Recurrent GNAQ mutation encoding T96S in natural killer/T cell lymphoma

Natural killer/T cell lymphoma (NKTCL) is a rare and aggressive malignancy with a higher prevalence in Asia and South America. However, the molecular genetic mechanisms underlying NKTCL remain unclear. Here, we identify somatic mutations of GNAQ (encoding the T96S alteration of G alpha q protein) in 8.7% (11/127) of NKTCL patients, through whole-exome/targeted deep sequencing. Using conditional knockout mice (Ncr1-Cre-Gnaq(fl/fl)), we demonstrate that G alpha q deficiency leads to enhanced NK cell survival. We also find that G alpha q suppresses tumor growth of NKTCL via inhibition of the AKT and MAPK signaling pathways. Moreover, the G alpha q T96S mutant may act in a dominant negative manner to promote tumor growth in NKTCL. Clinically, patients with GNAQ T96S mutations have inferior survival. Taken together, we identify recurrent somatic GNAQ T96S mutations that may contribute to the pathogenesis of NKTCL. Our work thus has implications for refining our understanding of the genetic mechanisms of NKTCL and for the development of therapies.