Assessment of ST2 for risk of death following graft-versus-host disease in pediatric and adult age groups.

Assessment of prognostic biomarkers of nonrelapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT) in the pediatric age group is lacking. To address this need, we conducted a prospective cohort study with 415 patients at 6 centers: 170 were children age 10 years or younger and 245 were patients older than age 10 years (both children and adults were accrued from 2013 to 2018). The following 4 plasma biomarkers were assessed pre-HCT and at days +7, +14, and +21 post-HCT: stimulation-2 (ST2), tumor necrosis factor receptor 1 (TNFR1), regenerating islet-derived protein 3α (REG3α), and interleukin-6 (IL-6). We performed landmark analyses for NRM, dichotomizing the cohort at age 10 years or younger and using each biomarker median as a cutoff for high- and low-risk groups. Post-HCT biomarker analysis showed that ST2 (>26 ng/mL), TNFR1 (>3441 pg/mL), and REG3α (>25 ng/mL) are associated with NRM in children age 10 years or younger (ST2: hazard ratio [HR], 9.13; 95% confidence interval [CI], 2.74-30.38; P = .0003; TNFR1: HR, 4.29; 95% CI, 1.48-12.48; P = .0073; REG3α: HR, 7.28; 95% CI, 2.05-25.93; P = .0022); and in children and adults older than age 10 years (ST2: HR, 2.60; 95% CI, 1.15-5.86; P = .021; TNFR1: HR, 2.09; 95% CI, 0.96-4.58; P = .06; and REG3α: HR, 2.57; 95% CI, 1.19-5.55; P = .016). When pre-HCT biomarkers were included, only ST2 remained significant in both cohorts. After adjustment for significant covariates (race/ethnicity, malignant disease, graft, and graft-versus-host-disease prophylaxis), ST2 remained associated with NRM only in recipients age 10 years or younger (HR, 4.82; 95% CI, 1.89-14.66; P = .0056). Assays of ST2, TNFR1, and REG3α in the first 3 weeks after HCT have prognostic value for NRM in both children and adults. The presence of ST2 before HCT is a prognostic biomarker for NRM in children age 10 years or younger allowing for additional stratification. This trial was registered at www.clinicaltrials.gov as #NCT02194439.

Obesity as a Potential Risk Factor for Vincristine-induced Peripheral Neuropathy.

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer. Vincristine is a core chemotherapeutic agent for patients with ALL; unfortunately, ∼78% will develop vincristine-induced peripheral neuropathy (VIPN). VIPN can result in vincristine dose reductions that decrease therapeutic efficacy: making it important to understand which children are at highest risk for VIPN. We hypothesized that pediatric ALL patients who were obese at diagnosis would develop worse VIPN than healthy weight children with ALL within the first year. Our results confirmed that obese pediatric patients have significantly (P=0.03) worse VIPN than patients of healthy weight.

CYP3A5 genotype and its impact on vincristine pharmacokinetics and development of neuropathy in Kenyan children with cancer.

BACKGROUND: Vincristine (VCR) is a critical part of treatment in pediatric malignancies and is associated with dose-dependent peripheral neuropathy (vincristine-induced peripheral neuropathy [VIPN]). Our previous findings show VCR metabolism is regulated by the CYP3A5 gene. Individuals who are low CYP3A5 expressers metabolize VCR slower and experience more severe VIPN as compared to high expressers. Preliminary observations suggest that Caucasians experience more severe VIPN as compared to nonCaucasians. PROCEDURE: Kenyan children with cancer who were undergoing treatment including VCR were recruited for a prospective cohort study. Patients received IV VCR 2 mg/m2 /dose with a maximum dose of 2.5 mg as part of standard treatment protocols. VCR pharmacokinetics (PK) sampling was collected via dried blood spot cards and genotyping was conducted for common functional variants in CYP3A5, multi-drug resistance 1 (MDR1), and microtubule-associated protein tau (MAPT). VIPN was assessed using five neuropathy tools. RESULTS: The majority of subjects (91%) were CYP3A5 high-expresser genotype. CYP3A5 low-expresser genotype subjects had a significantly higher dose and body surface area normalized area under the curve than CYP3A5 high-expresser genotype subjects (0.28 ± 0.15 hr·m2 /l vs. 0.15 ± 0.011 hr·m2 /l, P = 0.027). Regardless of which assessment tool was utilized, minimal neuropathy was detected in this cohort. There was no difference in the presence or severity of neuropathy assessed between CYP3A5 high- and low-expresser genotype groups. CONCLUSION: Genetic factors are associated with VCR PK. Due to the minimal neuropathy observed in this cohort, there was no demonstrable association between genetic factors or VCR PK with development of VIPN. Further studies are needed to determine the role of genetic factors in optimizing dosing of VCR for maximal benefit.

