α5-nAChR/NETO2 contributed to chronic stress-promoted lung adenocarcinoma progression

α5-nicotinic acetylcholine receptor (α5-nAChR) participates in chronic stress-promoted lung adenocarcinoma (LUAD) progression. Neuropilin and tolloid-like 2 (NETO2) contributes to fear expression and extinction, which is related to tumorigenesis. CHRNA5 (encoding α5-nAChR) gene profiling revealed a reduction in NETO2 expression following CHRNA5 knockdown. Nevertheless, the connection between α5-nAChR and NETO2 in LUAD progression induced by chronic stress remains unclear.

RNA-Seq and bioinformatics database were used for analyzing the expression as well as correlation of α5-nAChR, together with NETO2 in LUAD. α5-nAChR and NETO2 expression were detected using immunohistochemistry in LUAD tissue microarrays, chronic restraint stress (CRS) and chronic unpredictable stress (CUMS) mice tissues. In lung adenocarcinoma A549 and H1299 cells, the expression of α5-nAChR, NETO2, p-CAMKII, p-STAT3 and vimentin induced by acetylcholine/nicotine was examined by western blot. The interaction of α5-nAChR with NETO2 in lung adenocarcinoma cells was detected by Co-immunoprecipitation assay and modeled using molecular docking. EdU assay and colony formation assay were conducted to evaluate cell proliferation, while wound healing assay as well as transwell assay assessed the migration and invasion of lung adenocarcinoma cells.

α5-nAChR expression was related to NETO2 expression, low survival rate, staging as well as smoking status in LUAD dataset as well as tissue microarrays. The correlation between α5-nAChR and NETO2 was validated in nude mice xenograft tissues. α5-nAChR as well as NETO2 expression correlated in CRS and CUMS mice tissues. In vitro, acetylcholine/nicotine mediated NETO2, p-CAMKII, p-STAT3 and vimentin expression via α5-nAChR. α5-nAChR interacted with NETO2 as well as CAMKII in LUAD cells. α5-nAChR/NETO2 signaling contributed to LUAD cell proliferation, migration and invasion.

The above results uncover a new chronic stress-promoted LUAD signaling pathway: α5-nAChR/NETO2 axis contributes to chronic stress-promoted LUAD cell proliferation, migration and invasion.