Pleomorphic xanthoastrocytoma (PXA) is a rare subset of primary pediatric glioma with 70% 5-year disease free survival. However, up to 20% of cases present with local recurrence and malignant transformation into more aggressive type anaplastic PXA (AXPA) or glioblastoma. The understanding of disease etiology and mechanisms driving PXA and APXA are limited, and there is no standard of care.
View Article and Find Full Text PDFCancers (Basel)
December 2022
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.
View Article and Find Full Text PDFDespite improved therapeutic and clinical outcomes for patients with localized diseases, outcomes for pediatric and AYA sarcoma patients with high-grade or aggressive disease are still relatively poor. With advancements in next generation sequencing (NGS), precision medicine now provides a strategy to improve outcomes in patients with aggressive disease by identifying biomarkers of therapeutic sensitivity or resistance. The integration of NGS into clinical decision making not only increases the accuracy of diagnosis and prognosis, but also has the potential to identify effective and less toxic therapies for pediatric and AYA sarcomas.
View Article and Find Full Text PDFPurpose: Glioblastoma (GBM) is a malignant brain tumor with a poor long-term prognosis due to recurrence from highly resistant GBM cancer stem cells (CSCs), for which the current standard of treatment with temozolomide (TMZ) alone will unlikely produce a viable cure. In addition, CSCs regenerate rapidly and overexpress methyl transferase which overrides the DNA-alkylating mechanism of TMZ, leading to resistance. The objective of this research was to apply the concepts of nanotechnology to develop a multi-drug therapy, TMZ and idasanutlin (RG7388, a potent mouse double minute 2 (MDM2) antagonist), loaded in functionalized nanoparticles (NPs) that target the GBM CSC subpopulation, reduce the cell viability and provide possibility of in vivo preclinical imaging.
View Article and Find Full Text PDFCancers (Basel)
August 2020
Osteosarcoma (OS) patients exhibit poor overall survival, partly due to copy number variations (CNVs) resulting in dysregulated gene expression and therapeutic resistance. To identify actionable prognostic signatures of poor overall survival, we employed a systems biology approach using public databases to integrate CNVs, gene expression, and survival outcomes in pediatric, adolescent, and young adult OS patients. Chromosome 8 was a hotspot for poor prognostic signatures.
View Article and Find Full Text PDFThe Hippo pathway coordinates extracellular signals onto the control of tissue homeostasis and organ size. Hippo signaling primarily regulates the ability of Yap1 to bind and co-activate TEA domain (TEAD) transcription factors. Yap1 tightly binds to TEAD4 via a large flat interface, making the development of small-molecule orthosteric inhibitors highly challenging.
View Article and Find Full Text PDFThe ReninAAV db/db uNx model of diabetic kidney disease (DKD) exhibits hallmarks of advanced human disease, including progressive elevations in albuminuria and serum creatinine, loss of glomerular filtration rate, and pathological changes. Microarray analysis of renal transcriptome changes were more similar to human DKD when compared to db/db eNOS model. The model responds to treatment with arterial pressure lowering (lisinopril) or glycemic control (rosiglitazone) at early stages of disease.
View Article and Find Full Text PDFDiabetes mellitus (types 1 and 2) is the leading cause of glomerular disease and end-stage renal disease in most developed countries, with estimates that one-third of people living with diabetes will develop diabetic kidney disease (DKD). The current standard of care medications slow but do not arrest progression of kidney disease, and therefore, therapy for DKD is a highly unmet medical need for patients. To discover and test novel and durable new therapies, it is necessary to develop animal models of human DKD, which authentically recapitulate the human disease state and provide translatable efficacy to human patients.
View Article and Find Full Text PDFObjectives: The autonomic nervous system is critically involved in mediating the control by leptin of many physiological processes. Here, we examined the role of the leptin receptor (LepR) in proopiomelanocortin (POMC) and agouti-related peptide (AgRP) neurons in mediating the effects of leptin on regional sympathetic and parasympathetic nerve activity.
Methods: We analyzed how deletion of the LepR in POMC neurons (POMC/LepR mice) or AgRP neurons (AgRP/LepR mice) affects the ability of leptin to increase sympathetic and parasympathetic nerve activity.
Progress in research and developing therapeutics to prevent diabetic kidney disease (DKD) is limited by a lack of animal models exhibiting progressive kidney disease. Chronic hypertension, a driving factor of disease progression in human patients, is lacking in most available models of diabetes. We hypothesized that superimposition of hypertension on diabetic mouse models would accelerate DKD.
View Article and Find Full Text PDFAm J Physiol Renal Physiol
June 2017
Transforming growth factor-alpha (TGFA) has been shown to play a role in experimental chronic kidney disease associated with nephron reduction, while its role in diabetic kidney disease (DKD) is unknown. We show here that intrarenal mRNA expression, as well as urine and serum TGFA, are increased in human DKD. We used a TGFA neutralizing antibody to determine the role of TGFA in two models of renal disease, the remnant surgical reduction model and the uninephrectomized (uniNx) DKD model.
View Article and Find Full Text PDFOBJECTIVE Improvement in treatment outcome for patients with glioblastoma multiforme (GBM) requires a multifaceted approach due to dysregulation of numerous signaling pathways. The murine double minute 2 (MDM2) protein may fulfill this requirement because it is involved in the regulation of growth, survival, and invasion. The objective of this study was to investigate the impact of modulating MDM2 function in combination with front-line temozolomide (TMZ) therapy in GBM.
