ABSTRACT
Multiple myeloma is a hematologic neoplasm caused by an uncontrolled clonal proliferation of neoplastic plasma cells (nPCs) in the bone marrow. The development and survival of this disease is tightly related to the bone marrow environment. Proliferation and viability of nPCs depend on their interaction with the stromal cells and the extracellular matrix components, which also influences the appearance of drug resistance. Recapitulating these interactions in an in vitro culture requires 3D environments that incorporate the biomolecules of interest. In this work, we studied the proliferation and viability of three multiple myeloma cell lines in a microgel consisting of biostable microspheres with fibronectin (FN) on their surfaces. We also showed that the interaction of the RPMI8226 cell line with FN induced cell arrest in the G0/G1 cell cycle phase. RPMI8226 cells developed a significant resistance to dexamethasone, which was reduced when they were treated with dexamethasone and bortezomib in combination.
ABSTRACT
The development of three-dimensional environments to mimic the in vivo cellular response is a problem in the building of disease models. This study aimed to synthesize and validate three-dimensional support for culturing monoclonal plasma cells (mPCs) as a disease model for multiple myeloma. The three-dimensional environment is a biomimetic microgel formed by alginate microspheres and produced on a microfluidic device whose surface has been functionalized by a layer-by-layer process with components of the bone marrow's extracellular matrix, which will interact with mPC. As a proof of concept, RPMI 8226 cell line cells were cultured in our 3D culture platform. We proved that hyaluronic acid significantly increased cell proliferation and corroborated its role in inducing resistance to dexamethasone. Despite collagen type I having no effect on proliferation, it generated significant resistance to dexamethasone. Additionally, it was evidenced that both biomolecules were unable to induce resistance to bortezomib. These results validate the functionalized microgels as a 3D culture system that emulates the interaction between tumoral cells and the bone marrow extracellular matrix. This 3D environment could be a valuable culture system to test antitumoral drugs efficiency in multiple myeloma.
ABSTRACT
Stem cells reside in niches, specialized microenvironments that sustain and regulate their fate. Extracellular matrix (ECM), paracrine factors or other cells are key niche regulating elements. As the conventional 2D cell culture lacks these elements, it can alter the properties of naïve stem cells. In this work we designed a novel biomimetic microenvironment for cell culture, consisting of magnetic microspheres, prepared with acrylates and acrylic acid copolymers and functionalized with fibronectin or hyaluronic acid as ECM coatings. To characterize cell proliferation and adhesion, porcine mesenchymal stem cells (MSCs) were grown with the different microspheres. The results showed that the 3D environments presented similar proliferation to the 2D culture and that fibronectin allows cell adhesion, while hyaluronic acid hinders it. In the 3D environments, cells reorganize the microspheres to grow in aggregates, highlighting the advantages of microspheres as 3D environments and allowing the cells to adapt the environment to their requirements.
