ELAC2 polymorphisms and prostate cancer risk: a meta-analysis based on 18 case-control studies

Transfer RNAs as dynamic and critical regulators of cancer progression

Transfer RNAs (tRNAs) have been historically viewed as non-dynamic adaptors that decode the genetic code into proteins. Recent work has uncovered dynamic regulatory roles for these fascinating molecules. Advances in tRNA detection methods have revealed that specific tRNAs can become modulated upon DNA copy number and chromatin alterations and can also be perturbed by oncogenic signalling and transcriptional regulators in cancer cells or the tumour microenvironment. Such alterations in the levels of specific tRNAs have been shown to causally impact cancer progression, including metastasis. Moreover, sequencing methods have identified tRNA-derived small RNAs that influence various aspects of cancer progression, such as cell proliferation and invasion, and could serve as diagnostic and prognostic biomarkers or putative therapeutic targets in various cancers. Finally, there is accumulating evidence, including from genetic models, that specific tRNA synthetases - the enzymes responsible for charging tRNAs with amino acids - can either promote or suppress tumour formation. In this Review, we provide an overview of how deregulation of tRNAs influences cancer formation and progression.

Multi-omic profiling reveals an RNA processing rheostat that predisposes to prostate cancer

Prostate cancer is the most commonly diagnosed malignancy and the third leading cause of cancer deaths. GWAS have identified variants associated with prostate cancer susceptibility; however, mechanistic and functional validation of these mutations is lacking. We used CRISPR-Cas9 genome editing to introduce a missense variant identified in the ELAC2 gene, which encodes a dually localised nuclear and mitochondrial RNA processing enzyme, into the mouse Elac2 gene as well as to generate a prostate-specific knockout of Elac2. These mutations caused enlargement and inflammation of the prostate and nodule formation. The Elac2 variant or knockout mice on the background of the transgenic adenocarcinoma of the mouse prostate (TRAMP) model show that Elac2 mutation with a secondary genetic insult exacerbated the onset and progression of prostate cancer. Multiomic profiling revealed defects in energy metabolism that activated proinflammatory and tumorigenic pathways as a consequence of impaired noncoding RNA processing and reduced protein synthesis. Our physiologically relevant models show that the ELAC2 variant is a predisposing factor for prostate cancer and identify changes that underlie the pathogenesis of this cancer.

Carriage of Ser217Leu and Ala541Thr Variants of ELAC2 Gene and Risk Factors in Patients with Prostate Cancer in Burkina Faso

Background

Genetic factors are one of the significant contributors to prostate cancer (PCa) development, and hereditary prostate cancer 2 (HPC2) locus gene ELAC2 is considered a PCa susceptibility region. The HPC2/ELAC2 gene has been identified by linkage analysis in familial prostate cancer patients in the United States but has never been studied in Burkina Faso. The objective of the present study was to analyze the carriage of the C650T (Ser217Leu) and G1621A (Ala541Thr) mutations of the ELAC2 gene and the risk factors in prostate cancer patients in Burkina Faso.

Methods

This case-control study included 76 participants, including 38 histologically confirmed prostate cancer cases and 38 healthy controls without prostate abnormalities. PCR combined with restriction fragment length polymorphism (RFLP) was used to characterize the genotypes of the Ser217Leu and Ala541Thr polymorphisms of the ELAC2 gene. The correlations between the different genotypes and risk factors for prostate cancer were investigated.

Results

The C650T mutation was present in 44.73% of prostate cancer cases and 47.37% of controls. The G1621A mutation was present in 26.32% of prostate cancer cases and 15.79% of controls. We did not detect an association between prostate cancer risk and the Ser217Leu (p=0.972) and Ala541Thr (p=0.267) variants of the ELAC2 gene. Also, the two ELAC2 SNPs did not correlate with clinical stage, prostate-specific antigen (PSA) level at diagnosis, or the Gleason score on biopsies. However, we found that 100% of homozygous carriers of the T650 mutation have an A1621 mutation (p ≤ 0.001).

Conclusion

Ser217Leu and Ala541Thr polymorphisms of ELAC2, considered alone or in combination, are not associated with prostate cancer risk.

