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The prospective multicenter NOA-03 trial, conducted by the Neuro-Oncology Working Group (NOA) of the German Cancer Society, was initiated to define the feasibility and efficacy of single-agent high-dose methotrexate therapy without concomitant radiotherapy in immunocompetent patients with primary central nervous system lymphoma. Thirty-seven patients (median age, 60 years) received 179 biweekly courses of 8 g/m2 methotrexate. Response was assessed after 3 and 6 courses. We had planned to enter 105 patients into the trial. Since fewer than the projected 18 of 37 patients achieved a complete response after an intermediate analysis, the trial was closed. In intention-to-treat analysis, 11 of 37 patients (29.7%) achieved complete response, whereas 14 of 37 patients (37.8%) were found to have progressive disease. The median relapse-free survival among complete response patients was 13.7 months. Multivariate logistic regression analysis revealed that corticosteroid application during the first methotrexate course was associated with complete response. The regimen was well tolerated, but, unlike previously reported results, the activity of high-dose methotrexate was only moderate.

Radiotherapy is the single most effective therapy for malignant gliomas. Targeting the CD95 apoptotic pathway is a promising experimental approach to these neoplasms. Here, we asked whether irradiation modulates CD95-mediated apoptosis of human malignant glioma cells in vitro.LN-18, LN-229 and T98G human malignant glioma cell lines were irradiated with dosages from 0-8 Gy and treated with CD95L (CD95 ligand). CD95 expression was assessed by flow cytometry. Caspase activity was determined by DEVD cleavage. Cytotoxic effects were assessed by crystal violet staining of cells in a 96-well plate assay. Clonogenic cell death was determined by a standard colony forming assay.We find that (i) CD95L-induced apoptosis, but not irradiation-induced clonogenic cell death, involves caspase 3 activation and is blocked by the viral caspase inhibitor, crm-A. (ii) Irradiation does not modulate CD95 expression either in p53 wild-type or in p53 mutant glioma cell lines, and does not enhance CD95L-evoked caspase 3 activity or CD95L-induced clonogenic cell death.We conclude that endogenous CD95/CD95L interactions are not involved in radiation-induced clonogenic cell death and that the killing cascades of CD95L and irradiation are independent in human malignant glioma cells.

The differentiation state of early passage fibroblast cultures isolated from individual donors was quantified, identifying the differentiation state as a major determinant of the plating efficiency in vitro. After in vitro irradiation, terminal differentiation was the major pathway for inactivation of colony formation. The surviving population of progenitor fibroblasts displayed progression of the differentiation state, suggesting that surviving cells may be biologically 'aged'. The results show that a change in the ratio of precursor and functional cells towards terminally differentiated fibrocytes may play a central role in the induction of fibrosis of various organs.