The impact of neuron-related cell adhesion molecule on cellular biological functions and its clinical significance in small-cell lung cancer.

BACKGROUND: Neuron-related cell adhesion molecule (NrCAM) has been implicated in tumor progression, but its role in small-cell lung cancer (SCLC) remains unclear. This study examined the clinical significance of NrCAM in SCLC and its impact on cellular processes. METHODS: Differentially expressed genes (DEGs) in SCLC were identified from The Cancer Genome Atlas (TCGA) datasets (GSE6044, GSE111044, and GSE44447) according to a |log fold change (FC)| >2 and a P value <0.05. Clinical and pathological data, along with tumor tissue samples, were obtained from 43 patients with SCLC treated at Nantong Tumor Hospital from 2017 to 2019. NrCAM expression was analyzed via immunohistochemistry. NrCAM knockdown or overexpression models were established in SCLC cell lines to evaluate proliferation, colony formation, migration, and invasion in vitro. A xenograft mouse model was used to assess NrCAM's effects in vivo. RESULTS: Immunohistochemical analysis revealed higher NrCAM expression in SCLC tissues as compared to adjacent noncancerous tissues. Patients with high NrCAM expression exhibited shorter survival (P=0.04) and significant associations with tumor-node-metastasis (TNM) stage, tumor size, and differentiation grade (P<0.05). Multivariate Cox analysis identified high NrCAM expression as an independent risk factor for poor prognosis (P=0.04). NrCAM knockdown significantly inhibited SCLC cell proliferation, migration, and invasion (P<0.05), while NrCAM overexpression resulted in the opposite effects. In the xenograft model, NrCAM knockdown reduced tumor volume and Ki-67 expression (P<0.05). CONCLUSIONS: NrCAM overexpression in SCLC is associated with poor prognosis. Knockdown of NrCAM expression inhibited the proliferation, migration, and invasion of SCLC cells, suggesting that NrCAM could be a potential biomarker for diagnosis and prognostic evaluation in SCLC.