FGFR2 promotes expression of PD-L1 in colorectal cancer via the JAK/STAT3 signaling pathway

P Li, T Huang, Q Zou, D Liu, Y Wang, X Tan… - The Journal of …, 2019 - journals.aai.org
P Li, T Huang, Q Zou, D Liu, Y Wang, X Tan, Y Wei, H Qiu
The Journal of Immunology, 2019journals.aai.org
Although multidisciplinary treatment is widely applied in colorectal cancer (CRC), the
prognosis of patients with advanced CRC remains poor. Immunotherapy blocking of
programmed cell death ligand 1 (PD-L1) is a promising approach. Binding of the
transmembrane protein PD-L1 expressed by tumor cells or tumor microenvironment cells to
its receptor programmed cell death 1 (PD-1) induces immunosuppressive signals and
reduces the proliferation of T cells, which is an important mechanism of tumor immune …
Abstract
Although multidisciplinary treatment is widely applied in colorectal cancer (CRC), the prognosis of patients with advanced CRC remains poor. Immunotherapy blocking of programmed cell death ligand 1 (PD-L1) is a promising approach. Binding of the transmembrane protein PD-L1 expressed by tumor cells or tumor microenvironment cells to its receptor programmed cell death 1 (PD-1) induces immunosuppressive signals and reduces the proliferation of T cells, which is an important mechanism of tumor immune escape and a key issue in immunotherapy. However, the regulation of PD-L1 expression is poorly understood in CRC. Fibroblast growth factor (FGF) receptor (FGFR) 2 causes the tyrosine kinase domains to initiate a cascade of intracellular signals by binding to FGFs and dimerization (pairing of receptors), which is involved in tumorigenesis and progression. In this study, we showed that PD-L1 and FGFR2 were frequently overexpressed in CRC, and FGFR2 expression was significantly associated with lymph node metastasis, clinical stage, and poor survival. In the current study, PD-L1 expression was positively correlated with FGFR2 expression in CRC. Tumor-derived–activated FGFR2 induced PD-L1 expression via the JAK/STAT3 signaling pathway in human CRC cells (SW480 and NCI-H716), which induced the apoptosis of Jurkat T cells. FGFR2 also promoted the expression of PD-L1 in a xenograft mouse model of CRC. The results of our study reveal a novel mechanism of PD-L1 expression in CRC, thus providing a theoretical basis for reversing the immune tolerance of FGFR2 overexpression in CRC.
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