五倍子酸对60Co-γ射线辐照人肠上皮细胞的防护效应研究

目的 研究中药五倍子的有效成分五倍子酸（GA）对电离辐射诱导人肠上皮细胞（HIEC）损伤的防护作用及机制初探。方法 以4 Gy ⁶⁰Co-γ射线辐照HIEC细胞,建立细胞辐射损伤模型,采用细胞计数试剂盒-8（CCK-8）法观察不同浓度GA分别作用12、24、48 h后的细胞毒作用,以及GA对受照HIEC增殖能力的影响;平板克隆实验,观察GA对受照HIEC克隆形成能力的作用。酶联免疫吸附法（ELISA）检测GA对受照HIEC的超氧化物歧化酶（SOD）、丙二醛（MDA）、谷胱甘肽（GSH）活力的影响;Western-Blot法检测GA对受照HIEC的G1/S-特异性周期蛋白Cyclin D1和细胞周期素依赖性激酶CDK4的表达的影响,以探讨GA对受照HIEC防护作用机制。结果 研究显示：① GA作用12 h,可以促进HIEC细胞的生长（P<0.05）,但随着作用时间的延长以及GA浓度的增加,GA对HIEC细胞的生长表现出一定的毒性作用。② 4Gy的⁶⁰Co-γ射线照射下,1、10、20 μmol/L的GA预处理能显著促进HIEC的细胞克隆形成率升高（P<0.05）。③相同实验条件下,1、20 μmol/L的GA预处理能显著升高受照HIEC的细胞增殖力（P<0.05）。④同样实验条件下,1、10、20 μmol/L的GA预处理能显著升高HIEC的细胞SOD活力（P<0.05）;10 μmol/L的GA预处理能显著升高GSH活力（P<0.05）;1 μmol/L的GA预处理能显著升高细胞周期蛋白D1（Cyclin D1）和周期蛋白依赖性激酶4（CDK4）的水平（P<0.05）。结论 本实验条件下GA能一定程度上减轻⁶⁰Co-γ射线所致HIEC损伤,其作用机制可能与GA降低γ射线引起的脂质过氧化并减轻细胞周期阻滞有关。     

CDK12抑制剂在卵巢癌治疗中的研究进展

卵巢癌是死亡率最高的妇科肿瘤,其主要亚型高级浆液性卵巢癌的标准治疗模式效果欠佳,目前尚缺乏有效的临床治疗手段。细胞周期蛋白依赖性激酶（cyclin-dependent kinase, CDK）12作为CDKs中的一员,在调节基因转录、RNA剪接和DNA损伤修复等多种细胞进程中发挥重要作用。已有研究发现多种卵巢癌中存在CDK12基因突变,这些都提示了CDK12可作为潜在的治疗靶点。作者在阐述CDK12作用机制的基础上,介绍目前已发现的能够选择性抑制CDK12的试剂,并探讨CDK12抑制剂在多种类型卵巢癌中的治疗进展。     

Combined DNA repair defects in testicular metastasis from prostate cancer sensitize to immune checkpoint blockade

Testicular metastasis in prostate cancer is uncommon and may be a culprit of widespread disease which portends a worse prognosis. Little is known about the molecular biology of metastases to the testicles and whether there is any role for targeted therapeutics. Here we report a case of prostate cancer recurring with testicular and lung metastases. Targeted sequencing of the patient''s left testicular tumor after orchiectomy disclosed inactivating mutations in the CDK12 and ARID1A genes, and MSH2 and MSH6 loss resulting in high microsatellite instability and high tumor mutational burden. The patient experienced a complete radiographic and prostate-specific antigen response at 12 weeks of PD-1 immune checkpoint blockade with pembrolizumab and continues uneventfully on treatment. Molecular characterization of this rare phenotypic subtype of prostate cancer in larger studies may help deliver precision therapies with the potential to improve outcomes.     

Pharmacological evaluation and mechanistic study of compound Xishu Granule in hepatocellular carcinoma

ObjectiveIn this study, we used HepG2 human hepatocellular carcinoma cells to study the effects of Compound Xishu Granule (CXG) on cell proliferation, apoptosis, and the cell cycle in vitro. We also used a xenograft tumor model to study the anti-tumor effects of CXG and related mechanisms in vivo.MethodsThe effect of CXG on cell viability was measured using Cell Counting Kit-8 and a colony formation assay. The effect of CXG on apoptosis and the cell cycle was analyzed using flow cytometry. The in vivo anti-tumor effect of CXG was assessed by measuring the volume change in xenograft tumors after drug administration. The CXG anti-tumor mechanism was studied using western blotting assay to detect cell cycle and apoptotic associated proteins.ResultsCXG suppressed HepG2 cell proliferation in a time- and dose-dependent manner in vitro. Colony formation experiments showed that CXG administration for 24 h significantly reduced HepG2 cell formations (P < .01). Flow cytometric analysis showed that CXG treatment for 48 h promoted apoptosis and blocked HepG2 cells in the G2/M phase. Western blotting results showed that Bax was significantly up-regulated and Bcl-2 was down-regulated in graft tumor tissues and HepG2 cells after CXG administration, which increased the Bax/Bcl-2 ratio. PLK1, CDC25C, CDK1, and Cyclin B1 expression were up-regulated. CXG had a good inhibitory effect on graft tumor growth in vivo.ConclusionCXG has good anti-tumor effects in vitro and in vivo. In vitro, CXG promoted HepG2 cell apoptosis and induced G2/M phase arrest. In vivo, CXG significantly inhibited graft tumor growth. The CXG mechanism in treating hepatocellular carcinoma may be that CXG can induce abnormal apoptotic and cell cycle associated protein expression, leading to mitotic catastrophe and apoptosis.     

三氯化镧对CBRH-7919细胞CyclinD1和CDK4蛋白表达的影响

背景与目的:研究三氯化镧(LaCl3)对大鼠肝癌细胞CyclinD1和CDK4蛋白表达的影响.材料与方法:采用体外培养大鼠肝癌细胞株CBRH-7919,分别加入0.01、0.10、1.00 mmol/L LaCl3培养1、3、5 d后观察CBRH-7919细胞生长变化;运用流式细胞术、MTF实验和免疫细胞化学检测与G1期调控有关的CyclinD1和CDK4的变化情况,以培养液中不加LaCl3体外培养CBRH-7919作为对照.结果:0.10、1.00 mmol/L LaCl3组培养后3、5 d对细胞的生长均具有抑制作用,与对照组比差异具有统计学意义(P＜0.01);G0/G1期细胞百分数均有显著性增加,与对照组比差异均具有统计学意义(P＜0.01);CyclinD1、CDK4阳性表达均显著减弱,与对照组比差异具有统计学意义(P＜0.01).结论:LaCl3可通过下调CyclinD1和CDK4,使肿瘤细胞从G1期进入S期受阻,从而抑制CBRH-7919细胞的生长.     

CDK12 and HER2 coamplification in two urothelial carcinomas with rapid and aggressive clinical progression

Cyclin‐dependent kinase 12 (CDK12), one of the key factors associated with DNA damage response pathways, is located on chromosome 17 proximal to Erb‐B2 receptor tyrosine kinase 2 (ERBB2). In this report, CDK12 and ERBB2 coamplification was detected by targeted next‐generation sequencing in two urothelial carcinomas. The staining intensity of the CDK12 and human epidermal growth factor receptor‐2 proteins was associated with the prognosis of each urothelial carcinoma case. Our results suggest that CDK12 coamplification with ERBB2 might be associated with tumor aggressiveness and contribution to cancer pathogenesis. Therapies targeting CDK12 should be developed for these patients.