Neural stem cells (NSCs) reside in specialized niches in the adult mammalian brain. The ventricular–subventricular zone (V‐SVZ), adjacent to the lateral ventricles, gives rise to olfactory bulb (OB) ...neurons, and some astrocytes and oligodendrocytes throughout life. In vitro assays have been widely used to retrospectively identify NSCs. However, cells that behave as stem cells in vitro do not reflect the identity, diversity, and behavior of NSCs in vivo. Novel tools including fluorescence activated cell sorting, lineage‐tracing, and clonal analysis have uncovered multiple layers of adult V‐SVZ NSC heterogeneity, including proliferation state and regional identity. In light of these findings, we reexamine the concept of adult NSCs, considering heterogeneity as a key parameter for analyzing their dynamics in vivo. V‐SVZ NSCs form a mosaic of quiescent (qNSCs) and activated cells (aNSCs) that reside in regionally distinct microdomains, reflecting their regional embryonic origins, and give rise to specific subtypes of OB interneurons. Prospective purification and transcriptome analysis of qNSCs and aNSCs has illuminated their molecular and functional properties. qNSCs are slowly dividing, have slow kinetics of neurogenesis in vivo, can be recruited to regenerate the V‐SVZ, and only rarely give rise to in vitro colonies. aNSCs are highly proliferative, undergo rapid clonal expansion of the neurogenic lineage in vivo, and readily form in vitro colonies. Key open questions remain about stem cell dynamics in vivo and the lineage relationship between qNSCs and aNSCs under homeostasis and regeneration, as well as context‐dependent plasticity of regionally distinct adult NSCs under different external stimuli. WIREs Dev Biol 2016, 5:640–658. doi: 10.1002/wdev.248
This article is categorized under:
Adult Stem Cells, Tissue Renewal, and Regeneration > Methods and Principles
Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches
Adult Stem Cells, Tissue Renewal, and Regeneration > Stem Cells and Aging
Ibrutinib is a first-in-class inhibitor of Bruton tyrosine kinase (BTK) and has shown single-agent activity in recurrent/refractory central nervous system (CNS) lymphoma. Clinical responses are often ...transient or incomplete, suggesting a need for a combination therapy approach. We conducted a phase 1b clinical trial to explore the sequential combination of ibrutinib (560 or 840 mg daily dosing) with high-dose methotrexate (HD-MTX) and rituximab in patients with CNS lymphoma (CNSL). HD-MTX was given at 3.5 g/m2 every 2 weeks for a total of 8 doses (4 cycles; 1 cycle = 28 days). Ibrutinib was held on days of HD-MTX infusion and resumed 5 days after HD-MTX infusion or after HD-MTX clearance. Single-agent daily ibrutinib was administered continuously after completion of induction therapy until disease progression, intolerable toxicity, or death. We also explored next-generation sequencing of circulating tumor DNA (ctDNA) in cerebrospinal fluid (CSF) before and during treatment. The combination of ibrutinib, HD-MTX, and rituximab was tolerated with an acceptable safety profile (no grade 5 events, 3 grade 4 events). No dose-limiting toxicity was observed. Eleven of 15 patients proceeded to maintenance ibrutinib after completing 4 cycles of the ibrutinib/HD-MTX/rituximab combination. Clinical responses occurred in 12 of 15 patients (80%). Sustained tumor responses were associated with clearance of ctDNA from the CSF. This trial was registered at www.clinicaltrials.gov as #NCT02315326.
•Ibrutinib/methotrexate/rituximab combination treatment is safe and shows promising clinical activity in CNSL.•Analysis of ctDNA in CSF may be useful to monitor disease burden in patients with CNSL.
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Nausea can be particularly prominent during the delayed period. Therefore, we performed a meta-analysis of the available randomised evidence to assess the average effect of palonosetron plus one-day ...dexamethasone (DEX; also called the DEX-sparing strategy) compared with palonosetron plus 3-day DEX for control of chemotherapy-induced nausea and vomiting (CINV), focusing on delayed nausea.
