Abstract PR011: Histone demethylase KDM5D drives sex-specific differences in colorectal cancer

Abstract Gender exerts a profound impact on cancer incidence, spectrum and outcomes, yet the molecular genetic bases of such sex differences are ill-defined and presumptively ascribed to X-chromosome genes and sex hormones. Such sex differences are particularly prominent in colorectal cancer (CRC) where men experience higher metastases and mortality. A murine CRC model, engineered with an inducible oncogenic Kras transgene (KRAS*) and conditional null alleles of Apc and Trp53 tumor suppressors (designated iKAP), revealed higher metastases and worse outcomes specifically in males with KRAS* CRC. Integrated cross-species molecular and transcriptomic analyses identified Y-chromosome gene histone demethylase KDM5D as a transcriptionally up-regulated gene driven by KRAS*-mediated activation of the STAT4 transcription factor. KDM5D-dependent chromatin mark and transcriptome changes showed repression of regulators of epithelial cell tight junction and MHC class I complex components. Deletion of KDM5D in iKAP cancer cells increased tight junction integrity, decreased cell invasiveness, and enhanced cancer cell killing by CD8+ T cells. Conversely, iAP mice engineered with a Kdm5d transgene to provide constitutive KDM5D expression specifically in iAP cancer cells exhibited an increased propensity for more invasive tumors in vivo. Thus, KRAS*-STAT4-mediated upregulation of Y chromosome KDM5D contributes significantly to the sex differences in KRAS* CRC via its disruption of cancer cell adhesion properties and tumor immunity, thus providing an actionable therapeutic strategy for metastasis risk reduction for men afflicted with KRAS* CRC. Citation Format: Jiexi Li, Zhengdao Lan, Wenting Liao, James W. Horner, Jielin Liu, Shan Jiang, Hong S. Shim, Max Slotnik, Kyle A. LaBella, Wen-Hao Hsu, Denise J. Spring, Y. Alan Wang, Ronald A. DePinho. Histone demethylase KDM5D drives sex-specific differences in colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr PR011.