Proliferation Inhibition of Human Cancer Cells in Combined Use of Electroporation with Attenuated Diphtheria Toxin

Abstract

Attempts to cause temporary pore formation of cancer cell membrane and to introduce intracellulary attenuated diphtheria toxin (fDT) following treatment with formaldehyde were performed utilizing high-voltage electric pulses. Human pancreatic cancer cell line (ASPC-1) and lung cancer cell line (PC9) were electroporated in the presence or the absence of fDT. Almost complete inhibition of target cell proliferation was observed when the cells were electroporated (90 V, 10 ms, n = 8) in the presence of fDT, even after washing. Similar marked inhibition of PC9 cell proliferation was obtained when anti-DT antibodies were added after electroporation (EP) instead of washing. These results indicate that the presence of fDT is needed only during the time of EP treatment and the side-effects of the agents can be avoided by specific antibodies.