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5,186 result(s) for "Neuroblastoma - metabolism"
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Comparative pharmacokinetics, safety, and tolerability of two sources of ch14.18 in pediatric patients with high-risk neuroblastoma following myeloablative therapy
Purpose Dinutuximab (Unituxin™; ch14.18), a monoclonal antibody against disialoganglioside, improved survival as part of post-consolidation therapy for high-risk neuroblastoma. United Therapeutics Corporation (UTC) assumed ch14.18 production from the National Cancer Institute (NCI); this study evaluates pharmacokinetic comparability, safety, and tolerability of UTC and NCI products. Methods In this randomized, two-sequence crossover study, 28 patients aged ≤8 years with high-risk neuroblastoma received equivalent ch14.18-UTC or ch14.18-NCI doses. Despite comparable protein content, nominal doses differed: 17.5 mg/m 2 /day (ch14.18-UTC) and 25 mg/m 2 /day (ch14.18-NCI). Patients received one product during therapy cycles 1 and 2, the other during cycles 3–5. Ch14.18 pharmacokinetic profile characterization used population modeling (NONMEM ® version 7.2). A two-compartment model with first-order distribution and elimination processes described pharmacokinetic data. Estimated product parameters were normalized to UTC nominal dose. For pharmacokinetic comparability, the final model was used to estimate exposure ratios (UTC/NCI) and associated 90 % confidence intervals (CIs) for area under the curve from time zero to infinity (AUC inf ) and maximum concentration ( C max ). All comparisons were based on a standardized single-dose regimen (17.5 mg/m 2 over 10 h). Results Final-model pharmacokinetic parameters were similar to previously published ch14.18-NCI parameters and comparable for UTC and NCI products. Products’ systemic exposures were comparable, with 90 % CIs around ratios for AUC inf (0.96; 90 % CI 0.88–1.04) and C max (1.04; 90 % CI 0.98–1.11) within standard bioequivalence bounds (90 % CI 0.80–1.25). Products’ adverse events were similar and consistent with those previously reported. Conclusions Equivalent actual ch14.18-UTC and ch14.18-NCI doses produced comparable exposures, with no notable safety or tolerability differences.
Nano-targeted induction of dual ferroptotic mechanisms eradicates high-risk neuroblastoma
High-risk neuroblastoma is a devastating malignancy with very limited therapeutic options. Here, we identify withaferin A (WA) as a natural ferroptosis-inducing agent in neuroblastoma, which acts through a novel double-edged mechanism. WA dose-dependently either activates the nuclear factor-like 2 pathway through targeting of Kelch-like ECH-associated protein 1 (noncanonical ferroptosis induction) or inactivates glutathione peroxidase 4 (canonical ferroptosis induction). Noncanonical ferroptosis induction is characterized by an increase in intracellular labile Fe(II) upon excessive activation of heme oxygenase-1, which is sufficient to induce ferroptosis. This double-edged mechanism might explain the superior efficacy of WA as compared with etoposide or cisplatin in killing a heterogeneous panel of high-risk neuroblastoma cells, and in suppressing the growth and relapse rate of neuroblastoma xenografts. Nano-targeting of WA allows systemic application and suppressed tumor growth due to an enhanced accumulation at the tumor site. Collectively, our data propose a novel therapeutic strategy to efficiently kill cancer cells by ferroptosis.
