HA-CD44st-TGF-β信号通路对乳腺癌MCF-7细胞HER2表达及侵袭能力的影响

目的探讨HA-CD44st-TGF-β信号通路对人乳腺癌细胞株MCF-7细胞HER2表达及侵袭能力的影响。方法应用脂质体转染法将真核表达载体pcDNA3.1-CD44st转染入MCF-7细胞中,以该转染细胞株(MCF-7/CD44st)为基础,采用逆转录聚合酶链反应(RT-PCR)、流式细胞术及Western blot检测mRNA及相关蛋白的表达,电泳迁移率变动分析(EMSA)检测激活蛋白-1(AP-1)的活性,Transwell法检测HA-CD44st→TGF-β信号通路对MCF-7细胞侵袭能力的影响。结果 MCF-7细胞转染pcDNA3.1-CD44st后,CD44 mRNA和CD44蛋白的表达水平升高;透明质酸(HA)处理后,MCF-7/CD44st细胞中人表皮生长因子受体2(HER2)、转化生长因子-β(TGF-β)、磷酸化蛋白激酶B(p-AKT)表达水平明显升高,转录因子AP-1活性增强,侵袭细胞数量增多。结论 HA与CD44st受体结合后,可以通过HA-CD44st→TGF-β信号转导通路调节HER2基因表达并增强MCF-7细胞的侵袭能力。     

TNF-α对人乳腺癌MCF-7细胞株CD44表达以及细胞侵袭性的影响

目的:检测TNF-α作用前后人乳腺癌细胞株MCF-7中CD44s、CD44v3和CD44v6的表达水平的变化,及对细胞侵袭能力的影响.方法:采用RT-PCR和Western blot方法检测TNF-α作用前后人乳腺癌细胞株MCF-7中CD44s、CD44v3和CD44v6的表达情况,了解TNF-α对CD44各亚型表达水平的影响;Transwell检测TNF-α作用前后人乳腺癌细胞株MCF-7侵袭力的变化情况.结果:TNF-α作用后,MCF-7细胞株CD44s mRNA表达下降,CD44v3 mRNA和CD44v6 mRNA的表达上升.相应蛋白表达与mRNA水平呈现一致性改变,其中CD44s蛋白表达下降,CD44v3蛋白和CD44v6蛋白表达上升;TNF-α作用后细胞侵袭力提高(P＜0.001).结论:在人乳腺癌细胞株MCF-7中,TNF-α可能通过影响CD44各亚型mRNA和蛋白表达水平,进而促进肿瘤细胞的侵袭能力.     

LOX在乳腺癌中的表达及与MMP-2、MMP-9相关性的实验研究

目的 探讨赖氨酰氧化酶(LOX)在不同侵袭、转移潜能的乳腺癌细胞株的表达及LOX与MMP-2、MMP-9的关系.方法 以RT-PCR检测LOX mRNA在乳腺癌细胞株MDA-MB-231、MCF-7的表达水平.40只裸鼠随机分为2组,每组裸鼠的乳腺脂肪垫内分别接种上述不同的细胞,建立人乳腺癌原位移植瘤模型.6周后测定肿瘤体积,SP免疫组织化学法检测移植瘤中LOX、MMP-2、MMP-9的表达情况,并对数据进行统计学处理.结果 高侵袭、转移潜能的乳腺癌细胞后第6天均有肿瘤形成,至6周时MDA-MB-231组肿瘤体积为(758.84±241.08)mm3,MCF-7组为(210.36±101.06)mm3,差异有统计学意义(P＜0.01).LOX与MMP-2、MMP-9的表达呈正相关(P＜0.01).结论 乳腺癌细胞高侵袭、转移的潜能可能与LOX、MMP-2、MMP-9的高表达及其相互之间协同作用相关.     

