Elevated serum microRNA-122/222 levels are potential diagnostic biomarkers in Egyptian patients with chronic hepatitis C but not hepatic cancer

MicroRNAs (miRNAs) are a class of endogenous small non-coding RNAs that regulate gene expression at the post-transcriptional level. Because of their size, specificity, and relative stability in plasma, miRNAs can be used as diagnostic and prognostic biomarkers to monitor liver injury, such as that caused by hepatitis C virus (HCV) and liver cancer. In this study, we investigated miRNA expression patterns from the serum of Egyptian patients with HCV and liver cancer compared with matched healthy controls. Using microarray-based expression profiling followed by real-time quantitative polymerase chain reaction validation, we compared the levels of circulating miRNA-122 and miRNA-222 in serum from patients with hepatitis C virus (n = 40) and liver cancer (n = 60) to matched healthy controls (n = 30). MiRNA SNORD68 was the housekeeping endogenous control. We found that the serum levels of miR-122 and miR-222 were significantly elevated in HCV patients, but not in liver cancer patients, compared with controls. Receiver operating characteristic analysis revealed that miR-122 and miR-222 have a high diagnostic potential in discriminating patients with HCV from controls. Serum miR-222 was significantly higher in HCV patients compared to liver cancer patients. Our results indicate that serum miR-122 and miR-222 are elevated in Egyptian patients with chronic HCV, and these miRNAs have a strong potential to serve as novel biomarkers for liver injury but not specifically for liver cancer.