40 research outputs found
Effect of the JAK2/STAT3 inhibitor SAR317461 on human glioblastoma tumorspheres
BackgroundThe STAT3 transcription factor is a major intracellular signaling protein and is frequently dysregulated in the most common and lethal brain malignancy in adults, glioblastoma multiforme (GBM). Activation of STAT3 in GBM correlates with malignancy and poor prognosis. The phosphorylating signal transducer JAK2 activates STAT3 in response to cytokines and growth factors. Currently there are no JAK-STAT pathway inhibitors in clinical trials for GBM, so we sought to examine the anti-GBM activity of SAR317461 (Sanofi-Aventis), a newer generation, highly potent JAK2 inhibitor that exhibits low toxicity and good pharmacokinetics. SAR317461 was initially approved for patient testing in the treatment of primary myelofibrosis (PMF), and has shown activity in preclinical models of melanoma and pulmonary cancer, but has not been tested in GBM.MethodsWe hypothesized that a potent small molecule JAK2 inhibitor could overcome the heterogeneous nature of GBM, and suppress a range of patient derived GBM tumorsphere lines and immortalized GBM cell lines. We treated with SAR317461 to determine IC50 values, and using Western blot analysis we asked whether the response was linked to STAT3 expression. Western blot analysis, FACS, and cell viability studies were used to identify the mechanism of SAR317461 induced cell death.ResultsWe report for the first time that the JAK2 inhibitor SAR317461 clearly inhibited STAT3 phosphorylation and had substantial activity against cells (IC50 1-10 µM) from 6 of 7 different patient GSC derived GBM tumorsphere lines and three immortalized GBM lines. One patient GSC derived line did not constitutively express STAT3 and was more resistant to SAR317461 (IC50 ≈25 µM). In terms of mechanism we found cleaved PARP and clear apoptosis following SAR317461. SAR317461 also induced autophagy and the addition of an autophagy inhibitor markedly enhanced cell killing by SAR317461.ConclusionsWe conclude that SAR317461 potently inhibits STAT3 phosphorylation and that it has significant activity against those GBM cells which express activated STAT3. Further studies are warranted in terms of the potential of SAR317461 as single and combined therapy for selectively treating human patients afflicted with GBMs expressing activation of the JAK2-STAT3 signaling axis
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miR-21 in the Extracellular Vesicles (EVs) of Cerebrospinal Fluid (CSF): A Platform for Glioblastoma Biomarker Development
Glioblastoma cells secrete extra-cellular vesicles (EVs) containing microRNAs (miRNAs). Analysis of these EV miRNAs in the bio-fluids of afflicted patients represents a potential platform for biomarker development. However, the analytic algorithm for quantitative assessment of EV miRNA remains under-developed. Here, we demonstrate that the reference transcripts commonly used for quantitative PCR (including GAPDH, 18S rRNA, and hsa-miR-103) were unreliable for assessing EV miRNA. In this context, we quantitated EV miRNA in absolute terms and normalized this value to the input EV number. Using this method, we examined the abundance of miR-21, a highly over-expressed miRNA in glioblastomas, in EVs. In a panel of glioblastoma cell lines, the cellular levels of miR-21 correlated with EV miR-21 levels (p<0.05), suggesting that glioblastoma cells actively secrete EVs containing miR-21. Consistent with this hypothesis, the CSF EV miR-21 levels of glioblastoma patients (n=13) were, on average, ten-fold higher than levels in EVs isolated from the CSF of non-oncologic patients (n=13, p<0.001). Notably, none of the glioblastoma CSF harbored EV miR-21 level below 0.25 copies per EV in this cohort. Using this cut-off value, we were able to prospectively distinguish CSF derived from glioblastoma and non-oncologic patients in an independent cohort of twenty-nine patients (Sensitivity=87%; Specificity=93%; AUC=0.91, p<0.01). Our results suggest that CSF EV miRNA analysis of miR-21 may serve as a platform for glioblastoma biomarker development
STUDI ALTERNATIF PERENCANAAAN SISTEM RANGKA PEMIKUL MOMEN KHUSUS (SRPMK) DENGAN KOLOM BULAT PADA KANTOR PUSAT ESTIKES KEPANJEN MALANG
Kolom merupakam elemen vertikal suatu struktur yang berfungsi menahan
beban aksial dan momen sebagai akibat beban gravitasi dan beban lateral yang
bekerja pada struktur. Oleh karena itu, kolom memegan penampang penting pada
keutuhan struktur, apabila kolom mengalami kegagalan akan berakibat pada
keruntuhan struktur bangunan atas gedung. perbedaan kolom bulat dan kolom
persegi sangkat mendasar. Jika ditinjau dari tulangan sengkang, kolom bulat
perpenampang spiral memiliki jarak sengkang yang berdekatan diabnding dengan
kolom dengan kolom persegi yang mempunya bentuk sengkang tunggal dan jarak
antara yang relatif besaar.
Kolom bulat yang menghasilkan kapsitas penampang, gaya – gaya dalam
seperti gaya aksial; gaya geser; gaya momen, dan simpangan (maximum
displacement) sehingga dalam skripsi ini untuk mengetahui desain kolom bulat
yang efisien dan efikas didalam perencanaan.
Hasil yang diperoleh dari perenanaan struktur gedung dengan kolom bulat
pada gedung kantor pusat stikes kepanjen malang dengan program bantu STAAD
PRO V 8, yang ditinjau dari kapasitas penampang dengan luas mutu beton kolom
bulat menghasilkan ØPn (aksial nominal) = 3988,690 kN, ØMn ( Momen nominal
) = 478,812 kNm, Vn (Geser nominal) = 681629,848 N. Sehingga kolom bulat
memiliki kapasitas penampang yang lebih besar dan efektif. Ditinjau dari rasio
dan gaya-gaya dalam struktur, kolom bulat memiliki gaya aksial = 0,021,
kekakuan struktur pada kolom bulat memiliki simpangan (maximum
displacements) yang lebih besar dari kolom persegi. Sehingga kekakuan pada
kolom bulat lebih tinggi dengan kolom persegi
Store-operated Ca2+ signaling in dendritic cells occurs independently of STIM1
STIM2-dependent SOCE signaling pathway in DCs may regulate Ca2+ levels at the immunological synapse
Traumatic brain injury and immunological outcomes: the double-edged killer
Traumatic brain injury (TBI) is a significant cause of mortality and morbidity worldwide resulting from falls, car accidents, sports, and blast injuries. TBI is characterized by severe, life-threatening consequences due to neuroinflammation in the brain. Contact and collision sports lead to higher disability and death rates among young adults. Unfortunately, no therapy or drug protocol currently addresses the complex pathophysiology of TBI, leading to the long-term chronic neuroinflammatory assaults. However, the immune response plays a crucial role in tissue-level injury repair. This review aims to provide a better understanding of TBI's immunobiology and management protocols from an immunopathological perspective. It further elaborates on the risk factors, disease outcomes, and preclinical studies to design precisely targeted interventions for enhancing TBI outcomes