A59 GLOBAL PROTEOMIC PROFILING OF HUMAN COLONOID MONOLAYERS UNDERGOING IN VITRO CHRONIC DAMAGE

Background

An in vitro damage model has been established in our lab using human colonoids grown as 2D monolayers. Upon being subjected to repeated rounds of air-liquid interface (ALI) growth and injury by submergence, these colonoid monolayers lost their barrier integrity and regrowth potential. Changes in mRNA expression and DNA methylation in genes from this human model of injury were similar to those that occur in Inflammatory Bowel Disease (IBD) and colon cancer. Significant morphological changes were observed in these monolayers after they were subjected to subsequent rounds of submergence injury, compared to when they were differentiated in ALI.

Purpose

Submergence injury is predicted to be involved in unfolded protein response (UPR) activation which can specifically alter translation. Hence proteomics studies will help undertand these changes.

Method

To determine if these changes are mirrored in the proteomes of damaged colonoids, we employed a Single-Plot, Solid-Phase-enhanced Sample Preparation (SP3) technology for Mass Spectrometry (MS) based proteomics analysis to characterize these monolayers at baseline, once they were differentiated in ALI, after one and five rounds of injury after differentiation in ALI, and after stimulation with the Toll-like receptor 5 (TLR5) agonist FliC. Hierarchical clustering, enrichment analysis, volcano plot analysis after pre-processing and normalization of the proteomics data set revealed differentially expressed proteins across various groups of monolayers.

Result(s)

Preliminary proteomic data analysis revealed changes in the profile of proteins involved in cellular differentiation, mitochondrial proteins, hypoxia upregulated proteins, those responsible for the maintenance and reorganization of the cytoskeletal structure and Golgi structure. These changes in protein profile may account for the significant morphological changes observed in these monolayers when subjected to submergence injury. Some outliers in monolayers subjected to microbial stimulation included proteins involved in regulation of extracellular matrix dependent motility and components of Adaptor Protein Complexes. Further studies are needed to ascertain if these account for the protective effect of FliC on these monolayers.

Conclusion(s)

This study suggests that the submergence injury to these healthy human derived colonoid monolayers leads to changes in their protein profile which mirror those seen in case of acute and chronic inflammation like IBD and colon cancer. It corroborates with the findings of gene expression and epigenetic analyses using the in vitro model established in our lab.

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Disclosure of Interest

None Declared

Adverse outcomes with extracorporeal adsorbent blood treatments in toxic systemic inflammation: a perspective on possible mechanisms

Background

Extracorporeal blood purification (EBP) treatments may be used in patients with sepsis and related conditions to mitigate toxic systemic inflammation, prevent or reverse vital organ injury, and improve outcome. These treatments lack demonstrable efficacy, but are generally considered safe. However, since late 2020, four clinical studies of EBP treatment using adsorbent devices in inflammatory disease reported significantly increased patient mortality associated with the adsorbent treatments. Criticisms of study design and execution were published, but revealed no decisive flaws. None of these critiques considered possible toxic effects of the adsorbent treatments per se.

Perspective and conclusion

In adsorbent EBP treatment of systemic inflammatory disease the adsorbent media are deployed in patient blood or plasma flow for the purpose of broad spectrum, non-specific adsorptive removal of inflammatory mediators. Adsorption and sequestration of inflammatory mediators by adsorbent media is intended to reduce mediator concentrations in circulating blood and neutralize their activity. However, in the past two decades developments in both biomedical engineering and the science of cytokine molecular dynamics suggest that immobilization of inflammatory proteins on solid scaffolds or molecular carriers may stabilize protein structure and preserve or amplify protein function. It is unknown if these mechanisms are operative in EBP adsorbent treatments. If these mechanisms are operative, then the adsorbent medium could become reactive, promoting inflammatory activity which could result in negative outcomes. Considering the recent reports of harm with adsorbent treatments in diverse inflammatory conditions, caution urges investigation of these potentially harmful mechanisms in these devices. Candidate mechanisms for possible inquiry are discussed.

P2442Myocardial performance index predicts mortality in people with obstructive lung function from the general population

Background

Forced expiratory volume in one second (FEV1) is a significant predictor of mortality in patients with obstructive lung function (OL). Whether echocardiography can be used to identify patients at high risk, and whether it provides incremental prognostic information on mortality in patients with OL, remains unknown.

Methods

In a large, low-risk general population study, 1873 participants underwent a health examination with spirometry and echocardiography, including tissue Doppler imaging (TDI). The myocardial performance index (MPI) was calculated as the sum of the isovolumic contraction time (IVCT) and the isovolumic relaxation time (IVRT) divided by the left ventricle ejection time (LVET). Spirometry included measurements of (FEV1) and the forced vital capacity (FVC). OL was defined as FEV1/FVC <0.70. The primary endpoint was all-cause mortality.

Results

The mean age was 59±16 years, 57% were women, 43% had hypertension, 11% had diabetes, and 6% had ischemic heart disease. Of the 1873 included participants, 288 (15%) were classified as having OL at baseline. During follow up (median 13.7 years (IQR 13.2–16.2)), 584 (31%) persons died, hereof 178 (62%) in the subgroup of participants with OL and 406 (26%) in the subgroup of participants with normal lung function.

OL was associated with presence of left ventricular hypertrophy (higher left ventricular mass index), impaired diastolic function (lower E, higher A, lower E/A ratio, longer deceleration time, lower e' and higher E/e'), lower global longitudinal strain, and higher MPI.

In unadjusted analysis, higher MPI was associated with all-cause mortality for participants with OL (HR=1.18 (1.11–1.26), p<0.001, per 0.1 increase) and for participants with normal lung function (HR=1.42 (1.34–1.50), p<0.001, per 0.1 increase). The predictive value of MPI was significantly modified by the presence of obstructive lung function (p<0.001).

After multivariable adjustment for age, sex, FEV1/FVC, heart rate, systolic blood pressure, smoking status, body mass index (BMI), hypertension, diabetes, ischemic heart disease, ischemic stroke and heart failure at baseline, MPI remained an independent predictor of all-cause mortality (HR=1.19 (1.06–1.34), p=0.004, per 0.1 increase) for participants with OL but not for participants with normal lung function (HR=1.02 (0.94–1.11), p=0.598, per 0.1 increase).

