目的：探讨LINC01503 在上皮性卵巢癌（EOC）中的表达水平和生物学功能及其可能的作用机制。方法：收集2015年5月至2016 年5月间在河北医科大学第四医院妇瘤科手术切除并经病理学确诊的85 例EOC患者的肿瘤组织和输卵管组织。常规培养人EOC 细胞A2780、SKOV3、OVCAR3 和OV90 及正常人卵巢上皮细胞IOSE80，将si-LINC01503、si-NC 及miR-342-3p mimic、miR mimic NC分别转染至SKOV3和A2780 细胞，分别作为si-LINC01503 组、si-NC 组、miR-342-3p mimic 组和miR mimic NC组。qPCR 法检测EOC组织和细胞中LINC01503 的表达水平，Kaplan-Meier 法分析LINC01503 表达水平与患者生存的关系。双荧光素酶报告基因实验验证LINC01503/miR-342-3p/IGF2R轴相关分子间的靶向关系。平板克隆、划痕愈合和Transwell 实验分别检测敲低LINC01503 及转染miR-342-3p mimic 对A2780 和SKOV3细胞增殖、迁移和侵袭能力的影响。WB法检测EOC细胞中LINC01503/miR-342-3p 通路对IGF2R蛋白表达的影响。构建A2780 细胞裸鼠移植瘤模型，观察敲低LINC01503 对移植瘤生长的影响。结果：EOC组织和细胞中LINC01503 表达水平分别显著高于输卵管组织和IOSE80 细胞（均P<0.01），LINC01503高表达组患者术后PFS 和OS 均显著短于LINC01503 低表达组患者（均P<0.01）。敲低LINC01503、转染miR-342-3p mimic 均可抑制EOC 细胞的增殖、迁移和侵袭能力（均P<0.01）。敲低LINC01503 可下调IGF2R的表达（P<0.01），这一现象可通过转染miR-342-3p inhibitor 挽救。敲低LINC01503 可抑制A2780 细胞裸鼠移植瘤的生长（P<0.01）。结论：在EOC 组织和细胞中呈高表达的LINC01503，与患者的不良预后密切相关，LINC01503可能通过吸附miR-342-3p影响IGF2R表达进而促进EOC的进展。

To investigate the expression level, biological function and possible mechanism of LINC01503 in epithelial ovarian cancer (EOC). Methods: A total of 85 pairs of tumor tissues and fallopian tube tissues from EOC patients who underwent ovarian tumor reduction surgery in the Department of Gynecology, the Fourth Hospital of Hebei Medical University from May 2015 to May 2016 were collected. Human EOC cells A2780, SKOV3, OVCAR3 and OV90 and normal human ovarian epithelial cells IOSE80 were routinely cultured, and si-LINC01503, si-NC, and miR-342-3p mimic, miR mimic NC were transfected into SKOV3 and A2780 cells, respectively, and recorded as si-LINC01503 group, si-NC group, miR-342-3p mimic group and miR mimic NC group. qPCR was used to detect the expression level of LINC01503 in EOC tissues and cells, and Kaplan-Meier method was used to analyze the correlation between the expression of LINC01503 and the survival of EOC patients. Dual-luciferase reporter gene assay was used to verify the targeting relationship among melecules associated with LINC01503/miR-342-3p/IGF2R (insulin like growth factor 2 receptor) axis. The effects of LINC01503 knockdown and miR-342-3p over-expression on proliferation, migration and invasion of EOC A2780 and SKOV3 cells were detected by plate cloning assay, scratch wound healing assay and Transwell assay, respectively. The effect of LINC01503/miR-342-3p pathway on IGF2R protein expression was detected by WB method in SKOV3 and A2780 cells. A nude mouse model of A2780 cell transplanted tumor was established to observe the effect of LINC01503 on the growth of transplanted tumor. Results: The expression levels of LINC01503 in EOC tissues and cells were significantly higher than that in fallopian tube tissues and IOSE80 cells (all P<0.01). Kaplan-Meier survival analysis showed that compared with the low LINC01503 expression group, patients in the high LINC01503 expression group had significantly shorter PFS and OS after surgery (all P<0.01). Knockdown of LINC01503 and over-expression of miR-342-3p could inhibit proliferation, migration, and invasion of EOC cells (all P<0.01). WB results showed that knockdown of LINC01503 down-regulated the expression of IGF2R (P<0.01), which could be saved by transfection of miR-342-3p inhibitor (P<0.01). LINC01503 knockdown could inhibit the growth of A2780 cell transplanted tumors in vivo (P<0.01). Conclusion: LINC01503 is highly expressed in EOC tissues and cells, and it is significantly related to the poor prognosis of EOC patients. LINC01503 promotes the development of EOC possibly by upregulating IGF2R via sponging miR-342-3p.