CD44v6和E-cadherin表达与结直肠癌浸润转移关系

目的　探讨CD44v6和E cadherin(E cad)蛋白表达与结直肠癌浸润转移的相关性。方法　应用免疫组织化学技术 ,检测 90例结直肠癌组织中CD44v6和E cad蛋白表达。结果　 90例结直肠癌中CD44v6和E cad蛋白阳性表达率分别为75 6 %和 46 7%。CD44v6高表达及E cad低表达与结直肠癌Dukes分期、浆膜浸润、淋巴结转移、肝脏转移均呈正相关 (P <0 0 5 )。结直肠癌中CD44v6表达与E cad表达呈负相关 (r =- 0 4 3,P <0 0 0 5 )。结论　CD44v6和E cad表达与结直肠癌浸润转移密切相关。检测CD44v6和E cad蛋白表达可作为判断结直肠癌预后的客观指标。     

CD44 and its partners in metastasis

The establishment of metastasis requires that tumor cells acquire new adhesion and migration properties to emigrate from primary sites and colonize distant organs. CD44 is a cell membrane protein often overexpressed on tumor cells and, being both a cell–cell and cell–extracellular matrix adhesion protein, is well positioned to contribute to this process. Furthermore the interaction of CD44 with other cellular proteins involved in motogenesis and proteolysis is a determinant factor in cell migration and invasion. This review summarizes current knowledge on the role of CD44 in metastasis, as well as the challenges on understanding how this process operates. This revised version was published online in July 2006 with corrections to the Cover Date.     

Involvement of CD44 variant isoforms in hyaluronate adhesion by human activated T cells

The standard, 85–95-kDa form of the hyaluronic acid (HA) receptor CD44 and a number of CD44 mRNA splice variants play important roles in immune responses and tumor metastasis. Variants carrying exon 6 (v6), or 9 (v9) products are transiently expressed on activated human T cells. Here, modulation experiments with specific monoclonal antibodies (mAb) indicate that v6 and v9 are expressed independently on distinct sets of CD44 molecules, and that their combined expression is necessary for HA adhesion. Moreover, the finding that mAb-mediated cross-linking of v6 and v9 promoted cytosolic free Ca²⁺ mobilization and co-stimulated CD3-triggered T cell proliferation indicates that v6 and v9 possess signaling and effector function activation ability. Finally, HA-mediated signaling appears to be required for variant-dependent adhesion to HA. The observation that soluble HA promoted cytosolic free Ca²⁺ mobilization indicates that HA-induced Ca²⁺ mobilization can occur during T cell-HA interaction. Since Ca²⁺ mobilization was inhibited by pretreatment of cells with an anti-CD44 mAb directed against the HA-binding domain of CD44, CD44 receptors appear to be involved in HA-mediated signal transduction. The requirement of cytosolic free Ca²⁺ for adhesion is shown by the fact that ionomycin (a Ca²⁺ ionophore) stimulated, and EGTA (a Ca²⁺ chelator), inhibited HA adhesion. In addition, cytoskeletal functional activation is required for cell adhesion to HA, since drugs that block actin polymerization, such as cytochalasin B, or actomyosin contraction, such as the calmodulin antagonist W-7, inhibited cell adhesion to HA. As this adhesion is also ADP ribosylation-sensitive, it may involve a GTP-dependent function of CD44v, i.e. ankyrin binding. Our data indicate that there is a functional hierarchy among the CD44 molecules expressed on human peripheral blood T cells and that the splice variants, as compared to the standard form, exhibit a greater HA binding ability which involves CD44-mediated signaling and effector function activation.     

The CD44 variant isoforms CD44v6 and CD44v7 are expressed by distinct leukocyte subpopulations and exert non-overlapping functional activities

We have described recently that anti-CD44s, anti-CD44v6 and anti-CD44v7 interfere with delayed-type hypersensitivity (DTH) reactions. Yet, TNBS-induced colitis can be cured only by anti-CD44v7. To clarify the mechanisms underlying the divergent functional activities of CD44v6 and CD44v7 we explored their contribution to lymphocyte activation in vivo and in vitro. CD44v6 and CD44v7 are distinctly expressed on subpopulations of activated lymphocytes. Expression of CD44v6 is mainly restricted to T cell blasts. CD44v7 has been detected on CD4(+) cells, B cells and monocytes. Mitogenic and antigenic stimulation of lymphocytes in vitro was impaired in the presence of anti-CD44v6 and anti-CD44v7. Accordingly, anti-CD44v6 and anti-CD44v7 mitigated the DTH reaction in 2,4-dinitro-1-fluorobenzene-sensitized and challenged mice. However, the seemingly similar effects of CD44v6- and CD44v7-specific antibodies resulted from different activities. Anti-CD44v6 treatment led to a down-regulation of IL-2 and IFN-gamma production predominantly by CD8(+) cells. In anti-CD44v7-treated mice expression of IL-12 was decreased. Elevated levels of IL-10 accompanied this reduction. The latter resulted from an anti-CD44v7-mediated blockade of interactions between CD4(+) cells and monocytes as well as an active triggering of B cells. Thus, anti-CD44v6 and anti-CD44v7 interfere with lymphocyte activation at very specific points. CD44v6 functions predominantly at the T cell level. CD44v7 influences production of proinflammatory cytokines by B cells as well as an interaction between CD4(+) cells and antigen-presenting cells. As CD44 isoforms do not differ in their intracytoplasmatic tail, the distinct activities must result from expression on different leukocyte subsets and interactions with distinct ligands.     

CD44表达与乳腺癌淋巴结转移及预后相关因素的关系

目的：探讨ＣＤ４４表达与乳腺癌淋巴结转移与预后的关系。方法：采用ＬＳＡＢ法对７６例乳腺癌伴淋巴结转移和无转移组ＣＤ４４表达进行了免疫组化检测,并结合临床资料、增殖细胞核抗原（ＰＣＮＡ）、雌激素受体（ＥＲ）表达情况进行综合分析。结果：ＣＤ４４阳性率在乳腺癌伴淋巴结转移组为７０６％,无转移组为４５２％,两组间存在显著性差异（Ｐ＜００５）,随着组织学分级的增高ＣＤ４４表达呈递增趋势,Ⅰ级与Ⅱ、Ⅲ级间阳性率差异存在显著性（Ｐ＜００５）;ＣＤ４４与ＰＣＮＡ表达存在平行关系,与ＥＲ表达呈负相关趋势。结论：ＣＤ４４表达与乳腺癌淋巴结转移及预后有关,是乳腺癌患者预后判定有价值的生物学指标     

CD44 exon 6 expression as a possible early prognostic factor in primary node negative breast carcinoma

Breast cancer is the most common female malignancy affecting approximately one woman in eight. Many attempts have been made to define markers which may have potential clinical applications in diagnosis as well as therapy. New isoforms of CD44 with alternative spliced exons have recently been described. We studied the expression of CD44 exon 6 using a semi-quantitative RT-PCR reaction on a panel of 25 normal breast specimens, 10 mammary fibroadenomas, eight cystic samples and 52 primary breast tumors. Significant correlation was found between CD44 exon 6 expression and the overall survival of the N-M-population,P = 0.032, (logrank test by Mantel's method). The same result was also observed for the disease-free survival,P = 0.000002 (logrank test by Mantel's method). CD44 exon 6 expression, as detected by our RT-PCR-based method, might be a useful prognostic indicator of metastasis in breast cancer. However, these preliminary results need to be confirmed by later retrospective and prospective studies on a larger number of patients.     

CD44v6在胃癌中表达及其临床意义

目的：探讨ＣＤ４４Ｖ６与胃癌发生及胃癌生物学行为的关系。方法：应用免疫组化Ｓ－Ｐ方法研究１０例胃粘膜肠化及４６例胃癌的ＣＤ４４Ｖ６表达。结果：胃粘膜肠化及胃癌阳性率分别为１０％和６３％，淋巴结转移组阳性率（７５％）明显高于非转移组（４５％，Ｐ＜０．０５），且ＣＤ４４Ｖ６表达与Ｌａｕｒｅｎ分型相关。结论：ＣＤ４４Ｖ６分子参与肿瘤发生、发展     

Expression of standard CD44 in human colorectal carcinoma: Association with prognosis

The aim of the present study was to evaluate the expression of standard CD44 (CD44s) in colorectal cancer (CRC), its relationship with clinicopathological characteristics, and its potential prognostic significance. CD44s levels were measured on immunohistochemistry in tumors and surrounding normal mucosa from 74 patients with primary colorectal carcinomas. The patients were followed for a median period of 37 months. Expression of CD44s in primary tumor and surrounding normal mucosa tissues was demonstrated in 100% (74/74) and 37.9% (28/74), respectively. The expression of CD44s in tumors was significantly associated with the depth of invasion ( P  = 0.034) and lymph node involvement ( P  = 0.031). A significant difference was observed between the overall survival and level of tumor CD44s expression, especially for stage IV carcinoma ( P  = 0.038). Multivariate analysis indicated that TNM stage ( P  = 0.020) and tumor CD44s expression ( P  = 0.008) were independent predictors of overall survival in adenocarcinomas. CD44s overexpression may be an independent unfavorable prognostic factor for overall survival in advanced CRC, especially stage IV disease. Further investigation, however, is necessary to assess the biological roles of CD44 in CRC, and validate their possible value as novel therapeutic targets.     

Establishment of fluorescent lung carcinoma metastasis model and its real-time microscopic detection in SCID mice

Lung cancer is the most prevalent malignant tumor in the world. Metastasis of the disease causes death in lung cancer patients. Recent study has shown that multiple cascades of gene defects occur in lung cancer. In this report, we established a novel H1299/EGFP tumor model to determine whether H1299 transfected with the enhanced green fluorescent protein (EGFP) gene in vitro and xenotransplanted into SCID mouse lung would permit the detection of lung cancer micro-metastasis in vivo. We demonstrated that EGFP-transduced H1299 cells maintained stable high-level EGFP expressions during their growth in vivo. EGFP fluorescence clearly demarcated the primary seeding place and readily allowed for the visualization of distant micrometastasis and local invasion at the single-cell level. Small metastatic and locally invasive foci, including those immediately adjacent to the tumor's leading invasive edge, were almost undetectable by routine hematoxylin and eosin staining and immunohistochemistry. The GFP tagged lung cancer model is superior for the detection and study of physiologically relevant patterns of lung cancer invasion and metastasis in vivo. This revised version was published online in July 2006 with corrections to the Cover Date.     

应用流式细胞术对胃癌组织中CD44测定分析

目的:探讨CD44蛋白与胃癌细胞的关系.方法:应用流式细胞术测定胃癌组织CD44阳性细胞率和平均荧光强度.结果:在胃癌组织中,CD44细胞的阳性率为93.46±3.13％,明显高于其在正常组织的比率21.27±9.59％(P＜0.01);胃癌组织中CD44蛋白阳性细胞平均荧光强度为175.58±49.21,和正常组织细胞CD44蛋白阳性细胞的141.02±113.44无差别(P＞0.05).结论:胃癌组织中,CD44蛋白增多表明其在胃癌的发生、发展和转移中可能发挥重要作用.     

CD44s和CD44v6在宫颈鳞癌中表达及其临床意义

目的：探讨宫颈鳞癌中CD44s和CD44v6的表达及其与临床病理资料的关系。方法：应用免疫组化EnVision两步法对31例宫颈鳞标本中CD44s和CD44v6蛋白表达并进行分析。结果：肿瘤原发灶中CD44s阳性表达率为61．3％（19／31）。CD44v6阳性表达率为93．5％（29／31）,CD44v6阳性率高于CD44s,CD44s阳性表达与临床分期,病理分级和分类无关（P＞0．05）,CD44v6阳性表达与肿瘤细胞分化程度无关,但与浸润程度及分期有关（P＜0．05）,结论：CD44v6基因蛋白与宫颈鳞癌的侵袭,转移相关,可作为预测肿瘤进展和预后的一种有用指标。     

