上调Twist基因对人结肠癌SW480细胞增殖凋亡及侵袭能力的影响

目的:上调人结肠癌SW480细胞株中Twist基因的表达,观察其对细胞增殖、凋亡及侵袭能力的影响。方法:将高表达Twist基因的质粒和空载质粒稳定转染SW480细胞,分别命名为转染组和对照组,MTT法、细胞划痕实验和Matrige1侵袭实验分别检测肿瘤细胞体外增殖、迁移及侵袭能力的变化。FCM检测细胞周期及凋亡情况。将肿瘤细胞接种至裸鼠皮下,对比转染前后肿瘤细胞的成瘤情况。结果:从第4天开始,转染组SW480细胞生长速度明显高于对照组(P<0.05):转染组SW480细胞的增殖指数(PI)和S期细胞比例[(61.279±1.709)%,(33.171±3.154)%]均高于对照组[(26.142±1.518)%,(14.112±2.137)%](P<0.05);转染组的细胞凋亡率(6.83I±1.624)%低于对照组(12.223±1.733)%(P<0.05);划痕24 h及48 h时后转染组细胞迁移率[(40.06±5.56)%,(75.77±8.06)%]均高于对照组[(25.25±2.65)%,(35.37±6.79)%](P<0.05);Matrige1侵袭实验结果显示转染组侵袭细胞个数明显高于对照组(p<0.05);将两组细胞分别接种裸鼠,16 d左右可见肿瘤结节,转染组肿瘤体积及瘤重均大于对照组(P<0.05)。结论:上调Twist基因可提高SW480细胞体外增殖、迁移和侵袭能力,降低SW480细胞凋亡率。     

KRT16在胰腺癌中的功能、临床意义及预后价值

目的:研究角蛋白16(keratin 16,KRT16)在胰腺癌细胞系SW1990中的细胞生物学功能。观察KRT16在胰腺癌组织中的表达,分析其表达水平与胰腺癌患者临床病理特征及预后的关系,探讨KRT16在胰腺癌中的临床意义及预后价值,并预测可能的相关机制。方法:分别采用EdU免疫荧光实验、Transwell实验、划痕实验、流式细胞术检测KRT16对SW1990细胞增殖、侵袭、迁移及凋亡的影响。收集并整理2016年01月至2018年12月期间在我院接受手术治疗的56例胰腺癌患者的组织标本及临床病例资料。采用免疫组织化学染色(immunohistochemistry, IHC)检测KRT16蛋白在胰腺癌组织中的表达,统计分析KRT16蛋白表达水平与胰腺癌患者临床病理特征及预后的关系。KRT16相互作用蛋白网络可通过STRING数据库获取,利用基因集富集分析(gene set enrichment analysis, GSEA)预测KRT16在胰腺癌中可能参与的信号通路。结果:细胞功能实验检测结果表明过表达KRT16促进胰腺癌细胞SW1990增殖、侵袭迁移并抑制其凋亡(P<0.001...     

