CYP19A1 genetic variation in relation to prostate cancer risk and circulating sex hormone concentrations in men from the Breast and Prostate Cancer Cohort Consortium

A Positive Feedback Loop Exists between Estradiol and IL-6 and Contributes to Dermal Fibrosis

Systemic sclerosis (SSc) is characterized by dermal fibrosis with a female predominance, suggesting a hormonal influence. Patients with SSc have elevated interleukin (IL)-6 levels, and post-menopausal women and older men also have high estradiol (E2) levels. In the skin, IL-6 increases the enzymatic activity of aromatase, thereby amplifying the conversion of testosterone to E2. Therefore, we hypothesized that an interplay between E2 and IL-6 contributes to dermal fibrosis. We used primary dermal fibroblasts from healthy donors and patients with diffuse cutaneous (dc)SSc, and healthy donor skin tissues stimulated with recombinant IL-6 and its soluble receptor (sIL-6R) or E2. Primary human dermal fibroblasts and tissues from healthy donors stimulated with IL-6+sIL-6R produced E2, while E2-stimulated dermal tissues and fibroblasts produced IL-6. Primary dermal fibroblasts from healthy donors treated with IL-6+sIL-6R and the aromatase inhibitor anastrozole (ANA) and dcSSc fibroblasts treated with ANA produced less fibronectin (FN), type III collagen A1 (Col IIIA1), and type V collagen A1 (Col VA1). Finally, dcSSc dermal fibroblasts treated with the estrogen receptor inhibitor fulvestrant also generated less FN, Col IIIA1, and Col VA1. Our data show that IL-6 exerts its pro-fibrotic influence in human skin in part through E2 and establish a positive feedback loop between E2 and IL-6.

Gonadal efficacy of Thymus quinquecostatus Celakovski: Regulation of testosterone levels in aging mouse models

Late-onset hypogonadism (LOH) is an age-related disease in men characterized by decreased testosterone levels with symptoms such as decreased libido, erectile dysfunction, and depression. Thymus quinquecostatus Celakovski (TQC) is a plant used as a volatile oil in traditional medicine, and its bioactive compounds have anti-inflammatory potential. Based on this knowledge, the present study aimed to investigate the effects of TQC extract (TE) on LOH in TM3 Leydig cells and in an in vivo aging mouse model. The aqueous extract of T. quinquecostatus Celakovski (12.5, 25, and 50 µg/mL concentrations) was used to measure parameters such as cell viability, testosterone level, body weight, and gene expression, via in vivo studies. Interestingly, TE increased testosterone levels in TM3 cells in a dose-dependent manner without affecting cell viability. Furthermore, TE significantly increased the expression of genes involved in the cytochrome P450 family (Cyp11a1, Cyp17a1, Cyp19a1, and Srd5a2), which regulate testosterone biosynthesis. In aging mouse models, TE increased testosterone levels without affecting body weight and testicular tissue weight tissue of an aging animal group. In addition, the high-dose TE-treated group (50 mg/kg) showed significantly increased expression of the cytochrome p450 enzymes, similar to the in vitro results. Furthermore, HPLC-MS analysis confirmed the presence of caffeic acid and rosmarinic acid as bioactive compounds in TE. Thus, the results obtained in the present study confirmed that TQC and its bioactive compounds can be used for LOH treatment to enhance testosterone production.

Hormonal and genotoxic estrogen-androgen carcinogenesis in the NBL rat prostate: A role for aromatase

BACKGROUND

Androgens are generally thought to cause prostate cancer, but the data from animal studies suggest that they must be aromatized to estrogen and act in concert with genotoxic estrogen metabolites. The objective of this study was to determine whether treatment with testosterone (T) combined with a nonestrogenic estrogen metabolite and a nongenotoxic estrogenic compound would all be necessary and sufficient for the induction of a high incidence of prostate cancer in the susceptible NBL rat strain.

METHODS

NBL rats were treated with low-dose testosterone via slow-release Silastic implants and with the marginally estrogenic genotoxic catechol estrogen 4-hydroxyestradiol (4OH-E2) and the nongenotoxic estrogen 2-fluoroestradiol (2F-E2) and in one experiment the aromatase inhibitor letrozole via custom-made slow-release pellets. Animals were euthanized 52 weeks after implantation and their pituitaries and prostate complexes weighed and fixed in formalin. Hematoxylin and eosin (H&E)-stained step sections were prepared and examined microscopically for proliferative lesions.

RESULTS

Animals treated with 2F-E2, with or without the other compounds, had enlarged pituitaries demonstrating its estrogenicity. Animals treated with T, with or without the other compounds, had enlarged prostates consistent with its androgenicity. Rats treated with T plus 2F-E2 and 4OH-E2 developed a high incidence of prostatic cancer (89%), while, surprisingly, rats treated with T plus only 2F-E2 also had a high incidence of prostate cancer (95%) contradicting our initial hypothesis. To test whether the formation of E2 from T by aromatase could lead to estrogen genotoxicity and prostate carcinogenesis we then rats treated with T and 2F-E2 also with letrozole and found that it reduced prostate cancer incidence by about 50%.

CONCLUSIONS

These findings indicate that long-term treatment with a nongenotoxic estrogen (2F-E2) and T as well as uninhibited prostatic aromatase activity generating genotoxic E2 are all required for induction of a high incidence of prostatic adenocarcinomas in NBL rats. These and previous data indicate that androgen receptor-mediated action, estrogen receptor mediation, and estrogen genotoxicity are all required and sufficient for hormonal carcinogenesis in the NBL rat prostate. Interference with the estrogen genotoxicity is a potential approach to prostate cancer chemoprevention.

