OBJECTIVETo study effects of ectopic expression of BCSC-1 gene on the malignant activi-BCSC-1 cDNA was isolated by RT-PCR ties of human nasopharyngeal carcinoma cell CNE-2L2.

METHODSand inserted into pMAL-c2X and pcDNA4/myc-His A. BCSC-1 protein was expressed in prokaryocytes. Rabbit antiserum to BCSC-1 was developed by means of immunization of rabbit with the BCSC-1 protein. Expression of BCSC-1 gene in wild type CNE-2L2 cell (W cell) was examined by real-time RT-PCR and immunofluorescence staining with the antiserum as a probe. pcDNA4/myc-His A-BCSC-1 was transfected into W cell at the presence of LipofectAmine. The cells were selected by G418 and cloned. Ectopic expression of BCSC-1 gene in W cell was examined by Western blot. Cell growth was detected by drawing of growth curves and colony formation tests. Cells were inoculated into nude mice. Size of tumors was assayed once a week. Lungs of the mice were sectioned continuously and metastatic loci in lungs were examined upon a microscope.

RESULTSRabbit BCSC-1 antiserum was prepared. Expression of BCSC-1 gene in W cell was found to be very low. CNE-2L2 cell with ectopic expression of BCSC-1 gene was developed. Growth in vitro, colony formation, tumorigenesis in nude mice, and lung metastasis of the tumor were profoundly inhibited of the cell with ectopic expression of BCSC-1 gene in comparison with controls, wild type cell and the cell transfected with mock. Conclusion Ectopic expression of BCSC-1 gene exerts profound inhibitive effect on the malignant activities of CNE-2L2 cell.