Protein kinase B (Akt) blockade inhibits LH/hCG-mediated 17,20-lyase, but not 17α-hydroxylase activity of Cyp17a1 in mouse Leydig cell steroidogenesis

Androgens are produced by adrenal and gonadal cells thanks to the action of specific enzymes. We investigated the role of protein kinase B (Akt) in the modulation of Δ4 steroidogenic enzymes' activity, in the mouse Leydig tumor cell line mLTC1. Cells were treated for 0-24 h with the 3 × 50% effective concentration of human luteinizing hormone (LH) and choriogonadotropin (hCG), in the presence and in the absence of the specific Akt inhibitor 3CAI. Cell signaling analysis was performed by bioluminescence resonance energy transfer (BRET) and Western blotting, while the expression of key target genes was investigated by real-time PCR. The synthesis of progesterone, 17α-hydroxy (OH)-progesterone and testosterone was measured by immunoassay. Control experiments for cell viability and caspase 3 activation were performed as well. We found that both hormones activated cAMP and downstream effectors, such as extracellularly-regulated kinase 1/2 (Erk1/2) and cAMP response element-binding protein (Creb), as well as Akt, and the transcription of Stard1, Hsd3b1, Cyp17a1 and Hsd17b3 genes, boosting the Δ4 steroidogenic pathway. Interestingly, Akt blockade decreased selectively Cyp17a1 expression levels, inhibiting its 17,20-lyase, but not the 17-hydroxylase activity. This effect is consistent with lower Cyp17a1 affinity to 17α-OH-progesterone than progesterone. As a result, cell treatment with 3CAI resulted in 17α-OH-progesterone accumulation at 16-24 h and decreased testosterone levels after 24 h. In conclusion, in the mouse Leydig cell line mLTC1, we found substantial Akt dependence of the 17,20-lyase activity and testosterone synthesis. Our results indicate that different intracellular pathways modulate selectively the dual activity of Cyp17a1.

LH increases the response to FSH in granulosa-lutein cells from sub/poor-responder patients in vitro

STUDY QUESTION

Does LH addition to FSH in vitro recover the human primary granulosa lutein cell (hGLC) sub/poor-response?

SUMMARY ANSWER

A picomolar concentration of LH may recover the FSH-induced cAMP and progesterone production of hGLC from sub/poor-responder women.

WHAT IS KNOWN ALREADY

Clinical studies suggested that FSH and LH co-treatment may be beneficial for the ovarian response of sub/poor-responders undergoing ovarian stimulation during ART.

STUDY DESIGN, SIZE, DURATION

hGLC samples from 286 anonymous women undergoing oocyte retrieval for ART were collected from October 2017 to February 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

hGLCs from women undergoing ovarian stimulation during ART were blindly purified, cultured, genotyped and treated in vitro by increasing concentrations of FSH (nM) ±0.5 nM LH. cAMP and progesterone levels produced after 3 and 24 h, respectively, were measured. In vitro data were stratified a posteriori, according to the donors' ovarian response, into normo-, sub- and poor-responder groups and statistically compared. The effects of LH addition to FSH were compared with those obtained by FSH alone in all the groups as well.

MAIN RESULTS AND THE ROLE OF CHANCE

hGLCs from normo-responders were shown to have higher sensitivity to FSH treatment than sub-/poor-responders in vitro. Equimolar FSH concentrations induced higher cAMP (about 2.5- to 4.2-fold), and progesterone plateau levels (1.2- to 2.1-fold), in cells from normo-responder women than those from sub-/poor-responders (ANOVA; P < 0.05). The addition of LH to the cell treatment significantly increased overall FSH efficacy, indicated by cAMP and progesterone levels, within all groups (P > 0.05). Interestingly, these in vitro endpoints, collected from the normo-responder group treated with FSH alone, were similar to those obtained in the sub-/poor-responder group under FSH + LH treatment. No different allele frequencies and FSH receptor (FSHR) gene expression levels between groups were found, excluding genetics of gonadotropin and their receptors as a factor linked to the normo-, sub- and poor-response. In conclusion, FSH elicits phenotype-specific ovarian lutein cell response. Most importantly, LH addition may fill the gap between cAMP and steroid production patterns between normo- and sub/poor-responders.

LIMITATIONS, REASONS FOR CAUTION

Although the number of experimental replicates is overall high for an in vitro study, clinical trials are required to demonstrate if the endpoints evaluated herein reflect parameters of successful ART. hGLC retrieved after ovarian stimulation may not fully reproduce the response to hormones of granulosa cells from the antral follicular stage.

WIDER IMPLICATIONS OF THE FINDINGS

This in vitro assay may describe the individual response to personalize ART stimulation protocol, according to the normo-, sub- and poor-responder status. Moreover, this in vitro study supports the need to conduct optimally designed, randomized clinical trials exploring the personalized use of LH in assisted reproduction.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Merck KGaA. M.L. and C.C. are employees of Merck KGaA or of the affiliate Merck Serono SpA. Other authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Which sperm parameter limits could really guide the clinical decision in assisted reproduction?

BACKGROUND

The predictive role of sperm motility and morphology was recently detected in a large sample of more than 20000 assisted reproductive technology (ART) fresh cycles. However, the complete ART procedure consisted of both fresh and frozen-embryos transfers and only a comprehensive evaluation of the entire process could really confirm if these parameters really predict the ART success. The aim of the study was to evaluate which sperm parameter could predict the success of ART.

METHODS

A retrospective, real-world data analysis was performed, enrolling all couples attending ART from 2008 to 2021, including both fresh and frozen cycles and both in vitro fertilization (IVF) and intra-cytoplasmic sperm injection (ICSI) procedures.

RESULTS

Fresh cycles success (considering live birth rate) was predicted by female age (1.04 [1.02-1.06]), injected oocytes (0.96 [0.93-0.99]), embryo number (0.79 [0.75-0.83]) and progressive sperm motility (0.98 [0.97-0.99]). On the contrary, frozen cycle outcomes were predicted only by sperm motility (0.97 [0.95-0.99]). This prediction was confirmed in IVF but not in ICSI cycles.

CONCLUSION

Both female and male parameters predicted the ART success considering the entire path. However, frozen cycle success was predicted only by progressive sperm motility in IVF cycles, suggesting that the potential amelioration of this male parameter is relevant to improve ART success. Those couples expected to obtain the highest embryos after fertilization (low female age and better semen parameters) will have more attempts with frozen cycles and thus would benefit from a potential treatment focused to improve sperm parameters.