BHLHE40靶向HMGA2激活氧化磷酸化通路降低甲状腺癌细胞对顺铂敏感性的研究

目的探究BHLHE40能否通过靶向高迁移率族蛋白A2(HMGA2)激活氧化磷酸化(OXPHOS)通路进而影响甲状腺癌细胞对顺铂的敏感性。方法通过在线数据库TCGA-甲状腺癌和hTFtarget分析HMGA2及上游转录因子BHLHE40在甲状腺癌组织中的mRNA表达情况。采用脂质体转染法将si-HMGA2、oe-HMGA2、oe-BHLHE40以及阴性对照si-NC、oe-NC转染至甲状腺癌细胞K1和SW579中,通过实时荧光定量PCR检测BHLHE40和HMGA2在甲状腺癌细胞SW579、FTC-133、K1和正常甲状腺细胞Nthy ori3-1中的mRNA表达水平,采用MTT法检测细胞活力,CCK-8法计算顺铂半抑制浓度(IC50)值,流式细胞术检测细胞凋亡水平,蛋白质印迹法检测OXPHOS复合体的表达,Seahorse XFe 96分析细胞的耗氧率。双荧光素酶报告实验和染色质免疫沉淀实验分析BHLHE40与HMGA2的结合关系。结果TCGA数据库结果表明,HMGA2和BHLHE40 mRNA在甲状腺癌组织中的表达(10.57±2.58、13.89±1.13)均较甲状腺正常组织高(4.82±1.69、12.28±1.01),差异均具有统计学意义(t=16.69,P<0.001;t=10.43,P<0.001)。实时荧光定量PCR结果发现,正常甲状腺细胞Nthy ori3-1、甲状腺癌细胞SW579、FTC-133和K1中HMGA2 mRNA相对表达量分别为1.00±0.13、2.94±0.23、4.71±0.41和6.29±0.49,BHLHE40 mRNA相对表达量分别为1.00±0.12、2.60±0.23、3.39±0.35和6.18±0.51,差异均具有统计学意义(F=130.50,P<0.001;F=125.20,P<0.001)。进一步两两比较发现,与正常甲状腺细胞相比,甲状腺癌细胞中HMGA2和BHLHE40 mRNA的表达水平均显著升高(均P<0.001)。MTT法检测显示,与si-NC组相比,si-HMGA2处理显著降低了K1细胞的细胞活力(均P<0.05),oe-HMGA2处理相对于oe-NC组显著增加了SW579细胞的细胞活力(均P<0.05);与oe-NC+DMSO组相比,oe-HMGA2+DMSO组SW579细胞的细胞活力增强,而OXPHOS通路抑制剂Gboxin能够逆转过表达HMGA2对细胞活力的影响(均P<0.05)。流式细胞术和CCK-8实验结果显示,与si-NC组(凋亡水平:6.19%±0.28%;顺铂IC50值:17.47μmol/L)相比,敲低HMGA2能增加K1细胞的凋亡水平(11.96%±0.32%;t=19.17,P<0.001)和顺铂敏感性(IC50值:1.49μmol/L);与oe-NC组(凋亡水平:9.98%±0.32%;顺铂IC50值:8.17μmol/L)相比,过表达HMGA2显著降低了SW579细胞凋亡水平(4.32%±0.25%;t=19.65,P<0.001)和顺铂敏感性(IC50值:34.95μmol/L)。双荧光素酶报告实验结果发现,与si-NC组相比,在人肾上皮细胞293T细胞中敲低BHLHE40的表达显著降低野生型HMGA2的荧光素酶活性(0.31±0.02比1.00±0.11;t=10.69,P=0.004),但对于突变型HMGA2的荧光素酶活性没有显著性影响(1.06±0.11比1.00±0.07;t=0.80,P=0.470)。染色质免疫沉淀实验结果显示,与IgG组(1.00±0.10)相比,anti-BHLHE40组K1细胞的HMGA2 mRNA表达水平显著增加(6.57±0.62;t=15.36,P<0.001)。与oe-NC+DMSO组相比,oe-HMGA2+DMSO组SW579细胞凋亡水平(P<0.05)和顺铂敏感性均降低,OXPHOS复合体Ⅰ~Ⅴ表达显著增强,细胞耗氧率升高(均P<0.05),oe-HMGA2+Gboxin处理可逆转过表达HMGA2的影响(均P<0.05)。回复实验表明,与oe-NC+si-NC组相比,过表达BHLHE40后SW579细胞的细胞活力和OXPHOS复合体Ⅰ~Ⅴ的表达增强,细胞耗氧率和顺铂IC50值显著增加,细胞凋亡水平下降(均P<0.05);而同时敲低HMGA2可逆转过表达BHLHE40的影响(均P<0.05)。结论BHLHE40可通过靶向调控HMGA2的表达激活氧化磷酸化通路,进而影响甲状腺癌细胞对顺铂的敏感性。     

