2011 Volume 60 Issue 2 Pages 101-109
To investigate the usefulness of the immunopotentiator from Pantoea agglomerans 1 (IP-PA1) as a supportive drug in melanoma therapy, we analyzed the immunological effects of IP-PA1 on melanoma-inoculated model mice. Oral administration of IP-PA1 increased the serum levels of tumor necrosis factor (TNF)-α at 2 h after the administration and interferon (IFN)-γ and IL-12 at 12 h after the administration in naïve BALB/cCrSlc mice as evaluated by ELISA. IP-PA1 did not affect the proliferation of melanoma cells directly determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Combinatory treatment of IP-PA1 with doxorubicin for 9 days increased the serum levels of IFN-γ and IL-12 by 71.0 and 15.3%, respectively, compared to the treatment of doxorubicin alone in melanoma-bearing C57BL/6NCrSlc mice as evaluated by ELISA. It also increased the proportion of natural killer (NK) cells and the ratio of CD4+ to CD8+ T cells in the spleen from 6.1 ± 0.3 to 7.4 ± 0.5% and from 1.25 ± 0.03 to 1.38 ± 0.04, respectively, compared to the treatment of doxorubicin alone as analyzed by flow cytometry. The mean survival period of melanoma-bearing, doxorubicin treated mice was prolonged from 31.4 ± 7.1 to 35.3 ± 8.4, 51.1 ± 5.4, and 45.0 ± 8.4 days by combinatory treatment of IP-PA1 at the daily doses of 0.1, 0.5, and 1 mg/kg, respectively. In conclusion, the results of the present study suggest the usefulness of IP-PA1 as a supportive drug in melanoma therapy.
Bulletin of the Experimental Animals
Proceedings of The Japanese Association of Animal Models for Human Diseases
Proceedings of The Japanese Society of Animal Models for Human Diseases
