The pathogenic germline ETV4 P433L mutation identified in multiple primary lung cancer affect tumor stem-like property by Wnt/β-catenin pathway

The occurrence of multiple primary lung cancer (MPLC) has witnessed a significant surge in recent years within the Chinese population. MPLC is distinguished by its potential genetic susceptibility and notable genetic heterogeneity. Investigating the etiology of MPLC holds substantial clinical importance.The whole genome sequencing (WGS) and genome-wide linkage analysis were performed in a family affected by a dominant form of lung abnormalities. Specifically, five family members were diagnosed with MPLC, while nine members had pulmonary nodules and one normal member. To confirm the potential pathogenic germline mutations sites, Sanger sequencing was performed in an additional 162 MPLC family patients. Furthermore, molecular biology experiments were conducted to investigate the function and the mechanism of the identified pathogenic mutation site in lung cancer A549 and H322, both in vitro and in vivo. Linkage analysis revealed the presence of shared genomic regions among affected family members. Subsequent exome sequencing identified a deleterious variant within these linkage intervals, specifically a heterozygous mutation in ETS-oncogene transcription factors 4 (ETV4). This particular variant was found in affected family members at a rate of 13 out of 15 individuals. Furthermore, ETV4 P433L mutation could be detected in an additional MPLC family patients and mutation frequency was 3.7% (6 out of 162). The ETV4 P433L mutations site was introduced into lung cancer cell lines, resulting in altered migration and stem-like properties of the cancer cells. Further investigation revealed that the activation of the Wnt/β-catenin signaling pathway, which is associated with stemness, could be attributed to the presence of the ETV4 P433L mutation, suggesting its involvement in tumor promotion. A novel pathogenic germline mutation, ETV4 P433L, was identified in a dominant MPLC family, with a mutation rate of 3.7% among MPLC family patients. The ETV4 P433L mutation was found to impact the stem-like properties and migration of tumors through Wnt/β-catenin signaling pathway.