When adding the MPI to the updated Age, Dyspnea and Obstruction (ADO) index, MPI provided incremental prognostic information beyond the updated ADO index, as determined from a significant increase in the Harrell's C-statistics (0.785 to 0.792, p=0.003).

Conclusion

Presence of OL is associated with subtle impairment of left ventricular systolic function, impaired left ventricular diastolic function, and higher MPI. MPI is an independent predictor of mortality in people with OL and provides incremental prognostic information regarding all-cause mortality in this population.

Acknowledgement/Funding

Herlev & Gentofte University Hospital PhD fund

Optimizing Seat Belt and Airbag Designs for Rear Seat Occupant Protection in Frontal Crashes

Recent field data have shown that the occupant protection in vehicle rear seats failed to keep pace with advances in the front seats likely due to the lack of advanced safety technologies. The objective of this study was to optimize advanced restraint systems for protecting rear seat occupants with a range of body sizes under different frontal crash pulses. Three series of sled tests (baseline tests, advanced restraint trial tests, and final tests), MADYMO model validations against a subset of the sled tests, and design optimizations using the validated models were conducted to investigate rear seat occupant protection with 4 Anthropomorphic Test Devices (ATDs) and 2 crash pulses. The sled tests and computer simulations were conducted with a variety of restraint systems including the baseline rear-seat 3-point belt, 3-point belts with a pre-tensioner, load limiter, dynamic locking tongue, 4-point belts, inflatable belts, Bag in Roof (BiR) concept, and Self Conforming Rear seat Air Bag (SCaRAB) concept. The results of the first two sled series demonstrated that the baseline 3-point belt system are associated with many injury measures exceeding injury assessment reference values (IARVs); showed the significance of crash pulse and occupant size in predicting injury risks; and verified the potential need of advanced restraint features for better protecting the rear-seat occupants. Good correlations between the tests and simulations were achieved through a combination of optimization and manual fine-tuning, as determined by a correlation method. Parametric simulations showed that optimized belt-only designs (3-point belt with pre-tensioner and load limiter) met all of the IARVs under the soft crash pulse but not the severe crash pulse, while the optimized belt and SCaRAB design met all the IARVs under both the soft and severe crash pulses. Two physical prototype restraint systems, namely an "advanced-belt only" design and an "advanced-belt and SCaRAB" design, were then tested in the final sled series. With the soft crash pulse, both advanced restraint systems were able to reduce all the injury measures below the IARVs for all four ATDs. Both advanced restraint systems also effectively reduced almost all the injury measures for all ATDs under the severe crash pulse, except for the THOR. The design with the advanced-belt and SCaRAB generally provided lower injury measures than those using the advanced belt-only design. This study highlighted the potential benefit of using advanced seatbelt and airbag systems for rear-seat occupant protection in frontal crashes.

Muscle α-adrenergic responsiveness during exercise and ATP-induced vasodilation in chronic obstructive pulmonary disease patients

Sympathetic vasoconstriction is blunted in exercising muscle (functional sympatholysis) but becomes attenuated with age. We tested the hypothesis that functional sympatholysis is further impaired in chronic obstructive pulmonary disease (COPD) patients. We determined leg blood flow and calculated leg vascular conductance (LVC) during 1) femoral-arterial Tyramine infusion (evokes endogenous norepinephrine release, 1 µmol·min^-1·kg leg mass^-1), 2) one-legged knee extensor exercise with and without Tyramine infusion [10 W and 20% of maximal workload (WL_max)], 3) ATP (0.05 µmol·min^-1·kg leg mass^-1) and Tyramine infusion, and 4) incremental ATP infusions (0.05, 0.3, and 3.0 µmol·min^-1·kg leg mass^-1). We included 10 patients with moderate to severe COPD and 8 age-matched healthy control subjects. Overall, leg blood flow and LVC were lower in COPD patients during exercise ( P < 0.05). Tyramine reduced LVC in both groups at 10-W exercise (COPD: -3 ± 1 ml·min^-1·mmHg^-1 and controls: -3 ± 1 ml·min^-1·mmHg^-1, P < 0.05) and 20% WL_max (COPD: -4 ± 1 ml·min^-1·mmHg^-1 and controls: -3 ± 1 ml·min^-1·mmHg^-1, P < 0.05) with no difference between groups. Incremental ATP infusions induced dose-dependent vasodilation with no difference between groups, and, in addition, the vasoconstrictor response to Tyramine infused together with ATP was not different between groups (COPD: -0.03 ± 0.01 l·min^-1·kg leg mass^-1 vs.

CONTROLS

-0.04 ± 0.01 l·min^-1·kg leg mass^-1, P > 0.05). Compared with age-matched healthy control subjects, the vasodilatory response to ATP is intact in COPD patients and their ability to blunt sympathetic vasoconstriction (functional sympatholysis) as evaluated by intra-arterial Tyramine during exercise or ATP infusion is maintained. NEW & NOTEWORTHY The ability to blunt sympathetic vasoconstriction in exercising muscle and ATP-induced dilation in chronic obstructive pulmonary disease patients remains unexplored. Chronic obstructive pulmonary disease patients demonstrated similar sympathetic vasoconstriction in response to intra-arterial Tyramine during exercise and ATP-induced vasodilation compared with age-matched healthy control subjects.

Leg blood flow is impaired during small muscle mass exercise in patients with COPD

Skeletal muscle blood flow is regulated to match the oxygen demand and dysregulation could contribute to exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). We measured leg hemodynamics and metabolites from vasoactive compounds in muscle interstitial fluid and plasma at rest, during one-legged knee-extensor exercise, and during arterial infusions of sodium nitroprusside (SNP) and acetylcholine (ACh), respectively. Ten patients with moderate to severe COPD and eight age- and sex-matched healthy controls were studied. During knee-extensor exercise (10 W), leg blood flow was lower in the patients compared with the controls (1.82 ± 0.11 vs. 2.36 ± 0.14 l/min, respectively; P < 0.05), which compromised leg oxygen delivery (372 ± 26 vs. 453 ± 32 ml O2/min, respectively; P < 0.05). At rest, plasma endothelin-1 (vasoconstrictor) was higher in the patients with COPD ( P < 0.05) and also tended to be higher during exercise ( P = 0.07), whereas the formation of interstitial prostacyclin (vasodilator) was only increased in the controls. There was no difference between groups in the nitrite/nitrate levels (vasodilator) in plasma or interstitial fluid during exercise. Moreover, patients and controls showed similar vasodilatory capacity in response to both endothelium-independent (SNP) and endothelium-dependent (ACh) stimulation. The results suggest that leg muscle blood flow is impaired during small muscle mass exercise in patients with COPD possibly due to impaired formation of prostacyclin and increased levels of endothelin-1.