Prostate Cancer Review: Genetics, Diagnosis, Treatment Options, and Alternative Approaches

Simple Summary

Prostate cancer affects men of all racial and ethnic groups and leads to higher rates of mortality in those belonging to a lower socioeconomic status due to late detection of the disease. There is growing evidence that suggests the contribution of an individual’s genetic profile to prostate cancer. Currently used prostate cancer treatments have serious adverse effects; therefore, new research is focusing on alternative treatment options such as the use of genetic biomarkers for targeted gene therapy, nanotechnology for controlled targeted treatment, and further exploring medicinal plants for new anticancer agents. In this review, we describe the recent advances in prostate cancer research.

Abstract

Prostate cancer is one of the malignancies that affects men and significantly contributes to increased mortality rates in men globally. Patients affected with prostate cancer present with either a localized or advanced disease. In this review, we aim to provide a holistic overview of prostate cancer, including the diagnosis of the disease, mutations leading to the onset and progression of the disease, and treatment options. Prostate cancer diagnoses include a digital rectal examination, prostate-specific antigen analysis, and prostate biopsies. Mutations in certain genes are linked to the onset, progression, and metastasis of the cancer. Treatment for localized prostate cancer encompasses active surveillance, ablative radiotherapy, and radical prostatectomy. Men who relapse or present metastatic prostate cancer receive androgen deprivation therapy (ADT), salvage radiotherapy, and chemotherapy. Currently, available treatment options are more effective when used as combination therapy; however, despite available treatment options, prostate cancer remains to be incurable. There has been ongoing research on finding and identifying other treatment approaches such as the use of traditional medicine, the application of nanotechnologies, and gene therapy to combat prostate cancer, drug resistance, as well as to reduce the adverse effects that come with current treatment options. In this article, we summarize the genes involved in prostate cancer, available treatment options, and current research on alternative treatment options.

Classification of Homo sapiens gene behavior using linear discriminant analysis fused with minimum entropy mapping

Classification of Homo sapiens gene behavior employing computational biology is a recent research trend. But monitoring gene activity profile and genetic behavior from the alphabetic DNA sequence using a non-invasive method is a tremendous challenge in functional genomics. The present paper addresses such issue and attempts to differentiate Homo sapiens genes using linear discriminant analysis (LDA) method. Annotated protein coding sequences of Homo sapiens genes, collected from NCBI, are taken as test samples. Minimum entropy-based mapping (MEM) technique assists to extract highest information from the numerical DNA sequences. The proposed LDA technique has successfully classified Homo sapiens genes based on the following features: composition of hydrophilic amino acids, dominance of arginine amino acid, and magnitude and size of individual amino acids. The proposed algorithm is successfully tested on 84 Homo sapiens healthy and cancer genes of the prostate and breast cells. Classification performance of the proposed LDA technique is judged by sensitivity (89.12%), specificity (91.9%), accuracy (90.87%), F1 score (92.03%), Matthews' correlation coefficients (81.04%), and miss rate (9.12%), and it outperforms other four existing classifiers. The results are cross-validated through Rayleigh PDF and mutual information technique. Fisher test, 2-sample T-test, and relative entropy test are considered to verify the efficacy of the present classifier.

Identification of Homo sapiens cancer classes based on fusion of hidden gene features

Classification of Homo sapiens cancer genes in molecular level is a challenging research issue as they are extremely pseudo random in nature. Signature gene features need to be exposed to distinctly identify the gene class. Tree-structured filter bank is chosen to perform feature extraction and dimension reduction of the genes. Extracted gene features are fused using Gaussian mixture probability distribution function and identify different cancer classes depending on amount of correlation and exploiting maximum likelihood function. The algorithm is tested on 161 sample gene data of 7 different cancer classes. Sensitivity, specificity, accuracy, precision and F-score are used as metrics to judge the performance of the system and ROC is plotted in comparison with existing electrical network model based classifier. The proposed classifier can identify more than stated number of cancer classes which is a major limitation of the existing electrical network based method. The proposed algorithm is validated by comparing the results with other seven existing image processing based methods.

A Study of Ser217Leu and Ala541Thr Polymorphism in the Men Afflicted with Prostate Cancer and in the Men being Suspicious of Prostate Cancer

Background and objective:

Prostate cancer is one of the most widespread cancers among men throughout the world. In addition, it is the second cause of death after lung cancer. Occurrence of the prostate cancer is variable in various regions of the world. Solely, there are three known risk factors for the prostate cancer, including: Age, inheritance and ethnic origin. ELAC2 protein is a phosphodiesterase enzyme encoded by ELAC2 gene in human. This gene is placed on chromosome 17, and it is believed that product of the mentioned gene is an endonuclease contributed in puberty of mitochondrion’s tRNA. From clinical viewpoint, variables of ELAC2 gene such as Ser217Leu and Ala541Thr Missense mutations which are accompanied by hereditary prostate cancer (HPC2).Objective of this study is to investigate Ser217Leu (rs4792311) and Ala541Thr (rs5030739) polymorphisms in the individuals with prostate cancer or those who are suspicious of prostate cancer with family past record/history.

