title: Expression of a novel transmembrane carbonic anhydrase isozyme XII in normal human gut and colorectal tumors.
abstract: Carbonic anhydrase isozyme XII is a recently discovered member of the alpha-carbonic anhydrase gene family with a suggested role in von Hippel-Lindau gene-mediated carcinogenesis. Increased expression of its mRNA has been observed in renal and lung carcinomas. This paper presents the localization of CA XII in the normal human gut and in colorectal tumors. Immunohistochemistry performed using a polyclonal antibody raised against truncated CA XII revealed prominent polarized staining for CA XII in the basolateral plasma membrane of the enterocytes of the normal large intestine, the reaction being most intense in the surface epithelial cuff region. Most colorectal tumors displayed abnormal expression of CA XII; the most dramatic change was observed in the deep parts of the adenomatous mucosa, where the positive immunoreaction clearly increased along with the grade of dysplasia. Adenomas with severe dysplasia and carcinomas showed an equal, diffuse staining pattern. The results indicate region-specific regulation of CA XII expression along the cranial-caudal axis of the human gut, whereas its diffuse expression in the most malignant tumors seems to correlate with their biological behavior.
authors.affiliation: Department of Anatomy, University of Oulu, Oulu, Finland. kivelae@usa.net
authors.forename: A
authors.initials: A
authors.lastname: Kivelä
authors.forename: S
authors.initials: S
authors.lastname: Parkkila
authors.forename: J
authors.initials: J
authors.lastname: Saarnio
authors.forename: T J
authors.initials: TJ
authors.lastname: Karttunen
authors.forename: J
authors.initials: J
authors.lastname: Kivelä
authors.forename: A K
authors.initials: AK
authors.lastname: Parkkila
authors.forename: A
authors.initials: A
authors.lastname: Waheed
authors.forename: W S
authors.initials: WS
authors.lastname: Sly
authors.forename: J H
authors.initials: JH
authors.lastname: Grubb
authors.forename: G
authors.initials: G
authors.lastname: Shah
authors.forename: O
authors.initials: O
authors.lastname: Türeci
authors.forename: H
authors.initials: H
authors.lastname: Rajaniemi
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000473:pathology; D018256:Adenomatous Polyps / Q000201:enzymology; D002256:Carbonic Anhydrases / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D007417:Intestinal Polyps / Q000201:enzymology; D007420:Intestine, Large / Q000201:enzymology; D007422:Intestines / Q000201:enzymology*; D007527:Isoenzymes / Q000378:metabolism*; D008198:Lymph Nodes / Q000201:enzymology; D008207:Lymphatic Metastasis; D012016:Reference Values
chemical_list: D007527:Isoenzymes; D002256:Carbonic Anhydrases