CD44基因拼接体、p53基因突变和染色体倍性与大肠癌转移之间关系的机理研究

目的:探讨大肠癌CD44v6表达、p53基因突变和染色体倍性与大肠癌转移之间的关系和作用机理.方法:流式细胞仪测定大肠癌细胞倍性及其在细胞周期各相中的分布;RT-PCR方法及特异探针D3对大肠癌细胞进行Southern Blot,并对杂交条带进行辉度扫描;银染PCR单链构象多态性(SSCP)技术检测大肠癌细胞p53基因突变.结果:正常对照、良性腺瘤、肿瘤未转移和肿瘤转移组其CD44v6阳性率和p53基因突变率呈逐渐上升趋势,CD44v6辉度扫描表明肿瘤未转移组(2 317.26±198.73)和转移组(10024.16±855.40)相比较,表达量有显著差异(P＜0.02);CD44v6阳性和阴性两组中G2M期细胞均值分别占6.24%和5.48%(P＞0.05),异倍体细胞分别为62.16%和60.00%(P＞0.5);而p53基因突变和未突变两组中G2M细胞占10.33%和4.01%(P＜0.05),异倍体细胞分别为85.20%和30.00%(P＜0.005);肿瘤异倍体细胞转移率显著高于二倍体细胞.结论:CD44v6的表达与转移高度相关,CD44v6和p53基因突变与肿瘤转移关系可能涉及不同的作用机理.CD44v6与p53基因突变相比较而言,CD44v6不失为一个更好的肿瘤转移标记.     

结直肠癌CD44V6、E-cadherin和VEGF的表达及其意义

目的：探讨结直肠癌CD44V6、E-cadherin和VEGF的表达及其临床意义。方法：应用免疫组化S－P法检测46例结直肠癌CD44V6、E-cadherin和VEGF的表达，并分析其与结直肠癌临床病理特征的关系。同时检测了23例淋巴结转移灶CD44V6、E-cadherin和VEGF的表达。结果：结直肠癌组织中CD44V6、E-cadherin和VEGF阳性表达率分别为50．0％、56．5％、和50．0％；原发灶CCD4V6和VEGF阳性表达率低于淋巴结转移灶（60．9％和56．％），而原发灶E-cadherin阳性表达率则高于淋巴结转移灶（43．5％）。结直肠癌CDV46和VEGF阳性表达与淋巴结转移，局部浸润深度和Dukes分期等有关。E-cadherin阳性表达与结直肠癌临床病理特征无关。结论：CD44V6和VEGF是结直肠癌发生与发展重要的促进因子，其过度表达与结直肠癌浸润转移，病理分期有关，可作为预测结直肠癌预后的生物学指标之一。     

Ezrin和CD44v6在胃癌中的表达及其临床意义

目的 探讨胃癌组织中Ezrin和CD44v6的表达及其临床病理意义.方法 应用免疫组织化学(SP法)检测73例胃腺癌患者组织标本、15例胃不典型增生组织及12例癌旁胃黏膜组织中Ezrin和CD44v6的表达情况.结果 (1)Ezrin 在正常胃黏膜组、胃不典型增生组和胃癌组中的阳性表达率分别为41.7%、53.3%和83.6%.CD44v6在正常胃黏膜组、胃不典型增生组和胃癌组中的阳性表达率分别为25%、40%和82.2%.(2)Ezrin和CD44v6的表达与淋巴结转移密切相关,有淋巴结转移组Ezrin与CD44v6的阳性率均明显高于无淋巴结转移组(P<0.05);在Ezrin和CD44v6同时表达组中,淋巴结转移率为63%(34/54例)高于两者均为阴性组(1/6例,16.7%)(P＜0.05).结论 联合检测Ezrin和CD44v6的表达有助于预测胃癌的恶性程度和转移潜能.     

ADAM-17 associated with CD44 cleavage and metastasis in oral squamous cell carcinoma

ADAM-17 (a disintegrin and metalloproteinase 17) is a membrane-anchored protein, which can cleave the ectodomain in a variety of transmembrane proteins. In the in vitro experiments with tumor cells, ADAM-17 is reported to cleave CD44, an adhesion molecule that interacts with hyaluronic acid, to promote tumor cell migration. In the present study, we examined ADAM-17 expression and CD44 cleavage in specimens from 50 patients diagnosed to have oral squamous cell carcinoma (SCC). Each specimen was divided into two pieces, one was studied by immunohistochemistry and the other was subjected to a Western blot. By coordinating the results of both analyses, ADAM-17 expression was evaluated to be high in 23 cases (46%). When CD44 cleavage was also studied by immunohistochemical staining as well as with Western blotting, CD44 cleavage was judged to be positive in 29 cases (58%). When the ADAM-17 expression level was compared with the CD44 cleavage state, most of the cases expressing high levels of ADAM-17 (87%) showed positive CD44 cleavage. The level of ADAM-17 expression was significantly correlated to the nodal metastasis and local recurrence in oral SCC. Our findings suggest that ADAM-17 is involved in CD44 cleavage and contributes to tumor progression in oral SCC.     

