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.
Electronic supplementary material
The online version of this article (doi:10.1007/s00439-011-0981-1) contains supplementary material, which is available to authorized users.
Prostate cancer (PrCa) is one of the most common diseases to affect men worldwide and among the leading causes of cancer-related death. The purpose of this study was to use second-generation sequencing technology to assess the frequency of deleterious mutations in 22 tumour suppressor genes in familial PrCa and estimate the relative risk of PrCa if these genes are mutated.
Germline DNA samples from 191 men with 3 or more cases of PrCa in their family were sequenced for 22 tumour suppressor genes using Agilent target enrichment and Illumina technology. Analysis for genetic variation was carried out by using a pipeline consisting of BWA, Genome Analysis Toolkit (GATK) and ANNOVAR. Clinical features were correlated with mutation status using standard statistical tests. Modified segregation analysis was used to determine the relative risk of PrCa conferred by the putative loss-of-function (LoF) mutations identified.
We discovered 14 putative LoF mutations in 191 samples (7.3%) and these mutations were more frequently associated with nodal involvement, metastasis or T4 tumour stage (P=0.00164). Segregation analysis of probands with European ancestry estimated that LoF mutations in any of the studied genes confer a relative risk of PrCa of 1.94 (95% CI: 1.56–2.42).
These findings show that LoF mutations in DNA repair pathway genes predispose to familial PrCa and advanced disease and therefore warrants further investigation. The clinical utility of these findings will become increasingly important as targeted screening and therapies become more widespread.
familial prostate cancer; DNA repair gene mutations; next-generation sequencing; relative risk
Prostate cancer (PrCa) is the most common non-skin cancer diagnosed among males in developed countries and the second leading cause of cancer mortality, yet little is known regarding its etiology and factors that influence clinical outcome. Genome-wide association studies (GWAS) of PrCa have identified at least 30 distinct loci associated with small differences in risk. We conducted a GWAS in 2782 advanced PrCa cases (Gleason grade ≥ 8 or tumor stage C/D) and 4458 controls with 571 243 single nucleotide polymorphisms (SNPs). Based on in silico replication of 4679 SNPs (Stage 1, P < 0.02) in two published GWAS with 7358 PrCa cases and 6732 controls, we identified a new susceptibility locus associated with overall PrCa risk at 2q37.3 (rs2292884, P= 4.3 × 10−8). We also confirmed a locus suggested by an earlier GWAS at 12q13 (rs902774, P= 8.6 × 10−9). The estimated per-allele odds ratios for these loci (1.14 for rs2292884 and 1.17 for rs902774) did not differ between advanced and non-advanced PrCa (case-only test for heterogeneity P= 0.72 and P= 0.61, respectively). Further studies will be needed to assess whether these or other loci are differentially associated with PrCa subtypes.
Only a minority of the genetic component of prostate cancer (PrCa) risk has been explained. Some observed associations of single nucleotide polymorphisms (SNPs) with PrCa might arise from associations of these SNPs with circulating prostate specific antigen (PSA) because PSA values are used to select controls.
We undertook a genome-wide association study (GWAS) of screen detected PrCa (ProtecT 1146 cases and 1804 controls); meta-analysed the results with those from the previously published UK Genetic Prostate Cancer Study (1854 cases and 1437 controls); investigated associations of SNPs with PrCa using either ‘low’ (PSA <0.5ng/ml) or ‘high’ (PSA ≥3ng/ml, biopsy negative) PSA controls; and investigated associations of SNPs with PSA.
The ProtecT GWAS confirmed previously reported associations of PrCa at 3 loci: 10q11.23, 17q24.3 and 19q13.33. The meta-analysis confirmed associations of PrCa with SNPs near 4 previously identified loci (8q24.21,10q11.23, 17q24.3 and 19q13.33). When comparing PrCa cases with low PSA controls, alleles at genetic markers rs1512268, rs445114, rs10788160, rs11199874, rs17632542, rs266849 and rs2735839 were associated with an increased risk of PrCa, but the effect-estimates were attenuated to the null when using high PSA controls (p for heterogeneity in effect-estimates<0.04). We found a novel inverse association of rs9311171-T with circulating PSA.
Differences in effect estimates for PrCa observed when comparing low vs. high PSA controls, may be explained by associations of these SNPs with PSA.
These findings highlight the need for inferences from genetic studies of PrCa risk to carefully consider the influence of control selection criteria.
