In vivo antitumor effects of electrochemotherapy in a tongue cancer model.
OBJECTIVE
This study investigated the in vivo antitumor effects of electrochemotherapy (ECT) using electroporation and bleomycin in a hamster tongue cancer model to assess its clinical applicability.


METHODS
Twenty animals with chemically induced tongue cancer were divided into four experimental groups designated B-E-, B-E+, B+E-, and B+E+. The B+E+ and B+E- groups received an intraperitoneal injection of 100 microg bleomycin. Fifteen minutes after the injection, the B+E+ animals received electric pulses. The B-E+ group received only electric pulses. The B-E- group received neither bleomycin nor electric pulses. Each group received the same treatment twice. The antitumor effects were assessed based on tumor volume reduction and histologic findings.


RESULTS
The B+E+ group showed remarkable tumor volume reduction, decreasing an average to 8.8% of its original volume 14 days after the treatment. Complete loss of the protruding tumor was observed in two of the five animals. Histologically, the tumors of the B+E+ group consisted of severely degenerated tumor cells and desquamative keratinizing cells. No living cancer cells were detected in three animals. The B+E-, B-E+, and B-E- groups showed progressive tumor growth, exceeding 200% of initial tumor volume during the experimental period.


CONCLUSIONS
The current study showed remarkable antitumor effects of ECT with bleomycin in the hamster tongue cancer model. ECT with bleomycin may be clinically applicable to the treatment of oral cancer.
Omura
S
S
Department of Oral and Maxillofacial Surgery, Yokohama City University School of Medicine, Japan. sos3728@med.yokohama-cu.ac.jp
Tsuyuki
Y
Y
Ohta
S
S
Bukawa
H
H
Fujita
K
K
D015127:9,10-Dimethyl-1,2-benzanthracene; D000704:Analysis of Variance; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage*; D001761:Bleomycin / Q000008:administration & dosage*; D002273:Carcinogens; D003131:Combined Modality Therapy; D006224:Cricetinae; D004195:Disease Models, Animal; D004354:Drug Screening Assays, Antitumor; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D018274:Electroporation; D008297:Male; D008647:Mesocricetus; D014062:Tongue Neoplasms / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology
D000903:Antibiotics, Antineoplastic; D002273:Carcinogens; D001761:Bleomycin; D015127:9,10-Dimethyl-1,2-benzanthracene