Growth Factors from Tumor Microenvironment Possibly Promote the Proliferation of Glioblastoma-Derived Stem-like Cells in Vitro

Glioblastoma multiform is a lethal brain glial tumor characterized by low survival and high recurrence, partially attributed to the glioblastoma stem cells according to recent researches. Microenvironment or niche in tumor tissue is believed to provide essential support for the aberrant growth of tumor stem cells. In order to explore the effect of growth factors in tumor microenvironment on glioblastoma stem cells behavior, glioblastoma-derived stem-like cells (GDSCs) were isolated from adult human glioblastoma specimen with antibody against surface marker CD133 and were co-cultured with various tumor cells including U87MG cells, unsorted glioblastoma tumor cells, CD133(-) cells and normal rat primary astrocytes. Results suggested that tumor cells could promote GDSCs proliferation while non-tumor cells could not, and several growth factors were exclusively detected in the co-culture system with tumor cells. It was concluded that growth factors derived from tumor microenvironment possibly contributed to the uncontrolled proliferation of GDSCs.