Partial monosomy 9p (9p22.2-->pter) and partial trisomy 18q (18q21.32-->qter) in a female infant with anorectal malformations

We report a female infant with a karyotype of 46,XX,der(9)t(9;18)(p22.2;q21.32)pat and the phenotypic features of craniofacial dysmorphisms, developmental delay, hypotonia, horizontal nystagmus, strabismus, congenital heart defects, clubfoot, and anorectal malformations with an anterior ectopic anus and a stenosed anal opening. Array comparative genomic hybridization revealed a 16.93-Mb deletion at 9p24.3-p22.2 encompassing the FREM1 gene and a 20.43-Mb duplication at 18q21.32-q23 encompassing the PIGN gene. We speculate that dual genome imbalances in FREMI at 9p22.3 and in PIGN at 18q21.3 are most likely responsible for the abnormal development of anorectum in this patient.

De novo satellited 2q associated with corpus callosum dysgenesis, short stature, mental retardation and developmental delay

We report the cytogenetic and molecular characterization of a 9.46-Mb terminal deletion of 2q in a 3-year-old girl with a de novo satellited 2q (2qs), corpus callosum dysgenesis, short stature, mental retardation and developmental delay. We speculate that haploinsufficiency of HDAC4 is responsible for short stature, mental retardation and developmental delay, and haploinsufficiency of EFHD1 is most likely responsible for the phenotype of corpus callosum dysgenesis in this patient.

Hypoxic preconditioning attenuates global cerebral ischemic injury following asphyxial cardiac arrest through regulation of delta opioid receptor system

This study was designed to investigate whether delta opioid receptor (DOR) is involved in the neuroprotective effect induced by hypoxic preconditioning (HPC) in the asphyxial cardiac arrest (CA) rat model. Twenty-four hours after the end of 7-day HPC, the rats were subjected to 8-min asphyxiation and resuscitated with a standardized method. In the asphyxial CA rat model, HPC improved the neurological deficit score (NDS), inhibited neuronal apoptosis, and increased the number of viable hippocampal CA1 neurons at 24 h, 72 h, or 7 days after restoration of spontaneous circulation (ROSC); however, the above-mentioned neuroprotection of HPC was attenuated by naltrindole (a selective DOR antagonist). The expression of hypoxia-inducible factor-1α (HIF-1α) and DOR, and the content of leucine enkephalin (L-ENK) in the brain were also investigated after the end of 7-day HPC. HPC upregulated the neuronal expression of HIF-1α and DOR, and synchronously elevated the content of L-ENK in the rat brain. HIF-1α siRNA was used to further elucidate the relationship between HIF-1α and DOR in the HPC-treated brain. Knockdown of HIF-1α by siRNA markedly abrogated the HPC induced upregulation of HIF-1α and DOR. The present study demonstrates that the expression of DOR in the rat brain is upregulated by HIF-1α following exposure to 7-day HPC, at the same time, HPC also increases the production of endogenous DOR ligand L-ENK in the brain. DOR activation after HPC results in prolonged neuroprotection against subsequent global cerebral ischemic injury, suggesting a new mechanism of HPC-induced neuroprotection on global cerebral ischemia following CA and resuscitation.

P4-09-09: Expression of c-MET and Phospho c-MET in Breast Cancers by Subtype and Its Impact on Survival Outcomes

Background

cMET is a tyrosine-kinase membrane receptor and its dysregulation is involved in tumor proliferation, survival, angiogenesis, and migration. High levels of cMET have been observed in various tumor types and correlate with adverse outcome. The purpose of this study was to evaluate levels of total cMET and phospho-cMET (p-cMET) in breast cancer and their impact on survival outcomes.

Materials and Methods: We measured quantitative expression of cMET and p-cMET in a cohort of 257 breast cancer primary tumor samples using reverse phase protein array. The level of cMET/p-cMET in each sample was expressed as a log-mean centered value after correction for protein loading with the use of the average expression levels of > 50 proteins. The regression tree method and Martingale residual plots were applied to find the best cutoff point for high and low levels of each protein. Linear regression models were used to determine if mean expression was different among breast cancer subtypes. The Kaplan-Meier method was used to estimate relapse-free survival (RFS) and overall survival (OS) by cMET and p-cMET levels. Cox proportional hazards models were fit to determine the association of cMET and p-cMET levels with the risk of recurrence and death after adjustment for other patient and disease characteristics.

