CD44 cleavage induced by a membrane-associated metalloprotease plays a critical role in tumor cell migration (original) (raw)

Proteolytic Cleavage of the CD44 Adhesion Molecule in Multiple Human Tumors

American Journal of Pathology, 2002

Cell surface adhesion molecules are crucial for the development and/or pathogenesis of various diseases including cancer. CD44 has received much interest as a major adhesion molecule that is involved in tumor progression. We have previously demonstrated that the ectodomain of CD44 undergoes proteolytic cleavage by membrane-associated metalloproteases in various tumor cell lines. The remaining membranebound CD44 cleavage product can be detected using antibodies against the cytoplasmic domain of CD44 (anti-CD44cyto antibody). However, the cleavage of CD44 in primary human tumors has not been investigated. Using Western blots with anti-CD44cyto antibody to assay human tumor tissues, we show that the CD44 cleavage product can be detected in 58% (42 of 72) of gliomas but not in normal brain. Enhanced CD44 cleavage was also found in 67% (28 of 42) of breast carcinomas, 45% (5 of 11) of non-small cell lung carcinomas, 90% (9 of 10) of colon carcinomas, and 25% (3 of 12) of ovarian carcinomas. Tumors expressing a CD44 splice variant showed a significantly higher incidence of enhanced CD44 cleavage. The wide prevalence of CD44 cleavage suggests that it plays an important role in the pathogenesis of human tumors. CD44 is a widely distributed cell-surface adhesion molecule that is implicated in a diverse range of physiological and pathological processes, including lymphocyte homing and activation, cell-matrix interactions, cell migration, and the regulation of tumor growth and metastasis. 1 The gene encoding the CD44 protein contains 20 exons of which up to 10 variant exons encoding a portion of the ectodomain are alternatively spliced in various combinations, thereby generating numerous CD44 splice variant isoforms (CD44v). 1,2 The standard CD44 (CD44s) lacks all variant exons. All forms of CD44 are heavily glycosylated to varying degrees. The diversity of CD44 functions is compounded by its variable structure. 3-5 The expression of CD44 or its variants has been shown to be associated with tumor progression; however, the data concerning CD44v forms is controversial for some tumors. 1,6 -13 Thus, the exact role of CD44 in the progression of human tumors remains obscure and increased interest has been directed at elucidating the possible mechanisms by which CD44 plays a role in human tumors.

CD44 Attenuates Metastatic Invasion during Breast Cancer Progression

2005

Metastatic invasion is the primary cause of breast cancer mortality, and adhesion receptors, such as CD44, are believed to be critical in this process. Historically, primary breast tumor epithelium has been investigated in isolation from other tissue components, leading to the common interpretation that CD44 and its primary ligand, hyaluronan, promote invasion. Here, we provide in vivo evidence showing CD44 antagonism to breast cancer metastasis. In a mouse model of spontaneously metastasizing breast cancer (MMTV-PyV mT), we found that loss of CD44 promotes metastasis to the lung. Localization studies, in combination with a novel hyaluronan synthase-GFP transgenic mouse, show a restricted pattern of expression for CD44 and hyaluronan. Whereas CD44 is expressed in tumor epithelium, hyaluronan synthase expression is restricted to stromal-associated cells. This distinct CD44 and hyaluronan pattern of distribution suggests a role for epithelial-stromal interaction in CD44 function. To define the relevance of this spatial regulation, we developed an in vitro invasion assay to emulate invasion into the extracellular matrix. Invasion of CD44-positive tumor cells was inhibited in hyaluronan-containing matrices, whereas blocking CD44-hyaluronan association increased invasion. Collectively, these data show that during breast cancer progression, hyaluronan-CD44 dynamics occurring through epithelialstromal interactions are protective against metastasis. (Cancer Res 2005; 65(15): 6755-63)

Mechanism and biological significance of CD44 cleavage

Cancer Science, 2004

γ γ γ γ-secretase. The intramembranous cleavage generates CD44ICD, which acts as a signal transduction molecule; it is translocated to the nucleus and activates transcription. An understanding of the underlying mechanism of these cleavages of CD44 could provide novel therapeutic targets for cancer cell invasion and metastasis. (Cancer Sci 2004; 95: 930-935)

Engagement of CD44 Promotes Rac Activation and CD44 Cleavage during Tumor Cell Migration

Journal of Biological Chemistry, 2003

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.

The biology and role of CD44 in cancer progression: therapeutic implications

Journal of hematology & oncology, 2018

CD44, a non-kinase transmembrane glycoprotein, is overexpressed in several cell types including cancer stem cells and frequently shows alternative spliced variants that are thought to play a role in cancer development and progression. Hyaluronan, the main ligand for CD44, binds to and activates CD44 resulting in activation of cell signaling pathways that induces cell proliferation, increases cell survival, modulates cytoskeletal changes, and enhances cellular motility. The different functional roles of CD44 standard (CD44s) and specific CD44 variant (CD44v) isoforms are not fully understood. CD44v contain additional peptide motifs that can interact with and sequester growth factors and cytokines at the cell surface thereby functioning as coreceptors to facilitate cell signaling. Moreover, CD44v were expressed in metastasized tumors, whereas switching between CD44v and CD44s may play a role in regulating epithelial to mesenchymal transition (EMT) and in the adaptive plasticity of can...

