86 research outputs found
Tridimensional Retinoblastoma Cultures as Vitreous Seeds Models for Live-Cell Imaging of Chemotherapy Penetration
A preclinical model could aid in understanding retinoblastoma vitreous seeds behavior, drug penetration, and response to chemotherapy to optimize patient treatment. Our aim was to develop a tridimensional in vitro model of retinoblastoma vitreous seeds to assess chemotherapy penetration by means of live-cell imaging. Cell cultures from patients with retinoblastoma who underwent upfront enucleation were established and thoroughly characterized for authentication of human tumor origin. The correlation of the in vitro tridimensional structures resembling human spheres and dusts vitreous seeds was established. Confocal microscopy was used to quantify real-time fluorescence of topotecan as a measure of its penetration into different sizes of spheres. Cell viability was determined after chemotherapy penetration. The in vitro spheres and dusts models were able to recapitulate the morphology, phenotype, and genotype of patient vitreous seeds. The larger the size of the spheres, the longer the time required for the drug to fully penetrate into the core (p < 0.05). Importantly, topotecan penetration correlated with its cytotoxic activity. Therefore, the studied tridimensional cell model recapitulated several characteristics of vitreous seeds observed in patients with retinoblastoma and were successfully used to assess live-cell imaging of chemotherapy penetration for drug distribution studies.Fil: Winter, Ursula Andrea. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂa "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Aschero, MarĂa del Rosario. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂa "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Fuentes, Federico. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Buontempo, Fabian. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂa "Juan P. Garrahan"; ArgentinaFil: Zugbi, Santiago. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂa "Juan P. Garrahan"; ArgentinaFil: Sgroi, Mariana. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂa "Juan P. Garrahan"; ArgentinaFil: Sampor, Claudia. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂa "Juan P. Garrahan"; ArgentinaFil: Abramson, David H.. Memorial Sloan-kettering Cancer Center; Estados UnidosFil: Carcaboso, Angel M.. Hospital Sant Joan de Deu Barcelona; EspañaFil: Schaiquevich, Paula Susana. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂa "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Neural crest-related NXPH1/α-NRXN signaling opposes neuroblastoma malignancy by inhibiting organotropic metastasis
Neuroblastoma is a pediatric cancer that can present as low- or high-risk tumors (LR-NBs and HR-NBs), the latter group showing poor prognosis due to metastasis and strong resistance to current therapy. Whether LR-NBs and HR-NBs differ in the way they exploit the transcriptional program underlying their neural crest, sympatho-adrenal origin remains unclear. Here, we identified the transcriptional signature distinguishing LR-NBs from HR-NBs, which consists mainly of genes that belong to the core sympatho-adrenal developmental program and are associated with favorable patient prognosis and with diminished disease progression. Gain- and loss-of-function experiments revealed that the top candidate gene of this signature, Neurexophilin-1 (NXPH1), has a dual impact on NB cell behavior in vivo: whereas NXPH1 and its receptor α-NRXN1 promote NB tumor growth by stimulating cell proliferation, they conversely inhibit organotropic colonization and metastasis. As suggested by RNA-seq analyses, these effects might result from the ability of NXPH1/α-NRXN signalling to restrain the conversion of NB cells from an adrenergic state to a mesenchymal one. Our findings thus uncover a transcriptional module of the sympatho-adrenal program that opposes neuroblastoma malignancy by impeding metastasis, and pinpoint NXPH1/α-NRXN signaling as a promising target to treat HR-NBs.This work was supported by grants from the Ministerio de Ciencia e Innovacion, Gobierno de España (MCINN; BFU2016-81887-REDT and BFU2016-77498-P) and the AsociaciĂłn Española Contra el Cancer (AECC CI_2016) to EM, from the Fondo de InvestigaciĂłn en Salud (FIS) - Instituto de salud Carlos III (PI14/00038) and the NEN association (Association of Families and Friends of Patients with Neuroblastoma) to CL, from the Instituto de Salud Carlos III-FSE (MS17/00037; PI18/00014; PI21/00020) to TC-T, from Instituto de Salud Carlos III (CP22/00127, co-funded by European Social Fund âInvesting in your futureâ) to BMJ, from the Agence Nationale pour la Recherche (ANR-17-CE14-0023-01, ANR-17-CE14-0009-02) and the city of Paris (Emergence program) to ELG, from ISCIII-FEDER (CP13/00189 and CPII18/00009) to AMC. LF received a PhD fellowship from the Spanish Ministry of Science, Education and Universities (FPU AP2012-2222). LT-D was funded by a FPI Fellowship (PRE2019-088005). GLD was supported by the AsociaciĂłn Española Contra el Cancer (AECC #AIO14142105LED)