Snail促进乳腺癌MCF-7细胞移植瘤对多柔比星的耐药及其机制

目的:探讨Snail在乳腺癌MCF-7细胞移植瘤对多柔比星耐药中的作用及其可能的机制。方法:构建Snail基因真核表达载体pcDNA3.1-Snail,转染至MCF-7细胞,筛选稳定表达Snail的MCF-7/Snail细胞,以转染空质粒pcDNA3.1的MCF-7细胞(MCF-7/pcDNA)为对照。构建小鼠MCF-7/Snail及MCF-7/pcDNA细胞移植瘤模型,注射多柔比星,观测移植瘤生长,计算抑瘤率。免疫组织化学方法检测移植瘤组织中Snail、多药耐药基因-1(multidrug resistance-1,MDR-1)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)的表达。结果:成功构建pcDNA3.1-Snail表达载体,转染MCF-7细胞后获得MCF-7/Snail和MCF-7/pcDNA细胞,并制备小鼠移植瘤。多柔比星治疗后,MCF-7/Snail细胞移植瘤的瘤重明显高于MCF-7/pcDNA细胞移植瘤[(1.413±0.674)g vs(1.257±0.576)g,P<0.05],多柔比星对MCF-7/Snail移植瘤抑瘤率明显低于MCF-7/pcDNA移植瘤(18.42%vs30.18%,P<0.05),MCF-7/Snail细胞移植瘤的组织中Snail、MDR-1、MMP-9的表达均显著高于MCF-7/pcDNA移植瘤(408.08±20.39vs67.67±16.56,363.50±26.56vs55.08±12.23,396.25±16.03vs56.92±7.35;均P<0.01),且Snail与MDR-1和MMP-9的表达均呈正相关(r1=0.89,P<0.01;r2=0.81,P<0.01)。结论:Snail促进乳腺癌MCF-7细胞移植瘤对多柔比星的耐药,其机制与增强MDR-1和MM9-9表达有关。     

膜型基质金属蛋白酶-1上调人乳腺癌细胞血管内皮生长因子的表达并诱导肿瘤血管新生

目的 研究膜型基质金属蛋白酶-1(MT1-MMP)在肿瘤血管新生过程中的作用,探讨其诱导肿瘤血管新生的作用途径.方法 应用基因转染方法 ,将MT1-MMP导入人乳腺癌细胞系MCF-7细胞;应用半定量逆转录聚合酶链反应(RT-PCR)和免疫荧光染色,比较转染前后肿瘤细胞血管内皮生长因子(VEGF)表达的变化;通过裸鼠异种移植瘤模型,检测MT1-MMP对肿瘤生长速度、肿瘤组织微血管密度(MVD)和VEGF表达的影响.结果 在MT1-MMP稳定转染后的MCF-7细胞中,VEGF189、VEGF165和VEGF121 mRNA表达水平显著上调(P＜0.001).免疫荧光检测结果 显示,MT1-MMP组的VEGF蛋白免疫荧光强度为93.8±10.3,明显强于MCF-7组(42.9±5.3)和pcDNA3.1组(41.0±5.4,P＜0.001).裸鼠异种移植瘤模型结果 显示,MTI-MMP能够加快肿瘤生长速度.肿瘤组织MVD检测结果 显示,MT1-MMP能够显著提高肿瘤组织的MVD(P＜0.05).免疫组织化学染色结果 显示,VEGF在MT1-MMP组呈强阳性表达.结论 MT1-MMP能够通过上调肿瘤细胞VEGF表达水平而有效诱导肿瘤血管新生.MT1-MMP的这一作用途径可能为临床抗肿瘤研究及抗肿瘤药物开发提供新思路.     

膜型基质金属蛋白酶-1在基质金属蛋白酶-2活化中的作用机制

目的:研究MMP-2的活化并探索其机制.方法:采用酶谱分析方法检测瘤细胞条件培养基中MMP-2在包被前后表达和活化的情况,用RT-PCR方法检测MT1-MMP mRNA的表达,观察MT1-MMP激活的MMP-2在细胞侵袭中的作用,Boyden小室膜侵袭实验检测细胞的侵袭能力.结果:条件培养基明胶酶谱分析结果显示仅在三维聚I型胶原包被组存在MMP-2的活性形式;培养于I型胶原组的人MCF-7细胞MT1-MMP mRNA表达量明显高于对照组,与对照组间差异显著(P<0.01).Boyden小室膜侵袭实验可见,用MT1-MMP的抗体处理组的细胞数明显少于未用MT1-MMP的抗体处理组,差异有统计学意义(P<0.01).结论:I型胶原成分可以通过上调MT1-MMP的水平来调控人乳腺癌MCF-7细胞MMP-2的活化,MT1-MMP激活的MMP-2可以增强人乳腺癌MCF-7细胞的侵袭能力.     

