Autoantibodies Specific to ERα are Involved in Tamoxifen Resistance in Hormone Receptor Positive Breast Cancer.

ABSTRACT: Tamoxifen resistance is a major hurdle in the treatment of estrogen receptor (ER)-positive breast cancer. The mechanisms of tamoxifen resistance are not fully understood although several underlying molecular events have been suggested. Recently, we identified autoantibodies reacting with membrane-associated ERα (anti-ERα Abs) in sera of breast cancer patients, able to promote tumor growth. Here, we investigated whether anti-ERα Abs purified from sera of ER-positive breast cancer patients could contribute to tamoxifen resistance. Anti-ERα Abs inhibited tamoxifen-mediated effects on cell cycle and proliferation in MCF-7 cells. Moreover, anti-ERα Abs hampered the tamoxifen-mediated reduction of tumor growth in SCID mice xenografted with breast tumor. Notably, simvastatin-mediated disaggregati

SUBMITTER: Maselli A 

PROVIDER: S-EPMC6678306 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature