Prediction of recurrence from metabolites and expression of TOP2A and EZH2 in prostate cancer patients treated with radiotherapy

BACKGROUND

The dual upregulation of TOP2A and EZH2 gene expression has been proposed as a biomarker for recurrence in prostate cancer patients to be treated with radical prostatectomy. A low tissue level of the metabolite citrate has additionally been connected to aggressive disease and recurrence in this patient group. However, for radiotherapy prostate cancer patients, few prognostic biomarkers have been suggested. The main aim of this study was to use an integrated tissue analysis to evaluate metabolites and expression of TOP2A and EZH2 as predictors for recurrence among radiotherapy patients.

METHODS

From 90 prostate cancer patients (56 received neoadjuvant hormonal treatment), 172 transrectal ultrasound-guided (TRUS) biopsies were collected prior to radiotherapy. Metabolic profiles were acquired from fresh frozen TRUS biopsies using high resolution-magic angle spinning MRS. Histopathology and immunohistochemistry staining for TOP2A and EZH2 were performed on TRUS biopsies containing cancer cells (n = 65) from 46 patients, where 24 of these patients (n = 31 samples) received hormonal treatment. Eleven radical prostatectomy cohorts of a total of 2059 patients were used for validation in a meta-analysis.

RESULTS

Among radiotherapy patients with up to 11 years of follow-up, a low level of citrate was found to predict recurrence, p = 0.001 (C-index = 0.74). Citrate had a higher predictive ability compared with individual clinical variables, highlighting its strength as a potential biomarker for recurrence. The dual upregulation of TOP2A and EZH2 was suggested as a biomarker for recurrence, particularly for patients not receiving neoadjuvant hormonal treatment, p = 0.001 (C-index = 0.84). While citrate was a statistically significant biomarker independent of hormonal treatment status, the current study indicated a potential of glutamine, glutamate and choline as biomarkers for recurrence among patients receiving neoadjuvant hormonal treatment, and glucose among patients not receiving neoadjuvant hormonal treatment.

CONCLUSION

Using an integrated approach, our study shows the potential of citrate and the dual upregulation of TOP2A and EZH2 as biomarkers for recurrence among radiotherapy patients.

New genetic determinants of VO2max-level identified by GWAS: The HUNT Study

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Central Norway Regional Health Authority

Norwegian Health Association

Introduction

Cardiovascular disease (CVD) is the leading cause of death worldwide. Several studies have shown that low cardiorespiratory fitness (CRF) is a major risk factor for CVD and is suggested to be a stronger predictor of CVD morbidity and mortality than established cardiovascular risk factors.

CRF quantified as maximal oxygen uptake (VO2max) has a strong genetic component, estimated to be ~50%. Unfortunately, current studies on genetic markers for CRF are limited by small sample sizes. In addition, there are few studies on directly measured VO2max, as most of the previous studies are based on estimated CRF. To overcome these limitations, we performed a large-scale systematic screening for genetic variants associated with VO2max aiming to provide awaited insight to this complex trait and discover possible links between VO2max and CVD.

Purpose

To identify and validate genetic factors associated with VO2max.

Methods

The genotypes of 70,000 participants from the Trøndelag Health study (HUNT) were imputed providing information on 25 million single-nucleotide polymorphisms (SNPs). We conducted a genome-wide association study (GWAS) including 4,525 participants with directly measured VO2max from the HUNT3 Fitness study. The GWAS was performed using BOLT-LMM, adjusted for age, gender, physical activity, principal components, and genotyping batch. In addition, we ran a GWAS with the same covariates except physical activity. Further, gender specific analyses were conducted. For validation, similar analyses were performed in the United Kingdom Biobank (UKBB). In the UKBB, CRF was assessed through a submaximal bicycle test. The analyses of UKBB included ~60,000 participants and over 90 million SNPs. Functional analyses of the GWAS results were examined by functional mapping and annotation (FUMA).

Results

Two GWAS-significant (p < 5×10-8) SNPs associated with VO2max were identified in the total population, two in the male population, and 24 in the female population in HUNT. Two of the 24 SNPs found in the female population were nominally significant in the UKBB. One of the validated SNPs in the female population is located inside PIK3R5, that is shown to be of importance in cardiac function and CVD. In addition, the functional analyses in the total- and male population revealed candidate SNPs in a gene previously found to be associated with endurance, PPP3CA.

