Dysregulation of FGFR signalling by a selective inhibitor reduces germ cell survival in human fetal gonads of both sexes and alters the somatic niche in fetal testes

STUDY QUESTION

Does experimental manipulation of fibroblast growth factor 9 (FGF9)-signalling in human fetal gonads alter sex-specific gonadal differentiation?

SUMMARY ANSWER

Inhibition of FGFR signalling following SU5402 treatment impaired germ cell survival in both sexes and severely altered the developing somatic niche in testes, while stimulation of FGF9 signalling promoted Sertoli cell proliferation in testes and inhibited meiotic entry of germ cells in ovaries.

WHAT IS KNOWN ALREADY

Sex-specific differentiation of bipotential gonads involves a complex signalling cascade that includes a combination of factors promoting either testicular or ovarian differentiation and inhibition of the opposing pathway. In mice, FGF9/FGFR2 signalling has been shown to promote testicular differentiation and antagonize the female developmental pathway through inhibition of WNT4.

STUDY DESIGN, SIZE, DURATION

FGF signalling was manipulated in human fetal gonads in an established ex vivo culture model by treatments with recombinant FGF9 (25 ng/ml) and the tyrosine kinase inhibitor SU5402 (10 μM) that was used to inhibit FGFR signalling. Human fetal testis and ovary tissues were cultured for 14 days and effects on gonadal development and expression of cell lineage markers were determined.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Gonadal tissues from 44 male and 33 female embryos/fetuses from first trimester were used for ex vivo culture experiments. Tissues were analyzed by evaluation of histology and immunohistochemical analysis of markers for germ cells, somatic cells, proliferation and apoptosis. Culture media were collected throughout the experimental period and production of steroid hormone metabolites was analyzed in media from fetal testis cultures by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

MAIN RESULTS AND THE ROLE OF CHANCE

Treatment with SU5402 resulted in near complete loss of gonocytes (224 vs. 14 OCT4+ cells per mm2, P < 0.05) and oogonia (1456 vs. 28 OCT4+ cells per mm2, P < 0.001) in human fetal testes and ovaries, respectively. This was a result of both increased apoptosis and reduced proliferation in the germ cells. Addition of exogenous FGF9 to the culture media resulted in a reduced number of germ cells entering meiosis in fetal ovaries (102 vs. 60 γH2AX+ germ cells per mm2, P < 0.05), while in fetal testes FGF9 stimulation resulted in an increased number of Sertoli cells (2503 vs. 3872 SOX9+ cells per mm2, P < 0.05). In fetal testes, inhibition of FGFR signalling by SU5402 treatment altered seminiferous cord morphology and reduced the AMH expression as well as the number of SOX9-positive Sertoli cells (2503 vs. 1561 SOX9+ cells per mm2, P < 0.05). In interstitial cells, reduced expression of COUP-TFII and increased expression of CYP11A1 and CYP17A1 in fetal Leydig cells was observed, although there were no subsequent changes in steroidogenesis.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Ex vivo culture may not replicate all aspects of fetal gonadal development and function in vivo. Although the effects of FGF9 were studied in ex vivo culture experiments, there is no direct evidence that FGF9 acts in vivo during human fetal gonadogenesis. The FGFR inhibitor (SU5402) used in this study is not specific to FGFR2 but inhibits all FGF receptors and off-target effects on unrelated tyrosine kinases should be considered.

WIDER IMPLICATIONS OF THE FINDINGS

The findings of this study suggest that dysregulation of FGFR-mediated signalling may affect both testicular and ovarian development, in particular impacting the fetal germ cell populations in both sexes.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by an ESPE Research Fellowship, sponsored by Novo Nordisk A/S to A.JØ. Additional funding was obtained from the Erichsen Family Fund (A.JØ.), the Aase and Ejnar Danielsens Fund (A.JØ.), the Danish Government's support for the EDMaRC programme (A.JU.) and a Wellcome Trust Intermediate Clinical Fellowship (R.T.M., Grant no. 098522). The Medical Research Council (MRC) Centre for Reproductive Health (R.T.M.) is supported by an MRC Centre Grant (MR/N022556/1). The authors have no conflict of interest to disclose.

Ex vivo culture of human fetal gonads: manipulation of meiosis signalling by retinoic acid treatment disrupts testis development

STUDY QUESTION

What are the effects of experimentally manipulating meiosis signalling by addition of retinoic acid (RA) in cultured human fetal gonads?

SUMMARY ANSWER

RA-treatment accelerated meiotic entry in cultured fetal ovary samples, while addition of RA resulted in a dysgenetic gonadal phenotype in fetal testis cultures.

WHAT IS KNOWN ALREADY

One of the first manifestations of sex differentiation is the initiation of meiosis in fetal ovaries. In contrast, meiotic entry is actively prevented in the fetal testis at this developmental time-point. It has previously been shown that RA-treatment mediates initiation of meiosis in human fetal ovary ex vivo.