Study method:

In this study conducted by case-control method in 2018, 102 men with prostate cancer and 98 men being suspicious of prostate cancer out of 10 families referred to shahid Rajaei Hospital in Tonekabon county to study and check were investigated. After collection of data using questionnaire, sampling from individuals and performance of the rest steps, study of polymorphism was carried out by PCR sequencing technique, and the results were analyzed by Chromas software.

Finding:

Of the total studied 102 individuals, 44 individuals (43.1%) were homozygote for Ser217Leu mutation, 36 individuals (35.2%) were heterozygote and 22 individuals (21.5%) lacked Missense mutation. for Ala541Thr mutation, 18 ones (17.6%) were heterozygote and 84 ones (82.3%) lacked Missense mutation. For Ser217Leu mutation, out of 98 suspicious individuals, 21 individuals (21.4%) were homozygote. 6 individuals (6.1%) were heterozygote and 71 individuals (72.4%) lacked the mutation. For Ala541Thr mutation, 15 ones (15.3%) were homozygote and 84 ones (84.6%) lacked the studied mutation.

Conclusion:

Results of this research showed that, in the individuals with the prostate cancer, there is a relationship between Ser217Leu and Ala541Thr polymorphism of ELAC2 gene and/with prostate cancer, and the suspicious individuals gotten involved in the mutation must take action to prevent this cancer.

Nuclear ELAC2 overexpression is associated with increased hazard for relapse after radical prostatectomy

ELAC2 is a ubiquitously expressed enzyme potentially involved in tRNA processing and cell signaling pathways. Mutations of the ELAC2 gene have been found to confer increased prostate cancer susceptibility in families. ELAC2 protein expression was analyzed by immunohistochemistry in 9,262 patients and Kaplan-Meier curves of PSA recurrence-free survival were calculated in 8,513 patients treated with radical prostatectomy. Nuclear ELAC2 staining was observed in 60.8% of prostate cancers. It was weak in 26.3%, moderate in 26.6% and strong in 7.9%. Strong nuclear ELAC2 expression was associated with advanced tumor stage, nodal metastasis, higher Gleason grade, presence of TMPRSS2:ERG fusion, higher Ki67-labeling index and PTEN deletion. The difference in 1-, 5- and 10-year recurrence-free survival between strong and weak nuclear ELAC2 intensity is 7.2/13.8/17.6% in all cancers, 7.4/16.1/26.5% in the ERG negative subset, and 3.1/5.7/9.8% in the ERG positive subset. Regarding the univariate hazard ratio, PSA recurrence-free survival after prostatectomy for strong nuclear ELAC2 expression is 1.89 (1.64–2.10, p < 0.0001). It is independent of preoperative PSA-level, Gleason grade, pathological stage, surgical margin stage, and lymph node stage (multivariate hazard ratio 1.29 (1.11–1.49, p = 0.001). We conclude that nuclear ELAC2 expression is an independent prognostic marker for PSA recurrence-free survival after radical prostatectomy with a weak to moderate increase of the hazard ratio for biochemical relapse.

Prevalence of the Ser217Leu Variant of the ELAC2 Gene and Its Association with Prostate Cancer in Population of the Littoral Region of Cameroon

