MCM3 upregulation confers endocrine resistance in breast cancer and is a predictive marker of diminished tamoxifen benefit.

ABSTRACT: Resistance to endocrine therapy in estrogen receptor-positive (ER⁺) breast cancer is a major clinical problem with poorly understood mechanisms. There is an unmet need for prognostic and predictive biomarkers to allow appropriate therapeutic targeting. We evaluated the mechanism by which minichromosome maintenance protein 3 (MCM3) influences endocrine resistance and its predictive/prognostic potential in ER⁺ breast cancer. We discovered that ER⁺ breast cancer cells survive tamoxifen and letrozole treatments through upregulation of minichromosome maintenance proteins (MCMs), including MCM3, which are key molecules in the cell cycle and DNA replication. Lowering MCM3 expression in endocrine-resistant cells restored drug sensitivity and altered phosphorylation

SUBMITTER: Lokkegaard S 

PROVIDER: S-EPMC7782683 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature