Antisense p53 provokes changes in HeLa cell growth and morphology.

Human cervical carcinoma HeLa cells, containing the wild-type p53 protein, were stably transfected with a p53 antisense encoding plasmid. Differences in the p53 content in extracts from the p53 antisense transfected HeLa clones compared to the parental HeLa cells were demonstrated by protein binding to the p53 consensus oligonucleotide and in transactivation assays. Striking morphological alterations were observed in several HeLa clones stably transfected with the p53 antisense encoding plasmid. Giant multinucleated cells appeared several passages after transfection in four p53 antisense transfected HeLa clones derived from three independent transfection experiments, and were not observed in parental HeLa cells, or in p53 sense or vector-transfected HeLa clones. A strong growth inhibitory effect was observed for the HeLa clones stably transfected with p53 antisense encoding plasmid. Reconstitution experiments with HeLa cells treated with a short p53 antisense oligonucleotide gave similar results: growth inhibition and giant cells. These giant multinucleated cells were negative for [3H]thymidine incorporation and displayed dispersed nuclear staining for proliferating cell nuclear antigen, indicating the absence of DNA replication.