Mechanisms of Gefitinib-mediated reversal of tamoxifen resistance in MCF-7 breast cancer cells by inducing ERα re-expression.

ABSTRACT: Estrogen receptor (ER)-positive breast cancer patients may turn ER-negative and develop acquired drug resistance, which compromises the efficacy of endocrine therapy. By investigating the phenomenon that gefitinib can re-sensitise tamoxifen (TAM)-resistant MCF-7 breast cancer cells (MCF-7/TAM) to TAM, the present study verified that gefitinib could reverse the acquired drug resistance in endocrine therapy and further explored the underlying mechanism.ERα-negative MCF-7/TAM cells were established. Upon treating the cells with gefitinib, the mRNA and protein levels of ERα and ERβ, as well as the expression of molecules involved in the MAPK pathway, were examined using the RT-PCR and immunocytochemistry. The RT-PCR results showed that the mRNA levels of ERα and ERβ in MCF-7/TAM cells were up-

SUBMITTER: Zhang X 

PROVIDER: S-EPMC4314651 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature