New Dancing Couple: PD-L1 and MicroRNA.

Lung cancer (LC) is the most common cause of cancer death in the world. A great challenge in treating NSCLC is the discovery of advanced, molecular tools to diagnose the disease in early stages as well as the development of immunotherapy. MicroRNAs are regulatory molecules (~20 nt in length) with the ability to regulate the expression of genes. The recently described PD-1 and PD-L1 molecules have great importance for potential use in immunotherapy of many cancers. These molecules are associated with immune checkpoints and provide an opportunity for the treatment of advanced NSCLC patients with synthetic monoclonal antibodies. PD-L1 expression is strictly associated with microRNA function in lung cancer cells. The group of microRNAs related to PD-L1 includes, among others, miR-200, miR-197 or miRNA-34. Expression of these molecules may be useful in lung cancer diagnosis, qualification to anti-PD-1 or anti-PD-L1 antibody therapy and could be a potential therapeutic target. However, studies on PD-L1-related microRNAs are necessary to develop advanced targeted molecular therapies.