Statin as a therapeutic agent in gastroenterological cancer

Statins inhibit 3-hydroxy-3-methylglutaryl-CoA reductase, the rate-limiting enzyme of the mevalonate pathway, and are widely used as an effective and safe approach handle hypercholesterolemia. The mevalonate pathway is a vital metabolic pathway that uses acetyl-CoA to generate isoprenoids and sterols that are crucial to tumor growth and progression. Multiple studies have indicated that statins improve patient prognosis in various carcinomas. Basic research on the mechanisms underlying the antitumor effects of statins is underway. The development of new anti-cancer drugs is progressing, but increasing medical costs from drug development have become a major obstacle. Readily available, inexpensive and well-tolerated drugs like statins have not yet been successfully repurposed for cancer treatment. Identifying the cancer patients that may benefit from statins is key to improved patient treatment. This review summarizes recent advances in statin research in cancer and suggests important considerations for the clinical use of statins to improve outcomes for cancer patients.     

GCDH^-/-大鼠海马氧化应激损伤机制研究

目的探讨高赖氨酸饮食的戊二酰辅酶A脱氢酶(GCDH)基因缺陷(GCDH^-/-)大鼠氧化应激损伤机制及可能通路。方法4周龄雄性SD大鼠按照随机数字表法分为6组:野生型标准饮食(WT)组(n=6)、纯合子标准饮食(GCDH^-/-)组(n=11)、野生型高赖氨酸(WT+Lys)组(n=8)、纯合子高赖氨酸(GCDH^-/-+Lys)组(n=13)、野生型高赖氨酸加维生素E(WT+Lys+VE)组(n=7)、纯合子高赖氨酸加维生素E(GCDH^-/-+Lys+VE)组(n=12)。WT组和GCDH^-/-组给予标准饮食(常规大鼠饲料),余4组给予4.7%高赖氨酸加强饲料,自由进食水。WT+Lys+VE和GCDH^-/-+Lys+VE组于每天上午10点维生素E[100 mg/(kg·d)]灌胃1次,其余各组等量生理盐水灌胃。观察各组大鼠体质量及存活情况。干预28 d后腹腔注射100 g/L水合氯醛麻醉后断头取脑获取海马组织,通过HE染色观察大鼠海马病理形态学改变;ELISA法检测海马氧化应激指标谷胱甘肽过氧化物酶(GPx)、丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽(GSH)含量/活性;Western blotting实验检测海马P38、c-Jun N-氨基端激酶(JNK)、细胞外调节蛋白激酶(ERK)蛋白表达情况。结果(1)一般情况:GCDH^-/-+Lys组大鼠存活比例为9/13,GCDH^-/-+Lys+VE组大鼠为11/12。干预第7天开始,GCDH^-/-+Lys组、GCDH^-/-+Lys+VE组大鼠体质量均显著低于WT组,差异有统计学意义(P<0.05)。(2)应激指标检测结果:与WT组相比,GCDH^-/-+Lys组和GCDH^-/-+Lys+VE组大鼠海马组织MDA含量显著增加,差异有统计学意义(P<0.05)。与WT组比较,GCDH^-/-+Lys组大鼠GPx活性、CAT活性、SOD活性显著减弱,GSH含量显著减少,差异有统计学意义(P<0.05);与GCDH^-/-+Lys组比较,GCDH^-/-+Lys+VE组大鼠GPx活性、CAT活性、SOD活性显著增强,GSH含量显著增加,差异有统计学意义(P<0.05)。(3)Western blotting实验结果:与WT组比较,GCDH^-/-+Lys组和GCDH^-/-+Lys+VE组大鼠海马P38蛋白表达显著增加,差异有统计学意义(P<0.05);与GCDH^-/-+Lys组比较,GCDH^-/-+Lys+VE组P38蛋白表达减少,差异有统计学意义(P<0.05)。结论高赖氨酸饮食GCDH^-/-大鼠海马存在氧化应激损伤,其可能机制与激活P38启动丝裂原活化蛋白激酶信号通路有关;维生素E可降低P38表达,减轻氧化应激损伤。     

微生物来源的胆固醇酰基转移酶抑制剂研究.菌株分类、发酵、分离和生物学特性

用大鼠肝微粒体酶系统筛选脂酰辅酶 A:胆固醇酰基转移酶 (ACAT)抑制剂 ,获得了一株阳性菌株 ,经初步分类鉴定为 Aspergillussp.H717。曲霉 H717的发酵液经溶媒提取 ,硅胶柱层析 ,葡聚糖 L H- 2 0凝胶柱层析和反相中压液相柱层析得到两个活性化合物 NA- 2 0 9A、B。用大鼠肝微粒体酶系统测定其 IC5 0 分别为 6 0 .6和 86 .7μmol/ L。     

