We attempted to develop a new strategy of gene transfer in human metastatic cells avoiding viral vectors. We demonstrated the feasibility of the nlsLacZ gene-liposome (DOTAP) complex transfection in lung cancer cell lines H358 and Calu-1 carrying homozygous deletion of p53 and in primary cultures of human pleural metastatic tumor cells (n = 10). The efficiency of transfection in pleural cells was high with a mean of 78 +/- 22% (range 40-100%) compared to H358 (30%) and Calu-1 cells (50%). In this study, we report that growth of pC53-SN3-transfected Calu-1 and pleural metastatic cells was greatly suppressed whereas neither liposomes or Neo-gene affected cells growth. We tempted to determine whether restoration of wtp53 increased the chemosensitivity of cells that normally lack p53 expression. The pC53-SN3 transfected cells (H358 and Calu-1) were more sensitive to CDDP than the parental cells by 14 and 1.2 fold, respectively. In addition, the sensitization ratio due to the transfection of wtp53 in pleural cells (n = 6) varied from 1.2 to 6 fold. This sensitization remained even 21 days after transfection and was accompanied by increase of p53 positive cells and of the proportion of apoptotic bodies. In conclusion our results suggested that DOTAP is an efficient vector for mediating gene transfer in pleural metastatic cells offering advantages compared to viral vectors, while tumor suppressor genes such as p53 may be good candidates in combination with conventional therapy with CDDP that could be further developed for their use in local cancer gene therapy.