Membrane protein glycosylation and CD44 content in the adhesion of human ovarian cancer cells to hyaluronan

The adhesion of tumour cells to the hyaluronan (HA) pericellular coat of mesothelial cells is an important step in the peritoneal spread of ovarian cancer. Previously, we have shown that the cell surface molecule CD44 is involved in this process. Paradoxically, the degree of adhesion does not appear to be related to the amount of CD44 expressed. In order to explain this observation we have examined the in vitro adhesion to HA of four high CD44-expressing ovarian cancer lines in relation to their CD44 spliced variant content and the CD44 glycosylation. Adhesion was measured in multiwell plates coated with different concentrations of HA in order to determine both the avidity and the maximum adhesion. Two lines had high adhesion and two lines had low adhesion. The avidity for HA was different for each line, but in all cases this could be totally blocked by treatment with an anti-CD44 antibody. The standard form of CD44 was the major species detected by RT/PCR in all lines and spliced variants were present in low amounts. Neuraminidase treatment increased the adhesion of the ‘low-adhesion’ lines at all HA coating concentrations; but only substantially increased the adhesion of the ‘high-adhesion’ lines at the lower HA coating concentrations. Tunicamycin treatment decreased the adhesion of the ‘high-adhesion lines’ at all HA coating concentrations and only substantially decreased the adhesion of one of the ‘low-adhesion’ lines when the plates were coated with a low concentration of HA. The adhesion of the remaining ‘low-adhesion’ line was slightly increased after tunicamycin treatment. It is concluded that glycosylation and not spliced variant content of CD44 affects the adhesive properties of ovarian tumour cells. This conclusion may have important consequences for developing new therapies in ovarian cancer This revised version was published online in July 2006 with corrections to the Cover Date.     

Human ovarian tumour cells can bind hyaluronic acid via membrane CD44: a possible step in peritoneal metastasis

Our previous studies have suggested that the interaction between hyaluronic acid (HA) on peritoneal mesothelial cells and the membrane adhesion molecule, CD44, on ovarian tumour cells could be important in ovarian cancer metastasis. In order to study this further, adhesion of six ovarian tumour lines to HA coated on to a plastic surface was investigated. Four lines bound to the HA coat and two lines did not. The adhesive lines were those that expressed high amounts of CD44, but the degree of adhesion was not closely correlated with CD44 expression. The results suggested that different tumour lines had different affinities for HA. Treatment of the HA coat with hyaluronidase substantially reduced adhesion. Adhesion was also partially reduced if the tumour cells were preincubated with either soluble HA, or anti-CD44 antibodies directed against the HA binding region. An antibody against a non-HA binding region only slightly blocked adhesion at high antibody concentrations. Only the CD44H isoform was detected by immunoprecipitation on the tumour cells. These results suggest that ovarian tumour cells can attach to immobilised HA via CD44H on the cell membrane.     

转移相关分子链Actin-CD44-MMP-2在乳腺癌转移实验中的改变

目的 研究乳腺癌转移相关的分子机制及抑制体内外转移的作用和机制.方法 选择高、低转移性乳腺癌细胞系BICR-H1和MCF-7,用明胶底物非变性电泳分析法、Western blot和免疫荧光染色等方法,观察肌动蛋白、CD44和基质金属蛋白酶2分子链(ACM)成员分子的定性与定位关系.利用荧光标记肿瘤鸡胚尿囊膜(CAM)模型,血管内注射顺铂或MMP-2C末端PEX融合蛋白,利用荧光显微镜直接观察鸡胚肺转移抑制情况与癌细胞的ACM水平.结果 高转移的BICR-H1细胞ACM分子链呈高表达,分子定位相互关联.低转移性的MCF-7细胞呈低表达或无表达.体外实验中,顺铂和PEX分别抑制了CD44和MMP-2的表达.体内实验中,5-30μg顺铂能够抑制BICR-H1和MCF-7肿瘤的体内生长,呈剂量依赖性.30μg顺铂使乳腺癌BICR-H1细胞体内转移克隆数下降到(8±6)个[对照组为(30±15)个],而同剂量PEX可以完全抑制其体内转移.结论 ACM分子链表达与乳腺癌的转移性密切相关.顺铂和PEX分别通过封闭ACM分子链的环节,使CD44或MMP-2表达抑制,从而抑制乳腺癌细胞的体内外生长和转移.