Results: Median age was 51, (range 23–85) years. There were 140 (54.5%) hormone receptor (ER/PR)-positive, 53 (20.6%) HER2−positive, and 64 (24.9%) triple-negative tumors. Using the selected cutoffs, a total of 181 (70.4%) and 123 (47.9%) patients had high expression of cMET and p-cMET, respectively.

There were no significant differences in the mean expression of cMET (P<0.128) and p-cMET (P<0.088) by breast cancer subtype. Dichotomized cMET and p-cMET expression was a significant prognostic factor of RFS (HR: 0.41, 95% CI: 0.23−0.75, P=0.004, and HR: 0.61, 95% CI:0.38−0.96, P=0.033, respectively) and OS (HR: 0.31, 95% CI:0.14−0.70, P=0.005, and HR: 0.52, 95% CI:0.29−0.93, P=0.025, respectively). Within breast cancer subtypes, high cMET expression was associated with worse RFS (P=0.02) and OS (P=0.01) in ER/PR-positive tumors, and high p-cMET expression was associated with worse RFS (P=0.03) and OS (P=0.03) for patients with HER2−positive breast cancer. Multivariable model after adjustment for patient and tumor characteristics showed that patients with tumors with high cMET levels had a significant higher risk of recurrence (HR 0.28; 95% CI, 0.36−0.80) and death (HR 0.24; 95% CI, 0.09−0.65). Similarly, patients with tumors with high p-cMET levels had a significant higher risk of recurrence (HR 0.53; 95% CI, 0.29−0.97).

Conclusion: In this cohort of patients, high expression of cMET and p-cMET was seen in all subtypes of breast cancer. High levels of cMET and p-cMET had a significant impact on breast cancers survival outcomes. cMET inhibition may a be promising novel target for therapy in breast cancer and deserves investigation.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-09-09.

Enhancement of humoral immune responses to inactivated Newcastle disease and avian influenza vaccines by oral administration of ginseng stem-and-leaf saponins in chickens

Newcastle disease (ND) and avian influenza (AI) are common in the poultry industry. The objective of this study was to evaluate the effect of oral administration of ginseng stem-and-leaf saponins (GSLS) on the humoral immune responses of chickens to inactivated ND and AI vaccines. In experiment 1, oral administration of GSLS at a dose of 5 mg/kg of BW for 7 d on the immune response in chickens intramuscularly injected with inactivated ND vaccine was evaluated. Results showed that GSLS significantly increased the antibody level against ND in the serum of chickens. In experiment 2, the same regimen of GSLS was administered to chickens inoculated with inactivated AI vaccines, and an enhanced serum antibody response to AI vaccination was also observed. Considering the safety of GSLS, because no adverse effect was found throughout the experiments, GSLS may be a promising oral adjuvant to improve immunization in poultry.

Heme oxygenase-1: a molecular brake on hepatocellular carcinoma cell migration

Hepatocellular carcinoma (HCC) is a fatal disease with great public health impact worldwide. Heme oxygenase (HO)-1 has recently been reported as an important player in tumor angiogenesis and metastasis. However, the role of HO-1 in liver cancer metastasis is unclear. In this study, we explored genetic differences and downstream signal transduction pathways of HO-1 in liver cancer cell lines. HO-1 wild-type and mutant cell lines were generated from human liver cancer cell line HepG2. The overexpression of wild-type HO-1 decreased the migration of HepG2 cells. In contrast, the overexpression of mutant HO-1G143H increased the migration of the cancer cells. Interleukin (IL)-6 is one of the major downstream molecules that mediated this process because IL-6 expression and migration are suppressed by HO-1 and increased when HO-1 is knocked down by shRNA. In addition, we demonstrated carbon monoxide (CO) and p38MAPK are the cofactors in this signal pathway. In vivo animal model demonstrated HO-1 inhibited the tumor growth. In conclusion, in vitro and in vivo data show HO-1 inhibits the human HCC cells migration and tumor growth by suppressing the expression of IL-6. The heme degradation product CO is a cofactor in this process and inhibits p38MAPK phosphorylation.

