Bi-allelic Mutations in M1AP Are a Frequent Cause of Meiotic Arrest and Severely Impaired Spermatogenesis Leading to Male Infertility.

Male infertility affects ∼7% of men, but its causes remain poorly understood. The most severe form is non-obstructive azoospermia (NOA), which is, in part, caused by an arrest at meiosis. So far, only a few validated disease-associated genes have been reported. To address this gap, we performed whole-exome sequencing in 58 men with unexplained meiotic arrest and identified the same homozygous frameshift variant c.676dup (p.Trp226LeufsTer4) in M1AP, encoding meiosis 1 associated protein, in three unrelated men. This variant most likely results in a truncated protein as shown in vitro by heterologous expression of mutant M1AP. Next, we screened four large cohorts of infertile men and identified three additional individuals carrying homozygous c.676dup and three carrying combinations of this and other likely causal variants in M1AP. Moreover, a homozygous missense variant, c.1166C>T (p.Pro389Leu), segregated with infertility in five men from a consanguineous Turkish family. The common phenotype between all affected men was NOA, but occasionally spermatids and rarely a few spermatozoa in the semen were observed. A similar phenotype has been described for mice with disruption of M1ap. Collectively, these findings demonstrate that mutations in M1AP are a relatively frequent cause of autosomal recessive severe spermatogenic failure and male infertility with strong clinical validity.

The effect of an educational animation on knowledge of testicular health and fertility of adolescents.

STUDY QUESTION: Does the provision of an educational animation, developed with young people, about testicular health and fertility impact the knowledge of these topics among adolescents? SUMMARY ANSWER: The development and provision of education on testicular health and fertility were welcomed by adolescents and associated with a significant increase in knowledge. WHAT IS KNOWN ALREADY: Young people may know less than they should about testicular health and male fertility topics. Lack of knowledge can have implications for health including late medical help-seeking for signs and symptoms of scrotal disorders, such as torsion, for which late presentation frequently results in testicular damage. STUDY DESIGN, SIZE, DURATION: A mixed methods experimental pre- and post-design was used with embedded qualitative data collection. High school students completed a pre-animation questionnaire, watched four animations on testicular health and fertility, and completed a post-animation questionnaire. Data were collected during Personal Social and Health Education lessons across a 2-week period. PARTICIPANTS/MATERIALS, SETTING, METHODS: Four animations on testicular health and fertility, informed by andrologists, academics, designers, boys, and young men, were developed. Eligible participants were boys and girls in the UK school years 8 and 9 (age 13-14 years). Participants completed a Time 1 (T1) survey (fertility knowledge, demographics) prior to watching the animations and a Time 2 (T2) survey (fertility knowledge, perceptions of the animations) immediately after the animations. Perceptions were rated on 10-point response scales (higher scores better). Participants additionally expressed in their own words positive and negative aspects of the animations. ANOVA was used to examine the effects of the animations using a 2 (time: T1, T2)×2 (gender: male, female) design on topic knowledge, perceived importance, usefulness, and style of the animations according to gender. Regression analysis examined the associations between gender, disability, class year, and knowledge at T2 while controlling for knowledge at T1. Qualitative data on perceptions of the animations were analyzed using inductive thematic analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Results showed that the animations significantly increased testicular health and fertility-related knowledge from T1 (x̄=41.84 ± 24.72) to T2 (x̄=79.15, ±15.04). Boys had significantly higher levels of knowledge compared to girls at T1 (x̄=44.74, SD = 25.16 versus x̄=37.79 ± 23.49, respectively) and T2 (x̄=80.07, SD = 15.68 versus x̄=77.89 ± 14.30, respectively) but knowledge gain from T1 to T2 was not significantly different according to gender (P = 0.11) as shown by non-significant gender×time interaction. There were no significant gender differences in the perceived usefulness and importance of the animations or liking of the style of the animations, with both genders considering the animations as useful, important, and likable. Regression analysis showed only knowledge at T1 to be significantly associated with knowledge at T2. Qualitative data showed three main themes: accessibility of important and useful information; information engagement and help-seeking behaviour; and inclusivity of information. LIMITATIONS, REASONS FOR CAUTION: This was a pre- and post-study with a sample of young people from a selected educational institution without a control group. Only short-term effects of the animations were recorded. WIDER IMPLICATIONS OF THE FINDINGS: Adolescents are interested in and learn from the provision of engaging fertility-related information. Boys and men should be considered as being a relevant target population for fertility education, not just girls and women. STUDY FUNDING/COMPETING INTEREST(S): This research was carried out in partnership with the British Fertility Society, was financially supported by an Economic and Social Research Council Impact Acceleration Award (520792) and commercial sponsorship from iMediCare Ltd, Bayer AG, Merck Group, Cryos International given to the British Fertility Society, and a financial contribution from Orchid Cancer Appeal. The authors are fully responsible for the content of the animations and this manuscript, and the views and opinions described in the publication reflect solely those of the authors. J.B. reports a grant from Merck Serono Ltd outside the submitted work. C.H., G.G., A.D., E.B., U.G., M.L, B.W., and M.H. declare no conflict of interest. K.M. reports honoraria from Bayer and Merck. A.P. reports paid consultancy for Cryos International, Cytoswim Ltd, Exceed Health, and Merck Serono in the last 2 years, but all monies have been paid to the University of Sheffield. TRIAL REGISTRATION NUMBER: N/A.

