Mechanism of CPNE3 regulating proliferation, migration and invasion of non-small cell lung cancer cells

Abstract

Objective To investigate the effect of CPNE3 on the proliferation, migration and invasion of non-small cell lung cancer (NSCLC) cell line A549 and its underlying mechanism. Methods The expression of CPNE3 in NSCLC and its relationship with prognosis were analyzed based on the data from the cancer genome atlas (TCGA) database. Western blotting was used to detect the expression of CPNE3 in normal bronchial epithelial cell line BEAS-2B and lung cancer cell lines. The si-RNAs of CPNE3 were transfected into A549 cells. The abilities of cell proliferation, migration and invasion were detected by CCK-8 assay, colony formation assay, and Transwell assay, respectively, and the expression levels of downstream proteins related to proliferation and metastasis were detected by Western blotting. After the A549 cells with stable overexpression of CPNE3 were established, the cells with overexpression or not were respectively employed to construct lung carcinoma xenograft model in female BALB/c nude mice (n=5 for control and overexpression mice, respectively). Then the tumor growth was observed to determine the effect of CPNE3 overexpression on the tumorigenicity of A549 cells. Results The expression of CPNE3 was increased in NSCLC tissues (P < 0.05), and its high expression was correlated with poor prognosis (P < 0.01). Consistently, the expression of CPNE3 was increased in lung cancer cell lines (P < 0.01). After the knockdown of CPNE3, the proliferation and colony formation (P < 0.001, P < 0.01), and migration and invasion abilities (P < 0.01, P < 0.01) were significantly inhibited in A549 cells, accompanied with decreased phosphorylation levels of AKT, ERK, and EGFR (P < 0.001, P < 0.001, P < 0.01). Overexpression of CPNE3 promoted cell proliferation in vivo (P < 0.001), and upregulated phosphorylation of AKT, ERK, and EGFR (P < 0.05, P < 0.05, P < 0.01). Conclusion Knocking CPNE3 down can inhibit the proliferation, migration and invasion of A549 cells, while its overexpression can promote the proliferation ability of A549 cells in vivo, which may be related to EGFR signaling pathway and downstream AKT/ERK signaling pathway.

Keywords

• cpne3
• proliferation
• migration
• invasion
• lung cancer
• non-small cell lung cancer