Effects of patient education and progressive muscle relaxation alone or combined on adherence to continuous positive airway pressure treatment in obstructive sleep apnea patients

PURPOSE

The purpose of this study is to explore the effects of patient education and progressive muscle relaxation (PMR) alone or combined on adherence to continuous positive airway pressure (CPAP) treatment in obstructive sleep apnea (OSA) patients.

METHODS

One hundred and fifty-two Han Chinese OSA patients were randomly assigned to a control group (C), an education group (E), a PMR group (P), and an education + PMR group (E + P), with 38 patients each group. The adherence to CPAP was defined as 4 or more hours of CPAP usage per night and at least 9 of each 14 nights of ventilator use. The CPAP adherence rates, cumulative patient dropout rates, CPAP usage, and scores of daytime sleepiness, sleep quality, anxiety, and depression were compared among the groups at 4, 8, and 12 weeks of intervention.

RESULTS

All study groups were comparable in baseline characteristics. Group E + P showed significant improvement in CPAP adherence, daytime sleepiness, and sleep quality compared with group C at 4, 8, and 12 weeks of intervention. Compared with group C, group E only showed significant improvement in CPAP adherence, daytime sleepiness, and sleep quality at 4 weeks of intervention, while group P showed no significant improvement over time. Scores of anxiety and depression were significantly improved in group E + P compared with group C at 12 weeks of intervention.

CONCLUSIONS

Combined intervention with patient education and PMR can significantly improve CPAP adherence in OSA patients for at least 12 weeks. The intervention paradigm may serve as an important reference for future studies on CPAP adherence.

Levels of Circulating MMCN-151, a Degradation Product of Mimecan, Reflect Pathological Extracellular Matrix Remodeling in Apolipoprotein E Knockout Mice

AIM

Arterial extracellular matrix (ECM) remodeling by matrix metalloproteinases (MMPs) is one of the major hallmarks of atherosclerosis. Mimecan, also known as osteoglycin has been implicated in the integrity of the ECM. This study assessed the validity of an enzyme-linked immunosorbent assay (ELISA) developed to measure a specific MMP12-derived fragment of mimecan, MMCN-151, in apolipoprotein-E knockout (ApoE-KO) mice.

METHODS AND RESULTS

A mouse monoclonal antibody raised against MMCN-151 was used to develop a competitive ELISA. The assay was validated using samples from 20 ApoE-KO and 20 wild type [C57 BL/6] male mice fed a normal or high-fat diet (HFD) for up to 20 weeks. The technical reliability of the assay was established with intra-assay variability <2% and inter-assay variability <10%. The lowest limit of quantification of MMCN-151 was 0.5 ng/ml. ApoE-KO mice fed a HFD for 20 weeks had four-fold increased circulating levels of MMCN-151 compared to baseline, whereas MMCN-151 levels in control mice on HFD increased two-fold compared with baseline. After 10 weeks of a HFD, a significant difference in MMCN-151 levels was observed between ApoE-KO and control mice (P = 0.005) and became more significant at 20 weeks (P = 0.002).

CONCLUSIONS

The newly developed assay is a reliable detector of MMCN-151 levels which ultimately may be useful indicators of arterial remodeling in patients affected by atherosclerotic disease.

