p75NTR promotes survival of breast cancer resistant cells by regulating Bcl-2/Bax and MAPK pathway.

In breast cancer, the neurotrophin receptor p75NTR is a critical factor that promotes resistance to the drug, however, its mechanism of action remains unclear. In our study, the 10 cases of positive expressions of p75NTR were detected in 86 cases of breast cancer tissues, accounting for 11.6% of cases detected. The immunohistochemistry detection of p75NTR was in the cytoplasm and cell membrane. The expression of p75NTR was significantly associated with histological grade (P<0.01), however, not with the menopause, tumor size and lymph node metastasis. Western blot result showed that p75NTR protein was induced by overexpression in the multidrug-resistant breast cancer cell lines. After transfection of pcDNA3.1-p75NTR, MDA-MB-231/ADR-p75NTR cell cycle was arrested in G0/G1 phase. However, the number of cells in G0/G1 phase increased and decreased in S phase cells (P<0.05). Additionally, apoptosis rate decreased (P<0.05). The p75NTR overexpression increased the expression of MDR related protein and activated MAPK signaling pathway. IJCEP