7-Dehydrocholesterol is an endogenous suppressor of ferroptosis
Ferroptosis is a form of cell death that has received considerable attention not only as a means to eradicate defined tumour entities but also because it provides unforeseen insights into the metabolic adaptation that tumours exploit to counteract phospholipid oxidation 1 , 2 . Here, we identify proferroptotic activity of 7-dehydrocholesterol reductase (DHCR7) and an unexpected prosurvival function of its substrate, 7-dehydrocholesterol (7-DHC). Although previous studies suggested that high concentrations of 7-DHC are cytotoxic to developing neurons by favouring lipid peroxidation 3 , we now show that 7-DHC accumulation confers a robust prosurvival function in cancer cells. Because of its far superior reactivity towards peroxyl radicals, 7-DHC effectively shields (phospho)lipids from autoxidation and subsequent fragmentation. We provide validation in neuroblastoma and Burkitt’s lymphoma xenografts where we demonstrate that the accumulation of 7-DHC is capable of inducing a shift towards a ferroptosis-resistant state in these tumours ultimately resulting in a more aggressive phenotype. Conclusively, our findings provide compelling evidence of a yet-unrecognized antiferroptotic activity of 7-DHC as a cell-intrinsic mechanism that could be exploited by cancer cells to escape ferroptosis. Proferroptotic activity of 7-dehydrocholesterol reductase is shown along with an unexpected prosurvival function of its substrate, 7-dehydrocholesterol, indicating a cell-intrinsic mechanism that could be used by cancer cells to protect phospholipids from oxidative damage and escape ferroptosis.
MYCN mediates TFRC-dependent ferroptosis and reveals vulnerabilities in neuroblastoma
MYCN amplification is tightly associated with the poor prognosis of pediatric neuroblastoma (NB). The regulation of NB cell death by MYCN represents an important aspect, as it directly contributes to tumor progression and therapeutic resistance. However, the relationship between MYCN and cell death remains elusive. Ferroptosis is a newly identified cell death mode featured by lipid peroxide accumulation that can be attenuated by GPX4, yet whether and how MYCN regulates ferroptosis are not fully understood. Here, we report that MYCN -amplified NB cells are sensitive to GPX4-targeting ferroptosis inducers. Mechanically, MYCN expression reprograms the cellular iron metabolism by upregulating the expression of TFRC , which encodes transferrin receptor 1 as a key iron transporter on the cell membrane. Further, the increased iron uptake promotes the accumulation of labile iron pool, leading to enhanced lipid peroxide production. Consistently, TFRC overexpression in NB cells also induces selective sensitivity to GPX4 inhibition and ferroptosis. Moreover, we found that MYCN fails to alter the general lipid metabolism and the amount of cystine imported by System X c (−) for glutathione synthesis, both of which contribute to ferroptosis in alternative contexts. In conclusion, NB cells harboring MYCN amplification are prone to undergo ferroptosis conferred by TFRC upregulation, suggesting that GPX4-targeting ferroptosis inducers or TFRC agonists can be potential strategies in treating MYCN -amplified NB.
TRIM37 controls cancer-specific vulnerability to PLK4 inhibition
Centrosomes catalyse the formation of microtubules needed to assemble the mitotic spindle apparatus 1 . Centrosomes themselves duplicate once per cell cycle, in a process that is controlled by the serine/threonine protein kinase PLK4 (refs. 2 , 3 ). When PLK4 is chemically inhibited, cell division proceeds without centrosome duplication, generating centrosome-less cells that exhibit delayed, acentrosomal spindle assembly 4 . Whether PLK4 inhibitors can be leveraged as a treatment for cancer is not yet clear. Here we show that acentrosomal spindle assembly following PLK4 inhibition depends on levels of the centrosomal ubiquitin ligase TRIM37. Low TRIM37 levels accelerate acentrosomal spindle assembly and improve proliferation following PLK4 inhibition, whereas high TRIM37 levels inhibit acentrosomal spindle assembly, leading to mitotic failure and cessation of proliferation. The Chr17q region containing the TRIM37 gene is frequently amplified in neuroblastoma and in breast cancer 5 – 8 , rendering these cancer types highly sensitive to PLK4 inhibition. We find that inactivating TRIM37 improves acentrosomal mitosis because TRIM37 prevents PLK4 from self-assembling into centrosome-independent condensates that serve as ectopic microtubule-organizing centres. By contrast, elevated TRIM37 expression inhibits acentrosomal spindle assembly through a distinct mechanism that involves degradation of the centrosomal component CEP192. Thus, TRIM37 is an essential determinant of mitotic vulnerability to PLK4 inhibition. Linkage of TRIM37 to prevalent cancer-associated genomic changes—including 17q gain in neuroblastoma and 17q23 amplification in breast cancer—may offer an opportunity to use PLK4 inhibition to trigger selective mitotic failure and provide new avenues to treatments for these cancers. Acentrosomal assembly of the mitotic spindle upon inhibition of the PLK4 protein is shown to depend on the ubiquitin ligase TRIM37, with implications for the use of PLK4 inhibitors to treat neuroblastoma and breast cancer.