Background. HPC2/ELAC2 has been identified as a prostate cancer (PC) susceptibility gene. Ser- Leu changes at amino acid 217 have been one of the most studied variants of this gene. Several reports have shown association of this variant with PC in samples of men drawn from families with hereditary PC and even sporadic cases. Aim. This study aimed at assessing this association and the prevalence of the Ser217Leu variant of ELAC2 in populations of the Littoral Region of Cameroon. Method. 103 PC case subjects and 80 randomly selected controls identified from the study population participated in the study. 2 milliliters of blood samples was collected from each of the consented participants and used for human genomic DNA extraction and genotyping of the ELAC2 gene by the nonenzymatic salting out and PCR-RFLP methods, respectively. Results. The frequencies of the wild type (SS), heterozygous mutant (SL), and homozygous mutant (LL) genotypes were, respectively, 28.2%, 49.5%, and 22.3% in prostate cancer patients and 28.8%, 67.5%, and 3.7% in controls. Comparing the LL with SS and (SL+LL) with SS showed that the presence of two copies of the L allele confers a high risk of prostate cancer as compared to the presence of only one L allele which presents no risk of prostate cancer (OR = 6.080 and 1.030, respectively). Analysis of our results also suggested an association (P = 0.0012) of the Ser217Leu variant with increased risk of prostate cancer. Conclusion. Alterations in the ELAC2 gene contribute to prostate cancer susceptibility in men living in the Littoral Region of Cameroon.

Passive-specific immunotherapy with monoclonal antibodies for prostate cancer: A systematic review

Introduction

Treatment of metastatic castration-resistant prostate cancer with conventional therapies is still not successful. Therefore, application of novel biological approaches such as immunotherapy, which appears to be more effective and less toxic, is necessary. Monoclonal antibodies against cancer specific antigens are a kind of immunotherapy that have been approved for specific types of cancer and are being investigated for prostate cancer as well. The aim of this review was to assess the effectiveness and safety of monoclonal antibodies for treatment of advanced prostate cancer.

Method

According to the search strategy stated in our systematic review protocol, Scopus, Medline, TRIP, CENTRAL, ProQuest, DART and OpenGrey databases were searched. Data collection and quality assessment were done independently by two authors and any disagreements between the collected data were resolved by a third author. A meta-analysis was not feasible as there was a considerable statistical heterogeneity among the trials. Hence, this review was limited to a narrative analysis of the included studies.

Results

We found 9756 references by applying search strategy in 4 databases of journal articles and 3 databases of grey literature. We then discarded 3957 duplicate citations using Endnote software and 5143 articles due to obvious irrelevancy of their topics in primary screening. In secondary screening of 656 fulltexts, we excluded 538 articles, and finally included 12 trials in this systematic review, updated on 23 June 2017. The overall quality of the studies was fair. In general, results of this systematic review show promising advances in the treatment of prostate cancer patients with monoclonal antibodies against prostate-specific antigens with regard to PSA/disease response. Some of the studies reported pain relief after treatment as well.

Conclusion

Currently, the role of immunotherapy in the treatment of advanced prostate cancer still remains debated. Although passive specific immunotherapy could be offered as a novel therapeutic option in the coming years, patients should be informed about the risks and benefits of this therapy. One of the obstacles in this review was the lack of adequate assessment of survival-related endpoints reported in the included studies. Our study provides support for further research in this field.

Prostate Cancer Genomics: Recent Advances and the Prevailing Underrepresentation from Racial and Ethnic Minorities

Prostate cancer (CaP) is the most commonly diagnosed non-cutaneous cancer and the second leading cause of male cancer deaths in the United States. Among African American (AA) men, CaP is the most prevalent malignancy, with disproportionately higher incidence and mortality rates. Even after discounting the influence of socioeconomic factors, the effect of molecular and genetic factors on racial disparity of CaP is evident. Earlier studies on the molecular basis for CaP disparity have focused on the influence of heritable mutations and single-nucleotide polymorphisms (SNPs). Most CaP susceptibility alleles identified based on genome-wide association studies (GWAS) were common, low-penetrance variants. Germline CaP-associated mutations that are highly penetrant, such as those found in HOXB13 and BRCA2, are usually rare. More recently, genomic studies enabled by Next-Gen Sequencing (NGS) technologies have focused on the identification of somatic mutations that contribute to CaP tumorigenesis. These studies confirmed the high prevalence of ERG gene fusions and PTEN deletions among Caucasian Americans and identified novel somatic alterations in SPOP and FOXA1 genes in early stages of CaP. Individuals with African ancestry and other minorities are often underrepresented in these large-scale genomic studies, which are performed primarily using tumors from men of European ancestry. The insufficient number of specimens from AA men and other minority populations, together with the heterogeneity in the molecular etiology of CaP across populations, challenge the generalizability of findings from these projects. Efforts to close this gap by sequencing larger numbers of tumor specimens from more diverse populations, although still at an early stage, have discovered distinct genomic alterations. These research findings can have a direct impact on the diagnosis of CaP, the stratification of patients for treatment, and can help to address the disparity in incidence and mortality of CaP. This review examines the progress of understanding in CaP genetics and genomics and highlight the need to increase the representation from minority populations.

