Prognostic Associations of Activated Mitogen-Activated Protein Kinase and Akt Pathways in Glioblastoma

• Published in: Clinical cancer research Vol. 12; no. 13; pp. 3935 - 3941
• Main Authors: Pelloski, Christopher E, Lin, E, Zhang, Li, Yung, W K Alfred, Colman, Howard, Liu, Juinn-Lin, Woo, Shaio Y, Heimberger, Amy B, Suki, Dima, Prados, Michael, Chang, Susan, Barker, 3rd, Fredrick G, Fuller, Gregory N, Aldape, Kenneth D
• Format: Journal Article
• Language: English
• Published: United States American Association for Cancer Research 01.07.2006
• Subjects: Adipokines; Adolescent; Adult; Aged; Aged, 80 and over; Chitinase-3-Like Protein 1; Cohort Studies; Follow-Up Studies; Glioblastoma - diagnosis; Glioblastoma - metabolism; Glioblastoma - therapy; Glioma; Glycoproteins - biosynthesis; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Lectins; Middle Aged; Mitogen-Activated Protein Kinases - biosynthesis; Mitogen-Activated Protein Kinases - metabolism; Phosphorylation; Predictive Value of Tests; Prognosis; prognostic marker; Protein Kinases - biosynthesis; Proto-Oncogene Proteins c-akt - biosynthesis; Proto-Oncogene Proteins c-akt - metabolism; Retrospective Studies; Ribosomal Protein S6 Kinases, 70-kDa - biosynthesis; Signal Transduction; Survival Rate; TOR Serine-Threonine Kinases; Treatment Outcome
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.CCR-05-2202

Purpose: Activation of mitogen-activated protein kinase (MAPK) and members of the Akt pathway have been shown to promote cell proliferation, survival, and resistance to radiation. This study was conducted to determine whether any of these markers are associated with survival time and response to radiation in glioblastoma. Experimental Design: The expression of phosphorylated (p-)Akt, mammalian target of rapamycin (p-mTOR), p-p70S6K, and p-MAPK were assessed by immunohistochemical staining in 268 cases of newly diagnosed glioblastoma. YKL-40, a prognostic marker previously examined in these tumors, was also included in the analysis. Expression data were tested for correlations with response to radiation therapy in 131 subtotally resected cases and overall survival (in all cases). Results were validated in an analysis of 60 patients enrolled in clinical trials at a second institution. Results: Elevated p-MAPK expression was most strongly associated with poor response to radiotherapy, a finding corroborated in the validation cohort. For survival, higher expressions of p-mTOR, p-p70S6K, and p-MAPK were associated with worse outcome (all P < 0.03). YKL-40 expression was associated with the expressions of p-MAPK, p-mTOR, and p-p70S6K (all P < 0.02), with a trend toward association with p-Akt expression ( P = 0.095). When known clinical variables were added to a multivariate analysis, only age, Karnofsky performance score, and p-MAPK expression emerged as independent prognostic factors. Conclusions: p-MAPK and activated members of the Akt pathway are markers of outcome in glioblastoma. Elevated expression of p-MAPK is associated with increased radiation resistance and represents an independent prognostic factor in these tumors.