| 1. |
- Axelsson, Jonatan, et al.
(author)
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Gene-environment interaction and male reproductive function.
- 2010
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In: Asian Journal of Andrology. - : Medknow. - 1008-682X .- 1745-7262. ; 12, s. 298-307
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Journal article (peer-reviewed)abstract
- As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism, but the number of studies is still limited. This type of interaction studies may improve our understanding of normal physiology and help us to identify the risk factors to male reproductive malfunction. We also shortly discuss other aspects of gene-environment interaction specifically associated with the issue of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity in the offspring.
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| 2. |
- Bentmar Holgersson, Magdalena, et al.
(author)
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Androgen receptor polymorphism dependent variation in prostate specific antigen concentrations of European men.
- 2014
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In: Cancer Epidemiology Biomarkers & Prevention. - 1538-7755. ; 23:10, s. 2048-2056
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Journal article (peer-reviewed)abstract
- Background Androgens acting via the androgen receptor (AR) stimulate production of prostate specific antigen (PSA), which is a clinical marker of prostate cancer (PCa). Since genetic variants in the AR may have a significant impact on the risk of being diagnosed with PCa, the aim was to investigate if AR-variants were associated with the risk of having PSA above clinically used cut-off thresholds of 3 or 4 ng/mL in men without PCa. Methods Men without PCa history (n=1744) were selected from the European Male Ageing Study (EMAS) cohort of 40-80 year old men from 8 different European centers. Using linear and logistic regression models, with age and center as covariates, we investigated whether AR-variants (CAG repeat-length and/or SNP genotype) were associated with having serum PSA concentrations above 3 or 4 ng/mL, which often are set as cut-off concentrations for further investigation of PCa. Results Carriers of the SNP rs1204038 A-allele (16% of the men) were more likely to have PSA>3 and 4 ng/mL (OR; 95%CI 1.65; 1.13-2.40 and 1.87; 1.18-2.96, respectively) than G-allele carriers. They also had shorter CAG-repeats (median 20 vs. 23, p<0.0005), but CAG repeat length per se did not affect the PSA concentrations. Conclusion The A-allele of the SNP rs1204038 gives a 65% higher risk of having PSA above 3 ng/mL than the G-allele in men without PCa, and thereby an increased risk of being referred for further examination on suspicion of PCa. Impact Serum PSA as a clinical marker could be improved by adjustment for AR-genotype.
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| 3. |
- Björk, Christel, et al.
(author)
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Persistent organic pollutants have dose and CAG repeat length dependent effects on androgen receptor activity in vitro
- 2011
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In: Reproductive Toxicology. - : Elsevier BV. - 0890-6238 .- 1873-1708. ; 32, s. 293-297
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Journal article (peer-reviewed)abstract
- Recently, the effect of exposure to persistent organic pollutants (POPS) on sperm concentration was only seen in men with a short androgen receptor (AR) gene CAG repeat. In order to investigate whether these effects could be observed also in vitro, we tested the impact of 2,2’,4,4’,5,5’-hexachlorobiphenyl (CB-153) and 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (4,4’-DDE) on 5 alpha-dihydrotestosterone activated ARs containing 16,22 and 28 CAG repeats, respectively. Single exposure to 4,4’-DDE had the most pronounced effect on the AR activity containing 16 CAG repeats, whereas 28 CAG was the most sensitive variant when a mixture of the two compounds was added. Thus, our in vitro results have confirmed the in vivo data indicating a CAG repeat length dependent effect of endocrine disrupters on the AR activity.
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| 4. |
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| 5. |
- Brokken, Leon, et al.
(author)
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Association between polymorphisms in the aryl hydrocarbon receptor repressor gene and disseminated testicular germ cell cancer.
