Abstract

Purpose

Curcumin has shown anti-tumor activity in multiple malignancies. The aim of our study was to explore the molecular mechanism behind the anti-tumor activity of curcumin in hepatocellular carcinoma (HCC).

Methods

The proliferation, migration, invasion, and apoptosis were analyzed by 5-ethynyl-2′-deoxyuridine (EDU) assay, transwell migration assay, transwell invasion assay, and flow cytometry. Western blot assay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were conducted to analyze protein and RNA expression. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay, and RNA-pull down assay were performed to confirm the interaction between microRNA-378b (miR-378b) and circular RNA_0078710 (circ_0078710) or DNA primase, polypeptide 2 (PRIM2). Tumor xenograft assay was conducted to assess the roles of curcumin and circ_0078710 in vivo.

Results

Curcumin stimulation restrained the proliferation, migration, and invasion, and triggered the apoptosis of HCC cells. Curcumin down-regulated the expression of circ_0078710 in HCC cells in a dose-dependent manner. Circ_0078710 knockdown aggravated curcumin-mediated anti-tumor effects in HCC cells. Circ_0078710 acted as a molecular sponge for miR-378b. Circ_0078710 interference-induced effects in curcumin-stimulated HCC cells were partly abolished by the silence of miR-378b. MiR-378b bound to the 3′ untranslated region (3′UTR) of PRIM2. PRIM2 overexpression partly reversed circ_0078710 interference-mediated influences in curcumin-treated HCC cells. Circ_0078710 silencing aggravated curcumin-mediated suppressive effect in tumor growth in vivo.

Conclusions

Circ_0078710 silencing aggravated curcumin-mediated anti-tumor effects through mediating the miR-378b/PRIM2 signaling in HCC cells.

中文翻译：

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姜黄素通过调节 circ_0078710/miR-378b/PRIM2 轴来抑制肝细胞癌的进展

摘要

目的

姜黄素在多种恶性肿瘤中显示出抗肿瘤活性。我们研究的目的是探讨姜黄素在肝细胞癌 (HCC) 中的抗肿瘤活性背后的分子机制。

方法

通过5-乙炔基-2'-脱氧尿苷（EDU）测定、transwell迁移测定、transwell侵袭测定和流式细胞术分析增殖、迁移、侵袭和凋亡。进行蛋白质印迹分析和逆转录定量聚合酶链反应 (RT-qPCR) 以分析蛋白质和 RNA 表达。进行双荧光素酶报告基因测定、RNA 免疫沉淀 (RIP) 测定和 RNA 下拉测定以确认 microRNA-378b (miR-378b) 与环状 RNA_0078710 (circ_0078710) 或 DNA 引物酶多肽 2 (PRIM2) 之间的相互作用。进行肿瘤异种移植试验以评估姜黄素和 circ_0078710在体内的作用。

结果

姜黄素刺激抑制了肝癌细胞的增殖、迁移和侵袭，并引发了肝癌细胞的凋亡。姜黄素以剂量依赖性方式下调 HCC 细胞中 circ_0078710 的表达。Circ_0078710 敲低加重了姜黄素介导的 HCC 细胞中的抗肿瘤作用。Circ_0078710 充当 miR-378b 的分子海绵。miR-378b 的沉默部分消除了 Circ_0078710 干扰诱导的姜黄素刺激 HCC 细胞的作用。MiR-378b 与 PRIM2 的 3' 非翻译区 (3'UTR) 结合。PRIM2 过表达部分逆转了 circ_0078710 干扰介导的姜黄素处理 HCC 细胞的影响。Circ_0078710 沉默加剧了姜黄素介导的体内肿瘤生长抑制作用。

结论

Circ_0078710 通过介导 HCC 细胞中的 miR-378b/PRIM2 信号传导沉默加重姜黄素介导的抗肿瘤作用。