CSF H3F3A K27M circulating tumor DNA copy number quantifies tumor growth and in vitro treatment response
https://deepblue.lib.umich.edu/bitstream/2027.42/145434/1/40478_2018_Article_580.pd
The PARP inhibitor olaparib enhances the sensitivity of Ewing sarcoma to trabectedin
ProducciĂłn CientĂficaRecent preclinical evidence has suggested that Ewing Sarcoma (ES) bearing
EWSR1-ETS fusions could be particularly sensitive to PARP inhibitors (PARPinh) in
combination with DNA damage repair (DDR) agents. Trabectedin is an antitumoral
agent that modulates EWSR1-FLI1 transcriptional functions, causing DNA damage.
Interestingly, PARP1 is also a transcriptional regulator of EWSR1-FLI1, and PARPinh
disrupts the DDR machinery. Thus, given the impact and apparent specificity of both
agents with regard to the DNA damage/DDR system and EWSR1-FLI1 activity in
ES, we decided to explore the activity of combining PARPinh and Trabectedin in in
vitro and in vivo experiments. The combination of Olaparib and Trabectedin was
found to be highly synergistic, inhibiting cell proliferation, inducing apoptosis, and
the accumulation of G2/M. The drug combination also enhanced ÎłH2AX intranuclear
accumulation as a result of DNA damage induction, DNA fragmentation and global DDR
deregulation, while EWSR1-FLI1 target expression remained unaffected. The effect of
the drug combination was corroborated in a mouse xenograft model of ES and, more
importantly, in two ES patient-derived xenograft (PDX) models in which the tumors
showed complete regression. In conclusion, the combination of the two agents leads
to a biologically significant deregulation of the DDR machinery that elicits relevant
antitumor activity in preclinical models and might represent a promising therapeutic
tool that should be further explored for translation to the clinical setting.Ministerio de EconomĂa y Competitividad (PI081828)Ministerio de EconomĂa y Competitividad (RD06/0020/0059 )Ministerio de EconomĂa y Competitividad (RD12/0036/0017)Ministerio de EconomĂa y Competitividad (PT13/0010/0056
An Integrated In Vitro and In Vivo High-Throughput Screen Identifies Treatment Leads for Ependymoma
SummaryUsing a mouse model of ependymomaâa chemoresistant brain tumorâwe combined multicell high-throughput screening (HTS), kinome-wide binding assays, and in vivo efficacy studies, to identify potential treatments with predicted toxicity against neural stem cells (NSC). We identified kinases within the insulin signaling pathway and centrosome cycle as regulators of ependymoma cell proliferation, and their corresponding inhibitors as potential therapies. FDA approved drugs not currently used to treat ependymoma were also identified that posses selective toxicity against ependymoma cells relative to normal NSCs both in vitro and in vivo, e.g., 5-fluorouracil. Our comprehensive approach advances understanding of the biology and treatment of ependymoma including the discovery of several treatment leads for immediate clinical translation
Highlights of children with Cancer UKâs workshop on drug delivery in paediatric brain tumours
The first Workshop on Drug Delivery in Paediatric Brain Tumours was hosted in London by the charity Children with Cancer UK. The goals of the workshop were to break down the barriers to treating central nervous system (CNS) tumours in children, leading to new collaborations and further innovations in this under-represented and emotive field. These barriers include the physical delivery challenges presented by the bloodâbrain barrier, the underpinning reasons for the intractability of CNS cancers, and the practical difficulties of delivering cancer treatment to the brains of children. Novel techniques for overcoming these problems were discussed, new models brought forth, and experiences compared
Combination Therapies Targeting ALK-aberrant Neuroblastoma in Preclinical Models
PURPOSE
ALK-activating mutations are identified in approximately 10% of newly diagnosed neuroblastomas and ALK amplifications in a further 1%-2% of cases. Lorlatinib, a third-generation anaplastic lymphoma kinase (ALK) inhibitor, will soon be given alongside induction chemotherapy for children with ALK-aberrant neuroblastoma. However, resistance to single-agent treatment has been reported and therapies that improve the response duration are urgently required. We studied the preclinical combination of lorlatinib with chemotherapy, or with the MDM2 inhibitor, idasanutlin, as recent data have suggested that ALK inhibitor resistance can be overcome through activation of the p53-MDM2 pathway.
