents one of the major mechanisms that contribute to multidrug resistance(MDR) in cancer cells.This study examined the effects of troglitazone,a ligand of peroxisome proliferator-activated receptor gamma(PPARγ),on P-gp-mediated MDR in SGC7901/VCR cells(a vincristine-resistant human gastric cancer cell line).The expression of P-gp was detected by RT-PCR and Western blotting,respectively.The SGC7901/VCR cells were treated with 0.1 mg/L vincristine(VCR) alone or in combination with 1,5,10 μmol/L troglitazone for 24 h.PPARγ was measured by electrophoretic mobility shift assay(EMSA).The intracellular concentration of Rhodamine123(Rh123,a fluorescent P-gp substrate) was assayed to evaluate the activity of P-gp.The cell cycle and apoptosis were measured by flow cytometry.The results showed that the P-gp was increasingly expressed in SGC7901,BGC823 and SGC7901/VCR cells in turn,suggesting that MDR in the SGC7901/VCR cells was mediated by the increased expression of P-gp.In the SGC7901/VCR cells,the expression level of total PPARγ was increased,however,the protein level and activity of PPARγ in the nuclei of cells decreased significantly.Troglitazone elevated the PPARγ activity in SGC7901/VCR cells in a dose-dependent manner.Troglitazone decreased the P-gp expression and markedly enhanced the accumulation of Rh123 in SGC7901/VCR cells in a dose-dependent manner.We also found that troglitazone significantly increased the percentage of SGC7901/VCR cells in the G2/M phase and decreased the cell percentage in G1 and S phase in a dose-dependent manner.Troglitazone significantly increased the apoptotic rate of SGC7901/VCR cells treated by VCR or ADR in a dose-dependent manner.It was concluded that P-gp-overexpressed SGC7901/VCR cells have minor endogenous PPARγ activity.Elevation of the PPARγ activity by troglitazone can reverse P-gp-mediated MDR via down-regulating the expression and activity of P-gp in SGC7901/VCR cells.It was suggested that troglitazone can dramatically enhance the sensitivity of P-gp-mediated MDR cancer cells to chemotherapeutic agents.展开更多
[Objectives]To observe the effect of drug-containing serum from different extracts of Phyllanthus reticulatus leaf on the proliferation of human gastric cancer SGC-7901 cells and the effect of in vivo on the life exte...[Objectives]To observe the effect of drug-containing serum from different extracts of Phyllanthus reticulatus leaf on the proliferation of human gastric cancer SGC-7901 cells and the effect of in vivo on the life extension rate of mice with H22 ascites tumor,and to investigate the effects of chemical components such as Corilagin,ethyl gallate,ethyl brevifolincarboxylate,and gallic acid on the proliferation of human gastric cancer SGC-7901 cells.[Methods]MTT method was used to observe the inhibitory effect of drug-containing serum of different extracts of P.reticulatus leaf on human gastric cancer SGC-7901 cells in vitro to determine its active site.The active site was used as the research object to establish a Kunming mouse ascites tumor model,to investigate the effect on the life extension rate of mice with H22 ascites tumor,to further separate the monomer components from the effective fraction and investigate its effect on human gastric cancer SGC-7901 cells.[Results]Compared with the 10%blank serum control group,10%drug-containing serum of ethyl acetate and n-butanol in P.reticulatus leaf had significant inhibitory effect on the proliferation of human gastric cancer SGC-7901 cells,and the inhibition rate was 34.99%and 28.68%,respectively(P<0.05).Compared with the blank group,the survival time of the high dose group of ethyl acetate in P.reticulatus leaf was significant(P<0.05).Gallic acid,Corilagin,and Brevifolincarboxylic acid ethyl ester had a significant inhibitory effect on the proliferation of human gastric cancer SGC-7901 cells,with IC 50 of 26.52,70.45,and 158.86μg/mL,respectively.Ethyl gallate had no inhibitory effect on the proliferation of human gastric cancer SGC-7901 cells,and its IC 50 was 251.96μg/mL.[Conclusions]The drug-containing serum of ethyl acetate and n-butanol extract of P.reticulatus can inhibit the proliferation of human gastric cancer SGC-7901 cells.Ethyl acetate of P.reticulatus leaves can increase the life extension rate of mice with H22 ascites tumor.Gallic acid,Corilagin,and Brevifolincarboxylic acid ethyl ester isolated from its active site are the material basis for inhibiting the proliferation of human gastric cancer SGC-7901 cells.展开更多
