Triple Negative Breast Cancer Cell Lines with TP53 Mutations are Able to Undergo Cell Death

Triple-negative breast cancer (TNBC) is a complex disease that lacks the expression of the estrogen, progesterone, and HER2 receptors. Over 80 % of TNBC cells have a mutated p53 tumor suppressor gene. The p53 pathway is responsible for a cells arrest or death response to stress. Here we show that the TNBC cell lines HCC1806 and HCC70 expresses the p53 protein and its downstream targets p21 and Puma. This study also revealed that the native forms of the p53 protein were not detected by immunofluorescence assays. Here we analyzed the cell death responses in triple-negative breast cancer cell lines HCC70 and HCC1806. We exposed the TNBC cell lines HCC70 and HCC1806, and a normal breast cell line AG11132 to the chemotherapeutics staurosporine, Actinomycin D, and doxorubicin for 24 hrss. We observed the physical characteristics of apoptosis in both HCC70 and HCC1806. We also performed Western blot analysis to reveal that Parp was cleaved in the TNBC cell lines. In conclusion, cell death responses and apoptosis occurred in the TNBC cell lines HCC70 and HCC1806 even though they have mutated p53 genes. Therefore, more experiments need to be conducted to determine whether apoptosis occurs in a p53-dependent or independent manner.