The Role of Heme Oxygenase -1 System in Melanoma Tumor Growth of C57Bl/6 Mice

Some evidence about the relationship between heme oxygenase and many cancers is available. Heme oxygenase has anti-apoptotic effects and contributes to tumor growth. The aim of this study was to evaluate the effect of heme oxygenase on melanoma tumor cells mitosis and tumor size in C57BL/6 mice. B16F10 melanoma cells were injected subcutaneously to 18 C57B 6 mice with 8 weeks of age. Mice were randomly divided into three groups: the first group received Zinc protoporphyrin (Znpp), heme oxygenase inhibitor (n = 6), the second group, hemin (heme oxygenase activator) (n = 6) and the third group((control group) (n = 6)) received diluent injection. They received their injection every other day from the first day of study for 16 days. Tumors were extracted in the 16th day of study. Length and width of tumors were measured and mitotic cell activities were evaluated using immunohistochemistry staining and counting Ki-67 posetive cells. Our study results showed that size and weight of tumor and mitotic index in treated mice by Hemin were higher than two other groups. (P≤0.05). But mitotic index, tumor size and tumor weight in the recipient Znpp group and the control group were not statistically different. Stimulation of Hemeoxygenase-1 pathway by hemin injection can increase melanoma tumor growth. However, inhibition of this pathway by Hemeoxygenase -1 inhibitors may not be effective in reducing tumor growth and size.