GCDH Mediates Histone Crotonylation to Regulate GLS1 Expression and Promote Reprogramming of Glutamine Metabolism in Breast Cancer

Background: Metabolic remodeling plays critical role in cancer development and targeting the glutamine metabolism is a promising strategy for cancer therapy. Histone crotonylation is a novel histone modification that has been confirmed to play roles in multiple physiological and pathological processes, making it a hot topic and frontier area of research. In this study, we aimed to investigate the potential effects and regulatory mechanisms of glutaryl-CoA dehydrogenase (GCDH), a reported crotonylation regulator, during breast cancer growth. Methods: Breast cancer cells were depleted of GCDH, then in vitro cell growth was detected by cell counting kit-8 (CCK-8) and EdU assay, and in vivo cell growth was measured by a xenograft tumor model. The intracellular glutamine, glutamate acid, ATP and α-Ketoglutaric acid (α-KG) levels were detected to analyze glutamine metabolism. The protein expression and histone crotonylation level were detected using western blot assay. The enrichment of crotonylation at histone was detected using chromatin immunoprecipitation (ChIP) assay. The promoter activity of GLS1 was measured by luciferase reporter gene assay. Results: GCDH depletion suppressed the in vitro and in vivo growth of breast cancer cells. Knockdown of GCDH reduced glutamine metabolism and ATP production in breast cancer cells. The enrichment of H3K27 crotonylation on GLS1 promoter region was notably reduced under depletion of GCDH. The promoter activity of GLS1 was significantly suppressed by siGCDH. The overexpression of GLS1 in breast cancer cells could recover the protein expression of GLS1 that suppressed by siGCDH. Depletion of GLS1 repressed the proliferation and glutamine metabolism of breast cancer cells, whereas overexpression of GCDH abolished these effects. Conclusion: GCDH modulates the histone crotonylation and expression of GLS1 to mediate the growth and glutamine metabolism of breast cancer cells.