Citations

Background— Diastolic dysfunction associated with high blood pressure (BP) leads to cardiac remodeling and fibrosis and progression to congestive heart failure. B-type natriuretic peptide (BNP) has BP-lowering, antifibrotic, and antihypertrophic properties, which makes BNP an attractive agent for attenuating the adverse cardiac remodeling associated with hypertension. In the current study, we tested the effects of sustained cardiac proBNP gene delivery on BP, cardiac function, and remodeling in spontaneously hypertensive rats (SHR). Methods and Results— We used the myocardium-tropic adeno-associated virus serotype 9 (AAV9) vector to achieve continuously enhanced cardiac rat proBNP expression. In SHR, a single systemic administration of AAV9 vector allowed long-term cardiac BNP overexpression, resulting in reductions in systolic and diastolic BP for 9 months after injection. Left ventricular (LV) thickness, LV end-systolic dimensions, and LV mass were reduced, whereas ejection fraction was significantly increased, in BNP-treated compared with untreated SHR. Circumferential systolic strain and strain rate of the early phase of diastole were improved in BNP-treated compared with untreated SHR. Noncardiac overexpression of BNP via AAV2 vector was not associated with changes in BP and plasma BNP in SHR. Furthermore, normal Wistar rats injected with AAV9 proBNP vector showed significantly reduced heart weights 4 weeks after injection without BP reduction. Conclusions— AAV9 vector facilitates sustained cardiac proBNP overexpression and improves LV function in hypertensive heart disease. Long-term proBNP delivery improved both systolic and diastolic function. The effects on cardiac structure and function occurred independently of BP-lowering effects in normal Wistar rats.

Abstract In July, 2009 the United States’ Food and Drug Agency (FDA) approved the use of a new biologically-targeted drug called ‘cetuximab’ (Erbitux) for the treatment of patients with advanced colorectal cancer (CRC). Cetuximab is a chimeric antibody directed against the extracellular domain of the epidermal growth factor receptor (EGFR). Paradoxically, EGFR expression, as it is currently measured by commercially available assays, has not been useful for predicting who will respond to cetuximab. We propose that one problem with these assays is their inability to measure EGFR and soluble EGFR (sEGFR) isoforms independently. We previously have documented the expression of an sEGFR isoform in human tissues (1), and have generated antibodies directed against a 31-mer peptide (residues 604-634) located within the unique 78 amino acid carboxy-terminal sequence of sEGFR (2). Interestingly, this anti-sEGFR antibody recognizes a second protein of ∼140-kDa (p140), which we have identified as human α5-integrin. Biochemical and mass spectrometry analyses show that a short region in the calf domain of α5-integrin shares sequence identity with the 31-mer sEGFR peptide. We have used this 31-mer antibody with an antibody directed against the intracellular domain of full-length EGFR to develop a novel EGFR vs. sEGFR/α5-integrin expression assay. This assay demonstrates that sEGFR/α5-integrin is co-expressed with EGFR in normal as well as malignant tissues, including in a number of carcinoma-derived cell lines. We also observe that high expression of EGFR and sEGFR/α5-integrin in a large cohort of ovarian cancer patients defines a strong adverse prognostic determinant of survival. These results implicate EGFR, sEGFR, and integrins as cancer biomarkers and demonstrate the critical importance of independently assessing both full-length and soluble EGFR isoforms in prognostic EGFR expression assays. *–JAW and ATB contributed equally to this study (1). Reiter et al. (2001) Genomics. 71(1):1-20 (2). Christensen et al. (2002) Hybrid Hybridomics. 21(3):183-9 Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4649.

