Prostate cancer susceptibility variants confer increased risk of disease progression

Single nucleotide polymorphism within chromosome 8q24 is associated with prostate cancer development in Saudi Arabia

Objective

Genome-wide association studies have demonstrated that single nucleotide polymorphisms (SNPs) are important risk factors for the development of prostate cancer (PCa). Preliminary studies have suggested that the incidence of PCa in Saudi males is low but is probably familial or genetically related.

Methods

To identify any possible association of SNP with PCa development in Saudi patients, we investigated a group of SNPs in Saudi PCa patients (n=85) and compared the outcomes to healthy normal controls (n=115) and nodular hyperplasia patients (n=120). DNA was extracted from paraffin-embedded formalin fixed tissue or whole blood from both patients' groups and healthy control group. A total of thirteen SNPs were genotyped using TaqMan® minor groove binder polymerase chain reaction assay.

Results

The rs16901979A, s629242T and rs1447295A alleles were found at significantly higher frequency in PCa patients than controls (p<0.05). The rs16901979 CA genotype was found at significantly greater frequency in PCa patients than in healthy controls (43% vs. 14%, odds ratio=4.6, p=0.0001) and benign hyperplasia group (43% vs. 25%, odds ratio=2.2, p=0.009).

Conclusion

Our study has highlighted the association of rs16901979 SNP with PCa in Saudi males. Such findings have important implications in the PCa diagnosis and in screening unaffected family members of Saudi patients.

Regulation of Kinase Signaling Pathways by α6β4-Integrins and Plectin in Prostate Cancer

Hemidesmosomes (HDs) are adhesive structures that ensure stable anchorage of cells to the basement membrane. They are formed by α6β4-integrin heterodimers and linked to intermediate filaments via plectin. It has been reported that one of the most common events during the pathogenesis of prostate cancer (PCa) is the loss of HD organization. While the expression levels of β4-integrins are strongly reduced, the expression levels of α6-integrins and plectin are maintained or even elevated, and seem to promote tumorigenic properties of PCa cells, such as proliferation, invasion, metastasis, apoptosis- and drug-resistance. In this review, we discuss the potential mechanisms of how HD components might contribute to various cellular signaling pathways to promote prostate carcinogenesis. Moreover, we summarize the current knowledge on the involvement of α6β4-integrins and plectin in PCa initiation and progression.

Genetic variant located on chromosome 17p12 contributes to prostate cancer onset and biochemical recurrence

The genetic contribution to prostate cancer (PC) onset and clinical heterogeneity has an important impact on the disease stratification accuracy. Despite the fact that radical prostatectomy (RP) is an effective treatment for localized PC, a considerable number of individuals develop biochemical recurrence (BCR) following surgery. In the present study, we decided to investigate the significance of genetic variability in a homogeneous group of Romanian men and to determine if genotyping could provide information regarding the possible implications of rs4054823 susceptibility loci in PC progression and outcome. A total of 78 samples from both PC and benign prostatic hyperplasia (BPH) patients were genotyped. The genotype frequencies were examined to see if there was a link between the 17p12 SNP and PC disease. When compared to the BPH group, the PC group had a significantly higher frequency of the T risk variant (P = 0.0056) and TT genotype (P = 0.0164). Subsequent analysis revealed that the TT genotype had a significantly higher frequency among younger PC patients based on their age at diagnosis and that it was related with a greater probability of BCR (P = 0.02). According to our findings, the TT genotype appears to be a risk factor for early-onset PC and a potential predictor for BCR after RP.

Potential functional variants of KIAA genes are associated with breast cancer risk in a case control study

Background

KIAA genes identified in the Kazusa cDNA-sequencing project may play important roles in biological processes and are involved in carcinogenesis of many cancers. Genetic variants of KIAA genes are implicated in the abnormal expression of these genes and are linked to susceptibility of several human complex diseases.

Methods

The differentially expressed KIAA genes were screened and identified in The Cancer Genome Atlas (TCGA) database of breast cancer. A total of 48 variants located in the 28 KIAA genes were selected to investigate the associations between polymorphism and breast cancer in 1,032 cases and 1,063 cancer-free controls in a Chinese population.

Results

Two coding variants, which included a SNP rs2306369 in KIAA1109 and a SNP rs1205434 in KIAA1755, were identified to be associated with the incidences of breast cancer. Logistic regression analysis showed that the SNP rs2306369 G allele was associated with a decreased risk of breast cancer (additive model: OR =0.81, 95% CI: 0.66-0.99, P=0.038), whereas the SNP rs1205434 A allele was involved with a higher risk of breast cancer (additive model: OR =1.19, 95% CI: 1.02-1.38, P= 0.025). Further stratified analysis revealed that the SNP rs1205434 showed a significant difference for age at menarche strata (heterogeneity test P=0.009). Multiplicative interaction analysis indicated that there was positive multiplicative interaction between the SNP rs1205434 and menarche age (OR =1.09, 95% CI: 1.01-1.17, P=0.036). Additionally, expression quantitative trait loci analysis revealed that the SNP rs1205434 A allele could decrease the KIAA1755 expression in the Genotype-Tissue Expression (GTEx) database (P=0.002). The Kaplan-Meier plotter showed that breast cancer patients with high KIAA1755 expression have significantly better outcomes than those with low levels of expression (HR =0.84, 95% CI: 0.72-0.99, P=0.033).

