NFATc1 activates the Ras/Raf/p38 MAPK pathway to promote the progression of lung adenocarcinoma.

Background: The incidence rate and mortality rate of lung adenocarcinoma (LUAD) are in the forefront of malignant tumors in recent years. Due to its atypical early manifestations, many patients are diagnosed at advanced stages and miss the opportunity for timely intervention, resulting in a poor 5-year overall survival rate. Therefore, identifying specific targets in LUAD is essential for molecular precision therapy. This study integrates clinical and basic research to elucidate the diagnostic value and clinical significance of nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) in LUAD. Methods: Immunohistochemistry (IHC) and immunofluorescence (IF) were first employed to detect the protein expression and localization of NFATc1 in LUAD and adjacent tissues. Receiver operating characteristic (ROC) curve analysis was then performed to evaluate the diagnostic potential of NFATc1 for LUAD, and to analyze the correlation between NFATc1 expression and clinical data of LUAD patients. Subsequently, NFATc1 messenger RNA (mRNA) and protein expression in A549 LUAD cells were measured using real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot assays. The effects of NFATc1 silencing on cell proliferation, migration, and invasion were assessed using Cell Counting Kit-8 (CCK-8), colony formation, wound healing, and Transwell assays. Finally, the signaling pathway, underlying mechanisms and gene alterations types through which NFATc1 influences LUAD progression were predicted and validated. Results: NFATc1 expression was higher in LUAD tissues than in adjacent normal tissues and was localized in both the cytoplasm and nucleus. Area under the curve (AUC) of NFATc1 in diagnosing LUAD was 0.8020. NFATc1 expression was related to clinical stage, T stage, N stage, pathological grading, and maximum diameter of LUAD. NFATc1 expression in human LUAD (A549) cell line was significantly higher than in human normal lung epithelial BEAS-2B cell line. Silencing NFATc1 reduced the proliferation, migration, and invasion of A549 cells. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested that NFATc1 may be associated with the Ras/Raf/p38 mitogen-activated protein kinase (MAPK) pathway. Pretreatment with the inhibitor SB202190 decreased the expression of proteins related to Ras/Raf/p38 MAPK and significantly suppressed the proliferation, migration, and invasion of A549 cells. Public database analyses revealed that the NFATc1 alterations in LUAD primarily involve gene deletions and gene mutations. Conclusions: NFATc1 is highly expressed in LUAD tissues, and its expression level is closely related to clinical characteristics. NFATc1 may promote the proliferation, migration, and LUAD cell invasion via the Ras/Raf/p38 MAPK pathway, providing a new therapeutic target for LUAD.