ABSTRACT
<p><b>OBJECTIVE</b>To investigate the correlation between signal transducer and activator of transcription 3 (STAT3) expression and pituitary adenoma subtypes.</p><p><b>METHOD</b>The STAT3 expression profiles in different pituitary adenomas from 74 patients were determined using quantificational real-time polymerase chain reaction,Western blot,and immunohistochemistry.</p><p><b>RESULTS</b>Expression of STAT3 was observed in all pituitary adenoma subtypes. The STAT3 expression level was highest in growth hormone adenoma when compared with other tumors including prolactin,follicle-stimulating hormone/luteinizing hormone-secreting adenoma,and adrenocorticotrophic hormone-secreting adenoma. The follicle-stimulating hormone/luteinizing hormone adenomas exhibited the lowest STAT3 expression levels.</p><p><b>CONCLUSION</b>STAT3 is differentially expressed in pituitary adenoma subtypes, suggesting the cell-specific features of STAT3 regulation,although further investigations are still warranted to clarify the underlying mechanisms.</p>