P-036 Analysis of semen cryopreservation in a cohort of cancer patients

Study question

To investigate the possible correlation between different types of cancer and sperm quality in patients preserving their fertility and evaluate the reproductive outcomes of patients

Summary answer

Testicular cancer was associated with lower sperm volumes (p = 0.041), lower total sperm concentration (p = 0.009) and oligozoospermia (p &lt; 0.001) compared to other cancers.

What is known already

The advancement in cancer treatments over the years frequently allowed a remission in most young patients. In males, spermatogonia are sensitive to chemotherapy and radiotherapy, causing an impairment of sperm production and competence. Moreover, up to two-thirds of patients with cancer have impaired semen parameters before any treatment but findings on whether and how specific types of malignancies can alter them remains heterogeneous. Today the advancement of Assisted Reproductive Technologies (ART) made male fertility preservation widely available, therefore counselling and sperm banking should be offered to all men in reproductive age with a diagnosis of cancer before any treatment.

Study design, size, duration

This was an observational cohort study conducted on cancer patients that underwent fertility preservation at the Center of reproductive Medicine and Surgery “P. Bertocchi” at the Department of Obstetrics and Gynecology in AUSL-IRCCS of Reggio Emilia, Italy between 2007 and 2018. The participation to the study was retrospectively proposed to all patients submitted to fertility preservation counselling from January 1st 2007 to March 28th 2018, and prospectively from March 29th 2018 to December 31st 2018.

Participants/materials, setting, methods

Semen parameters regarding volume, concentration, motility, and morphology were assessed according to the WHO criteria of 2010 in semen samples collected before any cancer treatment. Based on the macroscopic and microscopic evaluation of each sample, all those with at least cryptozoospermia were frozen. We also evaluated the reproductive outcomes of patients seeking a pregnancy with sperm frozen before cancer treatments. Semen parameters and pregnancy outcomes were compared between testicular versus other cancers.

Main results and the role of chance

During the study period, 329 patients were included with a mean age at enrollment of 32.7 ± 8.6 years. A successful cryopreservation was achieved in 94.5% of cases; the cryopreservation failed in 5.5% of cases, due to azoospermia or missed delivery samples. More than half of the cryopreservations were performed in patients affected by testicular cancer (53.3%), followed by those affected by Hodgkin (19.3%) and non-Hodgkin Lymphoma (13.5%), reflecting the increased incidence of these cancer histotypes in the age group of 20-40 years. Testicular cancer was associated with lower sperm volumes (p = 0.041) and lower total sperm concentration (p = 0.009) compared to other cancers. No difference was observed about sperm motility and morphology, while oligozoospermia was significantly more frequent in men with testicular cancer (p &lt; 0.001). In the cohort, the 8.4% of patients thawed their samples; the usage rate and the embryo transfer rate were significantly higher (p = 0.04) among those with a testicular cancer, while pregnancy and livebirth rates did not differ between the two groups.

Limitations, reasons for caution

Relevant limitations of the study included: the absence of a follow-up on fertility status after cancer remission, missing data about spontaneous pregnancies, and information on the seminal status of each patient before cancer diagnosis, precluding any etiopathological consideration between neoplastic pathology and seminal parameters.

Wider implications of the findings

Male fertility preservation is feasible, easy to be performed, non-invasive and does not delay cancer treatments. Men affected by testicular cancer had worse semen parameters at cryopreservation, but pregnancy and livebirth rates were similar to those achieved by men with other cancers and similar to those achieved with fresh sperm.

Trial registration number

not applicable

P-585 The (decision) tree of fertility: an innovative decision-making algorithm in assisted reproduction technique

Study question

To develop a decisional algorithm able to predict pregnancy and live birth rates after controlled ovarian stimulation (COS), helping to decide whether to perform oocytes pick-up.

Summary answer

A systematic approach allows to identify ovarian follicles, female age and sperm motility as predictors of ART outcome, reducing the socio-economic burden of ART failure

What is known already

The physician needs to estimate a priori the female response after the COS phase, leaving an extreme variability in the proposed therapeutic regimens. Indeed, the most cost-effective ART management in terms of pregnancy and live birth rates is still far to be achieve and the clinical application of predictive models is still scanty, considering their limited predictive ability. A predictive model able to estimate the chances of success in the time point after ovarian stimulation and before the pick-up could guide the decision to prosecute or not the ongoing ART path

Study design, size, duration

A single centre, retrospective analysis of data was carried out, considering all couples attending the Fertility Centre of the Department of Obstetrics and Gynaecology of Reggio Emilia (Italy). All consecutive ART cycles performed from 1998 to December 2020 were retrospectively extracted and couples fulfilling inclusion criteria were included in the final dataset with final included 12,275 ART cycles. The strong ART outcomes were considered, i.e. biochemical and clinical pregnancy and live birth rates.

Participants/materials, setting, methods

Couple with both partners older than 18 years and attending fresh ART cycles are available are included in the study. The ART procedure was evaluated collecting several variables, considering male parameters, COS approach and variables of COS response. The fertilization rate was calculated as the ratio between the number of fertilized oocytes and the number of either injected (ICSI method) or inseminated (IVF cycles) oocytes.

Main results and the role of chance

The final database included 12,275 ART cycles, consisting of 7,826 ICSI (63.8%) and 4,449 IVF (36.2%) procedures. The 87.5% of the entire cohort (10,375 couples) were treated for primary couple infertility. Linear regression analyses highlighted a relationship between number of ovarian follicles &gt;17 mm detected at ultrasound before pick-up (OF17), embryos number and fertilization rate, and biochemical and clinical pregnancy rates (p &lt; 0.001), but not live birth rate. Decisional Tree (DT) were created for biochemical pregnancy (statistical power–SP:80.8%), clinical pregnancy (SP:85.4%) and live birth (SP:87.2%). Thresholds for OF17 entered in all DT, while sperm motility entered the biochemical pregnancy’s model, and female age entered the clinical pregnancy and live birth DT. In case of OF17&lt;3, the chance of conceiving was &lt;6% for all DT. Logistic regression analyses confirmed the relationship between strong ART outcomes and those variables detected before pick-up. Interestingly, these connections appeared only when pregnancy rates were considered, suggesting that the classical statistical approach is not able to overcome the higher number of biases influencing live birth rates. In the biochemical pregnancy decision tree, alongside to OF17, sperm motility entered the model introducing the threshold of 34%.

