Hepatic gene downregulation following acute and subchronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Chronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been shown to lead to the development of hepatotoxicity and carcinogenicity in the liver of female rats. In this study, we investigated hepatic gene downregulation in response to acute and subchronic TCDD exposure. We identified 61 probes which exhibited a downregulation of twofold or greater following subchronic (13 weeks) exposure to TCDD. Comparative analysis of the hepatic expression of these 61 probes was conducted with rats subchronically exposed to PeCDF, PCB126, PCB153, and a mixture of PCB126 and PCB153. PCB153 produced little or no alteration in these probes, while the binary mixture mimicked most closely the downregulation observed with TCDD. To discern if the repression of genes within this probe set occur as a primary response to TCDD exposure, we analyzed the early responsiveness of 11 genes at 6, 24, and 72 h following a single exposure to TCDD. We observed early repression of the 11 genes within this early time course, indicating that the repression of this subset of genes occurs as a primary response to TCDD exposure and not as a secondary response to 13 weeks of subchronic treatment. In addition, the gender, species, and AhR dependence of these responses were also investigated. Gender- and species-dependent repression was observed within this subset of genes. Furthermore, utilizing AhR knockout mice, we were able to determine the AhR-dependent downregulation of seven of 11 genes. Together these results assist efforts to understand the multitude of effects imposed by TCDD and AhR ligands on gene expression.     

Urodilatin: a new peptide with beneficial effects in the postoperative therapy of cardiac transplant recipients

Summary Renal failure after heart transplantation (HTx) still remains a serious problem, especially when cyclosporin A is used for immunosuppression in the early postoperative therapy. To preserve good renal function without reducing immunosuppressive cyclosporin A treatment, we administered urodilatin (CDD/ANP-95-126) in a long-term, low-dose infusion in addition to the usual medication after heart transplantation. From November 1990 to June 1991, 51 patients (46 male and 5 female; mean age 48 years) were treated with a 620 ng/kg bw·min infusion for 96 h after HTx. The renal function and hemodynamic parameters of these urodilatin-treated patients were compared in this sequential study with 40 patients (33 male and 7 female; mean age 49 years) who had undergone HTx previously from May to November, 1990, as controls. In this phase IIa study, both groups did not differ significantly with respect to age, sex, indication for HTx, and preoperative renal function. In comparison with controls patients treated with urodilatin had a significantly better renal function: a reduction in the peak plasma creatinine (PC values day 4 : 1.5 ± 0.11 vs. 2.19 ± 0.19 mg/dl; P = 0.002), a lower peak serum urea (SU values day 4 : 109 ± 8 vs. 154.7 ± 8.94 mg/dl ; P = 0.0036), and a lower incidence of hemodialysis (6% vs. 10%) were observed. Adequate diuresis was maintained in spite of the reduction of furosemide by more than 60% (P = 0.005) on each day of urodilatin infusion in comparison with controls. The mean central venous pressure was significantly lower by about 50% (P = 0.02) during the administration of urodilatin in spite of reduced vasodilator medication with nitroglycerin. From this phase IIa study, we may conclude that urodilatin could be an important drug in intensive care treatment. For patients undergoing HTx, this peptide seems to be indicated for the improvement of renal function and cardiovascular status, especially in postoperative therapy using high-dose cyclosporin A treatment.Abbreviations ACE angiotensin converting enzyme - ANP atrial natriuretic polypeptide - ATG antithymocyte globulin - bpm beats per minute - bw body weight - CDD cardiodilatin - CDD/ANP-99-126 circulating form of vasorelaxant cardiac peptide - CHD coronary heart disease - CyA cyclosporin A - DCM dilated cardiomyopathy - GLM general linear model - hANP human atrial natriuretic polypeptide - HTx heart transplantation - NTG nitroglycerine - PC plasma creatinine - SU serum urea - SAS statistical analysing system     

