Transforming growth factor β1 is not a reliable biomarker for valvular fibrosis but could be a potential serum marker for invasiveness of prolactinomas (pilot study)

Abstract

BackgroundTransforming growth factor β1 (TGFβ1) signaling pathway is crucial for both human fibrogenesis and tumorigenesis.ObjectiveThis study aimed to investigate the usefulness of TGFβ1 and matrix metalloproteinase 2 (MMP2) as potential circulating markers for fibrotic valvular heart disease (FVHD) and invasiveness as well as of Fetuin A as a marker for calcification in patients with prolactinomas.DesignThe study population consisted of 147 subjects divided into four groups: 30 dopamine agonist (DA)-treated prolactinoma patients with proven FVHD and three control groups with normal echocardiograms: 43 DA-treated patients, 26 naïve patients, and 48 healthy subjects.ResultsWe observed significantly higher serum TGFβ1 levels in all three patient groups than in the healthy subjects (21.4±8.86 vs 19.1±9.03 vs 20.7±11.5 vs 15.8±7.2 ng/ml; P=0.032). Moreover, TGFβ1 levels were significantly higher in patients with macroprolactinomas and invasive prolactinomas than in those with microprolactinomas and noninvasive tumors respectively. In addition, a strong positive linear relationship between TGFβ1 levels and invasiveness score (ρ=0.924; P<0.001) and a moderate correlation between TGFβ1 levels and tumor volume (r=0.546; P<0.002) were observed in patients with invasive prolactinomas. By contrast, prolactin (PRL) levels exhibited a better correlation with tumor volume (r=0.721; P<0.001) than with invasiveness score (ρ=0.436; P<0.020). No significant difference was observed in Fetuin A levels between patients with FVHD and healthy controls. Results concerning MMP2 were unclear.ConclusionsTGFβ1, MMP2, and Fetuin A are not reliable biomarkers for valvular fibrosis and calcification in DA-treated patients with prolactinomas, but TGFβ1 may represent a useful serum marker for tumor invasiveness. The simultaneous determination of TGFβ1 and PRL levels could improve the noninvasive assessment of prolactinoma behavior.