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

Abstract

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 (SST1-5) and dopamine (DRDs) providing a rationale for the use of dopamine agonists and somatostatin analogues. Here, we systematically assessed SST1-5 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. SST1-5 expression was also evaluated by immunohistochemistry. SST3 was the predominant SST subtype detected, followed by SST2, SST5, and SST1. DRD2 was the dominant DRD subtype, followed by DRD4, DRD5, and DRD1. A substantial proportion of NFPTs displayed marked expression of SST2 and SST5. No major association between SSTs and DRDs expression and clinical and molecular aggressiveness features was observed in NFPTs.

Treatment of Aggressive Pituitary Adenomas: A Case-Based Narrative Review

“…Although pasireotide has a higher affinity for SST3 and has been shown to inhibit NFA cell viability in vitro ( 61 ), no clinical studies have confirmed control of adenoma growth. Of note, there was no clear association between SST expression and clinical features of aggressiveness in 113 NFAs, of which 46% were invasive ( 62 ).…”

Current and Emerging Medical Therapies in Pituitary Tumors

“…There are currently few medical therapies available for the treatment of non-functioning pituitary tumors (NFPT), which contrast with the high representation of this subtype among newly diagnosed PT [218]. NFPT arising from the gonadotroph lineage are characterized by predominant expression of SST3 over the other subtypes of SST, even though the SST expression profile of the tumor was not associated with its aggressivity [219]. In an elegant study, Vàzquez-Borrego et al tested a new SST3 peptide agonist, over the growth of NFPT [220].…”

Primary hypothyroidism and postmenopause as the causes of delayed diagnosis of panhypopituitarism in a patient with nonfunctional pituitary adenoma

“…При наличии гормонально-неактивной макроаденомы гипофиза и отсутствии абсолютных показаний к нейрохирургическому лечению может быть рекомендован прием агонистов дофамина с антипролиферативной целью, с достижением дозы каберголина 3,5 мг в неделю [16]. Назначение агонистов дофамина пациентам с гормонально-неактивными образованиями гипофиза обосновано экспрессией дофаминовых рецепторов 2 типа в данном типе опухоли [18]. Несколько клинических исследований показало, что назначение бромокриптина в дозе от 15 до 60 мг в сутки при первичном лечении гормонально-неактивных образований гипофиза приводило к стабилизации размеров опухоли.…”