Alterations in small RNA profiles in liver following a subchronic exposure to a low-dose pesticide mixture in Sprague-Dawley rats

Small RNAs have emerged as a promising new type of biomarker to monitor health status and track the development of diseases. Here we report changes in the levels of small RNAs in the liver of rats exposed to a mixture of six pesticides frequently detected in foodstuffs (azoxystrobin, boscalid, chlorpyrifos, glyphosate, imidacloprid and thiabendazole). Multivariate analysis with OPLS-DA methods showed that small RNA profiles can discriminate samples from pesticide treated rats from their concurrent controls. A total of 9 miRNAs were found to have their levels altered in the liver of the pesticide-treated rats in comparison to the controls, which included 7 that were downregulated (miR-22-5p, miR-193a-3p, miR-32-5p, miR-33-5p, miR-122-5p, miR-22-3p, miR-130a-3p) and 2 that were upregulated (miR-486-5p, miR-146a-5p). These miRNAs were predicted to regulate genes, which were found to have their expression altered by the pesticide mixture and have known health implications in the regulation of hepatic metabolism. This supports and extends our recent conclusions that high- throughput 'omics' analyses can reveal molecular perturbations, which can potentially act as sensitive and accurate markers of health risks arising from exposure to environmental pollutants such as pesticides.

Clinical Remission of Sight-Threatening Non-Infectious Uveitis Is Characterized by an Upregulation of Peripheral T-Regulatory Cell Polarized Towards T-bet and TIGIT

Background

Non-infectious uveitis can cause chronic relapsing and remitting ocular inflammation, which may require high dose systemic immunosuppression to prevent severe sight loss. It has been classically described as an autoimmune disease, mediated by pro-inflammatory Th1 and Th17 T-cell subsets. Studies suggest that natural immunosuppressive CD4⁺CD25⁺FoxP3⁺ T-regulatory cells (Tregs) are involved in resolution of inflammation and may be involved in the maintenance of clinical remission.

Objective

To investigate whether there is a peripheral blood immunoregulatory phenotype associated with clinical remission of sight-threatening non-infectious uveitis by comparing peripheral blood levels of Treg, Th1, and Th17, and associated DNA methylation and cytokine levels in patients with active uveitic disease, control subjects and patients (with previously active disease) in clinical remission induced by immunosuppressive drugs.

Methods

Isolated peripheral blood mononuclear cells (PBMC) from peripheral blood samples from prospectively recruited subjects were analyzed by flow cytometry for CD3, CD4, FoxP3, TIGIT, T-bet, and related orphan receptor γt. Epigenetic DNA methylation levels of FOXP3 Treg-specific demethylated region (TSDR), FOXP3 promoter, TBX21, RORC2, and TIGIT loci were determined in cryopreserved PBMC using a next-generation sequencing approach. Related cytokines were measured in blood sera. Functional suppressive capacity of Treg was assessed using T-cell proliferation assays.

Results

Fifty patients with uveitis (intermediate, posterior, and panuveitis) and 10 control subjects were recruited. The frequency of CD4⁺CD25⁺FoxP3⁺ Treg, TIGIT⁺ Treg, and T-bet⁺ Treg and the ratio of Treg to Th1 were significantly higher in remission patients compared with patients with active uveitic disease; and TIGIT⁺ Tregs were a significant predictor of clinical remission. Treg from patients in clinical remission demonstrated a high level of in vitro suppressive function compared with Treg from control subjects and from patients with untreated active disease. PBMC from patients in clinical remission had significantly lower methylation levels at the FOXP3 TSDR, FOXP3 promoter, and TIGIT loci and higher levels at RORC loci than those with active disease. Clinical remission was also associated with significantly higher serum levels of transforming growth factor β and IL-10, which positively correlated with Treg levels, and lower serum levels of IFNγ, IL-17A, and IL-22 compared with patients with active disease.

Conclusion

Clinical remission of sight-threatening non-infectious uveitis has an immunoregulatory phenotype characterized by upregulation of peripheral Treg, polarized toward T-bet and TIGIT. These findings may assist with individualized therapy of uveitis, by informing whether drug therapy has induced phenotypically stable Treg associated with long-term clinical remission.

Secondary polycythaemia in a Malay girl with homozygous Hb Tak

Hb Tak is one of more than 200 high affinity haemoglobin variants reported worldwide. It results from the insertion of two nucleotides (AC) at the termination codon, between codon 146 and codon 147 of the beta-globin gene [Beta 147 (+AC)]. Polycythaemia is the main clinical feature although affected carriers are usually asymptomatic and do not require intervention. Several case studies in this region have reported the co-inheritance of Hb Tak with Hb E, delta beta and beta thalassaemia with one case of homozygous Hb Tak in a Thai boy. In this case report, a cluster of haemoglobin Tak was found in a family of Malay ethnic origin. Cascade family screening was conducted while investigating a 4-year old girl who presented with symptomatic polycythaemia. She had 2 previous Hb analysis done, at 7-month and 2-year-old with the diagnosis of possible Hb Q Thailand and Homozygous Hb D, respectively. Both diagnosis did not fit her clinical presentations. She was plethoric, had reduced exercise tolerance as well as cardiomyopathy. Her parents were consanguineously married and later diagnosed as asymptomatic carriers of Hb Tak. Consequently, re-analysis of the girl's blood sample revealed a homozygous state of Hb Tak. In conclusion, high oxygen affinity haemoglobin like Hb Tak should be considered in the investigation of polycythaemic patients with abnormal Hb analyses. In this case, DNA analysis was crucial in determining the correct diagnosis.