Association of CYP19A1 Gene, Plasma Zinc, and Urinary Zinc with the Risk of Type 2 Diabetes Mellitus in a Chinese Population

To explore the effects of CYP19A1 gene polymorphisms, plasma zinc, and urinary zinc levels and their interactions on type 2 diabetes mellitus (T2DM) in residents of Gongcheng County, Guangxi, China. The case-control study was used for the investing. The MassARRAY System was applied to genotype the CYP19A1 genes rs752760, rs10046, rs10459592, and rs700518 in 540 study subjects. Plasma and urinary zinc concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS). Conditional logistic regression showed that rs752760 and plasma zinc were associated with T2DM risks with ORs of 0.593 (95% CI: 0.371-0.948) and 0.563 (95% CI: 0.356-0.889), respectively. Unconditional logistic regression analysis showed an association between urinary zinc levels and the risk of T2DM as well, with an OR of 0.352 (95% CI: 0.212-0.585). The results of the multiplicative interaction model showed that the rs752760 T allele was associated with a significantly reduced risk of T2DM with moderate/low plasma zinc levels, with ORs of 0.340 (95% CI: 0.161-0.715) and 0.583 (95% CI: 0.346-0.981), respectively, and the rs752760 T allele was also associated with a significantly decreased risk of T2DM with moderate/low urinary zinc levels, with ORs of 0.358 (95% CI: 0.201-0.635) and 0.321 (95% CI: 0.183-0.562), respectively. CYP19A1 rs752760 T allele and moderate/low plasma/urinary zinc levels reduce the risk of T2DM.

Regulatory genes in the androgen production, uptake and conversion (APUC) pathway in advanced prostate cancer

The androgen receptor (AR) signaling pathway regulates the progression of prostate cancer (PC). Metastatic castration-resistant prostate cancer (mCRPC) patients generally receive AR-targeted therapies (ART) or androgen-deprivation therapies (ADT) with the initial response; however, resistance is inevitably observed. Prior studies have shown activity and upregulation of a family of androgen production, uptake, and conversion - APUC genes - based on genomic analyses of patient germlines. Genetic variants of some APUC genes, such as the conversion gene, HSD3B1, predict response to second-generation androgen-targeted therapies. Studies have begun to elucidate the overall role of APUC genes, each with unique actionable enzymatic activity, in mCRPC patient outcomes. The current role and knowledge of the genetic and genomic features of APUC genes in advanced prostate cancer and beyond are discussed in this review. These studies inform of how interpreting behavior of APUC genes through genomic tools will impact the treatment of advanced prostate cancer.

The CYP19A1 (TTTA)n Repeat Polymorphism May Affect the Prostate Cancer Risk: Evidence from a Meta-Analysis

Abnormal aromatase (CYP19A1) expression may participate in prostate cancer (PCa) carcinogenesis. However, the results of studies on the CYP19A1 gene polymorphisms and PCa are conflicting. This meta-analysis aimed to systematically evaluate the associations between the CYP19A1 Arg264Cys polymorphism and the (TTTA)n repeat polymorphism and PCa. Electronic databases (PubMed, EmBase, ScienceDirect, and Cochrane Library) were comprehensively searched to identify eligible studies. The strength of the association between the Arg264Cys polymorphism and PCa was assessed by pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) in allelic, dominant, recessive, homozygous, and heterozygous genetic models. To analyze the impact of the (TTTA)n repeat polymorphism, we sequentially took the N-repeat allele (where N equals 7,8,10,11,12, and 13) as the minor allele and the sum of all the other alleles as the major allele. The ORs and 95% CIs were calculated in the allelic model; this analysis was performed individually for each repeat number. Pooled estimates of nine studies addressing the Arg264Cys polymorphism indicated that this polymorphism was not associated with PCa risk in the overall population or in the Caucasian or Asian subgroups. The 8-repeat allele in the (TTTA)n repeat polymorphism increased PCa risk in the overall population (OR = 1.34, 95% CI = 1.14-1.58, p = .001) and in the subgroup with population-based (PB) controls (OR = 1.41, 95% CI = 1.13-1.74, p = .002) as well as in the subgroup using capillary electrophoresis to identify this polymorphism (OR = 1.34, 95% CI = 1.09-1.65, p = .006).The meta-analysis indicated that the CYP19A1 (TTTA)n repeat polymorphism, but not the Arg264Cys polymorphism, may affect PCa risk.

The Associations of Androgen-Related Genes CYP21A2 and CYP19A1 with Severe Acne Vulgaris in Patients from Southwest China

Objective

Androgens acting through the androgen receptor play a crucial role in the pathogenesis of acne. This study aimed to identify whether two key genes (CYP21A2 and CYP19A1) involved in the synthesis and metabolism of androgens were associated with Pillsbury III-IV severe acne vulgaris.

Methods

We carried out a standard questionnaire survey about acne and enlisted 600 Pillsbury III-IV severe acne vulgaris patients and 652 healthy controls of Han Chinese descent from Yunnan, China in the study. Twenty-two single nucleotide polymorphisms (SNPs) were genotyped by SNaPshot assay and analyzed for association with severe acne.

Results

There was no significant difference in gender between the two groups (P = 0.085), and the age of the acne case group was significantly lower than that of the control group (P < 0.001). Our results revealed that only two SNPs, rs6474 (p.Arg102Lys) (P = 0.001) and rs6465 (P = 0.025) of the CYP21A2 gene were significantly associated with severe acne among the Han Chinese. When subjects were divided into males and females, significant associations were observed only in male patients with severe acne vulgaris for four variants: CYP21A2 rs6474 (p.Arg102Lys) (P = 0.002); CYP21A2 rs6465 (P = 0.012); CYP19A1 rs8023263 (P = 0.037); and CYP19A1 rs2470152 (P = 0.007). Haplotype analyses showed that the distribution of CYP21A2 haplotypes was significantly associated with male patients, while no association of CYP19A1 haplotypes was observed. The structure of the human CYP21A2 consists of two substrate binding sites and one substrate access channel.

