Expression of CCL18 gene in ovarian cancer and its impact on the biologic function of ovarian cancer cells

The aim of the present study was to evaluate the expression of the chemokine ligand 18 (CCL18) gene in ovarian cancer and to investigate the effects of its overexpression or suppression on growth, invasion, and metastasis in an ovarian carcinoma cell line (SKOV3) in vitro. CCL18 mRNA expression in epithelial ovarian carcinoma (EOC), benign ovarian tumor and normal ovarian tissues was measured by fluorescence quantitative polymerase chain reaction. A CCL18 restructuring plasmid was constructed, and SKOV3 cells were transfected with the plasmid DNA in vitro. A restructuring interference vector was also transfected into CCL18-positive SKOV3 cells. The growth curves, cell cycle distribution, and invasive, migrative and adhesive capacities of SKOV3 cells following overexpression and suppression of CCL18 were evaluated by MTT assay, flow cytometry, Transwell assay, migration assay, and the fibronectin adhesion method, respectively. The positive expression rate of CCL18 in EOC was significantly higher than in benign ovarian tumor (P = 0.002) and normal ovarian tissues (P = 0.003). However, there was no statistical significance in the expression of CCL18 with regard to clinical pathology (including histological classification, pathological grade and surgical pathological stage), and the median survival times of CCL18-positive and CCL18-negative patients did not differ significantly. The invasive, migrative, and adhesive capacities of SKOV3-CCL18 cells were significantly higher than those of SKOV3 and SKOV3-vector cells (P < 0.05). However, there was no significant difference in cell proliferation between the SKOV3-CCL18 and negative control cells. The invasive, migrative, and adhesive capacities of the pSilencer4.1-CCL18-small interfering RNA127 group were significantly lower than those of non-transfected pSilencer4.1-negative and pSilencer4.1 groups (P < 0.05). In conclusion, the overexpression and silencing of CCL18 affected invasion, adhesion, and migration in EOC cells; thus CCL18 may have potential as a clinical marker for early diagnosis of malignant ovarian tumors, and as a target molecule in the treatment of ovarian cancer.