长链非编码RNA MEG3靶向miR-21对胶质瘤U251细胞增殖、侵袭和迁移的影响

摘 要：［目的］ 探究长链非编码RNA人母系表达基因3 (maternally expressed gene 3,MEG3)对人胶质瘤细胞U251增殖、侵袭和迁移能力的影响及机制。［方法］ RT-PCR检测MEG3和miR-21在胶质瘤组织、癌旁组织中、正常星形胶质细胞NHAs和胶质瘤细胞U251中的表达;用pcDNA-MEG3 (pc-MEG3)转染U251细胞,RT-PCR检测MEG3和miR-21的表达;生物信息及荧光素酶报告实验预测并验证MEG3和miR-21的关系;MTT检测细胞增殖能力,Transwell和划痕实验检测细胞侵袭和迁移能力;免疫印迹检测增殖细胞核抗原 (proliferating cell nuclear antigen,PCNA)、基质金属蛋白酶-2(metalloproteinase-2,MMP-2) 和MMP-9的表达。［结果］ 与癌旁组织比较,MEG3在胶质瘤组织中表达水平明显降低(t=23.169,P<0.001),miR-21水平明显升高(t=14.965,P=0.002);与NHAs组比较,U251组细胞MEG3表达水平明显降低(t=13.145,P<0.001),miR-21表达水平显著升高（t=12.483,P<0.001);pcMEG3 能显著上调MEG3的表达水平并抑制miR-21表达(t=8.129,P<0.001;t=11.705,P<0.001);miR-21 mimic能显著促进miR-21表达并能降低MEG3 野生质粒 (MEG3 wt) 的活性(t=6.460,P<0.001;t=7.742,P=0.004);pc-MEG3能显著降低U251细胞增殖倍数和PCNA的表达水平(F=96.45,P<0.001;t=5.337,P<0.001),miR-21 mimic能显著减弱pc-MEG3对细胞增殖及PCNA表达的抑制作用(t=7.073,P<0.001;t=4.609,P<0.001);同时,pc-MEG3还能显著降低U251细胞的划痕闭合率和侵袭细胞数(t=5.014,P<0.001;t=10.664,P<0.001),并抑制MMP-2和MMP-9的表达(t=3.360,P=0.007;t=3.453,P=0.006）;miR-21 mimic能明显减弱pc-MEG3对细胞侵袭、迁移及MMP-2和MMP-9表达的抑制作用(t=2.498,P=0.032;t=4.298,P=0.002;t=4.612,P<0.001;t=5.137,P<0.001)。［结论］ MEG能通过靶向miR-21减弱胶质瘤U251细胞的增殖、侵袭和迁移能力。     

NDRG2基因对结肠癌细胞SW620增殖和侵袭力的影响

目的 观察N-myc下游调节基因2(NDRG2)对结肠癌细胞SW620生长和侵袭能力的影响,并探讨其机制.方法 采用阳离子脂质体转染方法,分别将pcDNA3.1-NDRG2和siRNA-NDRG2转染入SW620细胞内,以空白组作为对照.Western blotting检测各组细胞NDRG2以及基质金属蛋白酶-2(MMP-2)的表达情况;细胞侵袭试验对各组细胞侵袭能力进行分析;四甲基偶氮唑蓝法对各组细胞生长曲线进行测定.结果 pcDNA3.1-NDRG2转染入SW620细胞后,NDRG2蛋白表达升高,而MMP-2蛋白表达降低;siRNA-NDRG2转染入SW620细胞后,NDRG2蛋白表达降低,而MMP-2蛋白表达升高.pcDNA3.1组的穿膜细胞数(56.20±7.40)及siRNA组穿膜细胞数(94.20 ±9.23)分别与对照组(75.80 ±4.82)相比,差异具有统计学意义(t=13.102,P=0.000;t=11.820,P=0.000).生长曲线显示,转染后第5天,pcDNA3.1组细胞吸光度值(0.46 ±0.01)及siRNA组细胞吸光度值(0.91 ±0.02)分别与对照组(0.67 ±0.01)相比,差异具有统计学意义(t=9.561,P=0.000;t=10.922,P=0.000).结论 NDRG2能降低结肠癌细胞SW620的侵袭和增殖能力,其机制可能与下调MMP-2的表达有关.     

