The expression of FOXC1 in non-small cell lung cancer and its effect on the biological behavior of carcinoma cells

Objective: To investigate the impact of FOXC1 expression on the clinical prognosis of non-small cell lung cancer (NSCLC) patients and the biological behavior of NSCLC cells. Methods: We analyzed the correlations of the expression pattern of FOXC1 with patients' clinicopathological features and prognosis. Immunohistochemical staining was carried out to determine the expressions of FOXC1 in the NSCLC tissues and the corresponding tumor-adjacent normal tissues in 97 patients. Additionally, A549-shFOXC1 cell lines were constructed, with the A549-shNC cell line and the A549 cell line as the negative control and blank, respectively. FOXC1 expressions were determined using Western blot in the cell lines and the normal human lung cell line MRC-5. Furthermore, the proliferation and invasion abilities of these NSCLC lines were determined using a plate colony formation assay and a Transwell assay. Results: Compared with the tumor-adjacent normal tissues, the positive expression rate of FOXC1 was significantly higher in the NSCLC tissues (P < 0.05). Tumor malignancy and the positive expression rate of FOXC1 are positively correlated with TNM stage, number and size of lymphatic metastatic regions, tumor diameter, and tissue infiltration. Patients with positive expressions of FOXC1 had a 5-year survival rate of 11.11%, which is 28.00% lower than those with negative expressions of FOXC1 (P < 0.05). Compared with the MRC-5 cell line, FOXC1 was observably up regulated in the A549 cell line (P<0.05), and the knockdown of FOXC1 decreased the proliferation and invasion of the A549 cells (P < 0.05). Conclusion: FOXC1 is highly expressed in NSCLC, and its expression is significantly correlated with patients' prognosis. Furthermore, FOXC1 promotes the proliferation and invasion of A549 cells.