Conclusions

The results indicate that the genetic variants (rs2306369 and rs1205434) in the coding region of KIAA1109 and KIAA1755 respectively may affect Chinese females' breast cancer susceptibility and act as potential predictive biomarkers for breast cancer.

Impact of GAS5 genetic polymorphism on prostate cancer susceptibility and clinicopathologic characteristics

Down-regulation of Growth arrest-specific 5 (GAS5) is correlated with enhanced cell proliferation and poorer prognosis of prostate cancer. We aimed to investigate the effect of variant rs145204276 of GAS5 on the prostate cancer susceptibility and clinicopathologic characteristics. In this study, 579 prostate cancer patients who underwent robot-assisted radical prostatectomy and 579 healthy controls were included. The frequency of the allele del of rs145204276 were compared between the patients and the controls to evaluate the impact of tumor susceptibility and the correlation of clinicopathological variables. The results shown that patients who carries genotype ins/del or del/del at SNP rs145204276 showed decreased risk of pathological lymph node metastasis disease (OR=0.545, p=0.043) and risk of seminal vesicle invasion (OR=0.632, p=0.022) comparing to with genotype ins/ins. In the subgroup analysis of age, more significant risk reduction effects were noted over lymph node metastasis disease (OR=0.426, p=0.032) and lymphovascular invasion (OR=0.521, p=0.025). In conclusion, the rs145204276 polymorphic genotype of GAS5 can predict the risk of lymph node metastasis. This is the first study to report the correlation between GAS5 gene polymorphism and prostate cancer prognosis.

Systematic identification of functionally relevant risk alleles to stratify aggressive versus indolent prostate cancer

Novel approaches for classification, including molecular features, are needed to direct therapy for men with low-grade prostate cancer (PCa), especially men on active surveillance. Risk alleles identified from genome-wide association studies (GWAS) could improve prognostication. Those risk alleles that coincided with genes and somatic copy number aberrations associated with progression of PCa were selected as the most relevant for prognostication.

In a systematic literature review, a total of 698 studies were collated. Fifty-three unique SNPs residing in 29 genomic regions, including 8q24, 10q11 and 19q13, were associated with PCa progression. Functional studies implicated 21 of these single nucleotide polymorphisms (SNPs) as modulating the expression of genes in the androgen receptor pathway and several other oncogenes. In particular, 8q24, encompassing MYC, harbours a high density of SNPs conferring unfavourable pathological characteristics in low-grade PCa, while a copy number gain of MYC in low-grade PCa was associated with prostate-specific antigen recurrence after radical prostatectomy.

By combining GWAS data with gene expression and structural rearrangements, risk alleles were identified that could provide a new basis for developing a prognostication tool to guide therapy for men with early prostate cancer.

Influence of Adalimumab on the Expression Profile of Genes Associated with the Histaminergic System in the Skin Fibroblasts In Vitro

Objective

The aim of this study was to evaluate the influence of adalimumab on expression profile of genes associated with the histaminergic system in Normal Human Dermal Fibroblast (NHDF) cells stimulated with 8.00 μg/ml of adalimumab and the identification of miRNAs regulating these genes' expression.

Methods

NHDFs were cultured with or without the presence of adalimumab for 2, 8, and 24 hours. The expression profile of genes and miRNA were determined with the use of microarray technology.

Results

Among 22283 ID mRNA, 65 are associated with the histaminergic system. It can be observed that 15 mRNAs differentiate NHDFs cultures with adalimumab form control. The analysis of miRNAs showed that, among 1105 ID miRNA, 20 miRNAs are differentiating in cells treated with adalimumab for 2 hours, 9 miRNA after 8 hours, and only 3 miRNAs after 24 hours.

Conclusion

It was also determined that miRNAs play certain role in the regulation of the expression of genes associated with the histaminergic system. The results of this study confirmed the possibility of using both genes associated with this system as well as miRNAs regulating their expression, as complementary molecular markers of sensitivity to the adalimumab treatment.

Significantly mutated genes and regulatory pathways in SCLC-a meta-analysis

Small cell lung cancer (SCLC) accounts for approximately 15% of all lung cancers and demands effective targeted therapeutic strategies. In this meta-analysis study, we aim to identify significantly mutated genes and regulatory pathways to help us better understand the progression of SCLC and to identify potential biomarkers. Besides ranking genes based on their mutation frequencies, we sought to identify statistically significant mutations in SCLC with the MutSigCV software. Our analysis identified several genes with relatively low mutation frequency, including PTEN, as highly significant (p < 0.001), suggesting these genes may play an important role in the progression of SCLC. Our results also indicated mutations in genes involved in the axon guidance pathways likely play an important role in SCLC progression. In addition, we observed that the mutation rate was significantly higher in samples with RB1 gene mutated when compared to samples with wild type RB1, suggesting that RB1 status has significant impact on the mutation profile and disease progression in SCLC.

