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

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

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.

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.

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