Cell-specific expression of the diphtheria toxin A-chain coding sequence induces cancer cell suicide / 中华医学杂志(英文版)

ABSTRACT

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>Selective killing of IgKappa producing cells can be attained by introducing the diphtheria toxin A gene under the control of IgKappa promoter and enhancer.</p>