黏着斑激酶基因沉默促进舌癌细胞失巢凋亡的实验研究

目的观察黏着斑激酶(focal adhension kinase,FAK)基因沉默对口腔舌癌细胞株Tca8113失巢凋亡抗性的影响,探讨FAK基因与口腔鳞癌转移特性的关系。方法以舌癌细胞株Tca8113为研究对象,首先应用免疫细胞化学和免疫蛋白印记的方法检测FAK基因的表达,然后利用RNA干扰的方法抑制FAK基因的表达。最后利用悬浮培养、流式细胞仪的方法观察FAK对口腔舌癌细胞株Tca8113体外培养过程抗失巢凋亡的影响。结果舌癌细胞株Tca8113体外培养过程中具有较强的抗失巢凋亡特性。特异性siRNA可以抑制FAK基因的表达。FAK基因干扰后,Tca8113细胞的失巢凋亡显著提高(P<0.01)。结论FAK基因沉默可以逆转舌癌细胞株Tca8113体外培养过程中的抗失巢凋亡特性。     

Macrolide analog F806 suppresses esophageal squamous cell carcinoma (ESCC) by blocking β1 integrin activation

The paucity of new drugs for the treatment of esophageal squamous cell carcinoma (ESCC) limits the treatment options. This study characterized the therapeutic efficacy and action mechanism of a novel natural macrolide compound F806 in human ESCC xenograft models and cell lines. F806 inhibited growth of ESCC, most importantly, it displayed fewer undesirable side effects on normal tissues in two human ESCC xenograft models. F806 inhibited proliferation of six ESCC cells lines, with the half maximal inhibitory concentration (IC₅₀) ranging from 9.31 to 16.43 μM. Furthermore, F806 induced apoptosis of ESCC cells, contributing to its growth-inhibitory effect. Also, F806 inhibited cell adhesion resulting in anoikis. Mechanistic studies revealed that F806 inhibited the activation of β1 integrin in part by binding to a novel site Arg610 of β1 integrin, suppressed focal adhesion formation, decreased cell adhesion to extracellular matrix and eventually triggered apoptosis. We concluded that F806 would potentially be a well-tolerated anticancer drug by targeting β1 integrin, resulting in anoikis in ESCC cells.     

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.     

3-methyladenine抑制自噬诱导胰腺癌细胞SW1990失巢凋亡

【目的】 探讨3-methyladenine(3-MA)对人胰腺癌SW1990细胞增殖?迁移及失巢凋亡的影响作用及其机制?【方法】 以胰腺癌细胞SW1990及永生化胰腺导管上皮细胞H6C7为研究对象,设3-MA处理组及PBS对照组,采用软琼脂克隆培养法及Poly-HEMA悬浮培养法筛选抵抗失巢凋亡的细胞?Annexin V-FITC/PI双染和TUNEL试剂盒法检测细胞凋亡;免疫荧光法及透射电镜检测细胞自噬;CCK-8法检测细胞增殖; Transwell小室检测细胞迁移能力?【结果】永生化胰腺导管上皮细胞H6C7处理组及对照组均无集落形成,胰腺癌细胞SW1990处理组形成(2.3 ± 2.63)个集落,对照组形成(9 ± 3)个,与H6C7 相比,SW1990具有较强的抵抗失巢凋亡的能力 (P < 0.05)?3-MA可抑制胰腺癌SW1990细胞自噬(P < 0.05)并抑制其增殖及迁移能力(P < 0.01)且诱导失巢凋亡(P < 0.01)?【结论】 3-MA可诱导胰腺癌细胞SW1990失巢凋亡,其机制可能与细胞自噬受抑有关?     

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=...     