miR-4319通过靶向调控USP2抑制乳腺癌细胞侵袭

目的探讨miR-4319与泛素特异性蛋白酶2(USP2)表达的相关性以及miR-4319靶向USP2通过核转录因子κB(NF-κB)信号通路对乳腺癌细胞侵袭的影响。方法实时荧光定量PCR(qRT-PCR)检测miR-4319在正常乳腺癌上皮细胞(MCF10A)、低侵袭性乳腺癌细胞(MCF7)和高侵袭性乳腺癌细胞(MDA-MB-231)中的表达量。将MCF10A、MCF7和MDA-MB-231细胞分为6组进行转染:(1)MDA-MB-231/NC组,瞬时转染插入一段乱码序列(scramble 1),即作为miR-4319过表达对照质粒;(2)MDA-MB-231/miR-4319组,瞬时转染插入目的片段miR-4319质粒过表达miR-4319,即miR-4319过表达;(3)MDA-MB-231/miR-4319+Con组,瞬时转染同时转入miR-4319过表达质粒和USP2过表达对照质粒,即miR-4319过表达以及USP2过表达对照;(4)MDA-MB-231/miR-4319+USP2组,瞬时转染同时转入miR-4319过表达质粒和USP2过表达质粒,即miR-4319过表达和USP2过表达;(5)MDA-MB-231/miR-4319inhibitor组,瞬时转染miR-4319的反义序列抑制miR-4319的表达,即抑制miR-4319的表达;(6)MDA-MB-231/miR-4319inhibitor NC组,瞬时转染插入一段乱码序列(scramble 2),即作为抑制miR-4319组的对照组。qRT-PCR检测miR-4319在MDA-MB-231细胞中的转染效率。荧光素酶实验检测miR-4319与USP2 mRNA是否存在结合位点。qRT-PCR检测miR-4319在乳腺癌细胞中过表达后的USP2 mRNA表达水平。蛋白质印迹法检测过表达miR-4319或抑制miR-4319表达后的USP2蛋白表达水平。Transwell侵袭实验检测过表达miR-4319或USP2后MDA-MB-231细胞侵袭能力。双荧光素酶实验检测miR-4319对NF-κB信号通路活性的影响以及过表达USP2后miR-4319对NF-κB信号通路活性的影响。结果 qRT-PCR结果显示,miR-4319相对表达量在细胞MDA-MB-231(t=14.860,P<0.001)和MCF7(t=12.770,P<0.001)中分别为0.330±0.075和0.570±0.082,均低于细胞MCF10A(1.012±0.051);miR-4319相对表达量MDA-MB-231/miR-4319组(3.980±0.083)高于MDA-MB-231/NC组(1.009±0.058),差异有统计学意义,t=102.90,P<0.001。荧光素酶实验结果显示,pGL3-USP2 3’-UTR-WT报告载体与miR-4319质粒共转染后的荧光素酶活性下降,差异有统计学意义,t=15.740,P<0.001。qRT-PCR结果显示,USP2 mRNA相对表达量MDA-MB-231/NC组(1.013±0.058)和MDA-MB-231/miR-4319组(0.988±0.062)基本没有变化,差异无统计学意义,t=1.201,P=0.296。而蛋白质印迹法结果显示,USP2蛋白相对表达量miR-4319组(0.371±0.083)低于miR-4319/NC组(1.003±0.064),miR-4319/inhibitor组(1.982±0.093)高于inhibitor/NC组(1.104±0.072),USP2蛋白相对表达量的组间比较差异有统计学意义,F=212.4,P<0.001。Transwell侵袭实验结果显示,穿过Matrigel细胞数MDA-MB-231/miR-4319组(58.337±5.972)低于MDA-MB-231/NC组(192.371±5.476),差异有统计学意义,t=29.720,P<0.001;穿过Matrigel细胞数MDA-MB-231/miR-4319+USP2组(167.197±8.292)高于MDA-MB-231/miR-4319+Con组(63.283±10.397),差异有统计学意义,t=14.150,P=0.001。双荧光素酶结果显示,miR-4319/NF-κB-luc组荧光素酶活性(0.324±0.06)低于NC/pRL-TK组(1.024±0.080)、NC/NF-κB-luc组(2.023±0.110)和miR-4319/pRL-TK组(1.109±0.050),组间比较差异有统计学意义,F=237.1,P<0.001;miR-4319+USP2/NF-κB-luc组荧光素酶活性(2.032±0.12)高于miR-4319+USP2/pRL-TK组(1.094±0.100)、miR-4319+Con/pRL-TK组(1.063±0.080)和miR-4319+Con/NF-κB-luc组(0.334±0.050),组间比较差异有统计学意义,F=164.2,P<0.001。结论 miR-4319在乳腺癌细胞中低表达,miR-4319靶向结合USP2,过表达USP2逆转了miR-4319对乳腺癌细胞侵袭能力的抑制作用和NF-κB转录活性的抑制作用。miR-4319通过靶向结合USP2抑制NF-κB信号通路,从而抑制乳腺癌细胞的侵袭。     

