Daptomycin resistant Enterococcus faecalis has a mutation in liaX,which encodes a surface protein that inhibits the LiaFSR systems and cell membrane remodeling

The emergence of daptomycin (DAP) resistant Enterococcus species has increased worldwide, but the mechanisms for DAP resistance are not fully understood. We report a case of DAP resistant Enterococcus faecalis, from a clinical sample of a patient with diabetic ulcers, after DAP therapy. Whole-genome sequencing analysis revealed that the isolate had a loss-of-function point mutation within liaX encoding DAP-sensing surface protein, which inhibits the LiaFSR systems and cell membrane remodeling. This is the first case report of a clinical DAP resistant E. faecalis with a mutation in liaX.     

转录共激活子TAZ对肝癌细胞株MHCC97H增殖能力的影响

目的 观察转录共激活子TAZ对肝癌细胞株MHCC97H的增殖能力的影响,以期对阐明原发性肝细胞癌(HCC)的发生发展机制提供1个新的研究思路.方法 应用细胞转染、RNA干扰(RNAi)以及过表达技术,在肝癌细胞株MHCC97H中干预TAZ的表达.在转染后提取细胞RNA和总蛋白,应用qRT-PCR和Western blot等方法检测TAZ、Nek7的表达.选用细胞计数kit-8(CCK-8)法检测细胞活性和增殖能力.结果 与NC组相比,转染了TAZ特异性靶向干扰片段之后,TAZ的mRNA与蛋白表达水平均出现下调,差异具有统计学意义(P＜0.0001);Nek7表达也出现下降,差异具有统计学意义(P＜0.0001);功能实验(CKK8)发现MHCC97H细胞活性和增殖能力也降低,差异具有统计学意义(P＜0.001).另一方面,过表达了TAZ之后,Nek7表达水平也相应上调了,差异具有统计学意义(P＜0.0001);MHCC97H细胞活性和增殖能力也提高,差异具有统计学意义(P＜0.001).结论 转录共激活子TAZ能通过调控Nek7的表达对肝癌细胞MHCC97H的增殖能力产生影响,该发现对于阐明TAZ在肝癌发生发展过程中的作用提供一定的实验基础.     

食管鳞癌组织中TAZ和Lats2的表达及其临床意义

目的 探讨TAZ、Lats2在食管鳞癌组织中的表达情况,并分析其与临床病理特征及预后的关系。方法MaxVision免疫组织化学法检测145例食管鳞癌组织和39例癌旁组织中TAZ与Lats2的表达,并分析两者表达与临床病理特征和预后的关系。结果TAZ在食管鳞癌组织与癌旁组织中的高表达率分别为58.6％（85／145）和38.5％（15／39）,差异有统计学意义（P＜0.05）,且TAZ的表达与肿瘤浸润深度、淋巴结转移、组织学分级、肿瘤直径及pTNM分期有关（P＜0.05）。Lats2在食管鳞癌组织中的高表达率为45.5％（66／145）,低于癌旁组织的64.1％（25／39）,差异有统计学意义（P＜0.05）,且Lats2的表达与肿瘤浸润深度、淋巴结转移及pTNM分期有关（P＜0.05）。TAZ与Lats2在食管鳞癌组织中的表达呈负相关（r=-0.272,P=0.001）。TAZ高表达者的中位总生存时间（OS）和无进展生存时间（PFS）分别为30个月和20个月,均低于低表达者的59个月和57个月（P均＜0.001）;Lats2高表达者的中位OS和PFS分别为42个月和33个月,均高于低表达者的32个月和18个月（P=0.035,P=0.019）。结论 TAZ、Lats2可能与食管鳞癌的发生、发展有关,对两者的检测可能对指导食管鳞癌的治疗及预后评估有重要意义。     

