MiR-302c regulates the expression of CXCL8 to inhibit the proliferation and invasion of esophageal squamous cell carcinoma cells

ObjectiveTo investigate the effects of miR-302c on regulating the expression of CXC chemokine ligand 8 (CXCL8) on the proliferation and invasion of esophageal squamous cell carcinoma (ESCC) cells.

MethodsThe ESCC tissues and their corresponding adjacent tissues were collected from ESCC patients who underwent surgical treatment, as well as human ESCC cell lines Eca109, Ec9706, TE-11, TE-10 and normal esophageal epithelial cell line Het-1A were set as the study subjects, the expression of miR-302c was detected by qRT-PCR.Eca109 cells were transfected with Lipofectamine^TM2000 transfection kit and divided into blank group (cells not transfected), miR-NC group, miR-302c mimics group, si-CXCL8 group, si-NC group, miR-302c mimics +OE-NC group and miR-302c mimics+OE-CXCL8 group, the expression of miR-302c in each group was detected by qRT-PCR; the cell proliferation in each group was detected by MTT method; the cell invasion in each group was detected by Transwell assay; the dual luciferase reporter gene detection experiment was used to verify the targeting relationship between miR-302c and CXCL8;and the protein expressions of CXCL8, Cyclin D1, matrix metalloproteinase (MMP)-2 and MMP-9 were measured by Western blotting.

ResultsThe expression level of miR-302c in ESCC tissues was significantly lower than that in adjacent tissues (P < 0.05), when compared with the normal human esophageal epithelial cell line Het-1A, the expression level of miR-302c in human ESCC cell lines Eca109, Ec9706, TE-11, TE-10 was significantly reduced (P < 0.05), and the expression level of miR-302c was the lowest in Eca109 cells, therefore, Eca109 cells were selected for follow-up research.miR-302c targeted and negatively regulated the expression of CXCL8;up-regulating miR-302c and silencing CXCL8 could both inhibit the proliferation and invasion of Eca109 cells, and significantly reduce the protein expressions of Cyclin D1, MMP-2 and MMP-9 (P < 0.05);overexpression of CXCL8 could reverse the effect of up-regulation of miR-302c on the proliferation and invasion of Eca109 cells.

ConclusionsUp-regulating the expression of miR-302c can inhibit the proliferation and invasion of ESCC cells by targeting and inhibiting the expression of CXCL8.