LncRNA MEG3 inhibits proliferation and promotes apoptosis of osteosarcoma cells through regulating Notch signaling pathway

OBJECTIVE: To explore the effect of long non-coding ribonucleic acid (IncRNA)-maternally expressed gene 3 (MEG3) on the Notch signaling pathway, and its influences on the proliferation and apoptosis of osteosarcoma MG-63 cells. MATERIALS AND METHODS: LncRNA MEG3 was overexpressed in osteosarcoma MG-63 cells, and the cells were divided into Blank group, Len-con group, and Len-MEG3 group. The expression level of MEG3 in each group was detected via quantitative Polymerase Chain Reaction (qPCR), the cell proliferation level in each group was detected via Cell Counting Kit-8 (CCK-8) assay, and the apoptosis in each group was detected via Hoechst 33258 staining. Moreover, the content of the inflammatory factors in each group was determined using the Enzyme-Linked Immunosorbent Assay (ELISA), and the expression levels of apoptosis-related proteins and Notch signaling pathway-related proteins were determined through Western blotting. RESULTS: The expression level of IncRNA MEG3 in Len-MEG3 group was significantly higher than that in the Blank group and Len-con group (p<0.01). The overexpression of IncRNA MEG3 could significantly weaken the proliferation (p<0.01) and enhance the apoptosis of osteosarcoma cells (p<0.01). The overexpression of IncRNA MEG3 could significantly increase the content of the inflammatory factor interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) (p<0.01), and remarkably decrease the content of the anti-inflammatory factor IL-10 in osteosarcoma cells (p<0.01). Besides, the overexpression of IncRNA MEG3 could evidently raise the expression of Caspase3 (p<0.01) and reduce the BcI-2/Bax expression in osteosarcoma cells (p<0.01). Finally, the overexpression of IncRNA MEG3 could remarkably reduce the protein expressions of Jagged1, Notch1, and NICD1 in osteosarcoma cells (p<0.01). CONCLUSIONS: The overexpression of IncRNA MEG3 can inhibit the proliferation and promote the apoptosis of osteosarcoma MG-63 cells by suppressing the Notch signaling pathway.