Prostate Specific Antigen; research design; prostate cancer; case-control studies; genome wide association studies
Although prostate cancer (PrCa) is one of the most common cancers in men in Western countries, little is known about the inherited factors that influence PrCa risk. On the basis of the fact that BRIP1/FANCJ interacts with BRCA1 and functions as a regulator of DNA double-strand break repair pathways, and that germline mutations within the BRIP1/FANCJ gene predispose to breast cancer, we chose this gene as a candidate for mutation screening in familial and young-onset PrCa cases. We identified a truncating mutation, R798X, in the BRIP1/FANCJ gene in 4 out of 2714 UK PrCa cases enriched for familial (2 out of 641; 0.3%) and young-onset cases (2 out of 2073; 0.1%). On screening 2045 controls from the UK population, we found one R798X sequence alteration (0.05%; odds ratio 2.4 (95% CI 0.25–23.4)). In addition, using our data from a genome-wide association study, we analysed 25 SNPs in the genomic region of the BRIP1/FANCJ gene. Two SNPs showed evidence of association with familial and young-onset PrCa (rs6504074; Ptrend=0.04 and rs8076727; Ptrend=0.01). These results suggest that truncating mutations in BRIP1/FANCJ might confer an increased risk of PrCa and common SNPs might also contribute to the alteration of risk, but larger case–control series will be required to confirm or refute this association.
prostate cancer predisposition; FANCJ/BRIP1; deleterious mutation; SNPs
Genome-wide association studies (GWAS) have identified multiple genetic variants associated with susceptibility to prostate cancer (PrCa). In the two-stage Cancer Genetic Markers of Susceptibility (CGEMS) prostate cancer scan, a single-nucleotide polymorphism (SNP) rs10486567 located within intron 2 of JAZF1 gene on chromosome 7p15.2 showed a promising association with PrCa overall (p = 2.14×10−6) with a suggestion of stronger association with aggressive disease (p = 1.2×10−7).
In the third stage of GWAS, we genotyped 106 JAZF1 SNPs in 10,286 PrCa cases and 9,135 controls of European ancestry.
The strongest association was observed with the initial marker, rs10486567, which now achieves genome-wide significance (p = 7.79×10−11, ORHET 1.19; 95%CI = 1.12 – 1.27 and ORHOM 1.37; 95%CI = 1.20 – 1.56). We did not confirm a previous suggestion of a stronger association of rs10486567 with aggressive disease (p = 1.60×10−4 for aggressive cancer, n=4,597; p = 3.25×10−8 for non-aggressive cancer, n=4,514). Based on a multi-locus model with adjustment for rs10486567, no additional independent signals were observed at chromosome 7p15.2. There was no association between PrCa risk and SNPs in JAZF1 previously associated with height (rs849140, p = 0.587), body stature (rs849141, tagged by rs849136, p = 0.171), risk of type 2 diabetes and systemic lupus erythematosus (rs864745, tagged by rs849142, p = 0.657).
rs10486567 remains the most significant marker for PrCa risk within JAZF1 in individuals of European ancestry.
Future studies should identify all variants in high LD with rs10486567 and evaluate their functional significance for PrCa.
There is a known inverse association between type 2 diabetes (T2D) and prostate cancer (PrCa) that is poorly understood. Genetic studies of the T2D-PrCa association may provide insight into the underlying mechanisms of this association. We evaluated associations in the Atherosclerosis Risk in Communities study between PrCa and nine T2D single nucleotide polymorphisms (SNPs) from genome-wide association (GWA) studies of T2D (in CDKAL1, CDKN2A/B, FTO, HHEX, IGF2BP2, KCNJ11, PPARG, SLC30A8, and TCF7L2) and four T2D SNPs from pre-GWA studies (in ADRB2, CAPN10, SLC2A2, and UCP2). From 1987–2000, there were 397 incident PrCa cases among 6,642 men aged 45–64 years at baseline. We used race-adjusted Cox proportional hazards models to estimate associations between PrCa and increasing number of T2D risk-raising alleles. PrCa was positively associated with the CAPN10 rs3792267 G allele (hazard ratio [HR]=1.20; 95% confidence interval [CI]=1.00, 1.44) and inversely associated with the SLC2A2 rs5400 Thr110 allele (HR=0.85; 95% CI=0.72, 1.00), the UCP2 rs660339 Val55 allele (HR=0.84; 95% CI=0.73, 0.97) and the IGF2BP2 rs4402960 T allele (HR=0.79; 95% CI=0.61, 1.02; blacks only). The TCF7L2 rs7903146 T allele was inversely associated with PrCa using a dominant genetic model (HR=0.79; 95% CI=0.65, 0.97). Further knowledge of T2D gene-PrCa mechanisms may improve understanding of PrCa etiology.
Diabetes Mellitus; Type 2; Genetics; Risk; Polymorphism; Single Nucleotide; Prostatic Neoplasms
Men of African descent have the highest incidence and mortality rates of prostate cancer (PrCa) worldwide. Notably, PrCa is increasing in Africa with Nigerian men being mostly affected. Thus, it is important to understand risk factors for PrCa in Nigeria and build capacity for cancer research. The goals of this study were to determine the feasibility of conducting an epidemiological study of PrCa and to obtain preliminary data on risk factors for PrCa in Nigeria.