Transcriptomic comparison of primary bovine horn core carcinoma culture and parental tissue at early stage

Aim:

Squamous cell carcinoma or SCC of horn in bovines (bovine horn core carcinoma) frequently observed in Bos indicus affecting almost 1% of cattle population. Freshly isolated primary epithelial cells may be closely related to the malignant epithelial cells of the tumor. Comparison of gene expression in between horn’s SCC tissue and its early passage primary culture using next generation sequencing was the aim of this study.

Materials and Methods:

Whole transcriptome sequencing of horn’s SCC tissue and its early passage cells using Ion Torrent PGM were done. Comparative expression and analysis of different genes and pathways related to cancer and biological processes associated with malignancy, proliferating capacity, differentiation, apoptosis, senescence, adhesion, cohesion, migration, invasion, angiogenesis, and metabolic pathways were identified.

Results:

Up-regulated genes in SCC of horn’s early passage cells were involved in transporter activity, catalytic activity, nucleic acid binding transcription factor activity, biogenesis, cellular processes, biological regulation and localization and the down-regulated genes mainly were involved in focal adhesion, extracellular matrix receptor interaction and spliceosome activity.

Conclusion:

The experiment revealed similar transcriptomic nature of horn’s SCC tissue and its early passage cells.

Rare Variation in TET2 Is Associated with Clinically Relevant Prostate Carcinoma in African Americans

BACKGROUND

Common variants have been associated with prostate cancer risk. Unfortunately, few are reproducibly linked to aggressive disease, the phenotype of greatest clinical relevance. One possible explanation is that rare genetic variants underlie a significant proportion of the risk for aggressive disease.

METHOD

To identify such variants, we performed a two-stage approach using whole-exome sequencing followed by targeted sequencing of 800 genes in 652 aggressive prostate cancer patients and 752 disease-free controls in both African and European Americans. In each population, we tested rare variants for association using two gene-based aggregation tests. We established a study-wide significance threshold of 3.125 × 10-5 to correct for multiple testing.

RESULTS

TET2 in African Americans was associated with aggressive disease, with 24.4% of cases harboring a rare deleterious variant compared with 9.6% of controls (FET P = 1.84 × 10-5, OR = 3.0; SKAT-O P = 2.74 × 10-5). We report 8 additional genes with suggestive evidence of association, including the DNA repair genes PARP2 and MSH6 Finally, we observed an excess of rare truncation variants in 5 genes, including the DNA repair genes MSH6, BRCA1, and BRCA2 This adds to the growing body of evidence that DNA repair pathway defects may influence susceptibility to aggressive prostate cancer.

CONCLUSIONS

Our findings suggest that rare variants influence risk of clinically relevant prostate cancer and, if validated, could serve to identify men for screening, prophylaxis, and treatment.

IMPACT

This study provides evidence that rare variants in TET2 may help identify African American men at increased risk for clinically relevant prostate cancer. Cancer Epidemiol Biomarkers Prev; 25(11); 1456-63. ©2016 AACR.

Evaluation of human epidermal growth factor receptor 2 (HER2) single nucleotide polymorphisms (SNPs) in normal and breast tumor tissues and their link with breast cancer prognostic factors

Amplification of the human epidermal growth factor receptor 2 (HER2) gene is associated with worse prognosis and decreased overall survival in breast cancer patients. The HER2 gene contains several polymorphisms; two of the best-characterized HER2 polymorphisms are Ile655Val and Ala1170Pro. The aim of this study was to evaluate the association between these two HER2 polymorphisms in normal breast and breast cancer tissues and known breast cancer prognostic factors in a retrospective cohort study of 73 women with non-metastatic HER2-positive breast cancer. HER2 polymorphisms were assessed in breast cancer tissue and normal breast tissue using TaqMan assay. Ala1170Pro polymorphism in normal breast tissue was associated with age at diagnosis (p = 0.007), tumor size (p = 0.004) and lymphovascular invasion (p = 0.06). Similar significant associations in cancer tissues were observed. No association between the Ile655Val polymorphism and prognostic factors were observed. However, we found significant differences in the distribution of Ile655Val (p = 0.03) and Ala1170Pro (p = 0.01) genotypes between normal breast and breast tumor tissues. This study demonstrates that only the Ala1170Pro polymorphism is associated with prognostic factors in HER2-positive breast cancer patients. Moreover, our results suggest that both HER2 polymorphisms could play a significant role in carcinogenesis in non-metastatic HER2-positive breast cancer women.

The identification of trans-associations between prostate cancer GWAS SNPs and RNA expression differences in tumor-adjacent stroma

Here we tested the hypothesis that SNPs associated with prostate cancer risk, might differentially affect RNA expression in prostate cancer stroma. The most significant 35 SNP loci were selected from Genome Wide Association (GWA) studies of ~40,000 patients. We also selected 4030 transcripts previously associated with prostate cancer diagnosis and prognosis. eQTL analysis was carried out by a modified BAYES method to analyze the associations between the risk variants and expressed transcripts jointly in a single model. We observed 47 significant associations between eight risk variants and the expression patterns of 46 genes. This is the first study to identify associations between multiple SNPs and multiple in trans gene expression differences in cancer stroma. Potentially, a combination of SNPs and associated expression differences in prostate stroma may increase the power of risk assessment for individuals, and for cancer progression.