- 2013
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In: Frontiers in Endocrinology. - : Frontiers Media SA. - 1664-2392. ; 4:Feb.,14
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Journal article (peer-reviewed)abstract
- In the Western world, testicular germ cell cancer (TGCC) is the most common malignancy of young men. The malignant transformation of germ cells is thought to be caused by developmental and hormonal disturbances, probably related to environmental and lifestyle factors because of rapidly increasing incidence of TGCC in some countries. Additionally, there is a strong genetic component that affects susceptibility. However, genetic polymorphisms that have been identified so far only partially explain the risk of TGCC. Many of the persistent environmental pollutants act through the aryl hydrocarbon receptor (AHR). AHR signaling pathway is known to interfere with reproductive hormone signaling, which is supposed to play a role in the pathogenesis and invasive progression of TGCC. The aim of the present study was to identify whether AHR-related polymorphisms were associated with risk as well as histological and clinical features of TGCC in 367 patients and 537 controls. Haplotype-tagging single-nucleotide polymorphisms (SNPs) were genotyped in genes encoding AHR and AHR repressor (AHRR). Binary logistic regression was used to calculate the risk of TGCC, non-seminoma versus seminoma, and metastasis versus localized disease. Four SNPs in AHRR demonstrated a significant allele association with risk to develop metastases (rs2466287: OR = 0.43, 95% CI 0.21-0.90; rs2672725: OR = 0.49, 95% CI: 0.25-0.94; rs6879758: OR = 0.27, 95% CI: 0.08-0.92; rs6896163: OR = 0.34, 95% CI: 0.12-0.98). This finding supports the hypothesis that compounds acting through AHR may play a role in the invasive progression of TGCC, either directly or through modification of reproductive hormone action.
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| 6. |
- Brokken, Leon, et al.
(author)
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Association of polymorphisms in genes encoding hormone receptors ESR1, ESR2 and LHCGR with the risk and clinical features of testicular germ cell cancer.
- 2012
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In: Molecular and Cellular Endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 351:2, s. 279-285
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Journal article (peer-reviewed)abstract
- Testicular germ cell cancer (TGCC) is the most common malignancy in young men. Genetic variants known to be associated with risk of TGCC only partially account for the observed familial risks. We aimed to identify additional polymorphisms associated with risk as well as histological and clinical features of TGCC in 367 patients and 214 controls. Polymorphisms in ESR2 (rs1256063; OR=0.53, 95% CI: 0.35-0.79) and LHCGR (rs4597581; OR=0.68, 95% CI: 0.51-0.89, and rs4953617; OR=1.88, 95% CI: 1.21-2.94) associated with risk of TGCC. Polymorphisms in ESR1 (rs9397080; OR=1.85, 95% CI: 1.18-2.91) and LHCGR (rs7371084; OR=2.37, 95% CI: 1.26-4.49) associated with risk of seminoma and metastasis, respectively. SNPs in ESR1 (rs9397080) and LHCGR (rs7371084) were predictors of higher LH levels and higher androgen sensitivity index in healthy subjects. The results suggest that polymorphisms in ESR1, ESR2 and LHCGR contribute to the risk of developing TGCC, histological subtype, and risk to metastasis.
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| 7. |
- Brokken, Leon, et al.
(author)
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Interactions between polymorphisms in the aryl hydrocarbon receptor signalling pathway and exposure to persistent organochlorine pollutants affect human semen quality.
- 2014
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In: Reproductive Toxicology. - : Elsevier BV. - 1873-1708 .- 0890-6238. ; 49:Jul 30, s. 65-73
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Journal article (peer-reviewed)abstract
- Persistent organic pollutants (POPs) may affect male reproductive function. Many dioxin-like POPs exert their effects by activation of the aryl hydrocarbon receptor (AHR) signalling pathway. We analysed whether gene-environment interactions between polymorphisms in AHR (R554K) and AHR repressor (AHRR P185A) and serum levels of markers of POP exposure 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (p,p'-DDE) and 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) are associated with 21 parameters of male reproductive function in 581 proven-fertile European and Greenlandic men. In Greenlandic men, AHR variants significantly modified the association between serum levels of both p,p'-DDE and CB-153 and inhibin B levels, sperm chromatin integrity, and seminal zinc levels. In the total cohort, interactions between AHRR variants and serum levels of CB-153 were associated with sperm chromatin integrity and the expression of the pro-apoptotic marker protein Fas. The data indicate that susceptibility to adverse effects of POP exposure on male reproductive function is dependent on polymorphisms in genes involved in AHR signalling.
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| 8. |
- Brokken, Leon, et al.
(author)
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Non-linear association between androgen receptor CAG and GGN repeat lengths and reproductive parameters in fertile European and Inuit men.