A case–control study (50 cases/50 controls) was conducted at the University College Hospital (UCH) in Ibadan, Nigeria, between October 2011 and December 2012. Men aged 40 to 80 years were approached for the study and asked to provide informed consent and complete the research protocol. Logistic regression models were used to examine associations between demographic, social and lifestyle characteristics and risk of PrCa.
The participation rate among cases and controls was 98% and 93%, respectively. All participants completed a questionnaire and 99% (50 cases/49 controls) provided blood samples. Cases had a median serum diagnostic PSA of 73 ng/ml, and 38% had a Gleason score 8–10 tumor. Family history of PrCa was associated with a 4.9-fold increased risk of PrCa (95% CI 1.0 - 24.8). There were statistically significant inverse associations between PrCa and height, weight and waist circumference, but there was no association with body mass index (kg/m2). There were no associations between other socio-demographic and lifestyle characteristics and PrCa risk.
This feasibility study demonstrated the ability to ascertain and recruit participants at UCH and collect epidemiological, clinical and biospecimen data. Our results highlighted the advanced clinical characteristics of PrCa in Nigerian men, and that family history of PrCa and some anthropometric factors were associated with PrCa risk in this population. However, larger studies are needed to better understand the epidemiological risk factors of PrCa in Nigeria.
Prostate cancer; Epidemiologic study; Case–control study; Feasibility study; Nigeria; African men
Heritable factors are evidently involved in prostate cancer (PrCa) carcinogenesis, but currently, genetic markers are not routinely used in screening or diagnostics of the disease. More precise information is needed for making treatment decisions to distinguish aggressive cases from indolent disease, for which heritable factors could be a useful tool. The genetic makeup of PrCa has only recently begun to be unravelled through large-scale genome-wide association studies (GWAS). The thus far identified Single Nucleotide Polymorphisms (SNPs) explain, however, only a fraction of familial clustering. Moreover, the known risk SNPs are not associated with the clinical outcome of the disease, such as aggressive or metastasised disease, and therefore cannot be used to predict the prognosis. Annotating the SNPs with deep clinical data together with miRNA expression profiles can improve the understanding of the underlying mechanisms of different phenotypes of prostate cancer.
In this study microRNA (miRNA) profiles were studied as potential biomarkers to predict the disease outcome. The study subjects were from Finnish high risk prostate cancer families. To identify potential biomarkers we combined a novel non-parametrical test with an importance measure provided from a Random Forest classifier. This combination delivered a set of nine miRNAs that was able to separate cases from controls. The detected miRNA expression profiles could predict the development of the disease years before the actual PrCa diagnosis or detect the existence of other cancers in the studied individuals. Furthermore, using an expression Quantitative Trait Loci (eQTL) analysis, regulatory SNPs for miRNA miR-483-3p that were also directly associated with PrCa were found.
Based on our findings, we suggest that blood-based miRNA expression profiling can be used in the diagnosis and maybe even prognosis of the disease. In the future, miRNA profiling could possibly be used in targeted screening, together with Prostate Specific Antigene (PSA) testing, to identify men with an elevated PrCa risk.
There is a high and rising prevalence of prostate cancer (PRCA) within the male population of the United Kingdom. Although the relative risk of PRCA is higher in male BRCA2 and BRCA1 mutation carriers, the histological characteristics of this malignancy in these groups have not been clearly defined. We present the histopathological findings in the first UK series of BRCA1 and BRCA2 mutation carriers with PRCA. The archived histopathological tissue sections of 20 BRCA1/2 mutation carriers with PRCA were collected from histopathology laboratories in England, Ireland and Scotland. The cases were matched to a control group by age, stage and serum PSA level of PRCA cases diagnosed in the general population. Following histopathological evaluation and re-grading according to current conventional criteria, Gleason scores of PRCA developed by BRCA1/2 mutation carriers were identified to be significantly higher (Gleason scores 8, 9 or 10, P=0.012) than those in the control group. Since BRCA1/2 mutation carrier status is associated with more aggressive disease, it is a prognostic factor for PRCA outcome. Targeting screening to this population may detect disease at an earlier clinical stage which may therefore be beneficial.