DNA methylation profiles between airway epithelium and proxy tissues in children

AIM

Epidemiological studies of deoxyribonucleic acid (DNA) methylation in airway disease have largely been conducted using blood or buccal samples. However, given tissue specificity of DNA methylation, these surrogate tissues may not allow reliable inferences about methylation in the lung. We sought to compare the pattern of DNA methylation in blood, buccal and nasal epithelial cells to that in airway epithelial cells from children.

METHODS

Samples of blood, and buccal, nasal and airway epithelium were obtained from six children undergoing elective anaesthesia for adenotonsillectomy. DNA methylation was assessed at 450 000 5'-C-phosphate-G-3' (CpG) sites using the Illumina HumanMethylation450 array.

RESULTS

Eighteen samples from all sites were suitable for analysis. Hierarchical clustering demonstrated that the methylation profile in nasal epithelium was most representative of that in airway epithelium; the profile in buccal cells was moderately similar and that in blood was least similar.

CONCLUSION

DNA methylation in blood poorly reflects methylation in airway epithelium. Future epidemiological studies of DNA methylation and airway diseases should consider measurement of methylation either in buccal cells or, preferably, in nasal epithelial cells.

Double-balloon enteroscopy in Ireland in the capsule endoscopy era

BACKGROUND

The availability of double-balloon enteroscopy (DBE) and small bowel capsule endoscopy (SBCE) in Ireland has revolutionised our approach to the diagnosis and treatment of small bowel disorders.

AIMS

To evaluate the use of DBE in Ireland and to compare the diagnostic yield with and without prior SBCE in order to improve the efficiency of our resources for small bowel endoscopy.

METHODS

A retrospective comparison study of all DBEs performed between two centres, one with SBCE available, was undertaken. Information was obtained by review of endoscopy reports, referral letters, radiology reports and charts. A review of the SBCE database was undertaken to identify patients who had undergone SBCE prior to DBE.

RESULTS

A total of 242 DBE procedures were carried out between both centres. SBCE was performed prior to DBE in 20 % (n = 46). The overall diagnostic yield of DBE was 47 % (n = 115). There was a statistically significant difference in diagnostic yield between the DBE only and the DBE with prior SBCE groups 44 versus 61 %, respectively, p < 0.0001. There was also a significant difference in the DBE approach, with 73 % of procedures being anterograde in centre 1 versus 56 % in centre 2. A subgroup analysis of centre 1 data revealed a negative predictive value of 100 % and a positive predictive value of 74 % for SBCE when DBE findings were considered as a gold standard.

CONCLUSION

SBCE as a screening tool prior to DBE is extremely valuable and increases the diagnostic yield considerably as a consequence of a high negative predictive value.

BayMeth: improved DNA methylation quantification for affinity capture sequencing data using a flexible Bayesian approach

Affinity capture of DNA methylation combined with high-throughput sequencing strikes a good balance between the high cost of whole genome bisulfite sequencing and the low coverage of methylation arrays. We present BayMeth, an empirical Bayes approach that uses a fully methylated control sample to transform observed read counts into regional methylation levels. In our model, inefficient capture can readily be distinguished from low methylation levels. BayMeth improves on existing methods, allows explicit modeling of copy number variation, and offers computationally efficient analytical mean and variance estimators. BayMeth is available in the Repitools Bioconductor package.

Clinical implications of family history of prostate cancer and genetic risk single nucleotide polymorphism (SNP) profiles in an active surveillance cohort

OBJECTIVES

To explore the potential prognostic role of family history (FH) of prostate cancer and prostate cancer risk single nucleotide polymorphisms (SNPs) in patients undergoing active surveillance (AS) for prostate cancer. This is the first study to date, which has investigated the potential prognostic role of SNP profiles in an AS cohort

PATIENTS AND METHODS

FH data were collected from patients in the Royal Marsden Hospital AS study. In all, 39 prostate cancer-risk SNPs identified from published genome wide association studies (GWAS) were genotyped using the Sequenom Platform and TaqMan™ assays from available DNA. The cumulative genetic-risk scores for each patient were then calculated using the weighted effect estimated from previous GWAS (log-additive model). FH status and the genetic-risk scores were assessed against adverse outcomes in AS, time to treatment and adverse histology on repeat biopsy, using univariable and multivariable Cox regression models to address time to treatment; and binary logistic regression to address biopsy upgrade.

RESULTS

Of 471 patients, 55 (13.6%) had adverse histology on repeat biopsies and 145 (30.8%) had deferred treatment. On univariate analysis, there was no significant relationship between FH of prostate cancer in any degree of relation, and adverse histology or time to treatment. For risk score analyses, 386 patients' DNA was studied; and there was also no relationship found between the calculated genetic risk scores and adverse histology or time to treatment (P = 0.573 and P = 0.965, respectively). The retrospective study design and the few events were the main limitation of the study.