人参多糖注射液对人乳腺癌MCF-7细胞侵袭迁移能力的影响及机制研究

目的 探讨人参多糖注射液对人乳腺癌细胞株MCF-7侵袭迁移能力的影响。方法 以不同作用浓度(12.5μL/mL、25μL/mL、50μL/mL、100μL/mL)人参多糖注射液处理MCF-7细胞株,以PBS作为空白对照,分别采用Transwell小室侵袭实验、划痕实验及Western blot检测细胞侵袭能力、迁移能力及基质金属蛋白酶-2(MMP-2)和基质金属蛋白酶-9(MMP-9)表达。结果 人参多糖注射液对MCF-7细胞体外侵袭和迁移能力具有显著的抑制作用,并呈现剂量及时间依赖性。人参多糖注射液处理后,MCF-7细胞MMP-2蛋白表达及MMP-9蛋白表达比值显著降低,并呈现剂量及时间依赖性。结论 人参多糖注射液可显著抑制人乳腺癌细胞MCF-7侵袭能力和迁移能力,下调MMP-2及MMP-9蛋白表达是其可能的作用机制。     

MAG-1对人肺癌细胞转移能力的影响及其在24例肺癌组织中的表达

背景与目的 肺癌转移相关基因-1(Pulmonary cancer Metastasis Associated Gene-1,MAG-1)是利用抑制消减杂交技术获得的与肺癌转移相关的基因.此研究的目的在于探讨基因MAC-1对肺巨细胞癌细胞的转移相关生物学行为的影响及其在24例肺癌组织中的表达情况.方法 构建MAG-1的正反义表达载体,分别转染PLA801C和PLA801D,获得稳定表达相应序列的细胞株,观察稳定转染细胞的多种肿瘤转移相关能力的改变,并检测MAG-1对CD44、MMP-2等分子的影响,最后还检测TMAG-1在源于不同转移状况患者的肺癌标本中的表达情况.结果 MAG-1对细胞生长、细胞与胞外基质的粘附能力以及侵袭能力均有促进作用;并能促进细胞中CD44和MMP-2的表达;MAC-1 mRNA在有转移的肺癌中的阳性率(7/12)高于其在无转移的肺癌标本中的阳性率(2/12).结论 MAG-1具有增强肺癌细胞转移能力的功能,并且在转移性肺癌组织中其mRNA具有较高的阳性检出率,是可能的肺癌转移相关基因.     

MMP-9、CD44v6在骨肉瘤中的表达及其临床意义

目的 探讨骨肉瘤组织中MMP-9、CD44v6的表达及其临床意义。方法 应用免疫组化方法检测70例骨肉瘤、15例骨软骨瘤和15例正常骨组织中CD44v6和MMP-9的表达情况,分析其相关的临床病理因素,并进行回顾性随访。结果 在骨肉瘤组织中,MMP-9、CD44v6阳性表达率明显高于骨软骨瘤和正常骨组织;MMP-9阳性表达与骨肉瘤软组织侵袭及预后有一定关系;CD44v6的表达与MMP-9的表达呈正相关的关系。结论 CD44v6与MMP-9均可作为骨肿瘤恶性表型的辅助指标;MMP-9与骨肉瘤的侵袭、转移相关,可作为预测骨肉瘤转移潜能的指标。     

