MicroRNA-155 Gene Expression and Association with Hepatitis B Virus Genotypes and Drug Resistance in a Sample of Iraqi Patients

Abstract

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally. miR-155, a pro-inflammatory oncomiR, plays a key role in immunological processes and various pathological conditions, including viral infections, hepatic fibrosis, and hepatitis B virus-associated hepatocellular carcinoma (HCC). The present study aimed to evaluate miRNA-155 expression in patients with HBV infection in Iraq and its association with viral genotypes and drug resistance. The methodology involved assessing miR-155 by RT-qPCR in 100 HBV-infected patients and 50 healthy controls between November 2023 and June 2024. The results revealed a marked overexpression of miR-155 in HBV patients (8.3±3.6) compared to controls. Furthermore, a significant difference in expression fold change was observed between female and male patients (p=0.04), with significant variation in some age groups. Notably, a significant difference in miR-155 expression was observed across different HBV sub-genotypes (HBV-D1/D3, p=0.013), as well as in antiviral drug resistance (p=0.017). Also, no association was observed between viral load and gene expression by Spearman r correlation (p=0.39). To our knowledge, this is the first local study to explore the relationship between miR-155 expression and both HBV sub-genotypes and drug resistance. In conclusion, these findings suggest that miR-155 may serve as a potential non-invasive biomarker for monitoring the progression of HBV infection and for identifying drug resistance, pending further validation.