Assessment of the Selenoprotein M (SELM) over-expression on human hepatocellular carcinoma tissues by immunohistochemistry

Selenium is an essential trace mineral of fundamental importance to human healthy and exerts its biological function through selenoproteins. In particular, Selenoprotein M (SELM) is located in the endoplasmic reticulum and contains the common redox motif of cysteine-X-X-selenocysteine type. It attracts great attention due to its high expression in brain and its potential roles as antioxidant, neuroprotective, and cytosolic calcium regulator. Recently, our group found SELM over-expression  in human hepatocellular carcinoma (HCC) cell lines. In this report some paraffin-embedded tissues from liver biopsy of patients with hepatitis C virus (HCV)-related cirrhosis and HCC were immunohistochemically stained and SELM expression scoring was evaluated. Our results evidence for the first time an increase of SELM expression in HCC liver tissues, and its gradual expression raise associated with an increased malignancy grade. Therefore, we propose to use i) SELM as putative marker for HCC as well as ii) simple immunohistochemistry technique to distinguish between the different grades of malignancy.