[Effects of Ad-p53 plus fulvestrant on induced apoptosis in MCF-7 breast cancer cells].

Objective: To explore the apoptosis-inducing effect of Ad-p53 plus fulvestrant in MCF-7 breast cancer cells.

Methods: ER-positive MCF-7 breast cancer cells were used. MCF-7 cells were established with control, fulvestrant alone, Ad-p53 alone and Ad-p53 plus fulvestrant. The morphological changes of MCF-7 after drug combination were observed by inverted microscopy. Methyltetrazolium salt (MTS) assay was used to determine the proliferation of MCF-7 cells. The protein expressions of p53 and ER were examined by Western blot. Flow cytometry was used to detect apoptosis.

Results: Significant inhibition of cell growth was observed by inverted microscopy. Flow cytometry revealed that the apoptosis rate of using fulvestrant alone or Ad-p53 alone was (13.3 ± 1.2) % and (14.5 ± 2.9) %. The apoptosis rate of combined group was (38.1 ± 5.9)% and it was higher than Ad-p53 or fulvestrant alone (P = 0.001, P = 0.001). MTS assay indicated that, after treating for 24, 48, 72, 96 h by Ad-p53 alone or fulvestrant alone, the inhibition of cell proliferation rate was (8.21 ± 0.54)%, (28.50 ± 1.42)%, (50.14 ± 0.78)%, (58.25 ± 2.92)% and (9.73 ± 1.68)%, (25.26 ± 0.82)%, (35.25 ± 3.94)% and (46.37 ± 2.56)% respectively. Simultaneously, the inhibition of cell proliferation rate of combined group was (12.42 ± 1.76)%, (35.20 ± 0.58)%, (62.08 ± 2.56)% and (75.43 ± 3.56)%. It further confirmed the increase of cell proliferation inhibition rate after drug combination (P < 0.05). Western blot showed that the p53 protein expression level increased obviously with Ad-p53 in MCF-7cells. Ad-p53 increased the level of ER expression while drug combination reduced the level of ER expression.

Conclusions: Ad-p53 plus fulvestrant can significantly inhibit cell growth and induce cell apoptosis. And there is probably some synergistic effects between both.