Proteomic analysis of prolactinoma cells by immuno-laser capture microdissection combined with online two-dimensional nano-scale liquid chromatography/mass spectrometry

Proteins from immuno-LCM captured prolactin cells were digested; resulting peptides were separated by two dimensional-nanoscale liquid chromatography (2D-nanoLC/MS) and characterized by tandem mass spectrometry. All MS/MS spectrums were analyzed by SEQUEST against the human International Protein Index database and a specific prolactinoma proteome consisting of 2243 proteins was identified. This collection of identified proteins by far represents the largest and the most comprehensive database of proteome for prolactinoma. Category analysis of the proteome revealed a widely unbiased access to various proteins with diverse functional characteristics.This manuscript described a more comprehensive proteomic profile of prolactinomas compared to other previous published reports. Thanks to the application of immuno-LCM combined with online two-dimensional nano-scale liquid chromatography here permitted identification of more proteins and, to our best knowledge, generated the largest prolactinoma proteome. This enlarged proteome would contribute significantly to further understanding of prolactinoma tumorigenesis which is crucial to the management of prolactinomas.Prolactinomas are the most common pituitary tumors, representing 25%-44% of all pituitary adenoma cases [1]. Although most are pathologically benign and grow slowly, prolactinomas show many symptoms in patients: amenorrhea, galactorrhea and dysgenesis in female patients and infertility and erectile dysfunction in male. Moreover, a number of prolactinomas belie their histology by perisellar invasion and postoperative recurrence. Comprehensive molecular dissection of prolactinoma pathogenesis is demanded for further understanding of this kind of tumors. Increasing evidences suggest that characterization at DNA or RNA level alone would not be sufficient to elucidate the mechanisms of this disease as lots of posttranslational modifications exist and pituitary adenoma proteomics would offer an efficient means for a com