Lin Dan, Lin Xiaoyang, He Tianlin, Xie Guoqun
Department of Oncology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China.
Department of Integrated TCM and Western Medicine, The First People's Hospital of Wenling, Wenling, Zhejiang, People's Republic of China.
Cancer Manag Res. 2020 Sep 28;12:9221-9233. doi: 10.2147/CMAR.S269768. eCollection 2020.
Gastric cancer (GC) is a major cancer-related mortality disease. Gambogic acid (GA) has been investigated to inhibit cancer progression. In the present study, the molecular mechanism of GA in regulating GC progression was studied.
The expression levels of circular RNA ASAP2 (circ_ASAP2), miR-33a-5p and cyclin-dependent kinases 7 () were detected by quantitative real-time polymerase reaction (qRT-PCR). protein level was evaluated by Western blot. Cell colony formation assay, 3-(4,5-Dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, transwell assay and flow cytometry analysis were employed to reveal the functional effects among circ_ASAP2, miR-33a-5p and on GA-induced GC progression. Mechanistically, the binding relationship between miR-33a-5p and circ_ASAP2 or was predicted with starBase v3.0 online database and verified by dual-luciferase reporter assay. In vivo tumor formation assay was used to explain the impacts of GA treatment on GC growth in vivo.
Circ_ASAP2 and expression were downregulated in GA-induced GC cells compared with GC cells. MiR-33a-5p expression was upregulated in GA-induced GC cells relative to GC cells. The protein expression level of was lower in GA-induced GC cells than that in GC cells. Further, circ_ASAP2 overexpression decreased GA-induced inhibition effects on cell proliferation, migration and invasion and GA-induced promotion effect on cell apoptosis in both AGS and HGC-27 cells, whereas this phenomenon was reversed by miR-33a-5p. In addition, circ_ASAP2 functioned as a sponge of miR-33a-5p and miR-33a-5p was associated with . Furthermore, GA treatment inhibited GC growth in vivo.
Circ_ASAP2 overexpression promoted cell proliferation, migration and invasion, whereas inhibited cell apoptosis by upregulating expression through binding to miR-33a-5p in GA-induced GC cells. This study provided a theoretical basis in GC treatment with GA.
胃癌（GC）是一种主要的癌症相关致死性疾病。藤黄酸（GA）已被研究用于抑制癌症进展。在本研究中，对GA调节GC进展的分子机制进行了研究。
通过定量实时聚合酶反应（qRT-PCR）检测环状RNA ASAP2（circ_ASAP2）、miR-33a-5p和细胞周期蛋白依赖性激酶7（ ）的表达水平。通过蛋白质印迹法评估蛋白质水平。采用细胞集落形成试验、3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）试验、Transwell试验和流式细胞术分析来揭示circ_ASAP2、miR-33a-5p和 对GA诱导的GC进展的功能影响。机制上，使用starBase v3.0在线数据库预测miR-33a-5p与circ_ASAP2或 之间的结合关系，并通过双荧光素酶报告基因试验进行验证。体内肿瘤形成试验用于解释GA治疗对体内GC生长的影响。
与GC细胞相比，GA诱导的GC细胞中circ_ASAP2和 的表达下调。相对于GC细胞，GA诱导的GC细胞中miR-33a-5p表达上调。GA诱导的GC细胞中 的蛋白质表达水平低于GC细胞。此外，circ_ASAP2过表达降低了GA对AGS和HGC-27细胞增殖、迁移和侵袭的抑制作用以及GA对细胞凋亡的促进作用，而miR-33a-5p可逆转这一现象。此外，circ_ASAP2充当miR-33a-5p的海绵，且miR-33a-5p与 相关。此外，GA治疗在体内抑制了GC生长。
在GA诱导的GC细胞中，circ_ASAP2过表达通过与miR-33a-5p结合上调 表达，从而促进细胞增殖、迁移和侵袭，而抑制细胞凋亡。本研究为GA治疗GC提供了理论依据。
