Dolores J. Lamb

Azoospermia in patients heterozygous for a mutation in SYCP3

BACKGROUND Many cases of male infertility are diagnosed as idiopathic, reflecting poor understanding of the molecular defects underlying the abnormality. As more gene mutations causing male infertility in mice become known, there are improving prospects that knowledge about the genetic aetiology of human male infertility can be expanded. Sycp3 encodes a component of the synaptonemal complex. A null mutation of Sycp3 in mice causes azoospermia with meiotic arrest. We tested the hypothesis that mutation of the human testis-specific SYCP3 is associated with human non-obstructive azoospermia. METHODS Human SYCP3 was isolated on the basis of homology between mouse Sycp3 cDNA and human genome sequences at the aminoacid level. Tissue-specific expression of SYCP3 was analysed by PCR of human cDNA. Samples of DNA from 19 azoospermic patients with maturation arrest and 75 normal fertile control men were screened for mutations in the SYCP3 gene by sequence analysis of the gene. The functional significance of the mutations found was analysed by a protein interaction study of the wild-type and truncated SYCP3 proteins. FINDINGS We identified in two patients a 1 bp deletion (643delA) that results in a premature stop codon and truncation of the C-terminal, coiled-coil-forming region of the SYCP3 protein. The mutant protein showed greatly reduced interaction with the wild-type protein in vitro and interfered with SYCP3 fibre formation in cultured cells. INTERPRETATION We suggest that SYCP3 has an essential meiotic function in human spermatogenesis that is compromised by the mutant protein via dominant negative interference.

Trinucleotide (CAG) repeat polymorphisms in the androgen receptor gene : molecular markers of risk for male infertility

OBJECTIVE To determine whether changes in the polymorphic trinucleotide (CAG) tract of the androgen receptor gene are associated with spermatogenic defects in patients with male infertility. DESIGN Case-control study of two ethnic groups. SETTING University referral centers for male infertility at Baylor College of Medicine, Houston, Texas, and National University Hospital, Singapore. PARTICIPANT(S) Two hundred and fifteen patients with male infertility and depressed spermatogenesis and 142 fertile controls. MAIN OUTCOME MEASURE(S) Size of androgen receptor CAG alleles according to fluorescent-labeled polymerase chain reaction and automated analysis using Genescan software (PE Biosystems Asia, Singapore), and statistical examination of its relation to clinical variables. RESULT(S) In U.S. patients, the mean androgen receptor CAG length was significantly longer in infertile patients than in fertile controls (21.95 +/- 0.31 vs. 20.72 +/- 0.52). Logistic regression showed that each unit increase in CAG length was associated with a 20% increase in the odds of being azoospermic. The odds ratio for azoospermia was sevenfold higher for patients with > or =26 CAG repeats than in those with <26 CAG repeats. Although mean CAG length in Singapore patients was longer than in the U.S. samples, long androgen receptor CAG alleles were significantly related to male infertility in both populations. CONCLUSION(S) Long (> or =26) androgen receptor CAG alleles, which are found in up to 25% of azoospermic men, are associated with male infertility and defective spermatogenesis. Conception in these men is possible with assisted reproductive technologies, as many have spermatozoa in their testes.