Association between statin use and all-cause mortality in cancer survivors,based on the Korean health insurance service between 2002 and 2015

Background and aimsCancer is the number one cause of death in Korea. This study aimed to investigate if statin use in cancer survivors was inversely associated with all-cause mortality.Methods and resultsData from the 2002 to 2015 National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) were used. The Kaplan–Meier estimator was used to estimate the survival function according to statin usage. Cox proportional hazards regression models were adopted after stepwise adjustment for potential confounders to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality. The median follow-up duration was 10.0 years. Statin users had a higher percentage of diabetes and hypertension in both sexes. Survival rates of statin users were higher than non-users (p-values <0.001 in men and 0.021 in women). Compared to non-users, the HRs (95% CIs) of statin users for all-cause mortality were 0.327 (0.194–0.553) in men and 0.287 (0.148–0.560) in women after adjustment for potential confounding factors.ConclusionsStatin users in cancer survivors had higher survival rate than non-users in both sexes.     

Impaired expression of acyl-CoA synthetase 5 in sporadic colorectal adenocarcinomas

Several pathways of fatty acid metabolism have been shown to be associated with the pathogenesis of colorectal cancer. Fatty acid acyl-CoA thioesters are formed from free fatty acids and coenzyme A by the activity of acyl-CoA synthetases (ACSs). Whilst an increase in ACS4 expression has been associated with colorectal carcinogenesis, little is known about possible pathogenetic functions of other ACS isoforms, such as ACS5, in tumourigenesis. In the present study, gene expression, protein synthesis, and enzymatic activity of ACS5 in sporadic colorectal adenocarcinomas, adenomas, and established cell lines were analysed using RT-PCR, western blot analysis, immunofluorescence, and an enzymatic assay. Enhanced expression of ACS5 mRNA and protein as well as enzymatic activity was found in adenomas and in 11 (73%; group 1) of 15 colorectal adenocarcinomas investigated, while a decrease of ACS5 was seen in four tumours (27%; group 2). However, basal ACS5 enzymatic activity was increased as a percentage of the total activity of ACSs in both groups, arguing for an absolute (group 1) or relative (group 2) increase in ACS5 enzymatic activity in all adenocarcinomas investigated. These findings are reflected by in vitro analysis of three established colorectal adenocarcinoma cell lines, in which activity of ACS5 occurred. The results suggest the involvement of ACS5 in the early genesis of colorectal cancer, most likely by modification of the transport and pool formation of long-chain acyl-CoA thioesters, as recently demonstrated for other isoforms of the ACS family.     

Severe holocarboxylase synthetase deficiency with incomplete biotin responsiveness resulting in antenatal insult in samoan neonates

We describe 7 Polynesian babies with a unique severe form of holocarboxylase synthetase deficiency characterized by antenatal growth retardation, subependymal cysts, only partial response to biotin, and a poor outcome.     

Robotic inhibition assay for determination of HMG-CoA reductase inhibitors in human plasma

The cholesterol-lowering drug simvastatin (SIMV, Zocor reduced heart attacks by 42% in patients who had high cholesterol levels and suffered from heart disease. Upon oral administration, SIMV is quickly hydrolyzed to its beta-hydroxyacid and other acid metabolites, which are potent inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase. A Tecan-based enzyme inhibition assay has been developed to improve the existing Zymark-based assay for the determination of both active and total concentrations of HMG-CoA reductase inhibitors in human plasma. A Tecan Genesis 200 robotic workstation equipped with eight probes and customized hardware was utilized to achieve higher sample throughput and improve assay reproducibility and mechanical stability. The developed enzyme inhibition assay was validated over two concentration ranges of 0.4-20 ng equivalent/mL, and 2-50 ng equivalent/mL. Intra- and interday precision data (coefficient of variation (CV)) for both concentration ranges were less than 9%, with an accuracy of 93-107%. The interday precision for the determination of quality control (QC) samples was less than 2% and 8%, respectively. The respective interday QC accuracy values were 93-103% and 97-104%. Good linearity across the two concentration ranges was observed, with acceptable reproducibility. This improved enzyme inhibition assay has been utilized to analyze human plasma samples from several clinical studies.