结肠癌组织中CD44S和CD44V6基因蛋白的表达及意义

目的研究CD44S和CD44V6的表达与结肠癌临床病理特征之间的关系,以明确二者在结肠癌发展和预后中的作用。方法选取98例结肠癌组织做为实验组,采用免疫组织化学方法,检测组织中CD44S和CD44V6基因蛋白产物表达,与组织学分型、肠壁浸润深度、脉管有无浸润、淋巴结有无转移、预后等相关因素进行实验研究。结果 CD44S和CD44V6的表达与结肠癌组织类型无关,与癌组织浸润肠壁深度、脉管浸润、淋巴结转移、远处转移等密切相关。结论 CD44S和CD44V6异常表达可能参与了结肠癌的发展并可能影响患者的预后。     

E-cadherin和CD44V6在食管上皮癌变过程及癌组织中的表达

研究不同类型的食管上皮增生和癌组织的 E- cadherin (E- cad)和 CD44 V6的表达 ,并探讨其与食管癌发生和发展的关系。应用免疫组织化学 SABC法 ,观察 10例正常、 3例消化性溃疡、 2 5例单纯性增生、 15例不典型增生的食管粘膜上皮 ,5例食管原位癌与 5 4例浸润癌组织中的 E- cad和 CD44 V6蛋白的表达情况。结果显示正常食管鳞状上皮和高分化肿瘤细胞膜和细胞浆 E- cad和 CD44 V6染色 ,非典型增生、低分化肿瘤细胞两种蛋白抗体表达减弱或呈阴性。E- cad和 CD44 V6的表达与癌组织的组织学分级、类型和淋巴结转移有关 (P<0 .0 1,P<0 .0 5 ) ,与癌组织的浸润深度无关 (P>0 .0 5 )。提示E- cad和 CD44 V6表达减弱是癌组织低分化和高度恶性的生物学标志 ,但其与淋巴结转移的关系有待进一步研究     

CD44V6和MMP-2在甲状腺肿瘤中的表达及其临床意义

目的:研究黏附分子CD44V6和基质金属蛋白酶-2(MMP-2)在甲状腺癌中的表达、相互关系及其与甲状腺癌侵袭转移的相关性.方法:采用SP免疫组化法检测114例甲状腺肿瘤组织中CD44V6和MMP-2的表达.结果:CD44V6和MMP-2在35例甲状腺乳头状癌(Papillary Thyroid Carcinoma,PTC)中阳性表达率分别为70.6%和73.5%,在41例甲状腺滤泡癌(Follicular Thyroid Carcinomas,FTC)中阳性表达率分别为70.7%和75.6%,均高于甲状腺腺瘤和结节性甲状腺肿组织中的表达,差异具有统计学意义(P＜0.05).在甲状腺癌组织中MMP-2和CD44V6的表达具有显著相关性(r=0.4828,P＜0.001).且两者表达与甲状腺癌的临床分期及有、无淋巴结转移显著相关.结论:CD44V6和MMP-2的表达与甲状腺癌分化程度、浸润和转移关系密切.CD44V6和MMP-2检测对甲状腺癌的诊断、分化程度、转移趋势和预后评估具有重要参考价值,是甲状腺癌侵袭、转移和预后判断的分子标志物.     

胃癌及相应癌旁组织中VEGF、CD34、CD44v6的检测及临床意义

目的:探讨血管内皮生长因子(Vascular endothelial growth factor,VEGF)、CD34和CD44v6在胃癌及相应癌旁组织中的表达及其与临床病理意义.方法:应用免疫组化技术检测60例胃癌以及相应癌旁组织中VEGF、CD34和CD44v6的表达.结果:胃癌组织VEGF阳性率为71.67%(43/60)明显低于癌旁组织88.34%(53/60),两组间有显著性差异(P=0.022);VEGF阳性表达与胃癌病理分级、浸润深度、淋巴结转移和临床分期密切相关(P＜0.05).癌旁组织中微血管密度(MVD)明显高于癌组织MVD(P=0.000),有淋巴结转移癌组织中MVD高于无淋巴结转移者(P=0.043),并随浸润深度、临床分期MVD升高(P=0.046,P=0.000).癌旁组织中CD44v6阳性率为48.34%(29/60)低于癌组织的61.67%(37/60),两者无明显差别.CD44v6的阳性率随胃癌浸润的加深而升高,与淋巴结转移和TNM分期呈正相关.VEGF、CD34及CD44v6三指标间两两相关(P＜0.05).结论:VEGF、CD34和CD44v6三者联合检测有助于判断胃癌的浸润、转移及预后情况.     