prostate cancer; BRCA1 and BRCA2; prostate pathology
A recent genome-wide association (GWA) study suggested seven new loci as associated with prostate cancer (PRCA) susceptibility. The strongest associated SNP in each region was identified (rs2660753, rs9364554, rs6465657, rs10993994, rs7931342, rs2735839, rs5945619). We studied these seven SNPs in a replication study consisting of 169 familial PRCA cases selected from Utah high-risk PRCA pedigrees and 805 controls. We performed subset analyses for aggressive and early onset PRCA. At a nominal significance level, two SNPs were found to be associated with PRCA: rs10993994 on chromosome 10q11 (odds ratio (OR) =1.42 [95% confidence interval (CI), 1.05–1.90], p=0.022); and rs5945619 on chromosome Xp11 (OR=1.54 [95% CI, 1.03–2.31], p=0.035). Restricting analysis to familial PRCA cases with aggressive disease yielded very similar risk estimates at both SNPs. However, subset analysis for familial, early onset disease indicated highly significant association evidence and substantially higher risk estimates for rs10993994 (OR=2.20 [95% CI, 1.48–3.27], p<0.0001). This result suggests that the higher risk estimates from the stage 1 cohort in the original study for rs10993994 may have been due to the early-onset and familial nature of the PRCA cases in that cohort. In conclusion, in a small case-control study of PRCA cases from Utah high-risk pedigrees, we have significantly replicated association of PRCA with rs10993994 (10q11) upon study-wide correction for multiple comparisons. We also nominally replicated the association of PRCA with rs5945619 (Xp11). In particular, it appears that the susceptibility locus at 10q11 maybe involved in familial, early onset disease.
Prostate Cancer; Genetic Risk
Understanding the impact of multiple genetic variants and their interactions on the disease penetrance of familial multiple prostate cancer is very relevant to the overall understanding of carcinogenesis. We assessed the joint effect of two loci on rs4242382 at 8q24 and rs10486567 at 7p15.2 to this end. We analyzed the data from a Finnish family-based genetic study, which was composed of 947 men including 228 cases in 75 families, to evaluate the respective effects of the two loci on the disease penetrance; in particular, the occurrence and number of prostate cancer cases within a family were utilized to evaluate the interactions between the two loci under the additive and multiplicative Poisson regression models. The risk alleles A at rs4242382 (OR = 1.14, 95% CI 1.08–1.19, P<0.0001) and a risk allele A at rs10486567 (OR = 1.06, 96%CI 1.01–1.11, P = 0.0208) were found to be associated with an increased risk of familial PrCa, especially with four or more cases within a family. A multiplicative model fitted the joint effect better than an additive model (likelihood ratio test X2 = 13.89, P<0.0001). The influence of the risk allele A at rs10486567 was higher in the presence of the risk allele A at rs4242382 (OR = 1.09 (1.01–1.18) vs. 1.01 (0.95–1.07)). Similar findings were observed in non-aggressive PrCa, but not in aggressive PrCa. We demonstrated that two loci (rs4242382 and rs10486567) are highly associated with familial multiple PrCa, and the gene-gene interaction or statistical epistasis was consistent with the Fisher's multiplicative model. These loci's association and epistasis were observed for non-aggressive but not for aggressive tumors. The proposed statistical model can be further developed to accommodate multi-loci interactions to provide further insights into epistasis.
Associations between single nucleotide polymorphisms (SNPs) at 5p15 and multiple cancer types have been reported. We have previously shown evidence for a strong association between prostate cancer (PrCa) risk and rs2242652 at 5p15, intronic in the telomerase reverse transcriptase (TERT) gene that encodes TERT. To comprehensively evaluate the association between genetic variation across this region and PrCa, we performed a fine-mapping analysis by genotyping 134 SNPs using a custom Illumina iSelect array or Sequenom MassArray iPlex, followed by imputation of 1094 SNPs in 22 301 PrCa cases and 22 320 controls in The PRACTICAL consortium. Multiple stepwise logistic regression analysis identified four signals in the promoter or intronic regions of TERT that independently associated with PrCa risk. Gene expression analysis of normal prostate tissue showed evidence that SNPs within one of these regions also associated with TERT expression, providing a potential mechanism for predisposition to disease.
Men with germline BRCA1/2 mutations have a higher risk of developing prostate cancer than non-carriers. IMPACT is an international consortium of 62 centres in 20 countries evaluating the use of targeted PrCa screening in men with BRCA1/2 mutations.
To report the first year’s screening results for all men at enrolment in the study.
Outcome Measurements and Statistical Analysis
PSA levels, PrCa incidence, and tumour characteristics were evaluated. Fisher’s exact test was used to compare the number of PrCa cases between groups and differences between disease types.
Design, setting and participants
We recruited men aged 40–69 years with germline BRCA1/2 mutations and a control group of men who have tested negative for a pathogenic BRCA1 or BRCA2 mutation known to be present in their family. All men underwent PSA testing at enrolment and those with a PSA >3ng/ml offered prostate biopsy.