Men's perception and understanding of male-factor infertility in the UK.

Male-factor infertility is a common but stigmatised issue, and men often do not receive the emotional support and the information they need. This study sought to understand awareness of male fertility issues compared to female fertility among the UK general male public, and also what were perceived as being the optimum methods for providing support for affected men, emotionally and through information. Men feel that male infertility is not discussed by the public as much as female infertility. Lifestyle issues that affect male fertility are not well understood, and men affected by infertility desire more support, including online, from health professionals and through peer support. Health professionals, including those in public health, could offer evidence-based programmes to reduce stigma and increase public knowledge about infertility, as well as offer emotional support to men with infertility problems.

Fertility induction in hypogonadotropic hypogonadal men.

Men with hypogonadotropic hypogonadism (HH) are typically azoospermic, and yet HH is one of the few treatable forms of male infertility. Sperm induction protocols using gonadotrophins aim to replicate the natural endocrine control of spermatogenesis. Previously virilised men with adult-onset HH and normal testicular volume respond well to monotherapy in which human chorionic gonadotrophin (hCG) acts as a long-acting LH-analogue stimulating spermatogenesis. However, this approach is rarely successful for men with congenital HH (CHH) (eg, Kallmann syndrome), for whom combined gonadotrophin therapy (hCG + follicle-stimulating hormone [FSH]) is an absolute requirement to maximise fertility potential. Key baseline predictors of successful spermatogenesis-induction include prior spontaneous testicular development (ie, testicular volume [TV] > 4 mL), serum inhibin B (IB ) concentration >60 pg/mL and no history of maldescended testes (cryptorchidism).

Should we be offering fertility preservation by surgical sperm retrieval to men with Klinefelter syndrome?

Advances in surgical sperm retrieval have greatly increased the chances of men with Klinefelter syndrome achieving biological paternity. Despite this, the vast majority of attempts to achieve fertility by using extracted gametes to fertilize eggs in vitro do not result in viable pregnancies. A powerful obstacle to success lies with the natural history of seminiferous tubule and germ cell function in Klinefelter syndrome, which typically peak (and thereafter steeply decline) up to a decade before most individuals would be contemplating paternity. Herein we discuss, in relation to a real clinical case, both the exciting technical advances surgical sperm retrieval and the logistic and ethical factors that, in practice, may act to limit their successful application.

Male central hypogonadism secondary to exogenous androgens: a review of the drugs and protocols highlighted by the online community of users for prevention and/or mitigation of adverse effects.

Androgen- or anabolic steroid-induced hypogonadism (ASIH) is no longer confined to professional athletes; its prevalence amongst young men and teenagers using androgens and/or anabolic steroids (AASs) is rising fast, and those affected can experience significant symptoms. Clinicians are increasingly encountering demanding, well-informed men affected by ASIH, yet lacking authoritative information on the subject may struggle to project a credible message. In this article, we overview the methods and drugs that men use in an attempt to counteract ASIH (with a view to either preventing its onset, or reversing it once it has developed) and summarize the scientific evidence underpinning these. The main channel for obtaining these drugs is the Internet, where they can be readily sourced without a valid prescription. An Internet search using relevant terms revealed a huge number of websites providing advice on how to buy and use products to counteract ASIH. Drugs arising repeatedly in our search included human chorionic gonadotrophin (hCG), selective oestrogen receptor modulators (SERMs) and aromatase inhibitors (AIs). The quality and accuracy of the online information was variable, but review of medical literature also highlighted a lack of scientific data to guide clinical practice. It is important for clinicians to be aware of the AAS user's self-treatment strategies with regard to ASIH side-effect mitigation. By ensuring that they are well-informed, clinicians are more likely to retain the credibility and trust of AAS users, who will in turn likely be more open to engage with appropriate management.

