The role of cell adhesion proteins—laminin and fibronectin—in the movement of malignant and metastatic cells

Summary Metastasizing tumor cells must traverse diverse extracellular matrices during dissemination. Extracellular matrices consist of two basic types, interstitial stroma and basement membranes. Extracellular matrices are chemically complex structures that interact with cell surfaces by a number of mechanisms. There has been a great deal of effort in recent years to understand the molecular nature of extracellular matrices, especially as it relates to the adhesion of normal and malignant cell types. Adhesive noncollagenous glycoproteins, such as laminin and fibronectin, serve pivotal roles in basement membrane and stromal matrices, respectively. These proteins participate in establishing the architecture of extracellular matrices as well as in attaching to the surface of cells and affecting cellular phenotype. This phenotypic effect ranges from adhesion and motility to growth and differentiation. Changes in adhesive characteristics and motility of cells have long been suspected to play a role in mediating the spread of malignant neoplasms. This article is designed to review extracellular matrix constituents that are currently known that can mediate the adhesion and motility of malignant neoplasms. The adhesion of normal and malignant cells to matrices is a complex process mediated by several distinct mechanisms which are initially manifested by changes in cytoskeletal architecture. The topic of normal and malignant cell adhesion to matrices will also be discussed in this regard, since any explanation of tumor cell migration must account for the complex dynamic interactions of the cell surface with the substratum as well as with the cytoskeleton. Finally, current efforts designed to understant the molecular nature of tumor cell:matrix interactions that contribute to metastatic behavior will also be discussed. The rationale behind these studies is that selective inhibition of specific tumor:extracellular matrix interactions can provide an avenue for therapeutic intervention of metastatic cancer.     

Glycolysis is the primary bioenergetic pathway for cell motility and cytoskeletal remodeling in human prostate and breast cancer cells

The ability of a cancer cell to detach from the primary tumor and move to distant sites is fundamental to a lethal cancer phenotype. Metabolic transformations are associated with highly motile aggressive cellular phenotypes in tumor progression. Here, we report that cancer cell motility requires increased utilization of the glycolytic pathway. Mesenchymal cancer cells exhibited higher aerobic glycolysis compared to epithelial cancer cells while no significant change was observed in mitochondrial ATP production rate. Higher glycolysis was associated with increased rates of cytoskeletal remodeling, greater cell traction forces and faster cell migration, all of which were blocked by inhibition of glycolysis, but not by inhibition of mitochondrial ATP synthesis. Thus, our results demonstrate that cancer cell motility and cytoskeleton rearrangement is energetically dependent on aerobic glycolysis and not oxidative phosphorylation. Mitochondrial derived ATP is insufficient to compensate for inhibition of the glycolytic pathway with regard to cellular motility and CSK rearrangement, implying that localization of ATP derived from glycolytic enzymes near sites of active CSK rearrangement is more important for cell motility than total cellular ATP production rate. These results extend our understanding of cancer cell metabolism, potentially providing a target metabolic pathway associated with aggressive disease.     

The role of myosin I and II in cell motility

Summary It has been recognized since the turn of the century that cell motility by non-muscle cells requires virtually continuous restructuring of the cytoskeleton (see refs [1–4]). It is also clear that cell motility requires a mechanism for converting chemical energy into mechanical work [5]. The proteins actin and myosin, two important constituents of the cytoskeleton, have been postulated to act as the chemicomechanical transducer in motile cells. Central to their role as a force generating mechanism in motile cells is the ability of myosin (a) to hydrolyze ATP when it interacts with actin and (b) to form filaments. Recent studies on mammalian cells and on the cellular slime mold Dictyostelium discoideum have shed light and at the same time raised questions regarding the involvement of myosin in cell motility. Moreover, they have demonstrated the presence of two types of myosins, called myosin II and myosin I, that have unique biochemical and regulatory properties and that may play different roles in mediating cell motility. In this chapter we will discuss the properties of these two myosins and then describe what is known about their involvement in Dictyostelium and mammalian cell motility.     