Results and limitations
We recruited 2,481 men (791 BRCA1 carriers, 531 BRCA1 controls; 731 BRCA2 carriers, 428 BRCA2 controls). 199 (8%) presented with a PSA >3ng/ml, 162 biopsies were performed and 59 PrCas diagnosed (18 BRCA1 carriers, 10 BRCA1 controls; 24 BRCA2 carriers, 7 BRCA2 controls); 66% of tumours were classified as intermediate or high-risk disease. The positive-predictive-value for biopsy using a PSA threshold of 3.0ng/ml in BRCA2 mutation carriers was 48%, double that reported in population screening studies. A significant difference in detecting intermediate or high-risk disease was observed in BRCA2 carriers. 95% of men were Caucasian thus the results cannot be generalised to all ethnic groups.
The IMPACT screening network will be useful for targeted PrCa screening studies in men with germline genetic risk variants as they are discovered. These preliminary results support the use of targeted PSA screening based on BRCA genotype and show that this yields a high proportion of aggressive disease.
In this report we demonstrate that germline genetic markers can be used to identify men at higher risk of PrCa. Targeting screening at these men resulted in the identification of tumours that were more likely to require treatment.
BRCA1; BRCA2; Prostate cancer; Prostate-Specific-Antigen; Targeted screening
Genome-wide association studies (GWAS) have identified multiple SNPs associated with prostate cancer (PrCa). Population isolates may have different sets of risk alleles for PrCa constituting unique population and individual risk profiles.
To test this hypothesis, associations between 31 GWAS SNPs of PrCa were examined among 979 PrCa cases and 1,251 controls of Ashkenazic descent using logistic regression. We also investigated risks by age at diagnosis, pathological features of PrCa, and family history of cancer. Moreover, we examined associations between cumulative number of risk alleles and PrCa and assessed the utility of risk alleles in PrCa risk prediction by comparing the area under the curve (AUC) for different logistic models.
Of the 31 genotyped SNPs, 8 were associated with PrCa at p≤0.002 (corrected p-value threshold) with odds ratios (ORs) ranging from 1.22 to 1.42 per risk allele. Four SNPs were associated with aggressive PrCa, while three other SNPs showed potential interactions for PrCa by family history of PrCa (rs8102476; 19q13), lung cancer (rs17021918; 4q22), and breast cancer (rs10896449; 11q13). Men in the highest vs. lowest quartile of cumulative number of risk alleles had ORs of 3.70 (95% CI 2.76–4.97); 3.76 (95% CI 2.57–5.50), and 5.20 (95% CI 2.94–9.19) for overall PrCa, aggressive cancer and younger age at diagnosis, respectively. The addition of cumulative risk alleles to the model containing age at diagnosis and family history of PrCa yielded a slightly higher AUC (0.69 vs. 0.64).
These data define a set of risk alleles associated with PrCa in men of Ashkenazic descent and indicate possible genetic differences for PrCa between populations of European and Ashkenazic ancestry. Use of genetic markers might provide an opportunity to identify men at highest risk for younger age of onset PrCa; however, their clinical utility in identifying men at highest risk for aggressive cancer remains limited.
The HOXB13 gene has been implicated in prostate cancer (PrCa) susceptibility. We performed a high resolution fine-mapping analysis to comprehensively evaluate the association between common genetic variation across the HOXB genetic locus at 17q21 and PrCa risk. This involved genotyping 700 SNPs using a custom Illumina iSelect array (iCOGS) followed by imputation of 3195 SNPs in 20,440 PrCa cases and 21,469 controls in The PRACTICAL consortium. We identified a cluster of highly correlated common variants situated within or closely upstream of HOXB13 that were significantly associated with PrCa risk, described by rs117576373 (OR 1.30, P = 2.62×10−14). Additional genotyping, conditional regression and haplotype analyses indicated that the newly identified common variants tag a rare, partially correlated coding variant in the HOXB13 gene (G84E, rs138213197), which has been identified recently as a moderate penetrance PrCa susceptibility allele. The potential for GWAS associations detected through common SNPs to be driven by rare causal variants with higher relative risks has long been proposed; however, to our knowledge this is the first experimental evidence for this phenomenon of synthetic association contributing to cancer susceptibility.
Genome-wide association studies (GWAS) have identified numerous low penetrance disease susceptibility variants, yet few causal alleles have been unambiguously identified. The underlying causal variants are expected to be predominantly common; however synthetic associations with rare, higher penetrance variants have been hypothesised though not yet observed. Here, we report detection of a novel common, low penetrance prostate cancer association at the HOXB locus at ch17q and show that this signal can actually be attributed to a previously identified rare, moderate penetrance coding variant (G84E) in HOXB13. This study therefore provides the first experimental evidence for the existence of synthetic associations in cancer and shows that where GWAS signals arise through this phenomenon, risk predictions derived using the tag SNP would substantially underestimate the relative risk conferred and overestimate the number of carriers of the causal variant. Synthetic associations at GWAS signals could therefore account for a proportion of the missing heritability of complex diseases.
