Раковая наука и терапия

Host H67D Genotype Affects Tumor Growth in Mouse Melanoma

Abstract

Cody Weston, William Hund, Anne Nixon, Elizabeth Neely, Becky Webb, Ahmed Alkhateeb and James Connor

Background: We investigated the effects of the frequently polymorphic high iron gene (HFE), on tumor growth in a novel mouse model. We hypothesized that host mutations in the HFE protein modify tumor progression.

Methods: C57BL/6 mice possessing either H67D/H67D or WT/WT HFE genotype, aged 18 months, were injected subcutaneously with 4x106 cells of the B16F10 mouse melanoma cell line. After 2 weeks, mice were sacrificed and the tumors and plasma were collected. Animal methods were approved by our IACUC, (04-166). Tumors were analyzed by RT-PCR. In parallel, bone marrow derived macrophages were cultured to determine how B16F10 cell cultures react to conditioned media from macrophages of each genotype. ELISAs were performed for ferroportin, ferritin, secreted cytokine and chemokine content of macrophage media. Results: H67D mice had significantly smaller tumors (t-test, P = 0.02) after two weeks. Exploratory qRT-PCR analysis of tumors revealed that the H67D host may suppress angiogenesis and growth. In culture, macrophages derived from H67D mice secrete higher levels of monocyte chemoattractant protein 1 (MCP1), suggesting a change in chemotactic signaling (p = 0.02). When conditioned media from the H67D macrophages were placed onto B16F10 cells in culture there was significantly less growth compared to conditioned media from WT macrophages (p < 0.01 MTT, p < 0.01 BrdU). In macrophage cell lysates, H67D is associated with lower levels of Ferroportin (p = 0.03). Conclusions: Macrophages from H67D mice do not support tumor cell proliferation as well as WT controls. Our data reveal the importance of HFE genotype on tumor growth that may be related to macrophage function.