scholarly journals Aberrant signaling pathways in medulloblastomas: a stem cell connection

2010 ◽  
Vol 68 (6) ◽  
pp. 947-952 ◽  
Author(s):  
Carolina Oliveira Rodini ◽  
Daniela Emi Suzuki ◽  
Adriana Miti Nakahata ◽  
Márcia Cristina Leite Pereira ◽  
Luciana Janjoppi ◽  
...  

Medulloblastoma is a highly malignant primary tumor of the central nervous system. It represents the most frequent type of solid tumor and the leading cause of death related to cancer in early childhood. Current treatment includes surgery, chemotherapy and radiotherapy which may lead to severe cognitive impairment and secondary brain tumors. New perspectives for therapeutic development have emerged with the identification of stem-like cells displaying high tumorigenic potential and increased radio- and chemo-resistance in gliomas. Under the cancer stem cell hypothesis, transformation of neural stem cells and/or granular neuron progenitors of the cerebellum are though to be involved in medulloblastoma development. Dissecting the genetic and molecular alterations associated with this process should significantly impact both basic and applied cancer research. Based on cumulative evidences in the fields of genetics and molecular biology of medulloblastomas, we discuss the possible involvement of developmental signaling pathways as critical biochemical switches determining normal neurogenesis or tumorigenesis. From the clinical viewpoint, modulation of signaling pathways such as TGFβ, regulating neural stem cell proliferation and tumor development, might be attempted as an alternative strategy for future drug development aiming at more efficient therapies and improved clinical outcome of patients with pediatric brain cancers.

2020 ◽  
Vol 64 (3) ◽  
pp. 485-499
Author(s):  
Aruna Kilaru ◽  
Kent D. Chapman

Abstract Thirty years ago, the discovery of a cannabinoid (CB) receptor that interacts with the psychoactive compound in Cannabis led to the identification of anandamide, an endogenous receptor ligand or endocannabinoid. Research on endocannabinoids has since exploded, and additional receptors along with their lipid mediators and signaling pathways continue to be revealed. Specifically, in humans, the release of endocannabinoids from membrane lipids occurs on demand and the signaling process is rapidly attenuated by the breakdown of the ligand suggesting a tight regulation of the endocannabinoid system (ECS). Additionally, the varying distribution of CB receptors between the central nervous system and other tissues allows for the ECS to participate in a wide range of cognitive and physiological processes. Select plant-derived ‘phyto’cannabinoids such as Δ-9-tetrahydrocannabinol (Δ9-THC) bind to the CB receptors and trigger the ECS, and in the case of Δ9-THC, while it has therapeutic value, can also produce detrimental effects. Current research is aimed at the identification of additional phytocannabinoids with minimal psychotropic effects with potential for therapeutic development. Although decades of research on the ECS and its components have expanded our understanding of the mechanisms and implications of endocannabinoid signaling in mammals, it continues to evolve. Here, we provide a brief overview of the ECS and its overlap with other related lipid-mediated signaling pathways.


2021 ◽  
Vol 11 (4) ◽  
pp. 1941
Author(s):  
Seungmin Yeom ◽  
Myung Chul Lee ◽  
Shambhavi Pandey ◽  
Jaewoon Lim ◽  
Sangbae Park ◽  
...  

Induced pluripotent stem cells (iPSCs) are a good medicine source because of their potential to differentiate into various tissues or cells. However, traditionally, iPSCs made by specific transgenes and virus vectors are not appropriate for clinical use because of safety concerns and risk of tumor development. The goal of this research was to develop an alternative method for reprogramming, using small molecules and external stimuli. Two groups were established: short-term shear stress (STSS) under suspension culture and a combination of short-term shear stress and vitamin C (SSVC) under suspension culture. For STSS, the pipetting was carried out for cells twice per day for 2 min for 14 days in the embryonic stem cell (ES) medium. In the case of SSVC, the procedure was the same as for STSS however, its ES medium included 10 µM of vitamin C. After 14 days, all spheroids were picked and checked for pluripotency by ALP (alkaline phosphatase) assay and immunocytochemistry. Both groups partially showed the characteristics of stem cells but data demonstrated that the spheroids under shear stress and vitamin C had improved stem cell-like properties. This research showed the possibility of external stimuli and small molecules to reprogram the somatic cells without the use of transgenes.


Author(s):  
Shun-Fat Lau ◽  
Amy K. Y. Fu ◽  
Nancy Y. Ip

AbstractGenetic analyses have revealed the pivotal contribution of microglial dysfunctions to the pathogenesis of Alzheimer’s disease (AD). Along AD progression, the accumulation of danger-associated molecular patterns (DAMPs) including beta-amyloid and hyperphosphorylated tau continuously stimulates microglia, which results in their chronic activation. Chronically activated microglia secrete excessive pro-inflammatory cytokines, which further regulate microglial responses towards DAMPs. This has spurred longstanding interest in targeting cytokine-induced microglial responses for AD therapeutic development. However, the cytokine-induced microglial state transition is not comprehensively understood. Cytokines are assumed to induce microglial state transition from a resting state to an activated state. However, recent evidence indicate that this microglial state transition involves multiple sequential functional states. Moreover, the mechanisms by which different functional states within the cytokine-induced microglial state transition regulate AD pathology remain unclear. In this review, we summarize how different cytokine signaling pathways, including those of IL-33 (interleukin-33), NLRP3 inflammasome–IL-1β, IL-10, and IL-12/IL-23, regulate microglial functions in AD. Furthermore, we discuss how the modulation of these cytokine signaling pathways can result in beneficial outcomes in AD. Finally, we describe a stepwise functional state transition of microglia induced by cytokine signaling that can provide insights into the molecular basis of the beneficial effects of cytokine modulation in AD and potentially aid therapeutic development.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii415-iii415
Author(s):  
Claire Sun ◽  
Caroline Drinkwater ◽  
Dhanya Sooraj ◽  
Gabrielle Bradshaw ◽  
Claire Shi ◽  
...  

