Identification of an aggressive prostate cancer predisposing variant at 11q13

Novel prostate cancer susceptibility gene SP6 predisposes patients to aggressive disease

Prostate cancer (PrCa) is one of the most common cancers in men, but little is known about factors affecting its clinical outcomes. Genome-wide association studies have identified more than 170 germline susceptibility loci, but most of them are not associated with aggressive disease. We performed a genome-wide analysis of 185,478 SNPs in Finnish samples (2738 cases, 2400 controls) from the international Collaborative Oncological Gene-Environment Study (iCOGS) to find underlying PrCa risk variants. We identified a total of 21 common, low-penetrance susceptibility loci, including 10 novel variants independently associated with PrCa risk. Novel risk loci were located in the 8q24 (CASC8 rs16902147, OR 1.86, p_adj = 3.53 × 10^-8 and rs58809953, OR 1.71, p_adj = 4.00 × 10^-6; intergenic rs79012498, OR 1.81, p_adj = 4.26 × 10^-8), 17q21 (SP6 rs2074187, OR 1.66, p_adj = 3.75 × 10^-5), 11q13 (rs12795301, OR 1.42, p_adj = 2.89 × 10^-5) and 8p21 (rs995432, OR 1.38, p_adj = 3.00 × 10^-11) regions. Here, we describe SP6, a transcription factor gene, as a new, potentially high-risk gene for PrCa. The intronic variant rs2074187 in SP6 was associated not only with overall susceptibility to PrCa (OR 1.66) but also with a higher odds ratio for aggressive PrCa (OR 1.89) and lower odds for non-aggressive PrCa (OR 1.43). Furthermore, the new intergenic variant rs79012498 at 8q24 conferred risk for aggressive PrCa. Our findings highlighted the power of a population-stratified approach to identify novel, clinically actionable germline PrCa risk loci and strongly suggested SP6 as a new PrCa candidate gene that may be involved in the pathogenesis of PrCa.

Synergistic Interaction of HOXB13 and CIP2A Predisposes to Aggressive Prostate Cancer

PURPOSE

Distinguishing aggressive prostate cancer from indolent disease improves personalized treatment. Although only few genetic variants are known to predispose to aggressive prostate cancer, synergistic interactions of HOXB13 G84E high-risk prostate cancer susceptibility mutation with other genetic loci remain unknown. The purpose of this study was to examine the interplay of HOXB13 rs138213197 (G84E) and CIP2A rs2278911 (R229Q) germline variants on prostate cancer risk.

EXPERIMENTAL DESIGN

Genotyping was done in Finnish discovery cohort (n = 2,738) and validated in Swedish (n = 3,132) and independent Finnish (n = 1,155) prostate cancer cohorts. Expression pattern analysis was followed by functional studies in prostate cancer cell models.

RESULTS

Interplay of HOXB13 (G84E) and CIP2A (R229Q) variants results in highest observed inherited prostate cancer risk (OR, 21.1; P = 0.000024). In addition, this synergism indicates a significant association of HOXB13 T and CIP2A T dual carriers with elevated risk for high Gleason score (OR, 2.3; P = 0.025) and worse prostate cancer-specific life expectancy (HR, 3.9; P = 0.048), and it is linked with high PSA at diagnosis (OR, 3.30; P = 0.028). Furthermore, combined high expression of HOXB13-CIP2A correlates with earlier biochemical recurrence. Finally, functional experiments showed that ectopic expression of variants stimulates prostate cancer cell growth and migration. In addition, we observed strong chromatin binding of HOXB13 at CIP2A locus and revealed that HOXB13 functionally promotes CIP2A transcription. The study is limited to retrospective Nordic cohorts.

CONCLUSIONS

Simultaneous presence of HOXB13 T and CIP2A T alleles confers for high prostate cancer risk and aggressiveness of disease, earlier biochemical relapse, and lower disease-specific life expectancy. HOXB13 protein binds to CIP2A gene and functionally promotes CIP2A transcription.

