CircMMP11 overexpression predicts the poor survival of non-small cell lung cancer and downregulates miR-143 through methylation to suppress cell proliferation

BACKGROUND: CircMMP11 is a characterized circRNA with oncogenic function in breast cancer. In this study, we explored the involvement of circMMP11 in non-small cell lung cancer (NSCLC). METHODS: Paired cancer and non-cancer tissues were collected from 66 NSCLC patients, and the expression of circMMP11 and miR-143 in these tissues were detected using RT-qPCRs. Overexpression levels of circMMP11 and miR-143 were performed by transfection, and their crosstalk was analyzed by RT-qPCRs. The effect of circMMP11 overexpression on miR-143 methylation was analyzed by methylation-specific PCR. CCK-8 assay was performed to analyze the roles of miR-143 and circMMP11 in regulating NSCLC cell proliferation. RESULTS: We found that circMMP11 was overexpressed in NSCLC and predicted patients’ poor survival. Moreover, a close correlation between circMMP11 and miR143 was observed. In NSCLC cells, circMMP11 overexpression reduced miR-143 expression and increased miR-143 methylation. CCK-8 assay analysis showed that miR-143 reversed the enhancing effects of circMMP11 overexpression on cell proliferation. CONCLUSIONS: CircMMP11 is overexpressed in NSCLC and predicts poor survival. In addition, circMMP11 may downregulate miR-143 through methylation to suppress cell proliferation.