A family history of prostate cancer (PrCa) is a strong risk factor for the disease, indicating that inherited factors are important in this disease. We previously estimated that about 2% of PrCa cases diagnosed ⩽55 years harbour a BRCA2 mutation and PrCa among BRCA2 carriers has been shown to be more aggressive, with poorer survival.
To further evaluate the role of BRCA2 in PrCa predisposition, we screened 1864 men with PrCa aged between 36 and 88 years. We analysed the BRCA2 gene using a novel high-throughput multiplex fluorescence heteroduplex detection system developed for the ABI3130xl genetic analyzer.
We identified 19 protein-truncating mutations, 3 in-frame deletions and 69 missense variants of uncertain significance (UV) in our sample set. All the carriers of truncating mutations developed PrCa at ⩽65 years, with a prevalence of BRCA2 mutation of 1.20% for cases in this age group.
Based on the estimated frequency of BRCA2 mutations in the United Kingdom we estimate that germline mutations in the BRCA2 gene confer an ∼8.6-fold increased risk of PrCa by age 65, corresponding to an absolute risk of ∼15% by age 65. These results suggest that routine testing of early onset PrCa cases for germline BRCA2 mutations will further help to refine the prevalence and risk associated with BRCA2 mutations and may be useful for guiding management options.
prostate cancer; BRCA2 gene; mutation screening; cancer risk
PALB2 1592delT mutation is associated with increased breast cancer and suggestive prostate cancer (PRCA) risk in Finland. In this study we wanted to assess if any other PALB2 variants associate to increased PRCA risk and clinically describe patients with formerly found PALB2 1592delT mutation.
Finnish families with two or more PRCA cases (n = 178) and unselected cases (n = 285) with complete clinical data were initially screened for variants in the coding region and splice sites of PALB2. Potentially interesting variants were verified in additional set of unselected cases (n = 463).
From our clinically defined sample set we identified total of six variants in PALB2. No novel variants among Finnish PRCA cases were found. Clinical characteristics of the variant carriers, including the previously described family carrying PALB2 1592delT, revealed a trend towards aggressive disease, which also applied to a few non-familial cases. Hypersensitivity to mitomycin C (MMC) of lymphoblasts from individuals from the family with 1592delT revealed haploinsufficiency among carriers with altered genotype.
Though any of the detected PALB2 variants do not associate to PRCA in population level in Finland it cannot be ruled out that some of these variants contribute to cancer susceptibility at individual level.
Background: The manganese superoxide dismutase (MnSOD) gene encodes an antioxidant enzyme (SOD2) that may protect cells from oxidative damage. The MnSOD allele with Val as amino acid 16 encodes a protein that has 30–40% lower activity compared with the MnSOD Ala variant, hence possibly increasing susceptibility to oxidative stress. On the other hand, some epidemiologic studies suggest that the Ala allele is associated with a higher risk of cancer, including prostate cancer. Methods: We conducted a nested case–control study in the Health Professionals Follow-up Study with 612 incident prostate cancer cases and 612 matched controls to investigate the role of the MnSOD gene Ala16Val polymorphism and its joint association with plasma carotenoid concentrations in relation to risk of total prostate cancer and aggressive prostate cancer (advanced stage or Gleason sum ≥7). Results: The allele frequencies in the controls were 49.8% for Ala and 50.2% for Val. No association was found between the MnSOD genotype and risk of total and aggressive prostate cancer. Furthermore, no statistically significant interaction was observed between the MnSOD genotype and any of the plasma carotenoids in relation to risk of total and aggressive prostate cancer. In analyses in which we combined data from plasma and dietary carotenoids and created a quintile score to reflect long-term carotenoid status, a 3-fold [95% confidence interval: 1.37–7.02] increased risk of aggressive prostate cancer was observed among men with the Ala/Ala genotype in the presence of low long-term lycopene status (P-value, test for interaction = 0.02) as compared with men with the Ala/Val+Val/Val genotypes with low long-term lycopene status. Conclusion: In this cohort of mainly white men, the MnSOD gene Ala16Val polymorphism was not associated with total or aggressive prostate cancer risk. However, men with the MnSOD Ala/Ala genotype who had low long-term lycopene status had a higher risk of aggressive prostate cancer compared with individuals with the other genotypes. These results are consistent with findings from earlier studies that reported when antioxidant status is low, the MnSOD Ala/Ala genotype may be associated with an increased risk of aggressive prostate cancer.
