Another small molecule in the oncometabolite mix: L-2-Hydroxyglutarate in kidney cancer

Alterations in metabolism are now considered a hallmark of cancer. One of the clearest links between metabolism and malignancy are oncometabolites. To date, several putative oncometabolites with transforming properties have been identified in the context of tumors due to both gain and loss of function mutations in genes encoding enzymes of intermediary metabolism. Through an unbiased metabolomics approach, we identified elevations of the metabolite 2-hydroxyglutarate (2-HG) in the most common histology of kidney cancer that is among the most common malignancies in both men and women. Subsequent analyses demonstrate that the predominant enantiomer of 2-HG elevated in renal cancer is the L(S) form. Notably, elevations of L-2HG are due in part to loss of expression of the L-2HG dehydrogenase (L2HGDH) which normally serves as an enzyme of "metabolite repair" to keep levels of this metabolite from accumulating. Lowering L-2HG levels in RCC through re-expression of L2HGDH mitigates tumor phenotypes and reverses epigenetic alterations known to be targeted by oncometabolites. These data add to the growing body of evidence that metabolites, similarly to oncogenes and oncoproteins, can play a role in tumor development and/or progression. As such, they represent a unique opportunity to utilize these findings in the clinic setting.