蟾毒灵抑制人结肠癌HCT116细胞侵袭机制探讨

目的 肿瘤侵袭转移的发生是影响结肠癌治疗的重要原因,结肠癌细胞黏附能力的下降以及迁移能力的增强是促进结肠癌细胞侵袭转移的重要原因.有研究发现,蟾毒灵具有抑制结肠癌细胞侵袭能力的作用,但其作用机制尚不明确.本研究探讨蟾毒灵对人结肠癌HCT116细胞侵袭的影响,并探索其可能的作用机制.方法 用蟾毒灵溶液干预结肠癌HCT116细胞,采用细胞划痕实验与细胞黏附实验检测蟾毒灵溶液对结肠癌HCT116细胞侵袭能力的影响;ELISA法检测蟾毒灵溶液干预结肠癌HCT116细胞培养基中细胞外泌TGFβ1蛋白的含量;蛋白质印迹法检测蟾毒灵干预后结肠癌HCT116细胞中P-smad3、smad4和钙黏链蛋白(E-cadherin)表达的变化;免疫荧光实验检测蟾毒灵干预后各组HCT116细胞中P-smad3与smad4蛋白表达的变化.结果 细胞划痕实验结果显示,低、中、高剂量蟾毒灵均可降低HCT116细胞迁移能力;细胞黏附实验显示,对照组、低剂量组、中剂量组和高剂量组黏附细胞平均值分别为833.33±7.80、877.00±17.75、1 304.00±15.82和1 406.00±20.53,相对黏附率分别为100％、105.24％、156.48％和168.73％,差异有统计学意义,x2 =297.597,P＜0.001.ELISA检测结果显示,对照组、低、中和高剂量细胞培养液中转化生长因子β(transforming growth factor-β,TGFβ1)蛋白含量分别为(1 198.78±38.96)、(1 106.58±35.76)、(1 040.80±47.47)和(987.74±37.52) pg/mL,F=16.357,P=0.005.蛋白质印迹法检测结果显示,与对照组相比,中、高剂量蟾毒灵处理后HCT116细胞中P-smad3表达呈现明显下降;而smad4蛋白表达明显上调,组间差异有统计学意义,F=56.993,P＜0.001;低剂量蟾毒灵也可上调smad4蛋白的表达,t=5.342,P=0.006.各用药组HCT116细胞中E-cadherin蛋白的表达水平也随着蟾毒灵剂量的增加而增加,分别为对照组的2.514±0.385(t=4.833,P=0.008)、3.524±0.397(t=9.200,P=0.001)和3.937±0.318(t=10.675,P＜0.001)倍;免疫荧光法检测发现,蟾毒灵处理后结肠癌HCT116细胞中P-smad3与smad4蛋白的表达呈现出与蛋白质印迹法检测相似的趋势.结论 蟾毒灵可通过抑制TGFβ1/smad信号通路的信号传导抑制结肠癌HCT116细胞的侵袭.     

反义肝素酶cDNA对裸鼠人胰腺癌移植瘤生长和血管生成的抑制作用

目的研究反义肝素酶cDNA对裸鼠人胰腺癌SW1990细胞移植瘤生长和血管生成的抑制作用。方法将反义肝素酶cDNA转染成功的人胰腺癌SW1990细胞注射于裸鼠皮下建立移植瘤模型。观察移植瘤生长曲线、抑瘤率,以免疫组化方法检测移植瘤肝素酶表达和肿瘤微血管密度,比较反义组、空载体组和空白对照组的差异。结果反义组成瘤时间晚,瘤体大小较对照组小,t=4.11,P=0.00,抑瘤率在第6周时达64.2%。反义组、空载组和空白组移植瘤的免疫组化染色评分(IHS)分别为3.8±1.2、9.5±2.3和10.2±2.0,反义组与对照组比较,IHS明显降低,t=6.72,P=0.00。MVD计数分别为18.6±2.2,33.3±5.3和34.9±3.2条,与对照组比较,MVD明显降低t=10.28,P=0.00。结论反义肝素酶cDNA抑制裸鼠人胰腺癌移植瘤生长和血管生成,有希望成为一种有效的胰腺癌基因治疗方法。     