NEW & NOTEWORTHY This study demonstrates that chronic obstructive pulmonary disease (COPD) is associated with a reduced blood flow to skeletal muscle during small muscle mass exercise. In contrast to healthy individuals, interstitial prostacyclin levels did not increase during exercise and plasma endothelin-1 levels were higher in the patients with COPD.

[Strategies for cerebrospinal fluid analysis - Integrated results report]

Cerebrospinal fluid (CSF) analysis requires a combined assessment of all individual test findings in an integrated total report in order to achieve a reliable and specific diagnostic conclusion. Such a standard assessment strategy allows the identification of disease-typical result patterns and plausibility checks to avoid analytical errors. The integrated total report consists of 1) a basic CSF program with cytological and protein chemical parameters, 2) an expanded CSF program with special parameters for detection of pathogens and markers of neurodegeneration and 3) a final contextual interpretation considering methodological and clinical aspects.

The effect of home oxygen therapy on hospitalization in moderate hypoxaemic COPD

Background: The aim of the study was to determine whether home oxygen therapy (HOT) reduces hospitalization in moderate hypoxaemic COPD patients. Methods: We studied 170 consecutive moderate hypoxaemic COPD patients (PaO2 on room air and rest: 7.3-9.5 kPa), who were treated with HOT for at least one month. The patients were acting as their own control. Admission rates,days spent in hospital and number of patients with at least one hospitalization were compared in twoperiods of 10 months before and after initiation of HOT. Results: The admission rates, number of days spent in hospital and number of patients with at least one hospitalization was not reduced(preoxygen period versus postoxygen period): 1.55 (2.00) versus 1.67 (2.26), 14.3 (19.9) versus 14.8(23.7), and 60.6% versus 61.2%-P-level > 0.05 for all three parameters. Conclusions: Our resultsdo not support the hypothesis that home oxygen therapy reduces hospitalization in patients with COPD without severe hypoxaemia. However, as this is not a randomized study, we cannot exclude that oxygen therapy has prevented progression of the disease, and that without this therapy, the hospitalization could have been even higher.

Characterization of a biologically derived rabbit tracheal scaffold

There is a clinical need to provide replacement tracheal tissue for the pediatric population affected by congenital defects, as current surgical solutions are not universally applicable. A potential solution is to use tissue engineered scaffold as the framework for regenerating autologous tissue. Rabbit trachea were used and different detergents (Triton x-100 and sodium deoxycholate) and enzymes (DNAse/RNAse) investigated to create a decellularization protocol. Each reagent was initially tested individually and the outcome used to design a combined protocol. At each stage the resultant scaffold was assessed histologically, molecularly for acellularity and matrix preservation. Immunogenicity of the final scaffold was assessed by implantation into a rat model for 4 weeks. Both enzymes and detergents were required to produce a completely acellular (DNA content 42.78 ng/mg) scaffold with preserved collagen and elastin however, GAG content were reduced (8.78 ± 1.35 vs. 5.5 ± 4.8). Following in vivo implantation the scaffold elicited minimal immune response and showed significant cellular infiltration and vasculogenesis. The luminal aspect of the implanted scaffold showed infiltration of host derived cells, which were positive for pan cytokeratin. It is possible to create biologically derived biocompatible scaffolds to address specific pediatric clinical problems. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2126-2135, 2017.

Characterization of single disseminated prostate cancer cells reveals tumor cell heterogeneity and identifies dormancy associated pathways

Cancer dormancy refers to the prolonged clinical disease-free time between removal of the primary tumor and recurrence, which is common in prostate cancer (PCa), breast cancer, esophageal cancer, and other cancers. PCa disseminated tumor cells (DTC) are detected in both patients with no evidence of disease (NED) and advanced disease (ADV). However, the molecular and cellular nature of DTC is unknown. We performed a first-in-field study of single DTC transcriptomic analyses in cancer patients to identify a molecular signature associated with cancer dormancy. We profiled eighty-five individual EpCAM⁺/CD45⁻ cells from the bone marrow of PCa patients with NED or ADV. We analyzed 44 DTC with high prostate-epithelial signatures, and eliminated 41 cells with high erythroid signatures and low prostate epithelial signatures. DTC were clustered into 3 groups: NED, ADV_1, and ADV_2, in which the ADV_1 group presented a distinct gene expression pattern associated with the p38 stress activated kinase pathway. Additionally, DTC from the NED group were enriched for a tumor dormancy signature associated with head and neck squamous carcinoma and breast cancer. This study provides the first clinical evidence of the p38 pathway as a potential biomarker for early recurrence and an attractive target for therapeutic intervention.

Pilot study of a novel vacuum-assisted method for decellularization of tracheae for clinical tissue engineering applications

Tissue engineered tracheae have been successfully implanted to treat a small number of patients on compassionate grounds. The treatment has not become mainstream due to the time taken to produce the scaffold and the resultant financial costs. We have developed a method for decellularization (DC) based on vacuum technology, which when combined with an enzyme/detergent protocol significantly reduces the time required to create clinically suitable scaffolds. We have applied this technology to prepare porcine tracheal scaffolds and compared the results to scaffolds produced under normal atmospheric pressures. The principal outcome measures were the reduction in time (9 days to prepare the scaffold) followed by a reduction in residual DNA levels (DC no-vac: 137.8±48.82 ng/mg vs. DC vac 36.83±18.45 ng/mg, p<0.05.). Our approach did not impact on the collagen or glycosaminoglycan content or on the biomechanical properties of the scaffolds. We applied the vacuum technology to human tracheae, which, when implanted in vivo showed no significant adverse immunological response. The addition of a vacuum to a conventional decellularization protocol significantly reduces production time, whilst providing a suitable scaffold. This increases clinical utility and lowers production costs. To our knowledge this is the first time that vacuum assisted decellularization has been explored. Copyright © 2015 John Wiley & Sons, Ltd.

