Background:Magnesium cantharidate(MC)is a protein phosphatase 2A(PP2A)inhibitor antitumor drug.However,its antitumor mechanism in hepatocellular carcinoma cell(HCC)remains unclear.Methods:PP2A lentiviral vector over e...Background:Magnesium cantharidate(MC)is a protein phosphatase 2A(PP2A)inhibitor antitumor drug.However,its antitumor mechanism in hepatocellular carcinoma cell(HCC)remains unclear.Methods:PP2A lentiviral vector over expression strategy was utilized both in vivo and in vitro to explore the antitumor effect in MC and okadaic acid(OA).Tumor weight was detected in mice after MC and OA exposure.Cell proliferation,cell cycle,apoptosis rate,and western blotting were detected to explore the effects on MC and OA in human hepatocarcinoma SMMC-7721 cells.Results:In vivo results demonstrated that MC inhibited HCC progression while OA promoted tumor growth.In vitro results demonstrated that MC effectively inhibited the growth of SMMC-7721 cells by arresting the cell cycle at the G2/M phase with inhibiting Cdc25C and activating the phosphorylation of the Cdc2 protein.Flow cytometry results further showed that MC increased apoptosis.Furthermore,the expression of phosphorylated ERK1/2 was lower in the MC group but higher in the OA group.Molecular docking results showed that MC docked well with ERK1/2.Conclusions:MC inhibited HCC progression by suppressing the growth and activating the apoptosis of cancer cells and suppressing the expression of PP2A and ERK1/2.展开更多
蛋白磷酸酶2A(PP2A)是由36 k Da的催化亚基C(PP2Ac)和65 k Da的结构亚基A(PP2Aα/β)一起组成PP2A的核心酶,并且和各种不同的调节亚基B形成具有不同功能的PP2A全酶复合体。在细胞中PP2A发挥着重要作用,特别是在抑制肿瘤的形成当中,编码P...蛋白磷酸酶2A(PP2A)是由36 k Da的催化亚基C(PP2Ac)和65 k Da的结构亚基A(PP2Aα/β)一起组成PP2A的核心酶,并且和各种不同的调节亚基B形成具有不同功能的PP2A全酶复合体。在细胞中PP2A发挥着重要作用,特别是在抑制肿瘤的形成当中,编码PP2Aα/β基因的突变将导致肿瘤的形成和其他疾病。当非小细胞肺癌细胞H1299中过表达PP2A-Aα时,细胞生长被抑制,细胞周期停留在G0/G1期,致瘤能力也同时被抑制。进一步研究证明当PP2A-Aα过表达时,Akt被去磷酸化失活使Skp2的表达下调,从而导致细胞周期抑制因子p27kip1的表达上调。肿瘤细胞软琼脂克隆形成实验的结果表明过表达PP2A-Aα之后H1299细胞的锚定非依赖性生长能力明显的降低,形成的克隆细胞团也较小,这些结果和裸鼠成瘤实验的结果是一致的。展开更多
基金The research was financially supported by the National Natural Science Foundation of China(no.81760746)Science and Technology Department of Zunyi city of Guizhou province of China([2020]7)Guizhou Provincial Science&Technology Program(ZK[2022]615).
文摘Background:Magnesium cantharidate(MC)is a protein phosphatase 2A(PP2A)inhibitor antitumor drug.However,its antitumor mechanism in hepatocellular carcinoma cell(HCC)remains unclear.Methods:PP2A lentiviral vector over expression strategy was utilized both in vivo and in vitro to explore the antitumor effect in MC and okadaic acid(OA).Tumor weight was detected in mice after MC and OA exposure.Cell proliferation,cell cycle,apoptosis rate,and western blotting were detected to explore the effects on MC and OA in human hepatocarcinoma SMMC-7721 cells.Results:In vivo results demonstrated that MC inhibited HCC progression while OA promoted tumor growth.In vitro results demonstrated that MC effectively inhibited the growth of SMMC-7721 cells by arresting the cell cycle at the G2/M phase with inhibiting Cdc25C and activating the phosphorylation of the Cdc2 protein.Flow cytometry results further showed that MC increased apoptosis.Furthermore,the expression of phosphorylated ERK1/2 was lower in the MC group but higher in the OA group.Molecular docking results showed that MC docked well with ERK1/2.Conclusions:MC inhibited HCC progression by suppressing the growth and activating the apoptosis of cancer cells and suppressing the expression of PP2A and ERK1/2.
文摘蛋白磷酸酶2A(PP2A)是由36 k Da的催化亚基C(PP2Ac)和65 k Da的结构亚基A(PP2Aα/β)一起组成PP2A的核心酶,并且和各种不同的调节亚基B形成具有不同功能的PP2A全酶复合体。在细胞中PP2A发挥着重要作用,特别是在抑制肿瘤的形成当中,编码PP2Aα/β基因的突变将导致肿瘤的形成和其他疾病。当非小细胞肺癌细胞H1299中过表达PP2A-Aα时,细胞生长被抑制,细胞周期停留在G0/G1期,致瘤能力也同时被抑制。进一步研究证明当PP2A-Aα过表达时,Akt被去磷酸化失活使Skp2的表达下调,从而导致细胞周期抑制因子p27kip1的表达上调。肿瘤细胞软琼脂克隆形成实验的结果表明过表达PP2A-Aα之后H1299细胞的锚定非依赖性生长能力明显的降低,形成的克隆细胞团也较小,这些结果和裸鼠成瘤实验的结果是一致的。
