Tumor-associated macrophages induce PD-L1 expression in gastric cancer cells through IL-6 and TNF- ɑ signaling.

In this study, we found a high correlation between macrophage infiltration and PD-L1 expression in gastric cancer (GC) specimens. Further study revealed that infiltrated macrophages released the proinflammatory cytokines TNF-ɑ and IL-6, which induced PD-L1 expression in tumor cells. The release of TNF-ɑ and IL-6 activated the NF-kB and STAT3 signaling pathway to regulate PD-L1 expression. TNF-α, p-65 and STAT3 expression in cancer patients has prognostic value in stomach adenocarcinoma. Furthermore, infiltrated macrophages can also promote GC cell proliferation by inducing PD-L1 expression in GC cells. Taken together, our results suggest that macrophages play a dual role in regulating the expression of PD-L1 in tumor cells. On the one hand, macrophages induce PD-L1 expression in tumor cells, helping tumor cells escape cytotoxic T cell killing; on the other hand, they can promote the proliferation of tumor cells by regulating the expression of PD-L1. PMID: 33031808 [PubMed - as supplied by publisher]
Source: Experimental Cell Research - Category: Cytology Authors: Tags: Exp Cell Res Source Type: research