Clinical importance of the EMSY gene expression and polymorphisms in ovarian cancer

EMSY, a BRCA2–associated protein, is amplified and overexpressed in various sporadic cancers. This is the first study assessing the clinical impact of its expression and polymorphisms on ovarian cancer (OvCa) outcome in the context of the chemotherapy regimen used. In 134 frozen OvCa samples, we assessed EMSY mRNA expression with Reverse Transcription-quantitative PCR, and also investigated the EMSY gene sequence using SSCP and/or PCR-sequencing. Clinical relevance of changes in EMSY mRNA expression and DNA sequence was evaluated in two subgroups treated with either taxane/platinum (TP, n=102) or platinum/cyclophosphamide (PC, n=32). High EMSY expression negatively affected overall survival (OS), disease-free survival (DFS) and sensitivity to treatment (PS) in the TP-treated subgroup (p-values: 0.001, 0.002 and 0.010, respectively). Accordingly, our OvCa cell line studies showed that the EMSY gene knockdown sensitized A2780 and IGROV1 cells to paclitaxel. Interestingly, EMSY mRNA expression in surviving cells was similar as in the control cells. Additionally, we identified 24 sequence alterations in the EMSY gene, including the previously undescribed: c.720G>C, p.(Lys240Asn); c.1860G>A, p.(Lys620Lys); c.246-76A>G; c.421+68A>C. In the PC-treated subgroup, a heterozygous genotype comprising five SNPs (rs4300410, rs3814711, rs4245443, rs2508740, rs2513523) negatively correlated with OS (p-value=0.009). The same SNPs exhibited adverse borderline associations with PS in the TP-treated subgroup. This is the first study providing evidence that high EMSY mRNA expression is a negative prognostic and predictive factor in OvCa patients treated with TP, and that the clinical outcome may hinge on certain SNPs in the EMSY gene as well.

Germline EMSY sequence alterations in hereditary breast cancer and ovarian cancer families

BACKGROUND

BRCA1 and BRCA2 mutations explain approximately one-fifth of the inherited susceptibility in high-risk Finnish hereditary breast and ovarian cancer (HBOC) families. EMSY is located in the breast cancer-associated chromosomal region 11q13. The EMSY gene encodes a BRCA2-interacting protein that has been implicated in DNA damage repair and genomic instability. We analysed the role of germline EMSY variation in breast/ovarian cancer predisposition. The present study describes the first EMSY screening in patients with high familial risk for this disease.

METHODS

Index individuals from 71 high-risk, BRCA1/2-negative HBOC families were screened for germline EMSY sequence alterations in protein coding regions and exon-intron boundaries using Sanger sequencing and TaqMan assays. The identified variants were further screened in 36 Finnish HBOC patients and 904 controls. Moreover, one novel intronic deletion was screened in a cohort of 404 breast cancer patients unselected for family history. Haplotype block structure and the association of haplotypes with breast/ovarian cancer were analysed using Haploview. The functionality of the identified variants was predicted using Haploreg, RegulomeDB, Human Splicing Finder, and Pathogenic-or-Not-Pipeline 2.

RESULTS

Altogether, 12 germline EMSY variants were observed. Two alterations were located in the coding region, five alterations were intronic, and five alterations were located in the 3'untranslated region (UTR). Variant frequencies did not significantly differ between cases and controls. The novel variant, c.2709 + 122delT, was detected in 1 out of 107 (0.9%) breast cancer patients, and the carrier showed a bilateral form of the disease. The deletion was absent in 897 controls (OR = 25.28; P = 0.1) and in 404 breast cancer patients unselected for family history. No haplotype was identified to increase the risk of breast/ovarian cancer. Functional analyses suggested that variants, particularly in the 3'UTR, were located within regulatory elements. The novel deletion was predicted to affect splicing regulatory elements.

CONCLUSIONS

These results suggest that the identified EMSY variants are likely neutral at the population level. However, these variants may contribute to breast/ovarian cancer risk in single families. Additional analyses are warranted for rare novel intronic deletions and the 3'UTR variants predicted to have functional roles.

Prostate cancer screening using risk stratification based on a multi-state model of genetic variants

BACKGROUND

Risk-stratified screening for prostate cancer (PCa) with prostate-specific antigen (PSA) testing incorporating genetic variants has received some attention but has been scarcely investigated. We developed a model to stratify the Finnish population by different risk profiles related to genetic variants to optimize the screening policy.

