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Leptomeningeal dissemination of a primary brain tumor is a condition which is challenging to treat, as it often occurs in rather late disease stages in highly pretreated patients. Its prognosis is dismal and there is still no accepted standard of care. We report here a good clinical effect with a partial response in three out of nine patients and a stable disease with improvement on symptoms in two more patients following systemic anti-angiogenic treatment with bevacizumab (BEV) alone or in combination with chemo- and/or radiotherapy in a series of patients with leptomeningeal dissemination from primary brain tumors (diffuse astrocytoma WHO°II, anaplastic astrocytoma WHO°III, anaplastic oligodendroglioma WHO°III, primitive neuroectodermal tumor and glioblastoma, both WHO°IV). This translated into effective symptom control in five out of nine patients, but only moderate progression-free and overall survival times were reached. Partial responses as assessed by RANO criteria were observed in three patients (each one with anaplastic oligodendroglioma, primitive neuroectodermal tumor and glioblastoma). In these patients progression-free survival (PFS) intervals of 17, 10 and 20 weeks were achieved. In three patients (each one with diffuse astrocytoma, anaplastic astrocytoma and primitive neuroectodermal tumor) stable disease was observed with PFS of 13, 30 and 8 weeks. Another three patients (all with glioblastoma) were primary non-responders and deteriorated rapidly with PFS of 3 to 4 weeks. No severe adverse events were seen. These experiences suggest that the combination of BEV with more conventional therapy schemes with chemo- and/or radiotherapy may be a palliative treatment option for patients with leptomeningeal dissemination of brain tumors.
Recently, the conserved intracellular digestion mechanism ‘autophagy’ has been considered to be involved in early tumorigenesis and its blockade proposed as an alternative treatment approach. However, there is an ongoing debate about whether blocking autophagy has positive or negative effects in tumor cells. Since there is only poor data about the clinico-pathological relevance of autophagy in gliomas in vivo, we first established a cell culture based platform for the in vivo detection of the autophago-lysosomal components. We then investigated key autophagosomal (LC3B, p62, BAG3, Beclin1) and lysosomal (CTSB, LAMP2) molecules in 350 gliomas using immunohistochemistry, immunofluorescence, immunoblotting and qPCR. Autophagy was induced pharmacologically or by altering oxygen and nutrient levels. Our results show that autophagy is enhanced in astrocytomas as compared to normal CNS tissue, but largely independent from the WHO grade and patient survival. A strong upregulation of LC3B, p62, LAMP2 and CTSB was detected in perinecrotic areas in glioblastomas suggesting micro-environmental changes as a driver of autophagy induction in gliomas. Furthermore, glucose restriction induced autophagy in a concentration-dependent manner while hypoxia or amino acid starvation had considerably lesser effects. Apoptosis and autophagy were separately induced in glioma cells both in vitro and in vivo. In conclusion, our findings indicate that autophagy in gliomas is rather driven by micro-environmental changes than by primary glioma-intrinsic features thus challenging the concept of exploitation of the autophago-lysosomal network (ALN) as a treatment approach in gliomas.