[Long non-coding RNA RAB11B-AS1 prevents osteosarcoma proliferation via its sense gene RAB11B].

To detect the expression of lncRNA RAB11B-AS1 in osteosarcoma and investigate its role in osteosarcoma cells proliferation and the responsible mechanisms. Osteosarcoma and corresponding adjacent normal tissues were collected from 24 patients subjected to operations from October 2015 to October 2017 in the Third Affiliated Hospital of Southern Medical University.RAB11B-AS1 expression was detected in osteosarcoma specimens by quantitative real-time polymerase chain reaction (qRT-PCR). Lentiviral vectors that stably over-expressing RAB11B-AS1 were constructed and transfected into U2OS osteosarcoma cell line.The effect of RAB11B-AS1 on osteosarcoma cell proliferation and apoptosis was investigated by cell counting kit (CCK-8) assay and flow cytometry.U2OS osteosarcoma xenograft model of nude mice was established to observe the effect of RAB11B-AS1 on xenograft growth in mice, and the role of RAB11B-AS1 in proliferation and apoptosis of osteosarcoma cells was investigated by immunohistochemistry and TUNEL staining of osteosarcoma slices.The relationship between RAB11B-AS1 and RAB11B was explored using luciferase reporter assay.The data were compared with test between the two groups. Expression of RAB11B-AS1 was significantly down-regulated in osteosarcoma (0.010±0.015) versus their paired non-neoplastic tissues (0.022±0.030) (=2.117, =0.045). Up-regulation of RAB11B-AS1 resulted in decreased proliferative rate of U2OS cells (=15.659, <0.001). The ratios of cells in G0-G1 phase, S phase, G2-M phase were 62.6%±6.3%, 21.4%±2.2%, 16.3%±1.6% respectively in RAB11B-AS1 up-regulated group versus 59.4%±5.9%, 25.9%±2.6%, 15.5%±1.1% respectively in control group, and cell ratio in G0-G1 and S phase were increased significantly by RAB11B-AS1 up-regulation (=17.124, 17.321, both <0.05). Apoptosis rate was significantly elevated in RAB11B-AS1 over-expressed cells (12.7%±1.3%) when compared with that in control (10.3%±1.0%)(=17.321, =0.003). Mice transplanted with osteosarcoma cells that overexpressed RAB11B-AS1 exhibited lower growth rate of tumor (=8.798, =0.009). Mechanistically, RAB11B-AS1 expression correlated negatively with RAB11B expression (=-0.356, =0.044). lncRNA RAB11B-AS1 expression is down-regulated significantly in osteosarcoma tissues.RAB11B-AS1 may suppress the progression of osteosarcoma via down-regulating RAB11B.