Conclusion

This study shed a light on a potentially important effect of CYP21A2 and CYP19A1 genes in severe acne vulgaris in the Han Chinese, especially for male patients. Future studies using independently verified datasets from a broader geographical spectrum will be valuable in identifying the causal and functional variants responsible for severe acne vulgaris within the CYP19A1 and CYP21A2 genes.

Role of Estrogen in Androgen-Induced Prostate Carcinogenesis in NBL Rats

Androgens are thought to cause prostate cancer, but the underlying mechanisms are unclear. Data from animal studies suggest that for androgens to cause prostate cancer, they must be aromatized to estrogen and act in concert with estrogen metabolites. We tested the hypothesis that androgen-receptor and estrogen receptor-mediated effects of androgen and estrogen are necessary, as well as genotoxicity of estrogen metabolites. NBL rats were treated with androgenic and estrogenic compounds for 16-75 weeks through slow-release silastic implants or pellets. Testosterone alone induced cancer in the prostate of 37% of rats. 5α-Dihydrotestosterone, which cannot be converted to estradiol or testosterone, did not cause a significant prostate cancer incidence (4%). Addition of estradiol to 5α-dihydrotestosterone treatment did not markedly enhance prostate cancer incidence (14%), unlike adding estradiol to testosterone treatment which induced a 100% tumor incidence. Testosterone plus estradiol treatment induced a DNA adduct detectable by ³²P-postlabeling, oxidative DNA damage (8-hydroxyguanosine), and lipid peroxidation at the site within the prostate where this treatment causes cancers, preceding later cancer formation. The non-estrogenic 4-hydroxy metabolite of estradiol, when combined with testosterone, induced prostatic dysplasia within 16 weeks and, after long-term treatment, a very low incidence of prostate cancer (21%). When an estrogen that cannot be hydroxylated (2-fluoroestradiol) was added to this combined treatment with testosterone and 4-hydroxyestradiol, dysplasia frequency after 16 weeks was doubled. These results strongly support the hypothesis, but additional definitive studies are needed which may identify new targets to interfere with these mechanisms that are clinically feasible in humans.

The impact of genetic polymorphism on CYP19A1 in androgen-deprivation therapy among Japanese men

PURPOSE

Inadequate suppression of testosterone during androgen-deprivation therapy impairs its efficacy. This study investigated the significance of genetic polymorphism in CYP19A1, which encodes aromatase that catalyzes androgens into estrogens, among men treated with primary ADT for metastatic prostate cancer.

METHODS

This study included 80 Japanese patients with metastatic prostate cancer whose serum testosterone levels during ADT were available. The association of CYP19A1 gene polymorphism (rs1870050) with clinicopathological parameters including serum testosterone levels during ADT as well as progression-free survival and overall survival was examined.

RESULTS

Serum testosterone levels during ADT of men carrying homozygous wild-type (AA) in the CYP19A1 gene [median (interquartile range); 11.6 (8.3-20.3) ng/dl] were higher than those in men carrying the heterozygous/homozygous variant (AC/CC) [median (interquartile range); 10.0 (6.4-12.8) ng/dl]. When adjusted by Gleason score, initial PSA, M-stage and serum testosterone level during ADT, heterozygous/homozygous variant (AC/CC) in the CYP19A1 gene was associated with a lower risk of progression to castration resistance [hazard ratio (95% confidence interval), 0.53 [0.29-0.92], p = 0.025], but not to any-cause death [hazard ratio (95% confidence interval), 0.74 [0.36-1.49], p = 0.40].

CONCLUSIONS

These findings suggest that genetic variation in CYP19A1 (rs1870050) might affect the prognosis of patients with metastatic prostate cancer when treated with ADT by regulating serum testosterone levels.

The role of DENND1A and CYP19A1 gene variants in individual susceptibility to obesity in Turkish population-a preliminary study

Single nucleotide polymorphisms (SNPs), the most common genetic variations in human genome, can manage the predisposition of certain complex diseases or situations such as obesity. Genetic polymorphisms also play an important role as they can impact a population's susceptibility to being overweight or obese and developing related chronic complications such as hypertension, coronary heart disease, diabetes and cancer. The present study comprised of 193 unrelated healthy volunteers (120 females and 73 males) with Turkish origin. Only female adolescents (n = 110) were divided into 2 categories according to their BMI values as overweight (BMI ≥ 25) and normal (18.5 < BMI < 25) according to WHO classification. Genomic DNA was isolated from venous blood samples and genotyping of DENND1A rs10818854 and CYP19A1 rs2414096 variants was performed on Roche Light Cycler 2.0 Real-Time PCR platform. Serum hormone levels were analyzed by Electrochemiluminescent Immunoassay (ECLIA; Roche diagnostics). The genotype distributions were consistent with the Hardy-Weinberg equilibrium for both SNPs in the studied population (p > 0.05). The genotype distribution of DENND1A rs10818854 was determined for the first time in Turkish population and the variant allele frequency was found as 0.095. According to reduced sex hormone-binding globulin levels and increased free androgen index in the present study, obesity was linked with hyperandrogenism in female subjects. Both polymorphisms were investigated as potential genetic susceptibility markers for obesity and neither DENND1A nor CYP19A1 showed any associations.

