Expression Of Pituitary Tumor Transforming Gene And Matrix Metalloproteinases In Human Pituitary Adenomas: Relationships To Clinical Tumor Behaviors

Objective Pituitary adenomas (PAs) are the most common tumors of the saddle area. Despite their benign histological characteristics, pituitary adenomas often invade into surrounding tissues complicating the therapeutic strategy. The key to success is undoubtedly early diagnosis and selection of an appropriate therapy. In this study, we have examined the potential relationship between the levels of pituitary tumor transforming gene (PTTG), matrix metalloproteinases (MMPs) expression and some aspects of pituitary tumor behaviors, and provided the theoretical basis for the diagnosis and treatment of invasive PAs.Materials and Methods Fifty surgically resected pituitary adenoma tissue samples;including 26 invasive PAs and 24 non-invasive PAs. Tumor invasion was determined by assessment of preoperative magnetic resonance imaging and intraoperative inspection. Envision immunohistochemical technique was used to detect the expression ofPTTG, MMPs and vascular endothelial growth factor (VEGF) in all of the samples. The relationships between PTTQ MMPs, VEGF expression and tumor invasion and the relationship between PTTG and MMPs in invasive PAs were analyzed.Results (1) The positive expression rate of PTTG in invasive PAs (n=26) and non-invasive PAs (n=24) was 96.2%, 87.5% respectively. There was significant difference between two groups (P=0.016 < 0.05). The positive expression rate of MMP-2 in two groups was 92.3% ^ 75%(P=0.016 < 0.05) respectively. The positive expression rate of MMP-9 was 96.2% > 79.2% (P=0.009 < 0.05). The positive expression rate of VEGF was 100% > 95.8% (P=0.046 < 0.05). (2) A positive correlation was demonstrated between FTTG expression and MMP-2, MMP-9 expression in invasive PAs (rs=0.988, P=0.000 < 0.01;rs=0.955, P=0.000 < 0.01. Spearman).Conclusions (1) There were high expression level of PTTQ MMP-2, MMP-9 and VEGF in PAs, especially in invasive PAs. There was a significant correlation between invasive characters of PAs and the over expression of PTTG and MMPs. So we think that PTTG and MMPs can serve as a biological marker of invasive PAs, which can help us to diagnose invasive PAs. (2) There is a positive correlation between PTTG and MMP-2, MMP-9 expression in invasive PAs. But the mechanism is not unclear. 3) Further research on the PTTG, MMP-2, MMP-9 andVEGF in PAs would provide the theoretical basis for biological treatment of invasive PAs.