Weight gain and supplemental O2 : Risk factors during the hematopoietic cell transplant admission in pediatric patients.

BACKGROUND: Respiratory failure in the pediatric hematopoietic cell transplant (HCT) recipient is the leading cause for admission to the intensive care unit and carries a high mortality rate. The objective of this study is to investigate the association of clinical risk factors with the development of respiratory failure in the pediatric allogeneic HCT recipient. PROCEDURES: This is a single-center, retrospective review of allogeneic pediatric HCT from 2008 to 2014. Multiple variables were examined. The primary outcome was respiratory failure. Percent weight gain was investigated at multiple time points. Bivariate and multivariate regression was used. RESULTS: Of the 87 allogeneic HCT recipients, 22 (25%) developed respiratory failure. Mortality for entire cohort was 13.8%. All who died were intubated prior to death. The group with respiratory failure had significantly higher percent weight gain increase at multiple time points: peak weight prior to discharge or intubation (P = 0.008), weight at discharge or intubation (P = .001), and weight at day 43 (median day for intubation) (P = 0.02). Odds ratio (OR) for respiratory failure increased with increasing percentage peak weight gain: 10% increase (3.1 [1.1, 9.0]), 15% increase (4.1 [1.5, 11.2]), and 20% (8.3 [2.4. 28.9]). Fifty percent of all patients required supplemental O2 . OR for respiratory failure in patients requiring more than 1 l supplemental O2 is 25.3 (6.5, 98.7). CONCLUSION: Percent weight gain and need for supplemental oxygen is highly associated with the development of respiratory failure in pediatric HCT recipients, representing predictors of acute respiratory failure in pediatric HCT. These data could be incorporated into an algorithm that should be developed, implemented, and validated in a prospective, multicenter fashion.

Low serum albumin levels prior to pediatric allogeneic HCT are associated with increased need for critical care interventions and increased 6-month mortality.

Poor nutritional status in HCT patients is a negative prognostic factor. There are no pediatric studies evaluating albumin levels prior to HCT and need for critical care interventions. We hypothesized that pediatric patients with low albumin levels, routinely measured 30 days (±10 days) prior to allogeneic HCT, have a higher risk of critical care interventions in the post-transplant period. We performed a 5-year retrospective study of pediatric patients who underwent allogeneic HCT for any indication. Patients were categorized based on albumin level. Hypoalbuminemia was defined as <3.1 g/dL. A total of 73 patients were included, with a median age of 7.4 years (IQR 3.3, 13.2). Patients with hypoalbuminemia had higher needs for critical care interventions including non-invasive ventilation (44% vs 8%, P=.01), mechanical ventilation (67% vs 17%, P<.01), and vasoactive therapy (56% vs 16%, P=.01). Patients with hypoalbuminemia also had a higher 6-month mortality (56% vs 17%, P=.02). Our data demonstrate that children undergoing allogeneic HCT with hypoalbuminemia in the pretransplant period are more likely to require critical care interventions and have higher 6-month mortality. These findings identify an at-risk population in which nutritional improvements may be instituted prior to HCT in hopes of improving outcomes.

Hypoxia-Inducible Factor-1α Regulates CD55 in Airway Epithelium.

Airway epithelial CD55 down-regulation occurs in several hypoxia-associated pulmonary diseases, but the mechanism is unknown. Using in vivo and in vitro assays of pharmacologic inhibition and gene silencing, the current study investigated the role of hypoxia-inducible factor (HIF)-1α in regulating airway epithelial CD55 expression. Hypoxia down-regulated CD55 expression on small-airway epithelial cells in vitro, and in murine lungs in vivo; the latter was associated with local complement activation. Treatment with pharmacologic inhibition or silencing of HIF-1α during hypoxia-recovered CD55 expression in small-airway epithelial cells. HIF-1α overexpression or blockade, in vitro or in vivo, down-regulated CD55 expression. Collectively, these data show a key role for HIF-1α in regulating the expression of CD55 on airway epithelium.