Conclusions

We have identified 28 novel SNPs associated with VO2max in the HUNT cohort. Two of these SNPs were nominally validated in females in UKBB. One of the validated SNPs resides within a gene previously reported to be related to heart function and CVD. In addition, the functional analyses in the total- and male population revealed candidate SNPs in a gene previously found to be associated with endurance. Further functional analyses using bioinformatic approaches may provide more information on the physiological importance of these findings and their relation to CVD.

Identifying new genetic markers for maximal oxygen uptake

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Central Norway Regional Health AuthorityNorwegian Health Association

Introduction

Cardiovascular disease (CVD) is the leading cause of death worldwide. Several studies have shown that low cardiorespiratory fitness (CRF) is a major risk factor for CVD. Low CRF is suggested to be a stronger predictor of CVD morbidity and mortality than established cardiovascular risk factors like obesity, diabetes, and cholesterol.

Several studies suggest that CRF quantified as maximal oxygen uptake (VO2max) has a strong genetic component, estimated to be ~50%. Unfortunately, current studies on genetic markers for CRF are limited by small sample sizes. In addition, there are few studies on directly measured VO2max, as most of the previous studies are based on estimated CRF. Directly measured VO2max is considered as the gold standard for measuring CRF. Thus, a large-scale systematic screening for genetic variants associated with VO2max may provide awaited insight to this complex trait and discover possible links between VO2max and CVD.

Purpose

To identify and validate genetic factors associated with VO2max.

Methods

The genotypes of 70.000 participants from the Trøndelag Health study (HUNT) were imputed providing information on 25 million SNPs. We conducted a genome-wide association study (GWAS) including 4525 participants with directly measured VO2max from the HUNT3 Fitness study. The GWAS was performed using BOLT-LMM, adjusted for age, gender, physical activity, principal components, and genotyping batch. In addition, we ran a GWAS with the same covariates except physical activity. Further, gender specific analyses were conducted. For validation, similar analyses were performed in the United Kingdom Biobank (UKBB). In the UKBB, CRF was assessed through a submaximal bicycle test. The analyses of UKBB included ~60.000 participants and over 90 million SNPs.

Results

Two GWAS-significant (p < 5x10-8) SNPs associated with VO2max were identified in the total population in HUNT. Further, 24 GWAS-significant SNPs associated with VO2max in females, and two GWAS-significant SNPs associated with VO2max in males were discovered. Two of the 24 SNPs found in the female population were nominally significant in the UKBB. The validated SNPs are rs376927175, an intergenic SNP downstream of APBA1, and rs551942830 (proxy for rs190675254 with LD = 1.0), a 3 Prime UTR variant inside PIK3R5. PIK3R5 encodes the regulatory subunit of one class of PI3Ks, that is shown to be of importance in cardiac function and CVD. None of the SNPs found in the total population nor the male population were validated in UKBB.

Conclusions

We have identified 28 novel SNPs associated with VO2max in the HUNT cohort. Two of these SNPs were nominally validated in females in UKBB. One of the validated SNPs resides within a gene previously reported to be related to heart function and CVD. Further functional analyses using bioinformatic approaches may provide more information on the physiological importance of these findings and their relation to CVD.

Trace elements in whole blood in the general population in Trøndelag County, Norway: The HUNT3 Survey

BACKGROUND

Biomonitoring of a cohort within a large health survey can provide reliable information on trace element status. The main aims of this study were 1) to determine the concentrations of 28 trace elements in whole blood samples from the general population of the Nord-Trøndelag region, Norway, and 2) to investigate how trace element concentrations vary with geographical area, lifestyle, and socio-demographic factors.

METHODS

Whole blood samples were collected in the third survey of the Trøndelag Health Survey (HUNT3), a large population-based study in Norway. In total, 1011 whole blood samples from individuals aged 20-91 years were analyzed using high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS). We compared trace element concentrations (As, B, Be, Br, Ca, Cd, Cr, Cs, Cu, Ga, Au, In, Fe, Pb, Hg, Tl, Mg, Mn, Mo, Ni, Rb, Sc, Se, Ag, Sr, Sn, W and Zn) between three geographical areas (coastal, fjord/town, inland/mountain) using multivariable linear regression and assessed differences in trace element concentrations with socio-demographic and lifestyle factors using general linear models.

