Biomarkers of Cancer Stem Cells in Glioblastoma Multiforme and Histological Picture of Cancer

Abstract

Introduction: Glioblastoma (GBM) is the most aggressive primary brain cancer. A number of stem cell markers, including cancer and specifically GBM, have been identified and well described in literature. However, no attempts have been made to determine a relation between the expression of cancer stem cell markers in GBM and morphological features of this tumor. Therefore, the present study attempts to compare the expression of stem cell markers found in GBM tissue with selected features of tumor malignancy.Material and Methods: 21 GBM samples were tested. In the assessment of GBM histological features, the following were considered: nuclear pleomorphism, Ki-67 labeling index and endothelial proliferation. The expression of CD133, GFAP, Nestin, βIIItubulin, Oct-4, Nanog, Olig2 and Rex was analyzed by reverse transcription polymerase chain reaction.Results: A significantly higher expression of CD133 (p = 0,0007) and Nestin (p = 0,0216) were found in GBM with evident nuclear pleomorphism. We found also significantly higher expression of CD133, Nestin and Olig2 in patients with a Ki-67 labeling index over 15% (p = 0.0033, p = 0.0101, and p = 0.0066). Conclusion:The expression of biomarkers of stem cells in GBM is associated with a greater severity of anaplasia and tumor proliferative activity. So, it can be assumed that the aggressiveness of GBM is at least partly due to the presence of cancer stem cells in the tumor mass. Due to the resistance of these cells to radio-and chemotherapy, the described phenomena may be associated with lower therapeutic efficacy in patients with GBM.