Simultaneous quantification of mycophenolic acid and its glucuronide metabolites in human plasma by an UPLC-MS/MS assay.

The aim of this study was to develop a reliable UPLC-MS/MS assay for accurate quantification of mycophenolic acid (MPA) and its glucuronide conjugates in human plasma. Plasma proteins were precipitated with acetonitrile and the chromatographic separation was achieved on a C18 column with a gradient elution. The detection was performed by a triple quadrupole mass spectrometer in the positive electrospray ionization and multiple reaction monitoring mode. Linearity of the assay was demonstrated over the range of 20-10,000 ng/mL for MPA and MPA glucuronide (MPAG), and 2-1000 ng/mL for acyl MPA glucuronide in human plasma. The assay was precise and accurate with coefficient of variation and bias <15%. MPA and MPAG were stable at 25 °C up to 1 day in both heparin- and EDTA-treated blood. In heparin- and EDTA-plasma, MPA and MPAG were stable for at least 1 week at 25 and 4 °C, and 1 month at -20 °C. However, 99% acyl MPA glucuronide degraded in both heparin- and EDTA-blood as well as plasma when stored at room temperature for 1 day. All the analytes remained stable for at least 3 months in acidified EDTA-plasma at -80 °C. The assay was successfully applied on patients post hematopoietic stem cell transplantation. Copyright © 2016 John Wiley & Sons, Ltd.

Biomarkers for Diagnosis and Prognosis of Sinusoidal Obstruction Syndrome after Hematopoietic Cell Transplantation.

Reliable, noninvasive methods for diagnosing and prognosing sinusoidal obstruction syndrome (SOS) early after hematopoietic cell transplantation (HCT) are needed. We used a quantitative mass spectrometry-based proteomics approach to identify candidate biomarkers of SOS by comparing plasma pooled from 20 patients with and 20 patients without SOS. Of 494 proteins quantified, we selected 6 proteins (L-Ficolin, vascular cell adhesion molecule-1 [VCAM1], tissue inhibitor of metalloproteinase-1, von Willebrand factor, intercellular adhesion molecule-1, and CD97) based on a differential heavy/light isotope ratio of at least 2 fold, information from the literature, and immunoassay availability. Next, we evaluated the diagnostic potential of these 6 proteins and 5 selected from the literature (suppression of tumorigenicity-2 [ST2], angiopoietin-2 (ANG2), hyaluronic acid [HA], thrombomodulin, and plasminogen activator inhibitor-1) in samples from 80 patients. The results demonstrate that together ST2, ANG2, L-Ficolin, HA, and VCAM1 compose a biomarker panel for diagnosis of SOS. L-Ficolin, HA, and VCAM1 also stratified patients at risk for SOS as early as the day of HCT. Prognostic Bayesian modeling for SOS onset based on L-Ficolin, HA, and VCAM1 levels on the day of HCT and clinical characteristics showed >80% correct prognosis of SOS onset. These biomarkers may provide opportunities for preemptive intervention to minimize SOS incidence and/or severity.

Patterns and severity of vincristine-induced peripheral neuropathy in children with acute lymphoblastic leukemia.

Vincristine, a critical component of combination chemotherapy treatment for pediatric acute lymphoblastic leukemia (ALL), can lead to vincristine-induced peripheral neuropathy (VIPN). Longitudinal VIPN assessments were obtained over 12 months from newly diagnosed children with ALL (N = 128) aged 1-18 years who received vincristine at one of four academic children's hospitals. VIPN assessments were obtained using the Total Neuropathy Score-Pediatric Vincristine (TNS©-PV), National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE©), Balis© grading scale, and Pediatric Neuropathic Pain Scale©-Five (PNPS©-5). Of children who provided a full TNS©-PV score, 85/109 (78%) developed VIPN (TNS©-PV ≥4). Mean TNS©-PV, grading scale, and pain scores were low. CTCAE©-derived grades 3 and 4 sensory and motor VIPN occurred in 1.6%/0%, and 1.9%/0% of subjects, respectively. VIPN did not resolve in months 8-12 despite decreasing dose density. VIPN was worse in older children. Partition cluster analysis revealed 2-3 patient clusters; one cluster (n = 14) experienced severe VIPN. In this population, VIPN occurs more commonly than previous research suggests, persists throughout the first year of treatment, and can be severe.