OBJECTIVE To investigate whether nimesulide can suppress tumor growth and induce apoptosis in SGC-7901 gastric cancer cells and to explore the molecular mechanism involved. METHODS SGC-7901 cells were cultured in RPMI...OBJECTIVE To investigate whether nimesulide can suppress tumor growth and induce apoptosis in SGC-7901 gastric cancer cells and to explore the molecular mechanism involved. METHODS SGC-7901 cells were cultured in RPMI 1640 medium con- taining different concentrations of nimesulide (0,12.5, 50, 100, 200, 400 Mmol/L). The MTT assay, morphological observation, electron microscopy (EM), immunohistochemical analysis and Western blot analysis were em- ployed to investigate the effects of nimesulide on the SGC-7901 cells and to explore possible related molecular mechanisms. RESULTS Nimesulide inhibited the growth of SGC-7901 cells and elicit- ed typical apoptotic morphologic changes. Nimesulide also decreased NF-κB and Bcl-2 expression, but increased the level of the Bax protein. The positive rate of Bcl -2 protein expression at 0, 50, 100 and 200 μmol/L of nimesulide was 58.3±14.0%, 50.2±9.9%, 32.8±5.0% and 22.7± 5.5% respectively based on immunohistochemical staining. The positive rate of Bax protein expression was 22.0 ±5.7%, 29.2 ±6.5%, 42.7 ±5.9% and 74.5±9.1% and the NF-κB expression was 74.2+10.9%, 61.8±7.6%, 36.7 ±10.9% and 17.5 ±12.3%, Significant differences were found be- tween 0 μmol/L and 100 μmoI/L and 200 μmol/L. Western blot analysis al- so showed that the expression of NF-κB was decreased. CONCLUSION Nimesulide suppresses tumor growth and induces apop- tosis by inhibiting NF-κB expression, which may be related to the over- expression of Bax relative to Bcl-2 expression.展开更多
Objective: To research the inhibitory effect on SGC-7901 cells of α-pinene, and the related mechanism of α-pinene. Methods: Used the MTT method to detect inhibition rate and western blotting to detect the influence ...Objective: To research the inhibitory effect on SGC-7901 cells of α-pinene, and the related mechanism of α-pinene. Methods: Used the MTT method to detect inhibition rate and western blotting to detect the influence on expression of ATM, Phos-S1981ATM, H2AX, γH2AX, CHK2 and p-CHK2, p53 and phos-p53 cell cycle related protein in SGC-7901 cells. Results: The research found α-pinene could inhibit the proliferation of SGC-7901 cells observably in vitro, and the inhibition rate assumes the dependence on concentration;and western blotting results showed that, α-pinene could activate phospho-ATM, increase the amount of γH2AX (p p < 0.05);increase the expression of p-CHK2, p53 and phos-p53 (p p p < 0.05);But there is no significant effect on expression of CHK2 (p > 0.05). Conclusions: α-pinene could inhibit the proliferation of SGC-7901 cells, and by inducing ATM (Ataxia Telangiectasia-Mutated) kinase signal pathway in DNA damage response, activating cell cycle checkpoint, making the cell cycle arrest then exerts its anti-tumor effects.展开更多
基金supported by grants from Natural Sciences Foundation of Hubei Province (No.2007ABA065)Science and Technology Key Project of Health Bureau of Hubei Province (No.JX1B006)
文摘Over-expression of P-glycoprotein(P-gp),an ATP-dependent drug efflux pump,represents one of the major mechanisms that contribute to multidrug resistance(MDR) in cancer cells.This study examined the effects of troglitazone,a ligand of peroxisome proliferator-activated receptor gamma(PPARγ),on P-gp-mediated MDR in SGC7901/VCR cells(a vincristine-resistant human gastric cancer cell line).The expression of P-gp was detected by RT-PCR and Western blotting,respectively.The SGC7901/VCR cells were treated with 0.1 mg/L vincristine(VCR) alone or in combination with 1,5,10 μmol/L troglitazone for 24 h.PPARγ was measured by electrophoretic mobility shift assay(EMSA).The intracellular concentration of Rhodamine123(Rh123,a fluorescent P-gp substrate) was assayed to evaluate the activity of P-gp.The cell cycle and apoptosis were measured by flow cytometry.The results showed that the P-gp was increasingly