Wnt/β-catenin信号通路在乳腺癌中的研究进展

Wnt/β-catenin信号通路参与细胞增生分化的调节、基因表达调控和细胞迁移等重要生物过程.近年研究发现,Wnt/β-catenin信号通路的异常与乳腺癌等多种肿瘤的发生、发展密切相关.深入研究Wnt/β-catenin信号通路在乳腺癌中的作用,有助于进一步揭示乳腺癌的发生机制,为乳腺癌的防治提供新的思路及干预靶点.本文就Wnt/β-catenin通路的组成及调控机制、Wnt/β-catenin通路与乳腺癌发生、发展的关系及Wnt/β-catenin通路在乳腺癌诊治中的展望作一综述.     

Yes相关蛋白通过Wnt/β-catenin信号通路调控软骨细胞SOX9表达的实验研究

目的 研究Yes相关蛋白（YAP）通过Wnt/β-catenin信号通路调控软骨细胞SOX9表达的机制。 方法 用siRNA分别沉默YAP基因和LATS1基因来调控YAP的活性,通过Real-time PCR 检测软骨特异性基因和Wnt/β-catenin信号通路下游基因的表达;通过Western Blot检测GSK3β的磷酸化水平、活化β-catenin的蛋白水平以及SOX9的蛋白水平;并通过阿利新蓝染色检测软骨细胞外基质的分泌情况。用siRNA沉默YAP基因后,再用氯化锂干预细胞,通过Western Blot检测SOX9的表达和GSK3β的磷酸化水平。 结果 沉默YAP基因后,磷酸化GSK3β和活化β-catenin的蛋白水平减少,c-Myc和Nanog基因表达减少,SOX9、COL2和Aggrecan基因表达升高,并且软骨细胞分泌基质增多;沉默LATS1基因后,磷酸化GSK3β和活化β-catenin的蛋白水平增加,c-Myc和Nanog基因表达增加,SOX9、COL2和Aggrecan基因表达减少,并且软骨细胞分泌基质减少。此外,氯化锂可以阻断沉默YAP引起的SOX9表达上调。 结论 YAP通过Wnt/β-catenin信号通路调控软骨细胞SOX9的表达。     

Pygo2在经典Wnt信号通路中的作用及其研究进展

Wnt信号通路在正常组织发育以及肿瘤形成中起着重要作用.经典wnt信号通路通过促进关键蛋白β-catenin进入细胞核,与TCF/LEF结合,从而激活靶基因转录.Pygo是Wnt信号通路中新发现的成员,通过BCL9/Lgs与β-catenin结合,从而促进靶基因的转录.Pygo2的异常表达,与发育异常、肿瘤的形成有着紧密的联系.Pygo2在经典Wnt信号通路中的作用机制模式已经确定,但是与染色质重塑方面的机制有待进一步研究.最近研究发现Pygo2参与H3K56Ac,从而促进基因的表达.     

Wnt信号通路为靶点的肿瘤治疗新进展

Wnt信号传导通路与肿瘤的关系一直都是近年来肿瘤研究的热点,Wnt信号通路包含许多信号成员蛋白,其中任何一个成员蛋白的突变或异常均可激活Wnt信号通路引起细胞异常增殖而导致肿瘤的发生。为此,针对Wnt信号通路不同基因靶点的高特异性基因药物开发以及肿瘤的分子诊断也相继出现。目前,Wnt信号通路为靶点的肿瘤基因治疗包括细胞膜水平、胞内通路成员蛋白水平、β-catenin水平和核内TCF/LEFs-β-catenin复合体水平。     

