Anoikis disruption of focal adhesion-Akt signaling impairs renal cell carcinoma

Background

Quinazoline-based α1-adrenoceptor antagonists suppress tumor growth by inducing apoptosis via an α1-adrenoceptor-independent action. Anoikis is a unique mode of apoptosis consequential to insufficient cell-matrix interactions.

Objective

This study investigated the apoptotic effect of novel quinazoline-based compounds on human renal cancer cells.

Design, setting, and participants

Two cell lines were used: renal cell carcinoma (RCC) 786-0, harboring a von Hippel-Lindau (VHL) tumor-suppressor gene mutation with a highly angiogenic phenotype, and Caki cells (no VHL mutation).

Measurements

The lead compound DZ-50 (10 μM) led to significant inhibition of tumor-cell adhesion, migration, and invasion at a lower dose than doxazosin (25 μM) in both RCC lines.

Results and limitations

Doxazosin induced death-receptor-mediated apoptosis, while DZ-50 led to anoikis via targeting of the focal adhesion complex and AKT signaling that subsequently increased RCC susceptibility to caspase-8-mediated apoptosis. Both quinazoline compounds, doxazosin and DZ-50, significantly reduced RCC metastatic potential in vivo.

Conclusions

Quinazoline-based drugs trigger anoikis in RCC by targeting the focal adhesion survival signaling. This potent antitumor action against human RCC suggests a novel quinazoline-based therapy targeting renal cancer.     

Genetic analysis and effect of triiodothyronine and prednisone trial on bone turnover in a patient with craniotubular hyperostosis

Craniotubular hyperostosis are a group of high bone mass disorders related to mutations in the LRP5 and SOST genes, although other causative genes remain to be identified. Little is known about the bone turnover and the response to T3 or glucocorticoids in these patients. We describe a patient with craniotubular hyperostosis, including mutation analyses of the LRP5, SOST, DKK1 and KRM1 genes. We also studied bone turnover and bone mineral density (BMD), before and after a trial with T3 (75 microg/d for 28 weeks) and T3 and prednisone (T3 100 microg/d for 2 weeks, followed by 10 weeks on prednisone 10 mg/d, and a final 2 weeks period off of medicactions, completing 3 cycles in 42 weeks. Mutation analysis of the complete coding region and flanking highly conserved sequences of SOST, evaluation of the presence of the 52-kb deletion associated with Van Buchem disease in Dutch patients and mutation analysis of exons 2-4 of LRP5, and the coding regions of DKK1 and KRM1 did not reveal any disease-causing mutations. A baseline 5 to 7 fold increase in osteocalcin and in deoxypiridinoline was detected. After 4 weeks on 75 microg/d of T3, osteocalcin decreased 36%, but at week 28, it returned to basal. Deoxypiridinoline did not change. After the first cycle on T3 and prednisone, osteocalcin decreased 72%, and at the end of the third cycle it remained 44% below basal value. Deoxypiridinoline was stable and high during the three cycles; no changes in BMD were observed. As we failed to identify any disease-causing mutations in our patient with craniotubular hyperostosis, we suggest that another gene must be involved in the pathogenesis of his condition. This study provides additional data about the high bone turnover described in craniotubular hyperostosis, and also suggests an abnormal response to T3 excess in this condition.     