The relative contributions of CYP3A4 and CYP3A5 to the metabolism of vinorelbine.

Vinorelbine is a semisynthetic vinca alkaloid used in the treatment of advanced breast and non-small cell lung cancers. Vincristine, a related vinca alkaloid, is 9-fold more efficiently metabolized by CYP3A5 than by CYP3A4 in vitro. This study quantified the relative contribution of CYP3A4 and CYP3A5 to the metabolism of vinorelbine in vitro using cDNA-expressed human cytochrome P450s (P450s) and human liver microsomes (HLMs). CYP3A4 and CYP3A5 were identified as the P450s capable of oxidizing vinorelbine using a panel of human enzymes and selective P450 inhibitors in HLMs. For CYP3A4 coexpressed with cytochrome b5 (CYP3A4+b5) and CYP3A5+b5, the Michaelis-Menten constants for vinorelbine were 2.6 and 3.6 µM, respectively, but the Vmax of 1.4 pmol/min/pmol was common to both enzymes. In HLMs, the intrinsic clearance of vinorelbine metabolism was highly correlated with CYP3A4 activity, and there was no significant difference in intrinsic clearance between CYP3A5 high and low expressers. When radiolabeled vinorelbine substrate was used, there were clear qualitative differences in metabolite formation fingerprints between CYP3A4+b5 and CYP3A5+b5 as determined by NMR and mass spectrometry analysis. One major metabolite (M2), a didehydro-vinorelbine, was present in both recombinant and microsomal systems but was more abundant in CYP3A4+b5 incubations. We conclude that despite the equivalent efficiency of recombinant CYP3A4 and CYP3A5 in vinorelbine metabolism the polymorphic expression of CYP3A5, as shown by the kinetics with HLMs, may have a minimal effect on systemic clearance of vinorelbine.

Pharmacogenetic predictors of nausea and vomiting of pregnancy severity and response to antiemetic therapy: a pilot study.

BACKGROUND: Nausea and vomiting of pregnancy (NVP) is a common condition. The objective of this study was to evaluate the association between response to antiemetics in the treatment of NVP and genetic polymorphisms in the serotonin receptor subunit genes HTR3A and HTR3B. METHODS: Pregnant women ≥18 years of age with NVP starting antiemetic therapy with promethazine, prochlorperazine, metoclopramide, or ondansetron at ≤ 16 weeks gestational age were eligible. The study recruited 29 women with complete data and sampling who returned for their one week follow-up and were genotyped for HTR3A and HTR3B polymorphisms. Severity of NVP was captured (using Pregnancy Unique Quantification of Emesis (PUQE) and Quality of Life (QOL) tools) upon enrollment and after one week of antiemetic therapy. These measures were correlated with pharmacogenetic variability. RESULTS: Subjects with genotype associated with high serotonin affinity of the 5-HT3B receptor (rs1176744, CC) required more antiemetic medications (p < 0.001) than other subjects. Those with genotypes associated with increased expression of the 5-HT3A receptor subunit (rs1062613, CT or TT) had worse final PUQE scores (p = 0.01) than other subjects while rs3782025 variants carriers had significantly better initial (p = 0.02) and final (p = 0.02) PUQE scores than other subjects. CONCLUSIONS: HTR3B and HTR3A gene variants may contribute to variability in response to antiemetic therapy for NVP.

Nifedipine pharmacokinetics are influenced by CYP3A5 genotype when used as a preterm labor tocolytic.