- 2013
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In: Molecular and Cellular Endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 370:1-2, s. 163-171
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Journal article (peer-reviewed)abstract
- Recently the dogma that there is an inverse linear association between androgen receptor (AR) CAG and GGN polymorphisms and receptor activity has been challenged. We analysed the pattern of association between 21 male reproductive phenotypes and AR CAG/GGN repeat lengths in 557 proven-fertile men. A linear association was only found between sperm DNA fragmentation index (DFI) and CAG length, and between inhibin B and GGN length. Men with longer CAG then the reference (22-24), had higher oestradiol levels, whereas men with shorter CAG stretches had a higher DFI and a higher proportion of Fas-positive germ cells. Subjects with either short or long CAG had increased seminal levels of prostate-specific antigen and neutral α-glucosidase activity. Compared to men with the median GGN length of 23, those with shorter GGN repeats had higher levels of inhibin B, higher proportions of normal and progressive sperm, and a higher fraction of Fas-positive sperm, while men with longer GGN had higher oestradiol levels. These data indicate that at least for some markers of male reproductive function the association with CAG or GGN repeat length is curvilinear.
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| 9. |
- Bungum, Mona, et al.
(author)
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Polymorphisms in the protein C inhibitor gene in in vitro fertilization failure.
- 2010
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In: Fertility and Sterility. - : Elsevier BV. - 1556-5653 .- 0015-0282. ; 93:1, s. 277-279
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Journal article (peer-reviewed)abstract
- The aim of this study was to determine whether total fertilization failure in human IVF can be partially explained by alterations in the gene that codes for protein C inhibitor. Forty-six men had IVF total fertilization failure and 51 controls with normal fertilization were screened for mutations in the protein C inhibitor gene by direct sequencing. The main finding was that in men involved in total fertilization failure, a heterozygous adenosine/guanine (A/G) base combination in position 1389 (rs2069990) (exon 6) in the protein C inhibitor gene was significantly more common compared with controls (10.9% vs. 0).
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| 10. |
- Dalgaard, Marlene D., et al.
(author)
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A genome-wide association study of men with symptoms of testicular dysgenesis syndrome and its network biology interpretation
- 2012
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In: Journal of Medical Genetics. - : BMJ. - 0022-2593 .- 1468-6244. ; 49:1, s. 58-65
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Journal article (peer-reviewed)abstract
- Background Testicular dysgenesis syndrome (TDS) is a common disease that links testicular germ cell cancer, cryptorchidism and some cases of hypospadias and male infertility with impaired development of the testis. The incidence of these disorders has increased over the last few decades, and testicular cancer now affects 1% of the Danish and Norwegian male population. Methods To identify genetic variants that span the four TDS phenotypes, the authors performed a genome-wide association study (GWAS) using Affymetrix Human SNP Array 6.0 to screen 488 patients with symptoms of TDS and 439 selected controls with excellent reproductive health. Furthermore, they developed a novel integrative method that combines GWAS data with other TDS-relevant data types and identified additional TDS markers. The most significant findings were replicated in an independent cohort of 671 Nordic men. Results Markers located in the region of TGFBR3 and BMP7 showed association with all TDS phenotypes in both the discovery and replication cohorts. An immunohistochemistry investigation confirmed the presence of transforming growth factor beta receptor type III (TGFBR3) in peritubular and Leydig cells, in both fetal and adult testis. Single-nucleotide polymorphisms in the KITLG gene showed significant associations, but only with testicular cancer. Conclusions The association of single-nucleotide polymorphisms in the TGFBR3 and BMP7 genes, which belong to the transforming growth factor b signalling pathway, suggests a role for this pathway in the pathogenesis of TDS. Integrating data from multiple layers can highlight findings in GWAS that are biologically relevant despite having border significance at currently accepted statistical levels.
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| 11. |
- Eberhard, Jakob, et al.
(author)
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Emotional disorders in testicular cancer survivors in relation to hypogonadism, androgen receptor polymorphism and treatment modality.
