Identification of distinct molecular signatures in AIP mutation-positive familial isolated pituitary adenomas

The aim of this study was to perform comparative gene expression analysis of AIP mutation-positive, AIP mutation-negative familial and sporadic somatotroph tumours to discover the genes/pathways responsible for the aggressive phenotype. Gene expression analysis was performed on 25 pituitary samples (five normal pituitary, six AIPpos GH, three AIPneg GH, four sporadic GH, two AIPneg familial NFPA and five sporadic NFPA adenomas) using the Affymetrix human Gene Chip HG-U133 Plus 2.0 array. In order to identify differentially expressed genes both functional non-functional pituitary tumours were compared with normal pituitary samples. Four samples (one AIPpos GH2, one sporadic GH3, one AIPneg familial NFPA2 and one sporadic NFPA5) did not pass the Affymetrix quality control assessment therefore, omitted for further analysis.