Limitations, reasons for caution

In the study were included only those cycles in which all ART variables were available. During the long interval of data collection, ART technologies evolved, as well as the regulatory rules for ART access. This data heterogeneity over the years could mitigate the reliability of results.

Wider implications of the findings

The identification of three decision trees helping the clinician to decide whether or not to perform oocytes pick-up, continuing the ongoing ART path. In mathematical models, three predictors of ART success at a very early stage emerged, such as ovarian follicles higher than 17 mm, sperm motility and female age.

Trial registration number

not applicable

P-032 Sperm parameters can predict the success of assisted reproductive technology. Single-center and retrospective analysis of assisted reproductive technology cycles from 1992 to 2020

Study question

Male parameters are largely underestimated in assisted reproductive technology (ART) success, so it was evaluated whether conventional semen parameters could predict assisted reproductive technology success

Summary answer

Sperm motility plays a role in predicting in vitro fertilization (IVF) success, while sperm morphology is the relevant parameter in intracytoplasmic sperm injection (ICSI) cycles.

What is known already

The detection of predictive markers would be very useful to choose the ART type and usually the male counterpart was relegated to a secondary role. Obviously, no convincing evidence that ART outcomes may be dependent on sperm parameters exists. The variation over the years of the reference values in semen analysis, together with the poor inter-laboratory standardization of sperm assessment, contributes to this very complex scenario. It remains undeniable that identifying thresholds of seminal parameters with prognostic significance in terms of pregnancy rate would have a considerable clinical impact in the assisted reproduction field.

Study design, size, duration

A single-center, retrospective, observational study was carried out including couples attending the Santa Maria Nuova Hospital-IRCCS of Reggio Emilia for infertility between January 1992 and December 2020. Only fresh ART cycles performed in a single third-level fertility center were considered for this study with a total of 22,013 cycles. Fertilization rate was the primary end-point, representing a parameter immediately dependent on male contribution. Pregnancy and live birth rates were considered in relation to semen variables.

Participants/materials, setting, methods

Both partners were aged over 18 years and satisfied national criteria to access ART procedures. The studies considering common sperm parameters obtained by conventional semen analysis, that is, sperm number, motility, and morphology. Semen analyses were performed according to the World Health Organization (WHO) manual available at the time of the ART cycle. Ovarian stimulation was performed applying different hormone stimulating protocols and ART approach used are IVF or the ICSI.

Main results and the role of chance

Considering the entire ART cohort, 5819 cycles were IVF (26.4%) and 16,194 were ICSI (73.6%). Considering strong ART outcomes, the overall pregnancy rate was 20.4% (4,368 cycles) for biochemical and 20.2% (4,314 cycles) for clinical pregnancies, respectively. Among the latter, the overall live birth rate was 63.3%. Interestingly, both biochemical (20.8% vs. 19.1%, p &lt; 0.001) and clinical (20.7% vs. 18.5%, p &lt; 0.001) pregnancy rates were significantly higher in ICSI than IVF cycles. On the contrary, the live birth rate was not significantly different between ART methodologies (64.0% in ICSI vs. 60.9% in IVF, p = 0.074). Only 610 cycles (2.8%) were interrupted since no oocytes were retrieved after gonadotropins stimulation. Considering only cycles with oocytes retrieved, the fertilization rate was significantly higher in ICSI (42.4±39.7%) compared to IVF cycles (38.4±49.2%) (F = 27.343, p &lt; 0.001). In IVF setting, both progressive motility (p = 0.012) and motility after capacitation (p = 0.002) significantly predicted the fertilization rate (statistical accuracy = 71.1%). Sperm motilities also predicted pregnancy (p &lt; 0.001) and live birth (p = 0.001) rates. In ICSI, sperm morphology predicted fertilization rate (p = 0.001, statistical accuracy = 90.3%).

Limitations, reasons for caution

These results, although statistically significant, show confidence intervals at the limits of significance. Therefore, this data must be carefully considered. From entering the ART path to its outcome, the variables encountered are numerous. The identification of a single parameter that influences, slightly, the final outcome, indicates a considerable clinical weight.

Wider implications of the findings

Interestingly, sperm motility plays a role in predicting in vitro fertilization success, while sperm morphology is the relevant parameter in ICSI. These parameters may be considered reliable tools to measure the male role on ART outcomes, potentially impacting the clinical management of infertile couples.

Trial registration number

not applicable

Semen cryopreservation in men undergoing cancer treatment: a ten-year study

BACKGROUND

The advancement of Assisted Reproductive Technologies and the improvement in sperm freezing made male fertility preservation widely available. This study aims to evaluate the impact of cancer diseases on semen parameters before cryopreservation and the reproductive outcomes of patients who have thawed their semen samples.

METHODS

An observational, cohort study was conducted on cancer patients submitted to fertility preservation in AUSL-IRCCS of Reggio Emilia between 2007 and 2018. Semen samples were collected before cancer treatments, analysed and frozen by rapid freezing. On request, these samples were thawed for Assisted Reproductive Technologies procedures. Semen parameters were compared between testicular versus other cancers.

RESULTS

we included 329 patients with a successful cryopreservation in 94.5% of cases. Testicular cancer was associated with lower sperm volumes (p=0.041) and lower total sperm concentration (p=0.009) compared to other cancers. No difference was observed about sperm motility and morphology, while oligozoospermia was significantly more frequent in men with testicular cancer (p<0.001). In our cohort, the 8.4% of patients thawed their samples; the usage rate and the embryo transfer rate were significantly higher (p<0.05) among those with a testicular cancer, while pregnancy and livebirth rates did not differ.

CONCLUSIONS

male fertility preservation is feasible, easy to be performed, non-invasive and does not delay cancer treatments. Men affected by testicular cancer had worse semen parameters at cryopreservation but pregnancy and livebirth rates were similar to those achieved by men with other cancers and similar to those achieved with fresh sperm.

