MicroRNAs: Regulators of immunological reactions in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third prominent cause of cancer mortality, with increasing prevalence and poor survival worldwide. Being diagnosed at an advanced stage, HCC frequently results in poor prognosis, treatment failure, and recurrence. Post-treatment reactivation and recurrence often amplify the immunosuppressed state induced by HCC pathogenesis. Therefore, stimulating the immune system may be a potential therapy measure for the treatment of HCC. Immune responses of the body may be potentiated by modulation of various effector cells such as B-cells, T-cells, Treg cells, natural killer cells, dendritic cells, cytotoxic T-lymphocytes, and other antigen-presenting cells. microRNAs (small non-coding RNAs) are the regulators of gene expression via translational inhibition or mRNA degradation. Various activities and developmental stages of the immune system are governed by miRNAs and they have a regulative impact on innate and adaptive immune cells in both, healthy and diseased conditions. Their misexpression has been associated with the initiation, development, and metastasis of various cancer types, including HCC. This review summarizes the functional impact of these immuno-miRNAs in the improvement of tumor conditions.