expressed in SGC7901,BGC823 and SGC7901/VCR cells in turn,suggesting that MDR in the SGC7901/VCR cells was mediated by the increased expression of P-gp.In the SGC7901/VCR cells,the expression level of total PPARγ was increased,however,the protein level and activity of PPARγ in the nuclei of cells decreased significantly.Troglitazone elevated the PPARγ activity in SGC7901/VCR cells in a dose-dependent manner.Troglitazone decreased the P-gp expression and markedly enhanced the accumulation of Rh123 in SGC7901/VCR cells in a dose-dependent manner.We also found that troglitazone significantly increased the percentage of SGC7901/VCR cells in the G2/M phase and decreased the cell percentage in G1 and S phase in a dose-dependent manner.Troglitazone significantly increased the apoptotic rate of SGC7901/VCR cells treated by VCR or ADR in a dose-dependent manner.It was concluded that P-gp-overexpressed SGC7901/VCR cells have minor endogenous PPARγ activity.Elevation of the PPARγ activity by troglitazone can reverse P-gp-mediated MDR via down-regulating the expression and activity of P-gp in SGC7901/VCR cells.It was suggested that troglitazone can dramatically enhance the sensitivity of P-gp-mediated MDR cancer cells to chemotherapeutic agents.
基金Supported by Natural Science Research Project of Guangxi University of Chinese Medicine in 2015"Study on Anti-tumor Effect of Phyllanthus reticulatus Leaf Extract"(p15028)Independent Research Program of Guangxi Key Laboratory of Traditional Chinese Medicine Pharmacology in 2015"Study on Phyllanthus reticulatus Leaf 7404 Nude Mice Xenografts"+1 种基金Young Teachers Enhancement Project of Guangxi Department of Education in 2018"Study on the Mechanism of Zhuang Medicine Phyllanthus reticulatus Leaf against Liver Cancer"(2018KY0300)2019-2021 Guangxi First-class Discipline Construction Open Project Fund for Young Scholars of Guangxi University of Chinese Medicine"Anti-hepatocarcinoma Mechanism of Autophagy Induced by Ethyl Acetate in Phyllanthus reticulatus Leaf Based on PI3K/AKT and STAT3/m TOR Signaling Pathway"(2019XK089)
文摘[Objectives]To observe the effect of drug-containing serum from different extracts of Phyllanthus reticulatus leaf on the proliferation of human gastric cancer SGC-7901 cells and the effect of in vivo on the life extension rate of mice with H22 ascites tumor,and to investigate the effects of chemical components such as Corilagin,ethyl gallate,ethyl brevifolincarboxylate,and gallic acid on the proliferation of human gastric cancer SGC-7901 cells.[Methods]MTT method was used to observe the inhibitory effect of drug-containing serum of different extracts of P.reticulatus leaf on human gastric cancer SGC-7901 cells in vitro to determine its active site.The active site was used as the research object to establish a Kunming mouse ascites tumor model,to investigate the effect on the life extension rate of mice with H22 ascites tumor,to further separate the monomer components from the effective fraction and investigate its effect on human gastric cancer SGC-7901 cells.[Results]Compared with the 10%blank serum control group,10%drug-containing serum of ethyl acetate and n-butanol in P.reticulatus leaf had significant inhibitory effect on the proliferation of human gastric cancer SGC-7901 cells,and the inhibition rate was 34.99%and 28.68%,respectively(P<0.05).Compared with the blank group,the survival time of the high dose group of ethyl acetate in P.reticulatus leaf was significant(P<0.05).Gallic acid,Corilagin,and Brevifolincarboxylic acid ethyl ester had a significant inhibitory effect on the proliferation of human gastric cancer SGC-7901 cells,with IC 50 of 26.52,70.45,and 158.86μg/mL,respectively.Ethyl gallate had no inhibitory effect on the proliferation of human gastric cancer SGC-7901 cells,and its IC 50 was 251.96μg/mL.[Conclusions]The drug-containing serum of ethyl acetate and n-butanol extract of P.reticulatus can inhibit the proliferation of human gastric cancer SGC-7901 cells.Ethyl acetate of P.reticulatus leaves can increase the life extension rate of mice with H22 ascites tumor.Gallic acid,Corilagin,and Brevifolincarboxylic acid ethyl ester isolated from its active site are the material basis for inhibiting the proliferation of human gastric cancer SGC-7901 cells.
