title: Presence of HIF-1 and related genes in normal mucosa, adenomas and carcinomas of the colorectum.
abstract: Expression of the transcription factor hypoxia-inducible factor 1 (HIF-1), which plays a key role in cellular adaptation to hypoxia, was investigated in normal colorectal mucosa (ten), adenomas (61), and carcinomas (23). Tissue samples were analyzed for HIF-1 alpha, its upstream regulators, von Hippel-Lindau factor, AKT, and mammalian target of rapamycin (mTOR) and its downstream targets glucose transporter 1 (GLUT1), carbonic anhydrase IX, stromal-cell-derived factor 1 (SDF-1) by immunohistochemistry. In normal colorectal mucosa, HIF-1 alpha was observed in almost all nuclei of surface epithelial cells, probably secondary to a gradient of oxygenation, as indicated by pimonidazole staining. The same staining pattern was present in 87% of adenomas. In carcinomas, HIF-1 alpha was present predominantly around areas of necrosis (78%). Active AKT and mTOR, were present in all adenomas, carcinomas, and in normal colorectal mucosa. GLUT1 and SDF-1 were present in the normal surface epithelium of all adenoma cases, whereas in the carcinoma GLUT1 was located around necrotic regions and SDF-1 was present in all epithelial cells. In conclusion, HIF-1 alpha appears to be physiologically expressed in the upper part of the colorectal mucosa. The present observations support that upregulation of HIF-1 alpha and its downstream targets GLUT1 and SDF-1 in colorectal adenomas and carcinomas may be due to hypoxia, in close interaction with an active phosphatidylinositol 3-kinases-AKT-mTOR pathway.
authors: Department of Pathology, VU University Medical Centre, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
authors: Astrid E
authors: AE
authors: Greijer
authors: Pien M
authors: PM
authors: Delis-van Diemen
authors: Remond J A
authors: RJ
authors: Fijneman
authors: Rachel H
authors: RH
authors: Giles
authors: Emile E
authors: EE
authors: Voest
authors: Victor W M
authors: VW
authors: van Hinsbergh
authors: Gerrit A
authors: GA
authors: Meijer
mesh_terms: D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000235:genetics / Q000378:metabolism; D054377:Chemokine CXCL12 / Q000235:genetics / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D015972:Gene Expression Regulation, Neoplastic; D051272:Glucose Transporter Type 1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D051058:Oncogene Protein v-akt / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases
chemical_list: D000951:Antigens, Neoplasm; D054377:Chemokine CXCL12; D051272:Glucose Transporter Type 1; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C495677:SLC2A1 protein, human; D011494:Protein Kinases; C546842:MTOR protein, human; D051058:Oncogene Protein v-akt; D058570:TOR Serine-Threonine Kinases; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases