Exogenous expression of p21(WAF1/CIP1) exerts cell growth inhibition and enhances sensitivity to cisplatin in hepatoma cells

The effects of exogenous expression of p21(WAFI/CIPI) in hepatoma cells wer e examined. Two stably p21(WAFI/CIPI)-transfected clones and one clone tran sfected with expression vector only were used for study. Introduction of p2 1(WAFI/CIPI) resulted in significant cell growth inhibition, and the magnit ude of the cell growth inhibition in these transfected cells was proportion al to the level of p21(WAFI/CIPI) protein expressed. Exogenous p21(WAFI/CIP I) expression also significantly enhanced chemosensitivity to cisplatin. In addition, apoptosis occurred earlier in cells transfected with p21(WAFI/CI PI) after cisplatin treatment. These findings raise the potential that forc ed upregulation of p21(WAFI/CIPI) in hepatocellular carcinoma (HCC) may red uce the doses of cisplatin to achieve similar responses and suggest the pos sible use of p21(WAFI/CIPI) in HCC treatment. (C) 2001 Elsevier Science Ire land Ltd. All rights reserved.