Incorporating Known Genetic Variants Does Not Improve the Accuracy of PSA Testing to Identify High Risk Prostate Cancer on Biopsy

INTRODUCTION

Prostate-specific antigen (PSA) testing is a widely accepted screening method for prostate cancer, but with low specificity at thresholds giving good sensitivity. Previous research identified four single nucleotide polymorphisms (SNPs) principally associated with circulating PSA levels rather than with prostate cancer risk (TERT rs2736098, FGFR2 rs10788160, TBX3 rs11067228, KLK3 rs17632542). Removing the genetic contribution to PSA levels may improve the ability of the remaining biologically-determined variation in PSA to discriminate between high and low risk of progression within men with identified prostate cancer. We investigate whether incorporating information on the PSA-SNPs improves the discrimination achieved by a single PSA threshold in men with raised PSA levels.

MATERIALS AND METHODS

Men with PSA between 3-10 ng/mL and histologically-confirmed prostate cancer were categorised as high or low risk of progression (Low risk: Gleason score≤6 and stage T1-T2a; High risk: Gleason score 7-10 or stage T2C). We used the combined genetic effect of the four PSA-SNPs to calculate a genetically corrected PSA risk score. We calculated the Area under the Curve (AUC) to determine how well genetically corrected PSA risk scores distinguished men at high risk of progression from low risk men.

RESULTS

The analysis includes 868 men with prostate cancer (Low risk: 684 (78.8%); High risk: 184 (21.2%)). Receiver operating characteristic (ROC) curves indicate that including the 4 PSA-SNPs does not improve the performance of measured PSA as a screening tool for high/low risk prostate cancer (measured PSA level AUC = 59.5% (95% CI: 54.7,64.2) vs additionally including information from the 4 PSA-SNPs AUC = 59.8% (95% CI: 55.2,64.5) (p-value = 0.40)).

CONCLUSION

We demonstrate that genetically correcting PSA for the combined genetic effect of four PSA-SNPs, did not improve discrimination between high and low risk prostate cancer in men with raised PSA levels (3-10 ng/mL). Replication and gaining more accurate estimates of the effects of the 4 PSA-SNPs and additional variants associated with PSA levels and not prostate cancer could be obtained from subsequent GWAS from larger prospective studies.

Association of genetic polymorphisms in the telomerase reverse transcriptase gene with prostate cancer aggressiveness

Telomerase reverse transcriptase (TERT), encoded by the TERT gene, is an essential component of telomerase, essential for the maintenance of telomere DNA length, chromosomal stability and cellular immortality. The aim of the present study was to evaluate the association between common genetic variations across the TERT gene region and prostate cancer (PCa) aggressiveness in a Chinese population. A total of 12 TERT tagging single-nucleotide polymorphisms (SNPs) were genotyped on the Sequenom Mass-ARRAY iPLEX® platform in a case-case study with 1,210 Chinese patients with PCa. Unconditional logistic regression was used to investigate the association of genotypes with PCa aggressiveness, Gleason grade and risk of developing early-onset PCa. It was observed that the C allele of the TERT intron 2 SNP (rs2736100) was significantly associated with reduced risk of PCa aggressiveness [odds ratio (OR)=0.81; 95% confidence interval (CI): 0.66-0.99; P=0.037]. This allele was also significantly correlated with a reduced risk of developing a tumor with a high Gleason score (>7; OR=0.83; 95% CI: 0.70-0.99; P=0.039). The T allele of the intron 4 SNP (rs10069690) was found to be significantly associated with a decreased risk for an aggressive form of PCa (OR=0.76; 95% CI: 0.59-0.97; P=0.030). In addition, the A allele of rs10078761 located at the 3' end of the TERT gene exhibited a statistically significant association with the reduced risk of developing a higher grade disease (OR=0.48; 95% CI: 0.28-0.81; P=0.006). However, no association between TERT polymorphisms and age at diagnosis was observed in the present study. The present findings demonstrated for the first time, to the best of our knowledge, that genetic variations across the TERT gene are associated with PCa aggressiveness in a Chinese Han population.

The genetic epidemiology of prostate cancer and its clinical implications

Worldwide, familial and epidemiological studies have generated considerable evidence of an inherited component to prostate cancer. Indeed, rare highly penetrant genetic mutations have been implicated. Genome-wide association studies (GWAS) have also identified 76 susceptibility loci associated with prostate cancer risk, which occur commonly but are of low penetrance. However, these mutations interact multiplicatively, which can result in substantially increased risk. Currently, approximately 30% of the familial risk is due to such variants. Evaluating the functional aspects of these variants would contribute to our understanding of prostate cancer aetiology and would enable population risk stratification for screening. Furthermore, understanding the genetic risks of prostate cancer might inform predictions of treatment responses and toxicities, with the goal of personalized therapy. However, risk modelling and clinical translational research are needed before we can translate risk profiles generated from these variants into use in the clinical setting for targeted screening and treatment.