Reproductive outcomes after surgical sperm retrieval in couples with male factor subfertility: a 10-year retrospective national cohort.

OBJECTIVE: To determine any significant differences in the reproductive outcome from intracytoplasmic sperm injection (ICSI) with surgical sperm retrieval (SSR) between cycles using fresh and cryopreserved sperm and between cycles using epididymal and testicular sperm. DESIGN: A retrospective national cohort study using data from the UK Human Fertilisation and Embryology Authority, including all ICSI cycles performed in the United Kingdom over a 10-year period. SETTING: Hospital. PATIENT(S): All nondonor ICSI cycles from 2008 to 2017 categorized by sperm source and cryopreservation status. INTERVENTION(S): Intracytoplasmic sperm injection with SSR using fresh or cryopreserved sperm and using ejaculated, testicular, and epididymal sperm. MAIN OUTCOME MEASURE(S): Live birth rate, pregnancy rate, and implantation rate. RESULT(S): We analyzed data from 214,649 ICSI cycles, including 199,818 cycles of ejaculated sperm, 5,646 cycles of epididymal sperm, and 9,185 cycles of testicular sperm. Live births rates per ICSI cycle were 28.5%, 30.6%, and 28.7% for ejaculated, epididymal, and testicular sperm cycles, respectively. Epididymal sperm cycles had a higher live birth rate than that of testicular sperm cycles (odds ratio [OR], 1.067; 95% confidence interval [CI], 1.014-1.123). This was despite a higher mean male age (42.5 vs. 40.6 years; 95% CI of difference, 1.81-1.85 years) and female age (34.3 vs. 34.0 years; 95% CI of difference, 0.32-0.34 years) in epididymal cycles than in testicular cycles. Implantation (61.2% vs. 58.0%; OR, 1.086; 95% CI, 1.041-1.133) and clinical pregnancy rates (34.3% vs. 31.3%; OR, 1.085; 95% CI, 1.039-1.132) were also higher in epididymal cycles than in testicular cycles. There were no statistically significant differences in outcomes between cycles using fresh sperm and those using cryopreserved sperm for SSR-ICSI. CONCLUSION(S): Our study indicates that reproductive outcomes of SSR-ICSI are at least comparable with those of ICSI using ejaculated sperm and does not support the preferential use of fresh sperm over cryopreserved sperm in SSR-ICSI. Births per SSR-ICSI cycle were higher for cycles using epididymal sperm than for cycles using testicular sperm; however, the differences were small, which may provide reassurance to patients undergoing these procedures. The results must be interpreted with caution because multivariable analysis was not possible because of aggregation of data.

Protocol for developing a core outcome set for male infertility research: an international consensus development study.

