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- Eriksson, Jonas, et al.
(författare)
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Synthesis of [3-N-11C-methyl]temozolomide via in situ activation of 3-N-hydroxymethyl temozolomide and alkylation with [11C]methyl iodide
- 2015
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Ingår i: Journal of labelled compounds & radiopharmaceuticals. - : Wiley. - 0362-4803 .- 1099-1344. ; 58:3, s. 122-126
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Tidskriftsartikel (refereegranskat)abstract
- Temozolomide is a chemotherapeutic drug that is mainly used in the treatment of primary glioblastoma multiforme and recurrent high-grade glioma. Here, we report an efficient good manufacturing practice compliant method for the synthesis of [3-N-11C-methyl]temozolomide from 3-N-hydroxymethyl temozolomide that cleaves off formaldehyde in situ and becomes activated towards alkylation with [11C]methyl iodide. The labelling method was developed for an on-going patient study in which the predictive value of [3-N-11C-methyl]temozolomide and positron emission tomography on the outcome of temozolomide treatment is being investigated. The precursor was reacted with [11C]methyl iodide in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene in acetonitrile, heated at stepwise increasing temperature. Purification by semipreparative HPLC with pharmaceutical grade eluent and filtration gave approximately 10 mL sterile product solution ready for injection containing 1.55 ± 0.38 GBq (n = 5), the specific activity was 88 ± 25 GBq/μmol and the radiochemical purity was 98.5 ± 1.9%.13C-NMR spectroscopy confirmed the labelled position after colabelling with 11C and 13C.
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| 2. |
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| 3. |
- Best, Myron G., et al.
(författare)
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RNA-Seq of Tumor-Educated Platelets Enables Blood-Based Pan-Cancer, Multiclass, and Molecular Pathway Cancer Diagnostics
- 2015
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Ingår i: Cancer Cell. - : Elsevier BV. - 1535-6108 .- 1878-3686. ; 28:5, s. 666-676
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Tidskriftsartikel (refereegranskat)abstract
- Tumor-educated blood platelets (TEPs) are implicated as central players in the systemic and local responses to tumor growth, thereby altering their RNA profile. We determined the diagnostic potential of TEPs by mRNA sequencing of 283 platelet samples. We distinguished 228 patients with localized and metastasized tumors from 55 healthy individuals with 96% accuracy. Across six different tumor types, the location of the primary tumor was correctly identified with 71% accuracy. Also, MET or HER2-positive, and mutant KRAS, EGFR, or PIK3CA tumors were accurately distinguished using surrogate TEP mRNA profiles. Our results indicate that blood platelets provide a valuable platform for pan-cancer, multiclass cancer, and companion diagnostics, possibly enabling clinical advances in blood-based "liquid biopsies".
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| 4. |
- van Thuijl, Hinke F., et al.
(författare)
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Evolution of DNA repair defects during malignant progression of low-grade gliomas after temozolomide treatment
- 2015
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Ingår i: Acta Neuropathologica. - : Springer Verlag (Germany). - 0001-6322 .- 1432-0533. ; 129:4, s. 597-607
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Tidskriftsartikel (refereegranskat)abstract
- Temozolomide (TMZ) increases the overall survival of patients with glioblastoma (GBM), but its role in the clinical management of diffuse low-grade gliomas (LGG) is still being defined. DNA hypermethylation of the O (6) -methylguanine-DNA methyltransferase (MGMT) promoter is associated with an improved response to TMZ treatment, while inactivation of the DNA mismatch repair (MMR) pathway is associated with therapeutic resistance and TMZ-induced mutagenesis. We previously demonstrated that TMZ treatment of LGG induces driver mutations in the RB and AKT-mTOR pathways, which may drive malignant progression to secondary GBM. To better understand the mechanisms underlying TMZ-induced mutagenesis and malignant progression, we explored the evolution of MGMT methylation and genetic alterations affecting MMR genes in a cohort of 34 treatment-na less than ve LGGs and their recurrences. Recurrences with TMZ-associated hypermutation had increased MGMT methylation compared to their untreated initial tumors and higher overall MGMT methylation compared to TMZ-treated non-hypermutated recurrences. A TMZ-associated mutation in one or more MMR genes was observed in five out of six TMZ-treated hypermutated recurrences. In two cases, pre-existing heterozygous deletions encompassing MGMT, or an MMR gene, were followed by TMZ-associated mutations in one of the genes of interest. These results suggest that tumor cells with methylated MGMT may undergo positive selection during TMZ treatment in the context of MMR deficiency.
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