Sex steroids in the tumor microenvironment and prostate cancer progression

Prostate cancer is uniquely dependent on androgens. Despite years of research on the relationship between androgens and prostate cancer, many questions remain as to the biological effects of androgens and other sex steroids during prostate cancer progression. This article reviews the clinical and basic research on the influence of sex steroids such as androgens, estrogens and progesterone within the prostate tumor microenvironment on the progression of prostate cancer. We review clinical studies to date evaluating serum sex steroids as prognostic biomarkers and discuss their respective biological effects within the prostate tumor microenvironment. We also review the link between genomic alterations and sex steroid levels within prostate tumors. Finally, we highlight the links between sex steroid levels and the function of the immune system within the tumor microenvironment. As the context of treatment of lethal prostate cancer evolves over time, an understanding of this underlying biology remains central to developing optimal treatment approaches.

Genetic Determinants of Circulating Estrogen Levels and Evidence of a Causal Effect of Estradiol on Bone Density in Men

Context

Serum estradiol (E2) and estrone (E1) levels exhibit substantial heritability.

Objective

To investigate the genetic regulation of serum E2 and E1 in men.

Design, Setting, and Participants

Genome-wide association study in 11,097 men of European origin from nine epidemiological cohorts.

Main Outcome Measures

Genetic determinants of serum E2 and E1 levels.

Results

Variants in/near CYP19A1 demonstrated the strongest evidence for association with E2, resolving to three independent signals. Two additional independent signals were found on the X chromosome; FAMily with sequence similarity 9, member B (FAM9B), rs5934505 (P = 3.4 × 10-8) and Xq27.3, rs5951794 (P = 3.1 × 10-10). E1 signals were found in CYP19A1 (rs2899472, P = 5.5 × 10-23), in Tripartite motif containing 4 (TRIM4; rs17277546, P = 5.8 × 10-14), and CYP11B1/B2 (rs10093796, P = 1.2 × 10-8). E2 signals in CYP19A1 and FAM9B were associated with bone mineral density (BMD). Mendelian randomization analysis suggested a causal effect of serum E2 on BMD in men. A 1 pg/mL genetically increased E2 was associated with a 0.048 standard deviation increase in lumbar spine BMD (P = 2.8 × 10-12). In men and women combined, CYP19A1 alleles associated with higher E2 levels were associated with lower degrees of insulin resistance.

Conclusions

Our findings confirm that CYP19A1 is an important genetic regulator of E2 and E1 levels and strengthen the causal importance of E2 for bone health in men. We also report two independent loci on the X-chromosome for E2, and one locus each in TRIM4 and CYP11B1/B2, for E1.

Molecular basis for prostate cancer racial disparities

Prostate cancer (PCa) remains the most common cancer in American men. African-American (AA) men continue to have higher PCa prevalence and mortality rates compared to men in other populations. In addition to socioeconomic factors and lifestyle differences, molecular alterations contribute to this discrepancy. We summarize molecular genetics research results interrelated with the biology of PCa racial disparity. Androgen and androgen receptor (AR) pathways have long been associated with prostate growth. Racial differences have also been found among variants of genes of the enzymes involved in androgen biosynthesis and metabolism. Growth factors and their receptors are a potential cause of the disparity in PCa. Recent molecular and biotechnological approaches in the field of proteomics and genomics will greatly aid the advancement of translational research on racial disparity in PCa, which may help, in finding new prognostic markers and novel therapeutic approaches for the treatment of PCa in AA.

Estrogen receptors α and β and aromatase as independent predictors for prostate cancer outcome

Androgens are considered important in normal prostate physiology and prostate cancer (PCa) pathogenesis. However, androgen-targeted treatment preventing PCa recurrence is still lacking. This indicates additional mediators contributing to cancer development. We sought to determine the prognostic significance of estrogen receptors, ERα and -β, and the aromatase enzyme in PCa. Tissue microarrays were created from 535 PCa patients treated with radical prostatectomy. Expression of ERα, ERβ and aromatase were evaluated using immunohistochemistry. Representative tumor epithelial (TE) and tumor stromal (TS) areas were investigated separately. Survival analyses were used to evaluate the markers correlation to PCa outcome. In univariate analyses, ERα in TS was associated with delayed time to clinical failure (CF) (p = 0.042) and PCa death (p = 0.019), while ERβ was associated with reduced time to biochemical failure (BF) (p = 0.002). Aromatase in TS and TE was associated with increased time to BF and CF respectively (p = 0.016, p = 0.046). Multivariate analyses supported these observations, indicating an independent prognostic impact of all markers. When stratifying the analysis according to different surgical centers the results were unchanged. In conclusion, significant prognostic roles of ERα, ERβ and aromatase were discovered in the in PCa specimens of our large multicenter cohort.

Association of androgen metabolism gene polymorphisms with prostate cancer risk and androgen concentrations: Results from the Prostate Cancer Prevention Trial

BACKGROUND

Prostate cancer is highly influenced by androgens and genes. The authors investigated whether genetic polymorphisms along the androgen biosynthesis and metabolism pathways are associated with androgen concentrations or with the risk of prostate cancer or high-grade disease from finasteride treatment.

METHODS

A nested case-control study from the Prostate Cancer Prevention Trial using data from men who had biopsy-proven prostate cancer (cases) and a group of biopsy-negative, frequency-matched controls was conducted to investigate the association of 51 single nucleotide polymorphisms (SNPs) in 12 genes of the androgen pathway with overall (total), low-grade, and high-grade prostate cancer incidence and serum hormone concentrations.