The control of cell motility during embryogenesis

Summary Morphogenesis is the establishment during development of the complex organization of tissues and organs that characterizes the adult. In multicellular animals, one of the most important processes is morphogenetic movement, the translocation of individual cells or whole tissue rudiments from one site in the body to another. Active cellular locomotion is important in many situations of morphogenetic movement. Characteristically, cell migration in the embryo displays impressive precision: cells at defined sites in the embryo begin migration at particular stages of development, traverse precisely-characterized pathways during migration, and localize finally at particular sites in the body, in specific association with other tissues. One of the most challenging problems of experimental biology is the definition of the mechanisms that regulate the active migration of embryonic cells and tissues. Recent years have seen gratifying progress in this direction, with the definition and characterization of a number of processes of potential importance. This review describes selected instances of morphogenetic movement and contains a discussion of our current understanding of the problem of regulation of cell motility in the embryo.     

Antisense-mediated reduction in thrombospondin-1 expression reduces cell motility in malignant glioma cells.

Thrombospondin-1 (TSP-1) is a multifunctional matrix protein implicated in cancer cell adhesion, migration, invasion, inhibition of angiogenesis and activation of latent transforming growth factor-beta. The involvement of TSP-1 in the motility of malignant glioma cells was investigated by transfection of TSP-1 complementary deoxyribonucleic acid (cDNA) sense and antisense expression vectors into the glioblastoma cell line T98G-G7 that secretes high amounts of TSP-1. TSP-1 production in the 3 antisense cDNA-transfected clones was significantly reduced to 51%, 43% and 47% compared to the host T98G-G7 cells. Motility of the 3 clones was evaluated by invasion assay and compared to the motility of host T98G-G7 cells and 2 sense-transfected clones. Migration of cells was significantly reduced in the 3 antisense-transfected clones with reduced TSP-1 production to 56%, 61% and 43% compared to the host T98G-G7 cells. The host T98G-G7 and another TSP-1-secreting A172 and YMG5 glioblastoma cells were also treated with a synthetic peptide, WSHWSPWSSCSVTCG, which includes 3 consecutive sequences of the adhesion sites in the TSP-1 molecule and with a control peptide. The synthetic peptide significantly inhibited the migration of T98G-G7 and A172 cells in a dose-related manner. Maximum inhibition of migration was achieved by 100 microg/ml of the peptide and the reduction of cell motility compared to untreated cells was 34.6 % and 53.9 %, respectively. On the other hand, the inhibition of migration by the peptide was minimal in YMG5 cells, which secretes a smaller amount of TSP-1 than T98G-G7 and A172 cells. These results suggest that TSP-1 secreted by malignant glioma cells is involved in the motility of glioma cells.     

SIK2 promotes ovarian cancer cell motility and metastasis by phosphorylating MYLK

Salt‐inducible kinase 2 (SIK2; also known as serine/threonine‐protein kinase SIK2) is overexpressed in several cancers and has been implicated in cancer progression. However, the mechanisms by which SIK2 regulates cancer cell motility, migration and metastasis in ovarian cancer have not been fully discovered. Here, we identify that SIK2 promotes ovarian cancer cell motility, migration and metastasis in vitro and in vivo. Mechanistically, SIK2 regulated cancer cell motility and migration by myosin light chain kinase, smooth muscle (MYLK)‐meditated phosphorylation of myosin light chain 2 (MYL2). SIK2 directly phosphorylated MYLK at Ser343 and activated its downstream effector MYL2, promoting ovarian cancer cell motility and metastasis. In addition, we found that adipocytes induced SIK2 phosphorylation at Ser358 and MYLK phosphorylation at Ser343, enhancing ovarian cancer cell motility. Moreover, SIK2 protein expression was positively correlated with the expression of MYLK‐pS343 in ovarian cancer cell lines and tissues. The co‐expression of SIK2 and MYLK‐pS343 was associated with reduced median overall survival in human ovarian cancer samples. Taken together, SIK2 positively regulates ovarian cancer motility, migration and metastasis, suggesting that SIK2 is a potential candidate for ovarian cancer treatment.     

