[摘 要] 目的：探讨环化自erb-b2受体酪氨酸激酶2（ERBB2）基因的circ_0007766分子在前列腺癌（PCa）细胞中的作用及缺 氧对其表达调控的影响。方法：qRT-PCR检测circ_0007766分子在PCa细胞及组织中的表达；分别转染circ0007766的siRNA至 PCa细胞DU145和PC3中，平板克隆实验、CCK-8实验和Transwell 实验检测circ_0007766敲低对PCa细胞克隆形成、增殖、迁移 和侵袭能力的影响；厌氧袋法建立DU145和PC3细胞的缺氧细胞模型，WB法检测缺氧通路关键分子HIF-1α的蛋白表达， qRT-PCR 检测缺氧模型细胞中circ_0007766分子的表达，WB检测RNA结合蛋白真核翻译起始因子4A3（EIF4A3）的蛋白水平表 达，RNA免疫沉淀（RIP）法检测缺氧条件下EIF4A3与circ_0007766的结合，qRT-PCR进一步检测缺氧条件下敲低EIF4A3对 circ_0007766表达的影响。结果：circ_0007766 在 PCa 细胞（P < 0.01）及PCa组织（P < 0.05）中呈高表达；敲低circ_0007766 （P < 0.05或P < 0.01）能显著抑制PCa细胞的增殖、迁移和侵袭能力（均P < 0.01）。缺氧条件下HIF-1α蛋白表达增加，表明缺氧细 胞模型建立成功。qRT-PCR检测结果显示，相较于常氧组，缺氧组circ_0007766的表达显著升高（P < 0.01），WB法检测结果显示缺氧 组细胞中EIF4A3 的蛋白表达增强。RIP实验结果显示，circ_0007766在EIF4A3富集组高度富集（P < 0.01）。qRT-PCR检测结果显示， 缺氧可显著促进circ_0007766的表达，同时，敲低EIF4A3分子可显著降低缺氧诱导的circ_0007766的表达（P < 0.05或P < 0.01）。 结论: circ_0007766在PCa细胞中扮演着促癌分子的角色，其表达形成与缺氧条件下EIF4A3分子的调控有关。

[Abstract] Objective: To explore the role of circ_0007766 molecule cyclized from the erb-b2 receptor tyrosine kinase 2 (ERBB2) gene in prostate cancer (PCa) cells and the impact of hypoxia on the regulation of its expression. Methods: The expression of circ_0007766 molecule in PCa cells and tissues was detected by qRT-PCR. The siRNA of circ0007766 was transfected to PCa cells (DU145 cell and PC3 cell) respectively; Colony formation assay, CCK-8 assay and Transwell assay were performed to detect the effect of circ_0007766 knockdown on the colony formation, proliferation, migration, and invasion abilities of PCa cells. Hypoxia cell model of DU145 and PC3 cells were established by hypoxic chamber method, and WB was performed to detect the protein expression of HIF-1α, a key molecule of the hypoxic pathway. qRT-PCR was performed to detect the expression of circ_0007766 molecule in hypoxic cell model, and the protein expression of RNA-binding protein eukaryotic translation initiation factor 4A3 (EIF4A3) was detected by WB. RNA immunoprecipitation (RIP) was performed to detect the binding of EIF4A3 to circ_0007766 under hypoxic conditions. qRT-PCR assay was performed to further detect the effect of EIF4A3 knockdown on the expression of circ_0007766 under hypoxic conditions. Results: circ_0007766 was highly expressed in PCa cells (P < 0.01) and PCa tissues (P < 0.05). The knockdown of circ_0007766 (P < 0.05 or P < 0.01) could significantly inhibit the proliferation, migration and invasion abilities of PCa cells (all P < 0.01). The upregulation of HIF-1α protein under hypoxic conditions confirmed the successful establishment of the hypoxia cell model. qRT-PCR analysis revealed that compared with that in the normoxia group, circ_0007766 expression was markedly elevated in the hypoxia group (P < 0.01). WB analysis demonstrated increased EIF4A3 protein expression in cells of the hypoxia group. RIP assays indicated that circ_0007766 was highly concentrated in the EIF4A3-enriched group (P <0.01). Additionally, qRT-PCR showed that hypoxia significantly boosted circ_0007766 expression, whereas EIF4A3 knockdown notably diminished the hypoxia-induced expression of circ_0007766 (P < 0.05 or P < 0.01). Conclusion: Circ-0007766 plays the role of cancer-promoting molecule in PCa cells, and its expression is related to the regulation of EIF4A3 molecule under hypoxic conditions.

宁夏自然科学基金项目（No. 2024AAC03215）；宁夏医科大学2024年校级科研项目重点项目（开放课题） （No. XZ2024004）；国家自然科学基金项目（No. 82160465）