MST4 inhibits human hepatocellular carcinoma cell proliferation and induces cell cycle arrest via suppression of PI3K/AKT pathway
MST4 inhibits human hepatocellular carcinoma cell proliferation and induces cell cycle arrest via suppression of PI3K/AKT pathway
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MST4 通过抑制 PI3K/AKT 通路抑制人肝癌细胞增殖并诱导细胞周期停滞
DOI：
10.7150/jca.45822
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发表时间：
2020-01-01
影响因子：
3.9
通讯作者：
Jia, Jun-Shuang
中科院分区：
文献类型：
--
作者：
Hao, Wei-Chao;Zhong, Qiu-Ling;Jia, Jun-Shuang
目的：MST 4在调节细胞极性、高尔基体、细胞迁移和肿瘤等方面发挥重要作用。在机制上，它影响p-ERK、Hippo-YAP通路和自噬的活性。本研究的目的是进一步研究MST 4在肝细胞癌（HCC）中的作用及其机制。方法：采用qRT-PCR和免疫组化方法检测MST 4在肝癌及癌旁肝组织中的表达。野生型MST 4（MST 4）和MST 4的显性负突变体（dnMST 4）分别在HCC细胞系中过表达。采用CCK-8法、EdU掺入法和软琼脂法测定细胞体外增殖。采用异种移植小鼠模型来确定HCC细胞在体内的生长。PI染色和流式细胞术分析细胞周期。Western blot检测PI 3 K/AKT信号通路关键成员的表达。结果：在我们的研究中，我们报道了新的证据表明MST 4在HCC组织中频繁下调。功能获得和功能丧失实验表明，MST 4负调控体外HCC细胞增殖。此外，MST 4过表达抑制裸鼠中的Bel-7404细胞肿瘤生长。进一步的实验表明，MST 4过表达的生长抑制作用部分是由于G1期细胞周期阻滞。重要的是，机制研究表明，dnMST 4显着提高PI 3 K/AKT通路的关键成员的磷酸化水平，选择性PI 3 K抑制剂LY 294002可以逆转dnMST 4的促增殖作用。结论：总之，本研究为深入了解MST 4在肝癌中的临床意义、功能和分子机制提供了新的思路，提示MST 4在肝癌的临床治疗中可能具有潜在的治疗价值。
Objective: MST4 has exhibited functions in regulating cell polarity, Golgi apparatus, cell migration, and cancer. Mechanistically, it affects the activity of p-ERK, Hippo-YAP pathway and autophagy. The aim of this study is to further examine the functions of MST4 in hepatocellular carcinoma (HCC) and the underlying mechanism. Methods: The expression level of MST4 in HCC and noncancer adjacent liver tissues was determined by qRT-PCR and immunohistochemistry staining. Wild-type MST4 (MST4) and a dominant-negative mutant of MST4 (dnMST4) were overexpressed in HCC cell lines, respectively. CCK-8 assay, EdU incorporation assay, and soft agar assay were used to determine cell proliferation in vitro. The xenograft mouse model was employed to determine HCC cell growth in vivo. Cell cycle analysis was performed by PI staining and flow cytometry. The expression of key members in PI3K/AKT pathway was detected by Western blot analysis. Results: In our study, we reported new evidence that MST4 was frequently down-regulated in HCC tissues. Gain-of-function and loss-of-function experiments demonstrated that MST4 negatively regulated in vitro HCC cell proliferation. Additionally, MST4 overexpression suppressed Bel-7404 cell tumor growth in nude mice. Further experiments revealed that the growth-inhibitory effect of MST4 overexpression was partly due to a G1-phase cell cycle arrest. Importantly, mechanistic investigations suggested that dnMST4 significantly elevated the phosphorylation levels of key members of PI3K/AKT pathway, and the selective PI3K inhibitor LY294002 can reverse the proliferation-promoting effect of dnMST4. Conclusions: Overall, our results provide a new insight into the clinical significance, functions and molecular mechanism of MST4 in HCC, suggesting that MST4 might have a potential therapeutic value in the HCC clinical treatment.