CONCLUSIONS

There is currently insufficient data to support the use of FH status or prostate cancer SNP profile risk scores as prognostic factors in AS and these should not be used to influence management decisions. As more genetic variants are discovered this may change and should be reassessed in multicentre AS cohorts.

Clinical implications of a prostate cancer risk SNP profile in two treatment cohorts

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Background: Prostate cancer (PCa) has a heritable risk and genome-wide association studies (GWAS) have so far identified 76 single nucleotide polymorphisms (SNPs) associated with PCa risk. Currently these SNPs have only been evaluated against overall PCa risk and several disease parameters. Their clinical utility remains undefined. We explore the potential prognostic role of the risk SNP profile in 2 PCa cohorts; Active Surveillance (AS) and androgen deprivation therapy (ADT). Methods: PCa patients at the Royal Marsden Hospital who consented for DNA analyses were eligible. 2 separate cohorts were identified; those undergoing AS and those receiving ADT. The risk SNPs were genotyped using Sequenom or Fluidigm platforms. The cumulative SNP risk scores for each patient were calculated by summing risk alleles for each loci using the weighted effect as estimated in previous studies (log-additive model). For the AS group, the risk scores were analysed against defined adverse outcomes in AS, including adverse histology on repeat biopsy and time to treatment, to determine their prognostic value. For the ADT group, the risk scores were assessed against time to relapse, defined by either biochemical relapse or evidence of progression on imaging. Results: In the AS group, 391 patients’ DNA were studied. 31% of those have since undergone treatment and 30% have histological upgrade on repeat biopsies. On univariate analysis, there was no significant relationship between the risk scores and biopsy upgrade or time to treatment (p>0.05). When analysing differences in outcomes between the higher and lower risk groups (top 25% and lowest 25% of the genetic risk distribution), there was again no relationship (p>0.05). In the ADT group, 567 patients’ DNA were studied. The mean duration of response was 30 months. No significant associations were found when risk scores were analysed as a continuous variable against time to relapse on ADT, or when analysing difference between the top and bottom 25% of the risk distribution (p>0.05). Conclusions: PCa SNP risk scores have not been shown to be prognostic factors in either AS or ADT. This is the first study analysing the potential prognostic role of the latest GWAS risk SNPs in PCa treatment cohorts.

Germline BRCA mutations are associated with higher risk of nodal involvement, distant metastasis, and poor survival outcomes in prostate cancer

PURPOSE

To analyze the baseline clinicopathologic characteristics of prostate tumors with germline BRCA1 and BRCA2 (BRCA1/2) mutations and the prognostic value of those mutations on prostate cancer (PCa) outcomes.

PATIENTS AND METHODS

This study analyzed the tumor features and outcomes of 2,019 patients with PCa (18 BRCA1 carriers, 61 BRCA2 carriers, and 1,940 noncarriers). The Kaplan-Meier method and Cox regression analysis were used to evaluate the associations between BRCA1/2 status and other PCa prognostic factors with overall survival (OS), cause-specific OS (CSS), CSS in localized PCa (CSS_M0), metastasis-free survival (MFS), and CSS from metastasis (CSS_M1).

RESULTS

PCa with germline BRCA1/2 mutations were more frequently associated with Gleason ≥ 8 (P = .00003), T3/T4 stage (P = .003), nodal involvement (P = .00005), and metastases at diagnosis (P = .005) than PCa in noncarriers. CSS was significantly longer in noncarriers than in carriers (15.7 v 8.6 years, multivariable analyses [MVA] P = .015; hazard ratio [HR] = 1.8). For localized PCa, 5-year CSS and MFS were significantly higher in noncarriers (96% v 82%; MVA P = .01; HR = 2.6%; and 93% v 77%; MVA P = .009; HR = 2.7, respectively). Subgroup analyses confirmed the poor outcomes in BRCA2 patients, whereas the role of BRCA1 was not well defined due to the limited size and follow-up in this subgroup.

CONCLUSION

Our results confirm that BRCA1/2 mutations confer a more aggressive PCa phenotype with a higher probability of nodal involvement and distant metastasis. BRCA mutations are associated with poor survival outcomes and this should be considered for tailoring clinical management of these patients.

A meta-analysis of genome-wide association studies to identify prostate cancer susceptibility loci associated with aggressive and non-aggressive disease

Genome-wide association studies (GWAS) have identified multiple common genetic variants associated with an increased risk of prostate cancer (PrCa), but these explain less than one-third of the heritability. To identify further susceptibility alleles, we conducted a meta-analysis of four GWAS including 5953 cases of aggressive PrCa and 11 463 controls (men without PrCa). We computed association tests for approximately 2.6 million SNPs and followed up the most significant SNPs by genotyping 49 121 samples in 29 studies through the international PRACTICAL and BPC3 consortia. We not only confirmed the association of a PrCa susceptibility locus, rs11672691 on chromosome 19, but also showed an association with aggressive PrCa [odds ratio = 1.12 (95% confidence interval 1.03-1.21), P = 1.4 × 10(-8)]. This report describes a genetic variant which is associated with aggressive PrCa, which is a type of PrCa associated with a poorer prognosis.

