Effects of expression of hRFI on adenoma formation and tumor progression in colorectal adenoma-carcinoma sequence.
For colorectal carcinomas as well as colonic polyps we investigated the expression of a newly discovered gene, hRFI, which is isolated by the yeast two-hybrid screening using hTid as a bait and expressed highly in esophageal carcinomas. Immunohistochemical staining was performed on 48 colorectal carcinomas and 77 colorectal polyps consisting of 70 adenomas and 7 hyperplastic polyps using the antibody of hRFI. We analyzed the expression of hRFI and the correlation between the percentage of staining of each and their clinico-pathological characteristics. Protein coding by hRFI was specifically and diffusely expressed in most of the cancerous regions of the colorectum. Also, in the early stage of colorectal adenomas, staining of hRFI was focal, and the percentage area of diffuse staining increased as the degree of dysplasia progressed. Although all normal colorectal glands and most hyperplastic polyps (71.4%) showed no staining of hRFI, most colorectal adenomas and carcinomas (93.2%) showed a focal or diffuse staining (P<0.001). Furthermore, the percentage of diffuse staining in carcinomas (81.3%) was significantly higher than in adenomas (5.7%) (P<0.001). hRFI is highly expressed in colorectal carcinomas. In the adenoma-carcinoma sequence, hRFI is involved at the initial tumor formation and its diffuse expression is associated with colorectal carcinogenesis. This evidence suggests that hRFI may act as an oncogenic molecule affecting the apoptotic pathway.
Sasaki
S
S
Dept of Surgical Oncology, The University of Tokyo, Tokyo, Japan. SASAKI-1SU@h.u-tokyo.ac.jp
Watanabe
T
T
Konishi
T
T
Kitayama
J
J
Nagawa
H
H
D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D001710:Biotin / Q000737:chemistry; D015153:Blotting, Western; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology*; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D051034:Inhibitor of Apoptosis Proteins; D008297:Male; D008875:Middle Aged; D011127:Polyps; D011506:Proteins / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D002352:Carrier Proteins; D051034:Inhibitor of Apoptosis Proteins; D011506:Proteins; C461219:RNF34 protein, human; D001710:Biotin