HOXB13 mutation and prostate cancer: studies of siblings and aggressive disease

BACKGROUND

Recent work detected for the first time a high-risk prostate cancer mutation, in homeobox B13 (HOXB13) among European-Americans.

METHODS

We further evaluated this G84E missense mutation (rs138213197) in two genetic association studies of prostate cancer: a family-based study of brothers and a case-control study of more aggressive disease (N = 2,665 total). We then calculated overall impact of this mutation by pooling all published studies of European-Americans.

RESULTS

In our studies, the mutation was found exclusively among men with prostate cancer (carrier frequency = 1.48%) or unaffected brothers of cases carrying the mutation (frequency = 0.34%), and carrying the mutation gave an OR for disease = 4.79 (P = 0.01). The G84E mutation was more common among men with an earlier age of onset (≤55 years) or a family history of prostate cancer. We also observed for the first time an African-American case carrying the G84E mutation, although at HOXB13 both of his chromosomes were of European-American ancestry. The pooled analysis also indicated that carrying the G84E mutation results in an almost five-fold increase in risk of prostate cancer (P = 3.5 × 10(-17)), and this risk is even higher among cases with an early age of prostate cancer onset (≤55 years) or a family history of disease: a test of heterogeneity across these strata gives P < 1 × 10(-5).

CONCLUSIONS

The HOXB13 mutation substantially increases risk of early onset, familial prostate cancer in European-American men.

IMPACT

Testing for the G84E mutation in men with a positive family history may help distinguish those who merit more regular screening for prostate cancer.

Association of the innate immunity and inflammation pathway with advanced prostate cancer risk

Prostate cancer is the most frequent and second most lethal cancer in men in the United States. Innate immunity and inflammation may increase the risk of prostate cancer. To determine the role of innate immunity and inflammation in advanced prostate cancer, we investigated the association of 320 single nucleotide polymorphisms, located in 46 genes involved in this pathway, with disease risk using 494 cases with advanced disease and 536 controls from Cleveland, Ohio. Taken together, the whole pathway was associated with advanced prostate cancer risk (P = 0.02). Two sub-pathways (intracellular antiviral molecules and extracellular pattern recognition) and four genes in these sub-pathways (TLR1, TLR6, OAS1, and OAS2) were nominally associated with advanced prostate cancer risk and harbor several SNPs nominally associated with advanced prostate cancer risk. Our results suggest that the innate immunity and inflammation pathway may play a modest role in the etiology of advanced prostate cancer through multiple small effects.

Genetic variants in the integrin gene predicted microRNA-binding sites were associated with the risk of prostate cancer

microRNAs (miRNA) silence target genes through Watson-Crick based binding to the 3'untranslated regions (3'UTR). Thus, polymorphisms in the miRNA-binding sites may disrupt this process and play a potential role in cancer pathogenesis. Integrins have been implicated in the genesis and development of many tumors. This study was designed to evaluate the association between five SNP loci in predicted miRNA-binding sites in five integrin genes and prostate cancer occurrence and prognosis to provide data for screening high-risk Chinese Han individuals. These five polymorphisms were genotyped by using the high-resolution melting method (HRM) in 347 Chinese Han prostate cancer patients with long-time follow-up together with 367 age-matched healthy controls. GC carriers of rs11902171 in ITGAv were associated with a decreased risk of prostate cancer (OR 0.57, 95% CI 0.35-0.93). However, no significant difference was detected in genotype distributions of the five SNP loci in the progression-free survival time of prostate cancer. The ITGAv gene SNP rs11902171 may be potentially associated with the risk of prostate cancer.

Variation in IL10 and other genes involved in the immune response and in oxidation and prostate cancer recurrence

BACKGROUND

To evaluate the association of variation in genes involved in immune response, including IL10, production and detoxification of reactive oxygen species, and repair of oxidative DNA damage with risk of recurrence after surgery for localized prostate cancer.

METHODS

We conducted a nested case-control study of men who had a radical prostatectomy in 1993 to 2001. A total of 484 recurrence cases and 484 controls were matched on age, race, and pathologic stage and grade. Germline DNA was extracted from paraffin-embedded unaffected lymph nodes. We genotyped candidate single-nucleotide polymorphisms (SNP) in IL10, CRP, GPX1, GSR, GSTP1, hOGG1, IL1B, IL1RN, IL6, IL8, MPO, NOS2, NOS3, SOD1, SOD2, SOD3, TLR4, and TNF and tagging SNPs in IL10, CRP, GSR, IL1RN, IL6, NOS2, and NOS3. We used conditional logistic regression to estimate OR and 95% confidence intervals (CI).

