The pathway regulating RhoA activity to predict the survival of gastric cancers.

49Background: RhoA mutation has been intensively studied for its association with progression in gastric cancer (GC). Recently, mutations in a pathway regulating RhoA activity have been identified as a predictive biomarker in breast cancer. Herein, our aim is to investigate the role of such pathway in the progression of patients with GC receiving chemotherapies. Methods: Two non-overlapped TCGA cohorts (TCGA1, downloaded from GDC, N = 123 and TCGA2, from Cbioportal, N = 312) and a third ACRG cohort (Nature Medicine 2015, N = 295) were assessed for their mutation status of RhoA pathway; meanwhile, a cohort from Chinese GC (CGC, N = 57) was examined with whole exome sequencing (WES). A subset of “Regulation of RhoA activity” pathway (NCI Pathway Interaction), denoted as RhoA_S, was derived from analyzing the expression of RhoA and mutations in TCGA1 without referring to its survival data. Subsequently, RhoA_S was evaluated for its prediction of overall survival (OS) in the above four GC cohorts receiving ch...