The (decision) tree of fertility: an innovative decision-making algorithm in assisted reproduction technique

PURPOSE

Several mathematical models have been developed to estimate individualized chances of assisted reproduction techniques (ART) success, although with limited clinical application. Our study aimed to develop a decisional algorithm able to predict pregnancy and live birth rates after controlled ovarian stimulation (COS) phase, helping the physician to decide whether to perform oocytes pick-up continuing the ongoing ART path.

METHODS

A single-center retrospective analysis of real-world data was carried out including all fresh ART cycles performed in 1998-2020. Baseline characteristics, ART parameters and biochemical/clinical pregnancies and live birth rates were collected. A seven-steps systematic approach for model development, combining linear regression analyses and decision trees (DT), was applied for biochemical, clinical pregnancy, and live birth rates.

RESULTS

Of fresh ART cycles, 12,275 were included. Linear regression analyses highlighted a relationship between number of ovarian follicles > 17 mm detected at ultrasound before pick-up (OF17), embryos number and fertilization rate, and biochemical and clinical pregnancy rates (p < 0.001), but not live birth rate. DT were created for biochemical pregnancy (statistical power-SP:80.8%), clinical pregnancy (SP:85.4%), and live birth (SP:87.2%). Thresholds for OF17 entered in all DT, while sperm motility entered the biochemical pregnancy's model, and female age entered the clinical pregnancy and live birth DT. In case of OF17 < 3, the chance of conceiving was < 6% for all DT.

CONCLUSION

A systematic approach allows to identify OF17, female age, and sperm motility as pre-retrieval predictors of ART outcome, possibly reducing the socio-economic burden of ART failure, allowing the clinician to perform or not the oocytes pick-up.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review (Part 6): Correlation of PD-L1 Expression with the Status of Mismatch Repair System, BRCA, PTEN, and Other Genes

Pembrolizumab (anti-PD-1) is allowed in selected metastatic castration-resistant prostate cancer (PC) patients showing microsatellite instability/mismatch repair system deficiency (MSI-H/dMMR). BRCA1/2 loss-of-function is linked to hereditary PCs and homologous recombination DNA-repair system deficiency: poly-ADP-ribose-polymerase inhibitors can be administered to BRCA-mutated PC patients. Recently, docetaxel-refractory metastatic castration-resistant PC patients with BRCA1/2 or ATM somatic mutations had higher response rates to pembrolizumab. PTEN regulates cell cycle/proliferation/apoptosis through pathways including the AKT/mTOR, which upregulates PD-L1 expression in PC. Our systematic literature review (PRISMA guidelines) investigated the potential correlations between PD-L1 and MMR/MSI/BRCA/PTEN statuses in PC, discussing few other relevant genes. Excluding selection biases, 74/677 (11%) PCs showed dMMR/MSI; 8/67 (12%) of dMMR/MSI cases were PD-L1+. dMMR-PCs included ductal (3%) and acinar (14%) PCs (all cases tested for MSI were acinar-PCs). In total, 15/39 (39%) PCs harbored BRCA1/2 aberrations: limited data are available for PD-L1 expression in these patients. 13/137 (10%) PTEN- PCs were PD-L1+; 10/29 (35%) PD-L1+ PCs showed PTEN negativity. SPOP mutations may increase PD-L1 levels, while the potential correlation between PD-L1 and ERG expression in PC should be clarified. Further research should verify how the efficacy of PD-1 inhibitors in metastatic castration-resistant PCs is related to dMMR/MSI, DNA-damage repair genes defects, or PD-L1 expression.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 7: PD-L1 Expression in Liquid Biopsy

Liquid biopsy is an accessible, non-invasive diagnostic tool for advanced prostate cancer (PC) patients, potentially representing a real-time monitoring test for tumor evolution and response to treatment through the analysis of circulating tumor cells (CTCs) and exosomes. We performed a systematic literature review (PRISMA guidelines) to describe the current knowledge about PD-L1 expression in liquid biopsies of PC patients: 101/159 (64%) cases revealed a variable number of PD-L1+ CTCs. Outcome correlations should be investigated in larger series. Nuclear PD-L1 expression by CTCs was occasionally associated with worse prognosis. Treatment (abiraterone, enzalutamide, radiotherapy, checkpoint-inhibitors) influenced PD-L1+ CTC levels. Discordance in PD-L1 status was detected between primary vs. metastatic PC tissue biopsies and CTCs vs. corresponding tumor tissues. PD-L1 is also released by PC cells through soluble exosomes, which could inhibit the T cell function, causing immune evasion. PD-L1+ PC-CTC monitoring and genomic profiling may better characterize the ongoing aggressive PC forms compared to PD-L1 evaluation on primary tumor biopsies/prostatectomy specimens (sometimes sampled a long time before recurrence/progression). Myeloid-derived suppressor cells and dendritic cells (DCs), which may have immune-suppressive effects in tumor microenvironment, have been found in PC patients circulation, sometimes expressing PD-L1. Occasionally, their levels correlated to clinical outcome. Enzalutamide-progressing castration-resistant PC patients revealed increased PD-1+ T cells and circulating PD-L1/2+ DCs.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 5: Epigenetic Regulation of PD-L1

Epigenetic alterations (including DNA methylation or miRNAs) influence oncogene/oncosuppressor gene expression without changing the DNA sequence. Prostate cancer (PC) displays a complex genetic and epigenetic regulation of cell-growth pathways and tumor progression. We performed a systematic literature review (following PRISMA guidelines) focused on the epigenetic regulation of PD-L1 expression in PC. In PC cell lines, CpG island methylation of the CD274 promoter negatively regulated PD-L1 expression. Histone modifiers also influence the PD-L1 transcription rate: the deletion or silencing of the histone modifiers MLL3/MML1 can positively regulate PD-L1 expression. Epigenetic drugs (EDs) may be promising in reprogramming tumor cells, reversing epigenetic modifications, and cancer immune evasion. EDs promoting a chromatin-inactive transcriptional state (such as bromodomain or p300/CBP inhibitors) downregulated PD-L1, while EDs favoring a chromatin-active state (i.e., histone deacetylase inhibitors) increased PD-L1 expression. miRNAs can regulate PD-L1 at a post-transcriptional level. miR-195/miR-16 were negatively associated with PD-L1 expression and positively correlated to longer biochemical recurrence-free survival; they also enhanced the radiotherapy efficacy in PC cell lines. miR-197 and miR-200a-c positively correlated to PD-L1 mRNA levels and inversely correlated to the methylation of PD-L1 promoter in a large series. miR-570, miR-34a and miR-513 may also be involved in epigenetic regulation.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 3: PD-L1, Intracellular Signaling Pathways and Tumor Microenvironment