Irinotecan and radiation in vitro and in vivo

Loss of chromosome sequences at 13q14 (Rbl) and 17p13 (p53) associated with squamous cell carcinoma of head and neck (SCCHN) was evaluated in 12 recurrent tumors and 51 primary tumors from 63 patients. The incidence of LOH at 17p13 was 19 of 50 (38%) tumors, and at 13q14 was 21 of 57 (37%). LOH affecting Rbl and/or p53 was observed in 30 of 63 (48%) SCCHN. Coincident LOH at Rbl and p53 was detected in 10 of 46 (22%) tumors. There were nine cases in which primary and metastatic tumors were obtained from the same patient. Of these, seven were informative and five of these (71%) manifested LOH at p53 in both primary and metastatic sites. Examination of Rbl in these same tumors showed LOH in six of the nine metastases, and of these six, only three revealed LOH in the primary tumor. LOH at p53 or Rbl alone showed no correlation with clinical outcome. However, tumors that manifested LOH at both loci were associated with poorer patient outcome and poorer histological differentiation.     

Daunorubicin and daunorubicinol pharmacokinetics in plasma and tissues in the rat

Recent evidence suggests that 13-hydroxy metabolites of anthracyclines may contribute to cardiotoxicity. This study was designed to determine the pharmacokinetics of daunorubicin and the 13-hydroxy metabolite daunorubicinol in plasma and tissues, including the heart. Fisher 344 rats received 5 mg kg^–1 daunorubicin i.v. by bolus injection. Rats were killed at selected intervals for up to 1 week after daunorubicin administration for determination of concentrations of daunorubicin and daunorubicinol in the plasma, heart, liver, kidney, lung, and skeletal muscle. Peak concentrations of daunorubicin were higher than those of daunorubicinol in the plasma (133±7 versus 36±2 ng ml^–1;P<0.05), heart (15.2±1.4 versus 3.4±0.4 g g^–1;P<0.05), and other tissues. However, the apparent elimination half-life of daunorubicinol was longer than that of daunorubicin in most tissues, including the plasma (23.1 versus 14.5 h) and heart (38.5 versus 19.3 h). In addition, areas under the concentration/time curves (AUC) obtained for daunorubicinol exceeded those found for daunorubicin in almost all tissues, with the ratios being 1.9 in plasma and 1.7 in the heart. The ratio of daunorubicinol to daunorubicin concentrations increased dramatically with time from <1 at up to 1 h to 87 at 168 h in cardiac tissue. Thus, following daunorubicin injection, cumulative exposure (AUC) to daunorubicinol was greater than that to daunorubicin in the plasma and heart. If daunorubicinol has equivalent or greater potency than daunorubicin in causing impairment of myocardial function, it may make an important contribution to the pathogenesis of cardiotoxicity.     

TCP and NTCP in preclinical and clinical research in Europe

European research in radiation oncology has a long and successful tradition. The aim of this research is to increase the therapeutic window of radiotherapy by increasing the tumor control probability (TCP) and/or by decreasing the normal tissue complication probability (NTCP). This paper summarizes the basic radiobiological concept underlying treatment optimization by TCP-NTCP data and discusses some of the limitations of currently used models. These are controversial in many aspects and cannot be recommended for clinical routine practice but should rather be considered as a research tool.     

Foscan and foslip based photodynamic therapy in osteosarcoma in vitro and in intratibial mouse models

Current osteosarcoma therapies cause severe treatment‐related side effects and chemoresistance, and have low success rates. Consequently, alternative treatment options are urgently needed. Photodynamic therapy (PDT) is a minimally invasive, local therapy with proven clinical efficacy for a variety of tumor types. PDT is cytotoxic, provokes anti‐vascular effects and stimulates tumor cell targeting mechanisms of the immune system and, consequently, has potential as a novel therapy for osteosarcoma patients. This study investigated the uptake and the dark‐ and phototoxicity and cytotoxic mechanisms of the photosensitizer (PS) 5,10,15,20‐tetrakis(meta‐hydroxyphenyl) chlorine (mTHPC, Foscan) and a liposomal mTHPC formulation (Foslip) in the human 143B and a mouse K7M2‐derived osteosaroma cell line (K7M2L2) in vitro. Second, the tumor‐ and metastasis‐suppressive efficacies of mTHPC formulations based PDT and associated mechanisms in intratibial, metastasizing osteosarcoma mouse models (143B/SCID and syngeneic K7M2L2/BALB/c) were studied. The uptake of Foscan and Foslip in vitro was time‐ and dose‐dependent and resulted in mTHPC and light dose‐dependent phototoxicity associated with apoptosis. In vivo, the uptake of both i.v. administered mTHPC formulations was higher in tumor than in healthy control tissue. PDT caused significant (Foscan p < 0.05, Foslip p < 0.001) tumor growth inhibition in both models. A significant (Foscan p < 0.001, Foslip p < 0.001) immune system‐dependent suppression of lung metastasis was only observed in the K7M2L2/BALB/c model and was associated with a marked infiltration of T‐lymphocytes at the primary tumor site. In conclusion, mTHPC‐based PDT is effective in clinically relevant experimental osteosarcoma and suppresses lung metastasis in immunocompetent mice with beneficial effects of the liposomal mTHPC formulation Foslip.     

