Background:Apolipoprotein B mRNA editing catalytic polypeptide(APOBEC),an endogenous mutator,induces DNA damage and activates the ataxia telangiectasia and Rad3-related(ATR)-checkpoint kinase 1(Chk1)pathway.Although c...Background:Apolipoprotein B mRNA editing catalytic polypeptide(APOBEC),an endogenous mutator,induces DNA damage and activates the ataxia telangiectasia and Rad3-related(ATR)-checkpoint kinase 1(Chk1)pathway.Although cisplatin-based therapy is the mainstay for muscle-invasive bladder cancer(MIBC),it has a poor survival rate.Therefore,this study aimed to evaluate the efficacy of an ATR inhibitor combined with cisplatin in the treatment of APOBEC catalytic subunit 3B(APOBEC3B)expressing MIBC.Methods:Immunohistochemical staining was performed to analyze an association between APOBEC3B and ATR in patients with MIBC.The APOBEC3B expression in MIBC cell lines was assessed using real-time polymerase chain reaction and western blot analysis.Western blot analysis was performed to confirm differences in phosphorylated Chk1(pChk1)expression according to the APOBEC3B expression.Cell viability and apoptosis analyses were performed to examine the anti-tumor activity of ATR inhibitors combined with cisplatin.Results:There was a significant association between APOBEC3B and ATR expression in the tumor tissues obtained from patients with MIBC.Cells with higher APOBEC3B expression showed higher pChk1 expression than cells expressing low APOBEC3B levels.Combination treatment of ATR inhibitor and cisplatin inhibited cell growth in MIBC cells with a higher APOBEC3B expression.Compared to cisplatin single treatment,combination treatment induced more apoptotic cell death in the cells with higher APOBEC3B expression.Conclusion:Our study shows that APOBEC3B’s higher expression status can enhance the sensitivity of MIBC to cisplatin upon ATR inhibition.This result provides new insight into appropriate patient selection for the effective application of ATR inhibitors in MIBC.展开更多
载脂蛋白B m RNA编辑酶催化多肽3F(APOBEC3F)属固有免疫系统中的重要成员,对人免疫缺陷病毒(HIV)、乙型肝炎病毒(HBV)等多种病毒的复制具有广泛的抑制作用。为构建APOBEC3F基因的真核表达载体,并检测其在体外培养的MARC145细胞中的表达...载脂蛋白B m RNA编辑酶催化多肽3F(APOBEC3F)属固有免疫系统中的重要成员,对人免疫缺陷病毒(HIV)、乙型肝炎病毒(HBV)等多种病毒的复制具有广泛的抑制作用。为构建APOBEC3F基因的真核表达载体,并检测其在体外培养的MARC145细胞中的表达情况,通过RT-PCR从猪脾脏组织扩增APOBEC3F基因,定向克隆到表达增强型绿色荧光蛋白(EGFP)的真核表达载体p EGFP-CMV中,构建p EGFP-APOBEC3F。PCR扩增及测序显示,APOBEC3F插入载体位置、方向及序列均正确。p EGFP-APOBEC3F经脂质体介导法转染MARC145细胞,转染后24 h APOBEC3F m RNA的水平升至最高。细胞免疫化学法检测发现APOBEC3F蛋白主要在MARC145细胞质中表达。研究结果为体外研究猪APOBEC3F基因在抗猪蓝耳病中的作用奠定了基础。展开更多
基金supported by St.Vincent’s Hospital,the Research Institute of Medical Science(Grant Number:SVHR-2021-03).
文摘Background:Apolipoprotein B mRNA editing catalytic polypeptide(APOBEC),an endogenous mutator,induces DNA damage and activates the ataxia telangiectasia and Rad3-related(ATR)-checkpoint kinase 1(Chk1)pathway.Although cisplatin-based therapy is the mainstay for muscle-invasive bladder cancer(MIBC),it has a poor survival rate.Therefore,this study aimed to evaluate the efficacy of an ATR inhibitor combined with cisplatin in the treatment of APOBEC catalytic subunit 3B(APOBEC3B)expressing MIBC.Methods:Immunohistochemical staining was performed to analyze an association between APOBEC3B and ATR in patients with MIBC.The APOBEC3B expression in MIBC cell lines was assessed using real-time polymerase chain reaction and western blot analysis.Western blot analysis was performed to confirm differences in phosphorylated Chk1(pChk1)expression according to the APOBEC3B expression.Cell viability and apoptosis analyses were performed to examine the anti-tumor activity of ATR inhibitors combined with cisplatin.Results:There was a significant association between APOBEC3B and ATR expression in the tumor tissues obtained from patients with MIBC.Cells with higher APOBEC3B expression showed higher pChk1 expression than cells expressing low APOBEC3B levels.Combination treatment of ATR inhibitor and cisplatin inhibited cell growth in MIBC cells with a higher APOBEC3B expression.Compared to cisplatin single treatment,combination treatment induced more apoptotic cell death in the cells with higher APOBEC3B expression.Conclusion:Our study shows that APOBEC3B’s higher expression status can enhance the sensitivity of MIBC to cisplatin upon ATR inhibition.This result provides new insight into appropriate patient selection for the effective application of ATR inhibitors in MIBC.
文摘载脂蛋白B m RNA编辑酶催化多肽3F(APOBEC3F)属固有免疫系统中的重要成员,对人免疫缺陷病毒(HIV)、乙型肝炎病毒(HBV)等多种病毒的复制具有广泛的抑制作用。为构建APOBEC3F基因的真核表达载体,并检测其在体外培养的MARC145细胞中的表达情况,通过RT-PCR从猪脾脏组织扩增APOBEC3F基因,定向克隆到表达增强型绿色荧光蛋白(EGFP)的真核表达载体p EGFP-CMV中,构建p EGFP-APOBEC3F。PCR扩增及测序显示,APOBEC3F插入载体位置、方向及序列均正确。p EGFP-APOBEC3F经脂质体介导法转染MARC145细胞,转染后24 h APOBEC3F m RNA的水平升至最高。细胞免疫化学法检测发现APOBEC3F蛋白主要在MARC145细胞质中表达。研究结果为体外研究猪APOBEC3F基因在抗猪蓝耳病中的作用奠定了基础。
