Expression of Myc target gene mina53 in subtypes of human lymphoma

Abstract

Mina53 (mina) was identified as a gene, which is directly induced by the oncogene c-myc. Elevated expression of Mina53 protein was found in >80% of colon cancer and esophageal squamous cell carcinoma (ESCC). Patients with high expression of Mina53 had shorter survival, suggesting the prognostic usefulness of Mina53. We studied Mina53 expression in lymphoma subtypes to examine its diagnostic significance and its possible role in lymphoma-genesis. Surgical cases of 28 lymphoma and 4 non-neoplastic tissues were stained immunochemically using anti-Mina53 monoclonal antibody. Mina53 expression correlated well with c-Myc expression in lymphoma, suggesting that c-Myc is a controlling factor for mina53 expression also in lymphomas. Although the expression of Mina53 as well as c-Myc was less frequent in lymphoma compared with those of colon and ESCC, increased expression of Mina53 was found in Burkitt-like lymphoma (1/1), Hodgkin's lymphoma (3/5), diffuse large B cell lymphoma (DLBCL) (5/13), lymphomas with a transition from follicular to DLBCL (1/2), with none in follicular (0/4) and T cell lymphoma (0/3). Analyses of the data suggested that Mina53 was frequently expressed in aggressive types of B cell lymphoma. To get more information about the expression of Mina53 in DLBCL, which most frequently occurs among lymphomas, we analyzed the expression of Mina53 in another 21 DLBCL specimens, which were in more advanced stages than those described above. The expression level of Mina53 correlated to the international prognostic index (IPI) values with statistical significance (r=0.477, P=0.0275). Notably, in this group, Mina53 expression did not correlate with c-Myc expression, suggesting that other factor(s) besides c-Myc largely affect the expression of Mina53 in advanced DLBCL. These results suggest that although Mina53 expression is not prominent in lymphoma in general, it may be related to tumor progression of B cell lymphoma.