Effectiveness of Tumor-Induced Mesenchymal Stem Cells on Cell Growth and Development in Different Cancer Types In Vitro and In Vivo Models

Abstract

Background

Mesenchymal stem cells (MSCs) are present in almost all tissue types. They have multipotent properties and unique abilities to self-renew and differentiate into various cell types. We evaluated the effect of MSCs pretreated with tumor factors on three different types of common, difficult to detect cancers using several cell-based assays such as cell viability and proliferation assay, scratch assays, migration assays, and in vivo assays.

Methods

We co-cultured each type of these common cancers with either control MSCs (control TERT-GFP cells) or MSCs that were pretreated with tumor factors (conditioned medium [CM]- induced TERT-GFP cells) and compared changes in cell morphology and growth, cell proliferation, cell migration, and colony formation in an in vitro model. Moreover, we examined the changes in these cancers after injection with control TERT-GFP cells (untreated) and CM- induced TERT-GFP cells in an in vivo model.

Results

We detected an increase in cell proliferation of each cancer cell line when co-cultured with normal MCSs. Only HT-29 colorectal adenocarcinoma cells co-cultured with CM-induced TERT-GFP cells showed a significant reduction in cell proliferation. We observed that pre-exposure of MSCs to tumor factors decreased the attraction/migration of MSCs towards all studied tumor cell types, particularly HT-29 cells. MSCs pre-exposed to tumor factors that were co-cultured with tumor cells significantly influenced the wound healing of these cells and tumor factors markedly decreased colony formation in colorectal cancer cells.

Conclusions

Our results suggest that coculture of MSCs with tumor factors for 1 wk can suppress cancer cells, especially colorectal cancer cells.