| 1. |
- Aschim, EL, et al.
(författare)
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Linkage between cryptorchidism, hypospadias, and GGN repeat length in the androgen receptor gene
- 2004
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 89:10, s. 5105-5109
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Tidskriftsartikel (refereegranskat)abstract
- Although sufficient androgen receptor (AR) function is crucial for normal male sexual differentiation, single-point mutations in the AR gene are infrequent in the two most common male congenital malformations, hypospadias and cryptorchidism. Because polymorphic CAG and GGN segments regulate AR function, we investigated whether there was any association between these polymorphisms and mentioned malformations. Genotyping was performed by direct sequencing of DNA from patients diagnosed with hypospadias (n = 51) and cryptorchidism ( n = 23) and controls ( n = 210). The subjects with hypospadias were divided into subgroups of glanular, penile, and penoscrotal hypospadias. Median GGN lengths were significantly higher ( 24 vs. 23) among both subjects with cryptorchidism, compared with controls ( P = 0.001), and those with penile hypospadias, compared with either controls ( P = 0.003) or glanular and penoscrotal hypospadias combined ( P = 0.018). The frequency of cases with GGN 24 or more vs. GGN = 23, differed significantly among those with cryptorchidism (65/35%), compared with controls (31/54%) ( P = 0.012), and among subjects with penile hypospadias (69/31%), compared with either controls ( P = 0.035) or glanular or penoscrotal hypospadias combined (32/55%) ( P = 0.056). There were no significant differences in CAG lengths between the cases and controls. Our findings indicate an association between GGN length and the risk of cryptorchidism and penile hypospadias, both conditions considered consequences of low androgenicity.
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| 2. |
- Bentmar Holgersson, Magdalena, et al.
(författare)
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Lower prostate cancer risk in Swedish men with the androgen receptor E213 A-allele
- 2017
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Ingår i: Cancer Causes & Control. - : Springer Science and Business Media LLC. - 0957-5243 .- 1573-7225. ; 28:3, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- In a previous population-based study on 3369 European men with self-reported prostate cancer (PCa), it was shown that androgen receptor (AR) haplotype designated H2 was associated with high levels of serum PSA (prostate-specific antigen) concentration, and, at the same time, with low risk for PCa. The aim of this study was to replicate this finding in other cohorts, with registry-based cancer diagnosis. Using data from two population-based cohorts; the Malmo Diet and Cancer Study (MDCS, n = 12,121) and the Swedish Osteoporotic fractures in men study (MrOS, n = 1,120), 628 men with PCa and 1,374 controls were identified and genotyped. PCa data were collected from the Swedish national cancer registry. PCa odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for carriers of the particular AR haplotype, tagged by the rs6624304 T-allele. The 15% of men who were carriers of the AR haplotype H2 had approximately one-third lower risk for PCa diagnosis compared to those with the most common H1 variant (OR 0.65; 95% CI 0.45-0.94; p = 0.021). The same trend, although not statistically significant (OR 0.75; 95% CI 0.47-1.24; p = 0.275), was observed in MrOS Sweden. When both cohorts were merged, an even more significant result was observed (OR 0.68; 95% CI 0.51-0.90; p = 0.008). Swedish men with the variant AR haplotype H2, tagged by rs6624304, have significantly lower risk of PCa compared to those with the more common variant.
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| 3. |
- Lundwall, Åke, et al.
(författare)
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A frequent allele codes for a truncated variant of semenogelin I, the major protein component of human semen coagulum
- 2003
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Ingår i: Molecular Human Reproduction. - : Oxford University Press (OUP). - 1460-2407. ; 9:6, s. 345-350
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Tidskriftsartikel (refereegranskat)abstract
- Human semen coagulum predominantly consists of high molecular mass complexes of the seminal vesicle secreted semenogelin I (SgI) and semenogelin II (SgII). Here we describe a previously unknown variant of the SgI gene that is present at an allele frequency of similar to3% in the Swedish population. It gives rise to a protein with a molecular mass of 43 kDa, SgI(43), which compared with the 50 kDa variant, SgI(50), is lacking a tandem repeat of 60 amino acid residues that was probably deleted by homologous recombination. In spite of the size difference, SgI(43) has many properties in common with SgI(50), such as a very high iso-electric point and susceptibility to proteolytic degradation by prostate-specific antigen. Heterozygous carriers of the SgI(43) allele neither show impaired fertility nor do they significantly differ from individuals homozygous for I SgI(50) with respect to sperm parameters such as semen volume, sperm count and fraction of motile spermatozoa.
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| 4. |
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| 5. |
- Ruhayel, Yasir, et al.
(författare)
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Male infertility and prostate cancer risk: a nested case-control study.
- 2010
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Ingår i: Cancer Causes and Control. - : Springer Science and Business Media LLC. - 1573-7225 .- 0957-5243. ; Jul 1, s. 1635-1643
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Tidskriftsartikel (refereegranskat)abstract
- The pathogenesis of prostate cancer is unclear, although experimental evidence implicates androgens as playing an important role. Infertile men frequently suffer from some degree of hypogonadism and may hence be hypothesized to be at lower risk of developing prostate cancer than fertile men. To test this hypothesis, we conducted a case-control study nested within "the Malmö Diet and Cancer Study" cohort in Sweden, inviting 661 prostate cancer cases and 661 age-matched controls to participate. Of the 975 (74%) respondents, we excluded 84 childless men with unknown fertility status. Thus, 891 men were included, providing 445 prostate cancer cases and 446 controls. Of these, 841 (94%) men were biological fathers and 50 (6%) men were infertile. Logistic regression showed that the infertile men were at significantly lower risk of being diagnosed with prostate cancer than the fertile men (odds ratio, 0.45; 95% confidence interval, 0.25-0.83). Conditional and unconditional multivariate models, adjusting for socioeconomic, anthropometric, and health-status-related factors, provided similar estimates. We conclude that enduring male infertility is associated with a reduced prostate cancer risk, thus corroborating the theory that normal testicular function, and hence most probably sufficient steroidogenesis, is an important contributing factor to the later development of this malignancy.
