Diagnostic markers for germ cell neoplasms: from placental-like alkaline phosphatase to micro-RNAs

This concise review summarises tissue and serum markers useful for differential diagnosis of germ cell tumours (GCT), with focus on the most common testicular GCT (TGCT). GCT are characterised by phenotypic heterogeneity due to largely retained embryonic pluripotency and aberrant somatic differentiation. TGCT that occur in young men are divided into two main types, seminoma and nonseminoma, both derived from a pre-invasive germ cell neoplasia in situ (GCNIS), which originates from transformed foetal gonocytes. In severely dysgenetic gonads, a GCNIS-resembling lesion is called gonadoblastoma. GCT occur rarely in young children (infantile GCT) in whom the pathogenesis is different (no GCNIS/gonadoblastoma stage) but the histopathological features are similar to the adult GCT. The rare spermatocytic tumour of older men is derived from post-pubertal spermatogonia that clonally expand due to gain-of function mutations in survival-promoting genes (e.g. FGFR3, HRAS), thus this tumour has a different expression profile than GCNIS-derived TGCT. Clinically most informative immunohistochemical markers for GCT, except teratoma, are genes expressed in primordial germ cells/gonocytes and embryonic pluripotency-related factors, such as placental-like alkaline phosphatase (PLAP), OCT4 (POU5F1), NANOG, AP-2γ (TFAP2C) and LIN28, which are not expressed in normal adult germ cells. Some of these markers can also be used for immunocytochemistry to detect GCNIS or incipient tumours in semen samples. Gene expression in GCT is regulated in part by DNA and histone modifications, and the epigenetic profile of these tumours is characterised by genome-wide demethylation, except nonseminomas. In addition, a recently discovered mechanism of post-genomic gene expression regulation involves small non-coding RNAs, predominantly micro-RNA (miR). Testicular GCT display micro-RNA profiles similar to embryonic stem cells. Targeted miRNA-based blood tests for miR-371-3 and miR-367 clusters are currently under development and hold a great promise for the future. In some patients miR-based tests may be even more sensitive than the classical serum tumour markers, β -chorio-gonadotrophin (β-hCG), α-fetoprotein (AFP) and lactate dehydrogenase (LDH), which are currently used in the clinic. In summary, research advances have provided clinicians with a panel of molecular markers, which allow specific diagnosis of various subtypes of GCT and are very useful for early detection at the precursor stage and for monitoring of patients during the follow-up

Gene expression profiles of mouse spermatogenesis during recovery from irradiation

<p>Abstract</p> <p>Background</p> <p>Irradiation or chemotherapy that suspend normal spermatogenesis is commonly used to treat various cancers. Fortunately, spermatogenesis in many cases can be restored after such treatments but knowledge is limited about the re-initiation process. Earlier studies have described the cellular changes that happen during recovery from irradiation by means of histology. We have earlier generated gene expression profiles during induction of spermatogenesis in mouse postnatal developing testes and found a correlation between profiles and the expressing cell types. The aim of the present work was to utilize the link between expression profile and cell types to follow the cellular changes that occur during post-irradiation recovery of spermatogenesis in order to describe recovery by means of gene expression.</p> <p>Methods</p> <p>Adult mouse testes were subjected to irradiation with 1 Gy or a fractionated radiation of two times 1 Gy. Testes were sampled every third or fourth day to follow the recovery of spermatogenesis and gene expression profiles generated by means of differential display RT-PCR. In situ hybridization was in addition performed to verify cell-type specific gene expression patterns.</p> <p>Results</p> <p>Irradiation of mice testis created a gap in spermatogenesis, which was initiated by loss of A1 to B-spermatogonia and lasted for approximately 10 days. Irradiation with 2 times 1 Gy showed a more pronounced effect on germ cell elimination than with 1 Gy, but spermatogenesis was in both cases completely reconstituted 42 days after irradiation. Comparison of expression profiles indicated that the cellular reconstitution appeared equivalent to what is observed during induction of normal spermatogenesis.</p> <p>Conclusion</p> <p>The data indicates that recovery of spermatogenesis can be monitored by means of gene expression, which could aid in designing radiation treatment regimes for cancer patients leading to better restoration of spermatogenesis.</p

Beta: an experiment in funded undergraduate start up

This paper reports on an evaluation of a funded undergraduate project designed to enable student business start-up. The programme, entitled 'Beta', provides undergraduate students with £1,500 of seed-corn funding. The key objective of the project is for the participants to exit it with a viable and legal business entity through which they can start trading on completion of the course. The study adopts a case study approach and evaluates all aspects of the Beta programme, the actors involved and its processes and practices. The authors examine the development of the project and the challenges and hurdles that were identified and overcome to realize the project's goals

Dual effects of phytoestrogens result in u-shaped dose-response curves.

Endocrine disruptors can affect the endocrine system without directly interacting with receptors, for example, by interfering with the synthesis or metabolism of steroid hormones. The aromatase that converts testosterone to 17beta-estradiol is a possible target. In this paper we describe an assay that simultaneously detects aromatase inhibition and estrogenicity. The principle is similar to that of other MCF-7 estrogenicity assays, but with a fixed amount of testosterone added. The endogenous aromatase activity in MCF-7 cells converts some of the testosterone to 17beta-estradiol, which is assayed by quantifying differences in the expression level of the estrogen-induced pS2 mRNA. Potential aromatase inhibitors can be identified by a dose-dependent reduction in the pS2 mRNA expression level after exposure to testosterone and the test compound. Using this assay, we have investigated several compounds, including synthetic chemicals and phytoestrogens, for aromatase inhibition. The phytoestrogens, except genistein, were aromatase inhibitors at low concentrations (< 1 micro M) but estrogenic at higher concentrations (greater than or equal to 1 micro M), resulting in U-shaped dose-response curves. None of the tested synthetic chemicals were aromatase inhibitors. The low-dose aromatase inhibition distinguished phytoestrogens from other estrogenic compounds and may partly explain reports about antiestrogenic properties of phytoestrogens. Aromatase inhibition may play an important role in the protective effects of phytoestrogens against breast cancer