白藜芦醇对宫颈癌HeLa细胞基质金属蛋白酶及其组织抑制剂的影响

目的探讨白藜芦醇对宫颈癌侵袭和转移的影响及其初步作用机制。方法选用Transwell侵袭系统,观察白藜芦醇对宫颈癌细胞侵袭转移的影响;用明胶酶谱法、RT-PCR和Western blot法了解白藜芦醇对宫颈癌细胞MMP-2、MMP-9、TIMP-1、TIMP-2的活性、mRNA及蛋白表达的影响。结果白藜芦醇1、0.5mmol/L两组平均穿过的细胞数分别为9.20±1.924,10.20±2.049与空白对照组(39.80±2.387)相比,明显减少,P<0.05。同时,白藜芦醇能够明显降低宫颈癌细胞MMP-2、MMP-9的活性、mRNA及蛋白表达水平(P<0.05),上调TIMP-1、TIMP-2的活性(F=636.354,P<0.05,F=87.516,P<0.05)、mRNA(F=9.000,P<0.05,F=10.288,P<0.05)及蛋白表达水平(F=39.329,P<0.05,F=12.148,P<0.05),并使得MMP-2/TIMP-2、MMP-9/TIMP-1减小,P<0.05。结论白藜芦醇能有效抑制宫颈癌侵袭和转移。其作用机制可能与降低宫颈癌细胞运动能力、抑制MMP-2、MMP-9的活性、mRNA及蛋白表达水平,上调TIMP-1、TIMP-2的活性、mRNA及蛋白表达水平,并使得MMP-2/TIMP-2、MMP-9/TIMP-1减小,MMP-2/TIMP-2、MMP-9/TIMP-1的平衡能力相应提高有关。     

Construction of double suicide genes system controlled by MDR1 promoter with targeted expression in drug-resistant glioma cells

The multiple drug resistance protein (MDR1) is frequently overexpressed in human glioma. The aim of this study is to clone the MDR1 promoter from C6/ADR, construct the double suicide genes expressive vector controlled by MDR1 promoter, and explore its targeted expression in C6/ADR cells. MDR1 promoter from C6/ADR genomic DNA, which was linked with T vector, was amplified by using Polymerase chain reaction (PCR). After cut by NdeI and HindIII, MDR1 promoter was cloned into pcDNA3-TK (thymidine kinase) plasmid. The cytosine deaminase (CD) gene from pcDNA3-CD-TK plasmid was directly cloned into the above vector to construct pcDNA3-MDR1-promoter-CD-TK vector. Then this vector was transfected into C6 and C6/ADR cells respectively by liposome. After selection by G418, the tumor cell lines were stably established. Then these cell lines were examined through PCR and RT-PCR to respectively detect the integration and expression of TK and CD genes. The results showed the length and sequence of MDR1 promoter amplified by PCR were confirmed by DNA sequencing. The pcDNA3-MDR1-promoter-CD-TK expression vectors were constructed successfully. PCR indicated the double suicide genes were integrated into C6 and C6/ADR cells. RT-PCR reveled that CD and TK genes expressed in C6/ADR/CD-TK cells, whereas not in C6/CD-TK cells. In conclusions, construction of expressive vector containing double suicide genes controlled by MDR1 promoter with targeted expression in C6/ADR will provide a sound basis for targeted gene therapy for multidrug resistance (MDR) glioma.     

CD44 variant expression and estrogen receptor status in breast cancer

To understand the relationship between CD44 gene expressionand an established variable associated with aggressive behaviourin human breast cancer, we have studied apanel of 6 breast cell lines and 40breast tumors selected primarily on the basis ofestrogen receptor (ER) status. CD44s (standard form) mRNAwas assessed by semi-quantitative RT-PCR, and CD44 variantsincorporating exon v7 or v10 were studied byRT-PCR and Southern blot. While CD44 expression wasnot influenced by estrogen in ER+ve MCF-7 cells,CD44s expression was slightly higher (up to 2fold) in ER–ve cells but there was amarked decrease in the range of CD44 variantsincorporating exons v7 or v10. In microdissected tumors,the levels of CD44s showed no correlation withER status but the pattern of expression oflarger forms of CD44 incorporating variant exons v7and v10 was significantly different (p=0.005and p=0.015, respectively) between ER+ve andER–ve tumors, reflecting the pattern seen in thecell lines. These findings suggest that the profileof CD44 expression in breast cancer may reflectcellular differentiation as indicated by the ER phenotype.The influence of these differences in CD44 expressionon the increased metastatic potential of ER negativebreast cancer remains to be determined.     