CD44v6、MMP-9、VEGF在胃癌的表达及临床意义

目的:检测胃癌组织中CD44v6、MMP-9、VEGF表达情况及其与胃癌临床病理因素的关系,并探讨其表达与胃裸区侵犯的临床意义。方法:采用免疫组化方法测定60例胃癌组织CD44v6、MMP-9、VEGF表达情况,并结合患者的临床病理资料进行分析。结果:CD44v6、MMP-9、VEGF的表达与胃癌的TNM分期、浸润深度、淋巴结转移有关。胃裸区受侵组与未受侵组胃癌组织的CD44v6、MMP-9、VEGF的表达无明显差异。结论:CD44v6、MMP-9、VEGF的表达与胃癌的浸润转移密切相关,胃裸区是否受侵与胃癌组织的CD44v6、MMP-9、VEGF的表达无关,胃裸区这一解剖结构可能是胃癌预后较差的原因。     

CD44v6和PTEN在胃印戒细胞癌中的表达意义

目的:探讨CD44v6和PTEN在胃印戒细胞癌组织中的表达与临床病理特征及预后之间的关系.方法:应用免疫组织化学SP二步法,检测73例胃印戒细胞癌组织中CD44v6及PTEN的表达,分析CD44v6、PTEN与胃印戒细胞癌浸润深度、淋巴结转移、器官转移、临床分期和三年生存率的关系.结果:73例胃印戒细胞癌组织中CD44v6阳性率为78.1%(57/73),PTEN阳性表达率为34.2%(25/73),PTEN表达与器官转移、临床分期有差异(P＜0.05),CD44v6、PTEN表达均与胃印戒细胞癌浸润深度、淋巴结转移有差异(P＜0.05).两者之间Spearman等级表达呈负相关(r=-0.214,P＜0.05);Kaplan-Meier生存分析显示PTEN阴性组三年生存率16.1%显著低于PTEN阳性组66.9%(P＜0.01).结论:进行CD44v6和PTEN免疫组织化学检测对评估胃印戒细胞癌的预后具有一定意义.     

胃癌中CD44v6 表达及与微血管密度和生物学行为的关系

目的:探讨CD44v6在胃癌中的表达及其与微血管密度(microvessel density,MVD)和生物学行为的关系。方法:采用免疫组化法检测80例胃癌组织CD44v6、CD34的表达,以CD34标记肿瘤微血管,并在显微镜下计数微血管密度(MVD)。结果:CD44v6在胃癌组织中的表达与肿瘤浸润深度、临床分期、淋巴结转移相关(P<0.05),CD44v6强阳性表达组中MVD明显高于CD44v6阴性表达组(P<0.05)。结论:CD44v6的表达和MVD计数是反映胃癌生物学特性的良好的指标,对判断胃癌的浸润转移具有一定的临床意义。     

胃癌CD44v6 mRNA及其蛋白表达与临床病理特征的关系

目的探讨细胞粘附分子CD44v6 mRNA及其蛋白表达与胃癌临床病理学行为和患者预后的关系. 方法应用高敏感性催化信号放大系统(catalyzed signal amplification,CSA)原位杂交和免疫组化技术,对17例早期胃癌、21例中期胃癌和57例晚期胃癌组织进行CD44v6 mRNA及其蛋白检测,并结合肿瘤的病理学行为和临床随访资料进行分析.结果在胃癌中,CD44v6 mRNA及其蛋白的表达阳性率分别为85.3%和82.1%.CD44v6 mRNA及其蛋白表达阳性率在晚期胃癌明显高于早、中期胃癌(P<0.05).CD44v6 mRNA表达与蛋白表达水平具有一致性,均与胃癌浆膜浸润,淋巴结转移和患者预后呈正相关(P<0.05).结论 CD44v6 mRNA及其蛋白异常表达与胃癌的临床病理生物学行为密切相关,特别是与胃癌细胞的转移潜能和胃癌患者的不良预后密切相关.CD44v6蛋白水平的表达可以间接反映其mRNA转录水平,并可作为预测胃癌转移潜能和患者预后的一个新的生物学指标.     

