目的：探讨环状RNA(circRNA)circ_0000144是否靶向微小RNA(miRNA)-502-5p调控人视网膜母细胞瘤Y79细胞增殖、凋亡、迁移侵袭。

方法：将Y79细胞分为si-NC组(转染si-NC)、si-circ_0000144组(转染si-circ_0000144)、miR-NC组(转染miR-NC)、miR-502-5p组(转染miR-502-5p mimic)、pcDNA组(转染pcDNA)、pcDNA-circ_0000144组(转染pcDNA-circ_0000144)、si-circ_0000144+anti-miR-NC组(转染si-circ_0000144+anti-miR-NC)、si-circ_0000144+anti-miR-502-5p组(转染si-circ_0000144+anti-miR-502-5p)。实时定量聚合酶链反应(qRT-PCR)检测视网膜母细胞瘤组织和细胞中circ_0000144和miR-502-5p表达，溴化噻唑蓝四氮唑(MTT)检测细胞增殖，免疫印迹实验(western blot)测定细胞核相关抗原Ki-67(Ki-67)、B细胞淋巴瘤/白血病-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、基质金属蛋白酶(MMP)-2、MMP-9蛋白表达，流式细胞术分析细胞凋亡，Transwell测定细胞迁移、侵袭。生物信息学预测与双荧光素酶报告实验分析circ_0000144是否靶向miR-502-5p。

结果：31例视网膜母细胞瘤组织中circ_0000144表达量比瘤旁组织高，miR-502-5p表达量比瘤旁组织低(P<0.05)。与si-NC组比较，si-circ_0000144组Y79细胞中circ_0000144表达量、OD值、Ki-67、Bcl-2、MMP-2、MMP-9蛋白表达量、迁移、侵袭细胞数减少，Bax蛋白表达量、凋亡率增加(P<0.05)。circ_0000144靶向负调控miR-502-5p的表达。miR-502-5p组较miR-NC组增加Y79细胞凋亡率、Bax蛋白表达量，减少OD值、迁移及侵袭细胞数、Ki-67、Bcl-2、MMP-2、MMP-9蛋白表达量(P<0.05)。与si-circ_0000144+anti-miR-NC组比较，si-circ_0000144+anti-miR-502-5p组Y79细胞凋亡率、Bax蛋白表达量降低，OD值、迁移及侵袭细胞数、Ki-67、Bcl-2、MMP-2、MMP-9蛋白表达量升高。

结论：视网膜母细胞瘤组织中circ_0000144高表达，通过负调控miR-502-5p抑制其表达降低视网膜母细胞瘤Y79细胞增殖、迁移侵袭，促进凋亡。

METHODS: Y79 cells were divided into si-NC group(transfected with si-NC), si-circ_0000144 group(transfected with si-circ_0000144), miR-NC group(transfected with miR-NC), miR-502-5p group(transfected with miR-502-5p mimic), pcDNA group(transfected with pcDNA), pcDNA-circ_0000144 group(transfected with pcDNA-circ_0000144), si-circ_0000144+anti-miR-NC group(transfected with si-circ_0000144+anti-miR-NC), si-circ_0000144+anti-miR-502-5p group(transfected with si-circ_0000144+anti-miR-502-5p). Quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect the expression of circ_0000144 and miR-502-5p in retinoblastoma tissues and cells, thiazole blue tetrazolium bromide(MTT)detected cell proliferation, and western blot was employed to determine the expression of nuclear associated antigen Ki67(Ki-67), B cell lymphoma/lewkmia-2(Bcl-2), Bcl-2 associated X protein(Bax), matrix metalloprotease(MMP)-2, MMP-9 protein. Flow cytometry detected cell apoptosis, and Transwell measured cell migration and invasion. Bioinformatics prediction and dual luciferase report experiment analyzed whether circ_0000144 targets miR-502-5p.

RESULTS: The expression of circ_0000144 in 31 cases of retinoblastoma tissue was higher than that of adjacent tissues, and the expression of miR-502-5p was lower than that of adjacent tissues(P<0.05). Compared with the si-NC group, the circ_0000144 expression, OD value, expression of Ki-67, Bcl-2, MMP-2, MMP-9 protein, number of migration and invasion cells of the Y79 cells in the si-circ_0000144 group decreased, and the expression of Bax protein and apoptosis rate increased(P<0.05). circ_0000144 targets and negatively regulates the expression of miR-502-5p. Compared with miR-NC group, miR-502-5p group increased cell apoptosis rate and expression of Bax protein of the Y79 cells, while decreased OD value, number of migration and invasion cells, and the expression of Ki-67, Bcl-2, MMP-2 and MMP-9 protein(P<0.05). Compared with the si-circ_0000144+anti-miR-NC group, cell apoptosis rate and Bax protein expression of the Y79 cells in the si-circ_0000144+anti-miR-502-5p group decreased, but the OD value, number of migration and invasion cells, the protein expression of Ki-67, Bcl-2, MMP-2 and MMP-9 increased.

CONCLUSION: circ_0000144 was highly expressed in retinoblastoma tissue, and inhibiting circ_0000144 can reduce the proliferation, migration and invasion of retinoblastoma Y79 cells, and promote apoptosis through negative regulation of miR-502-5p.