One-carbon metabolism plays a central role in a broad array of metabolic processes required for the survival and growth of tumor cells. However, the molecular basis of how one-carbon metabolism may influence RNA methylation and tumorigenesis remains largely unknown. Here we show MTHFD2, a mitochondrial enzyme involved in one-carbon metabolism, contributes to the progression of renal cell carcinoma (RCC) via a novel epitranscriptomic mechanism that involves HIF-2α. We found that expression of MTHFD2 was significantly elevated in human RCC tissues, and MTHFD2 knockdown strongly reduced xenograft tumor growth. Mechanistically, using an unbiased methylated RNA immunoprecipitation sequencing (meRIP-Seq) approach, we found that MTHFD2 plays a critical role in controlling global N6-methyladenosine (m6A) methylation levels, including the m6A methylation of HIF-2α mRNA, which results in enhanced translation of HIF-2α. Enhanced HIF-2α translation, in turn, promotes the aerobic glycolysis, linking one-carbon metabolism to HIF-2α-dependent metabolic reprogramming through RNA methylation. Our findings also suggest that MTHFD2 and HIF-2α form a positive feedforward loop in RCC, promoting metabolic reprograming and tumor growth. Taken together, our results suggest that MTHFD2 links RNA methylation status to the metabolic state of tumor cells in RCC.
Oncogene. 2019 Jul 09 [Epub ahead of print]
Nathanael H Green, Daniel L Galvan, Shawn S Badal, Benny H Chang, Valerie S LeBleu, Jianyin Long, Eric Jonasch, Farhad R Danesh
Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, 77030, USA., Section of Nephrology, the University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA., Department of Medicine and Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA., Department of Cancer Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA., Department of Genitourinary Oncology, the University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA., Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, 77030, USA. .