the expression of heme oxygenase-1 in human-derived cancer cell lines

background: heme oxygenase-1 (ho-1) is a cytoprotective and antiapoptotic enzyme, which has been involved in maintaining cellular homeostasis, and plays an important protective role by modulating oxidative injury. up-regulation of (ho-1) has contributed to tumorogenicity of some cancers. in this study we investigated the expression pattern of the ho-1, in five different human-derived cancer cell lines with high incidence in iran. methods: total cell rna were extracted from hepg2 (hepato carcinoma), a549 (lung adenocarcinoma), mcf-7 (breast cancer), k562 (myeloid leukemia) and ls174t (colon cancer) cell lines. human embryonic kidney (hek293) cell line was used as a control. cdnas were synthesized and expression of ho-1 was examined using rt-pcr. results: the expression of ho-1 was not detected in the control cell line (hek293), but it was observed to express following ultraviolet (uv) exposure indicating that ho-1 is not constantly expressed. the examined cancer cell lines constitutively expressed different variety of ho-1 on mrna level. strong expression of ho-1 was observed in hepg2, mcf-7 and a549 cells. a moderate expression of ho-1 was observed in k562 cells, and ls174t cells showed no expression of ho-1. conclusion: heme oxygenase-1 could be considered as a new marker in the diagnosis of some cancers, especially hepatomacarcinoma. our results also suggest that up-regulation of ho-1 may contribute to tumorogenicity of some cancers. therefore, the combination of gene-silencing effect of ho-1 and chemotherapy might be considered as a new modality for the treatment of cancers in which the expression ho-1 is up-regulated.