miR-128 targets the CC chemokine ligand 18 gene (CCL18) in cutaneous malignant melanoma progression

Abstract

Background: The CC chemokine ligand 18 (CCL18) has a higher expression in some tumors, while the CCL18 level can be a marker of tumor progression and prognosis. We previously reported that the expression of CCL18 gene was dramatically up-regulated in cutaneous malignant melanoma (CMM) and its expression levels were correlated with tumor thickness.

Objective: To investigate miRNAs which could target the CCL18 gene so as to mediate CMM development and improvement.

Methods: The expression of miR-128 and CCL18 in CMM were measured by qRT-PCR. The interaction of miR-128 with CCL18 3'UTR was verified by Luciferase reporter gene assay. The changes in expression of CCL18 after miR-128 mimic transfection of A375 melanoma cells were determined by both qRT-PCR and Western-bloting. Cell viability was accessed by CCK8-assay. Flow cytometry was employed to detect the incidence of apoptosis. Clonogenic assay was used to detect the ability of colony formation. Cell migration was evaluated by Transwell migration study. The protein levels of epithelial-mesenchymal transition (EMT), such as E-cadherin, N-cadherin and β-catenin were analyzed by Western-bloting.

Results: The expression of miR-128 had negative relevance with CCL18 in CMM. miR-128 could interact with CCL18 3'UTR. Transfected miR-128 mimic significantly reduced CCL18 expression and this impairment of CCL18 gene promoted apoptosis, inhibited migration and colony formation of A375 melanoma cells. Furthermore, the relative expression of N-cadherin was decreased.

Conclusion: CCL18 is a target gene of miR-128. Overexpression of miR-128 inhibits the oncogenic effect of CCL18.

Keywords: CCL18; Malignancy; Malignant melanoma; Overexpression; miR-128.