Evaluation of Long non coding RNA Expression in Hepatocellular Carcinoma: Dysregulation and Implications for Early Detection

Abstract

SUMMARY H epatocellular Carcinoma (HCC) represents the fifth most common cancer in the world and the second most frequent cause of mortality among oncological patients. It is responsible for 500,000 deaths globally every year. It represents the most common primary malignant tumor of the liver, Its incidence is increasing because of hepatitis B and C virus infections. Egypt has the highest prevalence of HCV in the world with 13.8% of the population infected and seven million with chronic HCV liver disease. Up to 90% of HCC cases in the Egyptian population were attributed to HCV. Early detection of HCC opens doors for various effective treatments such as surgical resection, radiofrequency ablation, and transplantation, which can subsequently lead to long-term survivals in a great number of HCC patients. Early detection is possible with ultrasound scanning and AFP monitoring, although the use of AFP as a screening test is complicated by frequent false positive and false negative results. In addition, AFP serum concentrations do not correlate well with the prognostic parameters of HCC such as tumor size, stage, or disease progression. Ethnic variability may also exist. Furthermore, in some cases of HCC, AFP elevations are not apparent at all. Besides, serum AFP levels are frequently not elevated at a significant proportion in patients with early-stage potentially curable HCC. Therefore, other markers should be studied in an attempt to identify a more sensitive laboratory test. Several lines of evidence have suggested that lncRNAs are biologically functional rather than transcriptional “noise”. The mechanisms through which they act are molecular scaffolds, which are involved in transcriptional machinery, as post-transcriptional regulators of splicing or as molecular decoys for miRNA. lncRNA-UCA1 plays oncogenic roles in tumor growth and metastasis, and it may act as a potential biomarker and therapeutic target for human cancers. As it is upregulated in several cancers LncRNA-WRAP53 is a natural p53 antisense transcript that play a role in regulation of the corresponding sense gene expression.It is a novel long non-coding RNA acts as a crucial effectors in several cancers and it is capable of regulating p53 levels in both normal and cancer cell line. In this regards, we evaluated the clinical utility of serum levels of lncRNA-UCA1 and lncRNA-WRAP53expression as non invasive biomarkers in diagnosis of HCC and to correlate their expression with different clinicopathological factors. This study was done at Medical Biochemistry Department, Faculty of Medicine, Ain Sham University during the period from June 2013 – June 2015 and included 58 patients and 22 healthy volunteers. The aim of the current study was to evaluate the clinical utility of serum levels of lncRNA-UCA1 and lncRNA-WRAP53 expression as non invasive biomarkers in diagnosis of HCC by quantitive Real Time –PCR. Also, to correlate the expression of both genes with the various clinico-pathological parameters in an attempt to evaluate the role of lncRNA-UCA1 and lncRNA-WRAP53 in tumor assessment and to explore their synergistic expression and their use as potential selected diagnostic biomarkers. The studied individuals were classified into three main groups: Group 1, including 41 patients with hepatocellular carcinoma, median age was 57 years. Group 2, including 17 patients with chronic hepatitis C virus infection, median age was 57 years Group 3, including 22 healthy normal controls, median age was 57 years All studied subjects in this study were subjected to Full clinical examination and radiological examinations preceded by complete history taking and routine laboratory investigations including liver function tests as serum ALT, serum AST, serum albumin, prothrombin time and serum total bilirubin,serum AFP. Evaluation of lncRNA-UCA1 and lncRNA-WRAP53 expression in serum samples was performed by Real-Time PCR in relation to GAPDH as the reference gene in all samples. Then the results were calculated and statistically analyzed by the SPS software. A significant difference was observed in the Positivity rate of lncRNA-UCA1 and lncRNA-WRAP53 in serum samples of the malignant group i.e. (92.7%, 85.4%) as compared with both CHC group (41.2%,29.4%) and healthy control group (0%,9.1%) respectively (P= 0.000).