Semen quality of 1559 young men from four cities in Japan: a cross-sectional population-based study

Objectives: To provide information of semen quality among normal young Japanese men and indicate the frequency of reduced semen quality. Design: Cross-sectional, coordinated studies of Japanese young men included from university areas. The men had to be 18-24 years, and both the man and his mother had to be born in Japan. Background information was obtained from questionnaires. Standardised and quality-controlled semen analyses were performed, reproductive hormones analysed centrally and results adjusted for confounding factors. Setting: Four study centres in Japan (Kawasaki, Osaka, Kanazawa and Nagasaki). Participants: 1559 men, median age 21.1 years, included during 1999-2003. Outcome measures: Semen volume, sperm concentration, total sperm count, sperm motility, sperm morphology and reproductive hormone levels. Results: Median sperm concentration was 59 (95% CI 52 to 68) million/ml, and 9% and 31.9% had less than 15 and 40 million/ml, respectively. Median percentage of morphologically normal spermatozoa was 9.6 (8.8 to 10.3)%. Small, but statistically significant, differences were detected for both semen and reproductive hormone variables between men from the four cities. Overall, the semen values were lower than those of a reference population of 792 fertile Japanese men. Conclusions: Assuming that the investigated men were representative for young Japanese men, a significant proportion of the population had suboptimal semen quality with reduced fertility potential, and as a group they had lower semen quality than fertile men. However, the definitive role-if any-of low semen quality for subfertility and low fertility rates remain to be investigated

Experimentally-induced ‘Testicular dysgenesis syndrome’ originates in the masculinization programming window

The testicular dysgenesis syndrome (TDS) hypothesis, which proposes that common reproductive disorders of newborn and adult human males may have a common fetal origin, is largely untested. We tested this hypothesis using a rat model involving gestational exposure to dibutyl phthalate (DBP), which suppresses testosterone production by the fetal testis. We evaluated if induction of TDS via testosterone suppression is restricted to the “masculinization programming window” (MPW), as indicated by reduction in anogenital distance (AGD). We show that DBP suppresses fetal testosterone equally during and after the MPW, but only DBP exposure in the MPW causes reduced AGD, focal testicular dysgenesis, and TDS disorders (cryptorchidism, hypospadias, reduced adult testis size, and compensated adult Leydig cell failure). Focal testicular dysgenesis, reduced size of adult male reproductive organs, and TDS disorders and their severity were all strongly associated with reduced AGD. We related our findings to human TDS cases by demonstrating similar focal dysgenetic changes in testes of men with preinvasive germ cell neoplasia (GCNIS) and in testes of DBP-MPW animals. If our results are translatable to humans, they suggest that identification of potential causes of human TDS disorders should focus on exposures during a human MPW equivalent, especially if negatively associated with offspring AGD

Intrauterine exposure to mild analgesics is a risk factor for development of male reproductive disorders in human and rat

International audienceBACKGROUND: More than half of pregnant women in the Western world report intake of mild analgesics, and some of these drugs have been associated with anti-androgenic effects in animal experiments. Intrauterine exposure to anti-androgens is suspected to contribute to the recent increase in male reproductive problems, and many of the anti-androgenic compounds are like the mild analgesics potent inhibitors of prostaglandin synthesis. Therefore, it appears imperative to further investigate the potential endocrine disrupting properties of mild analgesics. METHODS: In a prospective birth cohort study, 2297 Danish and Finnish pregnant women completed a questionnaire and 491 of the Danish mothers participated in a telephone interview, reporting on their use of mild analgesics during pregnancy. The testicular position of newborns was assessed by trained paediatricians. In rats, the impact of mild analgesics on anogenital distance (AGD) after intrauterine exposure was examined together with the effect on ex vivo gestational day 14.5 testes. RESULTS: In the Danish birth cohort, the use of mild analgesics was dose-dependently associated with congenital cryptorchidism. In particular, use during the second trimester increased the risk. This risk was further increased after the simultaneous use of different analgesics. The association was not found in the Finnish birth cohort. Intrauterine exposure of rats to paracetamol led to a reduction in the AGD and mild analgesics accordingly reduced testosterone production in ex vivo fetal rat testes. CONCLUSION: There was an association between the timing and the duration of mild analgesic use during pregnancy and the risk of cryptorchidism. These findings were supported by anti-androgenic effects in rat models leading to impaired masculinization. Our results suggest that intrauterine exposure to mild analgesics is a risk factor for development of male reproductive disorders

A path forward in the debate over health impacts of endocrine disrupting chemicals

Several recent publications reflect debate on the issue of “endocrine disrupting chemicals” (EDCs), indicating that two seemingly mutually exclusive perspectives are being articulated separately and independently. Considering this, a group of scientists with expertise in basic science, medicine and risk assessment reviewed the various aspects of the debate to identify the most significant areas of dispute and to propose a path forward. We identified four areas of debate. The first is about the definitions for terms such as “endocrine disrupting chemical”, “adverse effects”, and “endocrine system”. The second is focused on elements of hormone action including “potency”, “endpoints”, “timing”, “dose” and “thresholds”. The third addresses the information needed to establish sufficient evidence of harm. Finally, the fourth focuses on the need to develop and the characteristics of transparent, systematic methods to review the EDC literature. Herein we identify areas of general consensus and propose resolutions for these four areas that would allow the field to move beyond the current and, in our opinion, ineffective debate