The tumor microenvironment (TME) includes immune (T, B, NK, dendritic), stromal, mesenchymal, endothelial, adipocytic cells, extracellular matrix, and cytokines/chemokines/soluble factors regulating various intracellular signaling pathways (ISP) in tumor cells. TME influences the survival/progression of prostate cancer (PC), enabling tumor cell immune-evasion also through the activation of the PD-1/PD-L1 axis. We have performed a systematic literature review according to the PRISMA guidelines, to investigate how the PD-1/PD-L1 pathway is influenced by TME and ISPs. Tumor immune-escape mechanisms include suppression/exhaustion of tumor infiltrating cytotoxic T lymphocytes, inhibition of tumor suppressive NK cells, increase in immune-suppressive immune cells (regulatory T, M2 macrophagic, myeloid-derived suppressor, dendritic, stromal, and adipocytic cells). IFN-γ (the most investigated factor), TGF-β, TNF-α, IL-6, IL-17, IL-15, IL-27, complement factor C5a, and other soluble molecules secreted by TME components (and sometimes increased in patients' serum), as well as and hypoxia, influenced the regulation of PD-L1. Experimental studies using human and mouse PC cell lines (derived from either androgen-sensitive or androgen-resistant tumors) revealed that the intracellular ERK/MEK, Akt-mTOR, NF-kB, WNT and JAK/STAT pathways were involved in PD-L1 upregulation in PC. Blocking the PD-1/PD-L1 signaling by using immunotherapy drugs can prevent tumor immune-escape, increasing the anti-tumor activity of immune cells.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 1: Focus on Immunohistochemical Results with Discussion of Pre-Analytical and Interpretation Variables

Immunotherapy targeting the PD-1-PD-L1 axis yielded good results in treating different immunologically ''hot'' tumors. A phase II study revealed good therapeutic activity of pembrolizumab in selected prostatic carcinoma (PC)-patients. We performed a systematic literature review (PRISMA guidelines), which analyzes the immunohistochemical expression of PD-L1 in human PC samples and highlights the pre-analytical and interpretation variables. Interestingly, 29% acinar PCs, 7% ductal PCs, and 46% neuroendocrine carcinomas/tumors were PD-L1+ on immunohistochemistry. Different scoring methods or cut-off criteria were applied on variable specimen-types, evaluating tumors showing different clinic-pathologic features. The positivity rate of different PD-L1 antibody clones in tumor cells ranged from 3% (SP142) to 50% (ABM4E54), excluding the single case tested for RM-320. The most tested clone was E1L3N, followed by 22C3 (most used for pembrolizumab eligibility), SP263, SP142, and 28-8, which gave the positivity rates of 35%, 11-41% (depending on different scoring systems), 6%, 3%, and 15%, respectively. Other clones were tested in <200 cases. The PD-L1 positivity rate was usually higher in tumors than benign tissues. It was higher in non-tissue microarray specimens (41-50% vs. 15%), as PC cells frequently showed heterogenous or focal PD-L1-staining. PD-L1 was expressed by immune or stromal cells in 12% and 69% cases, respectively. Tumor heterogeneity, inter-institutional preanalytics, and inter-observer interpretation variability may account for result biases.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 4: Experimental Treatments in Pre-Clinical Studies (Cell Lines and Mouse Models)

In prostate cancer (PC), the PD-1/PD-L1 axis regulates various signaling pathways and it is influenced by extracellular factors. Pre-clinical experimental studies investigating the effects of various treatments (alone or combined) may discover how to overcome the immunotherapy-resistance in PC-patients. We performed a systematic literature review (PRISMA guidelines) to delineate the landscape of pre-clinical studies (including cell lines and mouse models) that tested treatments with effects on PD-L1 signaling in PC. NF-kB, MEK, JAK, or STAT inhibitors on human/mouse, primary/metastatic PC-cell lines variably down-modulated PD-L1-expression, reducing chemoresistance and tumor cell migration. If PC-cells were co-cultured with NK, CD8+ T-cells or CAR-T cells, the immune cell cytotoxicity increased when PD-L1 was downregulated (opposite effects for PD-L1 upregulation). In mouse models, radiotherapy, CDK4/6-inhibitors, and RB deletion induced PD-L1-upregulation, causing PC-immune-evasion. Epigenetic drugs may reduce PD-L1 expression. In some PC experimental models, blocking only the PD-1/PD-L1 pathway had limited efficacy in reducing the tumor growth. Anti-tumor effects could be increased by combining the PD-1/PD-L1 blockade with other approaches (inhibitors of tyrosine kinase, PI3K/mTOR or JAK/STAT3 pathways, p300/CBP; anti-RANKL and/or anti-CTLA-4 antibodies; cytokines; nitroxoline; DNA/cell vaccines; radiotherapy/Radium-223).

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 2: Clinic-Pathologic Correlations

Many studies have investigated the potential prognostic and predictive role of PD-L1 in prostatic carcinoma (PC). We performed a systematic literature review (PRISMA guidelines) to critically evaluate human tissue-based studies (immunohistochemistry, molecular analysis, etc.), experimental research (cell lines, mouse models), and clinical trials. Despite some controversial results and study limitations, PD-L1 expression by tumor cells may be related to clinic-pathologic features of adverse outcome, including advanced tumor stage (high pT, presence of lymph node, and distant metastases), positivity of surgical margins, high Grade Group, and castration resistance. Different PD-L1 positivity rates may be observed in matched primary PCs and various metastatic sites of the same patients. Over-fixation, type/duration of decalcification, and PD-L1 antibody clone may influence the immunohistochemical analysis of PD-L1 on bone metastases. PD-L1 seemed expressed more frequently by castration-resistant PCs (49%) as compared to hormone-sensitive PCs (17%). Some series found that PD-L1 positivity was associated with decreased time to castration resistance. Treatment with ipilimumab, cyclophosphamide/GVAX/degarelix, or degarelix alone may increase PD-L1 expression. Correlation of PD-L1 positivity with overall survival and outcomes related to tumor recurrence were rarely investigated; the few analyzed series produced conflicting results and sometimes showed limitations. Further studies are required. The testing and scoring of PD-L1 should be standardized.