EXPERIMENTAL DESIGN
We compared different ALK inhibitors in preclinical models prior to evaluating lorlatinib in combination with chemotherapy or idasanutlin. We developed a triple chemotherapy (CAV: cyclophosphamide, doxorubicin, and vincristine) in vivo dosing schedule and applied this to both neuroblastoma genetically engineered mouse models (GEMM) and patient-derived xenografts (PDX).
RESULTS
Lorlatinib in combination with chemotherapy was synergistic in immunocompetent neuroblastoma GEMM. Significant growth inhibition in response to lorlatinib was only observed in the ALK-amplified PDX model with high ALK expression. In this PDX, lorlatinib combined with idasanutlin resulted in complete tumor regression and significantly delayed tumor regrowth.
CONCLUSIONS
In our preclinical neuroblastoma models, high ALK expression was associated with lorlatinib response alone or in combination with either chemotherapy or idasanutlin. The synergy between MDM2 and ALK inhibition warrants further evaluation of this combination as a potential clinical approach for children with neuroblastoma
Integrated Molecular Meta-Analysis of 1,000 Pediatric High-Grade and Diffuse Intrinsic Pontine Glioma.
We collated data from 157 unpublished cases of pediatric high-grade glioma and diffuse intrinsic pontine glioma and 20 publicly available datasets in an integrated analysis of >1,000 cases. We identified co-segregating mutations in histone-mutant subgroups including loss of FBXW7 in H3.3G34R/V, TOP3A rearrangements in H3.3K27M, and BCOR mutations in H3.1K27M. Histone wild-type subgroups are refined by the presence of key oncogenic events or methylation profiles more closely resembling lower-grade tumors. Genomic aberrations increase with age, highlighting the infant population as biologically and clinically distinct. Uncommon pathway dysregulation is seen in small subsets of tumors, further defining the molecular diversity of the disease, opening up avenues for biological study and providing a basis for functionally defined future treatment stratification
Functional diversity and co-operativity between subclonal populations of paediatric glioblastoma and diffuse intrinsic pontine glioma cells
The failure to develop effective therapies for pediatric glioblastoma (pGBM) and diffuse intrinsic pontine glioma (DIPG) is in part due to their intrinsic heterogeneity. We aimed to quantitatively assess the extent to which this was present in these tumors through subclonal genomic analyses and to determine whether distinct tumor subpopulations may interact to promote tumorigenesis by generating subclonal patient-derived models in vitro and in vivo. Analysis of 142 sequenced tumors revealed multiple tumor subclones, spatially and temporally coexisting in a stable manner as observed by multiple sampling strategies. We isolated genotypically and phenotypically distinct subpopulations that we propose cooperate to enhance tumorigenicity and resistance to therapy. Inactivating mutations in the H4K20 histone methyltransferase KMT5B (SUV420H1), present in <1% of cells, abrogate DNA repair and confer increased invasion and migration on neighboring cells, in vitro and in vivo, through chemokine signaling and modulation of integrins. These data indicate that even rare tumor subpopulations may exert profound effects on tumorigenesis as a whole and may represent a new avenue for therapeutic development. Unraveling the mechanisms of subclonal diversity and communication in pGBM and DIPG will be an important step toward overcoming barriers to effective treatments
- âŠ