Atrial natriuretic factor and autonomic nervous system function in man

Summary To delineate a possible interaction of atrial natriuretic peptide ANF-(99–126) with autonomic nervous system function in humans, a spectrum of indices were assessed in 10 healthy young men during a 90 min iv administration of a) synthetic ANF-(99–126) 50 g bolus followed by 0.025 g·kg^–1·min^–1, b) the potent vasodilator sodium nitroprusside (SNP) 0.35 g·kg^–1·min^–1, or c) vehicle 0.9% NaCl 40 ml and 20% albumin 5 ml, in random sequence.Plasma immunoreactive ANF (irANF) rose from 32 to 1700 pg·ml^–1 during the ANF-(99–126) infusion and was stable during SNP or vehicle. Infusion of ANF-(99–126) and SNP, but not vehicle, decreased diastolic blood pressure (BP) on average by –9 and –7.5%, respectively; systolic BP was largely unchanged. Heart rate (HR, +15 and 12%) or plasma norepinephrine (NE) rose similarly during ANF-(99–126) and SNP infusions, and the systolic BP response to orthostasis was similar (–18 mm Hg). The following autonomic indices did not differ significantly after the 3 infusions: responses of HR and NE to orthrostasis; reflex bradycardic response to phenylephrine (PE)-induced rise in systolic BP (+20 mm Hg); responses of BP to hyperventilation, PE, or 3 min of sustained handgrip; and beat-to-beat variation (R-R interval) during deep breathing. The immediate orthostatic HR response (30/15 R-R interval ratio) fell similarly during infusion of ANF-(99–126) or nitroprusside.The findings indicate that in healthy men the function of the autonomic nervous system is not notably impaired by high circulating ANF levels. ANF-(99–126) infused in moderate dosage seems to lower BP largely by non-autonomic mechanisms.The study was supported in part by the Swiss National Science Foundation     

Droplet digital PCR and qRT-PCR to detect circulating miR-21 in laryngeal squamous cell carcinoma and pre-malignant laryngeal lesions

Conclusions: The present study indicates that miR-21 is involved in progression from normal to pre-malignant laryngeal lesions (PLLs) and from PLLs to laryngeal squamous cell carcinoma (LSCC). Furthermore, normalized PCR results for miR-21 might be used to discriminate between normal and ordinary hyperplasia before the emergence of dysplasias and pre-malignant lesions with malignant potential. Objective: To investigate a sensitive marker that contributes to progression from normal tissue to PLLs and from PLLs to LSCC. Methods: In 116 PLLs and LSCC patients and 19 without dysplasia matched sets of tissue and plasma samples from Beijing Tongren Hospital, miR-21 was analysed by droplet digital PCR and quantitative real-time polymerase chain reaction based on paraffin-embedded tumour tissue and plasma. Results: Compared with controls, miR-21 levels in tissue and plasma were significantly higher for both PLL and LSCC groups (for both groups vs controls: p p?相似文献   

