MedicalResearch.com Interview responses from: First author Gokul Das, PhD, Professor of Oncology and Co-Director of the Breast Translational Group, Department of Pharmacology & Therapeutics, Roswell Park Comprehensive Cancer Center Chetan Oturkar, PhD, Research Assistant Professor in the Department of Pharmacology & Therapeutics, Roswell Park Comprehensive Cancer Center, first author on the study MedicalResearch.com: What is the background for this study?  Dr. Gokul Das: Triple-negative breast cancer (TNBC) is a very aggressive subtype of breast cancer for which effective targeted therapies are not available, and which rapidly becomes resistant to chemotherapy. TNBC tumors are negative for estrogen receptor α (ERα), progesterone receptor (PR), and HER-2/neu receptor. Endocrine therapy or HER2-targeted therapies are not effective against TNBC. Currently available options including immunotherapy benefit only some patients. They are cost-prohibitive and have severe adverse effects. Therefore, there is an unmet need for rationally designed therapies for TNBC. Although ERα is absent in TNBC, majority of these tumors express estrogen receptor beta (ERβ), a structurally related but functionally distinct isoform of the estrogen receptor coded by a different gene. Tumor suppressor protein p53 is mutated in the majority (80%) of TNBC. p53, when mutated, loses its tumor suppression capabilities, and instead gains oncogenic or tumor-driving functions.  One of the major oncogenic functions of mutant p53 is to bind and inactivate another tumor suppressor named p73.  The Das laboratory has been focusing on the mechanisms underlying the estrogen receptor β-p53-p73 axis for discovering rational and effective therapeutic strategies against TNBC. (more…)