食管鳞癌组织中P53与P73蛋白表达及其相关性

目的 探讨食管鳞癌组织中P53与P73蛋白的表达及其相关性.方法 采用免疫组织化学S-P方法检测46例食管鳞癌组织及30例正常黏膜组织中P53和P73蛋白的表达,并分析两者与相关临床特征的关系及两者之间的相关性.结果 在食管鳞癌组织中P53和P73蛋白的表达与其在正常黏膜中的表达差异具有统计学意义(P=0.007,0.008).P53表达与性别和淋巴转移相关(P=0.047,0.028),而与年龄、分化程度、浸润深度和大体分型无关(P>0.05).P73表达与分化程度和淋巴转移相关(P=0.023,0.035);与年龄、性别、浸润深度和大体分型无关(P>0.05).P53和P73在食管鳞癌的表达正相关(r=0.359,P=0.014).结论 P53和P73与食管鳞癌的发生密切相关,而且共同参与食管鳞癌的发展过程.     

Growth factor regulation of integrin-mediated cell motility

Summary Cell motility, a primary component of tumor cell invasion, is a continuum of sequential events in which the cell extends pseudopodia, forms nascent attachments, assembles and contracts the cytoskeleton, and finally, as it translocates forward, disengages distal adhesions. What triggers cells to move? Substratum contact mediated by integrin adhesion receptors is important, but other signals such as chemokinetic factors appear to be required for continued crawling. It is now apparent that integrins do not simply bind cells to matrix in a Velcrolike fashion, but also are potent signaling molecules. Initial engagement of integrins induces their condensation into focal contacts, forming anchors to the extracellular matrix and discrete signal-transducing complexes on the cytoplasmic surface. A number of growth factors, through either autocrine or paracrine pathways, can activate the cellular machinery that mobilizes the cell. Thus, these two classes of receptors - the integrin receptors that bind specific extracellular adhesion molecules, and growth factor receptors that bind their respective ligands - can regulate cell locomotion. Not surprisingly, there is cross-talk between integrin and growth factor receptors that occurs through their common intracellular signaling pathways. In this way, each receptor type can either amplify or attenuate the other's signal and downstream response. An example of growth factor-induced motility is the epithelial-mesenchymal transition induced by hepatocyte growth factor/scatter factor (HGF/SF). When bound to its receptor, the c-met proto-oncogene product, HGF/SF induces a phenotypic conversion that appears to be an important aspect of tumor progression in malignant carcinomas. The motogenic response produced by HGF/SF in carcinoma cells occurs in discrete steps in which integrins and focal adhesion kinase (p125^FAK) are first recruited to focal contacts. This is rapidly followed by cell spreading, disruption of focal adhesions and cell-cell contacts, and, finally, cell crawling. The precise mechanism by which growth factors such as HGF/SF and its receptor induce this motogenic response and modulate integrin function has not been clearly defined but appears to involve several signaling pathways. Understanding the process by which growth factor and integrin receptors interact and regulate motility may suggest novel targets for therapeutic intervention.     

3-O-methylfunicone produced by penicillium pinophilum affects cell motility of breast cancer cells, downregulating alphavbeta5 integrin and inhibiting metalloproteinase-9 secretion

