Apoptosis-related gene expression in glioblastoma (LN-18) and medulloblastoma (Daoy) cell lines

Abstract

The expression of apoptosis genes in a commercial pre-designed low-density array from Applied Biosystems was evaluated in two human brain cancer cell models, LN-18 and Daoy (HTB-186™) in comparison to the reference human primary endothelial cells under basic conditions. Analysis of the gene expression in the cancer cell lines compared to the normal control revealed features reflecting anti-apoptotic and inflammatory characteristics of the former. There was an overall downregulation of apoptosis-stimulating genes in both cancer cell lines, along with an upregulation of certain apoptosis inhibitors. A number of genes demonstrated statistically significant changes in their expressions, including BAX (BCL2-associated X protein); the CARD4/NLR family, CARD domain containing 4; CASP10 (caspase 10, apoptosis-related cysteine peptidase); DAP1 (death-associated protein kinase 1), and BIRC5 (baculoviral IAP repeat-containing 5). Anti-apoptotic potential in both cell lines was demonstrated by changes in the Bax:Bcl-2 ratio and downregulation of the APAF1 gene in LN18 cells. There was also significant downregulation of extrinsic signals and the TNF/FADD/inflammatory cascade, and upregulation of caspase inhibitors (IAPs). These results provided a novel molecular characterization of important human cancer cell lines, which might provide a useful research tool for investigating the experimental model of the CNS cell.

Fig. 1

List of the genes for which expression in LN18 and Daoy cells was significantly different from the control HUVEC cells. The genes are divided into indicated apoptosis pathways: the TNF receptor pathway, NKkB signaling pathway, Bcl-2 family-regulated pathway, CARD family, caspases, IAP family, and others. Differences in gene expression are presented as fold changes (compared to reference HUVECs), accompanied by corresponding p values (according to [36])

Fig. 2

The Metacore™ apoptosis signaling pathway relating to TNF receptors, NFkB and BCL-2 antiapoptotic family genes. Bars indicate the degree of up- or downregulation of the gene target relative to HUVEC cells; means decreased gene expression. means increased gene expression; height of bars corresponds to the change value. Numbers in symbols indicate: 1 LN18, 2 Daoy cell lines; number of asterisks reflects the statistical significance of the p value (* p < 0.05, ** p < 0.01, *** p < 0.001)

Fig. 3

The Metacore™ apoptosis signaling pathway relating to mitochondrial proteins. Bars indicate the degree of up- or downregulation of the gene target relative to HUVEC cells; means decreased gene expression. means increased gene expression; height of bars corresponds to the change value. Numbers in symbols indicate: 1 LN18, 2 Daoy cell lines; number of asterisks reflects the statistical significance of the p value (* p < 0.05, ** p < 0.01, *** p < 0.001)

Fig. 4

The Metacore™ apoptosis signaling pathway relating to caspase activation. Bars indicate the degree of up- or downregulation of the gene target relative to HUVEC cells; means decreased gene expression. means increased gene expression; height of bars corresponds to the change value. Numbers in symbols indicate: 1 LN18, 2 Daoy cell lines; number of asterisks reflects the statistical significance of the p value (* p < 0.05, ** p < 0.01, *** p < 0.001)