Appraisal of multi-drug resistance function of a new gene cloned from human lung cancer cell line SPC-A-1/CDDP and identify its chromosome's locus

In the former research work, a differential-expressed gene was cloned from multi-drug resistance lung cancer cell line (SPC-A-1/CDDP) with suppression substractive hybridization, and in this study we further analyze the site of this gene on the chromosome, and appraise its function related to multi-drug resistance in lung cancer cells. The cDNA sequence data of the gene was input to computer and analyzed to ascertain its site on human chromosome by screening the gen bank on the www. ncbi, nlm. nih. gov. With DNA recombination technique, the gene was reversedly inserted to the vector pLXSN to get an antisense expression recombinant vector pLXSN-R, which was then transfected into SPC-A-1/CDDP cells with the aid of electroporation technique. And the semi-quantitative RT-PCR technique was used to quantify the mRNA content of gene in the transfected cells. Finally, the chemosensitivity of the transfected cells was tested with MTT method. The gene was located on the human chromosome 19ql3. 3 - 19ql3. 4 locus. The antisense gene recombinant vector was successfully constructed and transfected into SPC-A-1/CDDP cells as shown by its inhibitory activity on the mRNA expression of the gene. The drug-resistance indexes of transfected SPC-A-1/CDDP cells for cisplatin, doxorubicin, 5-fluorouracil, vincristin, hydroxycamptothecine and etoposide were obviously decreased. The function of this gene is related to multi-drug resistance in human lung cancer cell, and its locus on the human chromosome is at 19ql3. 3-1913. 4.