RESULTS

Trace element concentrations were generally comparable to levels reported in other recent studies and suggest low exposure to toxic trace elements in the region. We found geographical differences in concentrations of 19 trace elements. As, Br, Hg, and Se concentrations were higher on the coast compared to the fjord/town and inland/mountain areas, suggesting that the marine environment is an important source of exposure for these trace elements. In addition, socio-demographic and lifestyle characteristics, particularly age and sex, were associated with differences in trace element concentrations.

CONCLUSIONS

We report concentrations of 28 trace elements in the general population of a rural region with low exposure to pollution. Whole blood concentrations of trace elements varied with geographical area, the participants' lifestyle, and socio-demographic characteristics, highlighting the importance of considering these factors when evaluating trace element status in a population.

Genome-wide association study of cardiac troponin I in the general population

Circulating cardiac troponin proteins are associated with structural heart disease and predict incident cardiovascular disease in the general population. However, the genetic contribution to cardiac troponin I (cTnI) concentrations and its causal effect on cardiovascular phenotypes are unclear. We combine data from two large population-based studies, the Trøndelag Health Study and the Generation Scotland Scottish Family Health Study, and perform a genome-wide association study of high-sensitivity cTnI concentrations with 48 115 individuals. We further use two-sample Mendelian randomization to investigate the causal effects of circulating cTnI on acute myocardial infarction (AMI) and heart failure (HF). We identified 12 genetic loci (8 novel) associated with cTnI concentrations. Associated protein-altering variants highlighted putative functional genes: CAND2, HABP2, ANO5, APOH, FHOD3, TNFAIP2, KLKB1 and LMAN1. Phenome-wide association tests in 1688 phecodes and 83 continuous traits in UK Biobank showed associations between a genetic risk score for cTnI and cardiac arrhythmias, metabolic and anthropometric measures. Using two-sample Mendelian randomization, we confirmed the non-causal role of cTnI in AMI (5948 cases, 355 246 controls). We found indications for a causal role of cTnI in HF (47 309 cases and 930 014 controls), but this was not supported by secondary analyses using left ventricular mass as outcome (18 257 individuals). Our findings clarify the biology underlying the heritable contribution to circulating cTnI and support cTnI as a non-causal biomarker for AMI in the general population. Using genetically informed methods for causal inference helps inform the role and value of measuring cTnI in the general population.

Trace element status in patients with type 2 diabetes in Norway: The HUNT3 Survey

Several epidemiological studies have indicated that a number of trace elements may play a role in type 2 diabetes (T2D). We investigated the association between prevalent T2D and the concentrations of 25 trace elements in whole blood, and the relationships between T2D duration and blood levels of the trace elements that we found to be related to T2D prevalence. In this population based case-control study, 267 patients with self-reported T2D and 609 controls (frequency matched), were selected from the third Nord-Trøndelag Health Survey. Trace element blood levels were determined by high resolution inductively coupled plasma-mass spectrometry. Multivariable conditional logistic regression and multivariable linear regression were used to estimate associations. The prevalence of T2D was positively associated with boron, calcium and silver, and inversely associated with indium, lead and magnesium (P_trend<0.05). We found no statistical evidence for associations between blood levels of arsenic, bromine, cadmium, cesium, chromium, copper, gallium, gold, manganese, mercury, molybdenum, nickel, rubidium, selenium, strontium, tantalum, thallium, tin and zinc and T2D prevalence. After corrections for multiple testing, associations remained significant for calcium and lead (Q_trend<0.05), and borderline significant for magnesium, silver and boron. With increasing disease duration, higher calcium levels were observed (P<0.05). This study suggests an association between prevalent T2D and blood levels of boron, calcium, indium, lead, magnesium and silver.