STUDY QUESTION: We aim to develop, disseminate and implement a minimum data set, known as a core outcome set, for future male infertility research. WHAT IS KNOWN ALREADY: Research into male infertility can be challenging to design, conduct and report. Evidence from randomized trials can be difficult to interpret and of limited ability to inform clinical practice for numerous reasons. These may include complex issues, such as variation in outcome measures and outcome reporting bias, as well as failure to consider the perspectives of men and their partners with lived experience of fertility problems. Previously, the Core Outcome Measure for Infertility Trials (COMMIT) initiative, an international consortium of researchers, healthcare professionals and people with fertility problems, has developed a core outcome set for general infertility research. Now, a bespoke core outcome set for male infertility is required to address the unique challenges pertinent to male infertility research. STUDY DESIGN SIZE DURATION: Stakeholders, including healthcare professionals, allied healthcare professionals, scientists, researchers and people with fertility problems, will be invited to participate. Formal consensus science methods will be used, including the modified Delphi method, modified Nominal Group Technique and the National Institutes of Health's consensus development conference. PARTICIPANTS/MATERIALS SETTING METHODS: An international steering group, including the relevant stakeholders outlined above, has been established to guide the development of this core outcome set. Possible core outcomes will be identified by undertaking a systematic review of randomized controlled trials evaluating potential treatments for male factor infertility. These outcomes will be entered into a modified Delphi method. Repeated reflection and re-scoring should promote convergence towards consensus outcomes, which will be prioritized during a consensus development meeting to identify a final core outcome set. We will establish standardized definitions and recommend high-quality measurement instruments for individual core outcomes. STUDY FUNDING/COMPETING INTERESTS: This work has been supported by the Urology Foundation small project award, 2021. C.L.R.B. is the recipient of a BMGF grant and received consultancy fees from Exscentia and Exceed sperm testing, paid to the University of Dundee and speaking fees or honoraria paid personally by Ferring, Copper Surgical and RBMO. S.B. received royalties from Cambridge University Press, Speaker honoraria for Obstetrical and Gynaecological Society of Singapore, Merk SMART Masterclass and Merk FERRING Forum, paid to the University of Aberdeen. Payment for leadership roles within NHS Grampian, previously paid to self, now paid to University of Aberdeen. An Honorarium is received as Editor in Chief of Human Reproduction Open. M.L.E. is an advisor to the companies Hannah and Ro. B.W.M. received an investigator grant from the NHMRC, No: GNT1176437 is a paid consultant for ObsEva and has received research funding from Ferring and Merck. R.R.H. received royalties from Elsevier for a book, consultancy fees from Glyciome, and presentation fees from GryNumber Health and Aytu Bioscience. Aytu Bioscience also funded MiOXYS systems and sensors. Attendance at Fertility 2020 and Roadshow South Africa by Ralf Henkel was funded by LogixX Pharma Ltd. R.R.H. is also Editor in Chief of Andrologia and has been an employee of LogixX Pharma Ltd. since 2020. M.S.K. is an associate editor with Human Reproduction Open. K.Mc.E. received an honoraria for lectures from Bayer and Pharmasure in 2019 and payment for an ESHRE grant review in 2019. His attendance at ESHRE 2019 and AUA 2019 was sponsored by Pharmasure and Bayer, respectively. The remaining authors declare no competing interests. TRIAL REGISTRATION NUMBER: Core Outcome Measures in Effectiveness Trials (COMET) initiative registration No: 1586. Available at www.comet-initiative.org/Studies/Details/1586. TRIAL REGISTRATION DATE: N/A. DATE OF FIRST PATIENT'S ENROLMENT: N/A.

Should the current guidelines for the treatment of varicoceles in infertile men be re-evaluated?

Male infertility is a major health burden worldwide. In the United Kingdom, the diagnostic and treatment pathway for male factor fertility is fragmented with wide variance in management and funding protocols. There is now a focus on potential overtreatment of couples with IVF and failure to treat male factors before considering assisted reproductive technology (ART). Despite this, contemporary Urological guidelines are not definitive in the indications for varicocele treatment, whilst the current National Institute for Health and Care Excellence (NICE) guidelines do not advocate surgical intervention. While controversy exists concerning the effects of varicocele treatment on natural pregnancy rates, there is growing evidence that varicocele treatment can have additional positive effects on fertility by reducing their impact on sperm DNA fragmentation and improving ART outcomes. Studies have demonstrated that azoospermic men may become oligospermic following varicocele intervention, obviating the need for surgical sperm retrieval. Sperm retrieval rates also increase following varicocele treatment in men with non-obstructive azoospermia. The contemporary literature demonstrates a clear clinical benefit for treating varicoceles in infertile men, which may be more cost-effective than proceeding to immediate ART. This review comprehensively evaluates the current indications for varicocele treatment, and it is proposed that these should be redefined in contemporary guidelines to reflect current advances in male fertility research.

Current status of fertility and family formation in men with cystic fibrosis.

Men with cystic fibrosis are nearly always infertile due to congenital bilateral absence of the vas deferens, but can undergo assisted reproduction. Ill health may influence reproductive choices. This paper reports data on fertility and family formation in CF including the use of assisted reproduction in a total cohort of 205 men (mean age 30.9, range 16.6-64.3 years) studied over a 10-year period. Overall 102 (49.5%) were single, 52 (25.7%) were married, 48 (23.3%) were in long-term heterosexual relationships, and 3 (1.5%) were in same-sex relationships. One (0.5%) was fertile naturally. In total, 30 children were born to 23 (11%) men by assisted reproduction: 4 used donor sperm and 19 had sperm retrieval and intracytoplasmic sperm injection (ICSI). Two men each adopted two children; 15 (7.3%) men were acting as step-fathers to 20 children from their partners' previous relationships. Overall 41 (20%) men had fatherhood roles. ICSI was unsuccessful in 4 men. A further 16 men were referred for fertility treatment but did not proceed. Of the 19 men having children by ICSI, 3 died leaving 4 children. Men with CF face complex decisions when considering their relationships, fertility and fatherhood.