Germline BRCA1 mutations increase prostate cancer risk

BACKGROUND

Prostate cancer (PrCa) is one of the most common cancers affecting men but its aetiology is poorly understood. Family history of PrCa, particularly at a young age, is a strong risk factor. There have been previous reports of increased PrCa risk in male BRCA1 mutation carriers in female breast cancer families, but there is a controversy as to whether this risk is substantiated. We sought to evaluate the role of germline BRCA1 mutations in PrCa predisposition by performing a candidate gene study in a large UK population sample set.

METHODS

We screened 913 cases aged 36–86 years for germline BRCA1 mutation, with the study enriched for cases with an early age of onset. We analysed the entire coding region of the BRCA1 gene using Sanger sequencing. Multiplex ligation-dependent probe amplification was also used to assess the frequency of large rearrangements in 460 cases.

RESULTS

We identified 4 deleterious mutations and 45 unclassified variants (UV). The frequency of deleterious BRCA1 mutation in this study is 0.45%; three of the mutation carriers were affected at age 65 years and one developed PrCa at 69 years. Using previously estimated population carrier frequencies, deleterious BRCA1 mutations confer a relative risk of PrCa of ~3.75-fold, (95% confidence interval 1.02–9.6) translating to a 8.6% cumulative risk by age 65.

CONCLUSION

This study shows evidence for an increased risk of PrCa in men who harbour germline mutations in BRCA1. This could have a significant impact on possible screening strategies and targeted treatments.

Abstract 4495: Clinical implications of family history of prostate cancer in an active surveillance cohort

Background Prostate cancer (PCa) is one of the most heritable cancers and a positive family history (FH) of PCa increases risk to 1st degree relatives by over 2 fold. The search for causative genetic variants has led to genome-wide association studies, which have so far identified over 45 susceptibility loci associated with PCa. However, the clinical utility of FH status or PCa risk SNP profiles to predict disease progression or aggression is yet undefined. We explore their potential prognostic role in patients undergoing Active Surveillance (AS). Methods Those enrolled in the Royal Marsden Hospital AS study were eligible. FH was obtained using questionnaires. For those with missing/incomplete data, hospital records were used. Patients with positive FH were further stratified according to the involvement of 1st and/or 2nd degree relatives. For risk score analyses, DNA was genotyped using the Sequenom MassARRAY iPLEX platform and Taqman assays. The cumulative risk scores for each patient were calculated by summing risk alleles for each loci using the weighted effect as estimated in previous studies. FH status and the SNP risk scores were analysed separately against defined adverse outcomes in AS, including adverse histology on repeat biopsy and time to treatment, to determine their prognostic value. Results 439 patients were eligible for FH analyses. 31% of those have since undergone treatment and 13% have histological upgrade on repeat biopsies. On univariate analysis, there was no significant relationship between FH of PCa in any degree of relation, and biopsy upgrade or time to treatment. For risk score analyses, 391 patients’ DNA were studied. There was also no relationship between the calculated genetic risk scores and biopsy upgrade or time to treatment (p=0.57 and p=0.83 respectively). When analysing differences between the higher and lower genetic risk groups (defined as the top 25% and lowest 25% of the genetic risk distribution), there was again no relationship (p=0.85 and p=0.91 respectively). Conclusion FH status or currently known PCa SNP profile risk scores have not been shown to be prognostic factors and should not be used to influence decisions in AS. This is the first study analysing the implications of PCa risk SNPs in AS.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4495. doi:1538-7445.AM2012-4495

Abstract 3810: BRCA2 is a moderate penetrance gene contributing to young onset prostate cancer, but not disease over 65 years

The aetiology of prostate cancer (PrCa) is poorly understood. A family history of prostate cancer, particularly at a young age, is a strong risk factor for the disease, indicating that inherited factors are important in PrCa. To date, the strongest genetic risk factor for PrCa is a protein truncating mutation in BRCA2, Studies in breast/ovarian cancer families have estimated a risk of ∼5 fold in BRCA2 carriers. We previously estimated that 2.3% of PrCa cases diagnosed at ≤55 years harbour a BRCA2 mutation. PrCa in BRCA2 carriers has been shown to be more aggressive, with poorer survival.

To further evaluate the role of BRCA2 in PrCa predisposition we screened 1910 men with PrCa aged 36 to 86 years. Patients were recruited through the UKGPCS (UK Genetic Prostate Cancer Study Collaborators). The study was enriched for cases with an early age of onset (1639 men ≤65yrs) and/or positive family history of PrCa (271 men &gt;65 with at least 2 affected relatives with PrCa). We analyzed the entire coding region of the BRCA2 gene in 46 PCR fragments by using a high-throughput multiplex fluorescent heteroduplex detection system developed for the ABI3130 genetic analyser. After repeats and QC 32 samples were excluded from the analysis. Fragments were analyzed for peak shifts corresponding to putative mutations in Genemapper v4.0 (Applied Biosystems) by visual inspection and using Bionumerics (Applied Maths). All fragments with peak-shifts were Sanger sequenced to characterise the mutation and validated using re-PCR and Sanger sequencing.