Abstract The precise decoding of human genomes facilitated by the advancements in next-generation sequencing has led to a better understanding of genetic underpinnings of pediatric brain cancers. Indeed, it is now evident that tumours of the same type harbour distinct driving mutations and molecular aberrations that can result in different prognosis and treatment outcomes. The profounder insight into the the identity, amount and types of molecular aberrations has paved the way for the advent of targeted therapies in precision medicine. Nevertheless, less than 10% of pediatric cancer patients harbour actionable mutations. Strictly limited therapeutic options that are firstly available for brain cancers and secondly acceptable for children’s development further impede the breakthrough in the survival rate in pediatric brain cancers. This underscores a desperate need to delve beyond genomic sequencing to identify biomarker coupled therapies that not only featured with treatment efficacy in the central nervous system but also acceptable side effects for children. The Hudson-Monash Paediatric Precision Medicine (HMPPM) Program focuses on utilising genetic profiles of patients’ tumour models to identify new therapeutic targets and repurpose existing ones using high-throughput functional genomics screens (2220 drugs and CRISPR screen of 300 oncogenic genes). Using a large compendium of over sixty patient derived paediatric brain cancer models, we provide proof-of-concept data that shows an integrative pipeline for functional genomics with multi-omics datasets to perform genotype-phenotype correlations and, therefore, identify genetic dependencies. Herein, using several examples in ATRT, DIPG and HGG, we show how functional interrogations can better define molecular subclassification of tumours and identify unique vulnerabilities.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Eduard H. Panosyan ◽  
Alan K. Ikeda ◽  
Vivian Y. Chang ◽  
Dan R. Laks ◽  
Charles L. Reeb ◽  
...  

Background. Dose-dependent response makes certain pediatric brain tumors appropriate targets for high-dose chemotherapy with autologous hematopoietic stem-cell rescue (HDCT-AHSCR).Methods. The clinical outcomes and toxicities were analyzed retrospectively for 18 consecutive patients ≤19 y/o treated with HDCT-AHSCR at UCLA (1999–2009).Results. Patients' median age was 2.3 years. Fourteen had primary and 4 recurrent tumors: 12 neural/embryonal (7 medulloblastomas, 4 primitive neuroectodermal tumors, and a pineoblastoma), 3 glial/mixed, and 3 germ cell tumors. Eight patients had initial gross-total and seven subtotal resections. HDCT mostly consisted of carboplatin and/or thiotepa ± etoposide (n=16). Nine patients underwent a single AHSCR and nine ≥3 tandems. Three-year progression-free and overall survival probabilities were 60.5% ± 16 and 69.3% ± 11.5. Ten patients with pre-AHSCR complete remissions were alive/disease-free, whereas 5 of 8 with measurable disease were deceased (median followup: 2.3 yrs). Nine of 13 survivors avoided radiation. Single AHSCR regimens had greater toxicity than ≥3 AHSCR (P<.01).Conclusion. HDCT-AHSCR has a definitive, though limited role for selected pediatric brain tumors with poor prognosis and pretransplant complete/partial remissions.


Blood ◽  
2006 ◽  
Vol 108 (12) ◽  
pp. 3906-3912 ◽  
Author(s):  
Jorg A. Kruger ◽  
Charles D. Kaplan ◽  
Yunping Luo ◽  
He Zhou ◽  
Dorothy Markowitz ◽  
...  

AbstractRecently, the cancer stem cell hypothesis has gained significant recognition as the descriptor of tumorigenesis. Although previous studies relied on transplanting human or rat tumor cells into immunecompromised mice, our study used the Hoechst 33342 dye–based side population (SP) technique to isolate and transplant stem cell–like cancer cells (SCLCCs) from the 4T1 and NXS2 murine carcinoma cell lines into the immune-competent microenvironment of syngeneic mice. 4T1 cells displayed an SP of 2% with a Sca-1highc-Kit–CD45– phenotype, whereas NXS2 cells contained an SP of 0.2% with a Sca-1highCD24highc-Kit–CD45–GD high2 phenotype. Reverse transcription–polymerase chain reaction (RT-PCR) further revealed up-regulation in SP cells of ABCG2, Sca-1, Wnt-1, and TGF-β2. Additionally, 4T1 and NXS2 SP cells exhibited increased resistance to chemotherapy, and 4T1 SP cells also showed an increased ability to efflux doxorubicin, which correlated with a selective increase in the percentage of SP cells found in the tumors of doxorubicin-treated mice. Most importantly, SP cells showed a markedly higher repopulation and tumorigenic potential in vivo, which correlated with an increased number of cells in the SP compartment of SP-derived tumors. Taken together, these results show that we successfully characterized SCLCCs from 2 murine carcinoma cell lines in the immune-competent microenvironment of syngeneic mice.


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