Serum ghrelin and esophageal and gastric cancer in two cohorts in China

Ghrelin is a hormone produced in the oxyntic glands of the stomach. Previous work by our group has suggested that serum ghrelin concentrations are inversely associated with gastric and esophageal cancer risk. We measured ghrelin concentrations in the Linxian General Population Nutrition Intervention Trial (NIT), and the Shanghai Women's Health Study (SWHS). In NIT, we analyzed serum samples from 298 esophageal squamous cell carcinoma (ESCC) cases, 518 gastric cardia adenocarcinoma (GCA) cases, 258 gastric noncardia adenocarcinoma (GNCA) cases and 770 subcohort controls (case–cohort). In SWHS, we measured ghrelin in plasma samples from 249 GNCA cases and 498 matched controls (nested case–control). Ghrelin was measured using radioimmunoassay. In NIT and SWHS, low ghrelin concentrations were associated with an increased risk of developing GNCA and GCA. The hazard ratio (HR _Q1:Q4) for GNCA in NIT was 1.35 (95% CI: 0.89–2.05; p-trend = 0.02); the odds ratio in SWHS was 1.66 (95% CI: 1.02–2.70; p-trend = 0.06). Low ghrelin was associated with a twofold increase of GCA (HR _Q1:Q4 = 2.00, 95% CI: 1.45–2.77; p-trend<0.001). In contrast, a lower risk of ESCC (NIT ESCC HR _Q1:Q4 = 0.65, 95% CI: 0.45–0.92; p-trend = 0.02) was found in NIT. Low baseline ghrelin concentrations were associated with an increased risk for GNCA and GCA in the NIT and the SWHS. In contrast, low ghrelin concentrations at baseline were associated with a reduced risk of developing ESCC in the NIT. Ghrelin may be an early marker of future cancer risk for developing upper gastrointestinal cancer in regions of high incidence.     

Hyperthermia and platinum complexes: Time between treatments and synergy in vitro and in vivo

To investigate the greatest therapeutic efficacy, we investigated the effect of scheduling on the cytotoxic interaction between hyperthermia and seven different platinum complexes in vitro and in vivo using the FSaII murine fibrosarcoma cells. Hyperthermia treatment (43°C, 1 h) was administered at various times relative to exposure of the cells to the IC₉₀ (at 37°C, 1 h) of each platinum complex. Greater-than-additive killing of FSaII cells was obtained with cis-diamminedichloroplatinum (II) (CDDP) and hyperthermia when the drug and heat exposure were overlapping or simultaneous. The same cell killing effect with carboplatin and hyperthermia resulted from heat exposure up to 5 h prior to, simultaneous with, or immediately after the drug exposure. D-Tetraplatin and K₂PtCl₄ were synergistic with hyperthermia only if the drug and heat exposure were simultaneous. PtCl₄(Nile Blue)₂ and hyperthermia produced greater-than-additive cell killing if the heat and drug exposure occurred in immediate sequence, simultaneously, or with drug exposure up to 5 h prior to heat exposure. PtCl₄(Rh-123)₂ and hyperthermia produced greater-than-additive cell killing if the drug and heat occurred in immediate sequence, overlapping, or simultaneously. PtCl₄(Fast Black)₂ and hyperthermia were additive over a wide range of scheduling from heat exposure 2 h prior to 5 h after drug exposure. When animals bearing FSaIIC tumours were treated with single doses of CDDP (10 mg/kg), carboplatin/PtCl₄(Nile Blue)₂ (50 mg/kg), PtCl₄(Rh-123)₂/PtCl₄(Fast Black)₂ (100 mg/kg) under various combined schedules with hyperthermia treatment (43°C, 30 min), similar cytotoxicity patterns were observed. To administer hyperthermia at a time when the drug concentration in the tumour tissue is at peak level, careful scheduling of systemically administered anticancer drugs with hyperthermia is needed. Modelling studies can identify the stringency/flexibility of drug/heat scheduling to achieve synergistic tumour cell killing.     

