Analyses of the APC and TGF-β Type II Receptor Genes, and Microsatellite Instability in Mucosal Colorectal Carcinomas |
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Authors: | Osmar Kenji Yagi Yoshimitsu Akiyama Yasuo Ohkura Shin-ichi Ban Mitsuo Endo Kiyoshi Saitoh Yasuhito Yuasa |
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Institution: | First Department of Surgery, Tokyo Medical and Dental University School of Medicine, 1–5–45 Yushima, Bunkyo–ku, Tokyo 113;Department of Hygiene and Oncology, Tokyo Medical and Dental University School of Medicine, 1–5–45 Yushima, Bunkyo–ku, Tokyo 113;Department of Pathology, Tokyo Metropolitan Cancer Survey Center, 2–5 Surugadai, Kanda, Chiyoda–ku, Tokyo 101;Second Department of Pathology, Saitama Medical School, 38 Moro–Honcho, Moroyama–cho, Iruma–gun, Saitama 350–4;Department of Pathology, International Medical Center of Japan, Toyama, Shinjuku–ku, Tokyo 162 |
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Abstract: | APC and transforming growth factor-β type II receptor (TGF-β RII) gene mutations, and microsatcllitc instability have been found in sporadic colorectal carcinomas. To clarify further the early alterations in colorectal carcinogenesis, we investigated these genetic changes in 23 protruding- and 24 superficial-type mucosal colorectal carcinomas. TGF-β RII gene mutations and microsatellite instability were rarely found in these lesions. Nevertheless, APC was mutated in 16 of the 47 (34.0%) mucosal colorectal carcinomas and was significantly more frequently mutated in protruding- (I) and superficial elevated-type (Ila) (14/32,43.8%) than in other superficial-type (IIa+IIc, IIb, IIc, and IIc+IIa) (2/ 15,13.3%) mucosal colorectal carcinomas (P<0.04). These results indicate that the APC gene may be involved from the beginning in the tumorigenesis of many early colorectal carcinomas, particularly of the protruding and superficial elevated types. However, there might be a distinct pathway for other superficial-type colorectal carcinomas, possibly not involving APC as an initial step of tumorigenesis. |
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Keywords: | Early colorectal carcinoma APC Microsatellite instability Transforming growth factor-β type II receptor gene K-ras |
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