FOXO3 Inhibits Human Gastric Adenocarcinoma (AGS) Cell Growth by Promoting Autophagy in an Acidic Microenvironment
FOXO3 Inhibits Human Gastric Adenocarcinoma (AGS) Cell Growth by Promoting Autophagy in an Acidic Microenvironment
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FOXO3 通过促进酸性微环境中的自噬来抑制人胃腺癌 (AGS) 细胞生长
DOI：
10.1159/000492884
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发表时间：
2018-01-01
影响因子：
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通讯作者：
Liu, Shihai
中科院分区：
文献类型：
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作者：
Gao, Yuan;Qi, Weiwei;Liu, Shihai
背景/目的：以前的研究表明FOXO 3，叉头盒O（FOXO）家族的成员，调节各种细胞中的自噬。迄今为止，胃癌（GC）细胞中自噬的诱导是否由酸性微环境触发尚不清楚。FOXO 3与GC中酸性微环境的关系知之甚少。本研究的目的是研究FOXO 3和酸性微环境在自噬中的作用，并确定FOXO 3和酸性微环境如何通过自噬调节GC细胞生长。研究方法：将人胃腺癌（AGS）细胞置于不同pH值的培养液中培养，用FOXO 3a质粒转染AGS细胞，检测不同pH值培养液中AGS细胞的自噬情况。此外，我们还进行了细胞计数试剂盒8（CCK 8），伤口和细胞侵袭试验，分别测试细胞活力和侵袭。我们采用实时荧光定量PCR、蛋白质印迹和mRFP-GFP-LC 3载体检测各种自噬指标的表达。结果：我们发现，与对照细胞相比，用FOXO 3处理并暴露于酸性微环境的细胞显示出生长抑制。我们还发现，在酸性微环境中培养的FOXO 3质粒转染的AGS细胞中，几种自噬标记物如LC 3 I、LC 3 II和Beclin-1的蛋白表达水平高于对照细胞，而P62蛋白表达水平在FOXO 3质粒转染的细胞中明显低于对照细胞。此外，我们观察到自噬通量在AGS细胞过表达FOXO 3和暴露于低pH条件。结论：FOXO 3在酸性微环境中通过促进自噬抑制AGS细胞生长。此外，结果表明，靶向FOXO 3和低pH条件的抗癌疗法可能有助于治疗GC。
Background/Aims: Previous studies have shown that FOXO3, a member of the forkhead box O (FOXO) family, regulates autophagy in various cells. To date, whether the induction of autophagy in gastric cancer (GC) cells is triggered by an acidic microenvironment is unclear. Little is known about the relationship between FOXO3 and acidic microenvironments in GC. The aims of our study were to investigate the roles of FOXO3 and the acidic microenvironment in autophagy and to determine how FOXO3 and the acidic microenvironment regulate GC cell growth through autophagy. Methods: We cultured human gastric adenocarcinoma (AGS) cells in media with different pH values in vitro, transfected the cells with FOXO3a plasmids and then detected autophagy in the cells under different conditions. In addition, we also performed cell counting kit 8 (CCK8), wound and cell invasion assays to test cell viability and invasion, respectively. We employed real-time PCR, western blotting and mRFP-GFP-LC3 vectors to detect the expression of various autophagy indicators. Results: We found that cells treated with FOXO3 and exposed to an acidic microenvironment displayed suppressed growth compared with control cells. We also found that the protein expression levels of several autophagy makers, such as LC3I, LC3II and Beclin-1, were higher in FOXO3 plasmid-transfected AGS cells cultured in an acidic microenvironment than in control cells, while P62 protein expression levels were clearly decreased in FOXO3 plasmid-transfected cells compared with control cells. Moreover, we observed autophagic flux in AGS cells overexpressing FOXO3 and exposed to low pH conditions. Conclusion: These findings suggest that FOXO3 inhibits AGS cell growth by promoting autophagy in an acidic microenvironment. Furthermore, the results showed that anticancer therapies targeting FOXO3 and low pH conditions may be useful in the treatment of GC.