- 2010
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In: Journal of Affective Disorders. - : Elsevier BV. - 1573-2517 .- 0165-0327. ; 122, s. 260-266
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Journal article (peer-reviewed)abstract
- PURPOSE: It has been documented that testicular germ cell cancer (TGCC) patients may be at increased risk of developing emotional distress (EMD). Hence, the aim of the present study was to investigate whether EMD is related to the presence of hypogonadism, androgen receptor (AR) polymorphism and/or treatment intensity. PATIENTS AND METHODS: Three to five years after treatment, testosterone and luteinizing hormone (LH) levels were measured in 165 TGCC patients. These patients also completed a questionnaire concerning mental health. EMD was measured by the Hospital Anxiety and Depression Scale (HADS). The androgen receptor (AR) gene has two polymorphic regions in exon I; glutamine encoding CAG and glycine encoding GGN repeats. Association between emotional disorders and AR polymorphisms as well as type of treatment was assessed. RESULTS: Neither anxiety (OR 1.0; 95% CI 0.40-2.4) nor depression (OR 1.1; 95% CI 0.20-6.4) were overrepresented in biochemically hypogonadal TGCC patients and no association between AR polymorphisms and EMD was found. Patients treated with >/=5 cycles of cisplatinum based chemotherapy due to refractory or relapsed disease were more prone to experiencing symptoms of anxiety (p=0.006), but not depression (p=0.38). CONCLUSIONS: Biochemical hypogonadism and AR polymorphism do not seem to be risk factors for EMD in TGCC patients. Patients with refractory or relapsed disease receiving >/=5 cycles of cisplatinum based chemotherapy may, to a higher degree than patients receiving less intense therapy, suffer from anxiety.
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| 12. |
- Giwercman, Aleksander, et al.
(author)
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Environmental factors and testicular function.
- 2011
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In: Best Practice and Research in Clinical Endocrinology and Metabolism. - : Elsevier BV. - 1521-690X. ; 25:2, s. 391-402
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Journal article (peer-reviewed)abstract
- Over the last decades there has been a dramatic increase in the incidence of some diseases associated with the male reproductive system, including poor semen quality, testicular cancer and congenital developmental abnormalities such as cryptorchidism and hypospadias, malformations of the urethra and scrotum respectively. Based on these observations one recurring theme is the concern that certain environmental chemicals and lifestyle related factors may play a role. Early fetal life is a particularly critical time period, when the endocrine system is established and organs are developing. Although available data does not yet allow recommending, evidence based, prophylactic and/or therapeutic measures to eliminate or reduce the possible negative impact of environment/lifestyle on the male reproductive capacity, it is prudent to limit exposures of people to hormonally active chemicals.
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| 13. |
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| 14. |
- Isaksson, Sigrid, et al.
(author)
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Inhibin B concentration is predictive for long-term azoospermia in men treated for testicular cancer.
- 2014
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In: Andrology. - : Wiley. - 2047-2927 .- 2047-2919. ; 2:2, s. 252-258
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Journal article (peer-reviewed)abstract
- Azoospermia is a serious potential side effect following treatment for testicular cancer (TC). Our purpose was to examine possible predictors of long-term azoospermia in TC survivors. Ejaculates and blood samples were obtained from 217 patients at post-orchidectomy but before further treatment (T0 ) and/or at one or more of the time points 6, 12, 24, 36-60 months after treatment (T6 , T12 , T24 , T36-60 ). All patients delivered ejaculates at T36-60 , of which 117 also had confirmed presence of spermatozoa in the ejaculate at T0 , enabling longitudinal analyses. Types of therapy, cryptorchidism and Inhibin B before and after treatment were evaluated in relation to risk of azoospermia at T36 . Inhibin B levels at T6 , T12 and T24 were predictors of azoospermia at T36 with cut-off levels at 49.7, 55.9 and 97.8 ng/L respectively (sensitivity 100%, specificity 57-78%). The frequency of azoospermia in all patients at T36-60 was 7.8% (95% CI 4.9-12%). As compared to surveillance patients, only those receiving >4 cycles of chemotherapy or ≥4 cycles of chemotherapy + radiotherapy (RT) had increased risk of long-term azoospermia (63% vs. 4.4% in the surveillance group; p = 0.0018). In conclusion, all patients with sperm production at post-orchidectomy but before further treatment and Inhibin B >56 ng/L 12 months after treatment had sperm production 3 years post-treatment. Eight per cent of TC survivors had azoospermia 3-5 years post-treatment, with highest risk in those receiving >4 cycles of chemotherapy or ≥4 cycles of chemotherapy in combination with RT.
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| 15. |
- Kvist, Linus, et al.
(author)
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Exposure to persistent organic pollutants and sperm sex chromosome ratio in men from the Faroe Islands.