RESULTS

There were significant associations of genetic polymorphisms in steroid 5α-reductase 1 (SRD5A1) (reference SNPs: rs3736316, rs3822430, rs1560149, rs248797, and rs472402) and SRD5A2 (rs2300700) with the risk of high-grade prostate cancer in the placebo arm of the Prostate Cancer Prevention Trial; 2 SNPs were significantly associated with an increased risk (SRD5A1 rs472402 [odds ratio, 1.70; 95% confidence interval, 1.05-2.75; Ptrend = .03] and SRD5A2 rs2300700 [odds ratio, 1.94; 95% confidence interval, 1.19-3.18; Ptrend = .01]). Eleven SNPs in SRD5A1, SRD5A2, cytochrome P450 family 1, subfamily B, polypeptide 1 (CYP1B1), and CYP3A4 were associated with modifying the mean concentrations of serum androgen and sex hormone-binding globulin; and 2 SNPs (SRD5A1 rs824811 and CYP1B1 rs10012; Ptrend < .05) consistently and significantly altered all androgen concentrations. Several SNPs (SRD5A1 rs3822430, SRD5A2 rs2300700, CYP3A43 rs800672, and CYP19 rs700519; Ptrend < .05) were significantly associated with both circulating hormone levels and prostate cancer risk.

CONCLUSIONS

Germline genetic variations of androgen-related pathway genes are associated with serum androgen concentrations and the risk of prostate cancer. Further studies to examine the functional consequence of novel causal variants are warranted. Cancer 2016;122:2332-2340. © 2016 American Cancer Society.

Polymorphisms in androgen metabolism genes AR, CYP1B1, CYP19, and SRD5A2and prostate cancer risk and aggressiveness in Bulgarian patients

BACKGROUND/AIM

The aim of our study was to elucidate the role of polymorphisms in AR, CYP1B1, CYP19, and SRD5A2 genes for prostate cancer (PC) development in Bulgarian patients.

MATERIALS AND METHODS

We genotyped 246 PC patients and 261 controls (155 with benign prostate hyperplasia and 107 healthy population controls) using direct sequencing, PCR-RFLP, SSCP, and fragment analysis.

RESULTS

The allele and genotype frequencies of most of the studied variants did not differ significantly between cases and controls. Increased frequencies of the C/C genotype and C allele of rs1056837 in CYP1B1, and genotype 7/8 of the (TTTA)n repeat polymorphism in CYP19, were observed in patients in comparison with controls.The 8/9 and the 7/12 genotypes of (TTTA)n in CYP19 showed suggestive evidence for association with decreased prostate cancer risk and the risk for aggressive disease, respectively. The haplotype analysis revealed 2 CYP1B1 haplotypes associated with PC risk reduction.

CONCLUSION

Some CYP1B1 haplotypes and genotypes of the CYP19 (TTTA)n repeat appeared to be associated with disease risk or aggressiveness in Bulgarian PC patients. In contrast, the SRD5A2 polymorphisms (V89L and (TA)n repeat), the CAG repeat in AR, and the Arg264Cys variant in CYP19A1 are most likely not implicated in prostate carcinogenesis.

CYP19A1 fine-mapping and Mendelian randomization: estradiol is causal for endometrial cancer

Candidate gene studies have reported CYP19A1 variants to be associated with endometrial cancer and with estradiol (E2) concentrations. We analyzed 2937 single nucleotide polymorphisms (SNPs) in 6608 endometrial cancer cases and 37 925 controls and report the first genome wide-significant association between endometrial cancer and a CYP19A1 SNP (rs727479 in intron 2, P=4.8×10(-11)). SNP rs727479 was also among those most strongly associated with circulating E2 concentrations in 2767 post-menopausal controls (P=7.4×10(-8)). The observed endometrial cancer odds ratio per rs727479 A-allele (1.15, CI=1.11-1.21) is compatible with that predicted by the observed effect on E2 concentrations (1.09, CI=1.03-1.21), consistent with the hypothesis that endometrial cancer risk is driven by E2. From 28 candidate-causal SNPs, 12 co-located with three putative gene-regulatory elements and their risk alleles associated with higher CYP19A1 expression in bioinformatical analyses. For both phenotypes, the associations with rs727479 were stronger among women with a higher BMI (Pinteraction=0.034 and 0.066 respectively), suggesting a biologically plausible gene-environment interaction.

Polymorphisms in CYP19A1, HSD17B1 and HSD17B2 genes and serum sex hormone level among postmenopausal Japanese women

OBJECTIVE

Extraovarian sex hormone production plays an important role in estrogen biosynthesis in postmenopausal women. We examined possible associations between serum sex hormone level and polymorphisms in CYP19A1, HSD17B1, and HSD17B2. We also assessed possible interaction between these polymorphisms and current overweight.

METHODS

We conducted a cross-sectional study. 785 Japanese natural postmenopausal women were randomly selected from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study database. Information on lifestyle factors was obtained from a self-administered questionnaire. Serum estrogens and androgens levels were measured by liquid chromatography-tandem mass spectrometry. Four tag SNPs (single nucleotide polymorphisms) of CYP19A1, one missense SNP of HSD17B1 and three tag SNPs of HSD17B2 were examined by Invader assay. A trend test was conducted using linear regression.

RESULTS

After adjustment for multiple comparisons, we found that rs4441215 and rs936306 in CYP19A1 and rs4888202 and rs2955160 in HSD17B2 were associated with differences in serum estrone level. Further, rs4441215 and rs936306 were associated with differences in serum estradiol level. None of these polymorphisms showed a significant interaction with current body mass index (BMI).

CONCLUSIONS

Our findings suggested that CYP19A1 and HSD17B2 polymorphisms might be associated with circulating sex hormone levels in Japanese postmenopausal women, independent of current BMI.

