Abstract 2123: Glycine decarboxylase regulates renal carcinoma progression via interferon stimulated gene factor 3-mediated pathway

Glycine decarboxylase (GLDC) is a mitochondrial enzyme that mediates the degradation of glycine as part of the glycine cleavage system; it is implicated as a tumor suppressor in hepatocellular carcinoma but as an oncogene in the lung cancer. Although GLDC expression in the kidney is second highest next to the liver, very little is known as to the role of GLDC in the kidney. Thus, this study was designed to determine the role of GLDC in the renal carcinoma. We found markedly increased expressions of GLDC in patients with renal cell carcinoma (RCC) classified as poor-risk group based on the Memorial Sloan Kettering Cancer Center prognostic model. In vitro studies revealed that cellular proliferation, colony formation, and migration were decreased in GLDC-deficient renal carcinoma cells while those were increased in GLDC-overexpressing renal carcinoma cells. In vivo xenograft studies with GLDC-deficient and -overexpressing cells also revealed that tumor sizes were noticeably decreased in GLDC-deficient cell-injected mice while those were increased in GLDC-overexpressing cell-injected mice. Mechanistically, we found GLDC regulates renal carcinoma progression via interferon (IFN) stimulated gene factor 3 (ISGF3)-mediated pathway. Poly-IC induced mRNA expression of IFN-α more strongly in GLDC-deficient cells. Expressions of IRF9 and STAT2 were increased in GLDC-deficient cells while those were decreased in GLDC-overexpressing cells. Interferon-responsive genes (IFIT1, IFI44, IFI44L, and IFI27) were also regulated by GLDC as evidenced by increased mRNA expressions in GLDC-deficient cells and increased mRNA expressions in GLDC-overexpressing cells. Knock-down of IRF9 and STAT2 in GLDC-deficient cells reversed decreased cellular proliferation, colony formation, and migration. In summary, the data in this study indicates that GLDC regulates renal carcinoma progression via ISFG3-medated pathway and lay a scientific foundation that could support a therapeutic strategy that targets GLDC for the treatment of renal carcinoma. Citation Format: Jin Young Kim, Mai Thi Tuyet Pham, Byung Hoon Kim, Ji Hae Seo, Sojin Shin, Eunyoung Ha. Glycine decarboxylase regulates renal carcinoma progression via interferon stimulated gene factor 3-mediated pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr