Gene expression profiling analysis of MENX-associated rat pituitary adenomas contributes to understand molecular mechanisms of human pituitary adenomas

The present study aimed to screen potential genes associated with pituitary adenomas to obtain further understanding with regard to the pathogenesis of pituitary adenomas. The microarray GSE23207 dataset, containing 16 pituitary adenoma samples from multiple endocrine neoplasia syndrome-associated rats and 5 normal pituitary tissue samples, was downloaded from Gene Expression Omnibus. The Linear Models for Microarray Data package was used to identify the differentially-expressed genes (DEGs) with the cut-off criteria of a |log(2)fold change (FC)|>1 and adjusted P-values of <0.05. The potential functions of the DEGs were predicted by functional and pathway enrichment analysis with the Database for Annotation, Visualization and Integrated Discovery. Furthermore, the interaction associations of the up- and downregulated DEGs obtained from the Search Tool for the Retrieval of Interacting Genes database were respectively revealed by the protein-protein interaction networks visualized with Cytoscape. A total of 391 upregulated and 238 downregulated DEGs in were screened in the pituitary adenoma samples. The upregulated DEGs with a higher degree in the protein-protein interaction network (e.g., CCNA2, CCNB1 and CDC20) were significantly involved in cell cycle and cell division. Notably, PTTG1 was enriched in every functional term. These DEGs interacted with each other. The downregulated DEGs (e.g., GABRA1, GABRA4 and GABRB1) also interacted with each other, and were relevant to neuroactive ligand-receptor interaction; the DEG POU1F1, interacting with POMC, was correlated with the development of the pituitary gland, adenohypophysis and endocrine system. Certain DEGs, including CCNB1, CCNA2, CDC20, GABRA1, GABRA4, GABRB1, POU1F1 and POMC, and particularly PTTG1, were shown to be closely involved in the pathogenesis of pituitary adenomas.