Using gain/loss-of-function studies for CD133 we assessed the in vitro self-renewal and in vivo tumor formation capabilities of patient-derived glioblastoma cells.
Because AC133 and 293C antibodies do not detect all CD133 variants in glioblastoma cells, alternate detection methods need to be utilized for complete analysis of CD133 expression and for accurately determining the relationship between CD133 and cancer stem-like cells.
Two cell lines, GBM1 and GBM2, were established from CD133-positive cells sorted on an automagnetic cell separator from dispersed human glioblastoma cells.
We identified a set of genes, the knockdown of which induces a significant decrease in the glioma stem cell marker CD133, indicating a role in the glioblastoma stem-like phenotype.
We reported that WIP knockdown in mtp53-expressing glioblastoma greatly reduced proliferation and growth capacity of cancer stem cell (CSC)-like cells and decreased CSC-like markers, such as hyaluronic acid receptor (CD44), prominin-1 (CD133), yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ).
Immuno-labeling of cathepsins K and X was observed in areas of CD133-positive glioblastoma stem cells, localized around arterioles in their niches that also expressed SDF-1α and CD68. mRNA levels of both cathepsins K and X correlated with mRNA levels of markers of glioblastoma stem cells and their niches.
We hypothesized that CD133+ glioblastoma cells presenting stem-cell properties may express pro-vascular molecules allowing them to form blood vessels de novo.
In this study, by FACS analysis we determined the percentage of CD133 positive cells in three primary cultured cell lines established from glioblastoma patients 10.2%, 69.7% and 27.5%, respectively.
This study revealed for the first time that: a) serum deprivation enriched CD133 expression and demonstrated a direct co-expression between CD133 and drug resistant in GOS-3 cells and b) higher expression of CD133 and drug resistance were found in glioblastoma tissues in comparison to normal brain tissues.
These data indicate that the mechanisms through which CD133+ TSCs respond to radiation are significantly different from those of the traditional glioblastoma in vitro model, established glioma cell lines.
We also demonstrated that human glioblastoma cells previously cultured under high oxygen tension can lose part of their aggressiveness when orthotopically engrafted in SCID mice or lead to tumors with distinct phenotypes and no re-expression of AC133.
To better understand the effect of this tumor on allergies and inflammation, we used CD133 mRNA expression as an indicator of tumor aggressiveness and systematically examined its relation to mRNA expression levels of 919 allergy- and inflammation-related genes in 142 glioblastoma tissue samples.
In our study, glioma stem cells (GSCs) expressing the surface marker CD133 from human glioblastoma cell line U251 were isolated using MACS column and were analyzed using immunofluorescence and flow cytometry (FCM).
We conclude that CD133+ U87 glioblastoma cells derived exosome-mediated miRNA transduction play an important role of mediating a proangiogenic response and glioma cells proliferation, and that the exosomal pathway constitutes a potentially targetable driver of hypoxia-dependent intercellular signaling during tumor development.
Gene expression analysis of CD133+ vs. CD133- cell population from each tumour showed that CD133+ cells presented common characteristics in all glioblastoma samples (up-regulation of genes involved in angiogenesis, permeability and down-regulation of genes implicated in cell assembly, neural cell organization and neurological disorders).
CD9 silencing in three CD133+ glioblastoma cell lines (NCH644, NCH421k and NCH660h) led to decreased cell proliferation, survival, invasion, and self-renewal ability, and altered expression of the stem-cell markers CD133, nestin and SOX2.