A review of varicocele treatment and fertility outcomes.

Varicoceles are reported to be present in a significant proportion of men presenting with subfertility and are more common amongst this group than in the general population. Opinion still remains divided amongst clinicians managing male factor infertility as to whether varicoceles alter the probability of spontaneous conception and/or pregnancy and live birth rates after fertility treatment. The debate as to whether varicoceles should be treated or not has intensified in recent years. This is due to the concerns regarding the impact of varicoceles on not only conventional semen parameters, but also the potential effects that they may have at the cellular level (an increase in circulating reactive oxygen species (ROS) resulting in sperm DNA fragmentation, even when conventional semen parameters are within the normal reference ranges). It has been suggested that treating the varicocele may result in improvements in the semen parameters, the fertilization and pregnancy rates for both spontaneous pregnancy as well as following in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment. ICSI can still be used for Assisted Reproduction Treatment (ART) in the presence of suboptimal semen parameters. However, it is an invasive and expensive technique with potential adverse effects on the offspring. As far as we are aware, there are no randomized controlled trials comparing the clinical/cost effectiveness of varicocele treatment versus the immediate use of ICSI on pregnancy rates. Previous modelling exercises are old and do not take into consideration current practices and trends such as rising female age and time to pregnancy. The conflicting advice that patients sometimes receive, challenges our commitment to evidence-based practice. The only way to resolve the controversy is to undertake an appropriately powered randomized trial, assessing clinical- and cost-effectiveness and the time to pregnancy following varicocele treatment and comparing this to a no treatment group.

Applying the Adaptive Leadership Framework for Chronic Illness to understand how American and British men navigate the infertility process.

In this article, we sought to understand the adaptive challenges and work faced by men with male factor infertility. Using a prospective qualitative study in private (the United States) and academic (the United Kingdom) urology clinics, we recruited seven American and five British men with primary infertility after their urology consultation for male factor infertility between December 2015 and April 2017. Individual in-depth qualitative interviews were conducted shortly after male factor infertility urology consultation and then two additional interviews at about 3 and 6 months. We found three themes related to adaptive challenges faced during fertility treatment: avoidance (not disclosing, avoided social network), uncertainty (about ability to have a child, fertility-related information, and male factor infertility status), and affective symptoms (sadness, shock, disbelief, denial, about not achieving fatherhood, and poor outcomes). Four themes about adaptive work included focusing on goal (having clear, actionable steps; knowledge received from urologist; exhausted all options; focus on parenthood), support from partner (relationship and communication), support from health care team (provision of emotional support, increased comfort with staff over time, disclosure of knowing others with same condition), and acquired information (understanding issue, support from urologist, seeking information). We concluded that men with male factor infertility face adaptive challenges including avoidance, uncertainty, and affective symptoms. To manage during the treatment process, they use adaptive work including focusing on the goal, receiving support from their partner and health care team, and acquiring information. Although qualitative results cannot be generalized to larger populations, they might be applicable to men with male factor infertility during infertility treatment.

Male subfertility as a chronic illness: the role of adaptive challenges.

Male factor infertility (MFI) is extremely common, often with several associated chronic health conditions. Because a man's fertility assessment may be their first contact with health services, the health care team has a responsibility to act as male health advocates to ensure comprehensive care. The diagnosis of subfertility allows a broader view of these men as patients with a chronic illness who have complex health needs. Because of the associated complexity of care following evaluation, there needs to be new approach in how men affected by MFI should be managed long term. In this commentary, we propose that the Adaptive Leadership Framework model for Chronic Illness is a suitable vehicle to use for management of the MFI patient's journey towards optimized health.

The sperm donor programme over 11 years at Newcastle Fertility Centre.

The UK national sperm donor shortage is well known. We aimed to analyse the trends in various aspects of the sperm donor programme at Newcastle Fertility Centre (NFC) between 2000 and 2010. A retrospective review of the assisted conception treatments with donor sperm was performed. A decline in the numbers of donors recruited alongside a declining trend in the number of patients treated with donor sperm and donor insemination (DI) treatment cycles carried out was apparent. There was an accompanying rising trend in donor IVF cycles and in same-sex couples and single women coming for treatment. The transfer of sperm to local peripheral centres ceased during this time and an increasing number of patients imported sperm from overseas commercial sperm banks. A waiting list for treatment was set up in 2007 with a gradual increase in waiting time to 18 months in 2010. Overall, there was a significant change in the sperm donor programme at NFC with fewer donors recruited, fewer patients receiving treatment, increasing sperm import and longer waiting times for treatment over the study period.