Prostate cancer (PrCa) has a high incidence in Western countries and at present, there is no cure for hormone refractory prostate cancer. Transgenic mouse models have proven useful for understanding mechanisms of prostate carcinogenesis. The characterization of genetically modified mouse PrCa models using high-throughput genomic analyses provides important information to guide appropriate experiment applications for such model.
We have analyzed the transcriptome of the hormone refractory and highly metastatic Fetal Globin-SV40/T-antigen (Gγ-globin-Tag) transgenic mouse model for PrCa compared to normal mouse prostate tissue. Gene expression patterns found in Gγ-globin-Tag mouse prostate tumors were compared with publicly available human localized and metastatic prostate tumors (GEO accession # GSE3325) through hierarchical cluster analysis, Pearson’s rank correlation coefficient, and Self Organizing Feature Maps (SOM) analyses.
Gγ-globin-Tag tumors clustered closely with human metastatic tumors and gene expression patterns had a significant correlation (P < 0.01), unlike human localized primary tumors (P > 0.6). Bioinformatic analyses identified deregulated genetic pathways and networks in Gγ-globin-Tag tumors, which displayed similarities to alterations in human PrCa. Changes in the expression of genes involved in DNA replication and repair (Rb1, p53, Myc, PCNA, DNMT3A) and growth factor signaling pathways (TGFβ2, ERK1/2, NRas, and Notch1) are deregulated in the Gγ-globin-Tag tumors, suggesting their key role in the oncogenic process. Identification of an enrichment of putative binding sites for transcription factors revealed eight transcription factors that may be important in Gγ-globin-Tag carcinogenesis, including SP1, NF-Y, CREB, Elk1, and E2F. Novel genes related to microtubule regulation were also identified in Gγ-globin-Tag tumors as potentially important candidate targets for PrCa. Overexpression of stathmin-1, whose expression was increased in human metastatic prostate tumors, was validated in Gγ-globin-Tag tumors by immunohistochemistry. This protein belongs to the SV40/T-antigen cancer signature identified in previous studies in prostate, breast, and lung cancer mouse models.
Our results show that the Gγ-globin-Tag model for hormone refractory PrCa shares important features with aggressive, metastatic human PrCa. Given the role of stathmin-1 in the destabilization of microtubles and taxane resistance, the Gγ-globin-Tag model and other SV40/T-antigen driven transgenic models may be useful for testing potential therapies directed at stathmin-1 in human prostate tumors.
prostate cancer; transgenic mouse; gene expression; microarrays; stathmin-1
The human 8-oxoguanine DNA glycosylase 1 (hOGG1), apurinic/apyrimidinic endonuclease 1 (APE1), and adenosine diphosphate ribosyl transferase (ADPRT) genes play an important role in the DNA base excision repair pathway. Single nucleotide polymorphisms (SNPs) in critical genes are suspected to be associated with the risk of lung cancer. This study aimed to identify the association between the polymorphisms of hOGG1 Ser326Cys, APE1 Asp148Glu, and ADPRT Val762Ala, and the risk of lung adenocarcinoma in the non-smoking female population, and investigated the interaction between genetic polymorphisms and environmental exposure in lung adenocarcinoma.
We performed a hospital-based case-control study, including 410 lung adenocarcinoma patients and 410 cancer-free hospital control subjects who were matched for age. Each case and control was interviewed to collect information by well-trained interviewers. A total of 10 ml of venous blood was collected for genotype testing. Three polymorphisms were analyzed by the polymerase chain reaction-restriction fragment length polymorphism technique.
We found that individuals who were homozygous for the variant hOGG1 326Cys/Cys showed a significantly increased risk of lung adenocarcinoma (OR = 1.54; 95% CI: 1.01–2.36; P = 0.045). When the combined effect of variant alleles was analyzed, we found an increased OR of 1.89 (95% CI: 1.24–2.88, P = 0.003) for lung adenocarcinoma individuals with more than one homozygous variant allele. In stratified analyses, we found that the OR for the gene-environment interaction between Ser/Cys and Cys/Cys genotypes of hOGG1 codon 326 and cooking oil fumes for the risk of lung adenocarcinoma was 1.37 (95% CI: 0.77–2.44; P = 0.279) and 2.79 (95% CI: 1.50–5.18; P = 0.001), respectively.
The hOGG1 Ser326Cys polymorphism might be associated with the risk of lung adenocarcinoma in Chinese non-smoking females. Furthermore, there is a significant gene-environment association between cooking oil fumes and hOGG1 326 Cys/Cys genotype in lung adenocarcinoma among female non-smokers.
What's known on the subject? and What does the study add?