Nanophase separation in monomolecularly thin water-ethanol films controlled by graphene

Control over nanoscale patterning of ultrathin molecular films plays an important role both in natural as well as artificial nanosystems. Here we report on nanophase separated patterns of water and ethanol within monomolecularly thin films confined between the cleavage plane of mica and single or a few layers of graphene. Employing scanning force microscopy of the graphene layers conforming to the molecular films we quantify the patterns using the ethanol-water cross correlation and the autocorrelation of domain wall directions. They reveal that lateral pattern dimensions grow and the domain walls stiffen upon increasing the thickness of the graphene multilayers. We attribute the control of the patterns through the graphene layers to the competition between the mechanical deformation energy of the graphene sheets and the electrostatic repulsion of dipoles normal to the interface. The latter results from charge transfer between graphene and the molecules confined between mica and graphene.

Abstract 1989: SRRM4 and the loss of REST may promote the emergence of the neuroendocrine /neuronal phenotype in castration resistant prostate cancer

Introduction: Recent findings suggest that neuroendocrine/neuronal (NE) differentiation may be associated with the development of metastatic castration-resistant prostate cancer (CRPC). Our objective was to characterize the NE phenotype in CRPC.

Methods: Using specimens obtained at rapid autopsy at the University of Washington, 2 tissue microarrays were made from (1) 155 metastatic sites from 50 autopsy patients who died from CRPC and (2) 24 LuCaP prostate cancer xenografts. NE markers, including Chromogranin A (CHGA), Synaptophysin (SYN), androgen receptor (AR), and prostate specific antigen (PSA) were analyzed by immunohistochemistry (IHC). To characterize the molecular features of the NE phenotype in CRPC, transcript levels in 78 corresponding metastatic sites and 24 LuCaP xenografts were determined by hybridization to whole genome microarrays.

Results: Co-expression of CHGA and SYN (by at least &gt;10% of cells) was observed in 22 of 155 sites (11 sites were AR-). PSA, a surrogate of AR activity, was absent in all NE CRPC tumors that did not express AR. Four of the 24 LuCaP xenografts displayed an NE phenotype (all were AR-). Gene expression data were generated from 78 laser captured metastases, and 24 LuCaP xenografts. Five metastatic sites were CHGA+, SYN+ and AR-, and 5 were CHGA+, SYN+ and AR+, 4 LuCaP xenografts were CHGA+, SYN+ and AR- by IHC. Only CHGA+, SYN+ sites had a NE transcript signature, with the CHGA+, SYN+ and AR- specimens expressing a greater number of genes associated with the NE phenotype. In addition, a decrease in the expression of REST was observed in the 10 CHGA+, SYN+ metastatic sites and LuCaP xenografts. SRRM4 transcript expression was associated with the NE signature in 5 of the 6 CHGA+, SYN+ patients and the LuCaP xenografts. Furthermore RT-PCR comparing the epithelial to the NE LuCaP xenografts correlated the expression of SRRM4 with a splice variant of REST that lacks the repressor domain and the NE phenotype.

Conclusions: Our data suggest that a) the CRPC NE phenotype can be defined by CHGA+, SYN+ dual positivity and is more common in CRPC than historically in hormone sensitive primary disease, b) NE status from different sites in the same patient can be heterogeneous c) the NE phenotype is not necessarily associated with the loss of AR activity, and d) the loss of REST expression or the splicing of REST through the activity of SRRM4 could promote the NE phenotype in CRPC. These molecular studies suggest that evolution from hormone sensitive, to castration resistant on to NE disease involves the loss of REST or the loss of REST repressor activity due to alternate splicing by SRRM4.

Citation Format: Xiaotun Zhang, Ilsa Coleman, Roger Coleman, Lisha Brown, Lori Kollath, Lisly Chéry, Jared Lucas, Eva Corey, Martine Roudier, Paul Lange, Celestia Higano, Lawrence True, Peter Nelson, Robert Vessella, Colm Morrissey. SRRM4 and the loss of REST may promote the emergence of the neuroendocrine /neuronal phenotype in castration resistant prostate cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1989. doi:10.1158/1538-7445.AM2014-1989

Contrast-induced acute kidney injury after computed tomography prior to transcatheter aortic valve implantation

AIM

To identify independent predictors of contrast medium-induced acute kidney injury (CI-AKI) after enhanced multidetector-row computed tomography (MDCT) prior to transcatheter aortic valve implantation (TAVI) in high-risk patients.

MATERIALS AND METHODS

The present single-centre study analysed retrospectively 361 patients who were assessed using MDCT prior to TAVI. CI-AKI was defined as an increase in serum creatinine (SCr) of ≥ 25% or ≥ 0.5 mg/dl in at least one sample over baseline (24 h before MDCT) and at 24, 48, and 72 h after MDCT.

RESULTS

A total of 38 patients (10.5%) experienced CI-AKI. As compared to patients without CI-AKI, they presented more frequently with estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2), (81.6% versus 64.4%, p = 0.045) and tended to receive higher volumes of iodinated contrast media (ICM; 55.3% versus 39%, p = 0.057). There was a significant interaction between baseline eGFR and the amount of intravenous ICM administered (pfor interaction = <0.001) identifying the amount of ICM >90 ml as independent predictive factor of CI-AKI only in patients with baseline eGFR <60 ml/min/1.73m(2) (OR 2.615; 95% CI: 1.21-5.64).

CONCLUSION

One in ten elderly patients with aortic stenosis undergoing MDCT to plan a TAVI procedure experienced CI-AKI after intravenous ICM injection. Intravenous administration of <90 ml of ICM reduces this risk in patients with or without pre-existing impaired renal function. However, in the majority of patients renal function recovers before the TAVI procedure.

