The miR-3127-5p/p-STAT3 axis up-regulates PD-L1 inducing chemoresistance in non-small-cell lung cancer.

It is less known about miRNA3127-5p induced up-regulation of PD-L1, immune escape and drug resistance caused by increased PD-L1 in lung cancer. In this study, lentivirus was transduced into lung cancer cells, and quantitative PCR and Western blot were used to detect the expression of PD-L1. Then immunofluorescence assay was applied to detect autophagy, finally we explored the relationship between PD-L1 expressions and chemoresistance in patients. As a result, we found that microRNA-3127-5p promotes pSTAT3 to induce the expression of PD-L1; microRNA-3127-5p promotes STAT3 phosphorylation through suppressing autophagy, and autophagy could retaine pSTAT3 into the nucleus in miRNA-3127-5p knocked cells, and immune escape induced by elevated level of PD-L1 results in chemoresistance of lung cancer. In conclusion, microRNA-3127-5p induces PD-L1 elevation through regulating pSTAT3 expression. We also demonstrate that immune escape induced by PD-L1 can be dismissed by corresponding monoclonal antibody.