We have identified 19 frameshift mutations, 3 in-frame deletions and 56 missense variants of uncertain significance (UV). Based on studies in breast/ovarian cancer families, most UVs and some in-frame deletions are likely to be neutral. All the carriers of frameshift mutations were affected at age ≤65 years, 12 patients had family history of prostate cancer and 9 patients had some family history of breast or ovarian cancer. The prevalence of mutations was 1.25 % (8/638) for cases diagnosed ≤55 years and 1.17 % (19/1620) for cases diagnosed ≤ 65 years. Based on the estimated frequency of BRCA2 mutations in the UK (0.16%) we estimate that mutations in the BRCA2 gene confer a risk of prostate cancer of approximately 7 fold by age 65 (close to previous estimates from breast-ovarian cancer families), corresponding to an absolute risk of ∼4% by age 65.

As targeted treatments using drugs such as PARP inhibitors have shown activity in women with cancer who have BRCA mutations and as mutation tests become cheaper, there would be a rationale for testing young onset PrCa cases for BRCA2 mutations to offer such targeted treatments.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3810. doi:10.1158/1538-7445.AM2011-3810

Identification of a novel prostate cancer susceptibility variant in the KLK3 gene transcript

Genome-wide association studies (GWAS) have identified more than 30 prostate cancer (PrCa) susceptibility loci. One of these (rs2735839) is located close to a plausible candidate susceptibility gene, KLK3, which encodes prostate-specific antigen (PSA). PSA is widely used as a biomarker for PrCa detection and disease monitoring. To refine the association between PrCa and variants in this region, we used genotyping data from a two-stage GWAS using samples from the UK and Australia, and the Cancer Genetic Markers of Susceptibility (CGEMS) study. Genotypes were imputed for 197 and 312 single nucleotide polymorphisms (SNPs) from HapMap2 and the 1000 Genome Project, respectively. The most significant association with PrCa was with a previously unidentified SNP, rs17632542 (combined P = 3.9 × 10⁻²²). This association was confirmed by direct genotyping in three stages of the UK/Australian GWAS, involving 10,405 cases and 10,681 controls (combined P = 1.9 × 10⁻³⁴). rs17632542 is also shown to be associated with PSA levels and it is a non-synonymous coding SNP (Ile179Thr) in KLK3. Using molecular dynamic simulation, we showed evidence that this variant has the potential to introduce alterations in the protein or affect RNA splicing. We propose that rs17632542 may directly influence PrCa risk.

Enteropathy associated T-cell lymphoma resulting in restrictive cardiomyopathy and mimicking myocardial infarction

A 64-year-old woman was referred with a short history of abdominal pain, anorexia and weight loss. Investigations revealed a probable enteropathy associated T-cell lymphoma (EATL). Further investigations revealed evidence of what appeared to be a myocardial infarction. After going through laparoscopy to obtain diagnostic tissue, the patient developed cardiogenic shock which proved refractory to medical therapy. Postmortem examination revealed diffuse abdominal lymphoma consistent with EATL. Surprisingly, there was extensive infiltration of the myocardium. This report demonstrates an unusual pathology resulting from EATL and discusses the limited evidence relating to cardiac involvement of this disease.

Abstract 3862: Identification of a novel genetic variant in the KLK3 gene which predisposes to prostate cancer

Prostate cancer (PrCa) is the commonest solid tumour in men in developed countries. To identify common PrCa susceptibilility alleles, we conducted a multistage genome-wide association study (GWAS). In the first stage (stage 1) 541,129 SNPs were genotyped using the Illumina Infinium platform in 1,854 PrCa cases with clinically detected PrCa diagnosed at &lt;60 years or a family history of disease, and 1,894 population screened controls with low (&lt; 0.5ng/ml) prostate specific antigen (PSA) level from the UK. We identified 7 novel PrCa susceptibility loci (P=2.2×10−8 to P=8.1×10−29) one of which contains a strong candidate susceptibility gene KLK3 which codes for PSA. PSA is widely used as a biomarker for PrCa detection and disease monitoring. The tag-SNP in this region, rs2735839, was associated with both PrCa disease (P=1.33×10−20) and with PSA level (P =6× 10−8). To refine the association of PrCa with variants in this region we imputed genotypes for SNPs that were not in our GWAS study, using the Mach program and the HapMap 2 CEU population as a reference panel. Among SNPs in the KLK3 region, the strongest evidence for association with PrCa cancer was observed for rs17632542, (P =5.9×10−26), a SNP not typed in the GWAS. We genotyped this novel SNP in our stage 1 (as above) and an additional stage2 sample set of 3650 PrCa cases and 3940 controls from the UK and Australia, not selected for PSA level, using Taqman assay and ABIPrism 7900HT sequence detection system. rs1763542 showed stronger evidence of association than the original tag-SNP in both stages (stage 2 P=2×10−5, overall P=3.2×10−31). Whereas rs2735839 is intergenic between the KLK3 and KLK2 genes, rs17632542 is a non-synonymous coding SNP in the KLK3 gene causing an Ile to Thr substitution at aa179. We conclude that this SNP more strongly associated with PrCa then other known SNPs in the KLK3 region, and is a strong candidate for a causative variant influencing PrCa risk.