Small molecule inhibits α-synuclein aggregation, disrupts amyloid fibrils, and prevents degeneration of dopaminergic neurons
Parkinson’s disease (PD) is characterized by a progressive loss of dopaminergic neurons, a process that current therapeutic approaches cannot prevent. In PD, the typical pathological hallmark is the accumulation of intracellular protein inclusions, known as Lewy bodies and Lewy neurites, which are mainly composed of α-synuclein. Here, we exploited a high-throughput screening methodology to identify a small molecule (SynuClean-D) able to inhibit α-synuclein aggregation. SynuClean-D significantly reduces the in vitro aggregation of wild-type α-synuclein and the familiar A30P and H50Q variants in a substoichiometric molar ratio. This compound prevents fibril propagation in protein-misfolding cyclic amplification assays and decreases the number of α-synuclein inclusions in human neuroglioma cells. Computational analysis suggests that SynuClean-D can bind to cavities in mature α-synuclein fibrils and, indeed, it displays a strong fibril disaggregation activity. The treatment with SynuClean-D of two PD Caenorhabditis elegans models, expressing α-synuclein either in muscle or in dopaminergic neurons, significantly reduces the toxicity exerted by α-synuclein. SynuClean-D–treated worms show decreased α-synuclein aggregation in muscle and a concomitant motility recovery. More importantly, this compound is able to rescue dopaminergic neurons from α-synuclein–induced degeneration. Overall, SynuClean-D appears to be a promising molecule for therapeutic intervention in Parkinson’s disease.
miR-9, a MYC/MYCN-activated microRNA, regulates E-cadherin and cancer metastasis
miRNAs can both promote and repress tumorigenesis, and directly control epithelial–mesenchymal transition (EMT). miR-9 (which is upregulated in breast cancer cells) is activated by MYC and MYCN, and regulates EMT and metastasis through direct control of E-cadherin. In contrast, tumour angiogenesis is controlled indirectly through effects on vascular endothelial growth factor (VEGF) expression. MicroRNAs (miRNAs) are increasingly implicated in regulating the malignant progression of cancer. Here we show that miR-9, which is upregulated in breast cancer cells, directly targets CDH1 , the E-cadherin-encoding messenger RNA, leading to increased cell motility and invasiveness. miR-9-mediated E-cadherin downregulation results in the activation of β -catenin signalling, which contributes to upregulated expression of the gene encoding vascular endothelial growth factor (VEGF); this leads, in turn, to increased tumour angiogenesis. Overexpression of miR-9 in otherwise non-metastatic breast tumour cells enables these cells to form pulmonary micrometastases in mice. Conversely, inhibiting miR-9 by using a 'miRNA sponge' in highly malignant cells inhibits metastasis formation. Expression of miR-9 is activated by MYC and MYCN, both of which directly bind to the mir-9-3 locus. Significantly, in human cancers, miR-9 levels correlate with MYCN amplification, tumour grade and metastatic status. These findings uncover a regulatory and signalling pathway involving a metastasis-promoting miRNA that is predicted to directly target expression of the key metastasis-suppressing protein E-cadherin.