17β-雌二醇对子宫内膜异位症患者在位子宫内膜间质细胞β-catenin mRNA和蛋白表达的影响

目的研究17β-雌二醇(17β-E2)对子宫内膜异位症(内异症)患者在位子宫内膜间质细胞β-catenin mRNA和蛋白表达的影响,探讨Wnt/β-catenin信号通路在介导雌激素促进内异症发生发展的作用。方法体外分离培养内异症患者在位子宫内膜间质细胞。用不同浓度17β-E2处理子宫内膜间质细胞48 h;此后选用10-10mol/L 17β-E2处理子宫内膜间质细胞12、24和48 h,逆转录聚合酶链反应(RT-PCR)和免疫印迹法(Western blotting)检测17β-E2处理前后子宫内膜间质细胞β-catenin mRNA和蛋白的表达水平。同法分析雌激素受体拮抗剂ICI182,780(10-6mol/L)对17β-E2促进β-catenin mRNA和蛋白表达的影响。免疫组织化学染色观察17β-E2作用后β-catenin在子宫内膜间质细胞中的定位。结果17β-E2能明显促进内异症患者在位子宫内膜间质细胞β-catenin mRNA和蛋白的表达,并呈剂量和时间依赖性,于10-10mol/L作用48 h最明显。雌激素受体拮抗剂ICI182,780能明显抑制17β-E2对子宫内膜间质细胞β-catenin mRNA和蛋白的表达。免疫组织化学染色发现17β-E2能促进β-catenin在子宫内膜间质细胞核内的表达。结论雌激素可能通过激活Wnt/β-catenin信号通路促进内异症在位子宫内膜的异位种植。     

Secreted Wnt Antagonists During Eradication of Cytomegalovirus Infection in Solid Organ Transplant Recipients

We evaluated secreted wingless (Wnt) modulators during cytomegalovirus (CMV) infection in solid organ transplant recipients (SOTr). The major findings were: (i) Plasma levels of Dickkopf‐1 (DKK‐1) were significantly lower in patients with CMV DNAemia above lower level of quantification at baseline. (ii) Receiver operating characteristic analysis indicated that low DKK‐1 and increased secreted frizzled related protein‐3 levels were predictors of poor virological outcomes during follow‐up. Our findings demonstrate an imbalanced pattern of circulating secreted Wnt modulators in SOTr with poor virological outcomes following treatment for CMV disease, and may suggest a role for dysregulated Wnt signaling on viral pathogenesis during CMV infection.     

原发性高血压患者WNK-SPAK激酶通路的表达及饮食干预的影响

目的：通过研究原发性高血压患者WNK1激酶（ with no lysine kinase 1）-STE20相关脯氨酸/丙氨酸丰富激酶（ Ste20-related proline/alanine-rich kinase,SPAK）信号通路的表达水平,以及低钠高钾饮食干预后表达水平的变化,探讨其在原发性高血压中的致病作用。方法：75名未经治疗的高血压患者经低钠高钾饮食干预1个月,通过Realtime PCR对干预前后外周血中的WNK1和SPAK的mRNA表达水平进行检测,并观察受试者血压、血尿生化指标变化。结果：高血压患者组外周血中WNK1和SPAK mRNA水平的表达较健康志愿者组明显升高,低钠高钾饮食干预后信号通路的表达则较基线期明显下降。统计学分析表明WNK1激酶的表达水平与血压之间存在相关性。结论：WNK1-SPAK激酶通路的表达异常可能参与原发性高血压的发病,饮食结构的变化可通过改变WNK1-SPAK-NCC信号通路的表达而调节血压。     

Effects of WNK3 kinase on regulation of large-conductance calcium-activated potassium channels and its mechanisms

