Type-I Collagen/Collagenase Modulates the 3D Structure and Behavior of Glioblastoma Spheroid Models

Abstract

Multicellular tumor spheroids have emerged as well-structured, three-dimensional culture models that resemble and mimic the complexity of the dense and hypoxic cancer microenvironment. However, in brain tumor studies, a variety of glioblastoma multiforme (GBM) cell lines only self-assemble into loose cellular aggregates, lacking the properties of actual glioma tumors in humans. In this study, we used type-I collagen as an extracellular matrix component to promote the compaction of GBM aggregates forming tight spheroids to understand how collagen influences the properties of tumors, such as their growth, proliferation, and invasion, and collagenase to promote collagen degradation. The GBM cell lines U87MG, T98G, and A172, as well as the medulloblastoma cell line UW473, were used as standard cell lines that do not spontaneously self-assemble into spheroids, and GBM U251 was used as a self-assembling cell line. According to the findings, all cell lines formed tight spheroids at collagen concentrations higher than 15.0 μg mL–1. Collagen was distributed along the spheroid, similarly to that observed in invasive GBM tumors, and decreased cell migration with no effect on the cellular uptake of small active molecules, as demonstrated by uptake studies using the photosensitizer verteporfin. The enzymatic cleavage of collagen affected spheroid morphology and increased cell migration while maintaining cell viability. Such behaviors are relevant to the physiological models of GBM tumors and are useful for better understanding cell migration and the in vivo infiltration path, drug screening, and kinetics of progression of GBM tumors.

The Extracellular Matrix in Glioblastomas: A Glance at Its Structural Modifications in Shaping the Tumoral Microenvironment—A Systematic Review

“…Actually, different subtypes of collagen have been investigated over the years and are related to GBM invasiveness. Recent findings have shown that GBM cell lines form tight spheroids in the presence of type I collagen and that the enzymatic cleavage of collagen affects spheroid morphology and increases cell migration [ 23 ]. In particular, the collagen alpha-2(I) chain (COL1A2) was found to be upregulated in GBMs compared with normal brain tissue, and it is related to poor progression-free survival and overall survival [ 24 ].…”

Advanced 3D Models of Human Brain Tissue Using Neural Cell Lines: State-of-the-Art and Future Prospects

“…The applications of the 3D in vitro models described in Table 2 , Table 4 and Table 5 can be divided into three main fields: oncology, neurodegenerative diseases, and neurotoxicity. Most of the studies described in this review employ 3D neural models for inspecting their responses against drugs, treatments, and chemotherapeutic agents (e.g., temozolomide, epigallocatechin gallate, natural killer cells, nanoparticles, and rotenone) [ 33 , 34 , 35 , 41 , 42 , 70 , 91 , 92 ]. For these studies, the 3D models represent an advanced tool more closely resembling the characteristics of in vivo tumor tissues.…”

Recent methods of droplet microfluidics and their applications in spheroids and organoids

“…The hydrogels used in tumour spheroid formation can be derived from the natural ECMs of the tumour stroma ( e.g. , Matrigel, 118 collagen, 119 and hyaluronic acid 120 ), natural materials ( e.g. , agarose 58 and alginate 59 ), or synthetic polymers ( e.g.…”

“…116,117 From the macroscopic view, tumour spheroids can be created by embedding individual cells into 3D hydrogel scaffolds. The hydrogels used in tumour spheroid formation can be derived from the natural ECMs of the tumour stroma (e.g., Matrigel, 118 collagen, 119 and hyaluronic acid 120 ), natural materials (e.g., agarose 58 and alginate 59 ), or synthetic polymers (e.g., PEG). 60 In the microfluidic device, the formation of tumour spheroids normally starts with the allocation of cells into individual hydrogel microparticles/ microcapsules, followed by the growth of cells into spheroids.…”