microRNA-21对乳腺癌MCF-7/ADR细胞株多柔比星耐药性影响的研究

目的:探讨microRNA-21(miR-21)基因表达改变对乳腺癌细胞多柔比星化疗耐药的影响.方法:人工合成miR-21模拟序列或干扰序列,以脂质体为载体,转染乳腺癌细胞MCF-7及其多柔比星耐药细胞株MCF-7/ADR;应用荧光定量RT-PCR检测miR-21的表达;应用MTT法检测细胞转染前后对多柔比星的耐药性;应用流式细胞仪检测细胞凋亡;应用蛋白质印迹法检测PTEN、BAX及Bcl-2蛋白的表达.结果:MTT检测结果示,MCF-7及其耐药株MCF-7/ADR细胞多柔比星半数抑制浓度(IC50)分别为(0.28±0.03)和(17.5±0.12) μmol/L.miR-21表达上调,MCF-7细胞对多柔比星的IC50明显增高为(3.65±0.12) μmol/L;miR-21表达下调,MCF-7/ADR细胞对多柔比星的IC50明显降低为(7.53±0.11) μmol/L.流式细胞分析显示,miR-21下调后MCF-7/ADR细胞凋亡率明显增加.同时,细胞内PTEN、BAX蛋白表达水平增加,Bcl-2表达降低.结论:miR-21在乳腺癌化疗耐药中具有重要作用,抑制miR-21的表达可以逆转乳腺癌多柔比星耐药细胞株对多柔比星的耐药性.     

Matrilysin over-expression in MCF-7 cells enhances cellular invasiveness and pro-gelatinase activation

Matrilysin (MMP-7) is over-expressed in various cancers and is thought to play important roles in tumor invasion and metastasis. However, the function of MMP-7 in breast cancer remains unclear. We therefore examined the expression of the MMP-7 gene in breast cancer (MCF-7) cells and the effect of its over-expression on cellular invasion. We transfected human MMP-7 into MCF-7 cells and selected clones that stably over-expressed the MMP-7 gene. The in vitro invasiveness of MCF-7 cells was quantified by use of the Matrigel invasion assay. Expression of MMP-7 mRNA was analyzed by quantitative RT-PCR. MMP secretion and activation were detected by gelatin zymography. We found that MMP-7-expressing clones had significantly increased invasion (P < 0.001), with increased MMP-7 expression and gelatinase activation as compared to the vector controls. We conclude that MMP-7 over-expression correlates with breast cancer in vitro invasiveness and that MMP-7 may promote invasion by increasing the secretion and activation of proMMP-2 and proMMP-9.     

Sphk1基因对间充质干细胞诱导结肠癌RKO细胞增殖和迁移的影响

目的： 探讨鞘氨醇激酶1 （sphigosine kinase 1, SphK1）基因下调对间充质干细胞（mesenchymal stem cell, MSC）诱导的 结肠癌RKO细胞增殖和迁移的影响。 方法： 采用MSC条件培养液（MSC-CM）和对照培养液（Control-CM）分别干预RKO细胞, CCK-8法检测细胞的增殖能力,Transwell实验检测细胞的迁移能力,Western blotting法检测Ki-67抗原（Ki-67）、MMP-2/9、肿瘤干 细胞标志物CD44和CD133蛋白的表达。用慢病毒shRNA载体转染RKO细胞抑制SphK1的表达,观察抑制SphK1的表达对 MSC-CM诱导的RKO细胞增殖、迁移以及MMP-2/9、CD44和CD133蛋白表达的影响。 结果： MSC-CM可时间依赖性促进RKO 细胞的增殖(P<0.05),并明显增强细胞的迁移能力(P<0.01)和细胞中Ki-67、MMP-2/9、CD44和CD133蛋白的表达(均P<0.05或P< 0.01)。慢病毒shRNA转染明显抑制RKO细胞SphK1的表达,抑制SphK1的表达可显著抑制MSC-CM对RKO细胞增殖和迁移的 促进作用(均P<0.05或P<0.01),且明显抑制MSC-CM诱导的Ki-67、MMP-2/9、CD44和CD133蛋白的表达。 结论： MSC-CM可 促进RKO细胞的增殖和迁移,下调SphK1可通过抑制MMP-2/9、CD44和CD133的表达逆转MSC-CM诱导的细胞增殖和迁移。     