Precision Medicine and Men's Health

Precision medicine can greatly benefit men's health by helping to prevent, diagnose, and treat prostate cancer, benign prostatic hyperplasia, infertility, hypogonadism, and erectile dysfunction. For example, precision medicine can facilitate the selection of men at high risk for prostate cancer for targeted prostate-specific antigen screening and chemoprevention administration, as well as assist in identifying men who are resistant to medical therapy for prostatic hyperplasia, who may instead require surgery. Precision medicine-trained clinicians can also let couples know whether their specific cause of infertility should be bypassed by sperm extraction and in vitro fertilization to prevent abnormalities in their offspring. Though precision medicine's role in the management of hypogonadism has yet to be defined, it could be used to identify biomarkers associated with individual patients' responses to treatment so that appropriate therapy can be prescribed. Last, precision medicine can improve erectile dysfunction treatment by identifying genetic polymorphisms that regulate response to medical therapies and by aiding in the selection of patients for further cardiovascular disease screening.

Genotypic and allelic variability in CYP19A1 among populations of African and European ancestry

CYP19A1 facilitates the bioconversion of estrogens from androgens. CYP19A1 intron single nucleotide polymorphisms (SNPs) may alter mRNA splicing, resulting in altered CYP19A1 activity, and potentially influencing disease susceptibility. Genetic studies of CYP19A1 SNPs have been well documented in populations of European ancestry; however, studies in populations of African ancestry are limited. In the present study, ten 'candidate' intronic SNPs in CYP19A1 from 125 African Americans (AA) and 277 European Americans (EA) were genotyped and their frequencies compared. Allele frequencies were also compared with HapMap and ASW 1000 Genomes populations. We observed significant differences in the minor allele frequencies between AA and EA in six of the ten SNPs including rs10459592 (p<0.0001), rs12908960 (p<0.0001), rs1902584 (p = 0.016), rs2470144 (p<0.0001), rs1961177 (p<0.0001), and rs6493497 (p = 0.003). While there were no significant differences in allele frequencies between EA and CEU in the HapMap population, a 1.2- to 19-fold difference in allele frequency for rs10459592 (p = 0.004), rs12908960 (p = 0.0006), rs1902584 (p<0.0001), rs2470144 (p = 0.0006), rs1961177 (p<0.0001), and rs6493497 (p = 0.0092) was observed between AA and the Yoruba (YRI) population. Linkage disequilibrium (LD) blocks and haplotype clusters that is unique to the EA population but not AA was also observed. In summary, we demonstrate that differences in the allele frequencies of CYP19A1 intron SNPs are not consistent between populations of African and European ancestry. Thus, investigations into whether CYP19A1 intron SNPs contribute to variations in cancer incidence, outcomes and pharmacological response seen in populations of different ancestry may prove beneficial.

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 variants in estrogen-related pathway genes with prostate cancer risk

BACKGROUND

Through mediation of estrogen receptors, estradiol has been shown to have both carcinogenic and anti-carcinogenic effects on the prostate. We performed a population-based case-control study to investigate variants in estrogen-related genes ESR1, ESR2, CYP19A1, CYP1A1, and CYP1B1 and the potential association with risk of prostate cancer (PCa).

MATERIALS AND METHODS

We evaluated PCa risk conferred by 73 single nucleotide polymorphisms in 1,304 incident PCa cases and 1,266 age-matched controls. Analysis included stratification by clinical features and assessment of environmental modifiers.

RESULTS

There was evidence of altered risk of developing PCa for variants in ESR1, CYP1A1, and CYP1B1, however, only CYP1B1 rs1056836 retained significance after adjustment for multiple comparisons. An association with risk for more aggressive PCa was observed for variants in ESR1, ESR2, and CYP19A1, but none was significant after adjustment for multiple comparisons. There was no effect modification by obesity.

CONCLUSIONS

Germline genetic variation of these estrogen pathway genes may contribute to risk of PCa. Additional studies to validate these results and examine the functional consequence of validated variants are warranted.

Polymorphisms in androgen signaling pathway predisposing to prostate cancer

Prostate cancer is the most frequent male malignancy diagnosed in western countries and androgens are known to mediate key physiological processes in prostate tissue. Since endogenous androgens have long been considered to be risk factors for prostate cancer, genes involved in androgen biosynthesis and metabolism have been extensively studied. In this review, association of androgen pathway genes, their polymorphic sites and risk of prostate cancer in different ethnic backgrounds is addressed together with their use to predict susceptibility and clinical outcomes of prostate cancer patients. The effect of the polymorphisms seems vary in different patients, populations and ethnic backgrounds. To date it is evident that the association between androgen pathway gene polymorphisms and prostate cancer risk is complex and many of the results are characterized by irreproducibility, which can be attributed to a variety of biological, statistical and technical reasons. In the future, with increasing knowledge, developing technologies and new genomic biomarkers it likely becomes possible to better estimate the risk of prostate cancer, and distinguish indolent disease from aggressive based on molecular profiling, and the analysis of gene-gene and gene-environment interactions.

A perspective on the role of estrogen in hormone-induced prostate carcinogenesis

Androgens are thought to cause prostate cancer, but the precise mechanisms by which they do so are unclear. Data, mostly from animal studies, suggest that for androgens to cause prostate cancer they must be aromatized to estrogen and act in concert with these estrogen metabolites. Androgen-receptor mediated activity of androgens and estrogen receptor-mediated effects of estrogen metabolites are likely to be necessary, but estrogen genotoxicity appears to be a probable critical factor as well. Only when all these mechanisms are active, may prostate carcinogenesis result. Convincing proof-of-concept studies are needed to definitively test this concept which, if proven, may lead to clinically feasible chemoprevention approaches interfering with these mechanisms.