Eligible studies were identified through MEDLINE, Embase, and CENTRAL. Data on acute and delayed CINV were collected. Efficacy end points were complete response (CR; no vomiting, and no use of rescue medication), complete protection (CP; CR plus no clinically significant nausea), and total control (TC; CR plus no nausea) during the delayed period (days 2-5 after chemotherapy initiation). All randomised studies comparing palonosetron plus single-dose DEX (with or without another active agent) on day 1 followed by either no further DEX or additional DEX doses (both alone or in combination with another active agent) qualified.
Of 864 citations screened, 8 studies with 1970 patients were included in the meta-analysis. During the delayed period, the combined odds ratio (OR) for all comparisons was 0.92 (95% confidence interval CI, 0.76-1.12) for CR, 0.85 (95% CI, 0.71-1.03) for CP, and 0.92 (95% CI, 0.77-1.11) for TC in patients undergoing moderately emetogenic chemotherapy (MEC) or anthracycline and cyclophosphamide-containing chemotherapy (AC). The absolute risk difference (RD) computations for all end points in the delayed period did not exceed the threshold of - 4% (range, - 1% to - 4%). The effect was similar in subgroups defined by various study design parameters. The absolute RD computations in the acute period did not exceed the threshold of 1% (range, 0 to 1%). For one-day vs. 3-day DEX, numbers needed to be treated in order for one additional patient to not experience CR, CP and TC over the delayed period were 100, 25 and 50, respectively.
This meta-analysis demonstrates that DEX-sparing regimens do not cause any significant loss in protection against not only vomiting but also nausea induced by single-day MEC or AC during the delayed period. These data should lead clinicians to optimise use of prophylactic DEX in clinical practice.
Inhibitors of mutant isocitrate dehydrogenase (mIDH) 1 and 2 cancer-associated enzymes prevent the accumulation of the oncometabolite d-2-hydroxyglutarate (2-HG) and are under clinical investigation ...for the treatment of several cancers harboring an IDH mutation. Herein, we describe the discovery of vorasidenib (AG-881), a potent, oral, brain-penetrant dual inhibitor of both mIDH1 and mIDH2. X-ray cocrystal structures allowed us to characterize the compound binding site, leading to an understanding of the dual mutant inhibition. Furthermore, vorasidenib penetrates the brain of several preclinical species and inhibits 2-HG production in glioma tissue by >97% in an orthotopic glioma mouse model. Vorasidenib represents a novel dual mIDH1/2 inhibitor and is currently in clinical development for the treatment of low-grade mIDH glioma.
Antineoplastic drugs may induce several side effects, including chemotherapy-induced nausea and vomiting (CINV). Two neurotransmitters play a central role in mediating the emetic response: serotonin ...acting on the 5HT3 receptor and the substance P targeting the NK1 receptor. Indeed, a combination of a 5HT3 receptor antagonist (5HT3-RA) and a NK1 receptor antagonist (NK1-RA) together with dexamethasone has been shown to be very effective. In fact, this combination is actually widely used and recommended for CINV prophylaxis for highly emetogenic cisplatin-based adriamycin/cyclophosphamide (AC) and carboplatin-based regimens. NEPA (netupitant/palonosetron) is the only fixed combination antiemetic available and it is composed by the long-lasting second-generation 5HT3-RA palonosetron and the highly selective NK1-RA netupitant.
The aims of this short review were to analyze the role of NEPA in CINV prophylaxis and management taking in account the risk factors related to the patient and to the antineoplastic treatment.
CINV development is not only correlated to the emetogenic potential of the antineoplastic drugs but is also very influenced by the patient characteristics and history, such as gender, age, alcohol intake, nausea during pregnancy and motion sickness. In pivotal and post-registration studies, NEPA has demonstrated to be effective and safe in both highly and moderately emetogenic chemotherapy.
A proper assessment of both chemotherapy- and patient-related risk factors is paramount to properly evaluate an appropriate prophylaxis of CINV and NEPA by simplifying the therapy, guarantees fully adherence to antiemetic guidelines, and consequently improves the control of CINV, especially in high risk patients.
