Conclusions
Our results demonstrate that MDR1 could increase cellular apoptosis by regulating the expression of GCS in breast cancer cells.
Methods
A plasmid with multidrug resistence 1(mdr1) cDNA was transfected into the sensitive breast cancer cell line MCF-7, while an RNA interference (RNAi) vector targeted mdr1 was transfected into the MDR cell line MCF-7/ADM. Then RT-PCR, Western blot, MTT, and flow cytometry were used to assess the expression and function of mdr1 and GCS. Result: The data displayed that up-regulation of mdr1 could increase the expression of GCS, while the RNAi-expression plasmids could decrease that. Meantime, the changes of ceramide are opposed to that of GCS and are the same to the alteration of apoptosis rate. Conclusions: Our