title: Analysis of IMP3 expression in normal and neoplastic human pituitary tissues.
abstract: Insulin-like growth factor II mRNA-binding protein 3 (IMP3) is an oncofetal protein highly expressed in fetal tissue and malignant tumors but rarely found in adult benign tissues. In various tumors, IMP3 expression is correlated with increased tumor aggressiveness and reduced overall survival. To our knowledge, IMP3 expression has not been investigated in pituitary tumors. We analyzed the immunohistochemical expression of IMP3 in five normal pituitary tissues and 75 pituitary tumors (64 adenomas and 11 carcinomas) to determine if specific tumor types expressed IMP3 and if there were differences in IMP3 expression between adenomas and carcinomas. Immunohistochemical analysis showed that IMP3 was positive in four (80%) normal pituitaries with focal stain in a subset of normal anterior pituitary cells. IMP3 was expressed in 31% (20/64) of adenomas and in 36% (4/11) of carcinomas. A slightly higher level of IMP3 expression was observed in PRL-GH-TSH adenomas compared to the other types of pituitary adenomas. Expression of IMP3 was not significantly higher in carcinomas than in adenomas (p = 0.737). RT-PCR and Western Blotting supported the heterogeneous expression of IMP3. These results indicate that IMP3 is expressed both in normal and in neoplastic pituitary gland tissues without significant differences in expression levels in pituitary carcinomas.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA.
authors.forename: Alberto
authors.initials: A
authors.lastname: Righi
authors.forename: Shuya
authors.initials: S
authors.lastname: Zhang
authors.forename: Long
authors.initials: L
authors.lastname: Jin
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: Kalman
authors.initials: K
authors.lastname: Kovacs
authors.forename: Gabor
authors.initials: G
authors.lastname: Kovacs
authors.forename: Miklos I
authors.initials: MI
authors.lastname: Goth
authors.forename: Marta
authors.initials: M
authors.lastname: Korbonits
authors.forename: Ricardo V
authors.initials: RV
authors.lastname: Lloyd
mesh_terms: D015153:Blotting, Western; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D010911:Pituitary Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D016601:RNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C498780:IGF2BP3 protein, human; D012333:RNA, Messenger; D016601:RNA-Binding Proteins