RESULTS

The minor allele (A) in IL10 rs1800872, known to produce less interleukin-10 (IL-10), was associated with a higher risk of recurrence (OR = 1.76, 95% CI: 1.00-3.10), and the minor allele (G) in rs1800896, known to produce more IL-10, was associated with a lower risk of recurrence (OR = 0.66, 95% CI: 0.48-0.91). We also observed associations for candidate SNPs in CRP, GSTP1, and IL1B. A common IL10 haplotype and 2 common NOS2 haplotypes were associated with recurrence.

CONCLUSION

Variation in IL10, CRP, GSTP1, IL1B, and NOS2 was associated with prostate cancer recurrence independent of pathologic prognostic factors.

IMPACT

This study supports that genetic variation in immune response and oxidation influence prostate cancer recurrence risk and suggests genetic variation in these pathways may inform prognosis.

Emerging putative biomarkers: the role of alpha 2 and 6 integrins in susceptibility, treatment, and prognosis

The genetic architecture underpinning prostate cancer is complex, polygenic and despite recent significant advances many questions remain. Advances in genetic technologies have greatly improved our ability to identify genetic variants associated with complex disease including prostate cancer. Genome-wide association studies (GWASs) and microarray gene expression studies have identified genetic associations with prostate cancer susceptibility and tumour development. The integrins feature prominently in both studies examining the underlying genetic susceptibility and mechanisms driving prostate tumour development. Integrins are cell adhesion molecules involved in extracellular and intracellular signalling and are imperative for tumour development, migration, and angiogenesis. Although several integrins have been implicated in tumour development, the roles of integrin α(2) and integrin α(6) are the focus of this paper as evidence is now emerging that these integrins are implicit in prostate cancer susceptibility, cancer stem cell biology, angiogenesis, cell migration, and metastases to bone and represent potential biomarkers and therapeutic targets. There currently exists an urgent need to develop tools that differentiate indolent from aggressive prostate cancers and predict how patients will respond to treatment. This paper outlines the evidence supporting the use of α(2) and α(6) integrins in clinical applications for tailored patient treatment.

Genetic variants associated with predisposition to prostate cancer and potential clinical implications

Prostate cancer is the commonest cancer in the developed world. There is an inherited component to this disease as shown in familial and twin studies. However, the discovery of these variants has been difficult. The emergence of genome-wide association studies has led to the identification of over 46 susceptibility loci. Their clinical utility to predict risk, response to treatment, or treatment toxicity, remains undefined. Large consortia are needed to achieve adequate statistical power to answer these genetic-clinical and genetic-epidemiological questions. International collaborations are currently underway to link genetic with clinical/epidemiological data to develop risk prediction models, which could direct screening and treatment programs.

Concordance of tumor differentiation among brothers with prostate cancer

BACKGROUND

Genetic factors seem to be of greater importance in prostate cancer than in other forms of cancer. Studies have suggested familial concordance in survival, but the extent to which that is due to tumor characteristics is not known.

OBJECTIVE

We hypothesized that a brother of an index case with prostate cancer is at particularly increased risk of prostate cancer with the same tumor differentiation as the index case.

DESIGN, SETTING AND PARTICIPANTS

We identified 21,930 brothers of index cases with prostate cancer in the Prostate Cancer Data Base Sweden and followed them up for incidence of prostate cancer.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The relative risk of Gleason score-specific prostate cancer in the cohort of brothers was estimated by using the standardized incidence ratio (SIR) stratified by Gleason score of the index case. We estimated 95% confidence intervals (CIs) assuming a Poisson distribution.

RESULTS AND LIMITATIONS

Among brothers of index cases with Gleason score 8-10 cancer, the SIR was 2.53 (95% CI, 1.97-3.21) for a Gleason score 2-6 cancer and 4.00 (95% CI, 2.63-5.82) for a Gleason score 8-10 cancer. SIR for Gleason score 2-6 cancer among brothers decreased with time since the date of the index cases' diagnoses, whereas the risk of Gleason 8-10 cancer increased over time for brothers of index cases with Gleason 8-10 cancer (p for trend = 0.009).

CONCLUSIONS

Brothers of men with high-grade prostate cancer are at particularly increased risk of high-grade prostate cancer. Likewise, there is a concordance of less malignant prostate cancers within families. These findings may have direct clinical relevance for counseling men with a family history of prostate cancer.

Prostate cancer risk variants are not associated with disease progression

BACKGROUND

Currently used prognostic markers are limited in their ability to accurately predict disease progression among patients with localized prostate cancer. We examined 23 reported prostate cancer susceptibility variants for association with disease progression.

METHODS

Disease progression was explored among 4,673 Swedish patients treated for clinically localized prostate cancer between 1997 and 2002. Prostate cancer progression was defined according to primary treatment as a composed event reflecting termination of deferred treatment, biochemical recurrence, local progression, or presence of distant metastasis. Association between single variants, and all variants combined, were performed in Cox regression analysis assuming both log-additive and co-dominant genetic models.

