Single-cell genomics analysis reveals complex genetic interactions in an model of acquired BRAF inhibitor resistance.

The evolution of therapeutic resistance is a major obstacle to the success of targeted oncology drugs. While both inter- and intratumoral heterogeneity limit our ability to detect resistant subpopulations that pre-exist or emerge during treatment, our ability to analyze tumors with single-cell resolution is limited. Here, we utilized a cell-based transposon mutagenesis method to identify mechanisms of BRAF inhibitor resistance in a model of cutaneous melanoma.

Identifying patterns of neurocognitive dysfunction through direct comparison of children with leukemia, central nervous system tumors, and sickle cell disease.

Purpose: To quantify and compare the magnitude and type of neurocognitive dysfunction in at-risk children with central nervous system (CNS) tumors, acute lymphoblastic leukemia (ALL), and sickle cell disease (SCD) using a common instrument and metric to directly compare these groups with each other.

Methods: Fifty-three participants between the ages of 7 and 12 years (n = 27 ALL, n = 11 CNS tumor, n = 15 SCD) were enrolled and assessed using the NIH Toolbox Cognition Battery (NIHTCB). Participants with ALL or CNS tumor were 0-18 months posttherapy, while participants with SCD possessed the SS or Sβ genotype, took hydroxyurea, and had no known history of stroke.

Functional Genomic Screening Independently Identifies CUL3 as a Mediator of Vemurafenib Resistance via Src-Rac1 Signaling Axis.

Patients with malignant melanoma have a 5-year survival rate of only 15-20% once the tumor has metastasized to distant tissues. While MAP kinase pathway inhibitors (MAPKi) are initially effective for the majority of patients with melanoma harboring BRAF mutation, over 90% of patients relapse within 2 years. Thus, there is a critical need for understanding MAPKi resistance mechanisms.

Src-Dependent DBL Family Members Drive Resistance to Vemurafenib in Human Melanoma.

The use of selective BRAF inhibitors (BRAFi) has produced remarkable outcomes for patients with advanced cutaneous melanoma harboring a mutation. Unfortunately, the majority of patients eventually develop drug-resistant disease. We employed a genetic screening approach to identify gain-of-function mechanisms of BRAFi resistance in two independent melanoma cell lines.

Sleeping Beauty Mouse Models of Cancer: Microenvironmental Influences on Cancer Genetics.

The Sleeping Beauty (SB) transposon insertional mutagenesis system offers a streamlined approach to identify genetic drivers of cancer. With a relatively random insertion profile, SB is uniquely positioned for conducting unbiased forward genetic screens. Indeed, SB mouse models of cancer have revealed insights into the genetics of tumorigenesis.

A simplified transposon mutagenesis method to perform phenotypic forward genetic screens in cultured cells.

Background: The introduction of genome-wide shRNA and CRISPR libraries has facilitated cell-based screens to identify loss-of-function mutations associated with a phenotype of interest. Approaches to perform analogous gain-of-function screens are less common, although some reports have utilized arrayed viral expression libraries or the CRISPR activation system. However, a variety of technical and logistical challenges make these approaches difficult for many labs to execute.

The mitochondrial pyruvate carrier mediates high fat diet-induced increases in hepatic TCA cycle capacity.

Objective: Excessive hepatic gluconeogenesis is a defining feature of type 2 diabetes (T2D). Most gluconeogenic flux is routed through mitochondria. The mitochondrial pyruvate carrier (MPC) transports pyruvate from the cytosol into the mitochondrial matrix, thereby gating pyruvate-driven gluconeogenesis.

Chronic liver injury alters driver mutation profiles in hepatocellular carcinoma in mice.

Unlabelled: Most hepatocellular carcinomas (HCCs) develop in a chronically injured liver, yet the extent to which this microenvironment promotes neoplastic transformation or influences selective pressures for genetic drivers of HCC remains unclear. We sought to determine the impact of hepatic injury in an established mouse model of HCC induced by Sleeping Beauty transposon mutagenesis. Chemically induced chronic liver injury dramatically increased tumor penetrance and significantly altered driver mutation profiles, likely reflecting distinct selective pressures.

A Hybrid Adenoviral Vector System Achieves Efficient Long-Term Gene Expression in the Liver via piggyBac Transposition.