Hormones and prostate carcinogenesis: Androgens and estrogens

Prostate cancer is the leading non-skin malignancy detected in US males and the second cause of death due to male cancer in the US. Androgenic hormones are generally believed to be causatively associated with prostate carcinogenesis, but human evidence, mostly epidemiological, for this is minimal. Circulating hormone levels are not associated with the risk of prostate cancer and neither are polymorphisms in various genes encoding the androgen metabolizing enzymes or androgen receptors. Evidence in support of the involvement of androgens in prostate cancer development is derived from clinical trials with 5α-reductase inhibitors, which reduced the risk by approximately 25%. Animal studies using rat models, however, provide clear evidence that testosterone can induce prostate cancer and can act as a strong tumor promoter in concert with genotoxic carcinogens. One such genotoxic factor may be 17β-estradiol, which is generated from testosterone by the aromatase enzyme. Estradiol can be converted to catecholestrogens, which through redox cycling, generate reactive metabolites that can adduct the DNA and potentially lead to mutations. Animal studies and limited human evidence suggest that estrogens can be involved in prostate carcinogenesis by such a genotoxic mechanism. However, how androgens exert their tumor-promoting effect is not clear. It is likely that hormonal and non-hormonal factors as well as genetic and non-genetic (environmental) factors interact in a highly complex and poorly understood manner to determine the risk of prostate cancer.

The impact of common genetic variations in genes of the sex hormone metabolic pathways on steroid hormone levels and prostate cancer aggressiveness

Our previous work suggested that there was no significant association between plasma steroid hormone levels and prostate cancer tumor grade at diagnosis. In this study, we systematically tested the hypothesis that inherited variations in the androgen and estrogen metabolic pathways may be associated with plasma levels of steroid hormones, or prostate cancer aggressiveness at diagnosis. Plasma hormone levels including total testosterone, total estradiol, and sex hormone-binding globulin were measured in a cohort of 508 patients identified with localized prostate cancer. D'Amico risk classification at diagnosis was also determined. A total of 143 single-nucleotide polymorphisms (SNPs) from 30 genes that are involved in androgen and estrogen metabolism were selected for analysis. The global association of genotypes with plasma hormone levels and prostate cancer aggressiveness (D'Amico risk classification) was statistically analyzed. Q values were estimated to account for multiple testing. We observed significant associations between plasma testosterone level and SNPs in HSD17B2 (rs1424151), HSD17B3 (rs9409407), and HSD17B1 (rs12602084), with P values of 0.002, 0.006, and 0.006, respectively. We also observed borderline significant associations between prostate aggressiveness at diagnosis and SNPs in AKR1C1 (rs11252845; P = 0.005), UGT2B15 (rs2045100; P = 0.007), and HSD17B12 (rs7932905; P = 0.008). No individual SNP was associated with both clinical variables. Genetic variants of genes in hormone metabolic pathways may influence plasma androgen levels or prostate cancer aggressiveness. However, it seems that the inherited variations affecting plasma hormone levels differ from those affecting disease aggressiveness.

Association between polymorphisms in cancer-related genes and early onset of esophageal adenocarcinoma

There is an increasing incidence of esophageal adenocarcinoma (EA) among younger people in the western populations. However, the association between genetic polymorphisms and the age of EA onset is unclear. In this study, 1330 functional/tagging single-nucleotide polymorphisms (SNPs) from 354 cancer-related genes were genotyped in 335 white EA patients. Twenty important SNPs that have the highest importance scores and lowest classification error rate were identified by the random forest algorithm to be associated with early onset of EA (age ≤ 55 years). Subsequent logistic regression analysis indicated that 10 SNPs (rs2070744 of NOS3, rs720321 of BCL2, rs17757541 of BCL2, rs11775256 of TNFRSF10A, rs1035142 of CASP8, rs2236302 of MMP14, rs4740363 of ABL1, rs696217 of GHRL, rs2445762 of CYP19A1, and rs11941492 of VEGFR2/KDR) were significantly associated with early onset of EA (≤55 vs >55 years, all P < .05 after adjusting for co-variates and false discovery rate). Among them, five SNPs in the NOS3, BCL2, TNFRSF10A, and CASP8 genes were known to be involved in apoptosis processes. In Kaplan-Meier analyses, rs2070744 of NOS3, rs720321 of BCL2, and rs1035142 of CASP8 were also significantly associated with early onset of EA. Moreover, there was a higher risk of developing EA at a younger age when one had more risk genotypes. In conclusion, polymorphisms in cancer-related genes, especially those in the apoptotic pathway, play an important role in the development of younger-aged EA in a dose-response manner.

Aromatase activity and bone loss in men

Aromatase is a specific component of the cytochrome P450 enzyme system responsible for the transformation of androgen precursors into estrogens. This enzyme is encoded by the CYP19A1 gene located at chromosome 15q21.2, that is, expressed in ovary and testis, but also in many extraglandular sites such as the placenta, brain, adipose tissue, and bone. The activity of aromatase regulates the concentrations of estrogens with endocrine, paracrine, and autocrine effects on target issues including bone. Importantly, extraglandular aromatization of circulating androgen precursors is the major source of estrogen in men. Clinical and experimental evidences clearly indicate that aromatase activity and estrogen production are necessary for longitudinal bone growth, the attainment of peak bone mass, pubertal growth spurt, epiphyseal closure, and normal bone remodeling in young individuals. Moreover, with aging, individual differences in aromatase activity may significantly affect bone loss and fracture risk in men.

