SHP2 mediates STAT3/STAT6 signaling pathway in TAM to inhibit proliferation and metastasis of lung adenocarcinoma

Objective: This study examines SHP2's influence on the STAT3/STAT6 pathway in tumor-associated macrophages (TAMs) and its impact on lung adenocarcinoma proliferation and metastasis. Methods: Lung cancer A549 and NCI-H1688 cell lines were subcutaneously injected into nude mice. Macrophages were isolated using flow cytometry and analyzed for CD163, CD206, and Arginase-1 levels via western blot. Similarly, the effect on THP1 cell-associated proteins was assessed. The impact on A549 and NCI-H1688 cell migration, invasion, and proliferation was evaluated through wound healing, Transwell assays, and CCK8. Results: Compared to controls, the sh-RNA SHP2 group showed increased tumor volume and higher expression levels of CD163, CD206, Arginase-1, p-STAT3, p-STAT6, IL-4, IL-10, and various cathepsins in macrophages and THP1 cells. However, p-STAT1 and p-STAT5 levels remained unchanged. The sh-RNA SHP2 group also demonstrated enhanced migration, invasion, and proliferation in both cell lines. Conclusions: SHP2 negatively affects the STAT3/STAT6 pathway in TAMs, promoting M2 polarization and cathepsin secretion, which enhances lung adenocarcinoma cell proliferation and metastasis.