Beyond the Ribosome: Extra-translational Functions of tRNA Fragments

High-throughput sequencing studies of small RNAs reveal a complex milieu of noncoding RNAs in biological samples. Early data analysis was often limited to microRNAs due to their regulatory nature and potential as biomarkers; however, many more classes of noncoding RNAs are now being recognized. A class of fragments initially excluded from analysis were those derived from transfer RNAs (tRNAs) because they were thought to be degradation products. More recently, critical cellular function has been attributed to tRNA fragments (tRFs), and their conservation across all domains of life has propelled them into an emerging area of scientific study. The biogenesis of tRFs is currently being elucidated, and initial studies show that a diverse array of tRFs are generated from all parts of a tRNA molecule. The goal of this review was to present what is currently known about tRFs and their potential as biomarkers for the earlier detection of disease.

Genome-wide association study of myelosuppression in non-small-cell lung cancer patients with platinum-based chemotherapy

Platinum-induced myelosuppression severely impedes successful chemotherapy in non-small-cell lung cancer (NSCLC) patients. Hence, it is clinically important to identify the patients who are at high risk for severe toxicity to certain chemotherapy. We first carried out a genome-wide scan of 906 703 single-nucleotide polymorphisms (SNPs) to identify genetic variants associated with platinum-induced myelosuppression risk in 333 NSCLC patients with chemotherapy. Then, we replicated 24 SNPs that had P<1 × 10(-4) in another independent cohort of 876 NSCLC patients. With P<0.05 as the criterion of statistical significance, we found that rs13014982 at 2q24.3 and rs9909179 at 17p12 exhibited consistently significant associations with myelosuppression risk in both the genome-wide association studies (GWAS) scan and the replication stage (rs13014982: odds ratio (OR)=0.55, 95% confidence intervals (CIs): 0.41-0.74, P=7.29 × 10(-5) for GWAS scan and OR=0.77, 95% CI: 0.65-0.93, P=0.006 for replication stage; rs9909179: OR=0.51, 95% CI: 0.37-0.70, P=4.60 × 10(-5) for GWAS scan and OR=0.82, 95% CI: 0.68-0.99, P=0.040 for replication stage; both in additive model). In combined samples of genome-wide scan and replication samples, the minor alleles of rs13014982 and rs9909179 remained significant associations with the decreased risk of myelosuppression (rs13014982: OR=0.71, 95% CI: 0.61-0.83, P =1.36 × 10(-5); rs9909179: OR=0.76, 95% CI: 0.65-0.89, P=0.001). Rs13014982 at 2q24.3 and rs9909179 at 17p12 might be independent susceptibility markers for platinum-induced myelosuppression risk in NSCLC patients.

Prostate Cancer Genetics: A Review

Over the past decades, research has focussed on identifying the genetic underpinnings of prostate cancer. It has been recognized that a number of forms of genetic changes coupled with epigenetic and gene expression changes can increase the prediction to develop prostate cancer. This review outlines the role of somatic copy number alterations (SCNAs), structural rearrangements, point mutations, and single nucleotide polymorphisms (SNPs) as well as miRNAs. Identifying relevant genetic changes offers the ability to develop novel biomarkers to allow early and accurate detection of prostate cancer as well as provide risk stratification of patients following their diagnosis. The concept of personalized or individualized medicine has gained significant attention. Therefore, a better understanding of the genetic and metabolic pathways underlying prostate cancer development offers the opportunity to explore new therapeutic interventions with the possibility of offering patient-specific targeted therapy.

Systematic review and meta-analysis of candidate gene association studies of lower urinary tract symptoms in men

Context

Although family studies have shown that male lower urinary tract symptoms (LUTS) are highly heritable, no systematic review exists of genetic polymorphisms tested for association with LUTS.

Objective

To systematically review and meta-analyze studies assessing candidate polymorphisms/genes tested for an association with LUTS, and to assess the strength, consistency, and potential for bias among pooled associations.

Evidence acquisition

A systematic search of the PubMed and HuGE databases as well as abstracts of major urologic meetings was performed through to January 2013. Case-control studies reporting genetic associations in men with LUTS were included. Reviewers independently and in duplicate screened titles, abstracts, and full texts to determine eligibility, abstracted data, and assessed the credibility of pooled associations according to the interim Venice criteria. Authors were contacted for clarifications if needed. Meta-analyses were performed for variants assessed in more than two studies.

