人α干扰素诱导骨肉瘤细胞Anoikis凋亡

目的：恶性肿瘤细胞逃避Anoikis凋亡的特性是其原位侵袭和远处转移的一个重要原因。本文旨在研究应用人干扰素（IFN）α2a诱导骨肉瘤细胞出现Anoikis凋亡，并深入探讨其产生机理及信号传导途径。方法：采用抑制接触培养法建立细胞Anoikis凋亡诱导模型。观察IFN－α2a诱导骨肉瘤细胞MG－63产生的Anoikis凋亡。TUNEL法形态学检测MG－细胞凋亡，流式细胞仪定量检测细胞凋亡程度和细胞表面整联蛋白受体表达。特异性底物切开法检测半胱氨酸天门冬氨酸特异性蛋白酶（cysteine aspartate-specific proteases,caspase)信号途径。结果：人IFN－α2a可明显诱导骨肉瘤细胞MG－63产生Anoikis现象，并诱导了MG－63细胞caspase-8和caspase-3的活性，但IFN对整联蛋白亚单位α4，α5及αv无明显影响，上述整联蛋白封闭抗体对IFNα－2a诱导的MG－63细胞Anoikis凋亡无明显影响。结论：人干扰素α2a可以在体外通过调节细胞caspase信号途径，诱导骨肉瘤细胞MG－63产生Anoikis现象，从而抑制骨肉瘤的转移。     

抑癌基因PTEN依赖其磷酸活性诱导人膀胱癌细胞BIU-87失巢凋亡机制

Objective： To investigate the effects and mechanisms of tumor suppressor gene PTEN on the induction of anoikis of human bladder transitional carcinoma cells BIU-87. Methods： BIU-87 cells were transfected with GFP plasmids containing wild-type PTEN or phosphatase inactivating mutant PTEN （C124A-PTEN） in vitro. The PTEN expression and the phosphorylation levels of focal adhesion kinase （FAK） and protein kinase B （PKB/Akt） were detected by Western blotting. Flow cytometry assay and laser scanning confocal microscopy were used to analyze apoptosis in adherent and non-adherent cells. Results： Compared with the control group; PTEN expression in the cells transfected with wild-type PTEN increased to 210%-260%, while the phosphorylation level of FAK and Akt decreased 59% （ P 〈 0.01） and 89% （ P 〈 0.01）, respectively. And the anoikis percentage increased from 8,32 ± 0.57% to 37.62 ± 2.12%, In the cells transfected with C124A-PTEN, neither the phosphorylation of FAK and Akt nor the anoikis percentage had obviously changed, although the PTEN expression enhanced remarkably in comparison with the control. Conclusion： Through its phosphatase activity, tumor suppressor gene PTEN can suppress the phosphorylation of FAK and Akt, and induce anoikis in human bladder transitional carcinoma cells BIU-87.     

中医药调控肺癌失巢凋亡研究进展

失巢凋亡是机体细胞与细胞外基质或其他细胞失去接触而诱导的一种特殊的程序化细胞死亡形式,在肺癌研究中具有重要价值。在本篇综述中,我们首先从中医理论探讨了失巢凋亡的含义,然后介绍了失巢凋亡涉及的相关机制及信号通路,最后总结目前中医药调控肺癌细胞失巢凋亡的相关研究。     

姜黄素抑制结肠癌SW620细胞侵袭的体外实验研究

目的：观察姜黄素对结肠癌SW620细胞侵袭的影响,并探讨其作用机制。方法：应用姜黄素处理人结肠癌细胞系SW620后,采用软琼脂集落培养试验检测锚着不依赖性增殖,采用Boyden小室模型试验检测癌细胞的侵袭性,采用琼脂糖凝胶电泳和TUNEI,检测癌细胞失巢凋亡。结果：姜黄素可有效抑制结肠腺癌细胞集落生长和穿膜侵袭能力,且与浓度相关。琼脂糖凝胶电泳和TUNEL结果显示,姜黄素可诱导结肠癌细胞失巢凋亡,且与浓度和时间相关。结论：姜黄素呵抑制人结肠癌细胞侵袭,诱导失巢凋亡是其机制之一。     

Detachment‐Based Equilibrium of Anoikic Cell Death and Autophagic Cell Survival Through Adaptor Protein p66Shc

