Purpose: To investigate the regulation of long non-coding RNA (LncRNA) RUNX1-IT1 on microrna (mir-195)/CyclinD1 (CyclinD1) in malignant pleomorphic adenoma (MPA).
Methods: The MPA tissues and para-carcinoma tissues were collected and the expression levels of LncRNA RUNX1-IT1, miR-195 and CyclinD1 mRNA were detected, the correlation and clinical pathology of MPA was analyzed and compared. MPA cell line SM-AP1 was cultured and transfected with negative control(NC) siRNA, LncRNA RUNX1-IT1siRNA, miR-NC and miR-195 inhibitor. Cell proliferation level A490 and expression levels of miR-195 and CyclinD1 were detected. LncRNA RUNX1-IT1 targeting miR-195 and miR-195 targeting CyclinD1 were analyzed by dual luciferase reporter gene assay. SPSS 21.0 software package was used for data analysis.
Results: The expression level of LncRNA RUNX1-IT1 and CyclinD1 in MPA were higher than those in para tumor tissues, and the expression level of miR-195 was lower than that in para tumor tissues(P＜0.05). LncRNA RUNX1-IT1was negatively correlated with miR-195, positively correlated with CyclinD1, and miR-195 was negatively correlated with CyclinD1. The expression of LncRNA RUNX1-IT1 and CyclinD1 in MPA tissue with tumor diameter≥3 cm, recurrence and distant metastasis increased(P＜0.05), while the expression of miR-195 decreased(P＜0.05). After knockdown of LncRNA RUNX1-IT1, A490 level and CyclinD1 expression level decreased, while miR-195 expression level increased(P＜0.05). miR-195 decreased the fluorescence activity of LncRNA RUNX1-IT1 and CyclinD1 reporter genes(P＜0.05). After miR-195 was inhibited, the effect of LncRNA RUNX1-IT1 knockdown on decreasing A490 level and CyclinD1 expression level weakened(P＜0.05).
Conclusions: LncRNA RUNx1-IT1 may participate in the development of MPA by regulating the expression of miR-195/CyclinD1.