Determinants of serum copper, zinc and selenium in healthy subjects

Background: We have investigated the association between serum copper, zinc and selenium concentrations, dietary intake, and demographic characteristics, including individual coronary risk factors, in healthy subjects. Methods: Serum copper, zinc and selenium were measured by atomic absorption spectrometry in 189 healthy subjects. Serum glutathione peroxidase and caeruloplasmin were also determined for each subject. A previously validated food frequency questionnaire was used to estimate the dietary trace element intake. Results: Male subjects had significantly lower serum copper (P<0.001) and caeruloplasmin (P<0.001), and higher serum zinc (P<0.05) and zinc:copper ratio (P<0.001) than female subjects. Significant differences were observed in serum copper and caeruloplasmin concentrations (P<0.01) with age. Weak but significant associations between dietary trace elements and their serum concentrations were observed for zinc (r=0.18, P=0.02), copper (r=0.17, P=0.03) and selenium (r=0.19, P=0.02). Obese subjects had significantly lower serum concentrations of zinc (P<0.05). In multifactorial analysis, dietary zinc (P<0.05), serum high-density lipoprotein-cholesterol (HDL-C) (P<0.05), diastolic blood pressure (P<0.05) and age (P=0.05) emerged as major predictors of serum zinc concentrations. The corresponding predictors for serum copper were C-reactive protein (CRP) (P<0.001), serum HDL-C (P<0.001), gender (P=0.01), physical activity levels (P<0.05) and dietary copper (P<0.05). Serum selenium concentrations were predicted by serum total cholesterol (P<0.01), serum CRP concentrations (P<0.05) and dietary selenium (P<0.03). Conclusion: Serum copper, zinc and selenium concentrations are influenced by physiological conditions such as age, diet and gender. Their serum concentrations are also associated with coronary risk factors, including body mass index, levels of physical activity, serum HDL-C and CRP.

Association of Preoperative Plasma Levels of Insulin-Like Growth Factor I and Insulin-Like Growth Factor Binding Proteins-2 and -3 With Prostate Cancer Invasion, Progression, and Metastasis

PURPOSE We tested the hypothesis that preoperative plasma levels of insulin-like growth factor (IGF) binding protein (BP)-2 or IGFBP-3 would predict cancer stage and prognosis in patients undergoing radical prostatectomy. MATERIAL AND METHODS Plasma levels of IGF-I, IGFBP-2, and IGFBP-3 were measured preoperatively in 120 consecutive patients who underwent radical prostatectomy for clinically localized disease, postoperatively in 51 of these patients, in 44 healthy men, in 19 patients with metastases to regional lymph nodes, and in 10 patients with bone metastases. RESULTS Plasma IGFBP-3 levels were lowest in patients with bone metastases (P < or = .043). IGFBP-2 levels were elevated in prostate cancer patients compared with healthy subjects (P < or = .006). However, within the group of prostatectomy patients, preoperative plasma IGFBP-2 levels were lower in patients with advanced disease (P < or = .033), were inversely correlated with prostatic tumor volume (P =.037), and declined after prostate removal (P =.044). Lower preoperative IGFBP-2 and IGFBP-3 levels and biopsy Gleason score were independent predictors of biochemical progression (P =.043, P =.040, and P =.020, respectively). In patients with disease progression, preoperative plasma IGFBP-3 levels were lower in those with aggressive than in those with nonaggressive failure (P =.042). CONCLUSION Elevation of plasma IGFBP-2 levels in prostate cancer patients apparently is due to increased release directly from the prostate. For patients with clinically localized prostate cancer, preoperative plasma IGFBP-2 levels are inversely associated with biologically aggressive disease and disease progression. Preoperative plasma IGFBP-3 levels were decreased in patients with prostate cancer metastases and were an independent predictor of biochemical progression after surgery, presumably because of an association with occult metastatic disease present at the time of radical prostatectomy.

In situ end-labeling of human testicular tissue demonstrates increased apoptosis in conditions of abnormal spermatogenesis

