Effect Of Exogenous Wild P53expression On Sensitization To Chemotherapeutic Agents In Human Lungl Cancer Cells And Cloning Of Related Genes

To investigate the effects of exogenous wtp53 expression on sensitization to chemotherapeutic agents with different mechanism of action in human lung cancer cells and clone the related genes induced by wtp53.A human lung cancer cell line 801-D with point mutation of p53 was transfected with either constructed plasmid pEGFP p53 or pEGFP by lipofection named 801-Dwtp53 and 801-Dvector which expresses wtp53 or pEGFP vector . The exists of neo and wtp53 gene in anti-G418 801-D clone, 801-Dvector and 801-Dwtp53 were detected by PCR.The function activity of transfected \vtp53 were demonstrated by partly 801-D apoptosis.3H-TdR uptake assay was taken for drug sensitivity measure according to standard procedures. 801-D cell line shows a selective sensitization to DNA-damaging agents when exogenous wtp53 is expressed. The results indicated p53 dependent sensitization to Cisplatin (9.7-fold) and 5-Fu (11.4-fold) in 801-Dwtp53 compared to 801-Dvector.There are no significant difference for other DNA-damaging agents.The increased sensitization to Cisplatin by exogenous wtp53 expressition through no-apoptosis pathway. There were no down-regulation of MDR1 expression by wtp53.Three RNA populations were subjected to screening by the differential displaymethod, matched RNA sample from 801-Dwtp53 and 801-Dvector inducedbyCisplatin.We got six differentially hight expressed transcripts from Cisplatin induced801-Dwtp53 . After sequencing and nucleodide predicted sequencing, We found oneof them has an ORF encoding 46 residues which was 56% homologous with ribonucleoside-diphosphate reductase A, this suggest the fragment probably get involved the Cisplatin sensitively of 801-D modulated by wtp53.