Integrative proteomics and transcriptomics identify novel invasive-related biomarkers of non-functioning pituitary adenomas

Non-functioning pituitary adenomas (NFPAs) are usually macroadenomas and display invasion into surrounding tissues. The treatment for invasive NFPAs is still challenging. This study describes the differential patterns of gene expression between invasive and non-invasive NFPAs and identifies novel biomarkers involved in invasion of NFPAs for diagnosis and treatment. Using gene microarray technology, we examined the gene expression profile and found 1160 differentially expressed messenger RNA (mRNA) between invasive and non-invasive NFPAs. Then, we examined the protein profile by liquid chromatography tandem mass spectrometry (LC-MS/MS) and found 433 differentially expressed proteins between invasive and non-invasive NFPAs. Subsequently, we integrated the proteomics and transcriptomics datasets and identified 29 common changed molecules. Through bioinformatics analysis using Ingenuity Pathway Analysis (IPA) software, we showed that the 29 molecules were enriched in 25 canonical signaling pathways, 25 molecular and cellular functions, and 2 networks. Eight genes were identified involved in the invasion function by the molecular and cellular functions analysis, including CAT, CLU, CHGA, EZR, KRT8, LIMA1, SH3GLB2 and SLC2A1. Furthermore, we validated the decreased CHGA expression and increased CLU expression in invasive NFPAs by qRT-PCR and Western blot. Our study demonstrated that integration of proteomics and transcriptomics could prove advantageous for accelerating tumor biomarker discovery and CHGA and CLU might be important novel biomarkers and therapeutic targets for invasion of NFPAs.