ABSTRACTBackground:The relations between hepatic steatosis and histological features of hepatocyte injury in children with nonalcoholic fatty liver disease have yet to be examined. The aims of the present study were to establish associations between steatosis amount, type, and distribution in a well‐characterized group of children with biopsy‐proven nonalcoholic fatty liver disease (NAFLD).Patients and Methods:One hundred eight children with NAFLD seen in 5 centers were studied. Clinical and laboratory data were collected. Hematoxylin‐eosin and Masson trichrome stains were evaluated by 2 expert liver pathologists. Steatosis grade (0–3), type (macrovesicular, microvesicular, or mixed), and zone (1, 3, azonal, or panacinar) were determined. The NAFLD activity score and fibrosis stage were determined.Results:Median patient age was 12 years and median body mass index was 31 kg/m2. Fibrosis was present in 87%. The median NAFLD activity score was 4. Mild, moderate, and severe steatosis were present in 42%, 34%, and 24% of biopsies, respectively. Macrovesicular steatosis was present in 81% and mixed steatosis was present in 19%. Panacinar distribution of steatosis was most frequent (40%), followed by azonal (27%). Steatosis grade positively correlated with portal inflammation (P = 0.018). Azonal distribution positively correlated with presence of hepatocyte ballooning (P = 0.03). Biopsies with mixed steatosis were approximately 20 times more likely to have megamitochondria than those with macrovesicular steatosis alone (95% confidence interval 2.3–204.9). There was no relation between steatosis amount, type, or distribution to fibrosis stage.Conclusions:Specific histological patterns of steatosis in children are associated with histological markers of steatohepatitis. Ballooning and portal inflammation correlated well with features of steatosis.

Purpose Myelofibrosis is a myeloid malignancy associated with anemia, splenomegaly, and constitutional symptoms. Patients frequently harbor JAK-STAT activating mutations that are sensitive to TG101348, a selective small-molecule Janus kinase 2 (JAK2) inhibitor. Patients and Methods In a multicenter phase I trial, oral TG101348 was administered once a day to patients with high- or intermediate-risk primary or post–polycythemia vera/essential thrombocythemia myelofibrosis. Results Fifty-nine patients were treated, including 28 in the dose-escalation phase. The maximum-tolerated dose was 680 mg/d, and dose-limiting toxicity was a reversible and asymptomatic increase in the serum amylase level. Forty-three patients (73%) continued treatment beyond six cycles; the median cumulative exposure to TG101348 was 380 days. Adverse events included nausea, vomiting, diarrhea, anemia, and thrombocytopenia; corresponding grades 3 to 4 incidence rates were 3%, 3%, 10%, 35%, and 24%. TG101348 treatment had modest effect on serum cytokine levels, but greater than half of the patients with early satiety, night sweats, fatigue, pruritus, and cough achieved rapid and durable improvement in these symptoms. By six and 12 cycles of treatment, 39% and 47% of patients, respectively, had achieved a spleen response per International Working Group criteria. The majority of patients with leukocytosis or thrombocytosis at baseline (n = 28 and n = 10, respectively) achieved normalization of blood counts after six (57% and 90%, respectively) and 12 (56% and 88%, respectively) cycles. A significant decrease in JAK2 V617F allele burden was observed at 6 months in mutation-positive patients (n = 51; P = .04), particularly in the subgroup with allele burden greater than 20% (n = 23; P < .01); the decrease was durable at 12 months. Conclusion TG101348 is well tolerated and produces significant reduction in disease burden and durable clinical benefit in patients with myelofibrosis.

ABSTRACTA novel gammaretrovirus, xenotropic murine leukemia virus-related virus (XMRV), has been identified in patients with prostate cancer and in patients with chronic fatigue syndromes. StandardMus musculuslaboratory mice lack a functional XPR1 receptor for XMRV and are therefore not a suitable model for the virus. In contrast, Gairdner's shrew-mice (Mus pahari) do express functional XPR1. To determine whetherMus paharicould serve as a model for XMRV, primaryMus paharifibroblasts and mice were infected with cell-free XMRV. Infection of cellsin vitroresulted in XMRV Gag expression and the production of XMRV virions. After intraperitoneal injection of XMRV intoMus paharimice, XMRV proviral DNA could be detected in spleen, blood, and brain. Intravenous administration of a green fluorescent protein (GFP) vector pseudotyped with XMRV produced GFP+CD4+T cells and CD19+B cells. Mice mounted adaptive immune responses against XMRV, as evidenced by the production of neutralizing and Env- and Gag-specific antibodies. Prominent G-to-A hypermutations were also found in viral genomes isolated from the spleen, suggesting intracellular restriction of XMRV infection by APOBEC3in vivo. These data demonstrate infection ofMus pahariby XMRV, potential cell tropism of the virus, and immunological and intracellular restriction of virus infectionin vivo. These data support the use ofMus paharias a model for XMRV pathogenesis and as a platform for vaccine and drug development against this potential human pathogen.

