Quantitative Analysis of Somatostatin and Dopamine Receptors Gene Expression Levels in Non-functioning Pituitary Tumors and Association with Clinical and Molecular Aggressiveness Features

The primary treatment for non-functioning pituitary tumors (NFPTs) is surgery, but it is often unsuccessful. Previous studies have reported that NFPTs express receptors for somatostatin (SST(1-5)) and dopamine (DRDs) providing a rationale for the use of dopamine agonists and somatostatin analogues. Here, we systematically assessed SST(1-5) and DRDs expression by real-time quantitative PCR (RT-qPCR) in a large group of patients with NFPTs (n = 113) and analyzed their potential association with clinical and molecular aggressiveness features. SST(1-5) expression was also evaluated by immunohistochemistry. SST(3) was the predominant SST subtype detected, followed by SST(2), SST(5), and SST(1). DRD2 was the dominant DRD subtype, followed by DRD4, DRD5, and DRD1. A substantial proportion of NFPTs displayed marked expression of SST(2) and SST(5). No major association between SST(s) and DRDs expression and clinical and molecular aggressiveness features was observed in NFPTs.