| 1. |
- Sooman, Linda, et al.
(författare)
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FGF2 as a potential prognostic biomarker for proneural glioma patients
- 2015
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Ingår i: Acta Oncologica. - : Informa Healthcare. - 0284-186X .- 1651-226X. ; 54:3, s. 385-394
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The survival of high-grade glioma patients is poor and the treatment of these patients can cause severe side effects. This fosters the necessity to identify prognostic biomarkers, in order to optimize treatment and diminish unnecessary suffering of patients. The aim of this study was to identify prognostic biomarkers for high-grade glioma patients. METHODS: Eleven proteins were selected for analysis due to their suggested importance for survival of patients with other types of cancers and due to a high variation in protein levels between glioma patients (according to the Human Protein Atlas, www.proteinatlas.org). Protein expression patterns of these 11 proteins were analyzed by immunohistochemistry in tumor samples from 97 high-grade glioma patients. The prognostic values of the proteins were analyzed with univariate and multivariate Cox regression analyses for the high-grade glioma patients, including subgroup analyses of histological subtypes and immunohistochemically defined molecular subtypes. RESULTS: The proteins with the most significant (univariate and multivariate p<0.05) correlations were analyzed further with cross-validated Kaplan-Meier analyses for the possibility of predicting survival based on the protein expression pattern of the corresponding candidate. Random Forest classification with variable subset selection was used to analyze if a protein signature consisting of any combination of the 11 proteins could predict survival for the high-grade glioma patients and the subgroup with glioblastoma patients. The proteins which correlated most significantly (univariate and multivariate p<0.05) to survival in the Cox regression analyses were Myc for all high-grade gliomas and FGF2, CA9 and CD44 for the subgroup of proneural gliomas, with FGF2 having a strong negative predictive value for survival. No prognostic signature of the proteins could be found. CONCLUSION: FGF2 is a potential prognostic biomarker for proneural glioma patients, and warrants further investigation.
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| 2. |
- Sooman, Linda, et al.
(författare)
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PTPN6 expression is epigenetically regulated and influences survival and response to chemotherapy in high-grade gliomas
- 2014
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Ingår i: Tumor Biology. - : Springer Science and Business Media LLC. - 1010-4283 .- 1423-0380. ; 35:5, s. 4479-4488
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Tidskriftsartikel (refereegranskat)abstract
- The prognosis of high-grade glioma patients is poor, and the tumors are characterized by resistance to therapy. The aims of this study were to analyze the prognostic value of the expression of the protein tyrosine phosphatase non-receptor type 6 (PTPN6, also referred to as SHP1) in high-grade glioma patients, the epigenetic regulation of the expression of PTPN6, and the role of its expression in chemotherapy resistance in glioma-derived cells. PTPN6 expression was analyzed with immunohistochemistry in 89 high-grade glioma patients. Correlation between PTPN6 expression and overall survival was analyzed with Kaplan-Meier univariate analysis and Cox regression multivariate analysis. Differences in drug sensitivity to a panel of 16 chemotherapeutic drugs between PTPN6-overexpressing clones and control clones were analyzed in vitro with the fluorometric microculture cytotoxicity assay. Cell cycle analysis was done with Krishan staining and flow cytometry. Apoptosis was analyzed with a cell death detection ELISA kit as well as cleaved caspase-3 and caspase-9 Western blotting. Autophagy was analyzed with LC3B Western blotting. Methylation of the PTPN6 promoter was analyzed with bisulfite pyrosequencing, and demethylation of PTPN6 was done with decitabine treatment. The PTPN6 expression correlated in univariate analysis to poor survival for anaplastic glioma patients (p = 0.026). In glioma-derived cell lines, overexpression of PTPN6 caused increase resistance (p < 0.05) to the chemotherapeutic drugs bortezomib, cisplatin, and melphalan. PTPN6 expression did not affect bortezomib-induced cell cycle arrest, apoptosis, or autophagy. Low PTPN6 promoter methylation correlated to protein expression, and the protein expression was increased upon demethylation in glioma-derived cells. PTPN6 expression may be a factor contributing to poor survival for anaplastic glioma patients, and in glioma-derived cells, its expression is epigenetically regulated and influences the response to chemotherapy.
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| 3. |
- Sooman, Linda, et al.
(författare)
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Vandetanib combined with a p38 MAPK inhibitor synergistically reduces glioblastoma cell survival
- 2013
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Ingår i: Medical Oncology. - : Springer Science and Business Media LLC. - 1357-0560 .- 1559-131X. ; 30:3, s. 638-
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Tidskriftsartikel (refereegranskat)abstract
- The survival for patients with high-grade glioma is poor, and only a limited number of patients respond to the therapy. The aim of this study was to analyze the significance of using p38 MAPK phosphorylation as a prognostic marker in high-grade glioma patients and as a therapeutic target in combination chemotherapy with vandetanib. p38 MAPK phosphorylation was analyzed with immunohistochemistry in 90 high-grade glioma patients. Correlation between p38 MAPK phosphorylation and overall survival was analyzed with Mann-Whitney U test analysis. The effects on survival of glioblastoma cells of combining vandetanib with the p38 MAPK inhibitor SB 203580 were analyzed in vitro with the median-effect method with the fluorometric microculture cytotoxicity assay. Two patients had phosphorylated p38 MAPK in both the cytoplasm and nucleus, and these two presented with worse survival than patients with no detectable p38 MAPK phosphorylation or phosphorylated p38 MAPK only in the nucleus. This was true for both high-grade glioma patients (WHO grade III and IV, n = 90, difference in median survival: 6.1 months, 95 % CI [0.20, 23], p = 0.039) and for the subgroup with glioblastoma patients (WHO grade IV, n = 70, difference in median survival: 6.1 months, 95 % CI [0.066, 23], p = 0.043). The combination of vandetanib and the p38 MAPK inhibitor SB 203580 had synergistic effects on cell survival for glioblastoma-derived cells in vitro. In conclusion, p38 MAPK phosphorylation may be a prognostic marker for high-grade glioma patients, and vandetanib combined with a p38 MAPK inhibitor may be useful combination chemotherapy for glioma patients.
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