ABSTRACTTransgenic expression of the RNA-dependent RNA polymerase 3Dpolinhibited infection of Theiler's murine encephalitis virus (TMEV), a picornavirus from which it was derived. Here, we infected 3Dpoltransgenic mice with another picornavirus, as well as an alphaherpesvirus and a rhabdovirus. 3Dpoltransgenic FVB mice had significantly lower viral loads and survived longer after infection with all three types of viruses than nontransgenic FVB mice. Viral inhibition among three different types of virus by transgenic 3Dpolsuggests that the mechanism of action is not the direct interference with picornaviral 3Dpolbut instead may be the changing of host cells to an antiviral state before or after viral infection occurs, as basal interferon levels were higher in 3Dpoltransgenic mice before infection. Further study of this mechanism may open new possibilities for future antiviral therapy.

Abstract The Division of Lung Diseases of the National Heart, Lung, and Blood Institute, with the Office of Rare Diseases Research, held a workshop to identify priority areas and strategic goals to enhance and accelerate research that will result in improved understanding of the lung vasculature, translational research needs, and ultimately the care of patients with pulmonary vascular diseases. Multidisciplinary experts with diverse experience in laboratory, translational, and clinical studies identified seven priority areas and discussed limitations in our current knowledge, technologies, and approaches. The focus for future research efforts include the following: (1) better characterizing vascular genotype–phenotype relationships and incorporating systems biology approaches when appropriate; (2) advancing our understanding of pulmonary vascular metabolic regulatory signaling in health and disease; (3) expanding our knowledge of the biologic relationships between the lung circulation and circulating elements, systemic vascular function, and right heart function and disease; (4) improving translational research for identifying disease-modifying therapies for the pulmonary hypertensive diseases; (5) establishing an appropriate and effective platform for advancing translational findings into clinical studies testing; and (6) developing the specific technologies and tools that will be enabling for these goals, such as question-guided imaging techniques and lung vascular investigator training programs. Recommendations from this workshop will be used within the Lung Vascular Biology and Disease Extramural Research Program for planning and strategic implementation purposes.

Abstract Rationale Accurate, early identification of patients at risk for developing acute lung injury (ALI) provides the opportunity to test and implement secondary prevention strategies. Objectives To determine the frequency and outcome of ALI development in patients at risk and validate a lung injury prediction score (LIPS). Methods In this prospective multicenter observational cohort study, predisposing conditions and risk modifiers predictive of ALI development were identified from routine clinical data available during initial evaluation. The discrimination of the model was assessed with area under receiver operating curve (AUC). The risk of death from ALI was determined after adjustment for severity of illness and predisposing conditions. Measurements and Main Results Twenty-two hospitals enrolled 5,584 patients at risk. ALI developed a median of 2 (interquartile range 1–4) days after initial evaluation in 377 (6.8%; 148 ALI-only, 229 adult respiratory distress syndrome) patients. The frequency of ALI varied according to predisposing conditions (from 3% in pancreatitis to 26% after smoke inhalation). LIPS discriminated patients who developed ALI from those who did not with an AUC of 0.80 (95% confidence interval, 0.78–0.82). When adjusted for severity of illness and predisposing conditions, development of ALI increased the risk of in-hospital death (odds ratio, 4.1; 95% confidence interval, 2.9–5.7). Conclusions ALI occurrence varies according to predisposing conditions and carries an independently poor prognosis. Using routinely available clinical data, LIPS identifies patients at high risk for ALI early in the course of their illness. This model will alert clinicians about the risk of ALI and facilitate testing and implementation of ALI prevention strategies. Clinical trial registered with www.clinicaltrials.gov (NCT00889772).