SOX7、β-catenin和cyclin D1蛋白在浸润性乳腺癌组织中的表达及临床意义

目的 观察SOX7、β-catenin和cyclin D1蛋白在浸润性乳腺癌与乳腺良性增生病组织中的表达,探讨它们与浸润性乳腺癌临床病理学特征之间的关系,为浸润性乳腺癌的治疗、预后提供有价值的生物学标志.方法 应用免疫组化SP法分别检测50例浸润性乳腺癌与30例乳腺良性增生病中SOX7、β-cate-nin和cyclin D1蛋白的表达情况,分析SOX7、β-catenin和cyclin D1蛋白的表达与浸润性乳腺癌患者的发病年龄、肿瘤大小、腋窝淋巴结转移、组织学分级、病理学分期(pTNM)、雌激素受体(ER)、孕激素受体(PR)、人类表皮生长因子受体2(Her-2)和危险度分组之间的关系.结果 在50例浸润性乳腺癌组织中,SOX7和cyclin D1蛋白的阳性表达率分别为42％(21/50)和70％(35/50),β-catenin蛋白的异常表达率为70％(35/50).在浸润性乳腺癌中,SOX7蛋白的阳性率明显低于乳腺良性增生病的70％ (21/30) (P =0.021＜0.05),两组间差异有统计学意义;β-catenin蛋白的异常表达率和cyclin D1蛋白的阳性表达率均高于乳腺良性增生病的43.3％ (13/30) (P =0.033 ＜0.05)和20％ (6/30) (P =0.000＜ 0.001),两组间差异均有统计学意义.在50例浸润性乳腺癌中,SOX7和β-catenin蛋白同时阳性表达12例,同时阴性表达5例;SOX7和cyclinD1蛋白同时阳性表达11例,同时阴性表达5例;β-catenin和cyclinD1蛋白同时阳性表达28例,同时阴性表达8例.经Spearman相关分析,SOX7蛋白的阳性表达分别与p-catenin的异常表达和cyclin D1的阳性表达呈负相关关系(r=-0.282,P=0.046 ＜0.05;r =-0.327,P =0.020 ＜0.05),β-catcnin的异常表达与cyclin D1的阳性表达呈正相关关系(r=0.333,P=0.018 ＜0.05).在浸润性乳腺癌中,SOX7蛋白的表达在发病年龄、腋窝淋巴结转移、组织学分级、pTNM分期、ER、PR、Her-2和危险度分组间差异有统计学意义(P＜0.05),而在肿瘤直径分组间比较差异无统计学意义(P ＞0.05);β-catenin蛋白的异常表达和cyclin D1蛋白的阳性表达在肿瘤直径、腋窝淋巴结转移和pTNM分期分组间差异有统计学意义(P＜0.05),而在发病年龄、组织学分级、ER、PR、Her-2和危险度分组间比较差异无统计学意义(P＞0.05).结论 SOX7、β-cate-nin和cyclinD1蛋白在大多数浸润性乳腺癌组织中表达异常,且三者在浸润性乳腺癌发生、发展过程中可能通过同一通路发挥调节作用.SOX7、β-catenin和cyclin D1蛋白的表达与浸润性乳腺癌的临床病理学特征之间存在一定的相关性,检测三者的表达情况可成为临床上判断浸润性乳腺癌的恶性程度及预后的重要参考指标.     

微小RNA-30a-5p激活Wnt/β-连环蛋白信号通路对胃癌细胞增殖与侵袭的作用机制

目的探讨人微小RNA(has-miR)-30a-5p调控Wnt/β-连环蛋白(β-catenin)信号通路对胃癌细胞增殖及侵袭的影响及其作用机制。方法体外培养胃癌MKN-45细胞;在所研究胃癌细胞系中使用小干扰RNA(siRNA)转染建立miR-30a-5p的敲除和过表达模型, 胃癌MKN-45细胞分为3组:miR-30a-5p小干扰RNA(miR-30a-5p inhibitor)组, miR-30a-5p过表达RNA组和空白对照组(NC), 荧光定量聚合酶链反应(qPCR)和蛋白质印迹法(Western blot)检测Wnt/β-catenin信号通路相关标志物Cyclin D1(CCND1)基因的表达水平;双荧光素酶报告基因实验验证miR-30a-5p与Wnt信号通路下游关键基因CCND1的靶向调节关系;在培养的胃癌细胞MKN-45中加入Wnt/β-catenin信号通路抑制剂-银杏双黄酮, 分为miR-30a-5p inhibitor组、miR-30a-5p inhibitor+银杏双黄酮组、miR-30a-5p Inhibitor NC组及miR-30a-5p Inhibit...     

