A potential approach for electrochemotherapy against colorectal carcinoma using a clinically available alternating current system with bipolar snare in a mouse model.
BACKGROUND
Although electrochemotherapy appears promising for the treatment of superficial tumors, its usefulness against internal tumors, such as colorectal carcinoma (CRC), has not been well examined. Furthermore, since direct current electric pulses have been used for electropermeabilization of tumors in all in vivo electrochemotherapy studies, including clinical trials, the usefulness of alternating current systems has not been examined at all. In a mouse model it was examined whether the alternating current system with a bipolar snare, which has been employed already as a clinical endoscopic treatment modality, was useful for electrochemotherapy against CRC.


METHODS
Murine CRC colon 26 cells were implanted subcutaneously into syngeneic BALB/c mice and electrochemotherapy with bleomycin (BLM) using the alternating current system was performed against established CRC tumors.


RESULTS
Electrochemotherapy significantly suppressed the growth of established CRC tumors, resulting in significantly prolonged survival of animals with CRC. Histological examination revealed that electrochemotherapy caused massive necrosis of CRC tumors. Subsequent analysis revealed that the delivery of alternating current electric pulses to CRC tumors profoundly increased intratumoral amounts of BLM.


CONCLUSIONS
Because the alternating current system using a bipolar snare has been used widely as an endoscopic treatment modality in clinical settings, these results indicate that electrochemotherapy using the alternating current system may be a promising approach for the treatment of CRC.
Kuriyama
S
S
Third Dept. of Internal Medicine, Nara Medical University, Kashihara, Japan.
Tsujinoue
H
H
Toyokawa
Y
Y
Mitoro
A
A
Nakatani
T
T
Yoshiji
H
H
Tsujimoto
T
T
Fukui
H
H
D000230:Adenocarcinoma / Q000628:therapy*; D000704:Analysis of Variance; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D001761:Bleomycin / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000628:therapy*; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D009374:Neoplasms, Experimental; D011336:Probability; D012016:Reference Values; D015996:Survival Rate; D016896:Treatment Outcome
D000964:Antimetabolites, Antineoplastic; D001761:Bleomycin