LOX-1 abrogation reduces cardiac hypertrophy and collagen accumulation following chronic ischemia in the mouse

We hypothesized that lectin-like oxidized LDL receptor-1 (LOX-1) deletion may inhibit oxidative stress signals, reduce collagen accumulation and attenuate cardiac remodeling after chronic ischemia. Activation of LOX-1 plays a significant role in the development of inflammation, apoptosis and collagen signals during acute ischemia. Wild-type and LOX-1 knockout (KO) mice were subjected to occlusion of left coronary artery for 3 weeks. Markers of cardiac hypertrophy, fibrosis-related signals (collagen IV, collagen-1 and fibronectin) and oxidant load (nicotinamide adenine dinucleotide phosphate oxidase expression, activity of mitogen-activated protein kinases and left ventricular (LV) tissue thiobarbituric acid reactive substances) were analyzed. In in vitro experiments, HL-1 cardiomyocytes were transfected with angiotensin II (Ang II) type 1 receptor (AT1R) or type 2 receptor (AT2R) genes to determine their role in the cardiomyocyte hypertrophy. LOX-1 KO mice had 25% improvement in survival over the 3-week period of chronic ischemia. LOX-1 deletion reduced collagen deposition and cardiomyocyte hypertrophy (∼75%) in association with a decrease in oxidant load and AT1R upregulation (all P<0.05). The LOX-1 KO mice hearts exhibited a disintegrin and metalloproteinase 10 (ADAM10) and a disintegrin and metalloproteinase 17 (ADAM17) expression and matrix metalloproteinase 2 activity, and increased AT2R expression (P<0.05). Attenuation of cardiac remodeling was associated with improved cardiac hemodynamics (LV ±dp/dt and cardiac ejection fraction). In vitro studies showed that it is AT1R, and not AT2R overexpression that induces cardiomyocyte hypertrophy. We demonstrate for the first time that LOX-1 deletion reduces oxidative stress and related intracellular signaling, which leads to attenuation of the positive feedback loop involving AT1R and LOX-1. This results in reduced chronic cardiac remodeling.

Abstract IA24: Drugging the undruggable: Small-molecule inhibition of Ras oncoprotein

Ras is a nucleotide-dependent switch that converts from an inactive GDP-bound state to an active GTP-bound state when activated by guanine nucleotide exchange factors, such as SOS. Active RasGTP then binds to and activates downstream signaling effectors. Ras is the most frequently mutated oncogene and hyperactive mutant Ras constitutively signals to effectors to promote cell survival, proliferation and metastasis. Thus, Ras oncoprotein has been considered by the cancer community to be one of the most important oncology drug targets. Despite the enormous interest and extensive exploratory efforts in industry and academia, small molecules that bind to Ras in a well-defined manner and exert inhibitory effects have not been uncovered to date. We report here the identification and characterization of small-molecule inhibitors of the Ras oncoprotein.

To explore a new means of directly targeting Ras, we used a fragment-based lead discovery approach via an NMR-based screen. Hits from the fragment screen were characterized for their interactions with Ras by NMR and X-ray crystallography and for their effects on Ras activation and signaling in reconstituted biochemical assays in vitro and in cellular assays in vivo. From the fragment-based screen, we identified a group of small molecules that each bind to a common site adjacent to the switch I/II regions in the Ras protein. X-ray crystallography studies of three compound-Ras complexes indicate that the binding site can be expanded upon ligand binding. Nucleotide exchange factors, notably SOS, are required to convert inactive RasGDP to active RasGTP. We determined that the compound-binding site is located at the interface of Ras and SOS. A subset of our Ras-binding molecules indeed inhibited SOS-mediated nucleotide exchange. Further mechanistic studies revealed that through steric hindrance the compounds block the formation of the Ras-SOS complex, a key intermediate of the exchange reaction. At the cellular level, our compounds inhibit the formation of active RasGTP and prevent Ras signaling to downstream effectors. To define the potential clinic utility of these compounds, we performed biological characterization of Ras-driven tumors and identified a subset of Ras mutant tumors that depend on nucleotide exchange factors for the activation of Ras, suggesting a specific profile for the use of exchange inhibitors.

We conclude that the compounds act as competitive inhibitors of nucleotide exchange to prevent the activation of Ras. The discovery of a binding pocket on Ras with functional significance represents a breakthrough finding that will offer a new direction for therapeutic intervention of Ras. Our findings provide new opportunities to target the “undruggable” Ras oncoprotein.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr IA24.