Transport of macromolecules through the nuclear pore by importins and exportins plays a critical role in the spatial regulation of protein activity. How cancer cells co-opt this process to promote ...tumorigenesis remains unclear. The epidermal growth factor receptor (EGFR) plays a critical role in normal development and in human cancer. Here we describe a mechanism of EGFR regulation through the importin β family member RAN-binding protein 6 (RanBP6), a protein of hitherto unknown functions. We show that RanBP6 silencing impairs nuclear translocation of signal transducer and activator of transcription 3 (STAT3), reduces STAT3 binding to the EGFR promoter, results in transcriptional derepression of EGFR, and increased EGFR pathway output. Focal deletions of the RanBP6 locus on chromosome 9p were found in a subset of glioblastoma (GBM) and silencing of RanBP6 promoted glioma growth in vivo. Our results provide an example of EGFR deregulation in cancer through silencing of components of the nuclear import pathway.
Purpose
Prevention of chemotherapy-induced nausea and vomiting (CINV) is particularly challenging for patients receiving highly emetogenic preparative regimens before autologous stem cell ...transplantation (ASCT) due to the daily and continuous emetogenic stimulus of the multiple day chemotherapy. While studies have shown effective prevention of CINV during the conditioning phase with NK
1
receptor antagonist (NK
1
RA)-containing regimens, there have been no studies evaluating antiemetic use during chemomobilization prior to ASCT.
Methods
This multicenter, open-label, phase IIa study evaluated the efficacy of every-other-day dosing of NEPA administered during chemomobilization in patients with relapsed-refractory aggressive non-Hodgkin’s lymphoma. Eighty-one patients participated.
Results
Response rates were 77.8% for complete response (no emesis and no rescue use), 72.8% for complete control (complete response and no more than mild nausea), 86.4% for no emesis, and 82.7% for no rescue use during the overall phase (duration of chemomobilization through 48 h after). NEPA was well tolerated with no treatment-related adverse events reported.
Conclusion
NEPA, administered with a simplified every-other-day schedule, show to be very effective in preventing CINV in patients at high risk of CINV undergoing to chemomobilization of hematopoietic stem cells prior to ASCT.
GSX2 is a homeobox transcription factor (TF) controlling the specification of the ventral lateral ganglionic eminence and its major derivative, the corpus striatum. Medium spiny neurons (MSNs) ...represent the largest cell component of the striatum and they are primarily affected in Huntington disease (HD). Here, we used CRISPR technology to generate a pluripotent GSX2-reporter human embryonic stem cell (hESC) line that can be leveraged to monitor striatal differentiation in real-time and to enrich for MSN-committed progenitors.
Specialized niches support the lifelong maintenance and function of tissue-specific stem cells. Adult neural stem cells in the ventricular-subventricular zone (V-SVZ) contact the cerebrospinal fluid ...(CSF), which flows through the lateral ventricles. A largely ignored component of the V-SVZ stem cell niche is the lateral ventricle choroid plexus (LVCP), a primary producer of CSF. Here we show that the LVCP, in addition to performing important homeostatic support functions, secretes factors that promote colony formation and proliferation of purified quiescent and activated V-SVZ stem cells and transit-amplifying cells. The functional effect of the LVCP secretome changes throughout the lifespan, with activated neural stem cells being especially sensitive to age-related changes. Transcriptome analysis identified multiple factors that recruit colony formation and highlights novel facets of LVCP function. Thus, the LVCP is a key niche compartment that translates physiological changes into molecular signals directly affecting neural stem cell behavior.
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•The lateral ventricle choroid plexus is a novel component of the adult V-SVZ niche•LVCP secretome supports the recruitment and proliferation of NSCs and their progeny•NSCs are especially sensitive to age-dependent changes in the LVCP secretome•Transcriptome analysis reveals novel facets of LVCP biology
Silva-Vargas et al. show that the lateral ventricle choroid plexus is a novel niche component for adult V-SVZ neural stem cells and their progeny and exhibits dynamic changes with aging.
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