The link between inflammation and cancer has long been reported and inflammation is thought to play a role in the pathogenesis of many cancers, including prostate cancer (PrCa). Over the last 5 years, genome-wide association studies (GWAS) have reported numerous susceptibility loci that predispose individuals to many different traits.The present study aims to ascertain if there are common genetic risk profiles that might predispose individuals to both PrCa and the autoimmune inflammatory condition, rheumatoid arthritis. These results could have potential public heath impact in terms of screening and chemoprevention.
To investigate if potential common pathways exist for the pathogenesis of autoimmune disease and prostate cancer (PrCa).To ascertain if the single nucleotide polymorphisms (SNPs) reported by genome-wide association studies (GWAS) as being associated with susceptibility to PrCa are also associated with susceptibility to the autoimmune disease rheumatoid arthritis (RA).
Materials and Methods
The original Wellcome Trust Case Control Consortium (WTCCC) UK RA GWAS study was expanded to include a total of 3221 cases and 5272 controls.In all, 37 germline autosomal SNPs at genome-wide significance associated with PrCa risk were identified from a UK/Australian PrCa GWAS.Allele frequencies were compared for these 37 SNPs between RA cases and controls using a chi-squared trend test and corrected for multiple testing (Bonferroni).
In all, 33 SNPs were able to be analysed in the RA dataset. Proxies could not be located for the SNPs in 3q26, 5p15 and for two SNPs in 17q12.After applying a Bonferroni correction for the number of SNPs tested, the SNP mapping to CCHCR1 (rs130067) retained statistically significant evidence for association (P = 6 × 10–4; odds ratio [OR] = 1.15, 95% CI: 1.06–1.24); this has also been associated with psoriasis.However, further analyses showed that the association of this allele was due to confounding by RA-associated HLA-DRB1 alleles.
There is currently no evidence that SNPs associated with PrCa at genome-wide significance are associated with the development of RA.Studies like this are important in determining if common genetic risk profiles might predispose individuals to many diseases, which could have implications for public health in terms of screening and chemoprevention.
genetic variants; genome-wide association studies (GWAS); prostate cancer; rheumatoid arthritis
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.
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.
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.
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.
prostate cancer; BRCA1 gene; mutation screening; cancer risk
Germline BRCA2 mutation is associated with increased prostate cancer (PrCa) risk. We have assessed survival in young PrCa cases with a germline mutation in BRCA2 and investigated loss of heterozygosity at BRCA2 in their tumours.
Two cohorts were compared: one was a group with young onset PrCa, tested for germline BRCA2 mutations (6/263 cases had a germline BRAC2 mutation), the validation set was a clinical set from Manchester of known BRCA2 mutuation carriers (15 cases) with PrCa. Survival data were compared with a control series of patients in a single clinic as determined by Kaplan-Meier estimates. Loss of heterozygosity was tested for in the DNA of tumour tissue of the young onset group by typing four micro-satellite markers which flanked the BRCA2 gene and then sequencing.
Median survival of all PrCa cases with a germline BRCA2 mutation, was shorter at 4.8 years than survival in controls at 8.5 years (p=0.002). Loss of heterozygosity was found in the majority of tumours of BRCA2 mutation carriers Multivariate analysis confirmed that the poorer survival of PrCa in BRCA2 mutation carriers is associated with the germline BRCA2 mutation per se.
BRCA2 germline mutation is an independent prognostic factor for survival in PrCa. Such patients should not be managed with active surveillance as they have more aggressive disease.
Prostate Cancer; BRCA2; Prognosis; Genetic Testing
The germline BRCA2 mutation is associated with increased prostate cancer (PrCa) risk. We have assessed survival in young PrCa cases with a germline mutation in BRCA2 and investigated loss of heterozygosity at BRCA2 in their tumours.
Two cohorts were compared: one was a group with young-onset PrCa, tested for germline BRCA2 mutations (6 of 263 cases had a germline BRAC2 mutation), and the second was a validation set consisting of a clinical set from Manchester of known BRCA2 mutuation carriers (15 cases) with PrCa. Survival data were compared with a control series of patients in a single clinic as determined by Kaplan–Meier estimates. Loss of heterozygosity was tested for in the DNA of tumour tissue of the young-onset group by typing four microsatellite markers that flanked the BRCA2 gene, followed by sequencing.
Median survival of all PrCa cases with a germline BRCA2 mutation was shorter at 4.8 years than was survival in controls at 8.5 years (P=0.002). Loss of heterozygosity was found in the majority of tumours of BRCA2 mutation carriers. Multivariate analysis confirmed that the poorer survival of PrCa in BRCA2 mutation carriers is associated with the germline BRCA2 mutation per se.
BRCA2 germline mutation is an independent prognostic factor for survival in PrCa. Such patients should not be managed with active surveillance as they have more aggressive disease.
prostate cancer; BRCA2; prognosis; genetic testing