Anoikis (detachment‐induced cell death) confers a tumor‐suppressive function in metastatic cancer cells. Autophagy, a conserved self‐degradative process, enhances the anoikis resistance of detached cancer cells by maintaining cellular homeostasis. However, the mechanism of regulating cell fate‐decision by balancing anoikis and autophagy has been poorly understood. Our previous studies have shown that the adaptor protein p66^Shc mediates anoikis through RhoA activation and inhibits tumor metastasis in vivo. We also found that p66^Shc depletion mitigates nutrient‐deprivation‐induced autophagy. These findings suggest p66^Shc may coordinately regulate these two processes. To verify this hypothesis, we investigated the effect of p66^Shc on the cell death of detached lung cancer cells, and measured autophagy markers and autophagic flux. Results showed that p66^Shc depletion significantly inhibited anoikis, and reduced the formation of LC3B‐II and the degradation of Sequestosome 1 (SQSTM1, p62) in detachment‐induced cells. Using monodansylcadaverine (MDC)‐LysoTracker double staining and monomeric Cherry (mCherry)‐GFP‐LC3 assay, we found that the autophagic flux was also mitigated by p66^Shc depletion. In addition, p66^Shc knockdown increased the formation of full‐length X‐linked inhibitor of apoptosis (XIAP)‐associated factor 1 (XAF1), which enhances anoikis sensitivity. In conclusion, p66^Shc plays an essential role in detachment‐based equilibrium of anoikic cell death and autophagic cell survival. Anat Rec, 299:325–333, 2016. © 2015 Wiley Periodicals, Inc.     

MTA1基因调控人前列腺癌PC-3细胞失巢凋亡的研究

目的:探讨MTA1基因小干扰RNA(siRNA)对前列腺癌细胞PC-3增殖和失巢凋亡的影响。方法:应用MTA1 siRNA转染处理人前列腺癌细胞系PC-3后,采用实时定量PCR和W estern印迹检测MTA1基因mRNA和蛋白水平,采用软琼脂集落培养试验检测锚着不依赖性增殖,采用琼脂糖凝胶电泳和流式细胞术检测癌细胞失巢凋亡。结果:与对照组比较,MTA1基因siRNA转染组MTA1 mRNA和蛋白水平明显下降,且呈浓度依赖性(r=0.935,P=0.0001)。MTA1 siRNA转染组软琼脂集落形成数明显减少,且与浓度相关(r=0.901,P=0.0005)。琼脂糖凝胶电泳和流式细胞术结果显示,MTA1 siRNA转染可诱导前列腺癌细胞失巢凋亡,且与浓度相关(r=0.916,P=0.0003)。结论:MTA1 siRNA可抑制人前列腺癌细胞增殖,诱导失巢凋亡是其机制之一。     

Receptor‐interacting protein (RIP) and Sirtuin‐3 (SIRT3) are on opposite sides of anoikis and tumorigenesis

BACKGROUND:

Regulating cross‐talk between anoikis and survival signaling pathways is crucial to regulating tissue processes and mitigating diseases like cancer. Previously, the authors demonstrated that anoikis activates a signaling pathway involving the CD95/Fas‐mediated signaling pathway that is regulated by receptor‐interacting protein (RIP), a kinase that shuttles between Fas‐mediated cell death and integrin/focal adhesion kinase (FAK)‐mediated survival pathways. Because it is known that sirtuin‐3 (SIRT3), a nicotinamide adenine dinucleotide‐dependent deacetylase, regulates cell survival, metabolism, and tumorigenesis, the authors hypothesized that SIRT3 may engage in cross‐talk with Fas/RIP/integrin/FAK survival‐death pathways in cancer cell systems.

METHODS:

Using immunohistochemical staining, immunoblotting, human tissue microarrays, and overexpression and suppression approaches in vitro and in vivo, the roles of RIP and SIRT3 were examined in oral squamous cell carcinoma (OSCC) anoikis resistance and tumorigenesis.

RESULTS:

RIP and SIRT3 had opposite expression profiles in OSCC cells and tissues. Stable suppression of RIP enhanced SIRT3 levels, whereas stable suppression of SIRT3 did not impact RIP levels in OSCC cells. The authors observed that, as OSCC cells became anoikis‐resistant, they formed multicellular aggregates or oraspheres in suspension conditions, and their expression of SIRT3 increased as their RIP expression decreased. Also, anoikis‐resistant OSCC cells with higher SIRT3 and low RIP expression induced an increased tumor burden and incidence in mice, unlike their adherent OSCC cell counterparts. Furthermore, stable suppression of SIRT3 inhibited anoikis resistance and reduced tumor incidence.