- 2014
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In: Environment International. - : Elsevier BV. - 1873-6750 .- 0160-4120. ; 73, s. 359-364
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Journal article (peer-reviewed)abstract
- People in the Arctic as well as fishermen on the polluted Swedish east coast are highly exposed to persistent organic pollutants (POPs). These compounds have been shown to affect the sperm Y:X chromosome ratio. In present study, the aim was to investigate whether polychlorinated biphenyl (PCB) congeners and 1,1,-dichloro-2,2,-bis(p-chlorophenyl)ethane (p,p'-DDE) influence sperm sex chromosome ratio in Faroese men, and whether these men differ regarding Y:X ratio compared to Greenland Inuit and Swedish fishermen. The study population (n=449) consisted of young men from the general population (n=276) as well as proven fertile men (n=173). The Y:X ratio was assessed by fluorescent in situ hybridization. Serum concentrations of POPs were measured using gas chromatography. Associations between POP concentrations and Y:X ratio were calculated using linear and non-linear regression models as well as trend analysis and pairwise comparison of exposure data categorized into quartiles. The selected POPs were associated with Y:X ratio in fertile Faroese men, but not in the total population; p,p'-DDE (95% CI for B=-0.005 to -0.001, p=0.005) and ΣPCB (95% CI for B=-0.005 to -0.001, p=0.012). Since p,p'-DDE and ΣPCB correlated significantly (r=0.927, p<0.001), the results involving the exposure variables can be regarded as a single finding. The Y:X ratio for the total Faroese population was 0.500±0.018, which was statistically significantly lower than in both Inuit and Swedish fishermen (0.512 for both). In conclusion, Faroese men presented with lower Y:X ratio than Greenland Inuit and Swedish fishermen. Although no direct health effects are expected due to the lower Faroese Y:X ratio, it could be indicative of adverse effects on the reproductive system.
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| 16. |
- Kvist, Linus, et al.
(author)
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Serum levels of perfluorinated compounds and sperm Y:X chromosome ratio in two European populations and in Inuit from Greenland.
- 2012
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In: Reproductive Toxicology. - : Elsevier BV. - 1873-1708 .- 0890-6238.
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Journal article (peer-reviewed)abstract
- This study investigated whether perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS), which exhibit reproductive toxicity in experimental animals, affect sperm sex chromosome ratio. The Y:X ratio was determined by fluorescence in situ hybridization. Serum concentrations of PFOA and PFOS were measured in 607 men from Greenland, Poland and Ukraine using liquid chromatography-tandem mass spectrometry. Data was analyzed by linear and nonlinear regression. We observed no associations between PFOA and Y:X ratio (p=0.845 in a linear model, p=0.296 in a nonlinear model). A positive nonlinear association between PFOS and Y:X ratio was observed (p=0.016), with no association in a linear model (p=0.118). Analyzing the populations separately, a negative trend between categorized PFOS exposure and Y:X ratio was observed for the Inuit (B=-0.002, p=0.044). In conclusion, there was a negative trend between Y:X ratio and PFOS in the Inuit, while there was no association between PFOA and the Y:X ratio in adult men.
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| 17. |
- Lindgren, Ida, et al.
(author)
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Association between follicle-stimulating hormone receptor polymorphisms and reproductive parameters in young men from the general population.
- 2012
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In: Pharmacogenetics & Genomics. - 1744-6872. ; 22:9, s. 667-672
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Follicle-stimulating hormone (FSH) regulates gametogenesis through binding to its receptor (FSHR). In women, the Thr307Ala and Asn680Ser polymorphisms in the FSHR gene affect reproductive function, but it is not clear whether they have any impact on spermatogenesis and have mainly been investigated in infertile men of varying ages. The aim of the present study was therefore to examine whether these genetic variants of the FSHR influence reproductive parameters in men from the general population. METHODS: Men aged 17-20 years (n=313) were genotyped. All men provided a semen sample and a blood sample for hormonal measurements and DNA extraction. They underwent a medical examination and analyses of possible associations between Thr307Ala and Asn680Ser polymorphisms and hormonal and sperm parameters were subsequently carried out. RESULTS: Men homozygous for Thr307/Asn680 had a lower mean serum FSH concentration (3.07 vs. 3.65 IU/l, P=0.009), and higher mean serum estradiol (94.0 vs. 86.1 pmol/l, P=0.001), sex hormone-binding globulin (33.6 vs. 31.3 nmol/l, P<0.0001), and total testosterone (19.1 vs.17.9 nmol/l, P<0.0001) concentrations compared with men with other genotypes. In addition, sperm concentrations (71.9×10 vs. 70.8×10/ml, P=0.040) and the total sperm counts were higher (212×10 vs. 206×10, P<0.0001) and their testes volumes were larger (left: 11.5 vs. 11.0 ml, P<0.0001; right: 12.4 vs. 11.6 ml, P=0.002). CONCLUSION: As in women, the results from the present study indicate that variants of the FSHR influence reproductive parameters in men.