大肠癌及癌旁粘膜中CD_(44)、nm23-H_1的表达及其临床病理意义

探讨 CD44 、nm2 3- H1 的表达与大肠癌侵袭及转移的关系。应用免疫组化 SABC法检测 5 7例大肠癌组织及相应的癌旁粘膜、正常粘膜组织中 CD44 v6 、 CD44 S、 nm 2 3- H1 的表达 ,并分别比较其与大肠癌侵袭及淋巴结转移的关系。结果显示大肠癌组织 CD44 v6 的阳性率 (70 .18% )显著高于癌旁粘膜 (阳性率为 12 .0 2 % )及正常粘膜 (阳性率为 0 ) (P<0 .0 5 ) ;大肠癌组织 CD44 S和 nm2 3- H1 的阳性率 (分别为 42 .11%和 5 4.39% )显著低于癌旁粘膜 (分别为 89.47%和 91.2 3% )及正常粘膜(分别为 10 0 %和 94.74% ) (P<0 .0 5 )。CD44 v6 、nm2 3- H1 的表达与大肠癌浸润深度及淋巴结转移有相关性 (P<0 .0 5 ) ,与大肠癌分化程度无关 (P>0 .0 5 )。CD44 v6 与 nm2 3- H1 蛋白表达无明显相关性 (rs=- 0 .117,P>0 .0 5 )。结果表明 CD44 、nm2 3-H1 可作为大肠癌侵袭与淋巴结转移的重要标志     

双歧杆菌脂磷壁酸对结肠癌细胞CD44v6和MMP-2表达的影响

目的研究双歧杆菌脂磷壁酸(LTA)对结肠癌细胞中CD44v6与基质金属蛋白酶2(MMP-2)表达的影响,探讨其在抑制结肠癌转移中的作用。方法结肠癌LoVo细胞及HT-29细胞用含50 mg/L双歧杆菌LTA的培养液培养24 h后,RT-PCR和免疫细胞化学染色检测CD44v6和MMP-2在结肠癌细胞中的表达变化。结果结肠癌LoVo细胞及HT-29细胞中CD44v6和MMP-2的mRNA和蛋白质均呈高表达,经双歧杆菌LTA处理后,其表达均明显下降,与对照组比较,差异有非常显著性(P0.01)。结论双歧杆菌LTA可能通过下调CD44v6和MMP-2的表达来抑制结肠癌的转移。     

CD44s and CD44v6 expression in head and neck epithelia

Background

CD44 splice variants are long-known as being associated with cell transformation. Recently, the standard form of CD44 (CD44s) was shown to be part of the signature of cancer stem cells (CSCs) in colon, breast, and in head and neck squamous cell carcinomas (HNSCC). This is somewhat in contradiction to previous reports on the expression of CD44s in HNSCC. The aim of the present study was to clarify the actual pattern of CD44 expression in head and neck epithelia.

Methods

Expression of CD44s and CD44v6 was analysed by immunohistochemistry with specific antibodies in primary head and neck tissues. Scoring of all specimens followed a two-parameters system, which implemented percentages of positive cells and staining intensities from − to +++ (score = %×intensity; resulting max. score 300). In addition, cell surface expression of CD44s and CD44v6 was assessed in lymphocytes and HNSCC.

