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Abstract: Malignant gliomas are rapidly growing tumours that extensively invade the brain and have bad prognosis. Our study was performed to assess the metabolic effects of bevacizumab on the glioma cells carrying the IDH1 mutation, a mutation, associated with better prognosis and treatment outcome. Bevacizumab is known to inhibit tumour growth by neutralizing the biological activity of vascular endothelial growth factor (VEGF). However, the direct effects of bevacizumab on tumour cells metabolism remain poorly known. Materials and methods The immunoassay and MTT assay were used to assess the concentration of secreted VEGF and cell viability after bevacizumab exposure. Metabolomic studies on cells were performed using high resolution magic angle spinning spectroscopy (HRMAS). Results mIDH1-U87 cells secreted VEGF (13 ng/mL). Regardless, bevacizumab had no cytotoxic effect, even after a 72h exposure and with doses as high as 1 mg/mL. Yet, HRMAS analysis showed a significant effect of bevacizumab (0.1 mg/mL) on the metabolic phenotype of mIDH1-U87 cells with elevation of 2-hydroxyglutarate and changes in glutamine group metabolites (alanine, glutamate, glycine) and lipids (polyunsaturated fatty acids [PUFA], glycerophosphocholine, and phosphocholine). Conclusions In mIDH1-U87 cells, changes in glutamine group metabolites and lipids were identified as metabolic markers of bevacizumab treatment. These data support the possibility of a functional tricarboxylic acid cycle that runs in reductive manner, as a probable mechanism of action of bevacizumab in IDH1 mutated gliomas and propose a new target pathway for effective treatment of malignant gliomas.
Keywords: symptomatic pseudoprogression, atypical response, immunotherapy, lung cancer, idh1 mutation, malignant glioma, bevacizumab, metabolic fingerprint
Published in DiRROS: 11.06.2024; Views: 49; Downloads: 21
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Abstract: Treatment options of recurrent malignant gliomas are very limited and with a poor survival benefit. The results from phase II trials suggest that the combination of bevacizumab and irinotecan is beneficial. Patients and methods. The medical documentation of 19 adult patients with recurrent malignant gliomas was retrospectively reviewed. All patients received bevacizumab (10 mg/kg) and irinotecan (340 mg/m2 or 125 mg/m2) every two weeks. Patient clinical characteristics, drug toxicities, response rate, progression free survival (PFS) and overall survival (OS) were evaluated. Results. Between August 2008 and November 2011, 19 patients with recurrent malignant gliomas (median age 44.7, male 73.7%, WHO performance status 0%2) were treated with bevacizumab/irinotecan regimen. Thirteen patients had glioblastoma, 5 anaplastic astrocytoma and 1 anaplastic oligoastrocytoma. With exception of one patient, all patients had initially a standard therapy with primary resection followed by postoperative chemoradiotherapy. Radiological response was confirmed after 3 months in 9 patients (1 complete response, 8 partial responses), seven patients had stable disease and three patients have progressed. The median PFS was 6.8 months (95% confidence interval [CI]: 5.3-8.3) with six-month PFS rate 52.6%. The median OS was 7.7 months (95% CI: 6.6-8.7), while six-month and twelve-month survival rates were 68.4% and 31.6%, respectively. There were 16 cases of hematopoietic toxicity grade (G) 1-2. Non-hematopoietic toxicity was present in 14 cases, all G1-2, except for one patient with proteinuria G3. No grade 4 toxicities, no thromboembolic event and no intracranial hemorrhage were observed. Conclusions. In recurrent malignant gliomas combination of bevacizumab and irinotecan might be an active regimen with acceptable toxicity.
Keywords: recurrent malignant glioma, systemic therapy, bevacizumab
Published in DiRROS: 17.04.2024; Views: 183; Downloads: 48
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