Ubiquitin C-terminal hydrolase L1 promotes expression of programmed cell death-ligand 1 in non-small-cell lung cancer cells.

Programmed cell death-ligand 1 (PD-L1) expressed on cancer cells can cause immune escape of non-small-cell lung cancer (NSCLC). Elucidation of the regulatory mechanisms of the PD-L1 expression is a prerequisite for establishing new tumor immunotherapy strategies. Ubiquitin C-terminal hydrolase L1 (UCHL1) is a regulator of cellular signaling transduction that is aberrantly expressed in NSCLC. However, it is not known whether UCHL1 regulates the expression of PD-L1 in NSCLC cells. In the present study, we found that UCHL1 promotes the expression of PD-L1 in NSCLC cell lines. In addition, UCHL1 expressed in NSCLC cells inhibited activation of Jurkat cells through upregulation of PD-L1 expression in in vitro experiments. Moreover, UCHL1 upregulates PD-L1 expression through facilitating activation of the AKT-P65 signaling pathway. In conclusion, these results indicated that UCHL1 promoted PD-L1 expression in NSCLC cells. This finding implied that inhibition of UCHL1 might suppress immune escape of NSCLC through downregulation of PD-L1 expression in NSCLC cells.