Localized delivery of chemokine for in vitro manipulation of hepatocellular carcinoma cell behaviors during the epithelial-mesenchymal transition.

ABSTRACT

Hepatocellular carcinoma develops within an altered mechanical and biochemical environment. The chemokine C-X-C motif chemokine ligand 12 plays an important role in tumor cell metastasis during the process of the epithelial-mesenchymal transition. Here, we successfully engineered a biomimetic matrix made up of polyelectrolyte films with appropriate stiffness, which could present C-X-C motif chemokine ligand 12 in an immobilized status in a spatially controlled manner. The adsorbed amounts of C-X-C motif chemokine ligand 12 could be precisely adjusted over a large range from 27 ng/cm2 to 2.6 µg/cm2. Immobilized C-X-C motif chemokine ligand 12 induced an obvious increase in hepatocellular carcinoma cell adhesion, spreading, and migration in a dose-dependent manner. The phenomenon was associated with proportion changes of three phenotypes of cell morphology (round, polygonal, and elongated) and higher concentrations of immobilized C-X-C motif chemokine ligand 12 led to the rising number of elongated cells along with up-regulation of the mesenchymal markers, as a critical step in epithelial-mesenchymal transition. CD44 and integrin αvß3 revealed the spatial coincidence in three cell phenotypes. Immobilized C-X-C motif chemokine ligand 12-induced ERK phosphorylation also exhibited dose-dependent manner. Our results highlight that an engineered matrix to locally deliver chemokine exhibits the potential to manipulate important cellular responses (including adhesion, spreading, migration, morphology, distribution of surface receptors, and signaling pathways) in the epithelial-mesenchymal transition process during hepatocellular carcinoma development.