Are sperm parameters able to predict the success of assisted reproductive technology? A retrospective analysis of over 22,000 assisted reproductive technology cycles

Background

An explosive increase in couples attending assisted reproductive technology has been recently observed, despite an overall success rate of about 20%–30%. Considering the assisted reproductive technology‐related economic and psycho‐social costs, the improvement of these percentages is extremely relevant. However, in the identification of predictive markers of assisted reproductive technology success, male parameters are largely underestimated so far.

Study design

Retrospective, observational study.

Objectives

To evaluate whether conventional semen parameters could predict assisted reproductive technology success.

Materials and methods

All couples attending a single third‐level fertility center from 1992 to 2020 were retrospectively enrolled, collecting all semen and assisted reproductive technology parameters of fresh cycles. Fertilization rate was the primary end‐point, representing a parameter immediately dependent on male contribution. Pregnancy and live birth rates were considered in relation to semen variables. Statistical analyses were performed using the parameters obtained according to the World Health Organization manual editions used for semen analysis.

Results

Note that, 22,013 in vitro fertilization and intracytoplasmic sperm injection cycles were considered. Overall, fertilization rate was significantly lower in patients with abnormal semen parameters compared to normozoospermic men, irrespective of the World Health Organization manual edition. In the in vitro fertilization setting, both progressive motility (p = 0.012) and motility after capacitation (p = 0.002) significantly predicted the fertilization rate (statistical accuracy = 71.1%). Sperm motilities also predicted pregnancy (p < 0.001) and live birth (p = 0.001) rates. In intracytoplasmic sperm injection cycles, sperm morphology predicted fertilization rate (p = 0.001, statistical accuracy = 90.3%). Sperm morphology significantly predicted both pregnancy (p < 0.001) and live birth (p < 0.001) rates and a cut‐off of 5.5% was identified as a threshold to predict clinical pregnancy (area under the curve = 0.811, p < 0.001).

Discussion

Interestingly, sperm motility plays a role in predicting in vitro fertilization success, while sperm morphology is the relevant parameter in intracytoplasmic sperm injection cycles. These parameters may be considered reliable tools to measure the male role on ART outcomes, potentially impacting the clinical management of infertile couples.

P–735 Spontaneous pregnancies among infertile couples during assisted reproduction lockdown for COVID–19 pandemic

Study question

Evaluate the population attending Assisted reproductive techniques (ART) who have suffered the interruption of fertilization paths because of the SARS-CoV–2 italian national lockdown declared under goverment provision.

Summary answer

The research show that some infertile couples candidate to ART paths obtained a spontaneous pregnancy during the lockdown due to SARS-CoV–2 pandemic.

What is known already

The real impact of psychological stress on couple infertility in terms of pregnancies obtained is largely under-investigated in the literature and the potential low frequency of sexual activity is usually poorly considered in the management of couple infertility and its role on pregnancies failure is unclear, but probably underestimated. Moreover, the worldwide spread of the SARS-CoV–2 infection has profoundly affected all aspects of human life, with tangible consequences in several contexts, including reproduction. This allowed to highlight the interrelation between psychological distress and reproductive medicine are still conflicting.

Study design, size, duration

This is a study conducted at the Fertility Centre of the Department of Obstetrics and Gynaecology of Reggio Emilia (Italy), that evaluated the conception ability of couples who suffered the postponement of ART cycles during the SARS-CoV–2 pandemic. In particular, we collected anamnestic, anthropometrical and demographic data of those women attending ART straddling the lockdown period, from March 2020 to April 2020.

Participants/materials, setting, methods

The study evaluated couples attending ART, who had an interruption of the fertilization paths due to the SARS-CoV–2 pandemic. The variables as women age, BMI, duration of infertility, number of sexual intercourses per week and infertility aetiology were considered in a multivariate logistic analysis. The statistical analysis was performed setting pregnancy (categorical data) as the dependent variable, and all other available data as either covariates or cofactors.

Main results and the role of chance

Among the 431 couples recalled to reschedule ART cycles 34 couples (7.9%) obtained a spontaneous pregnancy during the COVID–19 lockdown. The statistical analysis for the 431 couples recalled showed that average duration of couple infertility was 3.5 ± 2.8 years, while an exclusively female causal factor was observed in the 23.7% of cases (102 couples), an exclusively male one in the 32.7% (141 couples), a coexistence of male/female factor in the 18.6% (80 couples), and an idiopathic form in the 25.1% (108 couples). The 34 couples obtained a spontaneous pregnancy presented a female infertility factor in the 26.5% of cases (9 couples), a male factor in the 29.4% (10 couples), a male/female factor in the 11.8% (4 couples), and idiopathic infertility in the 32.4% (11 couples). The male factor of infertility was not evaluated in all couples, thus this definition came from the anamnestic evaluation of the couple. In a multivariate logistic analysis we highlighted that the infertility history duration and the sexual intercourses frequency were significantly related to pregnancy (F = 4.8, degrees of freedom=1, p = 0.030 and F = 81.6, degrees of freedom=1, p &lt; 0.001, respectively).

Limitations, reasons for caution

Despite the short observation period (two months of italian national lockdown declared under goverment provision), the large sample size of women evaluated attending to a single ART centre constitutes a point of strength of our study. However, the absence of a control group represents the most important limit.

Wider implications of the findings: In conclusion, the lockdown allowed to increase the knowledge about under-explored causes of idiopathic infertility: the frequency of sexual intercourses. This aspect in reproductive medicine could help to identify those couples able to conceive spontaneously, avoiding unnecessary over-treatment, and to correctly apply ART to those couples who really need it.

Trial registration number

none

O-226 The microscopic se men improvement after surgical varicocele repair

Study question

Evaluation of the effect of varicocele correction on conventional and microscopic seminal parameters and evaluation of which factors might predict sperm improvement after surgical treatment.

Summary answer

The detailed morphologic sperm evaluation has been identified as a novel parameter expressing the post-surgical semen amelioration after varicocelectomy.

What is known already

Generally, varicocele develops during puberty and occurs more often on the left side for anatomic reasons. However, its diagnosis is commonly delayed, especially in asymptomatic cases, until the man consults an andrologist for couple infertility. A causative relationship between varicocele and impairment of semen quality has been largely investigated in the context of male infertility. Despite the florid literature available on this topic, the clinical benefit in terms of semen quality improvement after varicocele surgical repair remains controversial.