Penile fracture.

BACKGROUND: A 23-year-old man presented with a painful penis following sexual intercourse. On examination he had a swollen, bruised penis that was tender on palpation, most markedly on the right lateral aspect. INVESTIGATIONS: Urinalysis. DIAGNOSIS: Rupture of right corpus cavernosum. MANAGEMENT: Immediate surgical repair.

Caffeic acid phenethyl ester-induced PC-3 cell apoptosis is caspase-dependent and mediated through the loss of inhibitors of apoptosis proteins.

OBJECTIVE: To investigate the effects of a novel agent, caffeic acid phethyl ester (CAPE) on nuclear factor (NF)-kappaB activation and apoptosis in the androgen-independent PC3 prostate cancer cell line. MATERIALS AND METHODS: PC-3 cells were assessed for NF-kappaB activation induced by paclitaxel and tumour necrosis factor-alpha (TNF-alpha), using a p65 enzyme-linked immunosorbent assay, with or without CAPE treatment. The corresponding apoptosis was assessed with propidium iodide DNA staining using flow cytometry. The pan-caspase inhibitor Z-VAD-FMK was used to investigate the mechanism of apoptosis. Alterations in the expression of inhibitor of apoptosis proteins (IAP), cIAP-1, cIAP-2 and XIAP, were detected using western blot analysis. RESULTS: CAPE prevented paclitaxel and TNFalpha-mediated NF-kappaB activation. Its ability to induce apoptosis in a dose-dependent manner was associated with the loss of cIAP-1, cIAP-2 and XIAP expression. Pretreatment with Z-VAD-FMK prevented CAPE-induced apoptosis and the loss of the IAPs. CONCLUSIONS: CAPE is an effective inhibitor of NF-kappaB activation in PC-3 cells, but the mechanism of apoptosis, and the corresponding loss of IAP expression, is caspase-dependent.

An antisense oligonucleotide to cIAP-1 sensitizes prostate cancer cells to fas and TNFalpha mediated apoptosis.

BACKGROUND: The inhibitors of apoptosis (IAP) proteins are a family of structurally homologous caspase inhibitors. We synthesized an antisense oligonucleotide (AO) to target a region within the BIR domain of cIAP-1 and examined its ability to facilitate apoptosis in prostate cancer cells. METHODS: We transfected the IAP AO into PC3 and DU145 cells and determined alterations in IAP expression using Western blotting. Apoptosis and viability were assessed using propidium iodide (PI) DNA incorporation with flow cytometry. Pacitaxel, caffeic acid phenethyl ester (CAPE), Fas antibody, and TNFalpha were used as 'second hit' agents in association with the AO. RESULTS: Western blotting showed a down-regulation in cIAP-1 expression and higher levels of spontaneous apoptosis in both cell types with no alteration in overall cell viability. AO sensitized PC3 cells, to Fas antibody and TNFalpha-mediated apoptosis, but not to apoptosis mediated by paclitaxel or CAPE. CONCLUSIONS: cIAP-1 down-regulation increased spontaneous apoptosis in prostate cancer cells and sensitized PC3 cells to receptor-mediated apoptosis.

Inhibitors of apoptosis proteins in prostate cancer cell lines.

BACKGROUND: The caspases are the central executioners of apoptosis. The inhibitors of apoptosis proteins (IAPs) are a family of recently described caspase inhibitors. We hypothesised that tumor resistance to apoptosis could be due in part to IAP expression. METHODS: The expression of NAIP, cIAP-1, cIAP-2, XIAP, and survivin was investigated in the prostate cancer cell lines LNCaP, PC3, and DU145. RNase protection assays and Western blotting were used to assess RNA and protein expression. Apoptotic susceptibility was determined using etoposide and assessed by propidium iodide (PI) DNA incorporation using flow cytometry. RESULTS: DU145 and PC3 cells were more resistant to apoptosis than LNCaP cells. All the IAPs were identified in the cell lines with variation in IAP expression between different cell types. Immunohistochemistry demonstrated cIAP-1 expression in PC3 cells was nuclear, while the expression of cIAP-2 and XIAP was perinuclear. Growing LNCaP cells in charcoal-stripped or androgen-supplemented medium resulted in no alteration in IAP expression. CONCLUSIONS: This study characterises the expression of IAP in three of the most commonly used prostate cancer cells. IAP may make an important contribution to apoptotic resistance in patients with prostate cancer.