Effect of tamoxifen on early gene expression in T47D cells

Tamoxifen is the treatment of choice in estrogen receptor alpha breast cancer patients. However, ~50% of ER-positive tumors exhibit intrinsic or rapidly acquire resistance to endocrine treatment, requiring chemotherapy. t has been difficult to predict de novo resistance to endocrine therapy and/or assess the likelihood of early relapse, while no concrete mechanism regulating the acquisition and the maintenance of endocrine resistance has been identified. We have performed a whole transcriptome analysis of an ER-positive (T47D) and a triple-negative (MDA-MBA-231) breast cancer cell line exposed to tamoxifen for a short time frame (hours) in order to study resistance mechanisms that are initiated early after initiation of tamoxifen treatment.

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