RESULTS

Three of the 23 genetic variants explored were nominally associated with prostate cancer progression; rs9364554 (P = 0.041) on chromosome 6q25 and rs10896449 (P = 0.029) on chromosome 11q13 among patients treated with curative intent; and rs4054823 (P = 0.008) on chromosome 17p12 among patients on surveillance. However, none of these associations remained statistically significant after correction for multiple testing. The combined effect of all susceptibility variants was not associated with prostate cancer progression neither among patients receiving treatment with curative intent (P = 0.14) nor among patients on surveillance (P = 0.92).

CONCLUSIONS

We observed no evidence for an association between any of 23 established prostate cancer genetic risk variants and disease progression. Accumulating evidence suggests separate genetic components for initiation and progression of prostate cancer. Future studies systematically searching for genetic risk variants associated with prostate cancer progression and prognosis are warranted.

Polymorphisms of integrin, alpha 6 contribute to the development and neurologic symptoms of intracerebral hemorrhage in korean population

OBJECTIVE

The extracellular matrix (ECM) and cell adhesion molecules play crucial roles in angiogenesis, apoptosis, thrombosis, and inflammation, and also contribute to the pathogenesis of stroke. Integrin, alpha 6 (ITGA6) is a member of ECM adhesion receptors. We investigated whether two single nucleotide polymorphisms (SNPs) (rs11895564, Ala380Thr; rs2293649, Asp694Asp) of ITGA6 were associated with the development and clinical phenotypes of intracerebral hemorrhage (ICH) and ischemic stroke (IS).

METHODS

We enrolled 199 stroke (78 ICH and 121 IS) and 291 control subjects. Stroke patients were divided into subgroups according to the scores of the National Institutes of Health Stroke Survey (NIHSS, <6 and ≥6) and Modified Barthel Index (MBI, <60 and ≥60). SNPStats, SNPAnalyzer, and Helixtree programs were used to calculate odds ratios, 95% confidence intervals, and p values. Multiple logistic regression models were used to analyze genetic data.

RESULTS

A missense SNP rs11895564 was associated with the development of ICH (p=0.026 in codominant2, p=0.013 in recessive, p=0.02 in log-additive models; p=0.041 in allele distributions). The A allele frequency of rs11895564 was higher in the ICH group (13.5%) than in the control group (8.1%). In the clinical phenotypes, rs11895564 and rs2293649 showed significant associations in the MBI scores of IS (p=0.014 in codominant1 model; p=0.02 in allele distributions) and NIHSS scores of ICH (p=0.017 in codominant2, p=0.035 in recessive, p=0.035 in log-additive models), respectively.

CONCLUSION

These results suggest that ITGA6 may be associated with the development and clinical phenotypes of stroke in Korean population.

A missense polymorphism (rs11895564, Ala380Thr) of integrin alpha 6 is associated with the development and progression of papillary thyroid carcinoma in Korean population

Purpose

Integrins play crucial roles in the pathogenesis of papillary thyroid carcinoma (PTC). The aim of this study was to investigate whether two single nucleotide polymorphisms (SNPs) (rs2141698, -1687A/G; rs11895564, Ala380Thr) of the integrin alpha 6 (ITGA6) gene are associated with the development and clinicopathologic characteristics of PTC such as the size (<1 cm and ≥1 cm), number (unifocality and multifocality), location (one lobe and both lobes), extrathyroid invasion, and cervical lymph node metastasis.

Methods

We enrolled 104 PTC patients and 318 control subjects. Genotypes of each SNP were determined by direct sequencing. SNPStats, SNPAnalyzer, and Helixtree programs were used to evaluate odds ratios (ORs), 95% confidence intervals (CIs), and P-values. Multiple logistic regression models were performed to analyze genetic data.

Results

A missense SNP rs11895564 was associated with the development of PTC. The A allele frequency of rs11895564 was higher in PTC patients than in controls (13.5% vs. 7.1%; P = 0.005; OR, 2.04; 95% CI, 1.24 to 3.37). In the clinicopathologic characteristics, the A allele frequency of rs11895564 showed difference in the size (19.6% in <1 cm vs. 6.9% in ≥1 cm; P = 0.010; OR, 0.30; 95% CI, 0.12 to 0.75) and number (8.5% in unifocality vs. 20.8% in multifocality; P = 0.015; OR, 2.85; 95% CI, 1.23 to 6.59) of PTC.

Conclusion

These results suggest that the A allele of rs11895564 (Ala380Thr) in ITGA6 may be a risk factor of PTC, and also contribute to the progression of PTC in the Korean population.

Genetic variants in the LEPR, CRY1, RNASEL, IL4, and ARVCF genes are prognostic markers of prostate cancer-specific mortality

BACKGROUND

Prostate cancer is the second leading cause of cancer-related deaths in men, accounting for more than 30,000 deaths annually. The purpose of this study was to test whether variation in selected candidate genes in biological pathways of interest for prostate cancer progression could help distinguish patients at higher risk for fatal prostate cancer.

METHODS

In this hypothesis-driven study, we genotyped 937 single nucleotide polymorphisms (SNPs) in 156 candidate genes in a population-based cohort of 1,309 prostate cancer patients. We identified 22 top-ranking SNPs (P ≤ 0.01, FDR ≤ 0.70) associated with prostate cancer-specific mortality (PCSM). A subsequent validation study was completed in an independent population-based cohort of 2,875 prostate cancer patients.

