Cell-specific expression of the diphtheria toxin A-chain coding sequence induces cancer cell suicide.
OBJECTIVE
To test whether the diphtheria toxin A (DT-A) chain coding sequence linked to murine immunoglobulin Kappa light chain (IgKappa) promoter and enhancer have selective cytocidal effects on IgKappa producing cells.


METHODS
The diphtheria toxin A gene or beta galactosidase (beta-gal) gene were linked to a murine IgKappa promoter and enhancer to construct pcDNA3IgKappaDTA or pcDNA3IgKappaLacZ plasmids. These plasmids were transfected into IgKappa producing or non-producing cells by the liposome coated DNA method. Expression of beta-gal activity and effects on cell growth of transfected cells were assessed.


RESULTS
The beta-gal gene, under the control of cytomegalovirus (CMV) promoter, can express in all cell lines. Expression of beta-gal under the control of the IgKappa promoter was detected only in the IgKappa producing cell line, CA46. Expression of beta-gal was greatly suppressed when cotransfected with pcDNA3IgKappaDTA in CA46 cells. Cell growth of CA46 cells transfected with pcDNA3IgKappaDTA plasmid was significantly inhibited compared with CA46 cells transfected with pcDNA3IgKappaLacZ.


CONCLUSIONS
Selective killing of IgKappa producing cells can be attained by introducing the diphtheria toxin A gene under the control of IgKappa promoter and enhancer.
Rui
Hongbing
H
Fujian Institute of Hematology, The Union Hospital, Fujian Medical University, Fuzhou 350001, China.
Chen
Yuanzhong
Y
D004167:Diphtheria Toxin / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D005803:Genes, Immunoglobulin; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D009369:Neoplasms / Q000628:therapy*; D010446:Peptide Fragments / Q000235:genetics*; D011401:Promoter Regions, Genetic; D014407:Tumor Cells, Cultured
D004167:Diphtheria Toxin; D007145:Immunoglobulin kappa-Chains; D010446:Peptide Fragments; C029795:diphtheria toxin fragment A