Results

In normal epithelia CD44s and CD44v6 were expressed in 60–95% and 50–80% of cells and yielded mean scores with a standard error of a mean (SEM) of 249.5±14.5 and 198±11.13, respectively. In oral leukoplakia and in moderately differentiated carcinomas CD44s and CD44v6 levels were slightly increased (278.9±7.16 and 242±11.7; 291.8±5.88 and 287.3±6.88). Carcinomas in situ displayed unchanged levels of both proteins whereas poorly differentiated carcinomas consistently expressed diminished CD44s and CD44v6 levels. Lymphocytes and HNSCC lines strongly expressed CD44s but not CD44v6.

Conclusion

CD44s and CD44v6 expression does not distinguish normal from benign or malignant epithelia of the head and neck. CD44s and CD44v6 were abundantly present in the great majority of cells in head and neck tissues, including carcinomas. Hence, the value of CD44s as a marker for the definition of a small subset of cells (i.e. less than 10%) representing head and neck cancer stem cells may need revision.     

CD44与肿瘤转移

透明质酸受体CD44是一类重要的粘附分子,与肿瘤转移密切相关,。早期认为CD44可促进肿瘤细胞的转移,但近来发现CD44与肿瘤志移之间的关系十分复杂,与CD44的分子类型及肿瘤组织类型皆有关。因此,尚需深入了解CD44在肿瘤转移过程中的分子机制,目前的研究发现CD44可能影响了肿瘤细胞的粘附,运动和胞外基质的降解等过程,临床上CD44有可能成为新的诊断指标和治疗靶点。     

Intracellular Domain Fragment of CD44 Alters CD44 Function in Chondrocytes

The hyaluronan receptor CD44 undergoes sequential proteolytic cleavage at the cell surface. The initial cleavage of the CD44 extracellular domain is followed by a second intramembranous cleavage of the residual CD44 fragment, liberating the C-terminal cytoplasmic tail of CD44. In this study conditions that promote CD44 cleavage resulted in a diminished capacity to assemble and retain pericellular matrices even though sufficient non-degraded full-length CD44 remained. Using stable and transient overexpression of the cytoplasmic domain of CD44, we determined that the intracellular domain interfered with anchoring of the full-length CD44 to the cytoskeleton and disrupted the ability of the cells to bind hyaluronan and assemble a pericellular matrix. Co-immunoprecipitation assays were used to determine whether the mechanism of this interference was due to competition with actin adaptor proteins. CD44 of control chondrocytes was found to interact and co-immunoprecipitate with both the 65- and 130-kDa isoforms of ankyrin-3. Moreover, this interaction with ankyrin-3 proteins was diminished in cells overexpressing the CD44 intracellular domain. Mutating the putative ankyrin binding site of the transiently transfected CD44 intracellular domain diminished the inhibitory effects of this protein on matrix retention. Although CD44 in other cells types has been shown to interact with members of the ezrin/radixin/moesin (ERM) family of adaptor proteins, only modest interactions between CD44 and moesin could be demonstrated in chondrocytes. The data suggest that release of the CD44 intracellular domain into the cytoplasm of cells such as chondrocytes exerts a competitive or dominant-negative effect on the function of full-length CD44.     

Engagement of CD44 promotes Rac activation and CD44 cleavage during tumor cell migration

CD44 is a major cell surface adhesion molecule for hyaluronan, a component of the extracellular matrix, and is implicated in tumor metastasis and invasion. We reported previously that hyaluronan oligosaccharides induce CD44 cleavage from tumor cells. Here we show that engagement of CD44 promotes CD44 cleavage and tumor cell migration, both of which were suppressed by a metalloproteinase inhibitor KB-R7785 and tissue inhibitor of metalloproteinases-1 (TIMP-1) but not by TIMP-2. We also present evidence that blockade of metalloproteinase-disintegrin ADAM10 (a disintegrin and metalloproteinase 10) by RNA interference suppresses CD44 cleavage induced by its ligation. Engagement of CD44 concurrently induced activation of the small GTPase Rac1 and led to drastic changes in cell morphology and actin cytoskeleton with redistribution of CD44 to newly generated membrane ruffling areas. A fluorescence resonance energy transfer approach to visualize GTP-bound Rac1 in living cells revealed the localization of the active Rac1 in the leading edge of the membrane ruffling areas upon ligation of CD44. Taken together, our results indicate that the cleavage of CD44 catalyzed by ADAM10 is augmented by the intracellular signaling elicited by engagement of CD44, through Rac-mediated cytoskeletal rearrangement, and suggest that CD44 cleavage contributes to the migration and invasion of tumor cells.     