基金This work was supported by the grant form the Natural Science Foundation of the Education Department of Jiangsu Province of China (No. 05KJD320234 and 01KJB320011).
文摘OBJECTIVE To investigate whether nimesulide can suppress tumor growth and induce apoptosis in SGC-7901 gastric cancer cells and to explore the molecular mechanism involved. METHODS SGC-7901 cells were cultured in RPMI 1640 medium con- taining different concentrations of nimesulide (0,12.5, 50, 100, 200, 400 Mmol/L). The MTT assay, morphological observation, electron microscopy (EM), immunohistochemical analysis and Western blot analysis were em- ployed to investigate the effects of nimesulide on the SGC-7901 cells and to explore possible related molecular mechanisms. RESULTS Nimesulide inhibited the growth of SGC-7901 cells and elicit- ed typical apoptotic morphologic changes. Nimesulide also decreased NF-κB and Bcl-2 expression, but increased the level of the Bax protein. The positive rate of Bcl -2 protein expression at 0, 50, 100 and 200 μmol/L of nimesulide was 58.3±14.0%, 50.2±9.9%, 32.8±5.0% and 22.7± 5.5% respectively based on immunohistochemical staining. The positive rate of Bax protein expression was 22.0 ±5.7%, 29.2 ±6.5%, 42.7 ±5.9% and 74.5±9.1% and the NF-κB expression was 74.2+10.9%, 61.8±7.6%, 36.7 ±10.9% and 17.5 ±12.3%, Significant differences were found be- tween 0 μmol/L and 100 μmoI/L and 200 μmol/L. Western blot analysis al- so showed that the expression of NF-κB was decreased. CONCLUSION Nimesulide suppresses tumor growth and induces apop- tosis by inhibiting NF-κB expression, which may be related to the over- expression of Bax relative to Bcl-2 expression.
文摘Objective: To research the inhibitory effect on SGC-7901 cells of α-pinene, and the related mechanism of α-pinene. Methods: Used the MTT method to detect inhibition rate and western blotting to detect the influence on expression of ATM, Phos-S1981ATM, H2AX, γH2AX, CHK2 and p-CHK2, p53 and phos-p53 cell cycle related protein in SGC-7901 cells. Results: The research found α-pinene could inhibit the proliferation of SGC-7901 cells observably in vitro, and the inhibition rate assumes the dependence on concentration;and western blotting results showed that, α-pinene could activate phospho-ATM, increase the amount of γH2AX (p p < 0.05);increase the expression of p-CHK2, p53 and phos-p53 (p p p < 0.05);But there is no significant effect on expression of CHK2 (p > 0.05). Conclusions: α-pinene could inhibit the proliferation of SGC-7901 cells, and by inducing ATM (Ataxia Telangiectasia-Mutated) kinase signal pathway in DNA damage response, activating cell cycle checkpoint, making the cell cycle arrest then exerts its anti-tumor effects.