Growth inhibition of cancer cells by co-transfection of diphtheria toxin A-chain gene plasmid with bovine leukemia virus-tax expression vector.
We constructed a plasmid containing bovine leukemia virus (BLV)-tax gene driven by SR alpha promoter, designated as pME-BLVtax, to activate the promoter of the long terminal repeat (LTR) of BLV in various tumor cells. Activation of the promoter of BLV-LTR by pME-BLVtax was confirmed by luciferase assay. When the cells, such as COS-1, C8, and KU-1, were transfected with a plasmid pBLV-LUC1, which contained the luciferase gene under the control of BLV-LTR, and pME-BLVtax, luciferase was expressed in these cells, whereas no luciferase gene expression was observed when only pBLV-LUC1 was introduced into the cells. Activation of the BLV-LTR promoter was regulated by pME-BLVtax and 0.5 microg of pME-BLVtax was sufficient for the expression of the gene under the control of BLV-LTR. Furthermore, pME-BLVtax was used to direct the cell expression of the gene for diphtheria toxin A-chain under the control of BLV-LTR (pLTR-DT) to various tumor cell lines, KU-1, C8, COS-1, BL2M3, and HeLa cells. The transfection was carried out with cationic liposomes. In this experiment, co-transfection of pLTR-DT with pME-BLVtax exerted selective growth inhibitory effects on the tumor cell lines. Moreover, three co-introductions of pLTR-DT with pME-BLVtax into the cell lines resulted in significant inhibition of the cell growth. This result suggests that the delivery of the pLTR-DT and pME-BLVtax genes into tumor cells by the use of cationic liposomes may be potentially useful as a novel approach for the treatment of tumor cells.
Tana
Division of Veterinary Science, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Sakai, Japan.
Watarai
S
S
Aida
Y
Y
Tajima
S
S
Kakidani
H
H
Onuma
M
M
Kodama
H
H
D000818:Animals; D019556:COS Cells; D002461:Cell Line, Transformed; D004167:Diphtheria Toxin / Q000235:genetics*; D016355:Genes, pX; D015316:Genetic Therapy; D005822:Genetic Vectors; D006367:HeLa Cells / Q000473:pathology*; D006801:Humans; D001909:Leukemia Virus, Bovine / Q000235:genetics*; D008156:Luciferases / Q000235:genetics; D010957:Plasmids; D011401:Promoter Regions, Genetic; D014162:Transfection
D004167:Diphtheria Toxin; D008156:Luciferases