HEME OXYGENASE-1 EXPRESSION IN HUMAN TUMORS.

GANDINI AN; LANG C,; FIORE L; FERMENTO ME; MATURI H; FACCHINETTI MARIA M; CURINO ALEJANDRO C

Mar del Plata

Congreso; 43 Reunion Anual de la Sociedad Argentina de Investigacion en Bioquimcia y Biologia Molecular; 2007

Sociedad Argentina de Investigacion en Bioquimcia y Biologia Molecular

Heme oxygenase-1 (HO1) enzyme is responsible of catalyzing the rate-limiting step in heme catabolism. However, it has been very recently suggested to be involved in oncogenesis both as a promoter and as an inhibitor of tumor progression. Thus, it has been shown to transform cells in culture and to induce tumor formation in a mouse model of Kaposi Sarcoma. It has also been shown that its expression levels are associated with a better survival in colorectal cancer. Most of the data has been obtained mainly by using mouse models of cancer and cell lines. Little work analyzes protein expression in human tumors. Therefore, we focused on studying protein expression in various human tumors. We first performed a screening of HO1 expression in HNSCC samples by using the recently developed tissue array: we observed that the enzyme was expressed in   79% of tumors. To obtain more qualitative information we studied angiosarcomas, head and neck squamous cell carcinomas (HNSCC), gliomas, breast and colorectal carcinomas by immunohistochemistry and observed that the staining was stronger in tumor cells when compared with adjacent tissue. Staining was cytoplasmic for all the specimens assayed except for gliomas where nuclear staining was also observed. In a glioma-derived cell we observed nuclear staining as well. The results shown confirmed that HO1 may play a role in human tumor progression.