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| 18. |
- Linnér, Carl, et al.
(author)
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Estrogen receptor alpha single nucleotide polymorphism as predictor of diabetes type 2 risk in hypogonadal men.
- 2013
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In: The Aging Male. - : Informa UK Limited. - 1473-0790 .- 1368-5538. ; 16:2, s. 52-57
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Journal article (peer-reviewed)abstract
- Abstract Estradiol (E2) is, apart from its role as a reproductive hormone, also important for cardiac function and bone maturation in both genders. It has also been shown to play a role in insulin production, energy expenditure and in inducing lipolysis. The aim of the study was to investigate if low circulating testosterone or E2 levels in combination with variants in the estrogen receptor alpha (ESR1) and estrogen receptor beta (ESR2) genes were of importance for the risk of type-2 diabetes. The single nucleotide polymorphisms rs2207396 and rs1256049, in ESR1 and ESR2, respectively, were analysed by allele specific PCR in 172 elderly men from the population-based Tromsø study. The results were adjusted for age. In individuals with low total (≤11 nmol/L) or free testosterone (≤0.18 nmol/L) being carriers of the variant A-allele in ESR1 was associated with 7.3 and 15.9 times, respectively, increased odds ratio of being diagnosed with diabetes mellitus type 2 (p = 0.025 and p = 0.018, respectively). Lower concentrations of E2 did not seem to increase the risk of being diagnosed with diabetes. In conclusion, in hypogonadal men, the rs2207396 variant in ESR1 predicts the risk of type 2 diabetes.
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| 19. |
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| 20. |
- Nenonen, Hannah, et al.
(author)
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CAG repeat number is not inversely associated with androgen receptor activity in vitro.
- 2010
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In: Molecular Human Reproduction. - : Oxford University Press (OUP). - 1460-2407 .- 1360-9947. ; 16, s. 153-157
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Journal article (peer-reviewed)abstract
- A negative linear association between androgen receptor (AR) function and the CAG repeat numbers is generally assumed. However, in vivo data concerning the association between CAG number and androgenic effects have been conflicting. Since former in vitro studies mostly have been based on extreme CAG lengths and reporter-systems containing viral promoters, the objective of this study was to investigate ARs with CAG lengths within normal range (16, 22 and 28) in a reporter-assay with the human prostate specific antigen promoter as target. We also wished to elucidate whether the interpretation of the results was depending on the methods used for adjustment of transfection efficiency and protein content. With ss-galactosidase as transfection control, 22CAG had the highest activity (set to 100%) compared to 16CAG (mean 78% [range 41- 132], p=0.005) and 28CAG (68% [26-162], p=0.006), whereas renilla-luciferase resulted in 16CAG behaving similar to 22CAG (104% [56- 165], p=0.7) and 28CAG having lower activity (59% [33-101], p=0.004). In these experiments, also the empty vector displayed considerable background activity. When adjusting for AR protein, the 22CAG genotype had the highest activity; 16CAG and 28CAG displaying 20% (10-47, p<0.0001) and 12% (5-21, p<0.0001) thereof. Similar results were obtained with adjustment for total protein Thus, by normalising for AR-content, contrary to various control vectors, the highest AR activity was confined to the 22CAG and not 16 CAG, which may at least partly explain the discrepancy in data aiming to link physiological conditions to CAG repeat length.
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| 21. |
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| 22. |
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| 23. |
- Nenonen, Hannah, et al.
(author)
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Non-linear association between androgen receptor CAG repeat length and risk of male subfertility - a meta-analysis.