结直肠癌中TAZ和β-catenin的表达及意义

目的：观察TAZ和β-catenin蛋白在结直肠癌中的表达,探讨二者与结直肠癌发生、发展的关系。方法应用免疫组化EnVision两步法检测168例结直肠癌组织和30例正常肠黏膜组织中TAZ和β-catenin的表达。结果结直肠癌组织中TAZ的阳性率显著高于正常肠黏膜组织(P<0．01),其表达与病理学分级、浸润深度、淋巴结转移、TNM分期相关(P<0．05),TAZ阳性组的5年生存率显著低于TAZ阴性组( P<0．05);结直肠癌组织中β-catenin异常表达率显著高于正常肠黏膜组织( P<0．01),其异常表达与肿瘤浸润深度、淋巴结转移、TNM分期相关(P<0．05);β-catenin异常表达组的5年生存率显著低于β-catenin正常表达组(P<0．05);结直肠癌中TAZ阳性表达和β-catenin异常表达呈正相关(P<0．01)。结论 TAZ表达增高和β-catenin异常表达在结直肠癌发生、发展中具有重要作用,检测TAZ和β-catenin的表达可作为判断结直肠癌的生物学行为和判断预后的指标。     

CD44v8-10 is a marker for malignant traits and a potential driver of bone metastasis in a subpopulation of prostate cancer cells

Objective:Bone metastasis is a clinically important outcome of prostate carcinoma (PC). We focused on the phenotypic and functional characterization of a particularly aggressive phenotype within the androgen-independent bone metastasis-derived PC3 cell line. These cells, originated from the spontaneous conversion of a CD44-negative subpopulation, stably express the CD44v8-10 isoform (CD44v8-10^pos) and display stem cell-like features and a marked invasive phenotype in vitro that is lost upon CD44v8-10 silencing.Methods:Flow cytometry, enzyme-linked immunoassay, immunofluorescence, and Western blot were used for phenotypic and immunologic characterization. Real-time quantitative polymerase chain reaction and functional assays were used to assess osteomimicry.Results:Analysis of epithelial–mesenchymal transition markers showed that CD44v8-10^pos PC3 cells surprisingly display epithelial phenotype and can undergo osteomimicry, acquiring bone cell phenotypic and behavioral traits. Use of specific siRNA evidenced the ability of CD44v8-10 variant to confer osteomimetic features, hence the potential to form bone-specific metastasis. Moreover, the ability of tumors to activate immunosuppressive mechanisms which counteract effective immune responses is a sign of the aggressiveness of a tumor. Here we report that CD44v8-10^pos cells express programmed death ligand 1, a negative regulator of anticancer immunity, and secrete exceptionally high amounts of interleukin-6, favoring osteoclastogenesis and immunosuppression in bone microenvironment. Notably, we identified a novel pathway activated by CD44v8-10, involving tafazzin (TAZ) and likely the Wnt/TAZ axis, known to play a role in upregulating osteomimetic genes.Conclusions:CD44v8-10 could represent a marker of a more aggressive bone metastatic PC population exerting a driver role in osteomimicry in bone. A novel link between TAZ and CD44v8-10 is also shown.     

结直肠癌患者外周血与肿瘤组织中TAZ表达的关系及临床意义研究

目的 探讨转录共激活因子(TAZ)在结直肠癌患者外周血与肿瘤组织中表达,分析其关系及临床意义.方法 选取经病理确诊为结直肠癌并行根治性手术患者85例为手术组,手术后确诊复发的患者35例作为复发组,同时选取年龄性别相匹配的健康人50例为对照组.取结直肠癌患者肿瘤组织及正常黏膜组织石蜡标本,采用免疫组织化学染色检测TAZ表达,酶联免疫吸附试验(ELISA)检测各组外周血中TAZ的水平.结果 手术组患者术前外周血中TAZ水平明显高于对照组(P＜005),手术后TAZ水平较对照组无明显变化(P＞0.05),复发组患者外周血TAZ水平明显高于手术组术前(P＜0.05).手术组患者肿瘤组织中TAZ表达明显高于正常黏膜组织(P＜0.05),复发组患者肿瘤组织中TAZ表达高于手术组(P＜0.05).手术组和复发组患者肿瘤组织与外周血TAZ水平呈正相关性(P＜0.05).结论 监测TAZ水平对及时了解肿瘤复发有明显的参考价值.     

