Minimal expression of the proto-oncogene int-2 encoded protein in a series of colorectal carcinomas

Background:Int-2 (fibroblast growth factor-3) is a gene that belongs to the fibroblast growth factor gene family. It has been implicated in the carcinogenesis of several types of cancer, including esophageal squamous cell carcinoma, breast, head, and neck and lung carcinomas; but no firm data on its biological activity regarding neoplasms arising from the glandular epithelia of the gastrointestinal tract exists. Methods: In the present immunohistochemical study, we investigated the presence of int-2 encoded protein in a panel of 80 cases of colon carcinoma of various stages, grades and sizes. A sheep antihuman int-2 antibody was applied to paraffin-embedded tissue sections from the tumor samples. The percentage of int-2 immunostaining in the positively stained specimens was evaluated by image analysis. Results:Int-2 was positively detected in only four tumors (i.e. 5% of the cases examined). All immunopositive cases were moderately differentiated tumors; the adjacent mucosa did not express int-2 protein. The relevant patients were male. Conclusion: These findings suggest that the role of int-2 in colorectal carcinogenesis is probably a limited one.