Objective To investigate the effects of WNK3 kinase on the regulation of large-conductance calcium-activated potassium channels (Maxi K channels) on African green monkey kidney fibroblast-like cells (Cos-7 cells) and its mechanisms. Methods (1) Cos-7 cells were transfected with 0, 0.6, 1.2, 1.8 μg WNK3 plasmid+0.5 μg Maxi K plasmid. The total protein expression of Maxi K channel and the phosphorylation of mitogen-activated protein kinase (MAPK) extracellular regulated kinase-1 and-2 (ERK1/2) were detected by Western blotting. (2) Cos-7 cells were divided into the control group (2.5 μg Maxi K plasmid) and the experimental group (2.5 μg WNK3 plasmid+2.5 μg Maxi K plasmid). Cell surface biotinylation was used to investigate the cell surface protein expression of Maxi K channel in Cos-7 cells. Immunoprecipitation and Western blotting were used to detect the ubiquitination of Maxi K channel protein. (3) WNK3 kinase was knocked down by WNK3 siRNA. The lysosomal degradation pathway was blocked by the proton pump inhibitor (Baf-A1). Cos-7 cells were divided into Maxi K+negative control siRNA group, Maxi K+WNK3 siRNA group and Maxi K+WNK3 siRNA+Baf-A1 group. The protein expression of Maxi K channel protein was detected by Western blotting. Results (1) Compared with those in 0 μg WNK3 plasmid groups, in 0.6, 1.2, 1.8 μg WNK3 plasmid groups the total protein expression of the Maxi K channel increased and the phosphorylation level of MAPK ERK1/2 reduced on a dose-dependent manner (all P＜0.01). (2) Compared with those in the control group, the total protein expression and cell surface membrane protein expression of the Maxi K channel increased in the experimental group (P＜0.01), while the ubiquitination of the Maxi K channel protein reduced (P＜0.01). (3) Compared with the Maxi K+negative control siRNA group, the expression of Maxi K protein reduced in the Maxi K+WNK3 siRNA group (P＜0.01), but did not change in the Maxi K+WNK3 siRNA+Baf-A1 group (P＞0.05). The expression of Maxi K protein in Maxi K+WNK3 siRNA+Baf-A1 group was higher than that in Maxi K+WNK3 siRNA group (P＜0.01). Conclusions WNK3 kinase inhibits the lysosomal degradation pathway of Maxi K channel protein by reducing the ubiquitination of Maxi K channel, and promotes the expression of Maxi K channel protein in cells and on cell membrane. These effects may be achieved by suppressing MAPK ERK1/2 signal transduction pathway.     

The role of PI3K/Akt signaling pathway in non‐physiological shear stress‐induced platelet activation

The PI3K/Akt signaling pathway has been implicated in playing an important role in platelet activation during hemostasis and thrombosis involving platelet‐matrix interaction and platelet aggregation. Its role in non‐physiological shear stress (NPSS)‐induced platelet activation relevant to high‐shear blood contacting medical devices (BCMDs) is unclear. In the context of blood cells flowing in BCMDs, platelets are subjected to NPSS (>100 Pa) with very short exposure time (<1 s). In this study, we investigated whether NPSS with short exposure time induces platelet activation through the PI3K/Akt signaling pathway. Healthy donor blood treated with or without PI3K inhibitor was subjected to NPSS (150 Pa) with short exposure time (0.5 s). Platelet activation indicated by the surface P‐selectin expression and activated glycoprotein (GP) IIb/IIIa was quantified using flow cytometry. The phosphorylation of Akt, activation of the PI3K signaling, was characterized by western blotting. Changes in adhesion behavior of NPSS‐sheared platelets on fibrinogen, collagen, and von Willebrand factor (vWF) were quantified with fluorescent microscopy by perfusing the NPSS‐sheared and PI3K inhibitor‐treated blood through fibrinogen, collagen, and vWF‐coated microcapillary tubes. The results showed that the PI3K/Akt signaling was involved with both NPSS‐induced platelet activation and platelet‐matrix interaction. NPSS‐sheared platelets exhibited exacerbated platelet adhesion on fibrinogen, but had diminished platelet adhesion on collagen and vWF. The inhibition of PI3K signaling reduced P‐selectin expression and GPIIb/IIIa activation with suppressed Akt phosphorylation and abolished NPSS‐enhanced platelet adhesion on fibrinogen in NPSS‐sheared blood. The inhibition of PI3K signaling can attenuate the adhesion of unsheared platelets (baseline) on collagen and vWF, while had no impact on adhesion of NPSS‐sheared platelets on collagen and vWF. This study confirmed the important role of PI3K/Akt signaling pathway in NPSS‐induced platelet activation. The finding of this study suggests that blocking PI3K/Akt signaling pathway could be a potential method to treat thrombosis in patients implanted with BCMDs.     