肺腺癌A549细胞抗失巢凋亡相关基因的确认及C8orf4基因的表达

目的:比较抗失巢凋亡及正常贴壁生长肺腺癌A549细胞基因组表达差异,从中筛选肺癌抗失巢凋亡相关基因,并探讨C8orf4基因的高表达及其对失巢凋亡的正性调剂作用意义。方法:建立抗失巢凋亡肺癌A549细胞系;用基因芯片技术检测其与正常贴壁生长A549细胞的差异基因,利用NCBI Pubmed数据库筛选出肺癌细胞抗失巢凋亡相关的基因,找出差异表达倍数最大的基因,运用逆转录聚合酶链反应(RT-PCR)技术及蛋白质印迹技术测定其表达。结果:共检测到表达差异的基因745个,筛选出63个与肺癌细胞抗失巢凋亡相关的基因,C8orf4基因差异表达倍数最大,在脱落培养A549细胞中C8orF4基因及其编码蛋白表达明显高于贴壁培养A549细胞,P<0.02。结论:基因芯片技术为筛选肺癌抗失巢凋亡相关基因提供了有效方法,C8ORF4基因可能参与调控肺癌细胞抗失巢凋亡过程。     

EGFR激活对头颈部鳞癌细胞SCC10A抗失巢凋亡的影响

目的探讨表皮生长因子（EGF）对头颈部鳞癌细胞SCC10A失巢凋亡的影响及其机理。方法运用悬浮诱导凋亡试验检测EGF受体（EGFR）激活后对头颈部鳞癌细胞SCC10A抗失巢凋亡能力的影响;Real-time PCR和West blotting检测Bcl-2和Bcl-xl表达情况。结果 EGFR激活后提高了头颈部鳞癌细胞SCC10A抗失巢凋亡的能力;诱导了Bcl-2和Bcl-xl的表达。结论 EGF能提高头颈部鳞癌细胞SCC10A抗失巢凋亡能力。     

Bcl2转录抑制因子1、E-钙黏蛋白在宫颈鳞状细胞癌不同区域的表达及两者与P16INK4a表达的关系

目的 检测宫颈鳞状细胞癌肿瘤出芽区及肿瘤中央区失巢凋亡因子Bcl2转录抑制因子1（Bit1）、上皮-间质转化（EMT）标志物E-钙黏蛋白及P16^INK4a的表达情况,探讨Bit1、E-钙黏蛋白在宫颈癌获得高侵袭力过程中的意义及二者与P16^INK4a表达的关系。方法 收集甘肃省肿瘤医院病理科2014-2018年宫颈鳞状细胞癌石蜡包埋标本77例。采用免疫组织化学法检测宫颈鳞状细胞癌肿瘤出芽区及中央区Bit1、E-钙黏蛋白、P16^INK4a的表达情况。以肿瘤中央区及出芽区各蛋白质表达评分的中位数作为分界点,将标本分为高表达组和低表达组,分析在不同P16^INK4a表达情况下Bit1及E-钙黏蛋白的表达差异及二者与患者临床病理特征的关系,并进一步分析在肿瘤中央区及出芽区Bit1与E-钙黏蛋白的相关关系。统计学分析采用χ²检验或连续校正χ²检验和Spearman等级相关分析。结果 77例宫颈鳞状细胞癌标本中,肿瘤中央区P16^INK4a、E-钙黏蛋白、Bit1高表达率分别为32.5%（25/77）、67.5%（52/77）、63.6%（49/77）,而在肿瘤出芽区分别为67.5%（52/77）、33.8%（26/77）、37.7%（29/77）,差异有统计学意义（χ²=18.935、17.561、10.391,P均<0.01）。无论在肿瘤出芽区还是中央区,P16^INK4a高表达组与P16^INK4a低表达组Bit1及E-钙黏蛋白的表达差异均无统计学意义（P均>0.05）。肿瘤中央区Bit1低表达与脉管内癌栓及淋巴结转移有关（χ²=5.053、4.400,P均<0.05）,肿瘤出芽区E-钙黏蛋白和Bit1低表达均与淋巴结转移有关（χ²=5.580、7.573,P均<0.05）。Spearman等级相关分析显示,在肿瘤中央区及肿瘤出芽区E-钙黏蛋白与Bit1表达均呈正相关（r=0.287,P=0.011;r=0.236,P=0.039）。结论 宫颈癌侵袭力的增高与Bit1及E-钙黏蛋白表达降低及P16^INK4a表达增高有关,宫颈癌细胞可能通过抑制Bit1获得失巢凋亡抗性并影响EMT的发生从而获得更高的侵袭能力,但P16^INK4a并未参与此过程。     

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。