Much research has gone into the development of hybrid gene delivery systems that combine the broad tropism and efficient transduction of adenoviral vectors with the ability to achieve stable expression of cargo genes. In addition to gene therapy applications, such a system has considerable advantages for studies of gene function in vivo, permitting fine-tuned genetic manipulation with higher throughput than can be achieved using standard transgenic and DNA targeting techniques. Existing strategies are limited, however, by low integration efficiencies, small cargo capacity, and/or a dependence on target cell division.

EGFR inhibition induces proinflammatory cytokines via NOX4 in HNSCC.

Unlabelled: Chronic inflammation plays a fundamental role in tumor promotion, migration, and invasion. With the use of microarray profiling, a profound increase was observed for those transcripts involved in proinflammatory signaling in epidermal growth factor receptor (EGFR) inhibitor-treated head and neck squamous cell carcinoma (HNSCC) cells as compared with their respective controls. As such, it was hypothesized that EGFR inhibitor efficacy is offset by the proinflammatory response that these therapeutics conjure in HNSCC.

The secretory pathway calcium ATPase PMR-1/SPCA1 has essential roles in cell migration during Caenorhabditis elegans embryonic development.

Maintaining levels of calcium in the cytosol is important for many cellular events, including cell migration, where localized regions of high calcium are required to regulate cytoskeletal dynamics, contractility, and adhesion. Studies show inositol-trisphosphate receptors (IP3R) and ryanodine receptors (RyR), which release calcium into the cytosol, are important regulators of cell migration. Similarly, proteins that return calcium to secretory stores are likely to be important for cell migration.

Influence of proportional assist ventilation on diaphragmatic activity in normal subjects.

In six awake healthy adults we studied the physiological effects of mechanical unloading of the respiratory muscles during increased ventilatory demand. We were interested in whether respiratory muscle activity is down regulated and if this is mainly a consequence of chemical factors, i.e.

Mercury contamination of rat amylin mimics vasoactivity and cytotoxic effects.

Rat amylin differs from human amylin (hIAPP) in that it lacks a fibril-forming capacity. As a consequence, toxic effects have been reported for human but not for rat amylin. This report demonstrates how a mercury contamination of commercial rat amylin imitates peptide-related vasoactive and cytotoxic effects on preparations of isolated blood vessels.

Nitric oxide-dependent vasorelaxation and endothelial cell damage caused by mercury chloride.

Mercury and its derivatives are known to constrict vascular smooth muscle cells. However, little is known about the role of endothelial cells in mercury-induced vasoreactivity. Using isolated, norepinephrine preconstricted rat aorta and pulmonary artery rings with intact endothelium, we demonstrate that mercury chloride (HgCl2) induces an endothelial-dependent vasorelaxation which was totally blocked by the nitric oxide inhibitor L-NAME.

Vasorelaxant effect of glucagon-like peptide-(7-36)amide and amylin on the pulmonary circulation of the rat.

The gastrointestinal peptides glucagon-like peptide-1(7-36)amide (GLP-1) and amylin are currently being tested in clinical trials for the treatment of diabetes mellitus due to their effects in lowering blood glucose. Receptors for these polypeptides also exist in the lung and since polypeptides are known to modulate airway and pulmonary vascular tone, we investigated whether GLP-1 and amylin act similarly in the lung. We compared their effects with the well-known actions of calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP).

Effect of fixed minidose warfarin, conventional dose warfarin and aspirin on INR and prothrombin fragment 1 + 2 in patients with atrial fibrillation.

The efficacy of conventional dose adjusted oral anticoagulation for stroke prevention in patients with non-valvular atrial fibrillation is well-documented but not considered ideal as primary antithrombotic treatment in elderly patients. The antithrombotic effect of fixed minidose warfarin 1.25 mg/day alone or in combination with aspirin 300 mg/day, of conventional dose adjusted warfarin (INR 2.

[N-acetylcysteine decreases functional and structural, ARDS-typical lung changes in endotoxin-treated rats].

Oxygen radicals and oxygen radical mediators derived from activated granulocytes are important components in the development of acute lung injury, namely the adult respiratory distress syndrome ARDS. N-acetylcysteine (NAC) is one important substance for endogenous production of reduced glutathion, which is known to be an intra- and extracellular reducing agent also found in lung tissue. We evaluated the effect of exogenous NAC on the endotoxin induced development and course of ARDS in rats.