Objective To study the effect of genistein (Gen) in combination with 5-fluorouracil (5-FU) on human gastric carcinoma cells in vitro. Methods Human gastric carcinoma cell line SGC-7901 was t reated with Gen and 5-FU alone or in combination for 24 , 48 and 72 hours , respectively. MTT assay was used to investigate the inhibitory effect of Gen and 5-FU on SGC-7901 cells. Transmission electron microscopy was used to observe the ultramicrost ructure changes of cancer cells and the flow cytometry was used to detect the distribution of cell cycle. Results Gen and 5-FU alone or in combination inhibited the proliferation of SGC-7901 cells significantly in both time-dependent and dose-dependent manner. The combination of Gen with 5-FU had synergistic effect on the growth of SGC-7901 cell line when the inhibition ratio was 20 % to 80 %. When SGC-7901 cells exposed to 18. 8μmol/ L Gen , 8. 84μmol/ L 52FU , and 3. 06μmol/ L Gen combined with 7. 96μmol/ L 5-FU for 72 hours , 62. 97 % , 63. 76 % and 67. 46 % SGC-7901 cells were arrested in G2 / M , S and G0 / G1 phrase , respectively. Gen and 5-FU could both induce apoptosis and arrest cell cycle of SGC-7901 cells. Conclusion Combination therapy of Gen with 5-FU may take synergistic inhibitory effect on the proliferation of gastric cancer cells by resting cell cycle and inducing cell apoptosis at a certain range of concent ration.
Objective To investigate the effects of genistein with different concentration on proliferation and apoptosis of cultured human retinal pigment epithelial (RPE) cells in vitro. Methods The effect of genistein with the concentration of 5，10，25，50，75，and 100 mg·L-1on the proliferation of cultured RPE was examined by tetrazolium salt (MTT) assay and AgNORs staining. The cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL) methods, in the mean time, the morphologic changes of cell apoptosis were observed by light microscopy and transmission electronic microscopy, the results of which were compared with the normal RPE cells. Results Genistein with the concentration of 25, 50, 75, and 100 mg·L-1had a dose-dependent and time-dependent antiproliferative effects on RPE cells with the inhibitory rate of 12.0%-64.6% (P＜0.05). The results of AgNORs staining showed that the number of AgNORs in the nucleolus decreased when treated by genistein. In TUNEL staining, the median of percent of apoptotic RPE cells was 7.6%, 9.8%, 13.7% when treated with 50 mg·L-1genistein, 10.3%, 16.4%, 23.4% when treated with 75 mg·L-1genistein, and 15.4%, 21.2%, 35.8% when treated with 100 m g·L-1genistein respectively for 24, 48, and 72 hours. After the treatme nt with 50 mg·L-1genistein for 48 hours, the apoptosis in the nucleolus of RPE cells was found. Conclusions Genistein with different concentrations has a dose-dependent and time-dependent antiproliferative effect on RPE cells. Genistein can induce the apoptosis of RPE cells when it reaches a certain extent of concentration. (Chin J Ocul Fundus Dis，2004，20：241-244)
【 Abstract 】 Objective To probe into the role of inositol 1, 4, 5-trisphosphate (IP3) and bax gene expression in apoptosis of HepG2 cells induced by genistein (Gen). Methods HepG2 cells were treated with different concentrations including 20, 40, 60 and 80 μ mol/L Gen as HepG2 cells cultured with 0 μmol/L Gen for 72 h was control; HepG2 cells were treated with 60 μmol/L Gen for 6, 12, 24, 48 and 72 h as HepG2 cells treated with 60 μmol/L Gen for 0 h was control. IP3 content, bax mRNA expression and apoptosis rate were assayed by IP3- ［ 3H ］ Birtrak assay, RT-PCR and flow cytometry, respectively. ResultsHepG2 cells incubated with each concentration of Gen for 72 h ， IP3 content was lower than that of control 〔 (17.7 ± 1.3), (11.2 ± 0.9), (4.9 ± 0.5), (4.8 ± 0.3) pmol/106 cells vs (29.4 ± 0.5) pmol/106 cells 〕 , P ＜ 0.01 ； bax mRNA expression (RI which was the gray degree multiply area of bax/the gray degree multiply area of β -actin) was higher than that of control (0.26 ± 0.02, 0.33 ± 0.05, 0.35 ± 0.06, 0.38 ± 0.05 vs 0.09 ± 0.01), P ＜ 0.01 ； The apoptosis rate was higher than that of control 〔 (10.1 ± 0.9)%, (18.7 ± 1.6)%, (28.7 ± 2.5)%, (27.9 ± 2.0)% vs (2.6 ± 0.1)% 〕 , P ＜ 0.01. HepG2 cells were incubated with 60 μ mol/L Gen for 6, 12, 24, 48 and 72 h ， IP3 content was lower than that of control 〔 (22.6 ± 0.9), (12.0 ± 1.4), (7.5 ± 0.8), (5.6 ± 0.5), (4.3 ± 0.6) pmol/106 cells vs (29.2 ± 0.6) pmol/106 cells 〕 , P ＜ 0.01 ； bax mRNA expression was higher than that of control incubated with 60 μ mol/L Gen for above 12 h (0.25 ± 0.06, 0.29 ± 0.02, 0.30 ± 0.02, 0.35 ± 0.04 vs 0.09 ± 0.01), P ＜ 0.01 ； The apoptosis rate in groups incubated with 60 μ mol/L Gen for 24, 48 and 72 h was significantly higher than that in control 〔 (7.4 ± 0.5)%, (20.5 ± 2.0)%, (30.7 ± 1.6)% vs (2.6 ± 0.1)% 〕 , P ＜ 0.01. ConclusionGen induces apoptosis of HepG2 cells by reducing IP3 production and increasing bax gene expression.