Whole-transcriptome sequencing profiling identifies functional and prognostic signatures in patients with PTPRZ1-MET fusion-negative secondary glioblastoma multiforme.

Gliomas are the most common type of primary brain tumor in adults with a high mortality rate. Low-grade gliomas progress to glioblastoma multiforme (GBM) in the majority of cases, forming secondary GBM (sGBM), followed by rapid fatal clinical outcomes. Protein tyrosine phosphatase receptor type Z1 (PTPRZ1)-MET proto-oncogene receptor tyrosine kinase (MET) (ZM) fusion has been identified as a biomarker for sGBM that is involved in glioma progression, but the mechanism of gliomagenesis and pathology of ZM-negative sGBM has remained to be fully elucidated. A whole-transcriptome signature is thus required to improve the outcome prediction for patients with sGBM without ZM fusion. In the present study, whole-transcriptome sequencing on 42 sGBM samples with or without ZM fusion from the Chinese Glioma Genome Atlas database identified mRNAs with differential expression between patients with and without ZM fusion and the most significant survival-associated genes were identified. A 6-gene signature was identified as a novel prognostic model reflecting survival probability in patients with ZM-negative sGBM. Clinical characteristics in patients with a high or low risk score value were analyzed with the Kaplan-Meier method and a two-sided log-rank test. In addition, ZM-negative sGBM patients with a high risk score exhibited an increase in immune cells, NF-κB-induced pathway activation and a decrease in endothelial cells compared with those with a low risk score. The present study demonstrated the potential use of a next-generation sequencing-based cancer gene signature in patients with ZM-negative sGBM, indicating possible clinical therapeutic strategies for further treatment of such patients.

Prognostic factors influencing clinical outcomes of glioblastoma multiforme.

BACKGROUND: Glioblastoma multiforme (GBM) is the most malignant kind of astrocytic tumors and is associated with a poor prognosis. In this retrospective study, we assessed the clinical, radiological, genetic molecular and treatment factors that influence clinical outcomes of patients with GBM. METHODS: A total of 116 patients with GBM who received surgery and radiation between January 2006 and December 2007 were included in this study. Kaplan-Meier survival analysis and Cox regression analysis were used to find the factors independently influencing patients' progression free survival (PFS) time and overall survival (OS) time. RESULTS: Age, preoperative Karnofsky Performance Scale (KPS) score, KPS score change at 2 weeks after operation, neurological deficit symptoms, tumor resection extent, maximal tumor diameter, involvement of eloquent cortex or deep structure, involvement of brain lobe, Ki-67 expression level and adjuvant chemotherapy were statistically significant factors (P < 0.05) for both PFS and OS in the univariate analysis. Cox proportional hazards modeling revealed that age or= 80, KPS score change after operation >or= 0, involvement of single frontal lobe, non-eloquent area or deep structure involvement, low Ki-67 expression and adjuvant chemotherapy were independent favorable factors (P < 0.05) for patients' clinical outcomes. CONCLUSIONS: Age at diagnosis, preoperative KPS score, KPS score change at 2 weeks postoperation, involvement of brain lobe, involvement of eloquent cortex or deep structure, Ki-67 expression level and adjuvant chemotherapy correlate significantly with the prognosis of patients with GBM.

Antiangiogenic therapy with bevacizumab in recurrent malignant gliomas: analysis of the response and core pathway aberrations.

BACKGROUND: Bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor, has shown promising activity in recurrent malignant gliomas. We reported the treatment response for the combination of bevacizumab and chemotherapy in a series of six patients with recurrent malignant glioma and investigated the molecular alterations in cancer pathways using the surgical biopsies from these patients. METHODS: Standard therapy with primary resection followed by adjuvant chemoradiotherapy had failed in all patients. Bevacizumab was administered at a dose of 10 mg/kg every 2 weeks. Concomitantly, four patients received temozolomide (50 mgxm(-2)xd(-1)), one patient irinotecan (125 mg/m(2) every 2 weeks) and one patient topotecan (1.2 mgxm(-2)xd(-1)). Response to therapy was mainly determined by magnetic resonance imaging. The expression of Ras, phosphorylated mitogen activated protein kinase (p-MAPK), phosphorylated AKT (p-AKT), phosphorylated mammalian target of rapamycin (p-mTOR) and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) were semiquantitatively assessed by immunohistochemistry using surgical biopsies before the initial treatment. RESULTS: Five of the six patients had a radiographic response. Three were complete response, and two were partial response. Only one patient had progressive disease. The 6-month progession-free survival (PFS) was 33% and the median PFS was 15 weeks, with a range of 6 to more than 60 weeks. Of the three core pathways analyzed in this study, the Ras/MAPK and phosphatidylinositol-3-kinase (PI3K)/AKT/mTOR pathways were more likely to be associated with the treatment response to bevacizumab. In two younger patients (ages < 50) with complete response, simultaneous overexpression of p-MAPK, p-AKT and p-mTOR might be the crucial feature. CONCLUSIONS: Bevacizumab in combination with chemotherapeutic agents may be an effective strategy for patients with recurrent malignant glioma. Activated MAPK and AKT might be possible biomarkers for selecting suitable patients for this targeted therapy.