Recent evidence assigns integrins and metalloproteinases (MMPs) an important role in regulating tumor cell progression. Here, we demonstrate that 3-O-methylfunicone (OMF), a secondary metabolite produced by Penicillium pinophilum, affects cell proliferation and motility of breast cancer MCF-7 cells, downregulating alphavbeta5 integrin, and inhibiting MMP-9 secretion. This effect was absent when the non-tumoral MCF-10 cell line was used. Inhibition of cell motility was also associated to modifications in cell shape and in the distribution of tubulin fibers of OMF-treated MCF-7 cells. In addition, a possible effect on survivin and hTERT was also investigated. We found that OMF strongly inhibits survivin and hTERT gene expression. The results of this study indicate that OMF-induced inhibition of cell motility may be mediated through the modulation of alphavbeta5 integrin and MMP-9 secretion. In addition, the inhibition of typical markers of tumor progression such as hTERT and survivin in MCF-7 and their inactivity towards MCF10 provide strong evidence for a potential use of OMF in anticancer therapy.     

热休克蛋白在食管鳞癌中的表达及其意义

目的探讨热休克蛋白（HSPs）HSP27、HSP60、HSPT0和HSP90d在食管鳞癌及其切缘正常食管黏膜中的表达及其意义。方法168例食管鳞癌和42例切缘正常食管黏膜制成组织芯片,应用免疫组化EnVision法及Westernbolt检测HSP27、HSP60、HSP70和HSP90α在组织中的表达情况,分析4种HSPs的表达与肿瘤位置、肿瘤长度、浸润深度、分化程度和淋巴结转移的关系。结果食管鳞癌和切缘正常食管黏膜中,HSP27的阳性率分别为62．0％和42．1％;HSP60的阳性率分别为92．7％和63．2％;HSP70的阳性率分别为57．9％和22．2％;HSP90α的阳性率分别为33．7％和18．5％。统计学分析结果表明,HSP60和HSP70在食管鳞癌的表达均高于切缘正常食管黏膜（P〈0．01）,HSP27和HSP90α在食管鳞癌与切缘正常黏膜的表达差异均无统计学意义（P〉0．05）。除HSP27的表达随着食管鳞癌分化程度的降低而降低（P〈0．05）外,其他3种HSPs的表达与食管鳞癌的临床病理特征无关（P〉0．05）。结论HSP27、HSP60、HSPT0和HSP90α在食管鳞癌和切缘正常食管黏膜中均有表达。HSP60和HSP70在食管鳞癌的表达高于切缘正常食管黏膜,可能与食管鳞癌的生物学行为有关;HSP27的表达随食管鳞癌分化程度的降低而降低,HSP27的高表达可能影响鳞癌的分化程度。     

非小细胞肺癌细胞分泌蛋白谱的鉴定

目的筛选非小细胞肺癌潜在的早期诊断标志物，对非小细胞肺癌细胞系A549的分泌蛋白进行鉴定。方法收集A549细胞培养上清中的蛋白进行蛋白双向电泳，应用基质辅助激光解析电离飞行时间质谱（MALDI—TOF—MS）及生物信息学鉴定A549凝胶上特有的蛋白质点。结果鉴定出人属的蛋白质点17个，包括α肌动蛋白，γ肌动蛋白，α烯醇酶（ENO1），锰-超氧化物歧化酶（MnSOD），谷胱甘肽S转移酶P（GSTP1—1），Dihydrodiol dehydrogenase 2（DDH），磷酸甘油酸变位酶1（PGAM1），葡萄糖依赖性胰岛素释放肽受体（GIPR），肽基脯氨基顺反异构酶（PPIA），磷脂酰乙醇胺结合蛋白（PEBP），蛋白基因产物9．5（PGP9．5），Peroxiredoxin1（PDX1），Galectin-1及专利蛋白WO0222660等。结论该研究为非小细胞肺癌早期诊断标志物的筛选提供了新的方法和候选分子。     

Role of bone morphogenetic proteins in transitional cell carcinoma cells

Bone morphogenetic proteins (BMPs) are pleiotropic growth factors that signal through an interaction with the membrane receptors-type--IA, -IB, and -II (BMP-RIA, -RIB, and -RII, respectively). Although the prototypical members of this group of growth factors were isolated as osteoinductive factors, recently accumulated data have suggested that these factors regulate malignant cells. Herein, we review the data concerning BMPs in transitional cell carcinoma cells.     

