Hepatitis B virus (HBV) infection is the main trigger of hepatocellular carcinoma (HCC). Circular RNA plays an indispensable role in cancer development, and this study aimed to disclose the function and mechanism of circ_0027089 in HBV-related HCC. The expression levels of circ_0027089, miR-136-5p and nucleus accumbens associated protein 1 (NACC1) mRNA were measured by quantitative real-time PCR, and the protein level of NACC1 was detected by western blot. For functional analyses, cell proliferation was assessed by cell counting kit-8 assay and colony formation assay. Cell apoptosis and cell cycle were detected by flow cytometry assay, and cell apoptosis was also assessed by caspase 3/7 activity. The capacities of migration and invasion were evaluated by wound healing assay and transwell assay, respectively. The predicted relationship between miR-136-5p and circ_0027089 or NACC1 was validated by dual-luciferase reporter assay and RNA binding protein immunoprecipitation assay. Animal experiments were performed in nude mice to explore the role of circ_0027089 in vivo. Circ_0027089 expression and NACC1 expression were elevated, while miR-136-5p expression was decreased in HBV-related HCC tissues and cells. In function, circ_0027089 knockdown inhibited HepG2.2.15 and HepAD38 (tet-off) cell proliferation, migration and invasion but induced cell cycle arrest and apoptosis, while circ_0027089 overexpression played the reversed effects. For mechanism exploration, miR-136-5p was a target of circ_0027089, and miR-136-5p deficiency could reverse the role of circ_0027089 knockdown. Circ_0027089 functioned as an oncogene to promote the development of HBV-related HCC by regulating NACC1 via competitively targeting miR-136-5p.

中文翻译：

---

Circ_0027089 通过靶向 miR-136-5p 来调节 NACC1，从而加剧乙型肝炎病毒相关肝细胞癌的发展。

乙型肝炎病毒（HBV）感染是肝细胞癌（HCC）的主要触发因素。环状RNA在癌症发生发展中发挥着不可或缺的作用，本研究旨在揭示circ_0027089在HBV相关HCC中的功能和机制。采用实时定量PCR检测circ_0027089、miR-136-5p和伏隔核相关蛋白1（NACC1）mRNA的表达水平，并采用Western blot检测NACC1的蛋白水平。对于功能分析，通过细胞计数试剂盒8测定和集落形成测定评估细胞增殖。通过流式细胞术检测细胞凋亡和细胞周期，并通过caspase 3/7活性评估细胞凋亡。分别通过伤口愈合实验和Transwell实验评估迁移和侵袭能力。通过双荧光素酶报告基因测定和 RNA 结合蛋白免疫沉淀测定验证了 miR-136-5p 和 circ_0027089 或 NACC1 之间的预测关系。采用裸鼠进行动物实验，探讨circ_0027089在体内的作用。在HBV相关的HCC组织和细胞中，Circ_0027089表达和NACC1表达升高，而miR-136-5p表达降低。在功能上，circ_0027089敲低抑制HepG2.2.15和HepAD38（tet-off）细胞增殖、迁移和侵袭，但诱导细胞周期停滞和凋亡，而circ_0027089过表达则起到相反的作用。对于机制探索，miR-136-5p是circ_0027089的靶标，miR-136-5p缺陷可以逆转circ_0027089敲低的作用。Circ_0027089 作为癌基因发挥作用，通过竞争性靶向 miR-136-5p 来调节 NACC1，从而促进 HBV 相关 HCC 的发展。