OBJECTIVE To determine, using an in situ end-labeling technique, whether the frequency of apoptosis is increased in testis biopsy specimens that demonstrate abnormal spermatogenesis. DESIGN Immunohistochemical analysis was performed on archived paraffin-embedded testis biopsy specimens. Apoptotic indices, defined as the number of apoptotic bodies per the total number of cells or the number of Sertoli cells, were calculated after counting all the intratubular spermatogenic cells and Sertoli cells in 20 tubules. SETTING Major academic male factor infertility clinic. PATIENT(S) Forty-eight testis biopsy specimens were obtained for routine clinical purposes from 38 men with azoospermia or severe oligozoospermia. INTERVENTION(S) In situ end-labeling was performed on archived paraffin-embedded testis biopsy specimens using terminal deoxynucleotidyl transferase. MAIN OUTCOME MEASURE(S) Apoptotic indices. RESULT(S) Significantly increased apoptotic indices were observed in patients with spermatocyte arrest, spermatid arrest, and hypospermatogenesis compared with patients with normal spermatogenesis and the Sertoli cell-only pattern. CONCLUSION(S) In situ end-labeling of testis biopsy specimens from infertile men demonstrates increased apoptosis in maturation arrest and hypospermatogenesis states compared with normal spermatogenesis and the Sertoli cell-only pattern. This unique observation implicates a prominent role for this form of programmed cell death in the pathophysiology of maturation arrest and hypospermatogenesis states.

Testosterone Replacement Therapy Following Radical Prostatectomy

INTRODUCTION Controversy exists regarding testosterone replacement therapy (TRT) in men following radical prostatectomy (RP). Many clinicians are hesitant to offer patients TRT after an RP, out of concern that the increased androgen levels may promote tumor progression or recurrence from residual tumor. Recently, several small studies have demonstrated the use of TRT in men following an RP and have shown an improvement in serum testosterone levels with no increase in prostate-specific antigen (PSA) values. AIMS The aim of this article is to assess changes in PSA and testosterone values in hypogonadal patients on TRT after RP and also to evaluate the impact of pathologic Gleason grade on ultimate PSA values. METHODS All hypogonadal men who were treated with TRT by members of our department following RP were retrospectively reviewed. PSA values before RP, after RP, and after TRT were evaluated. Serum testosterone levels before and after TRT were also examined. Only patients with undetectable PSA values and negative surgical margins on pathologic specimen were offered TRT and included in the study. MAIN OUTCOME MEASURES Main outcome measures were changes in PSA and testosterone values after initiation of TRT. RESULTS Fifty-seven men, ages 53-83 years (mean 64), were identified as having initiated TRT following RP. Men received TRT for an average of 36 months following RP (range 1-136 months). Patients were followed an average of 13 months after initiation of TRT (range 1-99 months). The mean testosterone values rose from 255 ng/dL before TRT to 459 ng/dL after TRT (P < 0.001). There was no increase in PSA values after initiation of TRT and thus no patient had a biochemical PSA recurrence. CONCLUSION TRT is effective in improving testosterone levels, without increasing PSA values, in hypogonadal men who have undergone RP.

Identification of De Novo Copy Number Variants Associated with Human Disorders of Sexual Development

Disorders of sexual development (DSD), ranging in severity from genital abnormalities to complete sex reversal, are among the most common human birth defects with incidence rates reaching almost 3%. Although causative alterations in key genes controlling gonad development have been identified, the majority of DSD cases remain unexplained. To improve the diagnosis, we screened 116 children born with idiopathic DSD using a clinically validated array-based comparative genomic hybridization platform. 8951 controls without urogenital defects were used to compare with our cohort of affected patients. Clinically relevant imbalances were found in 21.5% of the analyzed patients. Most anomalies (74.2%) evaded detection by the routinely ordered karyotype and were scattered across the genome in gene-enriched subtelomeric loci. Among these defects, confirmed de novo duplication and deletion events were noted on 1p36.33, 9p24.3 and 19q12-q13.11 for ambiguous genitalia, 10p14 and Xq28 for cryptorchidism and 12p13 and 16p11.2 for hypospadias. These variants were significantly associated with genitourinary defects (P = 6.08×10−12). The causality of defects observed in 5p15.3, 9p24.3, 22q12.1 and Xq28 was supported by the presence of overlapping chromosomal rearrangements in several unrelated patients. In addition to known gonad determining genes including SRY and DMRT1, novel candidate genes such as FGFR2, KANK1, ADCY2 and ZEB2 were encompassed. The identification of risk germline rearrangements for urogenital birth defects may impact diagnosis and genetic counseling and contribute to the elucidation of the molecular mechanisms underlying the pathogenesis of human sexual development.