Function and Expression of CD44 during Spreading, Migration, and Invasion of Murine Carcinoma Cells

Experimental Cell Research, 1998

The cell surface glycoprotein CD44 is proposed as a main participant in cell adhesion and migration. We studied the function, expression, and distribution of CD44 in the invasive and metastatic F3II murine carcinoma cell line during adhesion, spreading, migration, and invasion. A mAb anti-CD44 (KM 201) dramatically blocked F3II cell adhesion on both plastic and hyaluronic acid coatings, as well as spreading on uncoated plastic surfaces (P < 0.01). KM201 mAb significantly inhibited F3II cell migration and invasion in Transwell chambers. Immunocytochemistry of spreading cells revealed that CD44 distributed in bands on the cell surface, particularly in the tip of leading edges and in the perinuclear zones of the cell membrane. CD44 antigen was never detected in filopodia or lamellipodia nor in focal adhesion-like structures, but was also detectable as strong interlamellar bands. Fully spread cells showed a decreased CD44 signal compared to cells in early stages of spreading. This decrease correlated with a reduced expression of CD44 as detected by Western blot. We also investigated the signals that may regulate CD44 expression in F3II cells. Treatment of F3II cells, with phorbol myristate acetate (PMA) or phosphatidic acid (PA, the product of PLD-dependent hydrolysis of phosphatidylcholine), significantly enhanced CD44 expression. Conversely, the treatment of F3II cells with H7, a specific PKC inhibitor, or propranolol, which blocks PA conversion to DAG, significantly decreased CD44 expression levels. These results suggest the involvement of PKC and PLD pathways in CD44 expression. These results demonstrate that CD44 plays an important role during F3II cells adhesion, spreading, migration, and invasion. In addition we provide information linking the PLD-and PKC-dependent pathways with the regulation of CD44 expression.

The role of CD44 in epithelial-mesenchymal transition and cancer development

OncoTargets and therapy, 2015

CD44, a multi-structural and multifunctional transmembrane glycoprotein, was initially identified as a receptor for hyaluronan that participates in both physiological and pathological processes. CD44 is found to be closely linked to the development of various solid tumors. Molecular studies have revealed that high CD44 expression was correlated with the phenotypes of cancer stem cells and epithelial-mesenchymal transition, thereby contributing to tumor invasion, metastasis, recurrence, and chemoresistance. Correspondingly, blockade of CD44 has been demonstrated to be capable of attenuating the malignant phenotype, slowing cancer progression, and reversing therapy resistance. Clinical analyses showed that high CD44 expression is associated with poor survival of various cancer patients, indicating that CD44 can be a potential prognostic marker. In this review, we summarize recent research progress of CD44 on tumor biology and the clinical significance of CD44.

CD44 Modulates Hs578T Human Breast Cancer Cell Adhesion, Migration, and Invasiveness

Experimental and Molecular Pathology, 1999

CD44 is an adhesion molecule that has been implicated in tumor INTRODUCTION progression of epithelial and nonepithelial tumors. One of its variants, CD44v6, is involved in the production of experimental metastasis. Previous reports have indicated that in human breast cancer the overex-Tumor cell invasion is composed of a minimum of four pression of CD44, and moreover the presence of CD44v6, correlated steps: cell adhesion to the extracellular matrix, degradation with poor prognosis. This study focuses on the role of these molecules in in vitro invasion of breast cancer cells. The effect of antibodies of the extracellular matrix components, and tumor cell motilagainst all CD44 isoforms and CD44v6 was evaluated in different in ity followed by cell detachment (Babaï, 1976; Fidler et al., vitro experimental assays that are closely related to tumor cell invasion 1978; Liotta, 1986). Homotypic cell-cell interactions and in vivo: adhesion to hyaluronan and purified extracellular matrix comcell-matrix interactions are involved in each of those steps ponents; cell motility; haptotaxis; and invasion of purified extracellular (reviewed in Hart and Saini, 1992; and in Behrens, 1993). matrix components. The highly metastatic human breast cancer cell line Hs578T was used in all assays. Our results show that both antibod-A restricted number of cell-associated proteins can fulfill ies have a blocking effect on cell migration, on haptotatic migration, this dual role. One of them is CD44, which encompasses a on in vitro invasion, and on adhesion to hyaluronan and purified extrafamily of cell adhesion glycoprotein isoforms (reviewed in cellular matrix components. In conclusion, our data show that, in Rudzki and Jothy, 1997; Naor et al. 1997). The variant CD44 addition to its participation in adhesion to components of the extracelluisoforms differ from the standard form CD44s (also called lar matrix, CD44v6 is involved in the motility and in invasion of tumoral cells.

CD44H regulates tumor cell migration on hyaluronate-coated substrate

Journal of Cell Biology, 1992

CD44 is a broadly distributed cell surface glycoprotein expressed in different isoforms in various tissues and cell lines. One of two recently characterized human isoforms, CD44H, is a cell surface receptor for hyaluronate, suggesting a role in the regulation of cell-cell and cell-substrate interactions as well as of cell migration. While CD44H has been shown to mediate cell adhesion, direct demonstration that CD44H expression promotes cell motility has been lacking. In this work we show that a human melanoma cell line, stably transfected with CD44H, displays enhanced motility on hyaluronate-coated surfaces while transfectants expressing an isoform that does not bind hyaluronate, CD44E, fail to do so. Migration of CD44H-expressing transfectants is observed to be blocked by a soluble CD44-immunoglobulin fusion protein as well as by anti-CD44 antibody, and to depend on the presence of the cytoplasmic domain of CD44. However, cells expressing CD44H cytoplasmic deletion mutants retain s...