Flavonoid apigenin inhibits motility and invasiveness of carcinoma cells in vitro

Investigations of the mechanisms of the cancer-preventive activity of apigenin (4',5,7,-trihydroxyflavone), a plant-derived, anti-carcinogenic flavonoid, showed its interference with cell proliferation, survival, and gap junctional coupling. We used a model based on non-invasive HeLa wild-type cells and their connexin43 (Cx43) transfected counterparts to correlate the effect of apigenin on tumour cell invasiveness with its influence on cell motility. Both cell lines displayed similar motile properties in control conditions. Apigenin treatment resulted in a significant and reversible inhibition of translocation of both HeLa wild-type cells and HeLa Cx43 transfectants. The effect of apigenin on cell proliferation was less pronounced especially at low apigenin concentration, whereas its influence on cell motility correlated with the reduction of the invasive potential of HeLa Cx43 cells as shown by an invasion assay based on the confrontation of tumour cell spheroids with chick embryo heart fragments. HeLa Cx43 cells were highly invasive in controls, but did not invade the heart tissue at tumour cell aggregate-fibroblast capsule interfaces in the presence of apigenin and failed to fully engulf these heart fragments. Because the motility of chick heart fibroblasts was only slightly affected by apigenin, these observations indicate that apigenin exerts its anti-invasive effect on HeLa cells predominantly via a specific inhibition of tumour cell motility. This inhibitory effect of apigenin on tumour cell invasiveness in vitro demonstrates that apigenin may exert its anti-tumorigenic effect in vivo via inhibition of tumour cell penetration of the healthy tissue.     

Autocrine motility factor and its receptor: Role in cell locomotion and metastasis

Summary The ability to locomote and migrate is fundamental to the acquisition of invasive and metastatic properties by tumor cells. Autocrine motility factor (AMF) is a 55 kD cytokine produced by various tumor cells which stimulates their in vitro motility and in vivo lung colonizing ability. AMF stimulates cell motility via a receptor-mediated signalling pathway. Signal transduction following binding of AMF to its receptor, a cell surface glycoprotein of 78 kD (gp78) homologous to p53, is mediated by a pertussis toxin sensitive G protein, inositol phosphate production and the phosphorylation of gp78. Cell surface gp78 is localized to the leading and trailing edges of motile cells but following cell permeabilization is found within an extended network of intracellular tubulovesicles. Gp78 tubulovesicles colocalize with microtubules and extension of the tubulovesicular network to the cell periphery is dependent on the presence of intact microtubules. Gp78 labeled vasicles can be induced to translocate between the cell center and periphery by altering intracellular pH as previously described for tubulovesicles labeled by fluid phase uptake. Anti-gp78 mAb added to viable motile cells is localized to large multivesicular bodies which, with time, relocate to the leading edge. Binding of AMF to its receptor induces signal transduction, similar to chemotactic stimulation of neutrophil mobility, as well as the internalization and transport of its receptor to the leading edge stimulating pseudopodial protrusion and cell motility.     