Evidence synthesis

We identified 74 eligible studies containing data on 70 different genes. A total of 35 meta-analyses were performed with statistical significance in five (ACE, ELAC2, GSTM1, TERT, and VDR). The heterogeneity was high in three of these meta-analyses. The rs731236 variant of the vitamin D receptor had a protective effect for LUTS (odds ratio: 0.64; 95% confidence interval, 0.49–0.83) with moderate heterogeneity (I² = 27.2%). No evidence for publication bias was identified. Limitations include wide-ranging phenotype definitions for LUTS and limited power in most meta-analyses to detect smaller effect sizes.

Conclusions

Few putative genetic risk variants have been reliably replicated across populations. We found consistent evidence of a reduced risk of LUTS associated with the common rs731236 variant of the vitamin D receptor gene in our meta-analyses.

Patient summary

Combining the results from all previous studies of genetic variants that may cause urinary symptoms in men, we found significant variants in five genes. Only one, a variant of the vitamin D receptor, was consistently protective across different populations.

ELAC2 mutations cause a mitochondrial RNA processing defect associated with hypertrophic cardiomyopathy

The human mitochondrial genome encodes RNA components of its own translational machinery to produce the 13 mitochondrial-encoded subunits of the respiratory chain. Nuclear-encoded gene products are essential for all processes within the organelle, including RNA processing. Transcription of the mitochondrial genome generates large polycistronic transcripts punctuated by the 22 mitochondrial (mt) tRNAs that are conventionally cleaved by the RNase P-complex and the RNase Z activity of ELAC2 at 5' and 3' ends, respectively. We report the identification of mutations in ELAC2 in five individuals with infantile hypertrophic cardiomyopathy and complex I deficiency. We observed accumulated mtRNA precursors in affected individuals muscle and fibroblasts. Although mature mt-tRNA, mt-mRNA, and mt-rRNA levels were not decreased in fibroblasts, the processing defect was associated with impaired mitochondrial translation. Complementation experiments in mutant cell lines restored RNA processing and a yeast model provided additional evidence for the disease-causal role of defective ELAC2, thereby linking mtRNA processing to human disease.

Ethnical disparities of prostate cancer predisposition: genetic polymorphisms in androgen-related genes

Prostate cancer (PCa) is the most commonly diagnosed male malignancy and the second biggest cause of cancer death in men of the Western world. Higher incidences of PCa occur in men from North America, Oceania and Western countries, whereas men from Asia and North Africa have a much lower PCa incidence rate. Investigations into this population disparity of PCa incidence, in order to identify potential preventive factors or targets for the therapeutic intervention of PCa, have found differences in both environmental and genetic variations between these populations. Environmental variations include both diet and lifestyle, which vary widely between populations. Evidence that diet comes into play has been shown by men who immigrate from Eastern to Western countries. PCa incidence in these men is higher than men in their native countries. However the number of immigrants developing PCa still doesn't match native black/white men, therefore genetic factors also contribute to PCa risk, which are supported by familial studies. There are a number of genetic polymorphisms that are differentially presented between Western and Eastern men, which are potentially associated with PCa incidence. Androgen and its receptor (AR) play a major role in PCa development and progression. In this study, we focus on genes involved in androgen biosynthesis and metabolism, as well as those associated with AR pathway, whose polymorphisms affect androgen level and biological or physiological functions of androgen. While many of the genetic polymorphisms in this androgen/AR system showed different frequencies between populations, contradictory evidences exist for most of these genes investigated individually as to the true contribution to PCa risk. More accurate measurements of androgen activity within the prostate are required and further studies need to include more African and Asian subjects. As many of these genetic polymorphisms may contribute to different steps in the same biological/physiological function of androgen and AR pathway, an integrated analysis considering the combined effect of all the genetic polymorphisms may be necessary to assess their contribution to PCa initiation and progression.

Association of the PTPN22 gene (+1858C/T, -1123G/C) polymorphisms with type 1 diabetes mellitus: a systematic review and meta-analysis

OBJECTIVE

A meta-analysis was conducted to evaluate the association of PTPN22 gene (+1858C/T -1123G/C) polymorphism with T1DM susceptibility.

