ABSTRACT
The aim of the present study was to investigate the effects of epigallocatechin-3-gallate (EGCG) on the apoptosis of the human MCF-7 cancer cell line and the underlying mechanism. MCF-7 cells were divided into the control group and EGCG groups. The proliferation of MCF-7 cells in the two groups was determined using MTT and apoptosis was examined using flow cytometry. Western blot analysis and qRT-PCR were used to analyze P53 and Bcl-2 expression levels. The silencing effect of specific siRNA was evaluated using RT-PCR and western blot analysis. P53 and Bcl-2 expression levels were determined using western blot analysis in the si-P53, EGCG and EGCG-combined si-P53 groups. EGCG inhibited the proliferation of MCF-7 cells in a concentration-dependent manner and IC50 was 37.681 mol/l. The apoptotic rates were 1.37 and 5.83% (t=8.9, p=0.0124) in the blank control and treatment groups after treatment with 30 µmol/l EGCG. The RT-qPCR and western blot results demonstrated that the effect of siRNA interference was evident. The expression of P53 in the EGCG-combined si-P53 group was higher than that of the si-P53 group, but lower than the EGCG group. The Bcl-2 expression level in the EGCG-combined si-P53 group was lower than that of the si-P53 group and higher than that of the EGCG group. In conclusion, EGCG suppressed the proliferation of human MCF-7 breast cancer cells and promoted apoptosis. In addition, the underlying mechanism may be related to the P53/Bcl-2 signaling pathway.
ABSTRACT
OBJECTIVE: To determine the expressions of ryanodine receptor type 1 (RyR1) and Cav1.3 L-type calcium channel (Cav1.3) in the vaginal smooth muscle cells of castrated rats and investigate the correlation of RyR1 and Cav1.3 with estrogen in female sexual dysfunction. METHODS: Forty female SD rats of 8 weeks were randomly divided into Groups A (2-week sham operation), B (4-week sham operation), C (2-week castration) and D (4-week castration). Two and 4 weeks after surgery, the serum estradiol level was determined with the automated immunochemiluminescence system and the expressions of RyR1 and Cav1.3 in the vaginal smooth muscle were detected by immunohistochemistry and RT-PCR. Gray scale ratio was used to represent the mRNA expression levels of RyR1 and Car1.3, and the optical density value to denote their protein expression levels. RESULTS: Serum estradiol was significantly decreased in Group C ([0.210 +/- 0.026] nmol/L) as compared with A ([0.505 +/- 0.053] nmol/L) (P < 0.01), and so was it in Group D ([0.130 +/- 0.031] nmol/L) in comparison with B ([0.476 +/- 0.058] nmol/L) (P < 0.01). RyR1 and Cav1.3 were expressed in all groups. The mRNA expressions of RyR1 and Cav1.3 were significantly reduced in Group C (0. 680 +/- 0.073 and 0.580 +/- 0.043) as compared with A (0.950 +/- 0.064 and 0.870 +/- 0.019) (P < 0.01), as well as in Group D (0.220 +/- 0.032 and 0.190 +/- 0.020) in comparison with B (0.890 +/- 0.072 and 0.820 +/- 0.021) (P < 0.01). The protein expressions of RyR1 and Cav1.3 were significantly down-regulated in Group C (96.67 +/- 7.75 and 87.97 +/- 6.96) as compared with A (123.69 +/- 10.66 and 106.46 +/- 8.04) (P < 0.01), and so were they in D (86.45 +/- 8.16 and 69.43 +/- 8.30) in comparison with B (109.31 +/- 9.87 and 97.38 +/- 7.56) (P < 0.01). CONCLUSION: Both RyR1 and Cav1.3 were expressed in the vaginal smooth muscle cells of the rats, and estrogen might be involved in the regulation of female sexual reaction by acting on the expressions of RyR1 and Cav1.3.
