Expression of TGF-β1 and TGF-β R II in colorectal adenomas of varying stages

To study the function of transforming growth factor β1 (TGF-β1) and transforming growth factor-β type II receptor (TGF-βR II) in varying stages of colorectal adenoma during neoplastic transformation, fiftyfive cases of resected colorectal adenomas were examined immunohistochemically. Our results showed that the expression of TGF-β1 ranged from high to low, with the progression of low-grade to high-grade dysplasia of adenomas to carcinoma. And there was significantly different expression of TGF-β1 between moderate and high dysplasia adenomas (P<0.05), but no significantly different expression of TGF-β R II was found among varying stages of adenomas. Our results suggested that the quantities of TGF-β1 secreted by adenoma cells decrease dramatically in moderate to severe dysplasia colorectal adenomas. It is the decreased secretion of TGF-β1, rather than the mutated TGF-βR II that may play an important role in transforming colorectal adenomas to adenocarcinomas.