γ-氨基丁酸B型受体对结肠癌HCT116细胞周期的影响

目的利用人结肠癌细胞株HCT116细胞为研究模型,探究γ-氨基丁酸B型受体（GABABR）/糖原合成激酶3β（GSK-3β）/核转录因子（NF-κB）信号通路对结肠肿瘤细胞HCT116周期的影响,明确GABABR调控结肠癌细胞增殖的机制。 方法使用人结肠癌细胞株HCT116细胞为模型,构建针对GABABR的shRNA,流式细胞仪检测不同刺激条件下HCT116细胞周期分布,四甲基偶氮唑盐微量酶反应比色法（MTT）、5-溴脱氧尿嘧啶核苷（Brdu）法检测细胞的增殖能力变化。 结果GABABR可调控HCT116细胞的增殖。GABABR激动剂巴氯芬将HCT116细胞滞留在G1期,GSK-3β激动剂wort能逆转巴氯芬对结肠癌的该作用;GSK-3β抑制剂SB216763处理后,HCT116细胞增殖得到抑制,而NF-κB激动剂PMA可以阻断此作用;NF-κB激动剂PDTC能够回救敲低GABABR所引起的HCT116细胞增殖抑制,Akt抑制剂MK-2206 2HCl能逆转巴氯芬、SB216763对HCT116细胞增殖的抑制作用。 结论GABABR/GSK-3β/NF-κB信号通路可以调控结肠癌细胞增殖,通过抑制GSK-3β的活性,抑制NF-κB信号通路的激活,将HCT116细胞滞留在G1期。GABABR/GSK-3β/NF-κB信号通路可以作为临床预防和治疗结肠癌的潜在药物靶点之一。     

药源性胃肠道出血及其病理机制的研究进展

药源性胃肠道出血是由于药物作用于胃肠道,引发胃肠黏膜糜烂、出血。引发胃肠道出血的常见药物包括非甾体抗炎药、抗血栓药、化疗药、抗菌药等,药物通过破坏胃肠道黏膜屏障、抑制血管生成、破坏机体凝血机制等途径诱发胃肠道出血,临床尚缺乏有效的防治办法。本文从药物临床研究现状和病理机制出发,综述了近5年国内外对药物引发胃肠道出血的研究进展,以期阐释药物引发胃肠道出血的作用特点,为发现防治药源性胃肠道出血的可能策略提供参考和线索。     

伊马替尼抑制脂多糖诱导的巨噬细胞炎症表型

【目的】探讨伊马替尼（Ima）在体外对脂多糖（LPS）诱导的RAW264.7巨噬细胞炎症表型的影响。【方法】RAW264.7细胞在LPS（0.1μg/mL）或/和Ima（1μmol/L,5μmol/L）处理后,通过Q-PCR方法检测细胞因子IL-1β、IL-10、CCL2、iNOS、TNF-α和Arg1的mRNA表达变化;采用Western Blot检测iNOS蛋白表达变化以及NF-κB和MAPK信号通路活化情况;利用ELISA法检测细胞上清IL-1β、CCL2、IL-10和TNFα的蛋白表达情况。【结果】与对照组相比较,LPS刺激8h后,RAW264.7细胞内的炎症指标IL-1β、CCL2、iNOS和TNF-α的mRNA水平显著升高（P<0.001）以及抗炎指标IL-10的mRNA水平也明显升高（P<0.001）;LPS刺激24h后,细胞上清中IL-1β、IL-10、CCL2和TNF-α的蛋白水平显著上升（P<0.001）,细胞内iNOS蛋白表达以及p65,p38,ERK和AKT的磷酸化水平显著增加。和LPS组相比,Ima提前处理后,IL-1β、CCL2、iNOS和TNF-α的mRNA及蛋白水平显著下降（P<0.01,P<0.001）而IL-10的mRNA及蛋白水平显著升高（P<0.001）,这种抑制作用具有剂量依赖性。Ima的预处理抑制了LPS诱导的p65,p38,ERK和AKT磷酸化。单独用Ima处理RAW264.7细胞后,细胞的功能状态未见明显的改变。【结论】伊马替尼可抑制LPS诱导的巨噬细胞炎症表型,这种作用与抑制NF-κB和MAPK信号通路的过度激活有关。