H2-calponin attenuate metastasis in human NSCLC by suppressing RSK2 expression.

Lung cancer is the most common cause of cancer-related death. However, survival rates for advanced non-small cell lung cancer (NSCLC) have not improved as expected. Identifying the genes that regulate metastatic pathways is a pressing challenge in cancer therapy, as it is crucial to understand the molecular mechanisms underlying metastasis. In this study, we performed both immunohistochemical and overall survival analyses. Additionally, we performed wound healing and transwell assays to validate the changes in metastatic ability among NSCLC cell lines, and a vein injection metastasis model was used to validate our findings in vivo. Rhodamine-phalloidin staining was used to display actin stress fiber reorganization among the cell lines. We also conducted RNA interference target sequence screening to identify the target genes of the h2-calponin knockdown. To explore how h2-calponin regulates RSK2 expression, we performed a luciferase reporter assay. Our findings indicate that low h2-calponin expression is associated with aggressive clinical outcomes in patients with NSCLC and is an independent prognostic factor. Down-regulation of h2-calponin improved tumor migration, invasion, and metastasis, whereas up regulation led to a reverse outcome. Activation of RSK2/HSP27/CREB is responsible for the improvement in metastatic abilities. There was a mild correlation between the expression levels of h2-calponin and RKS2 in NSCLC patients. Moreover, h2-calplow/RSK2high patients experienced shorter survival periods than did h2-calphigh/RSK2low patients. Our findings reveal a novel regulatory pathway involving the actin-binding protein h2-calponin and phosphorylase RSK2, which is involved in tumor metastasis. This signaling pathway could serve as a potential therapeutic avenue for treating NSCLC.