Immunohistochemical Study of Colorectal Tumors for Expression of a Novel Transmembrane Carbonic Anhydrase, MN/CA IX, with Potential Value as a Marker of Cell Proliferation

• Published in: The American journal of pathology Vol. 153; no. 1; pp. 279 - 285
• Main Authors: Saarnio, Juha, Parkkila, Seppo, Parkkila, Anna-Kaisa, Haukipuro, Kari, Pastoreková, Silvia, Pastorek, Jaromir, Kairaluoma, Matti I., Karttunen, Tuomo J.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01-07-1998; ASIP; American Society for Investigative Pathology
• Subjects: Adenocarcinoma - enzymology; Adenocarcinoma - metabolism; Adenoma - enzymology; Adenoma - metabolism; Antigens, Neoplasm; Biological and medical sciences; Biomarkers, Tumor - metabolism; Carbonic Anhydrase IX; Carbonic Anhydrases; Cell Division; Colonic Polyps - enzymology; Colonic Polyps - metabolism; Colorectal Neoplasms - enzymology; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Immunoenzyme Techniques; Intestinal Mucosa - enzymology; Intestinal Mucosa - metabolism; Ki-67 Antigen - metabolism; Liver Neoplasms - enzymology; Liver Neoplasms - metabolism; Liver Neoplasms - secondary; Lymphatic Metastasis; Medical sciences; Neoplasm Proteins - metabolism; Regular; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Tumors; Immunohistochemistry; Cell proliferation; Rectal disease; Carcinoma; Isozyme; Biological marker; Lyases; Adenoma; Intestinal disease; Benign neoplasm; Colon; Diagnosis; Quantitative analysis; Polyp; Human; Transmembrane protein; Enzyme; Malignant tumor; Colonic disease; Pathology; Rectum; Digestive diseases; Carbonate dehydratase; Carbon-oxygen lyases; Hydro-lyases
• ISSN: 0002-9440; 1525-2191
• DOI: 10.1016/S0002-9440(10)65569-1

Carbonic anhydrase isoenzyme IX, MN/CA IX, is a recently discovered member of the carbonic anhydrase (CA) gene family with a suggested function in acid-base balance, intercellular communication, and cell proliferation. Increased expression of MN/CA IX has been observed with certain epithelial tumors. We investigated the expression of MN/CA IX in 69 colorectal neoplasms, consisting of 1 juvenile polyp, 8 hyperplastic polyps, 39 adenomatous lesions, 21 carcinomas, and 7 metastases. Tissue sections were immunostained with a monoclonal antibody specific to MN/CA IX. The proliferative activity of the tumor cells was evaluated by Ki-67 antigen immunoreactivity. The hyperplastic polyps showed a weak or moderate reaction for MN/CA IX only in the cryptal epithelium, as did the normal intestinal mucosa. The adenomas showed immunoreactivity mainly in the superficial part of the mucosa, whereas the distribution in the carcinomas and metastases was more diffuse. Comparative immunostaining of serial sections for Ki-67, a well established marker of cell proliferation, confirmed that MN/CA IX is expressed in areas with high proliferative capacity. Our results show abnormal MN/CA IX expression in colorectal neoplasms, suggesting its involvement in their pathogenesis. The co-occurrence of MN/CA IX and Ki-67 in the same tumor cells indicates its potential for use as a marker of increased proliferation in the colorectal mucosa.