Study design, size, duration

An observational, retrospective clinical trial was carried out including patients undergoing surgical treatment for varicocele at the Day Surgery of the Urology Operative Unit of the Santa Maria Nuova Hospital-IRCCS of Reggio Emilia from September 2011 to March 2020. Primary outcome was the detailed morphologic microscopic sperm evaluation. Secondary outcomes were conventional semen analyses. Each patient was considered two times (before and after the surgery) and evaluated by both physical examination and ultrasonography.

Participants/materials, setting, methods

The inclusion criteria considered the patients with diagnosis of varicocele at ultrasound examination, attending surgical resolution and with at semen analyses before and after the surgery, were excluded patients with diagnosis of varicocele without surgical indication, and/or semen analyses performed only before or only after the surgery. In the statistical analysis a logistic multivariate regression analysis was performed in order to evaluate the change before and after surgery.

Main results and the role of chance

The post-surgical semen analysis was performed after a mean of 183.7 + 112.5 days since the surgery for a total of 121 males (mean age 24.6 + 4.1 years) enrolled. The surgical treatment leads to a significant increase in sperm concentration (p = 0.015) and percentage of progressive and total motility (p = 0.022 and p = 0.039, respectively), with a significant decrease in the percentage of immobile sperms (p = 0.013). In particular, semen concentration improved in 71.7% of patients (p = 0.010). Considering the detailed morphologic microscopic evaluation, a significant improvement was detected: head abnormalities showed a significant reduction, considering microcephaly (3.3 + 3.6 versus 2.2 + 2.9%, p = 0.015), macrocephaly (1.4 + 0.6 versus 1.2 + 0.9%, p = 0.043) and cytoplasmic appendix (1.4 + 0.8 versus 0.9 + 1.2%, p = 0.041). Moreover, surgery led to a significant reduction of tails abnormalities, considering absence (0.6 +2.3 versus 0.1 + 0.7, p = 0.048) and coiled tail (5.2 + 1.5 versus 6.6 + 2.0, p = 0.037). Thus, surgical varicocele resolution leads to a significant improvement in specific morphological semen parameters. The multivariate logistic analysis identified the ultrasound varicocele degree before surgery as a main predictor of the sperm concentration improvement (p = 0.016). The semen parameters improvement was higher for varicocele of I and II degree (p = 0.008).

Limitations, reasons for caution

The retrospective study design precluded from carrying out a case-control study to compare the surgical techniques. Moreover, the study design limited the availability of patients’ clinical data in order to performed a more comprehensive predictive analysis.

Wider implications of the findings

Using a complex statistical approach, it emerged that the greatest improvement in semen quality was obtained in case of mild varicocele, increasing the knowledge on the therapeutic potential of surgery. This result has clinical implications, since it could help to select those patients ‘to treat or not to treat’.

Trial registration number

none

Improvement of sperm morphology after surgical varicocele repair

Background

A causative relationship between varicocele and impairment of semen quality has been largely investigated in the context of male infertility, although its clinical benefit remains controversial.

Objective

To investigate the effect of varicocele correction on detailed morphologic microscopic semen parameters in a large homogeneous cohort of patients and to evaluate which factors could predict semen improvement after the surgical treatment.

Materials and methods

An observational, retrospective cohort study was carried out including all patients undergoing surgical treatment for varicocele from September 2011 to March 2020 in the same clinical centre. Enrolled males performed at least one semen analysis before and one after surgical varicocele correction. Primary outcome was the detailed morphologic microscopic sperm evaluation. Secondary outcomes were conventional semen analyses.

Results

A total of 121 males (mean age 24.6 ± 6.1 years) were enrolled. Using detailed morphologic microscopic sperm evaluation, a significant morphological improvement was recorded, with a reduction in head and tail abnormalities. Moreover, a significant increase in sperm concentration (p = 0.015) and percentage of progressive and total motility (p = 0.022 and p = 0.039) were observed after surgery. The multivariate logistic analysis identified the ultrasonography varicocele degree before surgery as a main predictor of the sperm concentration improvement (p = 0.016), with the highest improvement for varicocele of I and II degree.

Discussion

For the first time, the detailed morphologic microscopic sperm evaluation highlights a relevant reduction in sperm abnormalities after varicocele surgery, showing its potential application in clinical practice.

Membrane Estrogen Receptor (GPER) and Follicle-Stimulating Hormone Receptor (FSHR) Heteromeric Complexes Promote Human Ovarian Follicle Survival

Classically, follicle-stimulating hormone receptor (FSHR)-driven cAMP-mediated signaling boosts human ovarian follicle growth and oocyte maturation. However, contradicting in vitro data suggest a different view on physiological significance of FSHR-mediated cAMP signaling. We found that the G-protein-coupled estrogen receptor (GPER) heteromerizes with FSHR, reprogramming cAMP/death signals into proliferative stimuli fundamental for sustaining oocyte survival. In human granulosa cells, survival signals are missing at high FSHR:GPER ratio, which negatively impacts follicle maturation and strongly correlates with preferential Gαs protein/cAMP-pathway coupling and FSH responsiveness of patients undergoing controlled ovarian stimulation. In contrast, FSHR/GPER heteromers triggered anti-apoptotic/proliferative FSH signaling delivered via the Gβγ dimer, whereas impairment of heteromer formation or GPER knockdown enhanced the FSH-dependent cell death and steroidogenesis. Therefore, our findings indicate how oocyte maturation depends on the capability of GPER to shape FSHR selective signals, indicating hormone receptor heteromers may be a marker of cell proliferation.

