[The study of P68 RNA helicase on cell transformation]

The P68 nuclear protein is an ATP-dependent RNA helicase and RNA-dependent ATPase, and has been proved to have functions in the regulation of cell growth and division. Different phenotypes of P68 between tumouric cell lines (HeLa, TC3H10) and non-tumouric cell lines (NIH3T3 and NC3H10) were observed, and we reasoned that overexpression of P68 might profoundly affect cellular growth properties. We report here that overexpression human P68 by transfection of recombinant P68 expression vector in NIH3T3 and NC3H10 fibroblasts causes their tumorigenic transformation as determined by four criteria: (1) the morphology of transfectants from long fibric to spindle shaped; (2) formation of transformed foci on the monolayer of cells; (3) the transfectants acquired the ability to grow on soft agar forming cell microsphere cube; (4) tumor formation in nude mice after injection of transfected cells for 3-4 weeks.