1. Academic Validation
  2. G9a Promotes Breast Cancer Recurrence through Repression of a Pro-inflammatory Program

G9a Promotes Breast Cancer Recurrence through Repression of a Pro-inflammatory Program

  • Cell Rep. 2020 Nov 3;33(5):108341. doi: 10.1016/j.celrep.2020.108341.
Nathaniel W Mabe 1 Nina Marie G Garcia 1 Shayna E Wolery 1 Rachel Newcomb 1 Ryan C Meingasner 1 Brittany A Vilona 1 Ryan Lupo 1 Chao-Chieh Lin 2 Jen-Tsan Chi 2 James V Alvarez 3
Affiliations

Affiliations

  • 1 Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA.
  • 2 Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710, USA; Center for Genomic and Computational Biology, Duke University, Durham, NC 27710, USA.
  • 3 Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA. Electronic address: james.alvarez@duke.edu.
Abstract

Dysregulated gene expression is a common feature of Cancer and may underlie some aspects of tumor progression, including tumor relapse. Here, we show that recurrent mammary tumors exhibit global changes in gene expression and histone modifications and acquire dependence on the G9a Histone Methyltransferase. Genetic ablation of G9a delays tumor recurrence, and pharmacologic inhibition of G9a slows the growth of recurrent tumors. Mechanistically, G9a activity is required to silence pro-inflammatory cytokines, including tumor necrosis factor (TNF), through H3K9 methylation at gene promoters. G9a inhibition induces re-expression of these cytokines, leading to p53 activation and Necroptosis. Recurrent tumors upregulate receptor interacting protein kinase-3 (RIPK3) expression and are dependent upon RIPK3 activity. High RIPK3 expression renders recurrent tumors sensitive to Necroptosis following G9a inhibition. These findings demonstrate that G9a-mediated silencing of pro-necroptotic proteins is a critical step in tumor recurrence and suggest that G9a is a targetable dependency in recurrent breast Cancer.

Keywords

G9a; RIPK3; breast cancer; collateral sensitivity; epigenetics; necroptosis; recurrence.

Figures
Products