Accelerated expression of a Myc target gene Mina53 in aggressive hepatocellular carcinoma

Aim: Expressions of the myc target genes Mina53 and mimitin are high in esophageal squamous cell carcinoma and colon cancer, and their relationship to cell proliferation and patient prognosis has been reported. Because c-myc gene expression is closely related to hepatocellular carcinoma (HCC) growth or formation and/or maintenance, we examined the Mina53 and mimitin expressions in HCC. Methods: Surgically resected 53 HCC tissues were immunohistochemically examined for Mina53 and mimitin expressions and their relationship to clinicopathological factors. Results: Diffuse Mina53 expression was observed in the nuclei of cancer cells in the tumor nodule, but was often strong at the periphery of tumor nodules. Diffuse or scattered expression of mimitin was observed in the cytoplasm of HCC cells in tumor nodules. Mina53 expression was higher in poorly differentiated HCC than in well-differentiated HCC, and significant relationship to histological grade was observed. The cases with a high Mina53 expression also had a high expression of a proliferation marker MIB-1. This suggested the involvement of Mina53 in cell proliferation. Mina53 expression was high in the tumors of > 2 cm of diameter than in < 2 cm (P < 0.01). Mimitin expression tended to be high in tumors of > 2 cm, but no significant relationship was observed either to histological grade, MIB-1 expression, or the other clinicopathologic factors. Conclusions: Our findings suggested that Mina53 expression is accelerated in HCC with a lower histological grade, with cell proliferation capability, or with a larger diameter, and Mina53 is related to biological malignancy of HCC.