细胞周期调节蛋白在食管癌前病变组织的表达及意义

目的探讨食管癌高发区河南林州市和辉县市内镜活检组织p53、p21、Rb、p16、E2F1和cyclin E的表达变化特征及其与各级病变的关系.方法采用免疫组化卵白素-生物素-过氧化物酶复合物(ABC)方法,分析食管癌高发区食管内镜活检组织p53、p21、Rb、p16、E2F1和cyclin E的表达.结果林州市医院食管内镜活检组织共134例,其中21例食管上皮正常(NOR),45例基底细胞过度增生(BCH),23例间变(DYS),45例原位癌组织(CIS).从NOR→BCH→DYS→CIS,p53和cyclin E的免疫阳性率逐渐增高(P<0.05),分别为23.8%(5/21)、 33.3%(15/45)、56.5%(13/23)和71.1%(32/45);28.6%(6/21)、33.3%(15/45)、56.5%(13/23)和75.6%(34/45);而p21的表达逐渐降低(P<0.05),免疫阳性率分别为71.4%(13/21)、57.8%(26/45)、56.5%(13/23)和 37.8%(17/45).辉县市医院食管内镜活检组织132例,其中NOR 12例,BCH 71例,DYS 27例,CIS 22例.从NOR→BCH→DYS→CIS,Rb和E2F1的免疫阳性率逐渐增高(P<0.05),分别为41.7%(5/12)、62.0%(44/71)、 77.8%(21/27)和90.9%(20/22);50.0%(6/12)、45.0%(32/71)、66.7%(18/27)和68.2%(15/22).而p16的表达逐渐降低(P<0.05),免疫阳性率分别为75.0%(9/12)、73.2%(52/71)、59.3%(16/27)和22.7%(5/22).结论 p53、p21、Rb、p16、E2F1和cyclin E是食管癌变早期重要分子改变,p53、Rb、E2F1和cyclin E的高表达和p21、p16的低表达可能是导致病变持续向癌变方向发生和发展的机制之一.     

Tumor cell adhesion to the extracellular matrix and signal transduction mechanisms implicated in tumor cell motility,invasion and metastasis

Summary The relationship between tumor cell adhesion to the extracellular matrix (ECM) and invasion and metastasis formation is one of the most intensively studied topics in cancer biology within the last 10–15 years. The aberrant molecular relationships between malignant tumor cells and their surrounding ECM have been implicated at virtually every stage of the metastatic process; ranging from steps that involve the local invasion of tumor cells away from the primary tumor to those that are involved in mediating extravasation through microvessel-associated basement membranes at the site(s) of metastasis formation. The complexity of tumor metastasis has required that a reductionist approach be taken in order to identify and relate specific molecular mechanisms involved in tumor cell adhesion to various aspects of tumor metastasis. The intensive research efforts into cell adhesion and tumor cell biology have generated many significant new concepts towards our understanding of the molecular aspects of tumor cell adhesion and metastasis. Our purpose in this article is to briefly summarize the relationship of ECM-stimulated tumor cell adhesion to the processes of tumor cell motility and invasion. This is followed by a discussion of certain aspects of signal transduction pathways that may impact on cell motility, with an emphasis on the relationship between phosphatidylinositol hydrolysis and actin polymerization, as well as certain GTP-binding protein-(G-protein) mediated events that could influence cytoskeletal organization and cell motility. Our emphasis is based on increasing evidence that implicates members of the signal transduction G-proteins in the motility and invasion of many normal and transformed cells.     

非小细胞肺癌中Id蛋白的表达及预后意义

目的：研究4种分化抑制因子（inhibitors of differentiation,Id）Id1,Id2,Id3和Id4在非小细胞肺癌（non-small cell lung cancer,NSCLC）组织中的表达及临床意义.方法：采用免疫组织化学方法检测68例非小细胞肺癌及对应癌旁肺组织中4种Id蛋白的表达水平并探讨其与NSCLC患者临床参数及生存时间的关系.结果：68例非小细胞肺癌中4种Id蛋白表达的阳性率分别为67.4％,89.7％,88.2％和64.7％,高于癌旁组织中的表达（P ＜0.05）;Id1和Id3蛋白与分化程度相关（P＜0.05）,Id2蛋白的表达与患者淋巴结转移正相关（P＜0.05）,4种Id蛋白的表达水平与患者的性别,年龄,组织类型及临床分期无关（P＞0.05）;Id2蛋白阴性与阳性表达的患者术后生存时间具有显著性差异（P＜0.05）.结论：4种Id蛋白在非小细胞肺癌患者中表达上调,Id1和Id3与NSCLC的分化程度相关,Id2蛋白与NSCLC的转移及患者的预后相关,可能作为评价其预后的标志.