E-cadherin negatively regulates CD44-hyaluronan interaction and CD44-mediated tumor invasion and branching morphogenesis

CD44 is a principal cell-surface receptor for hyaluronan (HA). Up-regulation of CD44 is often associated with morphogenesis and tumor invasion. On the contrary, reduction of cell-cell adhesion due to down-regulation of E-cadherin is associated with the invasive and metastatic phenotype of carcinomas. In our current study, we investigated the functional relationship between CD44 and E-cadherin. We established an inverse correlation between CD44 and E-cadherin indicating that the cells expressing higher levels of E-cadherin display weaker binding affinity between CD44 and HA. By using TA3 murine mammary carcinoma (TA3) cells, which display CD44-dependent HA binding, branching morphogenesis, and invasion, we demonstrated an inverse functional relationship between CD44 and E-cadherin by transfecting exogenous E-cadherin into the cells. Our results showed that increased expression of E-cadherin in TA3 cells, but not ICAM-1, weakens the binding between CD44 and HA and blocks spreading of the cells on HA substratum and CD44-mediated branching morphogenesis and tumor cell invasion. The results reported here demonstrated for the first time that E-cadherin negatively regulated CD44-HA interaction and CD44 function and suggested that balanced function of CD44 and E-cadherin may be essential for normal epithelial cell functions, and imbalanced up-regulation of CD44 function and/or down-regulation of E-cadherin function likely contributes to tumor progression.     

CD44 in inflammation and metastasis

CD44 is a major cell surface receptor for the glycosaminoglycan, hyaluronan (HA). CD44 binds HA specifically, although certain chondroitin-sulfate containing proteoglycans may also be recognized. CD44 binding of HA is regulated by the cells in which it is expressed. Thus, CD44 expression alone does not correlate with HA binding activity. CD44 is subject to a wide array of post-translational carbohydrate modifications, including N-linked, O-linked and glycosaminoglycan side chain additions. These modifications, which differ in different cell types and cell activation states, can have profound effects on HA binding function and are the main mechanism of regulating CD44 function that has been described to date. Some glycosaminoglycan modifications also affect ligand binding specificity, allowing CD44 to interact with proteins of the extracellular matrix, such as fibronectin and collagen, and to sequester heparin binding growth factors. It is not yet established whether the HA binding function of CD44 is responsible for its proposed involvement in inflammation. It has been shown, however, that CD44/HA interactions can mediate leukocyte rolling on endothelial and tissue substrates and that CD44-mediated recognition of HA can contribute to leukocyte activation. Changes in CD44 expression (mainly up-regulation, occasionally down-regulation, and frequently alteration in the pattern of isoforms expressed) are associated with a wide variety of cancers and the degree to which they spread; however, in other cancers, the CD44 pattern remains unchanged. Increased expression of CD44 is associated with increased binding to HA and increased metastatic potential in some experimental tumor systems; however, in other systems increased HA binding and metastatic potential are not correlated. CD44 may contribute to malignancy through changes in the regulation of HA recognition, the recognition of new ligands and/or other new biological functions of CD44 that remain to be discovered. Abbreviations: aa, amino acid(s); CS, chondroitin sulfate; CSPG, chondroitin sulfate containing proteoglycan; CD44H, ‘hematopoietic’, also called ‘standard’, isoform of CD44 which contains none of the alternatively spliced variant exons; CD44-Rg, CD44 receptor globulin, a secreted chimaeric protein composed of the external domain of the adhesion receptor CD44 and the hinge, CH2 and CH3 regions of human immunoglobulin-G heavy chain; ECM, extracellular matrix; GAG, glycosaminoglycan; HA, hyaluronan; HS, heparan sulfate; KS, keratan sulfate; PB, peripheral blood; PBL, peripheral blood lymphocytes This revised version was published online in November 2006 with corrections to the Cover Date.