OBJECTIVE: To characterize the pharmacokinetics and pharmacogenetics of nifedipine in pregnancy. STUDY DESIGN: Pregnant women receiving oral nifedipine underwent steady-state pharmacokinetic testing over one dosing interval. DNA was obtained and genotyped for cytochrome P450 (CYP) 3A5 and CYP3A4*1B. Nifedipine and oxidized nifedipine concentrations were measured in plasma, and pharmacokinetic parameters were compared between those women who expressed a CYP3A5*1 allele and those who expressed only variant CYP3A5 alleles (*3,*6, or *7). RESULTS: Fourteen women had complete data to analyze. Four women (29%) expressed variant CYP3A5; three of these women were also CYP3A4*1B allele carriers. The mean half-life of nifedipine was 1.68 ± 1.56 hours. The area under the curve from 0 to 6 hours for the women receiving nifedipine every 6 hours was 207 ± 138 µg·h /L. Oral clearance was different between high expressers and low expressers (232.0 ± 37.8 µg/mL versus 85.6 ± 45.0 µg/mL, respectively; p = 0.007). CONCLUSION: CYP3A5 genotype influences the oral clearance of nifedipine in pregnant women.

Identify potential driver genes for PAX-FOXO1 fusion-negative rhabdomyosarcoma through frequent gene co-expression network mining.

Background: Rhabdomyosarcoma (RMS) is a soft tissue sarcoma usually originated from skeletal muscle. Currently, RMS classification based on PAX-FOXO1 fusion is widely adopted. However, compared to relatively clear understanding of the tumorigenesis in the fusion-positive RMS, little is known for that in fusion-negative RMS (FN-RMS). Methods: We explored the molecular mechanisms and the driver genes of FN-RMS through frequent gene co-expression network mining (fGCN), differential copy number (CN) and differential expression analyses on multiple RMS transcriptomic datasets. Results: We obtained 50 fGCN modules, among which five are differentially expressed between different fusion status. A closer look showed 23% of Module 2 genes are concentrated on several cytobands of chromosome 8. Upstream regulators such as MYC, YAP1, TWIST1 were identified for the fGCN modules. Using in a separate dataset we confirmed that, comparing to FP-RMS, 59 Module 2 genes show consistent CN amplification and mRNA overexpression, among which 28 are on the identified chr8 cytobands. Such CN amplification and nearby MYC (also resides on one of the above cytobands) and other upstream regulators (YAP1, TWIST1) may work together to drive FN-RMS tumorigenesis and progression. Up to 43.1% downstream targets of Yap1 and 45.8% of the targets of Myc are differentially expressed in FN-RMS vs. normal comparisons, which also confirmed the driving force of these regulators. Discussion: We discovered that copy number amplification of specific cytobands on chr8 and the upstream regulators MYC, YAP1 and TWIST1 work together to affect the downstream gene co-expression and promote FN-RMS tumorigenesis and progression. Our findings provide new insights for FN-RMS tumorigenesis and offer promising targets for precision therapy. Experimental investigation about the functions of identified potential drivers in FN-RMS are in progress.

Prospective assessment of risk biomarkers of sinusoidal obstruction syndrome after hematopoietic cell transplantation.

BACKGROUNDCurrently, no laboratory tests exist to stratify for the risk of developing sinusoidal obstruction syndrome (SOS), an early endothelial complication after hematopoietic cell transplantation (HCT). Risk biomarkers of SOS have not been verified in a prospective cohort accounting for differences between practices across institutions. Herein, we aimed to define risk groups for SOS occurrence using 3 proteins: L-ficolin, hyaluronic acid (HA), and stimulation 2 (ST2). METHODSBetween 2017 and 2021, we prospectively accrued 80 pediatric patients across 4 US centers. Biomarkers were tested by ELISA blind to patient groupings and associated with SOS incidence on day 35 after HCT, and overall survival (OS) on day 100 after HCT. Cutpoints were identified using retrospective cohorts and applied to the prospective cohort.RESULTSCombination of the 3 biomarkers measured on day 3 after HCT in the prospective cohort provided 80% (95% CI 55%-100%) sensitivity and 73% (95% CI 62%-83%) specificity for risk of SOS occurrence. Patients with low L-ficolin were 9 times (95% CI 3-32) more likely to develop SOS, while patients with high HA and ST2 were 6.5 (95% CI 1.9-22.0) and 5.5 (95% CI 2.3-13.1) times more likely to develop SOS. These 3 markers also predicted worse day 100 OS - L-ficolin: HR, 10.0 (95% CI 2.2-45.1), P = 0.0002; HA: HR, 4.1 (95% CI 1.0-16.4), P = 0.031; and ST2: HR, 3.9 (95% CI 0.9-16.4), P = 0.04.CONCLUSIONL-ficolin, HA, and ST2 levels measured as early as 3 days after HCT improved risk stratification for SOS occurrence and OS and may guide risk-adapted preemptive therapy.TRIAL REGISTRATIONClinicalTrials.gov NCT03132337.FUNDINGNIH.

