P2.03b-085 Programmed Cell Death Ligand 1 (PD-L1) Expression in Stage II and III Lung Adenocarcinomas

Abstract

Background: For late stage lung cancer (LC) patients few treatment options are at hand and the survival time is very limited, hence novel therapies and associated biomarkers are urgently needed. Erythropoietin-Producing Hepatocellular carcinoma receptor (Eph) tyrosine kinase family and their ligands, Ephrins, drive multiple hallmarks of cancer e.g. proliferation/invasion. The Eph signaling pathways are attractive drug targets due to their dual role in oncogenesis and tumor progression. We analyzed Ephs/Ephrins signaling in LC cells from pleural effusions (PE) to reveal altered kinase pathways and putative BMs. We also assessed cytotoxicity and kinome alterations in PE tumor cells exposed to targeted agents and chemotherapy in vitro. Methods: Tumor cells purified from PE, assessed for histology, mutation and translocation status (EGFR, KRAS, BRAF and Alk), were grown in vitro. Toxicity of tyrosine kinase inhibitors (TKIs (e.g. erlotinib, crizotinib, AG1024, AZD9291, dasatinib), EGFR blocker (cetuximab) and/or chemotherapy (e.g. cisplatin, gemcitabine, etoposide) were analyzed after 72 h with the Tox8 assay. Ephs/Ephrins signaling components were studied using western blot, immunoprecipitation and by proximity ligation assay. Mutations and signaling heterogeneity were visualized using padlock probe method. For kinome profiling PathScan RTK signalling antibody array was used.