Acknowledgements: This study was funded by Cancer Research UK, The Prostate Cancer Research Foundation, and NIHR support to the Biomedical Research Centre.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

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 3862.

Haematological support during peg-interferon therapy for HCV-infected haemophiliacs improves virological outcomes

Hepatitis C virus-infected haemophiliacs are traditionally under represented in international treatment studies thus data assessing response to pegylated-interferon (peg-IFN) and ribavirin (RBV) in HCV mono-infected or HCV/HIV co-infected haemophiliacs are few. Since 2001, 37 haemophiliac patients have received peg-IFN and RBV according to centre-based investigator initiated protocols. Primary end points were: early virological response (EVR); end of treatment response (EOTR) and sustained virological response (SVR). An intention-to-treat analysis was used. Secondary end points were adverse events, haemopoietic stem cell growth factor use, therapy discontinuations and dose reductions. Hepatitis C virus mono-infection group (Mono-I) numbered 20 (60% genotype 1). HCV/HIV co-infected group (Co-I) numbered 17 (59% genotype 1/4). Primary end points were: EVR 76%, EOTR 70% and SVR 43%. Comparison of Mono-I to Co-I demonstrated: EVR rates of 70% and 82%, respectively; EOTR rates of 65% and 76%, respectively, and SVR rates of 35% and 53%, respectively. SVR rates genotype 1/4 group - 17% (Mono-I) vs. 30% (Co-I); SVR rates genotype 2/3 group - 63% (Mono-I) vs. 86% (Co-I). Therapy discontinuations: six of 20 (30%) Mono-I vs. three of 17 (18%) Co-I. Dose reductions: two of 20 (10%) Mono-I vs. zero of 17 Co-I. Haematological support factor use: one of 20 (5%) Mono-I vs. four of 17 (23.5%) Co-I. Virological outcomes to peg-IFN and RBV in HCV-infected haemophiliacs are comparable to published data relating to other HCV-infected cohorts. Good virological outcomes can be achieved in HIV co-infected haemophiliacs particularly when growth factors are used to facilitate full dosing of peg-IFN and RBV.

Comparable kinetics of myeloablation between fludarabine/full-dose busulfan and fludarabine/melphalan conditioning regimens in allogeneic peripheral blood stem cell transplantation

Fludarabine was utilized in the conditioning regimen of 30 adult patients undergoing an allogeneic hematopoietic stem cell transplant. In 18 patients it was combined with full-dose busulfan (FluBu) as a myeloablative regimen and in 12 cases with melphalan (FluMel) as a reduced intensity conditioning (RIC) regimen. Patients in the FluBu group were younger than in the FluMel group (P=0.03). Of 30 patients, 24 received peripheral blood stem cells (PBSC) whereas six patients in the FluBu group received bone marrow cells. The hematological toxicity of each regimen was evaluated by analyzing the kinetics of the neutropenia induced by preparative regimens and the time to recovery of the absolute neutrophils count (ANC) and platelets post transplantation. In PBSC transplants, the median day of severe neutropenia (<500 ANC/microl) occurred on day +6 after the FluBu regimen and on day +3 after FluMel (P=ns), whereas both groups had a duration of severe neutropenia of 9 days and a comparable time for ANC and platelet engraftment. Extra-hematological toxicities were also comparable in the two groups. These findings suggest that the hematological and extra-hematological toxicities induced by fludarabine/full-dose i.v. busulfan are similar to those induced by a standard RIC regimen such as fludarabine/melphalan.

Prolonged responses after autologous stem cell transplantation in African-American patients with multiple myeloma

Multiple myeloma (MM) has a double incidence in African-American (AA) than in non-AA patients and previous studies have shown a higher mortality in the former patient population. Here, we retrospectively analyzed the results of autologous stem cell transplantation (ASCT) in 38 AA and 32 non-AA consecutive patients. The two groups were comparable at diagnosis for age, stage of the disease, cytogenetic abnormalities, beta(2) microglobulin and albumin blood levels, and plasma cell marrow infiltration. The rates of complete and partial response observed in AA and non-AA patients after induction chemotherapy (9 and 42 vs 13 and 33%) and at 2 months (31 and 25 vs 30 and 20%) following ASCT were similar. At 6 months after ASCT, a greater relapse rate was observed in non-AA patients (P=0.009). At a median follow-up of 26 months, AA patients had a greater event-free survival (P=0.02) than non-AA patients, whereas overall survival was comparable in the two groups. The initial finding that AA patients with MM, compared to non-AA patients, had more prolonged responses and comparable survival after ASCT suggests that intensified chemotherapy is equally effective in patients of various ethnicities.

