Treatment of experimental tumors with a combination of a pulsing magnetic field and an antitumor drug.
We investigated the effects of a combination treatment involving a pulsing magnetic field (PMF) and an antitumor drug, mitomycin C (MMC), on two experimental tumors (fibrosarcoma KMT-17 and hepatocellular carcinoma KDH-8) in WKA rats, paying attention to possible potentiation of the therapeutic effect of the antitumor drug. PMF was obtained using a system generating a pulsed current in a solenoid coil. On day 7 after tumor implantation into the right thighs of rats, the region of the tumor was exposed to PMF (frequency 200 Hz, mean magnetic flux density 40 gauss) for 1 h immediately after iv injection of MMC at a dose of 1 mg/kg. Survival rates at day 90 of KMT-17 implanted rats were 0% (0/10) in the non-treated group, 34% (4/12) in the MMC-treated group, 47% (6/13) in the PMF-treated group and 77% (10/13) in the MMC/PMF combination group. The increase of life span (ILS) of KDH-8-implanted rats in the combination therapy group was significantly prolonged (%ILS 17.6%) compared with that in the MMC-treated (%ILS 3.4%) and PMF-treated (%ILS 7.6%) groups. By using cultured cells of the above two lines of tumor, the therapeutic effects of MMC and PMF were also determined from the cell colony-forming efficiency in soft agar. The colony-forming efficiencies of both cell lines were significantly suppressed in the combination therapy group compared with those in the other single therapy groups. The present results indicate that PMF exhibited a potentiation of the antitumor effect of mitomycin C.
Omote
Y
Y
Laboratory of Pathology, Hokkaido University School of Medicine, Sapporo.
Hosokawa
M
M
Komatsumoto
M
M
Namieno
T
T
Nakajima
S
S
Kubo
Y
Y
Kobayashi
H
H
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D002455:Cell Division / Q000187:drug effects; D003131:Combined Modality Therapy; D005354:Fibrosarcoma; D006358:Hot Temperature; D066298:In Vitro Techniques; D008280:Magnetics; D008297:Male; D016685:Mitomycin; D008937:Mitomycins / Q000008:administration & dosage; D010507:Periodicity; D051381:Rats; D011919:Rats, Inbred Strains; D012513:Sarcoma, Experimental / Q000628:therapy*; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D008937:Mitomycins; D016685:Mitomycin