RESULTS

Five SNPs were validated (P ≤ 0.05) as being significantly associated with PCSM, one each in the LEPR, CRY1, RNASEL, IL4, and ARVCF genes. Compared with patients with 0 to 2 of the at-risk genotypes those with 4 to 5 at-risk genotypes had a 50% (95% CI, 1.2-1.9) higher risk of PCSM and risk increased with the number of at-risk genotypes carried (P(trend) = 0.001), adjusting for clinicopathologic factors known to influence prognosis.

CONCLUSION

Five genetic markers were validated to be associated with lethal prostate cancer.

IMPACT

This is the first population-based study to show that germline genetic variants provide prognostic information for prostate cancer-specific survival. The clinical utility of this five-SNP panel to stratify patients at higher risk for adverse outcomes should be evaluated.

Significant associations of prostate cancer susceptibility variants with survival in patients treated with androgen-deprivation therapy

Androgen-deprivation therapy (ADT) is the most common therapy for advanced prostate cancer, but the prognosis significantly differs among individuals. In this study, we evaluated recently identified 19 prostate cancer susceptibility variants as prognostic predictors for the survival after ADT. A total of 601 prostate cancer patients treated with ADT were enrolled in this study cohort. The prognostic significance of the prostate cancer risk variants on disease progression, prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) after ADT were assessed by Kaplan-Meier analysis and Cox regression model. Two polymorphisms, rs16901979 and rs7931342, were significantly associated with PCSM (p = 0.005 for rs16901979 and p = 0.038 for rs7931342), and rs16901979 was also associated with ACM (p = 0.003) following ADT. Although the effect of rs7931342 was attenuated after controlling for other known clinical prognostic factors, rs16901979 remained a significant predictor for PCSM and ACM after ADT (p = 0.002). Moreover, the addition of the rs16901979 status in current clinical staging system further enhanced the risk prediction on PCSM and ACM particularly for the high-risk patients with distant metastasis (p < 0.017). In conclusion, this is the first study showing that prostate cancer risk variants, such as rs16901979, might improve outcome prediction following ADT, thus allowing identification of high-risk patients who might benefit from appropriate adjuvant therapy.

National Cancer Institute Prostate Cancer Genetics Workshop

Compelling evidence supports a genetic component to prostate cancer susceptibility and aggressiveness. Recent genome-wide association studies have identified more than 30 single-nucleotide polymorphisms associated with prostate cancer susceptibility. It remains unclear, however, whether such genetic variants are associated with disease aggressiveness--one of the most important questions in prostate cancer research today. To help clarify this and substantially expand research in the genetic determinants of prostate cancer aggressiveness, the first National Cancer Institute Prostate Cancer Genetics Workshop assembled researchers to develop plans for a large new research consortium and patient cohort. The workshop reviewed the prior work in this area and addressed the practical issues in planning future studies. With new DNA sequencing technology, the potential application of sequencing information to patient care is emerging. The workshop, therefore, included state-of-the-art presentations by experts on new genotyping technologies, including sequencing and associated bioinformatics issues, which are just beginning to be applied to cancer genetics.

Impact of genotyping on outcome of prostatic biopsies: a multicenter prospective study

Single nucleotide polymorphisms (SNPs) have been associated with prostate cancer (PCa) risk and tumor aggressiveness in retrospective studies. To assess the value of genotyping in a clinical setting, we evaluated the correlation between three genotypes (rs1447295 and rs6983267[8q24] and rs4054823[17p12]) and prostatic biopsy outcome prospectively in a French population of Caucasian men. Five hundred ninety-eight patients with prostatic-specific antigen (PSA) >4 ng/mL or abnormal digital rectal examination (DRE) participated in this prospective, multicenter study. Age, familial history of PCa, body mass index (BMI), data of DRE, International Prostate Symptom Score (I-PSS) score, PSA value and prostatic volume were collected prospectively before prostatic biopsy. Correlation between genotypes and biopsy outcome (positive or negative) and Gleason score (≤6 or >6) were studied by univariate and multivariable analysis. rs1447295 and rs6983267 risk variants were found to be associated with the presence of PCa in univariate analysis. rs6983267 genotype remained significantly linked to a positive biopsy (odds ratio [OR] = 1.66, 95% confidence interval [CI]: 1.06-2.59, P = 0.026) in multivariable analysis, but rs1447295 genotype did not (OR = 1.47, 95% CI: 0.89-2.43, P = 0.13).When biopsy outcome was stratified according to Gleason score, risk variants of rs1447295 were associated with aggressive disease (Gleason score ≥7) in univariate and multivariable analysis (OR = 2.05 95% CI: 1.10-3.79, P = 0.023). rs6983267 GG genotype was not related to aggressiveness. The results did not reach significance concerning rs4054823 for any analysis. This inaugural prospective evaluation thus confirmed potential usefulness of genotyping PCa assessment. Ongoing clinical evaluation of larger panels of SNPs will detail the actual impact of genetic markers on clinical practice.