Identification of unique hepatitis C virus quasispecies in the central nervous system and comparative analysis of internal translational efficiency of brain, liver, and serum variants

Reports of cerebral dysfunction in chronic hepatitis C virus (HCV) infection have led to the suggestion that HCV may infect the central nervous system (CNS). We used reverse transcription-PCR, cloning, and sequencing to define quasispecies for the HCV internal ribosomal entry site (IRES) and hypervariable region 1 (HVR1) in autopsy-derived brain, liver, lymph node, and serum samples. There was evidence of tissue compartmentalization of sequences in the brain in two patients, with between 24 and 55% of brain-derived IRES sequences absent from the serum, and significant phylogenetic and phenetic clustering of the brain and lymph node HVR1 sequences. The IRES initiates cap-independent translation of the viral polyprotein. Two unique brain-derived IRES mutations (C(204)-->A and G(243)-->A), which have previously been associated with lymphoid replication and altered translational efficiency in cell culture, were found in one patient. We used a dicistronic reporter vector to test whether brain-derived variants showed altered IRES-mediated translational efficiency, which might favor CNS infection. The translational efficiencies of the brain-derived IRES sequences were generally reduced compared to those of the master serum and liver sequences in rabbit reticulocyte cell lysates and two human cell lines, HuH7 (liver) and CHME3 (microglial). The C(204)-->A and G(243)-->A mutations showed preserved translational efficiency in HuH7 cells but reduced efficiency in CHME3 cells. Our data provide evidence that the CNS is a site of HCV replication, consistent with the recent demonstration of negative-strand HCV RNA in brain, and suggest that IRES polymorphisms may be important as a viral strategy of reduced translation to favor latency in the CNS.

Anti-transglutaminase antibodies and the serological diagnosis of coeliac disease

Tissue transglutaminase (tTG) has recently been identified as the antigenic target recognised by anti-endomysial antibodies in patients with coeliac disease. In this study, an enzyme-linked immunosorbent assay (ELISA) is used to measure IgA, IgG and IgM antibodies to tTG in patients with coeliac disease and a variety of other inflammatory disorders; and is compared to the standard immunofluorescence test used to detect endomysial antibodies (EMA). In the samples tested, 3% control sera (n=146), 83% EMA-positive sera (n=29), 9% patients with Graves' disease (n=94), 12% antimitochondrial antibody-positive sera (n=53), 11% rheumatoid arthritis patients (n=53) and 22% systemic lupus erythematosus (SLE) patients (n=46) were positive for anti-tTG antibodies. In contrast, none of the controls, 1% of patients with Graves' disease, 2% antimitochondrial antibody-positive sera, 2% rheumatoid arthritis patients and none of the SLE patients were positive for EMA. Measurement of IgG or IgM antibodies to tTG was much less reliable than IgA anti-tTG antibody for the serological diagnosis of coeliac disease. The addition of calcium to the coating buffer improved the assay characteristics of the anti-tTG ELISA. However, the IgA anti-tTG ELISA, with and without calcium, performed less well than the standard EMA test used for the serological diagnosis of coeliac disease. In particular, the anti-tTG ELISA gave a higher rate of non-specific positive reactions.

Detection of replicative integrity in small colonic biopsies using the BrdUrd comet assay

The alkaline single-cell gel electrophoresis or comet assay is a relatively simple method of measuring DNA single-strand breaks and alkali-labile sites in individual cells. Previously, we have used a combination of this with bromodeoxyuridine labelling of DNA and immunolocalisation of the BrdUrd to show that DNA replicative integrity can be assessed in single cultured cells. This study demonstrates the application of the technique to single cells derived from small human colonic biopsies isolated at routine endoscopy. A high level of reproducibility within replicate comet slides and between comet slides prepared from various colonic sites within a single patient is shown. Preliminary results demonstrate that defects in replication can be detected in tumour and premalignant colonic tissue adjacent to the tumour, suggesting that alterations in replicative integrity are an early event in neoplasia, appearing in premalignant mucosal cells. This development deems the BrdUrd comet assay suitable as an ex vivo molecular end point that can be measured easily in tissue collected by biopsy at routine colonic endoscopy. Thus, the BrdUrd comet assay has the potential to facilitate trial investigations of diet- or environment-related factors that may affect replicative integrity in the colon and provides a novel biomarker for colon carcinogenesis.

Measurement of thyroid volume in children using a portable ultrasound machine: a technical note

The data on thyroid volume measurements that determines prevalence of goitre in children is very important for public health consideration as the presence of goitre in children effectively reflects the status of iodine deficiency disorders (IDD) in the general population. Ultrasound is an excellent modality to evaluate thyroid size. Local experience in using a portable ultrasound machine to measure thyroid volume is presented. The thyroid anatomy and techniques of ultrasound assessment are highlighted. Proper training of public health doctors to perform thyroid gland ultrasonography is crucial to ensure that the thyroid volume data collected would be more accurate and reliable for the planning of health programmes to eliminate IDD in the particular areas.

Evaluation of renal function following treatment with 5-aminosalicylic acid derivatives in patients with ulcerative colitis

BACKGROUND

A number of cases of nephrotoxicity have been reported in patients with inflammatory bowel disease taking oral 5-aminosalicylic acid (5-ASA).