LRRK2在乳腺癌细胞增殖和耐药中的作用及其机制研究

目的:探讨LRRK2在乳腺癌组织中的表达及其对乳腺癌细胞增殖、凋亡及耐药的作用和分子机制.方法:采用实时荧光定量PCR(qRT-PCR)和Western blot检测了48例乳腺癌组织及其配对正常组织中LRRK2表达;并检测人正常乳腺上皮细胞MCF-10A、乳腺癌细胞株MCF-7、MDA-MB-231、BT-483及阿...     

siRNA逆转乳腺癌细胞系MCF-7/ADR耐药

背景与目的：肿瘤的多药耐药性常导致乳腺癌化疗失败,多约耐药基因1(multidrug resistance 1、mdr1)编码的P-糖蛋白(P-glycoprotein．P-gP)过度表达是重要的耐药机制。本研充拟探讨siRNA抑制耐药乳腺癌细胞系MCF-7／ADR mdr1基因表达的可行性。方法：选择耐阿毒素人乳腺癌细胞系MCF-7／ADR技其敏感细胞系MCF-7作为研究对象,将预先设计的siRNA包装入质粒载体,然后转化质粒刮大肠杆菌中,经过克隆、扩增、纯化后转染到MCF-7／ADR细胞中,潮霉素筛选,流式细胞仪检测P-gP的表达率,实时定量PCR俭测,mdr1基因的表达率,并对转染后的细胞作阿霉素耐药实验。结果：流式细胞仪榆测结果显示,MCF-7／ADR细胞经特异性siRNA作用后,P-gP的表达率由99．8％下降到12．3％：实时相对定量PCR检测结果显示．MCF-7／ADR细胞经特异性siRNA作用后其Ct值由25．22增加到30．64．阿霉素耐药实验显示,转染siRNA的MCF-7／ADR细胞IC50为0．51μmol／L,而术转染组的IC50为17．88μmol／L。结论：siRNA能引发人乳腺癌多耐药细胞系MCF-7／ADR内mdr1基因沉默,从而为siRNA作为一种可能的治疗手段提供了理论依据。     

钠氢交换蛋白抑制剂Cariporide对MCF-7/ADR细胞化疗敏感性影响机制研究

目的 肿瘤细胞膜内外pH值的改变对于肿瘤的侵袭、转移密切相关,通过细胞内外的H+/Na+交换维持细胞内环境的稳态,细胞的凋亡水平与化疗药物耐药的发生密切相关.本研究观察钠氢交换蛋白1(sodium hydrogen exchange 1,NHE-1)抑制剂 Cariporide(CP)对人乳腺癌细胞MCF-7/ADR增殖、凋亡和对多柔比星(adriamycin,ADR)敏感性影响,并探讨其相关作用机制.方法 以终浓度分别为3、6、9、12、60和100 μg/mL的CP处理MCF-7和MCF-7/ADR细胞48 h,以终浓度分别为1、5、50和100 μg/mL的ADR以及2种药物联用分别处理MCF-7/ADR细胞24、48 h,CCK8法检测其对细胞的增殖影响,Graphpad prism 5分别计算单用及药物联用时的IC50,CompuSyn软件计算2种药物的联用指数(CI);采用流式细胞术检测药物单用及联用后对细胞凋亡率的影响;RT-PCR法检测MDR-1、NF-κB等相关核转录因子的表达;蛋白质印迹法检测CD44、MDR-1、NF-κB p65、Caspase-3/9和Bcl-2的表达.结果 CP对乳腺癌细胞有增殖抑制作用,呈剂量及时间依赖性,CP与ADR联用可以明显降低ADR对MCF-7/ADR细胞的IC50值,其值由(82.45±5.86) μg/mL下降至(42.2±2.03) μg/mL,t=7.57,P<0.05.流式细胞术检测结果显示,对照组、单用ADR组、单用CP组、药物联用组细胞的凋亡率分别为(4.02±0.19)%、(6.34±0.39)%、(9.55±0.47)%和(15.12±0.65)%,F=666.2,P<0.001.荧光定量PCR结果表明,单用CP及CP联用ADR组MDR-1、NF-κB mRNA 表达均下降.蛋白质印迹法结果显示,单用CP及CP联用ADR耐药相关蛋白CD44、MDR-1表达下调,NF-κB p65表达下调,抑凋亡蛋白Bcl-2表达下降,凋亡相关蛋白cleaved Caspase-3和cleaved Caspase-9表达上调.结论 CP可以增加MCF-7/ADR细胞对ADR的敏感性,可能是通过下调耐药相关蛋白的表达,活化凋亡相关蛋白,诱导细胞凋亡,从而有效逆转肿瘤细胞的耐药.     