Cerebrospinal fluid findings in geriatric patients from 2008 to 2011

BACKGROUND

The chemical composition of the cerebrospinal fluid (CSF) is age-dependent.

METHODS

Routine CSF parameters, the indications for lumbar puncture (LP), and the most frequent complications were retrospectively studied in patients older (n = 167) and younger (n = 36) than 65 years.

RESULTS

In the absence of meningeal inflammation, the mean CSF lactate level of patients older than 65 years was slightly but significantly higher than the mean CSF lactate level of younger patients. The lactate level of patients with otherwise normal CSF findings correlated significantly with the age of the patients. In the absence of meningeal inflammation, the CSF-to-serum albumin ratio (QAlbumin) was significantly higher in older patients than in younger ones. The most frequent indication for LP, suspected infection of the central nervous system (CNS) (n = 110), was confirmed in 12.7% of patients. The only LP complication documented was headache in two patients.

CONCLUSIONS

Elevations of QAlbumin and CSF lactate levels appear to be nonspecific findings in elderly patients. Suspected infections, the most frequent indication for LP, were confirmed by CSF analysis in more than 10% of patients. The very low complication rate of LP makes it a very valuable tool in the diagnostic routine for older patients with CNS diseases.

Targeted androgen pathway suppression in localized prostate cancer: a pilot study

PURPOSE

Ligand-mediated activation of the androgen receptor (AR) is critical for prostate cancer (PCa) survival and proliferation. The failure to completely ablate tissue androgens may limit suppression of PCa growth. We evaluated combinations of CYP17A and 5-α-reductase inhibitors for reducing prostate androgen levels, AR signaling, and PCa volumes.

PATIENTS AND METHODS

Thirty-five men with intermediate/high-risk clinically localized PCa were randomly assigned to goserelin combined with dutasteride (ZD), bicalutamide and dutasteride (ZBD), or bicalutamide, dutasteride, and ketoconazole (ZBDK) for 3 months before prostatectomy. Controls included patients receiving combined androgen blockade with luteinizing hormone-releasing hormone agonist and bicalutamide. The primary outcome measure was tissue dihydrotestosterone (DHT) concentration.

RESULTS

Prostate DHT levels were substantially lower in all experimental arms (0.02 to 0.04 ng/g v 0.92 ng/g in controls; P < .001). The ZBDK group demonstrated the greatest percentage decline in serum testosterone, androsterone, and dehydroepiandrosterone sulfate (P < .05 for all). Staining for AR and the androgen-regulated genes prostate-specific antigen and TMPRSS2 was strongly suppressed in benign glands and moderately in malignant glands (P < .05 for all). Two patients had pathologic complete response, and nine had ≤ 0.2 cm(3) of residual tumor (defined as a near-complete response), with the largest numbers of complete and near-complete responses in the ZBDK group.

CONCLUSION

Addition of androgen synthesis inhibitors lowers prostate androgens below that achieved with standard therapy, but significant AR signaling remains. Tissue-based analysis of steroids and AR signaling is critical to informing the search for optimal local and systemic control of high-risk prostate cancer.

Development, validation and application of a stable isotope dilution liquid chromatography electrospray ionization/selected reaction monitoring/mass spectrometry (SID-LC/ESI/SRM/MS) method for quantification of keto-androgens in human serum

Prostate cancer is the most frequently diagnosed form of cancer in males in the United States. The disease is androgen driven and the use of orchiectomy or chemical castration, known as androgen deprivation therapy (ADT) has been employed for the treatment of advanced prostate cancer for over 70 years. Agents such as GnRH agonists and non-steroidal androgen receptor antagonists are routinely used in the clinic, but eventually relapse occurs due to the emergence of castration-resistant prostate cancer. With the appreciation that androgen signaling still persists in these patients and the development of new therapies such as abiraterone and enzalutamide that further suppresses androgen synthesis or signaling, there is a renewed need for sensitive and specific methods to quantify androgen precursor and metabolite levels to assess drug efficacy. We describe the development, validation and application of a stable isotope dilution liquid chromatography electrospray ionization selected reaction monitoring mass spectrometry (SID-LC/ESI/SRM/MS) method for quantification of serum keto-androgens and their sulfate and glucuronide conjugates using Girard-T oxime derivatives. The method is robust down to 0.2-4pg on column, depending on the androgen metabolite quantified, and can also quantify dehydroepiandrosterone sulfate (DHEA-S) in only 1μL of serum. The clinical utility of this method was demonstrated by analyzing serum androgens from patients enrolled in a clinical trial assessing combinations of pharmacological agents to maximally suppress gonadal and adrenal androgens (Targeted Androgen Pathway Suppression, TAPS clinical trial). The method was validated by correlating the results obtained with a hydroxylamine derivatization procedure coupled with tandem mass spectrometry using selected reaction monitoring that was conducted in an independent laboratory.

Abstract 804: Disseminated tumor cell heterogeneity and dormancy in prostate cancer

Prostate cancer (PCa) can remain in the bone marrow for a prolonged period of time (&gt;5 years) while the patient shows no evidence of disease before the cancer eventually recurs. Dormant cancer cells can be detected in bone, the principal metastatic site of PCa, and these bone-homing cancer cells are known as disseminated tumor cells (DTC). Little information is available on the heterogeneity and dormancy of DTC in PCa. In this study, we isolated and compared the gene expression profile of individual DTC (n=45) from the bone marrow of 4 PCa patients with no evidence of disease and 5 patients with advanced disease. Using principle component analysis and cluster analysis of the 1000 most variable genes, we determined the heterogeneity of the DTC population within each patient. To identify a dormancy signature from DTC in the bone marrow and primary PCa cells, we carried out two gene expression analyses: DTC in patients with no evidence of disease vs. those with advanced disease, and primary PCa tissues from patients with a short vs. long dormancy period post radical prostatectomy (8-86 months). Genes associated in other cancers with cellular senescence, cell-cycle inhibition, and dormancy were analyzed. Candidate genes from both gene expression arrays were validated at the protein level by a tissue microarray consisting of 64 primary PCa cases that recurred after either a short or long dormancy period post radical prostatectomy (6-121 months).