AIM

To evaluate the effects of 9 months of therapy with mesalazine or olsalazine on renal function in patients with ulcerative colitis in remission.

METHODS

Forty patients with ulcerative colitis in complete remission for 6 months were randomized to either olsalazine (n=20) or mesalazine (n=20 for nine months). Thirty-six of the 40 patients were on prior salicylate therapy. Disease activity was the measure ofclinical efficacy and was assessed by the Harvey-Bradshaw Index (HBI). Laboratory efficacy measurements included glomerular filtration rate (GFR), microalbuminuria, urinary gluthathione S-transferase (GST) and serum C-reactive protein (CRP). Safety analysis consisted of documentation of adverse events and laboratory values.

RESULTS

There was no significant reduction in the GFR overall on therapy. The levels of GFR adjusted for baseline were similar in the two treatment groups after 3, 6 and 9 months. A significantly higher percentage of mesalazine-treated patients experienced drug related adverse events, all of a minor nature. The incidence of adverse events causing early withdrawal was similar in the two treatment groups.

CONCLUSION

Treatment with mesalazine or olsalazine for 9 months had no significant impact on GFR.

A double-blind placebo-controlled study of buspirone-stimulated prolactin release in non-ulcer dyspepsia--are central serotoninergic responses enhanced?

BACKGROUND

Dyspepsia is a common symptom for which an organic cause is found in only 40% of patients. When no cause is apparent and the dyspepsia is considered to be idiopathic, a diagnosis of non-ulcer dyspepsia is made. The pathophysiology of non-ulcer dyspepsia is poorly understood and numerous theories have been put forward, including a theory of enhanced central serotoninergic receptor sensitivity.

AIM

To determine the sensitivity of serotonin receptors in non-ulcer dyspepsia.

METHODS

Using a randomized, double-blind, placebo-controlled design, we compared buspirone (a serotonin type 1a partial agonist)-stimulated prolactin release in 50 patients and 59 healthy comparison subjects. Buspirone, 30 mg, or matching placebo was administered on two separate occasions and prolactin release over 180 min was monitored. Patients and healthy subjects received both treatments in random order, 1 week apart.

RESULTS

Overall, patients with non-ulcer dyspepsia had greater prolactin release in response to the buspirone challenge than the healthy comparison subjects, with differences most significant at 90 min following the challenge. Enhancement occurred in patients both with and without Helicobacter pylori infection. Female subjects, both patients and healthy volunteers, showed a greater response to buspirone than male subjects, and the augmentation of response observed in male and female patients was greater in females.

CONCLUSIONS

Patients with non-ulcer dyspepsia have enhanced central serotoninergic responses and such responses are independent of H. pylori infection. Blockade of such receptors might be an appropriate therapeutic strategy.

Olsalazine is not superior to placebo in maintaining remission of inactive Crohn's colitis and ileocolitis: a double blind, parallel, randomised, multicentre study

BACKGROUND AND AIMS

The benefit of 5-aminosalicylic acid therapy for maintenance of remission in Crohn's disease is controversial. The primary aim of this study was to evaluate the prophylactic properties of olsalazine in comparison with placebo for maintenance of remission in quiescent Crohn's colitis and/or ileocolitis.

METHODS

In this randomised, double blind, parallel group study of olsalazine versus placebo, 328 patients with quiescent Crohn's colitis and/or ileocolitis were recruited. Treatment consisted of olsalazine 2.0 g daily or placebo for 52 weeks. The primary end point of efficacy was relapse, as defined by the Crohn's disease activity index (CDAI) and by clinical relapse. Laboratory and clinical disease activity indicators were also measured. Safety analysis consisted of documentation of adverse events and laboratory values.

RESULTS

No differences in the frequency of termination due to relapse or time to termination due to relapse were noted between the two treatment groups (olsalazine 48.5% v placebo 45%) for either colitis or ileocolitis. The failure rate, defined as not completing the study, was significantly higher in olsalazine treated patients compared with placebo treated patients for the overall population (colitis and/or ileocolitis: olsalazine 65.4% v 53.9%; p=0.038). Similar failure rates were seen for patients with colitis. A significantly higher percentage of olsalazine treated patients experienced adverse gastrointestinal events. Drug attributed adverse events were reported more frequently in the olsalazine treated group with gastrointestinal symptoms being causally related to olsalazine treatment (olsalazine 40.7% v placebo 26.9%; p=0.010). Back pain was reported significantly more often by the placebo treated group. However, serious medical events did not differ between the two groups. Adverse events led to more early withdrawals in the olsalazine treated group than in the placebo treated group; thus average time in the study for patients in the olsalazine treatment group was significantly shorter than that of patients in the placebo group.

CONCLUSIONS

Patients treated with olsalazine were more likely to terminate their participation in the trial than those taking placebo. This difference was not related to relapse of disease, as measured by CDAI and clinical measures, but rather was due to the development of intolerable adverse medical events of a non-serious nature related to the gastrointestinal tract. The gastrointestinal related events in the olsalazine treated group may be due to the difference in gastrointestinal status at baseline which favoured the placebo treatment group.