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| 6. |
- Ruhayel, Yasir
(författare)
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Male Subfertility and Prostate Cancer Risk: Epidemiological and Genetic Studies
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Androgen action plays a pivotal role in male reproductive tract physiology and pathology. The androgen receptor (AR) gene harbors two codon repeat tracts: the CAG and GGN repeats, encoding corresponding amino acid sequences of variable length; the polyglutamine and polyglycine stretches, respectively. Variation in CAG repeat length had been associated with a number of andrological disorders, whereas very little was known about the GGN repeat when the work for this thesis was started. We hypothesized that variation in GGN length may modulate AR activity, and hence the individual susceptibility to male reproductive tract disorders. We also assessed the relationship between male subfertility-dependent childlessness and prostate cancer (PCa) risk in a nested case-control study to test the hypothesis that subfertile men are at lower risk of developing PCa than fertile men, since they are frequently hypogonadal secondary to testicular dysfunction. Our specific aims were to investigate: 1) whether the AR codon repeats are associated with clinical reproductive parameters, subfertility, hypospadias, or cryptorchidism; 2) whether childlessness secondary to male subfertility is associated with reduced PCa risk; and 3) the possible involvement of genetic variants in reducing PCa risk in subfertile men, including in the sex steroid signaling pathway and aryl hydrocarbon receptor (AHR) pathway, which mediates some of the effects of endocrine disrupting chemicals, and also in PCa risk genes implicated in previous genome-wide association studies. Our main findings were that: 1) GGN repeat lengths were significantly longer in men with penile hypospadias or cryptorchidism than in controls (median 24 vs. 23) and that the longer allele may be associated with superior AR function; 2) subfertile men were at reduced PCa risk compared with fertile men, OR: 0.45 (95% CI: 0.25-0.83); and 3) genes harboring variants that may play a role in reducing PCa risk in subfertile men include AHR, its partner molecule AHR nuclear translocator (ARNT), and estrogen receptor beta (ESR2), as well as a number of other genes, of which poly (ADP-ribose) polymerase 2 (PARP2) showed the most robust association. We conclude that: 1) longer GGN repeat lengths may be associated with cryptorchidism and hypospadias; 2) subfertile involuntarily childless men are at an approximately 50% lower risk of being diagnosed with PCa than are fathers of at least one biological child; 3) variants in a number of genes may play a role in linking male subfertility with reduced PCa risk through their associations with impaired reproductive function. The findings support the hypothesis that alterations in sex steroid action, potentially via interaction with the AHR-ARNT signaling pathway, may contribute to the overall reduction in PCa risk in subfertile men.
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| 7. |
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| 8. |
- Ruhayel, Yasir, et al.
(författare)
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Seasonal variation in serum concentrations of reproductive hormones and urinary excretion of 6-sulfatoxymelatonin in men living north and south of the Arctic Circle: a longitudinal study.
- 2007
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Ingår i: Clinical Endocrinology. - : Wiley. - 1365-2265 .- 0300-0664. ; 67:1, s. 85-92
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Tidskriftsartikel (refereegranskat)abstract
- bjective Seasonal variation in photoperiod or temperature may influence human reproductive biology. The present study evaluated whether seasonal changes occurred in the levels of reproductive hormones and the major melatonin metabolite, 6-sulfatoxymelatonin (aMT6s), in populations exposed to extreme variation in photoperiod and temperature. Design Two separate cohorts of Norwegian men were recruited from the general population in either of two locations: Tromso (69.5 degrees N, n = 92) or Oslo (60 degrees N, n = 112), located north and south of the Arctic Circle (66.5 degrees N), respectively. Measurements Four blood and 12-h overnight urine samples were obtained on separate occasions over a 12-month period, including during the photoperiod maximum and minimum. Serum concentrations of FSH, LH, testosterone (T), oestradiol (E-2), SHBG and the urinary excretion of aMT6s were assessed. Results Statistical analysis using generalized estimating equations indicated that LH levels were lowest during early winter in both locations (both P = 0.01). In Tromso, free T and E-2 concentrations peaked during early winter (P = 0.02 and 0.003, respectively). In Oslo, free T levels were lowest during early winter (P = 0.06) whereas E-2 levels were lowest during late summer (P < 0.001). Urinary aMT6s concentrations were lowest during early summer in Tromso and Oslo. Concentrations peaked during early winter in Tromso (P < 0.001) and during late winter in Oslo (P < 0.001). Conclusion LH levels exhibited similar changes in both locations, whereas the patterns of changes of the sex steroid concentrations differed, possibly indicating different underlying mechanisms. Excretion of aMT6s was lowest during early summer in both locations, indicating that the long natural photoperiod was sufficient to cause suppression of melatonin secretion. Whether these changes have any biological significance remains uncertain.
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