The identification of heterogeneous gene signatures in DTC and novel proteins that promote dormancy will guide the development of possible biomarkers and therapeutic targets to prevent PCa recurrence, possibly by either eliminating DTC or inhibiting their escape from dormancy.

Citation Format: Hung-Ming Lam, Lisly Chéry, Ilsa Coleman, Bryce Lakely, Sandy Larson, Roger Coleman, Lisha Brown, Kathy Doan, Jennifer Noteboom, Xiaotun Zhang, Lawrence True, Peter Nelson, Bruce Montgomery, Paul Lange, Linda Snyder, Robert Vessella, Colm Morrissey. Disseminated tumor cell heterogeneity and dormancy in prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 804. doi:10.1158/1538-7445.AM2013-804

Abstract 305: The biological and molecular characterization of clinically relevant prostate cancer xenograft lines (LuCaP series), including responses to therapy

Introduction:

Prostate cancer (PCa) is a heterogeneous disease, which results in an unpredictable and varied response to therapy. A limitation in unraveling the complexities of PCa and developing / evaluating novel therapeutic strategies has been the lack of pre-clinical models that closely replicate this heterogeneity. To overcome this limitation we have established over 3 dozen PCa xenograft lines (LuCaP series).

Methods:

Characterization of the xenograft lines derived from PCa primaries and metastases includes: (a) growth properties, (b) expression of 45 biomarkers by immunohistochemistry (IHC), (c) gene expression, (d) copy number gains and losses, (e) expression of the androgen receptor (AR) and its splice variants, (f) bone response (i.e. osteoblastic, osteolytic or mixed), and (g) response to therapy, i.e. androgen ablation, docetaxel and anti-IGF-1R.

Results:

Forty distinct xenograft lines comprise the current LuCaP panel. Four are neuroendocine, 12 are castration resistant (CR) sublines and 7 are abiraterone or MDV-3100 resistant sublines. Comprehensive characterization studies have been done on 24 lines. All lines histologically resemble the originating clinical specimen. Unsupervised gene expression array clustering analyses revealed (a) association between the xenograft and the originating clinical specimen, (b) pairing of androgen-sensitive lines with their CR sublines, (c) a distinction between adenocarcinoma and neuroendocrine phenotypes and (d) insignificant drift over a 2-5 year period of serial passage. Biomarker expression is quite heterogeneous and in most cases, protein expression correlated well with gene expression.

Importantly, 7 LuCaP models elicit an osteoblastic reaction in the bone, 5 models are PTEN negative, and 8 lines have the TMPRSS2:ERG fusion. The xenograft lines express different levels of AR with some expressing AR splice variants.

Heterogeneity was also observed in responses to therapy; prolonged survival (PS) following androgen ablation or docetaxel treatment ranged from 1 - 7 fold. Interestingly, LuCaP 86.2, expressing predominantly ARv567es, was among the least responsive to androgen ablation (PS 1.1) whereas it is one of the most responsive to docetaxel (PS &gt;4). Several novel anti-androgen therapies are currently under investigation as individual agents and in combination; heterogeneous responses are being observed. To explore mechanisms of resistance, we are also maintaining sublines that developed resistance to abiraterone and MDV-3100.

Conclusions: These LuCaP PCa xenograft lines are highly diverse and clinically relevant models to study PCa biology and to evaluate new treatment modalities. The diversity of phenotypes and responses to therapy most importantly suggests that misleading conclusions can be drawn from the use of only one or two models in preclinical evaluations.

Citation Format: Holly Nguyen, Eva Corey, Colm Morrissey, Peter Nelson, Xiaotun Zhang, Martine Roudier, Stephen Plymate, Lawrence True, Celestia Higano, Robert Montgomery, Paul Lange, Robert Vessella. The biological and molecular characterization of clinically relevant prostate cancer xenograft lines (LuCaP series), including responses to therapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 305. doi:10.1158/1538-7445.AM2013-305

Perceived stress and risk of adult-onset asthma and other atopic disorders: a longitudinal cohort study

BACKGROUND

Psychological stress can affect airway inflammatory response to irritants and allergens, but the importance of stress in the etiology of adult-onset respiratory and dermatologic allergic disorders remains unclear. We aim to address the relationship between perceived stress and the risk of adult-onset asthma, allergic rhinitis, atopic dermatitis, and asthma/bronchitis medication.

METHODS

Participants (n = 9785) from the Copenhagen City Heart Study, Denmark, free of atopic disorders at baseline in 1981-1983 were asked questions on stress intensity and frequency. They were followed for first-time asthma hospitalization in nationwide registers until 2010, with < 0.1% loss to follow-up. Objective measures of lung function allowed for thorough adjustment for confounding and prevented ambiguity between diagnosis of asthma and chronic obstructive lung disease. Daily intake of asthma/bronchitis medication and incidence of asthma, allergic rhinitis, and atopic dermatitis were assessed by self-report after 10 years of follow-up in 5648 persons.

RESULTS

Perceived stress was associated with atopic disorders in a dose-dependent manner (P(trend)  < 0.001). High vs low stress was associated with higher risk of self-reported asthma incidence (OR = 2.32; 95% CI: 1.47-3.65), daily intake of asthma/bronchitis medication (OR = 2.26; 95% CI: 1.42-3.58), first-time asthma hospitalization (HR = 2.01; 95% CI: 1.41-2.86), allergic rhinitis (OR = 1.64; 95% CI: 0.99-2.72), and atopic dermatitis (OR = 1.75; 95% CI: 1.11-2.77). The associations were similar for smokers and nonsmokers.

CONCLUSIONS

Stress is strongly associated with asthma incidence and hospitalization, use of asthma medication as well as with allergic rhinitis and atopic dermatitis in adults.

Abstract C34: The biological and molecular characterization of 28 unique prostate cancer xenograft lines (LuCaP series), including responses to therapy

Introduction: Prostate cancer (PCa) is a heterogeneous disease which results in an unpredictable and wide range of responses to therapy. A significant limitation in unraveling the complexities of PCa and developing / evaluating novel therapeutic strategies is the lack of pre-clinical models that closely replicate the diversity of the disease seen in man. To overcome this limitation we have established over 2 dozen PCa xenograft lines (LuCaP series). This poster will provide a summary of the biological and molecular characterization of nearly all of these xenograft lines including their responses to therapy.

