A two- to fourfold higher expression of CEA mRNA (3.6 kb) was observed in 11 of 22 colorectal tumors (2 of 9 proximal colon tumors and 9 of 14 rectosigmoid tumors) when compared with morphologically normal adjacent mucosae.
The APC gene is responsible for familial adenomatous polyposis and is considered to be a tumor suppressor gene associated with development of sporadic colorectal tumors.
In the present study, LOH at the DCC locus on chromosome 18q and the expression of DCC gene into mRNA were analyzed in colorectal tumors with distinct histopathological types.
HT29 cells weakly expressed IGF-II mRNA in comparison with the high over-expression previously observed in some colorectal tumors, and only the 4.8-kb mRNA species was present.
Although gastrin mRNA has been demonstrated to be present in colon cancer cell lines, the intact peptide had not been recovered from human colorectal neoplasms.