Glycodelin: A New Biomarker with Immunomodulatory Functions in Non-Small Cell Lung Cancer.

In recent years, immune therapeutic strategies against non-small cell lung cancer (NSCLC) based on tissue-derived biomarkers, for example PD1/PD-L1 (CD274), have evolved as novel and promising treatment options. However, the crosstalk between tumor and immune cells is poorly understood. Glycodelin (gene name PAEP), initially described in the context of pregnancy and trophoblastic implantation, is a secreted immunosuppressive glycoprotein with an as-of-yet largely unknown function in lung cancer. In this study, we characterized the expression and role of glycodelin in NSCLC through mRNA and protein expression analyses, functional knockdown experiments, and correlations with clinicopathologic parameters. Glycodelin mRNA expression was significantly elevated in tumors (n = 336) compared with matched normal tissue (P < 0.0001). Overall survival (OS) was significantly reduced in NSCLC with high glycodelin mRNA levels in women but not in men. Glycodelin was detected in the sera of patients, and the levels correlated with recurrence and metastatic disease. Knockdown of glycodelin with siRNAs in NSCLC cell lines resulted in significant upregulation of immune system modulatory factors such as PDL1, CXCL5, CXCL16, MICA/B, and CD83 as well as proliferation stimulators EDN1 and HBEGF. Furthermore, decreased migration of tumor cells was observed. Altogether, the comprehensive characterization of glycodelin in NSCLC provides strong support for its use as a biomarker with immune modulatory function.