Chemotaxis towards hyaluronan is dependent on CD44 expression and modulated by cell type variation in CD44-hyaluronan binding

Abstract

The accumulation of the extracellular matrix glycosaminoglycan hyaluronan by tumours and tumour-associated stroma promotes cancer cell invasion and metastasis. Using the Dunn chamber chemotaxis assay, we demonstrate for the first time that high molecular mass hyaluronan acts as a soluble chemoattractant promoting the directional migration of MDA-MB-468 and MDA-MB-231 breast cancer cells. Moreover, chemotaxis towards hyaluronan, but not foetal bovine serum, can be abrogated following treatment of the cells with siRNA oligonucleotides to downregulate CD44 expression. These data indicate that CD44 is the principal receptor mediating this response and that CD44 expression is not a general requirement for cell migration and gradient sensing, rather it elicits a ligand-specific response. However, expression of CD44 alone is not sufficient to drive chemotaxis towards hyaluronan, as NIH-3T3 fibroblasts were unable to respond to a hyaluronan gradient even when transfected with high levels of human CD44. For NIH-3T3 cells to bind exogenous hyaluronan, it was necessary to both increase the level of receptor expression and remove a hyaluronan pericellular matrix. Together, these studies reveal a direct mechanism for promoting cell invasion into the hyaluronan-rich matrix and predict that in the complex multicellular environment in vivo, multiple mechanisms exist to regulate the ability of a cell to respond to a chemotactic hyaluronan gradient.

Hyaluronan is required for cranial neural crest cells migration and craniofacial development

“…In breast cancer cell lines, hyaluronan seems to play a chemoattractant role in the directional migration of malignant cells in a CD44 activity-dependent manner (Tzircotis et al, 2005). In vivo, it has been demonstrated that hyaluronan is required for zebrafish gastrulation movements (Bakkers et al, 2004) and we highlighted that both hyaluronan and CD44 are involved in muscle cell precursors migration during Xenopus laevis development (Ori et al, 2006).…”

“…These findings suggest that the formation of hyaluronan-versican complexes may help to facilitate cranial NCC migration. Hyaluronan can promote cell locomotion also by interacting with cell membrane receptors, which modulate cell adhesion and trigger intracellular signaling (Bourguignon et al, 1997;Banerji et al, 1999;Tzircotis et al, 2005). The finding that CD44 down-regulated embryos exhibit an NCC migration delayed phenotype, similar to that observed in embryos depleted of both Has1 and Has2, suggests that CD44 could mediate the hyaluronan instructive effect that initiates signaling pathways and thus promotes NCC movements.…”

Directional sensing of a phorbol ester gradient requires CD44 and is regulated by CD44 phosphorylation

“…Chemotaxis was measured by direct observation and recording of cell behaviour in stable concentration gradients using Dunn chemotaxis chambers (Hawksley Technology, Lancing, UK) as described previously (Zicha et al, 1991;Allen et al, 1998;Tzircotis et al, 2005). Briefly, glass coverslips were coated with 1 mg/ml laminin (BD Biosciences, Cowley, UK) in PBS for 1 h at room temperature, washed twice with DMEM and then seeded with 5 Â 10 4 cells per coverslip.…”

“…First, expression of CD44 by the tumour cells can increase the interaction with endothelial cells and transmigration across an endothelial monolayer (Fujisaki et al, 1999;Mine et al, 2003;Draffin et al, 2004;Ratliff, 2005). Second, in a wide variety of systems, increased CD44 expression has been shown to correlate strongly with increased invasive potential of tumour cells Jothy, 1999, 2001;Dingemans et al, 2002;Kobayashi et al, 2002;Bourguignon et al, 2003;Xu and Yu, 2003;Kim et al, 2004;Miletti-Gonzalez et al, 2005) and in particular, increasing evidence points to an important role for CD44 in mediating directional cell migration (Alstergren et al, 2004;Avigdor et al, 2004;Zhu et al, 2004Zhu et al, , 2005Miletti-Gonzalez et al, 2005;Tzircotis et al, 2005).…”

AFM as a tool to probe and manipulate cellular processes

“…Very localised stimuli at the cell surface often initiate intracellular signals and mechanical responses that are crucial in a number of cell processes such as chemotaxis and focal adhesion assembly. For example, HA can be an important chemoattractant molecule controlling the invasion of cancer cells [81]. Oliferenko et al have shown that the local application of an HA microgradient to glioblastoma cells induces major lamellipodia outgrowth via a rac-1-dependent signalling pathway [82].…”