title: Altered expression patterns of heterogeneous nuclear ribonucleoproteins A2 and B1 in the adrenal cortex.
abstract: Several proteins implicated in hormonogenesis of the adrenal cortex have alternatively spliced isoforms, which respond differently to adrenocorticotropic hormone (ACTH). Heterogeneous nuclear ribonucleoproteins A2 and B1 are among the abundant pre-mRNA-binding proteins involved in alternative splicing. We examined the expression of A2 and B1 in normal adrenal cortex and tumors. B1 was variably expressed in the zona fasciculata-reticularis, although A2 was diffusely expressed in the three zones. B1 was more abundant in compact cells than clear cells, and B1 expression was frequent in the zona reticularis, which consists mainly of compact cells. In three kinds of cortical adenomas autonomously producing hormones, B1 was generally overexpressed and there were no significant differences among them. In cortisol-producing tumors, non-tumor parts of the cortex, which were generally atrophic due to low ACTH, had less B1 protein than normal adrenals. These results suggested a correlation between B1 expression and the hormonal activity responding to ACTH. In vitro ACTH stimulation induced a biphasic expression of B1 in an H295R cortical carcinoma cell line, and it paralleled hormonogenesis. Conclusively, B1 expression varied in relation to the hormonal activity responding to the ACTH, and it may provide a key to elucidating the splicing mechanisms involved in hormonogenesis.
authors.affiliation: Institute of Basic Medical Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8575, Japan.
authors.forename: WenWen
authors.initials: W
authors.lastname: Wu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamma
authors.forename: Masachika
authors.initials: M
authors.lastname: Fujiwara
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Yano
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Satoh
authors.forename: Hisatoh
authors.initials: H
authors.lastname: Hara
authors.forename: Tohru
authors.initials: T
authors.lastname: Yashiro
authors.forename: Ei
authors.initials: E
authors.lastname: Ueno
authors.forename: Yuji
authors.initials: Y
authors.lastname: Aiyoshi
mesh_terms: D000302:Adrenal Cortex / Q000378:metabolism*; D000306:Adrenal Cortex Neoplasms / Q000378:metabolism*; D017398:Alternative Splicing; D045744:Cell Line, Tumor; D004591:Electrophoresis, Polyacrylamide Gel; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry
chemical_list: D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B