METHODS

Data from the Finnish randomized controlled trial on screening for PCa with PSA testing were used to estimate a six-state Markov model of disease progression. Blood samples from Finnish men were used to assess the risk of PCa related to three genetic variants (rs4242382, rs138213197, and rs200331695). A risk score-based approach combined with a series of computer simulation models was applied to optimize individual screening policies.

RESULTS

The 10-year risk of having progressive prostate cancer detected ranged from 43% in the top 5% risk group to approximately 11% in the bottom half of the population. Using the median group, with screening every four years beginning at 55 years-old, as the reference group, the recommended age beginning screening was approximately 47 years-old for the top 5% risk group and 55 years-old for those in the lower 60% risk group. The recommended interscreening interval has been shortened for individuals in the high risk group. The increased availability of genomic information allows the proposed multistate model to be more discriminating with respect to risk stratification and the suggested screening policy, particularly for the lowest risk groups-. --

CONCLUSIONS

A multi-state genetic variant-based model was developed for further application to population risk stratification to optimize the interscreening interval and the age at which to begin screening for PSA. A small sub-group of the population is likely to benefit from more intensive screening with early start and short interval, while half of the population is unlikely to benefit from such protocol (compared with four-year interval after age 55 years).

Associations of prostate cancer risk variants with disease aggressiveness: results of the NCI-SPORE Genetics Working Group analysis of 18,343 cases

Genetic studies have identified single nucleotide polymorphisms (SNPs) associated with the risk of prostate cancer (PC). It remains unclear whether such genetic variants are associated with disease aggressiveness. The NCI-SPORE Genetics Working Group retrospectively collected clinicopathologic information and genotype data for 36 SNPs which at the time had been validated to be associated with PC risk from 25,674 cases with PC. Cases were grouped according to race, Gleason score (Gleason ≤ 6, 7, ≥ 8) and aggressiveness (non-aggressive, intermediate, and aggressive disease). Statistical analyses were used to compare the frequency of the SNPs between different disease cohorts. After adjusting for multiple testing, only PC-risk SNP rs2735839 (G) was significantly and inversely associated with aggressive (OR = 0.77; 95 % CI 0.69-0.87) and high-grade disease (OR = 0.77; 95 % CI 0.68-0.86) in European men. Similar associations with aggressive (OR = 0.72; 95 % CI 0.58-0.89) and high-grade disease (OR = 0.69; 95 % CI 0.54-0.87) were documented in African-American subjects. The G allele of rs2735839 was associated with disease aggressiveness even at low PSA levels (<4.0 ng/mL) in both European and African-American men. Our results provide further support that a PC-risk SNP rs2735839 near the KLK3 gene on chromosome 19q13 may be associated with aggressive and high-grade PC. Future prospectively designed, case-case GWAS are needed to identify additional SNPs associated with PC aggressiveness.

Expression of EMSY, a novel BRCA2-link protein, is associated with lymph node metastasis and increased tumor size in breast carcinomas

BACKGROUND

The EMSY gene encodes a BRCA2-binding partner protein that represses the DNA repair function of BRCA2 in non-hereditary breast cancer. Although amplification of EMSY gene has been proposed to have prognostic value in breast cancer, no data have been available concerning EMSY tissue expression patterns and its associations with clinicopathological features.

MATERIALS AND METHODS

In the current study, we examined the expression and localization pattern of EMSY protein by immunohistochemistry and assessed its prognostic value in a well-characterized series of 116 unselected breast carcinomas with a mean follow up of 47 months using tissue microarray technique.

RESULTS

Immunohistochemical expression of EMSY protein was detected in 76% of primary breast tumors, localized in nuclear (18%), cytoplasmic (35%) or both cytoplasmic and nuclear sites (23%). Univariate analysis revealed a significant positive association between EMSY expression and lymph node metastasis (p value=0.045) and larger tumor size (p value=0.027), as well as a non-significant relation with increased risk of recurrence (p value=0.088), whereas no association with patients' survival (log rank test, p value=0.482), tumor grade or type was observed.

CONCLUSIONS

Herein, we demonstrated for the first time the immunostaining pattern of EMSY protein in breast tumors. Our data imply that EMSY protein may have impact on clinicipathological parameters and could be considered as a potential target for breast cancer treatment.

