The effect of temozolomide on apoptosis-related gene expression changes in glioblastoma cells.

BACKGROUND: Glioblastoma (GB) is the most common and biologically the most aggressive primary brain tumor of the central nervous system (CNS) in adults. Standard treatment for newly diagnosed GB consists of surgical resection, radiotherapy, and chemotherapy with temozolomide (TMZ). Despite numbers of studies, a resistance to chemotherapy is the major obstacle to successful GB treatment. OBJECTIVES: The aim of our study was to detect the sensitivity of glioblastoma T98G cells to TMZ treatment and subsequently to determine the expression changes of apoptosis-associated genes in glioblastoma cells. MATERIAL AND METHODS: The human glioblastoma cell line (T98G) was treated with specified concentrations of TMZ during different time periods. Their viability was measured by colorimetric MTT assay and the activation of the apoptotic pathway was determined by measuring the caspase 3/7 activity. Commercial pre-designed microfluidic array was used to quantify expression of human apoptosis-associated genes. RESULTS: The untreated control of T98G cell line against human brain total RNA standards reported significant changes in several apoptotic genes expression levels. We identified also a deregulation in geneexpression levels between the TMZ treated and untreated T98G cells associated with apoptotic pathways. After 48 hours of exposure of T98G cells to TMZ, we observed a significant deregulation ofseven genes: BBC3, BCL2L1, RIPK1, CASP3, BIRC2, CARD6 and DAPK1. These results can contribute to the importance of apoptosis in glioblastoma cells metabolism and effect of TMZ treatment. CONCLUSIONS: Identification of apoptotic gene panel in T98G cell line could help to improve understanding of brain tumor cells metabolism. Recognizing of the pro-apoptotic and anti-apoptotic genes expression changes could contribute to clarify the sensitivity to TMZ therapy and molecular base in healthy and tumor cells (Tab. 1, Fig. 2, Ref. 48).