Role of MicroRNA-7 and Selenoprotein P in Hepatocellular Carcinoma

Abstract

HCC is a public health priority worldwide. Itrepresents the fifth most common cancer and the third leading cause of cancer related death. In Egypt, it is the second most common malignancy after bladder cancer in men and breast cancer in women and the second most common cause of death in men. High morbidity observed in HCC is majorly attributed to lack of early detection markers and poor prognosis. Hence, there is an obvious need to diagnose HCC using novel non-invasive and sensitive biomarkers in order to accurately identify the high risk population for optimal treatments and minimize unnecessary invasive procedures. Deregulation of miRNAs, including miR-7, has been found to be involved in the pathogenesis of HCC and have been suggested as potential biomarkers for HCC.Several targets of miR-7 have been identified so far, one of which is SeP; an extracellular protein produced primarily by the liver and transports Se from the liver to extrahepatic tissues and protects against oxidative injury. It has been suggested to be the most sensitive measure of Se nutritional status. In this regard, serum miR-7 levels based on RQ values were detected in the different investigated groups aiming to evaluate its clinical significance in HCC. In addition, quantitative analysis of serum SeP was done using ELISA to detect its role in HCC and to relate miR-7 and SeP to each other and to different clinicopathological factors. To the best of our knowledge this study is the first study to evaluate the role of miR-7 in sera of HCC patients aiming to suggest a potential diagnostic biomarker with a valid non-invasive technique. In addition, the present work investigated whether changes in Se supply (in the form of selenite) affected miR-7 expression and SeP levels in human hepatocarcinoma cell line (HepG2). This study was conducted on (60) patients attending the Tropical Medicine department at Ain Shams University Hospitals. Patients were classified into twogroups according to their diagnosis. Group (1) included (30) newly diagnosed HCC patients. Group (2) included (30) patients with CLD. In addition, (30) apparently healthy subjects served as control group. The results of the current study revealed the following: Serum miR-7 RQ values and serum levels of SeP were significantly lower in the HCC group compared to both CLD and healthy control groups (p<0.01).