Objective: To detect the expression of lncRNA RAB11B-AS1 in osteosarcoma and investigate its role in osteosarcoma cells proliferation and the responsible mechanisms. Methods: 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 t test between the two groups. Results: Expression of RAB11B-AS1 was significantly down-regulated in osteosarcoma (0.010±0.015) versus their paired non-neoplastic tissues (0.022±0.030) (t=2.117, P=0.045). Up-regulation of RAB11B-AS1 resulted in decreased proliferative rate of U2OS cells (F=15.659, P<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 (t=17.124, 17.321, both P<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%)(t=17.321, P=0.003). Mice transplanted with osteosarcoma cells that overexpressed RAB11B-AS1 exhibited lower growth rate of tumor (F=8.798, P=0.009). Mechanistically, RAB11B-AS1 expression correlated negatively with RAB11B expression (r=-0.356, P=0.044). Conclusions: lncRNA RAB11B-AS1 expression is down-regulated significantly in osteosarcoma tissues.RAB11B-AS1 may suppress the progression of osteosarcoma via down-regulating RAB11B.
目的： 探讨长链非编码RNA(lncRNA)RAB11B-AS1在骨肉瘤中的表达及其对骨肉瘤细胞增殖的影响及其作用机制。 方法： 采用2015年10月至2017年10月南方医科大学第三附属医院24对骨肉瘤组织及癌旁正常组织，用实时荧光定量PCR检测组织中RAB11B-AS1的表达水平。用慢病毒载体构建稳定过表达RAB11B-AS1的骨肉瘤细胞，细胞计数试剂盒(CCK-8)和流式细胞技术检测RAB11B-AS1对骨肉瘤细胞增殖、凋亡的影响。建立裸鼠移植瘤模型，观察RAB11B-AS1对裸鼠移植瘤生长的影响。免疫组化和TUNEL实验检测RAB11B-AS1对骨肉瘤细胞体内增殖和凋亡的影响。荧光素酶报告基因探究RAB11B-AS1与RAB11B的关联。两组均数比较采用t检验。 结果： 骨肉瘤组织与癌旁组织的RAB11B-AS1相对表达量分别为0.010±0.015、0.022±0.030，差异有统计学意义(t＝2.117，P＝0.045)。过表达组肿瘤细胞增殖率变化幅度显著低于对照组(F＝15.659，P<0.001)。流式细胞术显示过表达组细胞处于G0～G1期、S期、G2-M期的比例分别为62.6%±6.3%、21.4%±2.2%、16.3%±1.6%，而对照组则分别为59.4%±5.9%、25.9%±2.6%、15.5%±1.1%，其中两组细胞处于G0～G1期、S期的比例差异有统计学意义(t＝17.124、17.321，均P<0.05)；过表达组与对照组的肿瘤细胞凋亡率分别为12.7%±1.3%和10.3%±1.0%(t＝17.321，P＝0.003)。裸鼠成瘤显示过表达组的肿瘤生长慢于对照组(F＝8.798, P＝0.009)。RAB11B-AS1在骨肉瘤组织的表达与RAB11B表达呈负相关(r＝－0.356，P＝0.044)。 结论： lncRNA RAB11B-AS1在骨肉瘤组织中低表达，且其过表达可通过降低RAB11B的表达进而抑制骨肉瘤的发生发展。.
Keywords: Gene RAB11B; Long non-coding RNA; Osteosarcoma; Proliferation.