Mary Helen Barcellos-Hoff

Mary Helen Barcellos-Hoff is a Professor at the University of California San Francisco, where her research investigates the dual role of ionizing radiation as both a carcinogen and therapeutic agent. Her work focuses on TGFβ signaling in DNA damage repair, tumor microenvironment regulation, and radiation biology across breast, brain, lung, and ovarian cancers.

• University of Chicago, A.B., 1978 (Biopsychology)
• UCSF, Ph.D., 1986 (Experimental Pathology)
• UC Berkeley, Postdoctoral training, 1988 (Biophysics)

Her research demonstrates that TGFβ mediates DNA repair via homologous recombination and end-joining pathways while modulating immune cell phenotypes in irradiated tumors. She uses mouse models of breast carcinogenesis to study radiation-induced stromal-epithelial interactions and BRCA1-TGFβ interplay, translating findings to clinical applications of TGFβ inhibitors.

Recent articles highlight her proteogenomic analyses of ovarian cancer, TGFβ signaling monitoring in irradiated tumors, and dual inhibition strategies for TGFβ and PD-L1 in immunotherapy. Key trends include radiation-induced inflammation, DNA repair deficits, and tumor-immune co-evolution.

• Basic Science Research Award, UCSF (1982, 1984)
• NIH Fellowship Biophysics Training Grant (1986-1988)
• Chair, Gordon Research Conference on Mammary Gland Biology (2003-2008)
• Chief Scientist, DOE OBER Low Dose Program (2012-2013)

She has secured continuous NIH/NCI funding since 1991, including current projects on tumor immune microenvironment dynamics (R01 CA270332, 2022-2027) and collaborations with Roche/Genentech, Varian Medical Systems, and DOD-BCRP. Her work bridges basic and translational cancer research.