Risk factors for cisplatin-associated ototoxicity in pediatric oncology patients.

BACKGROUND: Cisplatin is an effective chemotherapy agent against several pediatric malignancies. One of its side effects is irreversible sensorineural hearing damage that is highly variable with a reported incidence of 22-70%. The aim of this study was to evaluate the incidence and identify clinical predictors of cisplatin-related ototoxicity. PROCEDURES: We performed a retrospective chart review of 102 pediatric patients who had completed cisplatin therapy for osteosarcoma, neuroblastoma, hepatoblastoma, or germ cell tumor. Patients were diagnosed at Riley Hospital for Children between January 1995 and June 2008, were less than 18 years old at diagnosis, and had normal hearing prior to therapy. Audiograms were scored using the Brock scale (0-4), a validated grading system for cisplatin-related hearing loss. RESULTS: Forty-two percent of the patients experienced hearing loss and 28% had moderate to severe ototoxicity (Brock score ≥2). Males were at significantly greater risk for developing hearing loss than were females (P = 0.005, OR 4.812). Age at cancer diagnosis was inversely related to severity of ototoxicity. Patients who suffered Brock grade 3 ototoxicity had a mean age of 4.5 years versus 11.5 years and 7.2 years for grades 1 and 2, respectively (P = 0.02). Cumulative cisplatin dose was also identified as a risk factor for development of ototoxicity (P = 0.03). CONCLUSIONS: Gender and cumulative dose are important clinical biomarkers of cisplatin ototoxicity. Severity of ototoxicity may be inversely related to age at time of exposure, with very young patients exhibiting higher grades of hearing loss following cisplatin therapy.

A biomarker panel for risk of early respiratory failure following hematopoietic cell transplantation.

Plasma biomarkers associated with respiratory failure (RF) following hematopoietic cell transplantation (HCT) have not been identified. Therefore, we aimed to validate early (7 and 14 days post-HCT) risk biomarkers for RF. Using tandem mass spectrometry, we compared plasma obtained at day 14 post-HCT from 15 patients with RF and 15 patients without RF. Six candidate proteins, from this discovery cohort or identified in the literature, were measured by enzyme-linked immunosorbent assay in day-7 and day-14 post-HCT samples from the training (n = 213) and validation (n = 119) cohorts. Cox proportional-hazard analyses with biomarkers dichotomized by Youden's index, as well as landmark analyses to determine the association between biomarkers and RF, were performed. Of the 6 markers, Stimulation-2 (ST2), WAP 4-disulfide core domain protein 2 (WFDC2), interleukin-6 (IL-6), and tumor necrosis factor receptor 1 (TNFR1), measured at day 14 post-HCT, had the most significant association with an increased risk for RF in the training cohort (ST2: hazard ratio [HR], 4.5, P = .004; WFDC2: HR, 4.2, P = .010; IL-6: HR, 6.9, P < .001; and TFNR1: HR, 6.1, P < .001) and in the validation cohort (ST2: HR, 23.2, P = .013; WFDC2: HR, 18.2, P = .019; IL-6: HR, 12.2, P = .014; and TFNR1: HR, 16.1, P = .001) after adjusting for the conditioning regimen. Using cause-specific landmark analyses, including days 7 and 14, high plasma levels of ST2, WFDC2, IL-6, and TNFR1 were associated with an increased HR for RF in the training and validation cohorts. These biomarkers were also predictive of mortality from RF. ST2, WFDC2, IL-6 and TNFR1 levels measured early posttransplantation improve risk stratification for RF and its related mortality.