ARHI在肿瘤发生和发展中的作用与机制研究进展

ARHI是1999年发现的母源性印迹基因,属于小G蛋白Ras超家族,是该家族第1个被报道的抑癌基因。ARHI的功能包括抑制小鼠生长和生殖发育,抑制细胞增殖、迁移,参与周期调控和凋亡,近年来研究发现ARHI还具有调控肿瘤细胞自噬、抑制肿瘤转移的作用。ARHI蛋白在人体卵巢、乳腺等多种组织中表达,在卵巢癌、乳腺癌、甲状腺癌、胰腺癌、肝癌组织中表达下调,ARHI基因高表达可提示卵巢癌、胰腺癌的预后良好。ARHI表达调控机制包括杂合性丢失、DNA甲基化、组蛋白去乙酰化、转录因子调节、miRNA和突变,应用表观遗传学技术调节ARHI表达可能在一些肿瘤中具有抗肿瘤临床应用价值。ARHI基因参与调节肿瘤细胞休眠过程,有望成为诱导肿瘤细胞休眠、抗肿瘤转移复发的关键点。     

Fibronectin and integrins in invasion and metastasis

Summary The adhesive glycoprotein fibronectin and integrin receptors appear to play important roles in the progression of metastatic disease. Fibronectin is a multifunctional extracellular glycoprotein that has at least two independent cell adhesion regions with different receptor specificities. The cell adhesive region in the central portion of fibronectin is comprised of at least two minimal amino acid sequences - an Arg-Gly-Asp (RGD) sequence and a Pro-His-Ser-Arg-Asn (PHSRN) sequence - which function in synergy. Another cell adhesive region is located near the carboxy-terminus in the alternatively spliced IIICS module. The critical minimal sequences for this region are Leu-Asp-Val (LDV) and Arg-Glu-Asp-Val (REDV) which function in an additive rather than synergistic fashion. Integrins are heterodimeric, transmembrane cell adhesion receptors for fibronectin and other extracellular matrix molecules. Several different integrins bind to fibronectin. The ₅₁ fibronectin-specific integrin binds to the central RGD/PHSRN site. The ₄₁ integrin binds to the IIICS site. Fibronectin-integrin interactions are important in tumor cell migration, invasion, and metastasis. In addition to promoting cell adhesion to the extracellular matrix, these proteins may also function in chemotaxis and control of proliferation. Peptide and antibody inhibitors of fibronectin and integrin functions have been shown to be effective inhibitors of metastasis, and are potentially important reagents for the study and control of cancer.     

Racial Differences in Oral and Pharyngeal Cancer Treatment and Survival in Florida

OBJECTIVE: This study examined racial differences in treatment and survival for blacks and whites in Florida diagnosed with oral or pharyngeal cancer. METHODS: Data for 21,481 malignancies of the oral cavity or pharynx diagnosed from 1988 to 1998 were derived from the Florida Cancer Data System. Type of cancer treatment was compared by race, stratified by anatomic site and summary stage at diagnosis. Kaplan-Meier survival curves were used to compare survival rates and Cox regression models were used to estimate hazard ratios for race. Covariates included age, sex, census tract income, and treatment. RESULTS: Stratifying by tumor site and stage, blacks consistently had poorer survival rates than whites. Across tumor stages, blacks with oral cavity cancer were consistently more likely than whites to have received only radiotherapy and less likely to have received cancer-directed surgery. Trends were similar for pharyngeal cancer, although statistically significant only for regional stages. Across site and stage, blacks consistently had elevated hazard ratios (range: 1.20-1.53) relative to whites. CONCLUSIONS: In Florida, there were racial differences in patient treatment for oral or pharyngeal cancer. Blacks had lower survival rates than whites, but differences in treatment did not entirely account for racial disparities in survival.