Inhibitory effects of tamoxifen and tanshinone, alone or in combination, on the proliferation of breast cancer cells via activation of p38 MAPK signalling pathway

Purpose: To investigate the effects of tamoxifen and tanshinone administered individually or in combination, on proliferation breast cancer (BC) cells, underlying mechanism(s) action.
 Methods: Human cell lines (SNU-306, SNU-334 SNU-1528), normal primary mammary epithelial line (HMEC) were cultured at 37 °C Dulbecco's modified Eagle's medium (DMEM) supplemented with 5 % fetal bovine serum (FBS), l glutamine (2 mM), penicillin (100 U/ml) streptomycin μg/ml) a humidified incubator containing CO2. Cell was determined using MTT assay, while real-time quantitative polymerase chain reaction (qRT-PCR) used to determine expressions apoptosis-related genes. The p38 mitogenactivated protein kinases (p38 MAPK) by Western blotting.
 Results: There only few viable cells tamoxifen- tanshinone-treated wells, viability concentration-dependently reduced. Treatment SNU-306 (30 µM) (20 alone significantly reduced expression Wip1 after 72 h incubation, level treated combination tanshinones, relative those (p < 0.05). extent apoptosis higher than control Expressions Bax, caspase 3 p53 MAPK alone, treatment, 0.05).
 Conclusion: Tamoxifen promote BC via mechanisms involving up-regulation phosphorylation MAPK.