Overexpression of rck/p54, a DEAD box protein, in human colorectal tumours

The RCK gene is a target of the t(11;14)(q23;q32) chromosomal translocation observed in human B-cell lymphoma, and the overexpression of its protein ( rck/p54) by the translocation was shown to cause malignant transformation. The rck/p54 protein belongs to the DEAD box protein/RNA helicase family, wh ich has a variety of functions such as translation initiation, pre-mRNA spl icing and ribosome assembly. The expression of rck p54 in colorectal adenoc arcinoma cells was examined by immunohistochemistry and Western blot analys is. The rck/p54 protein was found to be overexpressed in tumour tissues res ected from 13 (50%) out of 26 cases of colorectal adenocarcinomas and two o ut of two (100%) cases of colonic severe dysplastic adenomas. In view of ac tivities of rck/p54 determined in other tissue types, we suggest that rck/p 54 may contribute to the cell proliferation and carcinogenesis at the trans lational level in the development of colorectal tumours.