Trace elements in early phase type 2 diabetes mellitus-A population-based study. The HUNT study in Norway

Differences in trace elements levels between individuals with type 2 diabetes and controls have been reported in several studies in various body fluids and tissues, but results have been inconsistent. In order to examine trace element levels in the early phase of type 2 diabetes, we investigated the association between whole blood levels of 26 trace elements and the prevalence of previously undiagnosed, screening-detected type 2 diabetes. The study was conducted as a case-control study nested within the third survey of the population-based Nord-Trøndelag Health Study (HUNT3 Survey). Among participants without previously known diabetes, 128 cases of type 2 diabetes were diagnosed in people with a high diabetes risk score (FINDRISC≥15), and frequency-matched for age and sex with 755 controls. Blood samples were analyzed by high resolution inductively coupled plasma mass spectrometry. Associations between trace element levels and the prevalence of previously undiagnosed type 2 diabetes were evaluated with multivariable conditional logistic regression controlling for age, sex, body mass index, waist-to-hip ratio, education, income, smoking and family history of diabetes. The prevalence of previously undiagnosed type 2 diabetes increased across tertiles/quartiles for cadmium, chromium, iron, nickel, silver and zinc, and decreased with increasing quartiles of bromine (P_trend<0.05). After corrections for multiple testing, associations for chromium remained significant (Q_trend<0.05), while associations for iron and silver were borderline significant. No associations were found for arsenic, boron, calcium, cesium, copper, gallium, gold, indium, lead, magnesium, manganese, mercury, molybdenum, rubidium, selenium, strontium, tantalum, thallium and tin. Our results suggest a possible role of bromine, cadmium, chromium, iron, nickel, silver and zinc in the development of type 2 diabetes.

Metabolic markers in blood can separate prostate cancer from benign prostatic hyperplasia

Background:

An individualised risk-stratified screening for prostate cancer (PCa) would select the patients who will benefit from further investigations as well as therapy. Current detection methods suffer from low sensitivity and specificity, especially for separating PCa from benign prostatic conditions. We have investigated the use of metabolomics analyses of blood samples for separating PCa patients and controls with benign prostatic hyperplasia (BPH).

Methods:

Blood plasma and serum samples from 29 PCa patient and 21 controls with BPH were analysed by metabolomics analysis using magnetic resonance spectroscopy, mass spectrometry and gas chromatography. Differences in blood metabolic patterns were examined by multivariate and univariate statistics.

Results:

By combining results from different methodological platforms, PCa patients and controls were separated with a sensitivity and specificity of 81.5% and 75.2%, respectively.

Conclusions:

The combined analysis of serum and plasma samples by different metabolomics measurement techniques gave successful discrimination of PCa and controls, and provided metabolic markers and insight into the processes characteristic of PCa. Our results suggest changes in fatty acid (acylcarnitines), choline (glycerophospholipids) and amino acid metabolism (arginine) as markers for PCa compared with BPH.

A dynamic 3D biomechanical evaluation of the load on the low back during different patient-handling tasks

The objective of this study was to investigate the low-back loading during common patient-handling tasks. Ten female health care workers without formal training in patient handling performed nine patient-handling tasks including turning, lifting and repositioning a male stroke patient. The low-back loading was quantified by net moment, compression, and shear forces at the L4/L5 joint, measured muscle activity (EMG) in erector spinae muscles and rate of perceived exertion (RPE; Borg scale). The experiments were videotaped with a 50Hz video system using five cameras, and the ground and bedside reaction forces of the health care worker were recorded by means of force platforms and force transducers on the bed. The biomechanical load was calculated using a dynamic 3D seven-segment model of the lower part of the body, and the forces at the L4/L5 joint were estimated by a 14 muscles cross-sectional model of the low back (optimisation procedure). Compression force and torque showed high task dependency whereas the EMG data and the RPE values were more dependent on the subject. The peak compression during two tasks involving lifting the patient (4132/4433N) was significantly higher than all other tasks. Four tasks involving repositioning the patient in the bed (3179/3091/2932/3094N) did not differ, but showed higher peak compression than two tasks turning the patient in the bed (1618/2197N). Thus, in this study the patient-handling tasks could be classified into three groups-characterised by lifting, repositioning or turning-with different levels of peak net torque and compression at the L4/L5 joint.