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G-protein-coupled estrogen receptor (GPER) interacts with FSH receptor (FSHR)

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FSHR/GPER heteromers reprogram FSH-induced death signals to proliferative stimuli

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Anti-apoptotic signaling of heteromers is via a GPER-Gαs inhibitory complex and Gβγ

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Heteromer formation impacts follicle maturation and FSH responses of IVF patients

Two human menopausal gonadotrophin (hMG) preparations display different early signaling in vitro

Commercial hMG drugs are marketed for the treatment of infertility and consist of highly purified hormones acting on receptors expressed in target gonadal cells. Menopur® and Meriofert® are combined preparation of FSH and hCG and are compared in vitro herein. To this purpose, the molecular composition of the two drugs was analyzed by immunoassay. The formation of FSH receptor and LH/hCG receptor (FSHR; LHCGR) heteromer, intracellular Ca2+ and cAMP activation, β-arrestin 2 recruitment and the synthesis of progesterone and estradiol were evaluated in transfected HEK293 and human primary granulosa lutein cells treated by drugs administered within the pg-mg/ml concentration range. Molecular characterization revealed that Meriofert® has a higher FSH:hCG ratio than Menopur® which, in turn, displays the presence of LH molecules. While both drugs induced similar FSHR-LHCGR heteromeric formations and intracellular Ca2+ increase, Meriofert® had a higher potency than Menopur® in inducing a cAMP increase. Moreover, Meriofert® revealed a higher potency than Menopur® in recruiting β-arrestin 2, likely due to different FSH content modulating the tridimensional structure of FSHR-LHCGR-β-arrestin 2 complexes, as evidenced by a decrease in bioluminescence resonance energy transfer signal. This drug-specific activation of intracellular signaling pathways is consistent with the molecular composition of these preparations and impacts downstream progesterone and estradiol production, with Menopur® more potent than Meriofert® in inducing the synthesis of both the steroids. These findings are suggestive of distinct in-vivo activities of these preparations, but require cautious interpretation and further validation from clinical studies.

OR24-04 Ovarian Follicle Survival Is Determined by Follicle-Stimulating Hormone Receptor (FSHR) and Estrogen Receptor (GPER) Heteromers

Mechanisms regulating the selection of antral ovarian follicles are poorly understood and supposed to rely on low estrogen levels, decline of follicle-stimulating hormone (FSH) levels and receptor (FSHR) expression. These concepts are challenged in vitro, where apoptosis of human granulosa cells (hGLC) and transfected cell lines is induced by high doses of FSH or FSHR overexpression, while estrogens induce anti-apoptotic signals via nuclears and a G protein-coupled estrogen receptor (GPER). Therefore, in vitro data suggest that antral follicle selection may be driven by underestimated, FSH/FSHR-dependent apoptotic signals due to transiently maximized FSHR expression and overload of cAMP signalling, prevailing on estrogen-dependent signals. Here we demonstrate how FSHR/GPER physical interaction rescue ovarian follicles from FSH-mediated death. 10 nM FSH induces high intracellular levels of cAMP, measured by bioluminescence resonance energy transfer (BRET), and apoptosis in cultured hGLC under conditions where GPER levels are depleted by siRNA. This result was confirmed in transfected HEK293 cells overexpressing FSHR. Using BRET, photo-activated localization microscopy (PALM) and bioinformatics prodiction, we also demonstrate FSHR/GPER heteromers at the cell surface. The role of FSHR/GPER heteromers may be relevant to inhibit FSH-induced death signals, since increasing GPER expression levels in HEK293 cells co-expressing FSHR results in displacement of the Gαs-protein to FSHR, blockade of FSH-induced cAMP production and inhibition of apoptosis. However, in HEK293 cells coexpressing GPER/FSHR, FSH-induced activation of the anti-apoptotic AKT-pathway via a Gβγ-dependent mechanism, as demonstrated by Western blotting in cells treated using the inhibitor gallein. Inhibition of both FSH-induced cAMP production and apoptosis was lost when FSHR is coexpressed together with a mutant GPER, unable to heteromerize with FSHR, as well as in KO HEK293 cells unable to produce a molecular complex associated with GPER inhibiting cAMP. GPER/FSHR coexpression is confirmed in secondary follicles from paraffin-embedded tissues of human ovary by immunohistochemistry, suggesting that FSHR-GPER heterodimers could be physiologically relevant in vivo for inhibiting cAMP-linked apoptosis. Most importantly, FSHR and GPER co-expression correlates in hGLC from FSH-normo-responder women undergoing assisted reproduction, while it is not in hGLC from FSH-poor-responders, where increasing FSHR mRNA levels do not correspond to increasing GPER mRNA levels. We demonstrate that death signals in atretic follicles are delivered through overexpressed FSHR and inhibited by FSHR/GPER heteromerization, activating anti-apoptotic pathways. This finding unveils a novel working model of the physiology of dominant follicle selection and the relationship between FSH and estrogens.

β-arrestin 2 Is a Prognostic Factor for Survival of Ovarian Cancer Patients Upregulating Cell Proliferation

Establishing reliable prognostic factors as well as specific targets for new therapeutic approaches is an urgent requirement in advanced ovarian cancer. For several tumor entities, the ubiquitously spread scaffold protein β-arrestin 2, a multifunctional scaffold protein regulating signal transduction and internalization of activated G protein-coupled receptors (GPCRs), has been considered with rising interest for carcinogenesis. Therefore, we aimed to elucidate the prognostic impact of β-arrestin 2 and its functional role in ovarian cancer. β-arrestin 2 expression was analyzed in a subset of 156 samples of ovarian cancer patients by immunohistochemistry. Cytoplasmic expression levels were correlated with clinical as well as pathological characteristics and with prognosis. The biologic impact of β-arrestin 2 on cell proliferation and survival was evaluated, in vitro. Following transient transfection by increasing concentrations of plasmid encoding β-arrestin 2, different cell lines were evaluated in cell viability and death. β-arrestin 2 was detected in all histological ovarian cancer subtypes with highest intensity in clear cell histology. High β-arrestin 2 expression levels correlated with high-grade serous histology and the expression of the gonadotropin receptors FSHR and LHCGR, as well as the membrane estrogen receptor GPER and hCGβ. Higher cytoplasmic β-arrestin 2 expression was associated with a significantly impaired prognosis (median 29.88 vs. 50.64 months; P = 0.025). Clinical data were confirmed in transfected HEK293 cells, human immortalized granulosa cell line (hGL5) and the ovarian cancer cell line A2780 in vitro, where the induction of β-arrestin 2 cDNA expression enhanced cell viability, while the depletion of the molecule by siRNA resulted in cell death. Reflecting the role of β-arrestin 2 in modulating GPCR-induced proliferative and anti-apoptotic signals, we propose β-arrestin 2 as an important prognostic factor and also as a promising target for new therapeutic approaches in advanced ovarian cancer.