Androgen Receptor Gene Mutations are Rarely Associated with Isolated Penile Hypospadias

PURPOSE Hypospadias has no known single etiology but it has been linked to androgen insensitivity caused by mutations of the androgen receptor gene. The purpose of this study was to search for such mutations in cases of various degrees of isolated hypospadias to determine whether such an association exists and, if so, with any particular anatomical subgroup. MATERIALS AND METHODS Isolated deoxyribonucleic acid from the penile tissue of 40 patients undergoing reconstructive surgery was screened for mutations of the coding regions of the androgen receptor gene using single strand conformational polymorphism analysis. In cases with abnormal single strand conformational polymorphism findings sequence analysis of the deoxyribonucleic acid was performed to define the mutation. RESULTS A missense mutation of exon 2 of the androgen receptor gene was noted in 1 patient with isolated distal penile shaft hypospadias. Sequence analysis revealed that the mutation changed amino acid residue 546 from proline to serine. No abnormalities were detected in the other 39 patients. CONCLUSIONS Isolated distal shaft hypospadias is associated with mutations of the androgen receptor gene but these mutations appear to be a rare cause of hypospadias.

The use of genomics, proteomics, and metabolomics in identifying biomarkers of male infertility.

Although male factors account for approximately 50% of all infertility, the mechanisms underlying their origin are unknown. Currently, clinicians rely primarily on semen analyses to predict male reproductive potential and chart treatment success. Even when invasive procedures are performed, the causes of male factor infertility frequently remain elusive. Recently, the advent of new technologies has spurred the search for novel male infertility biomarkers, and the detection of genes, proteins, or metabolites unique to the infertile male holds much promise. The concept that a cost-effective, noninvasive, and accurate set of biomarkers can be identified to diagnose male factor infertility is tantalizing. This review focuses on the various methodologies used in the discovery of novel biomarkers along with their findings. Specific attention is paid to recent advances in the fields of genetics, proteomics, and metabolomics.

Association of Preoperative Plasma Levels of Vascular Endothelial Growth Factor and Soluble Vascular Cell Adhesion Molecule-1 With Lymph Node Status and Biochemical Progression After Radical Prostatectomy

PURPOSE Angiogenesis is a critical process for cancer progression. We tested whether elevated circulating levels of the angiogenesis-related markers vascular endothelial growth factor (VEGF) and/or soluble vascular cell adhesion molecule-1 (sVCAM-1) are associated with prostate cancer diagnosis, stage, progression, and metastasis. PATIENTS AND METHODS Plasma levels of VEGF and sVCAM-1 were measured on frozen, archival plasma obtained preoperatively from 215 consecutive patients who underwent radical prostatectomy for clinically localized disease, nine men with untreated prostate cancer metastatic to bones, and 40 healthy men without cancer. RESULTS Plasma levels of both VEGF and sVCAM-1 were highest in patients with bone metastases (P <.001). VEGF levels were higher in patients with clinically localized disease than in healthy controls (P <.001). VEGF levels were elevated in patients with biopsy and final Gleason sum > or = 7 (P =.036 and P =.020, respectively) and extraprostatic extension (P =.047). Higher preoperative VEGF was independently associated with metastases to lymph nodes (P <.001). Both VEGF and sVCAM-1 were independently associated with biochemical progression after adjustment for the effects of standard preoperative features (P =.014 and P =.039, respectively). VEGF remained independently associated with biochemical progression after adjustment for standard postoperative features (P =.019). CONCLUSION Plasma levels of VEGF increased incrementally from healthy controls to patients with clinically localized disease to patients with lymph node and skeletal metastases. Higher preoperative VEGF was independently associated with metastases to lymph nodes and biochemical progression after surgery in both pre- and postoperative models. Plasma sVCAM-1 was elevated in men with bone metastases and was associated with biochemical progression in a preoperative model.