Aerobic power and muscle strength among young and elderly workers with and without physically demanding work tasks

The aim of the study was to investigate the effect of waste collection on the physical capacity of the workers. A total of 19 young and 28 elderly male waste collectors and two age-matched control groups participated. The aerobic power was estimated. The maximal isometric muscle strength was measured for back extension and flexion, shoulder elevation and abduction, and handgrip. The aerobic power was lower among the elderly workers compared with the young workers of both groups. No differences were found between waste collectors and control groups. A general tendency to larger muscle strength was found for both young and elderly waste collectors compared with the control groups. Waste collectors generally have a higher physical capacity than the control groups which is an indication of an early selection of the young waste collectors. With respect to the elderly waste collectors, the job seems to have a training effect especially for the shoulder muscles. No training effect is found for the aerobic power, and a discrepancy between work demand and individual aerobic capacity may occur among elderly workers resulting in a negative health effect unless the work task is evaluated according to age dependent criteria.

A possible explanation of wet and dry nights in enuretic children

OBJECTIVE

To clarify the relationship between nocturnal urine production and the occurrence of both wet and dry nights in patients with nocturnal enuresis and to estimate the effect on nocturnal urine production of treatment with the antidiuretic hormone desmopressin in a group of enuretics with none or only a partial reduction in the number of wet nights in response to desmopressin treatment.

PATIENTS AND METHODS

The nocturnal urine production of 60 children with monosymptomatic nocturnal enuresis was measured for 14 nights with no treatment (baseline) and for 14 nights with desmopressin treatment. Sixteen children having both wet and dry nights in the two periods were chosen for the subsequent analysis.

RESULTS

There was significantly less nocturnal urine production during desmopressin treatment (202 mL/night) than during the baseline period (279 mL/night; P < 0.001) and a corresponding decrease in the number of wet nights, from 10 during baseline to five during desmopressin treatment. When expressed as mL/kg body weight per hour, the urine production during baseline was 0.89 on wet and 0.625 on dry nights (P < 0.001), and during desmopressin treatment was 0.716 and 0.535, respectively (P < 0.01).

CONCLUSION

In this group of enuretics there was a clear reduction in the number of wet nights and in nocturnal urine production during desmopressin treatment, even though none became totally dry on desmopressin. There was a markedly higher nocturnal urine production on wet nights during both the baseline period and during desmopressin treatment. The higher urine production on wet nights could explain the enuretic episode, with urine production exceeding bladder capacity.

Alarm treatment: influence on functional bladder capacity

Home recordings were used to study the effect of alarm treatment, over a period of 6 weeks, in children with monosymptomatic nocturnal enuresis. Vasopressin day/night ratios were shown to be a good indicator of alarm treatment success. Serial measurement of plasma vasopressin levels is, however, unsuitable for use in the clinic, as extensive analyses would have to be performed to obtain the necessary results. Use of an alarm increased nocturnal bladder capacity, but had no effect on daytime bladder capacity, sleep patterns, vasopressin secretion, nocturnal urine output or pelvic floor activity. In addition, the results of the study suggest that an alarm treatment period of 2 months would lead to more successful results than the 6 weeks used in the study.

Long-term home studies of water balance in patients with nocturnal enuresis

A 2-week, home-based study was conducted on 75 children with nocturnal enuresis to monitor the frequency of enuretic episodes and the volume of nocturnal urine production. The objectives of the study were to correlate nocturnal urine production to the occurrence of nocturnal enuresis and response to desmopressin (Minirin, DDAVP) treatment. Furthermore, patient compliance was evaluated. Enuresis episodes and nocturnal urine production was recorded every night during two base-line weeks without treatment and during 2 weeks with 20-40 micrograms desmopressin at bedtime. During both periods fluid intake and micturition volumes were recorded for 2 days. Desmopressin response was defined as > 50% reduction in wet nights during treatment. It was found that patient compliance was acceptable in most patients. Regarding urine output it was found that base-line nocturnal urine production was significantly higher during nights when enuresis occurred than during "dry" nights and significantly higher in desmopressin responders compared with desmopressin non-responders. During treatment with desmopressin, nocturnal urine production in desmopressin responders decreased to levels similar to those of non-responders. The results confirm inpatient circadian studies of urine output and emphasise the importance of nocturnal polyuria in patients with monosymptomatic enuresis. The response to desmopressin was found to correlate with the occurrence of nocturnal polyuria. Home studies were considered to be a useful tool in the characterisation of patients with nocturnal enuresis.