高危型HPV阳性宫颈癌患者miRNA-34a-5p的表达及临床意义

目的　探讨高危型人乳头状瘤病毒（high risk-human papilloma virus, HR-HPV）阳性宫颈癌患者组织及血清中微小RNA（microRNA, miRNA）-34a-5p的表达及其对宫颈癌的诊断价值。方法　将100例HR-HPV阳性宫颈癌患者（宫颈癌组）、70例宫颈上皮内瘤变（cervical intraepithelial neoplasia, CIN）患者（CIN组）、70例HR-HPV阳性子宫良性病变或者HPV单纯阳性的健康体检者（对照组）作为研究对象。采集上述研究对象的血清标本及70例行手术治疗的宫颈癌组患者癌组织及癌旁组织。使用实时荧光定量PCR技术测定组织及血清中miRNA-34a-5p水平，并分析miRNA-34a-5p与宫颈癌临床、病理指标的关联及血清miRNA-34a-5p对宫颈癌的诊断价值。结果　①对照组血清中miRNA-34a-5p的相对表达量高于CIN组和宫颈癌组：（0.933±0.097）vs.（0.554±0.099）vs.（0.369±0.099），差异有统计学意义（F=741.401，P=0.000）；宫颈癌组患者术前血清中miRNA-34a-5p相对表达量低于术后1周，差异有统计学意义（t=8.305，P=0.000）。有无淋巴结转移和有无远处转移的宫颈癌患者血清中miRNA-34a-5p相对表达量的差异有统计学意义（P均＜0.05）。②宫颈癌组患者癌旁组织中miRNA-34a-5p的相对表达量高于癌组织，差异具有统计学意义（t=40.313，P=0.000）。③宫颈癌组患者癌组织中的miRNA-34a-5p表达水平与血清中的表达水平呈正相关（r=0.908，P=0.000）。④以0.508为miRNA-34a-5p相对表达量的最佳临界值诊断宫颈癌，其灵敏度为83.6%，特异度为79.4%，AUC为0.860，95%置信区间为0.803～0.917。结论　HR-HPV阳性宫颈癌患者癌组织和血清中miRNA-34a-5p表达下调，对宫颈癌诊断及预后监测具有一定的参考价值。     

miRNA-34c在鼻咽癌组织中的表达及意义

目的检测miRNA-34c在鼻咽癌组织中的表达情况,并探讨其在鼻咽癌发生、发展中的意义。方法以实时定量聚合酶链式反应(quantitative real-time polymerase chain reaction,qRT-PCR)方法检测28例鼻咽癌石蜡包埋组织中相对于28例鼻咽部慢性炎症石蜡包埋组织中miRNA-34c的差异表达情况,并结合临床资料及随访结果分析miRNA-34c与鼻咽癌病例临床因素的相关性。结果鼻咽癌组织中miRNA-34c的相对表达量明显低于鼻咽部慢性炎症组织,差异有统计学意义(P<0.05)。且随着临床分期的增高、淋巴结转移,miRNA-34c的表达呈下降趋势。结论 miRNA-34c可能参与鼻咽癌的发生与发展,调控miRNA-34c的表达量有望为鼻咽癌的治疗提供一种新的思路或方法。     

Enhancer of zeste homologue 2 plays an important role in neuroblastoma cell survival independent of its histone methyltransferase activity

Neuroblastoma is predominantly characterised by chromosomal rearrangements. Next to V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma Derived Homolog (MYCN) amplification, chromosome 7 and 17q gains are frequently observed. We identified a neuroblastoma patient with a regional 7q36 gain, encompassing the enhancer of zeste homologue 2 (EZH2) gene. EZH2 is the histone methyltransferase of lysine 27 of histone H3 (H3K27me3) that forms the catalytic subunit of the polycomb repressive complex 2. H3K27me3 is commonly associated with the silencing of genes involved in cellular processes such as cell cycle regulation, cellular differentiation and cancer. High EZH2 expression correlated with poor prognosis and overall survival independent of MYCN amplification status. Unexpectedly, treatment of 3 EZH2-high expressing neuroblastoma cell lines (IMR32, CHP134 and NMB), with EZH2-specific inhibitors (GSK126 and EPZ6438) resulted in only a slight G1 arrest, despite maximum histone methyltransferase activity inhibition. Furthermore, colony formation in cell lines treated with the inhibitors was reduced only at concentrations much higher than necessary for complete inhibition of EZH2 histone methyltransferase activity. Knockdown of the complete protein with three independent shRNAs resulted in a strong apoptotic response and decreased cyclin D1 levels. This apoptotic response could be rescued by overexpressing EZH2ΔSET, a truncated form of wild-type EZH2 lacking the SET transactivation domain necessary for histone methyltransferase activity. Our findings suggest that high EZH2 expression, at least in neuroblastoma, has a survival function independent of its methyltransferase activity. This important finding highlights the need for studies on EZH2 beyond its methyltransferase function and the requirement for compounds that will target EZH2 as a complete protein.