Glioma-initiating cells (GIC) are considered the underlying cause of recurrences of aggressive glioblastomas, replenishing the tumor population and undermining the efficacy of conventional chemotherapy. Here we report the discovery that inhibiting T-type voltage-gated Ca and K channels can effectively induce selective cell death of GIC and increase host survival in an orthotopic mouse model of human glioma. At present, the precise cellular pathways affected by the drugs affecting these channels are unknown. However, using cell-based assays and integrated proteomics, phosphoproteomics, and transcriptomics analyses, we identified the downstream signaling events these drugs affect. Changes in plasma membrane depolarization and elevated intracellular Na, which compromised Na-dependent nutrient transport, were documented. Deficits in nutrient deficit acted in turn to trigger the unfolded protein response and the amino acid response, leading ultimately to nutrient starvation and GIC cell death. Our results suggest new therapeutic targets to attack aggressive gliomas. .

BackgroundLittle is known about the role of glial host cells in brain tumours. However, supporting stromal cells have been shown to foster tumour growth in other cancers.MethodsWe isolated stromal cells from patient-derived glioblastoma (GBM) xenografts established in GFP-NOD/scid mice. With simultaneous removal of CD11b+ immune and CD31+ endothelial cells by fluorescence activated cell sorting (FACS), we obtained a population of tumour-associated glial cells, TAGs, expressing markers of terminally differentiaed glial cell types or glial progenitors. This cell population was subsequently characterised using gene expression analyses and immunocytochemistry. Furthermore, sphere formation was assessed in vitro and their glioma growth-promoting ability was examined in vivo. Finally, the expression of TAG related markers was validated in human GBMs.ResultsTAGs were highly enriched for the expression of glial cell proteins including GFAP and myelin basic protein (MBP), and immature markers such as Nestin and O4. A fraction of TAGs displayed sphere formation in stem cell medium. Moreover, TAGs promoted brain tumour growth in vivo when co-implanted with glioma cells, compared to implanting only glioma cells, or glioma cells and unconditioned glial cells from mice without tumours. Genome-wide microarray analysis of TAGs showed an expression profile distinct from glial cells from healthy mice brains. Notably, TAGs upregulated genes associated with immature cell types and self-renewal, including Pou3f2 and Sox2. In addition, TAGs from highly angiogenic tumours showed upregulation of angiogenic factors, including Vegf and Angiopoietin 2. Immunohistochemistry of three GBMs, two patient biopsies and one GBM xenograft, confirmed that the expression of these genes was mainly confined to TAGs in the tumour bed. Furthermore, their expression profiles displayed a significant overlap with gene clusters defining prognostic subclasses of human GBMs.ConclusionsOur data demonstrate that glial host cells in brain tumours are functionally distinct from glial cells of healthy mice brains. Furthermore, TAGs display a gene expression profile with enrichment for genes related to stem cells, immature cell types and developmental processes. Future studies are needed to delineate the biological mechanisms regulating the brain tumour-host interplay.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-017-3109-8) contains supplementary material, which is available to authorized users.

Tutum Ölçeği kullanılmıştır. Ölçek kullanımı için Vefikuluçay'dan yazılı onay alınmıştır. Verilerin analizinde ise t-testi ve varyans analizi kullanıldı. Ayrıca Kişisel Bilgi Formu ile elde edilen bilgiler yüzde ve frekans olarak verildi. Araştırmanın sonucunda, kadın öğrencilerin erkek öğrencilere göre ve Sağlık Bilimleri Fakültesi öğrencilerinin diğer öğrencilere göre yaşlı bireylere yönelik daha olumlu tutumlara sahip olduğu saptandı. Ayrıca, ailede yaşlı bir bireyin olması, evde yaşlı bir bireyle birlikte yaşama ve yaşlı bireylerle yüksek oranda karşılaşma sıklığına sahip olma gibi yaşlılarla birlikteliği arttıran özelliklerin de olumlu tutumları arttırdığı belirlendi.Araştırma puanlarına bakılarak yaşlılara yönelik olumsuz tutum puanlarında en yüksek puanlara sahip gruplar üzerinde araştırmalar yapılabilir.

Here we describe a NOD/Scid mouse strain expressing the dsRed transgene. The strain is maintained by inbreeding of homozygous dsRed NOD/Scid siblings, and expresses red fluorescence from various organs. The model allows engraftment of human tumor tissue, and engrafted tumors were separated into stromal and malignant cell compartments. Furthermore, we compared tumor-associated and normal fibroblast for expression of fibroblast-associated markers, and identified a marker panel that was upregulated in the tumor-associated fibroblasts. In conclusion, we propose that this model may be used in a variety of studies of tumor progression and to elucidate the role of the tumor microenvironment.

The neurodevelopmental transcription factor POU3F2 (also called OCT7 / BRN2) is expressed during neurogenesis. Moreover, POU3F2 expression has been reported as a promoter of proliferation and invasion in malignant melanoma of the skin. Since both melanomas and CNS-malignancies arise in organs of neuro-ectodermal origin, we investigated whether human gliomas expressed POU3F2 and the role of POU3F2 in glioma tumorigenesis. We performed immunohistochemistry of 149 grade II-IV gliomas from our tumor bank, and subsequently performed western blots and qPCR of 12 samples from each grade. In addition, we performed flow cytometric analysis of POU3F2 expression in 5 acutely dissociated tumors. Using lentiviral transfection we established glioma cell lines with POU3F2 overexpression or knock down in order the to investigate the effect of POU3F2 on proliferation, migration and differentiation, both in vitro and in vivo. The mechanism, by which POU3F2 regulates glioma progression, was also investigated. Immunohistochemistry showed that POU3F2 was almost uniformly expressed in human gliomas. Both western blot, qPCR and flow cytometry confirmed expression of POU3F2 in human gliomas. In acutely dissociated tumors, the POU3F2 positive cells displayed an increased cell percentage in the S and G2/M phase of the cell cycle. Moreover, POU3F2 overexpression in the glioma cell lines increased growth rates and colony formation. Overexpression of POU3F2 increased the levels of phosphorylated p-44/42 indicating activation of the ERK1/2 signaling pathway. Increased levels of downstream transcriptional targets c-Myc, Elk1 and Stat3 transcription factors in the POU3F2 overexpressing cell lines confirmed activation of the MAPK signaling pathway. Furthermore, the POU3F2 overexpressing cell lines displayed increased expression of the growth factor FGF2. U0126, an inhibitor of MEK1/2, decreased the cell proliferation and decrease levels of phospho-p44/42, phospho-stat3 and FGF2. Moreover, overexpression of the POU3F2 increases the level of other neurodevelopmental transcription factors associated with a pluripotent state. Ongoing studies aim at further elucidating the multiple roles of POU3F2 in brain tumor progression. Citation Format: Mohummad Aminur Rahman, Lina Liess, Mohammad S. Lellahi, Christiane H. Gjerde, Halala S. Saed, Ercan Mutlu, Huaiyang Zhu, Jian Wang, Per Øyvind Enger. The transcription factor POU3F2 is expressed in human gliomas and promotes tumorigenesis in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2101. doi:10.1158/1538-7445.AM2015-2101