Heterogeneity of neuroblastoma cell identity defined by transcriptional circuitries
Isabelle Janoueix-Lerosey, Valentina Boeva and colleagues analyze the super-enhancer landscape of 25 neuroblastoma cell lines to define core regulatory circuits controlling gene expression programs. They find and functionally characterize two types of cell identity that contribute to the tumor heterogeneity of neuroblastoma. Neuroblastoma is a tumor of the peripheral sympathetic nervous system 1 , derived from multipotent neural crest cells (NCCs). To define core regulatory circuitries (CRCs) controlling the gene expression program of neuroblastoma, we established and analyzed the neuroblastoma super-enhancer landscape. We discovered three types of identity in neuroblastoma cell lines: a sympathetic noradrenergic identity, defined by a CRC module including the PHOX2B, HAND2 and GATA3 transcription factors (TFs); an NCC-like identity, driven by a CRC module containing AP-1 TFs; and a mixed type, further deconvoluted at the single-cell level. Treatment of the mixed type with chemotherapeutic agents resulted in enrichment of NCC-like cells. The noradrenergic module was validated by ChIP-seq. Functional studies demonstrated dependency of neuroblastoma with noradrenergic identity on PHOX2B, evocative of lineage addiction. Most neuroblastoma primary tumors express TFs from the noradrenergic and NCC-like modules. Our data demonstrate a previously unknown aspect of tumor heterogeneity relevant for neuroblastoma treatment strategies.
Sequencing of neuroblastoma identifies chromothripsis and defects in neuritogenesis genes
Whole-genome sequencing of neuroblastoma, a childhood tumour of the nervous system, shows that chromothripsis (a local shredding of chromosomes) and mutations in genes regulating neurite growth are associated with the most aggressive tumours. Neuroblastoma genomes analysed Whole-genome sequencing is used here to identify genetic defects in 87 people with neuroblastoma, a childhood tumour of the peripheral sympathetic nervous system. Analyses revealed few recurrent amino-acid-changing mutations, but a series of genes functioning in neuritogenesis and extension of neuronal growth cones were deleted in aggressive high-stage tumours. Chromothripsis, the localized shattering of the chromosomes, was common in high-stage tumours and was generally associated with poor prognosis. Neuroblastoma is a childhood tumour of the peripheral sympathetic nervous system. The pathogenesis has for a long time been quite enigmatic, as only very few gene defects were identified in this often lethal tumour 1 . Frequently detected gene alterations are limited to MYCN amplification (20%) and ALK activations (7%) 2 , 3 , 4 , 5 . Here we present a whole-genome sequence analysis of 87 neuroblastoma of all stages. Few recurrent amino-acid-changing mutations were found. In contrast, analysis of structural defects identified a local shredding of chromosomes, known as chromothripsis, in 18% of high-stage neuroblastoma 6 . These tumours are associated with a poor outcome. Structural alterations recurrently affected ODZ3 , PTPRD and CSMD1 , which are involved in neuronal growth cone stabilization 7 , 8 , 9 . In addition, ATRX , TIAM1 and a series of regulators of the Rac/Rho pathway were mutated, further implicating defects in neuritogenesis in neuroblastoma. Most tumours with defects in these genes were aggressive high-stage neuroblastomas, but did not carry MYCN amplifications. The genomic landscape of neuroblastoma therefore reveals two novel molecular defects, chromothripsis and neuritogenesis gene alterations, which frequently occur in high-risk tumours.
Orally bioavailable CDK9/2 inhibitor shows mechanism-based therapeutic potential in MYCN-driven neuroblastoma
The undruggable nature of oncogenic Myc transcription factors poses a therapeutic challenge in neuroblastoma, a pediatric cancer in which MYCN amplification is strongly associated with unfavorable outcome. Here, we show that CYC065 (fadraciclib), a clinical inhibitor of CDK9 and CDK2, selectively targeted MYCN-amplified neuroblastoma via multiple mechanisms. CDK9 - a component of the transcription elongation complex P-TEFb - bound to the MYCN-amplicon superenhancer, and its inhibition resulted in selective loss of nascent MYCN transcription. MYCN loss led to growth arrest, sensitizing cells for apoptosis following CDK2 inhibition. In MYCN-amplified neuroblastoma, MYCN invaded active enhancers, driving a transcriptionally encoded adrenergic gene expression program that was selectively reversed by CYC065. MYCN overexpression in mesenchymal neuroblastoma was sufficient to induce adrenergic identity and sensitize cells to CYC065. CYC065, used together with temozolomide, a reference therapy for relapsed neuroblastoma, caused long-term suppression of neuroblastoma growth in vivo, highlighting the clinical potential of CDK9/2 inhibition in the treatment of MYCN-amplified neuroblastoma.