View Article and Find Full Text PDFTriple-negative breast cancers (TNBC) are typically resistant to treatment, and strategies that build upon frontline therapy are needed. Targeting the murine double minute 2 (Mdm2) protein is an attractive approach, as Mdm2 levels are elevated in many therapy-refractive breast cancers. The Mdm2 protein-protein interaction inhibitor Nutlin-3a blocks the binding of Mdm2 to key signaling molecules such as p53 and p73α and can result in activation of cell death signaling pathways.
View Article and Find Full Text PDFDrug Metab Dispos
September 2015
Effective treatments for primary brain tumors and brain metastases represent a major unmet medical need. Targeting the CDK4/CDK6-cyclin D1-Rb-p16/ink4a pathway using a potent CDK4 and CDK6 kinase inhibitor has potential for treating primary central nervous system tumors such as glioblastoma and some peripheral tumors with high incidence of brain metastases. We compared central nervous system exposures of two orally bioavailable CDK4 and CDK6 inhibitors: abemaciclib, which is currently in advanced clinical development, and palbociclib (IBRANCE; Pfizer), which was recently approved by the U.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
September 2015
Mice provide a unique platform to dissect disease pathogenesis, with the availability of recombinant inbred strains and diverse genetically modified strains. Leveraging these reagents to elucidate the mechanisms of hypertensive tissue injury has been hindered by difficulty establishing persistent hypertension in these inbred lines. ANG II infusion provides relatively short-term activation of the renin-angiotensinogen system (RAS) with concomitant elevated arterial pressure.
View Article and Find Full Text PDFObjectives: The purpose of the present study was to develop and validate noninvasive bioluminescence imaging methods for differentially monitoring primary and abdominal metastatic tumor growth in mouse orthotopic models of pancreatic cancer.
Methods: A semiautomated maximum entropy segmentation method was implemented for the primary tumor region of interest, and a rule-based method for manually drawing a region of interest for the abdominal metastatic region was developed for monitoring tumor growth in orthotopic models of pancreatic cancer. The 2 region-of-interest methods were validated by having 2 observers independently segment Panc-1 tumors, and the results were compared with the number of mesenteric lymph node nodules and histopathologic assessment of liver metastases.
J Pharmacol Exp Ther
May 2014
At least seven distinct epidermal growth factor (EGF) ligands bind to and activate the EGF receptor (EGFR). This activation plays an important role in the embryo and in the maintenance of adult tissues. Importantly, pharmacologic EGFR inhibition also plays a critical role in the pathophysiology of diverse disease states, especially cancer.
View Article and Find Full Text PDFThe adipocyte-derived hormone, leptin, is a master regulator of energy homeostasis. Leptin action in the central nervous system also contributes to arterial pressure regulation through its capacity to increase renal sympathetic outflow. The accumulating evidence pointing to a key role for leptin in the adverse sympathetic and cardiovascular consequences of excessive adiposity highlight the importance of understanding the mechanisms underlying the sympathetic and cardiovascular effects of leptin.
View Article and Find Full Text PDFUsing an innovative approach toward multiple carbon-carbon bond-formations that relies on the multifaceted catalytic properties of titanocene complexes we constructed a series of C1-C7 analogs of curcumin for evaluation as brain and peripheral nervous system anti-cancer agents. C2-Arylated analogs proved efficacious against neuroblastoma (SK-N-SH & SK-N-FI) and glioblastoma multiforme (U87MG) cell lines. Similar inhibitory activity was also evident in p53 knockdown U87MG GBM cells.
View Article and Find Full Text PDFWe have explored the decahydroisoquinoline scaffold, bearing a phenyl tetrazole, as GluK1 antagonists with potential as oral analgesics. We have established the optimal linker atom between decahydroisoquinoline and phenyl rings and demonstrated an improvement of both the affinity for the GluK1 receptor and the selectivity against the related GluA2 receptor with proper phenyl substitution. In this Letter, we also disclose in vivo data that led to the discovery of LY545694·HCl, a compound with oral efficacy in two persistent pain models.
View Article and Find Full Text PDFThe synthesis and structure-activity relationship of decahydroisoquinoline derivatives with various benzoic acid substitutions as GluK1 antagonists are described. Potent and selective antagonists were selected for a tailored prodrug approach in order to facilitate the evaluation of the new compounds in pain models after oral administration. Several diester prodrugs allowed for acceptable amino acid exposure and moderate efficacy in vivo.
View Article and Find Full Text PDFWe previously identified a distinct population of human circulating hematopoietic stem and progenitor cells (CHSPCs; CD14(-)glyA(-)CD34(+)AC133(+/-)CD45(dim)CD31(+) cells) in the peripheral blood (PB) and bone marrow, and their frequency in the PB can correlate with disease state. The proangiogenic subset (pCHSPC) play a role in regulating tumor progression, for we previously demonstrated a statistically significant increase in C32 melanoma growth in NOD.Cg-Prkdc (scid) (NOD/SCID) injected with human pCHSPCs (p < 0.
View Article and Find Full Text PDFThe fundamental importance of the hypothalamus in the regulation of autonomic and cardiovascular functions is well established. However, the molecular processes involved are not well understood. Here, we show that the mammalian (or mechanistic) target of rapamycin (mTOR) signaling in the hypothalamus is tied to the activity of the sympathetic nervous system and to cardiovascular function.
View Article and Find Full Text PDFPancreatic cancer often presents in advanced stages and is unresponsive to conventional treatments. Thus, the need to develop novel treatment strategies for pancreatic cancer has never been greater. Here, we report that combination of focal irradiation with hedgehog (Hh) signaling inhibition exerts better than additive effects on reducing metastases.
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