Expression of Id3 in A549/DDP cells and its significance

Objective: The Id proteins,also referred to as inhibitors of differentiation,express abnormally in a variety of human tumors and participate in the proliferation,differentiation and apoptosis of tumorous cells.We designed our study to investigate the expression of Id3 in Cisplatin resistant human lung adenocarcinoma A549/DDP cells in vitro and its significance.Methods: We constructed the recombinant eukaryotic expression vector Id3/pEGFP containing human Id3 cDNA and EGFP fusion genes,and transfected them into A549/DDP cells by the liposome-mediated method.After the transfection,we observed the EGFP expression by fluorescent microscopy,detected the alteration of the Id3 expression by semi-quantitative RT-PCR,and determined cell proliferation and inhibition by MTT assay.Results: The human eukaryotic expression vector Id3/pEGFP was successfully constructed and transfected into A549/DDP cells.RT-PCR showed that Id3 mRNA was effectively expressed in the Id3/pEGFP-transfected A549/DDP cells,and the growth of these cells was significantly inhibited.Conclusion: The transfected Id3/EGFP fusion genes can be effectively expressed in A549/DDP cells,and the exogenous Id3 gene can suppress the proliferation of these cells.