THE EFFECT OF GENTAMICIN ON THE GROWTH OF B16F10 MELANOMA CELLS IN C57BL/6 MICE

Abstract

The anti-tumor effect of bacteria/bacterial products have been observed and reported for over a hundred years. Yet, the increased use of antibacterial agents might alter the normal microbial flora, resulting in the eradication of microorganisms that might be controlling tumor growthand /or affect levels of tumor promoting factors. In this study, the effect of gentamicin on the survival of C57BL/6 mice bearing the B16F10 melanoma cells was assessed and the serum levels of Nitric Oxide (NO) and Vascular Endothelial Growth Factor (VEGF) were determined. Groups of C57BL/6 mice were challenged with the B16F10 melanoma cells and were given a daily dose of pyrogen-free saline (control) or Gentamicin administered intraperitoneally (IP) for a period of 10 days. At day 10 post-treatment, mice from each group were bled; the serum was collected and used to determine NO levels using the Griess reagent system and VEGF levels using the enzyme-linked immunosorbent assay (ELISA). Remaining mice in each group were monitored for ten days for survival rate assessment. After receiving gentamicin intraperitoneally (IP), the serum levels of NO significantly decreased 1 hour after the last dose of gentamicin then increased 3 hours after the last dose of gentamicin was given. The levels of VEGF significantly increased after IP doses of gentamicin. In the saline control group, 66.66% of the tumor-bearing mice survived, yet none of the mice in the group treated with IP gentamicin survived (0% survival). Gentamicin appears to promote growth of the B16F10 tumor in mice. Probably because it modifies the normal microbial flora, of which some members are involved in preventing the establishment of the tumor, and/orits effect on the serum levels of NO and VEGF.

Key words: B16F10 melanoma cells, Gentamicin, Nitric Oxide, VEGF