Variation in the CYP19A1 gene and risk of colon and rectal cancer

CYP19A1, or aromatase, influences estrogen-metabolizing enzymes and may influence cancer risk. We examine variation in the CYP19A1 gene and risk of colorectal cancer using data from population-based case-control studies (colon n = 1,574 cases, 1,970 controls; rectal n = 791 cases, 999 controls). Four SNPs were statistically significantly associated with colon cancer and four were associated with rectal cancer. After adjustment for multiple comparisons, the AA genotype of rs12591359 was associated with an increased risk of colon cancer (OR 1.44 95% CI 1.16-1.80) and the AA genotype of rs2470144 was associated with a reduced risk of rectal cancer (OR 0.65 95% CI 0.50-0.84). Variants of CYP19A1 were associated with CIMP+ and CIMP+/KRAS2-mutated tumors. CT/TT genotypes of rs1961177 were significantly associated with an increased likelihood of a MSI+ colon tumor (OR 1.77 95% CI 1.26-2.37). We observed statistically significant interactions between genetic variation in NFκB1 and CYP19A1 for both colon and rectal cancer. Our data suggest the importance of CYP19A1 in the development of colon and rectal cancer and that estrogen may influence risk through an inflammation-related mechanism.

Estrogen receptor α and aromatase polymorphisms affect risk, prognosis, and therapeutic outcome in men with castration-resistant prostate cancer treated with docetaxel-based therapy

CONTEXT

Reactive estrogen species cause genotoxicity and interfere with docetaxel-mediated tubulin polymerization resulting in shortened survival in men with castrate-resistant prostate cancer (CRPC).

OBJECTIVE

We hypothesized that polymorphisms in estrogen synthesis and estrogen targets (i.e., CYP19 and ERα) would be linked to interindividual variation in CRPC risk, docetaxel response, and overall survival in men with CRPC.

MATERIALS AND METHODS

Patients with CRPC (n=115) treated with docetaxel, single-agent thalidomide (n=42), or healthy controls (n=289) were genotyped for the CYP19 R264C (rs700519) and the ERα PvuII T>C (rs2234693) and XbaI A>G (rs9340799) polymorphisms.

RESULTS

Patients carrying two copies of ERα polymorphisms had shorter progression-free survival on docetaxel than other patients (median survival difference ≥ 3.1 months; P ≤ 0.036). When the analysis was limited to nonobese patients, the relationship between the ERα XbaI A>G polymorphism and PFS improved (median survival difference = 3.5 months; P = 0.0078). The CYP19 R264C variant was related to the duration of survival after docetaxel in patients who were >70 years old (median survival difference =10.6 months; P=0.041). Both ERα polymorphisms were also associated with increases in CRPC risk [P ≤ 0.032; double variants vs. wild-type odds ratio ≥ 2.6], and the association with the ERα PvuII T>C also improved in those men who were <70 years old (P = 0.0073; odds ratio = 3.0).

CONCLUSIONS

This study demonstrates that estrogen-related genetic variation affects docetaxel clinical response and that this relationship is dependent on age and body-type in men with CRPC. Moreover, this study suggests ERα polymorphisms confer risk of developing prostate cancer, especially in men under 70 years of age.

Aromatase activity and bone loss

Aromatase is a specific component of the cytochrome P450 enzyme system that is responsible for the transformation of C19 androgen precursors into C18 estrogenic compounds. This enzyme is encoded by the CYP19A1 gene located at chromosome 15q21.2, that is expressed in ovary and testis not only but also in many extraglandular sites such as the placenta, brain, adipose tissue, and bone. The regulation of the level and activity of aromatase determines the levels of estrogens that have endocrine, paracrine, and autocrine effects on target issues including bone. Importantly, extraglandular aromatization of circulating androgen precursors is the major source of estrogen not only in men (since only 15% of circulating estradiol is released directly by the testis) but also in women after the menopause. Several lines of clinical and experimental evidence now clearly indicate that aromatase activity and estrogen production are necessary for longitudinal bone growth, attainment of peak bone mass, the pubertal growth spurt, epiphyseal closure, and normal bone remodeling in young individuals. Moreover, with aging, individual differences in aromatase activity and thus in estrogen levels may significantly affect bone loss and fracture risk in both genders.

Trends in distant-stage breast, colorectal, and prostate cancer incidence rates from 1992 to 2004: potential influences of screening and hormonal factors

Differential utilization of cancer screening between populations could lead to changes in cancer disparities. Evaluating incidence rates trends is one means of monitoring these disparities. Using Surveillance, Epidemiology, and End Results data, we compared annual percent changes (APC) in age-adjusted incidence rates of distant-stage breast, colorectal, and prostate cancer between non-Hispanic whites (NHW) and African Americans (AA). From 1992 to 2004, distant-stage breast cancer incidence rates remained essentially constant among both AA and NHW women, though rates were 30-90% higher among AA women throughout. NHW men and women experienced declines in distant-stage colorectal cancer incidence rates [APC = -1.6, 95% confidence interval (CI) -2.3, -0.9], but AA men and women did not. Distant-stage prostate cancer incidence rates declined for both AA (APC = -5.8, 95% CI -7.9, -3.8) and NHW (APC = -5.1, 95% CI -6.7, -3.4). Despite now having nearly equal mammography screening rates, the persistent breast cancer disparity observed among AAs compared to NHWs may be due to the greater susceptibility of AAs to more aggressive tumors, particularly hormone-receptor-negative disease, which is more difficult to detect by mammography. For colorectal cancer, greater utilization of screening tests among NHWs vs. AAs is likely a primary contributor to the observed widening disparity. Wider recognition of AA race as a prostate cancer risk factor may contribute to the narrowing disparity in the incidence of disease.