Methods: Characterization of the xenograft lines derived from primary PCa and PCa metastases includes: (a) basic histology, (b) serum PSA levels, (c) tumor doubling time, (d) expression of 38 biomarkers by immunohistology (IHC), (e) oligo array profiles, (f) expression of the androgen receptor (AR) and its splice variants, (g) bone response, and (h) response to therapy, i.e. androgen ablation, docetaxel and anti-IGF-1R.

Results: Of the 28 derived LuCaP xenograft lines, 24 are adenocarcinoma and 4 are neuroendocrine. Our results show that all lines histologically resemble the originating clinical specimen. Unsupervised gene expression array clustering analyses revealed (a) association between the xenograft and the originating clinical specimen, (b) pairing of androgen-sensitive lines with their castration-resistant offspring, (c) a distinction between adenocarcinoma and neuroendocrine phenotypes and (d) that gene expression profiles were not significantly altered by continuous passage in vivo for 2-8 years.

Importantly, seven of our models elicit an osteoblastic reaction in the bone, five models are PTEN negative, eight lines have the TMPRSS2:ERG fusion, and there are eight matched pairs of androgen-sensitive and castration-resistant xenografts.

As in the clinical scenario, the xenograft lines display considerable diversity. They express variable amounts of PSA (range from 0-1000 ng/ml/1 g), different levels of AR and express an AR splice variant after castration. IHC revealed considerable heterogeneity in all biomarkers evaluated. In most cases protein expression correlated well with gene expression.

Heterogeneity was also observed in responses to therapy; prolonged survival (PS) following androgen ablation or docetaxel each ranged from 1 - 7.3 fold. Interestingly, LuCaP 86.2, expressing predominantly ARv567es, was among the least responsive to androgen ablation (PS 1.1) whereas it is one of the most responsive to docetaxel (PS &gt;4). Several novel anti-androgen therapies are currently under investigation.

Conclusions: These 28 LuCaP PCa xenograft lines are highly diverse and clinically relevant models to study PCa biology and evaluate new treatment modalities. The diversity of phenotypes and responses to therapy most importantly suggests that misleading conclusions can be drawn from the use of only one or two PCa models in preclinical evaluations. Use of multiple models is extremely important in the evaluation of new therapeutic strategies, especially those targeting specific pathways.

Citation Format: Holly Nguyen, Martine Roudier, Lawrence True, Robert Vessella, Eva Corey, Colm Morrissey, Peter Nelson, Xiaotun Zhang, Stephen Plymate, Celestia Higano, Paul Lange. The biological and molecular characterization of 28 unique prostate cancer xenograft lines (LuCaP series), including responses to therapy [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr C34.

Abstract B31: Establishing the use of genomic profiling on rare prostate cancer disseminated tumor cells

Objective: Dissemination of prostate cancer tumor cells remains a critical challenge in understanding disease progression and effective long-term treatment of patients. Disseminated tumor cells (DTCs) from bone marrow are resistant to chemotherapy and radiation, and represent a potential long-lived source for lethal metastases. Quantification of disseminated and circulating tumor cells provides promise as a novel diagnostic in measuring tumor burden and assessing the risk of relapse. However, very limited knowledge exists about the biology of these rare cells, including the genomic aberrations associated with clinical outcome.

Methods: DTCs are immunomagnetically enriched from bone marrow aspirates, then individually captured under the microscope based on immunofluorescent staining of EpCaM cell surface molecules. We have established use of whole genome amplification and high-density SNP-CGH arrays to genomically profile rare DTC populations (n=2-25 cells). Using Fused Lasso and Nexus Copy Number software, we quantify and characterize copy number alterations and loss-of-heterozygosity regions among samples isolated from 58 patients taken at the time of radical prostectomy and from 13 patients with advanced, metastatic or lethal prostate cancer. We classify DTC aberrations by tumor stage and compare to those aberrations identified in primary and metastatic tumors. Regions of interest are validated using a highly sensitive quantitative real-time PCR assay. In addition, we have completed extensive optimization of analysis parameters to handle the increased probe variation associated with low input DNA quantity and whole genome amplification.

Results: DTCs isolated at the time of radical prostatectomy from early stage prostate cancer patients are generally heterogeneous and are marked with limited focal aberrations. Focal deletions of less than 100 kb are frequent events in these samples, as are focal gains of less than 500 kb, albeit less frequently. While many of these focal copy number changes are identified in regions of common copy number variation (CNV) within the population, a considerable number are rare and unique to DTCs. Cancer-specific alterations are observed in members of the cadherin family and transcription factors SIX3, SOX4, SOX17 and GATA6. Because most abberations are patient-specific, bioinformatic analysis is used to illuminate commonly altered biological pathways. In contrast, DTCs from patients with advanced stages of prostate cancer typically show frequent and large (&gt;1 Mb) clonal amplifications and deletions, suggesting a high degree of genomic instability that is common among these patients. Aberrant regions that are uniquely identified in DTCs from patients with advanced, metastatic and castrationresistant prostate cancers include gain of 1q43–q44 and 1q31.3–q41. In addition, several regions were found to be recurrent among at least 25% of metastatic tumors and DTCs from advanced stages, including in order of prevalence: +8q, −8p, +9q, −13, −22, −16q, −7q, −6q13–q22.31, +3q24–q26.1, +11q13.2–13.4, −17p13.3–p12 and +2p16.3–p16.2.

Conclusions: We have established methods and quality control measures for genome-wide profiling of rare cell populations. These methods will be functionally useful to gain a new understanding of the genomic aberrations that drive DTC dissemination, dormancy, and metastatic reactivation in prostate cancer.

Citation Format: Jamie R. Schoenborn, Jing Xia, Sandy Larson, Lisha Brown, Colm Morrissey, Paul Lange, Peter S. Nelson, Robert L. Vessella, Min Fang. Establishing the use of genomic profiling on rare prostate cancer disseminated tumor cells [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr B31.

Carcinoembryonic antigen in the CSF of cancer patients--the value of intrathecal synthesis and correlation with IgA-diffusion dynamics

OBJECTIVE

The diagnostic impact of carcinoembryonic antigen (CEA) was evaluated in serum and CSF of cancer and control patients.