METHODS

Electronic databases were used to identify published studies before September 2011. We adopted the most appropriate genetic model. The combined odds ratio (OR) with 95% confidence interval (95% CI) was calculated to estimate the strength of the association in a fixed or random effect model. Heterogeneity and publication bias were also assessed.

RESULTS

Totally, 25 case-control studies including 8613 T1DM cases and 10,133 healthy controls (24 studies containing 8129 cases and 9641 controls for PTPN22 +1858C/T, 5 studies including 1460 cases and 1609 controls for PTPN22 -1123G/C) were identified as eligible and analyzed. The most appropriate co-dominant model was adopted. A significant association of PTPN22 +1858C/T gene polymorphism was found in overall population. When stratified by race, significance was observed in Europe and America, but not in Asia. We did not detect any association for PTPN22 -1123G/C polymorphism.

CONCLUSIONS

Our study indicated that T1DM is associated with PTPN22 +1858C/T gene polymorphism, and targeting this promoter polymorphism should be dependent on ethnicity. Whether -1123G/C polymorphism is a susceptibility locus for T1DM, further studies with well-designed among different ethnicity populations are required.

East meets West: ethnic differences in prostate cancer epidemiology between East Asians and Caucasians

Prostate cancer is the most prevalent cancer in males in Western countries. The reported incidence in Asia is much lower than that in African Americans and European Caucasians. Although the lack of systematic prostate cancer screening system in Asian countries explains part of the difference, this alone cannot fully explain the lower incidence in Asian immigrants in the United States and west-European countries compared to the black and non-Hispanic white in those countries, nor the somewhat better prognosis in Asian immigrants with prostate cancer in the United States. Soy food consumption, more popular in Asian populations, is associated with a 25% to 30% reduced risk of prostate cancer. Prostate-specific antigen (PSA) is the only established and routinely implemented clinical biomarker for prostate cancer detection and disease status. Other biomarkers, such as urinary prostate cancer antigen 3 RNA, may increase accuracy of prostate cancer screening compared to PSA alone. Several susceptible loci have been identified in genetic linkage analyses in populations of countries in the West, and approximately 30 genetic polymorphisms have been reported to modestly increase the prostate cancer risk in genome-wide association studies. Most of the identified polymorphisms are reproducible regardless of ethnicity. Somatic mutations in the genomes of prostate tumors have been repeatedly reported to include deletion and gain of the 8p and 8q chromosomal regions, respectively; epigenetic gene silencing of glutathione S-transferase Pi (GSTP1); as well as mutations in androgen receptor gene. However, the molecular mechanisms underlying carcinogenesis, aggressiveness, and prognosis of prostate cancer remain largely unknown. Gene-gene and/or gene-environment interactions still need to be learned. In this review, the differences in PSA screening practice, reported incidence and prognosis of prostate cancer, and genetic factors between the populations in East and West factors are discussed.

EphB2 SNPs and sporadic prostate cancer risk in African American men

The EphB2 gene has been implicated as a tumor suppressor gene somatically altered in both prostate cancer (PC) and colorectal cancer. We have previously shown an association between an EphB2 germline nonsense variant and risk of familial prostate cancer among African American Men (AAM). Here we set out to test the hypothesis that common variation within the EphB2 locus is associated with increased risk of sporadic PC in AAM. We genotyped a set of 341 single nucleotide polymorphisms (SNPs) encompassing the EphB2 locus, including known and novel coding and noncoding variants, in 490 AA sporadic PC cases and 567 matched controls. Single marker-based logistical regression analyses revealed seven EphB2 SNPs showing statistically significant association with prostate cancer risk in our population. The most significant association was achieved for a novel synonymous coding SNP, TGen-624, (Odds Ratio (OR)  = 0.22; 95% Confidence Interval (CI) 0.08-0.66, p = 1×10(-5)). Two other SNPs also show significant associations toward a protective effect rs10465543 and rs12090415 (p = 1×10(-4)), OR = 0.49 and 0.7, respectively. Two additional SNPs revealed trends towards an increase in risk of prostate cancer, rs4612601 and rs4263970 (p = 0.001), OR = 1.35 and 1.31, respectively. Furthermore, haplotype analysis revealed low levels of linkage disequilibrium within the region, with two blocks being associated with prostate cancer risk among our population. These data suggest that genetic variation at the EphB2 locus may increase risk of sporadic PC among AAM.