Regulatory role of microRNAs in cancer through Hippo signaling pathway

Cancer is the major cause of death worldwide in countries of all income levels. The Hippo signaling pathway is a Drosophila kinase gene that was identified to regulate organ size, cell regeneration, and contribute to tumorigenesis. A huge variety of extrinsic and intrinsic signals regulate the Hippo signaling pathway. The Hippo signaling pathway consists of a wide array of components that merge numerous signals such as mechanical signals to address apoptosis resistance, cell proliferation, cellular outputs of growth, cell death and survival at cellular and tissue level. Recent studies have shed new light on the regulatory role of microRNAs in Hippo signaling and how they contribute to cancer progression. MicroRNAs influence various cancer-related processes such as, apoptosis, proliferation, migration, cell cycle and metabolism. Inhibition and overexpression of miRNAs via miRNA mimics and miRNA inhibitors, respectively, can uncover a hopeful and reliable insight for treatment and early diagnosis of cancer patients. In this review we will discuss our current understanding of regulatory role of miRNAs in Hippo signaling pathway.     

Delayed appearance of 3‐methylglutaconic aciduria in neonates with early onset metabolic cardiomyopathies: A potential pitfall for the diagnosis

Infantile onset cardiomyopathies are highly heterogeneous with several phenocopies compared with adult cardiomyopathies. Multidisciplinary management is essential in determining the underlying etiology in children's cardiomyopathy. Elevated urinary excretion of 3‐methylglutaconic acid (3‐MGA) is a useful tool in identifying the etiology in some metabolic cardiomyopathy. Here, we report the delayed appearance of 3‐MGA‐uria, between 6 and 18 months in three patients (out of 100 childhood onset cardiomyopathy) with neonatal onset cardiomyopathy, secondary to TMEM70 mutations and TAZ mutations (Barth syndrome), in whom extensive metabolic investigations, performed in the first weeks of life, did not display 3‐MGA‐uria. Serial retrospective evaluations showed full characteristic features of TMEM70 and TAZ mutations (Barth syndrome) in these three patients, including a clearly abnormal monolysocardiolipin/cardiolipin ratio in the two Barth syndrome patients. Serially repeated metabolic investigations finally discovered the 3‐MGA‐uria biomarker in all three patients between the age of 6 and 18 months. Our observation provides novel insights into the temporal appearance of 3‐MGA‐uria in TMEM70 and TAZ mutations (Barth syndrome) and focus the importance of multidisciplinary management and careful evaluation of family history and red flag signs for phenocopies in infantile onset cardiomyopathies.     

槐耳多糖调节YAP/TAZ信号通路对骨肉瘤细胞生物学行为的影响

目的 探讨槐耳多糖（PST）通过调节Yes相关蛋白(YAP)/转录共激活因子PDZ结合基序(TAZ)信号通路对骨肉瘤（OS）细胞生物学行为的影响。 方法 将OS细胞系G292细胞分为G292组（未做任何处理的G292细胞）、L-PST组(1 μg/mL PST)、M-PST组(2.5 μg/mL PST)、H-PST组(5 μg/mL PST)、GA-017组（10 μmol/L YAP/TAZ信号通路激活剂GA-017处理G292细胞）、H-PST+GA-017组（5 μg/mL PST+10 μmol/L GA-017）。CCK-8法检测细胞活性;流式细胞术检测G292细胞凋亡;划痕实验以及Transwell法检测G292细胞迁移和侵袭;Western blot检测YAP/TAZ通路蛋白、EMT相关蛋白、凋亡蛋白水平。结果 PST抑制OS细胞系MG63、Saos-2、U20S、G292细胞活性,且G292细胞的A450最小,因此,以G292细胞为研究对象。与G292组相比,M-PST组、H-PST组G292细胞A450值、迁移率、侵袭数量以及vimentin、N-cadherin、Bcl-2、p-YAP/YAP、TAZ蛋白水平均显著下降（P＜0.05）,细胞凋亡率、E-cadherin、Bax、cleaved-Caspase-3蛋白水平显著升高（P＜0.05）,GA-017组呈现相反的趋势（P＜0.05）,而L-PST组没有显著差异（P＞0.05）;GA-017削弱了H-PST对G292细胞恶性行为的抑制作用。结论 PST可能通过抑制YAP/TAZ信号通路来抑制OS细胞的增殖、迁移和侵袭