- 2011
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In: International Journal of Andrology. - : Wiley. - 1365-2605 .- 0105-6263. ; Jul 1, s. 327-332
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Journal article (peer-reviewed)abstract
- Summary The CAG repeat in the androgen receptor (AR) has been widely studied in association with male infertility, but the results are conflicting. In a recent meta-analysis, infertile men had <1 repeat longer CAG stretch than fertile men when analysed in a linear regression model assuming that AR function diminishes with increasing CAG length. However, in vitro, a non-linear activity pattern was recently demonstrated so that ARs containing short and long stretches, respectively, displayed lower activity than the AR of median length. These results prompted us to explore the possible association between CAG number and male infertility risk in a stratified manner on the basis of data from the mentioned meta-analysis and subjects from our clinical unit. The study population included 3915 men, 1831 fertile and 2084 infertile. Data were divided into three categories: CAG < 22, CAG 22-23 (reference) and CAG > 23 and analysed in a binary logistic regression model. Men with CAG < 22 and CAG > 23 had 20% increased odds ratio of infertility compared with carriers of the median lengths [for CAG < 22: p = 0.03, 95% confidence interval (CI): 1.02-1.39; for CAG > 23: p = 0.02, 95% CI: 1.03-1.44]. These results show that an alternative model to a linear one for the genotype-phenotype association in relation to AR CAG repeats is likely, as lengths close to the median confine lowest risk of infertility.
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| 24. |
- Romerius, Patrik, et al.
(author)
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Estrogen receptor alpha single nucleotide polymorphism modifies the risk of azoospermia in childhood cancer survivors
- 2011
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In: Pharmacogenetics & Genomics. - 1744-6872. ; 21:5, s. 263-269
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Cancer treatment in childhood leads to permanent azoospermia in a significant number of boys and those who are diagnosed with cancer before puberty do not have the option of pretreatment cryopreservation of spermatozoa. However, there is an interindividual variation in the sensitivity to gonadotoxic effects of cancer therapy, which probably is due to genetic factors. Identification of genetic markers for the risk of azoospermia in childhood cancer survivors may help in identifying boys to whom testicular cryopreservation should be offered. METHODS: Fifty-one single nucleotide polymorphisms (SNPs) being markers of 12 different haplotype blocks in the androgen receptor, estrogen receptor (ER) α and ER β genes were examined in 127 adult childhood cancer survivors. RESULTS: In ERα, markers of one specific haplotype block (rs2207396, rs9340958, rs9340978) were associated with an increased risk of azoospermia. Compared with those with the GG genotype, patients being heterozygous for the A allele in rs2207396 had a significantly increased risk of azoospermia [odds ratio (OR): 3.8; 95% confidence interval: 1.5-9.5; P=0.008], this OR being even higher in the subgroup treated with alkylating drugs (OR: 8.8; 95% confidence interval: 2.1-36; P=0.004). In this subgroup, 48% of the patients carried the A allele of rs2207396, this proportion being 70% among the azoospermic patients. CONCLUSION: Use of genetic markers of high risk of posttreatment azoospermia may, in the future, prove an important clinical tool in selection of boys to whom preservation of testicular tissue before cancer therapy should be offered.
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| 25. |
- Romerius, Patrik, et al.
(author)
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Estrogen receptor α single nucleotide polymorphism modifies the risk of azoospermia in childhood cancer survivors
- 2011
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In: Pharmacogenetics & Genomics. - 1744-6872 .- 1744-6880. ; 21:5, s. 263-269
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Cancer treatment in childhood leads to permanent azoospermia in a significant number of boys and those who are diagnosed with cancer before puberty do not have the option of pretreatment cryopreservation of spermatozoa. However, there is an interindividual variation in the sensitivity to gonadotoxic effects of cancer therapy, which probably is due to genetic factors. Identification of genetic markers for the risk of azoospermia in childhood cancer survivors may help in identifying boys to whom testicular cryopreservation should be offered. METHODS: Fifty-one single nucleotide polymorphisms (SNPs) being markers of 12 different haplotype blocks in the androgen receptor, estrogen receptor (ER) α and ER β genes were examined in 127 adult childhood cancer survivors. RESULTS: In ERα, markers of one specific haplotype block (rs2207396, rs9340958, rs9340978) were associated with an increased risk of azoospermia. Compared with those with the GG genotype, patients being heterozygous for the A allele in rs2207396 had a significantly increased risk of azoospermia [odds ratio (OR): 3.8; 95% confidence interval: 1.5-9.5; P=0.008], this OR being even higher in the subgroup treated with alkylating drugs (OR: 8.8; 95% confidence interval: 2.1-36; P=0.004). In this subgroup, 48% of the patients carried the A allele of rs2207396, this proportion being 70% among the azoospermic patients. CONCLUSION: Use of genetic markers of high risk of posttreatment azoospermia may, in the future, prove an important clinical tool in selection of boys to whom preservation of testicular tissue before cancer therapy should be offered.
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