METHODS

97 analyses of CEA in CSF and serum from 83 cancer patients were compared with 41 cases without malignancy. CEA diffusion dynamics were evaluated with IgA CSF/serum quotients (Q IgA). Intrathecal synthesis of CEA was analysed both by calculating an index Q CEA/Q IgA and within the IgA-diagram.

RESULTS

In 73 samples without synthesis of IgA or CEA, both quotients correlated well with a mean Q CEA/Q IgA of 1.1 (95% CI 0.97-1.2). The Q CEA/Q IgA was significantly higher in metastasizing adenocarcinomas than in controls or other malignancies. In leptomeningeal disease from adenocarcinoma, Q CEA/Q IgA was significantly higher than in controls, while patients with CNS and/or bone metastases had intermediate values. The sensitivity to detect leptomeningeal disease was 91% and 69% for brain metastases. Q CEA/Q IgA and CEA synthesis assessed with the IgA diagram were equally sensitive.

CONCLUSIONS

Evaluation of CEA in the IgA diagram is feasible and of clinical value. The consideration of intrathecal CEA synthesis correlates better with the clinical status than absolute CSF-CEA or the correlation with albumin.

Abstract 3242: The molecular and biological characterization of 25 unique prostate cancer xenograft lines, including response to therapy

Introduction: Prostate cancers (PCa) exhibit a wide range of molecular and biological profiles. In concert with this heterogeneity, there is a wide spectrum of responses to therapy. One of the significant limitations in unraveling the complexities of PCa and designing/evaluating novel therapeutic strategies has been the lack of pre-clinical models that closely replicate the diversity seen in man. To overcome this limitation we have developed 25 unique PCa xenograft lines (LuCaP series) where the initiating implants were derived from primary tumors, soft-tissue metastases and bone metastases. This presentation will provide details of a comprehensive molecular and biological characterization of these lines, including their responses to therapy.

Methods: Tumors were obtained either from radical prostatectomies or from our rapid autopsy program, which is designed specifically for the acquisition of metastatic foci. Tumor pieces were implanted into male, immune compromised mice. Characterization involves: (a) quantification of serum PSA levels, (b) basic histology, (c) tumor doubling time, (d) a panel of &gt;15 biomarkers assessed by immunohistochemistry, (e) gene expression array profiles, (f) chromosomal losses and gains, (g) expression of the TMPRSS2:ERG fusion gene, (h) presence of the androgen receptor (AR) and its splice variants, (i) bone remodeling perturbations associated with tumor growth in bone, and (j) response to therapy, including androgen ablation and docetaxel.

Results: Overall, 18% of the attempts to establish xenografts were successful resulting in 25 lines. As in the clinical scenario, these xenografts display a wide range of characterization profiles. While most are adenocarcinomas, 3 are neuroendocrine and all histologically resemble the originating clinical specimen. PSA serum levels can reach into the low thousands of ng/ml for a 1 g tumor. AR gene and protein expression is highly variable and &gt;50% of the lines express a constitutively active AR splice variant. The gene expression profiles show multiple clustering patterns that include a close association of the xenograft with the clinical specimen, pairing of androgen dependent lines with their castrate-resistant offspring and a distinction between adenocarcinoma and neuroendocrine histologies. Five of the lines are PTEN negative and 9 express the TMPRSS2:ERG gene fusion. The bone remodeling response ranges from osteoblastic to lytic. Responses to androgen ablation and docetaxel range from long duration to no response.

Conclusions: These 25 LuCaP PCa xenograft lines provide a highly diverse, yet clinically relevant, panel for the study of PCa biology. This diversity most importantly suggests that misleading conclusions can be drawn from use of only one or two PCa models. This is extremely important in the evaluation of new therapeutic strategies, especially those that target specific pathways.

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 3242.

Abstract 3302: Profiling prostate cancer metastases

Introduction: Prostate cancer (PCa) metastasizes to a number of sites, however, it has a propensity to metastasize to bone. There is considerable variation in sites of metastases, the phenotype of metastases, and bone response in PCa. Our objective was to detail the behavior of PCa metastases in a large cohort of patients who have died of PCa.

Methods: Tissue samples used in this study were obtained from seventy patients who had died from advanced PCa and who underwent a rapid autopsy, which was performed under the aegis of the Prostate Cancer Donor Program at the University of Washington. We evaluated the clinical history, sites of metastasis, pathology, biomarker expression and bone response for all 70 patients. We used laser capture microdissection to isolate mRNA from liver, lymph node and bone metastases and performed expression analyses on AgilentTM Oligo Arrays (n=32). Tissue microarrays were used to determine the number of neuroendocrine metastases, androgen receptor positivity, androgen-associated protein expression, and PCa proliferation rates (Ki-67) from 42 patients. Histomorphometry was used to evaluate bone response in ∼20 predetermined bone biopsy sites from 50 of the patients.

Results: PCa bone metastases occurred in 90% of our patients that died of PCa. Additionally, the majority of bone metastases were predominantly osteoblastic 71%, with 20% predominantly osteolytic and 9% with a mixed or no bone response. The predominant non-bone sites were lymph nodes, liver, lung and adrenal glands respectively. Seven of 42 patients had metastases with a neuroendocrine phenotype. Nuclear androgen receptor expression was high in bone and low in liver metastases and the correlation between nuclear AR and cytoplasmic PSA was 0.49. Proliferation rates were low in normal prostate increasing in Gleason 3 through 4, and higher in metastases. In a preliminary expression analysis we observed significantly higher expression of CD302, ZNF329, and TMEM79 in the PCa bone metastases compared to soft tissue metastases. Interestingly, bone histomorphometry revealed that the number of TRAcP positive osteoclasts was halved in bone cores from patients treated with bisphosphonates (n=459) compared to bone cores from non-bisphosphonate treated patients (n=284) (p=0.0003).

Conclusions: The heterogeneity of PCa metastases both within and between patients is a considerable obstacle in determining the appropriate treatment regime for each individual. Our data highlight these differences, while suggesting patients may be grouped into cohorts with consistent molecular signatures and clinical outcomes.

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 3302.