内皮抑素对人脑胶质瘤GL15细胞株β-catenin和Cyclin D1表达的影响

目的 探讨内皮抑素对人脑胶质肉瘤细胞株GL15中β-catenin和Cyclin D1表达的影响.方法 通过质粒转染的方法 向GL15细胞中转染pcDNA 3.1 ES质粒,通过SABC免疫组织化学方法 检测转染组与非转染组细胞中β-catenin和Cyclin D1表达.结果 空白对照组细胞爬片中β-catenin和Cyclin D1的平均光密度值分别为(0.3758±0.0371)和(0.4092±0.0417),而内皮抑素质粒转染组细胞爬片中β-catenin和Cyclin D1的平均光密度值分别为(0.2462±0.0275)和(0.2046±0.0357);空白对照组中β-catenin和Cyclin D1的平均光密度值均高于内皮抑素转染组,统计学分析表明在不同组别之间,β-catenin的平均光密度值有显著性差异,其中Cyclin D1的平均光密度值有极显著性差异.结论 内皮抑素在GL15细胞株中可以抑制β-catenin蛋白的过度表达和异位表达,并通过直接和间接的途径,抑制Cyclin D1蛋白的过度表达,从而发挥抑制肿瘤发展的作用.     

Wnt/β-catenin信号通路在脊柱小关节骨性关节炎中的作用

脊柱小关节骨性关节炎是由多种因素导致脊柱小关节的关节软骨发生损伤及退变的骨性关节炎。近来研究显示,Wnt/β-catenin信号通路在脊柱小关节骨性关节炎的发生发展过程中发挥着重要的作用,合适的胞内Wnt/β-catenin表达水平是影响临床表型的重要因素。针对Wnt/β-catenin信号通路的抑制剂、条件性激活/敲除的研究,有助于研究人员进一步了解Wnt/β-catenin信号通路在脊柱小关节骨性关节炎发病机制中的作用。本文将对Wnt/β-catenin信号通路及其在骨性关节炎、特别是脊柱小关节骨性关节炎中的最新研究结果和进展进行综述,并对未来的研究提出展望。     

Sox基因的异常表达与乳腺癌研究的进展

Sox基因家族是一类SRY相关基因构成的基因家族,编码一系列Sox家族的转录因子.Sox基因在个体发育过程中参与了性别决定和分化、神经发育、软骨形成等多种发育过程.近年研究者发现,Sox基因的异常表达与乳腺癌的发生、发展有一定关系,如Sox2、Sox4的过表达与乳腺癌的发生相关;Sox7和Sox17在乳腺癌中可作为抑癌基因,其表达下调可激活Wnt/β-catenin信号通路,与乳腺癌的发生发展有一定关系.     

Wnt/β-catenin信号通路与肾性骨病

大量研究显示Wnt/β-catenin信号通路在肾性骨病发生发展中具有重要作用。本文从生理、病理两个层面综述了Wnt/β-catenin信号通路在肾骨调控中的作用。在生理状态下,Wnt/β-catenin信号通路不仅具有调节肾形成祖细胞自我更新与分化,进而形成足量的肾单位的作用,而且可以促进多能间充质干细胞分化成成骨细胞系,抑制其向软骨以及脂肪细胞系分化的同时抑制成骨细胞凋亡,延长其生命,促进骨形成,还可以通过调节OPG的表达抑制破骨细胞分化和骨吸收。当肾脏受损后,在SOST、DKK1、Vitamin D/VDR、FGF23/α-Klotho、PTH/PTH1R、TGF-β/BMPs等诸多因素直接或间接影响下,一方面骨细胞中Wnt/β-catenin信号表达异常,影响正常的骨形成与骨吸收,引起骨稳态失衡进而发生骨病,另一方面肾脏中Wnt/β-catenin信号的异常表达或加速或修复自身损伤,并进一步影响骨稳态。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.