Integrative Multi-OMICs Identifies Therapeutic Response Biomarkers and Confirms Fidelity of Clinically Annotated, Serially Passaged Patient-Derived Xenografts Established from Primary and Metastatic Pediatric and AYA Solid Tumors.

Establishment of clinically annotated, molecularly characterized, patient-derived xenografts (PDXs) from treatment-naïve and pretreated patients provides a platform to test precision genomics-guided therapies. An integrated multi-OMICS pipeline was developed to identify cancer-associated pathways and evaluate stability of molecular signatures in a panel of pediatric and AYA PDXs following serial passaging in mice. Original solid tumor samples and their corresponding PDXs were evaluated by whole-genome sequencing, RNA-seq, immunoblotting, pathway enrichment analyses, and the drug−gene interaction database to identify as well as cross-validate actionable targets in patients with sarcomas or Wilms tumors. While some divergence between original tumor and the respective PDX was evident, majority of alterations were not functionally impactful, and oncogenic pathway activation was maintained following serial passaging. CDK4/6 and BETs were prioritized as biomarkers of therapeutic response in osteosarcoma PDXs with pertinent molecular signatures. Inhibition of CDK4/6 or BETs decreased osteosarcoma PDX growth (two-way ANOVA, p < 0.05) confirming mechanistic involvement in growth. Linking patient treatment history with molecular and efficacy data in PDX will provide a strong rationale for targeted therapy and improve our understanding of which therapy is most beneficial in patients at diagnosis and in those already exposed to therapy.

Collection of human genomic DNA from neonates: a comparison between umbilical cord blood and buccal swabs.

OBJECTIVE: To compare DNA yield from neonatal umbilical cord blood and buccal swab specimens. STUDY DESIGN: Umbilical cord blood was obtained at birth in a cohort of women enrolled in a preterm labor study. If cord blood was not obtained, neonatal buccal samples were obtained using the Oragene saliva kits. DNA was extracted from all samples using the QIAamp extraction kits. DNA concentration and yield were compared between umbilical cord blood and buccal swabs. RESULTS: DNA concentrations from umbilical cord blood (n = 35) was greater than that obtained from buccal swabs (n = 20) (total sample: 209.0 ± 110.7 ng/µL vs 6.9 ± 6.7 ng/µL respectively, P < .001; partial sample: n = 30 cord blood vs n = 11 buccal, 70.0 ± 51.4 ng/µL vs 11.3 ± 6.7 ng/µL, respectively, P < .001) and produced more total DNA (total sample: 116.5 ± 70.8 µg vs 4.2 ± 4.0 µg, P < .001; partial:14.0 ± 10.3 µg vs 1.1 ± 0.7 µg, respectively, P < .001). CONCLUSION: Buccal swabs yield less neonatal DNA than umbilical cord blood specimens.

Dactinomycin and vincristine toxicity in the treatment of childhood cancer: a retrospective study from the Children's Oncology Group.

BACKGROUND: Dactinomycin (AMD) and vincristine (VCR) have been used for the treatment of childhood cancer over the past 40 years but evidence-based dosing guidance is lacking. METHODS: Patient AMD and VCR dose and drug-related adverse event (AE) information from four rhabdomyosarcoma (RMS) and two Wilms tumor (WT) studies were assembled. Statistical modeling was used to account for differences in AE data collection across studies, develop rate models for grade 3/4 CTCAE v3 hepatic- (AMD) and neuro- (VCR) toxicity, assess variation in toxicity rates over age and other factors, and predict toxicity risk under current dosing guidelines. RESULTS: For the same dose/body size, AMD toxicity rates were higher in patients <1 year than older patients and VCR toxicity rates increased with age. The statistical model provided estimates for AMD and VCR toxicity risk under current dosing schedules and indicated that patients of smaller body size were at lower risk of VCR toxicity than larger patients of the same age. The rate of AMD toxicity was highest early in treatment and was lower in patients who tolerated initial AMD without toxicity. CONCLUSION: The observed decrease in AMD toxicity rate with cumulative dose may indicate sensitivity in a subgroup of patients while the observed increase in VCR toxicity risk with age may indicate changing sensitivity to VCR. Current dosing practices result in a fairly uniform toxicity profile within age group. However, PK/PD studies should be done to provide further provide further information on best dosing guidelines.