The function of EMSY in cancer development

EMSY was first reported to bind BRCA2 and to inactivate the function of BRCA2, leading to the development of sporadic breast and ovarian cancers. The function of EMSY may also be involved in DNA damage repair, genomic instability, and chromatin remolding. Recent studies have shown that amplification of EMSY was also associated with other cancers such as prostate and pancreatic cancers and linked to tumor phenotypes and clinical outcomes. By reviewing literatures published since 2003, here, we have summarized the recent advances of EMSY in cancer development.

Fine mapping of 11q13.5 identifies regions associated with prostate cancer and prostate cancer death

BACKGROUND

Chromosomal region 11q13-14 associates with prostate cancer (PrCa). Previously, we identified a rare intronic mutation on EMSY (11q13.5) that increases the risk of aggressive PrCa and associates with familial PrCa. Here, we further study the genetic structure and variants of the PrCa susceptibility region 11q13.5.

METHODS

This study included 2716 unselected hospital-based PrCa cases, 1318 cases of a screening trial and 908 controls of Finnish origin. We imputed single nucleotide polymorphisms (SNPs) and structural variants from the 1000 Genomes Project and validated the associations of the variants in two PrCa patient sets by genotyping. Genetic structure was studied with haplotype analysis.

RESULTS

Two independent regions at 11q13.5 were associated with PrCa risk. The most significant association was at EMSY (rs10899221, odds ratio (OR) 1.29-1.40, P=3.5 × 10(-4)-0.002) near the previously identified mutation. Correlated intronic SNPs rs10899221 and rs72944758 formed with other EMSY variants common and rare haplotypes that were associated with increased risk (P=4.0 × 10(-4)) and decreased risk (P=0.01) of PrCa, respectively. The other associated region was intergenic. Among the six validated variants, rs12277366 was significant in both patient sets (OR 1.15-1.17, P=0.01). Haplotypes associated with an increased risk (P=0.02) and a decreased risk (P=0.02) were identified. In addition, the intergenic region was strongly associated with PrCa death, with the most significant association at rs12277366 (OR=0.72, P=4.8 × 10(-5)).

CONCLUSIONS

These findings indicate that 11q13.5 contributes to PrCa predisposition with complex genetic structure and is associated with PrCa death.

Genetic sequence variants are associated with severity of lower urinary tract symptoms and prostate cancer susceptibility

PURPOSE

While a clear heritable component underlies lower urinary tract symptoms and benign prostatic hyperplasia, few studies have identified specific genetic factors. In contrast, recent genome-wide association studies identified single nucleotide polymorphisms that increase prostate cancer risk. Some of these single nucleotide polymorphisms may also predispose to surgical intervention for benign prostatic hyperplasia. We determined whether these single nucleotide polymorphisms are also associated with lower urinary tract symptom severity and benign prostatic hyperplasia medication use.

MATERIALS AND METHODS

The genotypes of 38 single nucleotide polymorphisms previously associated with prostate cancer risk were determined for 1,168 healthy white male volunteers. American Urological Association symptom index score and medication for benign prostatic hyperplasia were documented prospectively. Statistical analyses were done to compare the frequency of the single nucleotide polymorphisms with American Urological Association symptom index and benign prostatic hyperplasia medication use.

RESULTS

Several single nucleotide polymorphisms, including rs2736098 on chromosome 5p15, showed a significant relationship with benign prostatic hyperplasia medication. After adjusting for the other genetic variants, patient age and medication use, rs1571801 on chromosome 9q33.2 (OR 1.31, 95% CI 1.0-1.74) and rs5945572 on chromosome Xp11 (OR 1.28, 95% CI 1.04-1.59) were significantly associated with increased urinary symptoms. In contrast, rs445114 on chromosome 8q24 was marginally associated with decreased urinary symptoms (OR 0.83, 95% CI 0.66-1.01).

CONCLUSIONS

Of 38 single nucleotide polymorphisms that predispose to prostate cancer we identified 3 that are also associated with a well characterized lower urinary tract symptom phenotype. These single nucleotide polymorphisms may aid in the improved characterization of men with lower urinary tract symptoms/benign prostatic hyperplasia.