CONCLUSIONS:

The current results indicted that RIP is a likely upstream, negative regulator of SIRT3 in anoikis resistance, and an anoikis‐resistant orasphere phenotype defined by higher SIRT3 and low RIP expression contributes to a more aggressive phenotype in OSCC development. Cancer 2012. © 2012 American Cancer Society.     

Overexpression of neuropilin-1 promotes constitutive MAPK signalling and chemoresistance in pancreatic cancer cells

Neuropilin-1 (NRP-1) is a novel co-receptor for vascular endothelial growth factor (VEGF). Neuropilin-1 is expressed in pancreatic cancer, but not in nonmalignant pancreatic tissue. We hypothesised that NRP-1 expression by pancreatic cancer cells contributes to the malignant phenotype. To determine the role of NRP-1 in pancreatic cancer, NRP-1 was stably transfected into the human pancreatic cancer cell line FG. Signal transduction was assessed by Western blot analysis. Susceptibility to anoikis (detachment induced apoptosis) was evaluated by colony formation after growth in suspension. Chemosensitivity to gemcitabine or 5-fluorouracil (5-FU) was assessed by MTT assay in pancreatic cancer cells following NRP-1 overexpression or siRNA-induced downregulation of NRP-1. Differential expression of apoptosis-related genes was determined by gene array and further evaluated by Western blot analysis. Neuropilin-1 overexpression increased constitutive mitogen activated protein kinase (MAPK) signalling, possibly via an autocrine loop. Neuropilin-1 overexpression in FG cells enhanced anoikis resistance and increased survival of cells by > 30% after exposure to clinically relevant levels of gemcitabine and 5-FU. In contrast, downregulation of NRP-1 expression in Panc-1 cells markedly increased chemosensitivity, inducing > 50% more cell death at clinically relevant concentrations of gemcitabine. Neuropilin-1 overexpression also increased expression of the antiapoptotic regulator, MCL-1. Neuropilin-1 overexpression in pancreatic cancer cell lines is associated with (a) increased constitutive MAPK signalling, (b) inhibition of anoikis, and (c) chemoresistance. Targeting NRP-1 in pancreatic cancer cells may downregulate survival signalling pathways and increase sensitivity to chemotherapy.     

TrkB、Survivin和Bcl-2在胃癌组织中的表达及意义

[目的]探讨凋亡相关基因TrkB、Survivin和Bcl-2蛋白在胃癌组织中的表达及其与胃癌临床病理学参数的关系。[方法]采用免疫组织化学SP法检测76例原发性胃癌组织和癌旁正常组织TrkB、Survivin和Bcl-2蛋白的表达,并用原位末端标记法检测凋亡指数。[结果](1)胃癌组织中TrkB、Survivin和Bcl-2蛋白的阳性表达率分别为60.53%、73.68%和67.11%,明显高于癌旁正常组织(0.00%、17.11%和22.37%)。TrkB表达与胃癌浸润深度、淋巴结转移和TNM分期有关,Survivin表达与组织学分化、淋巴结转移、TNM分期有关,Bcl-2与组织学分化和TNM分期有关;(2)胃癌平均AI为(2.97±0.37),癌旁正常组织为(9.42±2.87),差异具有显著性意义(P<0.01);TrkB、Survivin和Bcl-2阳性组的AI明显低于阴性组(P<0.05);(3)胃癌组织中TrkB和Survivin的表达呈正相关(r=0.373,P=0.001),Survivin和Bcl-2的表达呈正相关(r=0.345,P=0.002),Bcl-2和TrkB的表达呈正相关(r=...     

Caspase在原发性胆汁性肝硬化患者外周血单个核细胞的表达及其临床意义

目的检测caspase8和caspase3在原发性胆汁性肝硬化（PBC,primary biliary cirrhosis）患者外周血单个核细胞中的表达,探讨其与PBC疾病进展的相关性。方法采用实时荧光定量PCR和免疫印迹法,检测30例PBC和30例正常对照者的外周血单个核细胞（PBMCs）中caspase8和caspase3的基因和蛋白表达。结果PBC患者PBMCs中的caspase8和caspase3的mRNA和蛋白的表达明显低于健康对照组（P〈0.05）。结论PBC患者caspase8,3的表达与疾病的发生发展存在一定的相关性,可以为PBC的诊断和预防提供新线索。