The Effect of Transfer of p21/WAF1 Gene on Kidney and Bladder Cancer Cell Lines

Bang, Jang Ho; Moon, Woo Chul

Abstract

PURPOSE: To identify antitumor effect, indication and antitumor mechanism of p21/WAF1 gene therapy in human kidney and bladder cancer.
MATERIALS AND METHODS
We cloned cDNA of wild type human p21 gene by reverse transcription-polymerase chain reaction(RT-PCR) technology and constructed a mammalian expression plasmid vector carrying cDNA of wild type human p21 and CMV enhancer/promotor(pCMV-p21). pCMV-p21 was administered in vitro in complex with HDL cationic polyliposome into human kidney cancer cells(CURC-1 and CURC-2), bladder cancer cells(RT4 and T24), and liver cancer cells(Hep3B and HepG2), followed by analysis of viable cell number, cellular morphology, cell cycle distribution and development of apoptosis.
RESULTS
The expression of p21 was preserved in p53-wild type cells and markedly decreased or absent in p53-mutant cells. Administration of pCMV-p21:HDL complex induced high level expression of p21 and significant suppression of growth in all of the cancer cells examined, regardless of their genetic status of p21 and p53. Transfer of p21 to cancer cells induced not only decrease of proportion of cells in G2+M/S phase but also apoptosis.
CONCLUSIONS
HDL cationic polyliposome-mediated p21 gene transfer may become a promising therapeutic modality for human kidney and bladder cancer and that p21 may have a novel function to induce apoptosis to human bladder and kidney cancer cells. Further studies are necessary on in vivo antitumor effect of p21 gene transfer and molecular mechanism of p21 gene-induced apoptosis.