Increased expression of FAT10 in colon benign, premalignant and malignant epithelial neoplasms

The overexpression of FAT10 is characteristic of numerous types of carcinoma including liver, gastric and colon carcinomas. In the case of colon carcinoma it is possible to determine the point in the progression from the benign to the malignant process of colon cancer development by determining which stage in the neoplastic process FAT10 overexpression occurs. This stage was determined by measuring the intensity of fluorescence of immunohistochemically stained normal mucosa, tubular adenomas, hyperplastic polyps, serrated adenomas, villotubular, villous adenomas and invasive adenocarcinoma stages. Using this approach it was found that the overexpression of FAT10 began at the serrated adenoma stage and continued to include the villous and villotubular stages and the invasive adenocarcinoma stage. The FAT10 overexpression by invasive adenocarcinoma was accompanied by the expression of the catalytic subunits of the immunoproteasome which is functionally tied to the overexpression of FAT10, Toll-like receptor activation and the proinflammatory response.