[Anti-apoptotic mechanism for p21(waf1) in human basal like breast cancer cell line HCC1937].

Objective To explore the anti-apoptotic mechanism of p21waf1in human basal like breast cancer cell line HCC1937. Methods There were 3 groups, i.e.experimental group HCC1937 with lentivirus-p21waf1-shRNA-RFP, control group 1 HCC1937 without lentivirus and control group 2 HCC1937 with lentivirus-RFP.The p21waf1and bim mRNA and protein expressions were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot respectively.And apoptosis of HCC1937 in different groups was assayed by terminal deoxynucleotidyl transferase mediated C-d UTP nick end labeling (TUNEL). Results After interference with letivirus-p21waf1-sh RNA-RFP, p21waf1mRNA and protein expressions declined significantly in the experimental group versus the control groups (experiment group:0.260±0.004, 0.293±0.006, control group 1:0.879±0.028, 0.483±0.071, control group 2: 0.870±0.025, 0.469±0.047, all P<0.01).The bim mRNA and protein expressions increased.And there was significant difference between the experiment and control groups (experiment group: 0.420±0.013, 0.355±0.007, control group 1: 0.258±0.005, 0.142±0.012, control group 2: 0.259±0.002, 0.147±0.013, all P<0.001); apoptotic index increased (experiment group:0.279±0.012, control group 1:0.145±0.008, control group 2: 0.148±0.012, both P<0.001). Conclusion In human basal-like breast cancer cell line HCC1937, p21waf1exerts anti-apoptotic activity by inhibiting the expression of bim, a mediator of mitochondrial apoptosis. Key words: Breast neoplasms; P21; Bim; Apoptosis