Gene expression profiling of fast- and slow-growing non-functioning gonadotroph pituitary adenomas

Abstract

ObjectiveReliable biomarkers associated with aggressiveness of non-functioning gonadotroph adenomas (GAs) are lacking. As the growth of tumor remnants is highly variable, molecular markers for growth potential prediction are necessary. We hypothesized that fast- and slow-growing GAs present different gene expression profiles and reliable biomarkers for tumor growth potential could be identified, focusing on the specific role of epithelial-mesenchymal transition (EMT).Design and methodsEight GAs selected for RNA sequencing were equally divided into fast- and slow-growing group by the tumor volume doubling time (TVDT) median (27.75 months). Data were analyzed by tophat2, cufflinks and cummeRbund pipeline. 40 genes were selected for RT-qPCR validation in 20 GAs based on significance, fold-change and pathway analyses. The effect of silencingMTDH(metadherin) andEMCN(endomucin) onin vitromigration of human adenoma cells was evaluated.Results350 genes were significantly differentially expressed (282 genes upregulated and 68 downregulated in the fast group,P-adjusted <0.05). Among 40 selected genes, 11 showed associations with TVDT (−0.669<R<−0.46,P < 0.05). These werePCDH18, UNC5D, EMCN, MYO1B, GPM6Aand six EMT-related genes (SPAG9, SKIL, MTDH, HOOK1, CNOT6LandPRKACB).MTDH, but notEMCN, demonstrated involvement in cell migration and association with EMT markers.ConclusionsFast- and slow-growing GAs present different gene expression profiles, and genes related to EMT have higher expression in fast-growing tumors. In addition toMTDH, identified as an important contributor to aggressiveness, the other genes might represent markers for tumor growth potential and possible targets for drug therapy.