Expression of CD44 variant exons in acute myeloid leukemia is more common and more complex than that observed in normal blood, bone marrow or CD34+ cells.

CD44 is an adhesion molecule that is expressed on hematopoietic cells and has been implicated in the interactions between bone marrow stromal layers and hematopoietic progenitors. The expression of variant forms of CD44, particularly forms containing exon v6, have been associated with poor prognosis in a number of hematological malignancies. The expression of CD44 variants on normal bone marrow (BM), peripheral blood (PBMC) and CD34+ hematopoietic progenitors was compared with those expressed on blasts from 30 patients with acute myeloid leukemia (AML). Normal BM, PBMC and CD34+ progenitor cells were negative for all variants tested by flow cytometry. In contrast exon v3 was expressed on 13%, v4 on 67%, v5 on 19%, v6 on 7% and v7 on 65% of AML cases. RT-PCR and Southern blotting revealed the expression of exons v3, v6, v8, v9 and v10 in normal bone marrow and peripheral blood mononuclear cells and the expression of exons v3, v6, v8 and v10 in CD34+ progenitors. A more complex pattern of variant exon expression was observed in leukemic samples in comparison to normal hematopoietic cells. Sixty-two percent of AML cases expressed exon v3 and 70% exon v6. Exons v4 and v5 were not detected while exons v7, v8, v9 and v10 were detected in 21, 83, 71 and 92% of cases, respectively. In summary, our data demonstrate a striking increase in the complexity of CD44 variant expression in cells from patients with AML, along with surface expression of some variant CD44 proteins. Further analysis will be directed at how these alter the interaction of leukemic blasts with the bone marrow microenvironment and their diagnostic, prognostic and therapeutic potential.     

反义封闭MMP-9基因表达对胶质母细胞瘤细胞系增殖的影响

目的 探讨反义封闭胶质瘤细胞MMP-9基因表达对胶质瘤细胞增殖的影响。方法 利用基因重组的方法构建正义和反义MMP-9重组体;经脂质体介导,分别将pcDNA3.0空载质粒、正义重组体、反义重组体转染TJ905细胞;通过RT-PCR和Western blot检测转染细胞MMP-9的mRNA和蛋白表达水平;利用免疫组织化学法分析了转染细胞中MMP-9和Ki-67的表达。结果经限制性酶切鉴定和DNA测序分析,基因重组成功,且正义与反义重组体插入位点间的序列方向正好相反。与TJ905对照组、空载体组和正义对照组相比较,转染反义重组体后的TJ905细胞中MMP-9 mRNA和蛋白的表达水平明显下降（P<0.001）。转染空载体和正义重组体后,TJ905细胞内MMP-9 mRNA和蛋白的表达水平与未进行转染的TJ905细胞相比差异无统计学差异（P>0.05）。免疫组织化学结果显示反义封闭有效,MMP-9的表达下调,TJ905细胞增殖活性下降。结论 转染反义MMP-9重组体可以有效抑制胶质母细胞瘤细胞的MMP-9基因的表达,同时可以抑制肿瘤细胞的增殖。