STUDY DESIGN, SIZE, DURATION

This was a controlled ex vivo study of human fetal gonads treated with RA in 'hanging-drop' tissue cultures. The applied experimental set-up preserves germ cell-somatic niche interactions and the investigated outcomes included tissue integrity and morphology, cell proliferation and survival and the expression of markers of meiosis and sex differentiation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Tissue from 24 first trimester human fetuses was included in this study, all from elective terminations at gestational week (GW) 7-12. Gonads were cultured for 2 weeks with and without addition of 1 µM RA. Samples were subsequently formalin-fixed and investigated by immunohistochemistry and cell counting. Proteins investigated and quantified included; octamer-binding transcription factor 4 (OCT4), transcription factor AP-2 gamma (AP2γ) (embryonic germ cell markers), SRY (sex determining region Y)-box 9 (SOX9), anti-Müllerian hormone (AMH) (immature Sertoli cell markers), COUP transcription factor 2 (COUP-TFII) (marker of interstitial cells), forkhead box L2 (FOXL2) (granulosa cell marker), H2A histone family, member X (γH2AX) (meiosis marker), doublesex and mab-3 related transcription factor 1 (DMRT1) (meiosis regulator), cleaved poly ADP ribose polymerase (PARP), cleaved Caspase 3 (apoptosis markers) and Ki-67 antigen (Ki-67) (proliferation marker). Also, proliferation was determined using a 5'-bromo-2'-deoxyuridine (BrdU) incorporation assay.

MAIN RESULTS AND THE ROLE OF CHANCE

A novel ex vivo 'hanging-drop' culture model for human fetal gonads was successfully established. Continued proliferation of cells without signs of increased apoptosis was observed after 2 weeks of culture. In cultured fetal ovaries treated with RA, an increased number of meiotic germ cells (P < 0.05) and DMRT1-positive oogonia initiating meiosis (P < 0.05) was observed, which is in agreement with a previous study. In fetal testes, RA-treatment resulted in a decreased number of gonocytes (P < 0.05), a reduced percentage of proliferating gonocytes (P < 0.05), altered expression pattern of the somatic cell markers AMH and COUP-TFII, as well as disrupted seminiferous cord structure and testis morphology.

LIMITATIONS, REASONS FOR CAUTION

The number of samples included in this study was relatively small due to the limited availability of human fetal tissue.

WIDER IMPLICATIONS OF THE FINDINGS

The hanging-drop culture, similarly to other organ culture approaches, allows studies of germ cell-somatic niche interactions and determination of effects after manipulating specific signalling pathways. Our novel finding of disrupted fetal testis development after treatment with RA indicates that abnormal meiosis regulation can potentially cause gonadal dysgenesis. Further studies will elucidate the exact mechanisms and timing of observed effects.

STUDY FUNDING/COMPETING INTERESTS

This work was supported in part by an ESPE Research Fellowship, sponsored by Novo Nordisk A/S to A.Jø. Additional funding for this project was obtained from The Research Council of the Capital Region of Denmark (E.R.-D.M.), The Research Fund at Rigshospitalet (A.Ju. and J.E.N.), Familien Erichssens Fund (A.Jø.), Dagmar Marshalls Fund (A.Jø.) and Aase & Ejnar Danielsens Fund (A.Jø.). The authors have no conflicts of interest.

Obesity and survival among women with ovarian cancer: results from the Ovarian Cancer Association Consortium

Background:

Observational studies have reported a modest association between obesity and risk of ovarian cancer; however, whether it is also associated with survival and whether this association varies for the different histologic subtypes are not clear. We undertook an international collaborative analysis to assess the association between body mass index (BMI), assessed shortly before diagnosis, progression-free survival (PFS), ovarian cancer-specific survival and overall survival (OS) among women with invasive ovarian cancer.

Methods:

We used original data from 21 studies, which included 12 390 women with ovarian carcinoma. We combined study-specific adjusted hazard ratios (HRs) using random-effects models to estimate pooled HRs (pHR). We further explored associations by histologic subtype.

Results:

Overall, 6715 (54%) deaths occurred during follow-up. A significant OS disadvantage was observed for women who were obese (BMI: 30–34.9, pHR: 1.10 (95% confidence intervals (CIs): 0.99–1.23); BMI: ⩾35, pHR: 1.12 (95% CI: 1.01–1.25)). Results were similar for PFS and ovarian cancer-specific survival. In analyses stratified by histologic subtype, associations were strongest for women with low-grade serous (pHR: 1.12 per 5 kg m⁻²) and endometrioid subtypes (pHR: 1.08 per 5 kg m⁻²), and more modest for the high-grade serous (pHR: 1.04 per 5 kg m⁻²) subtype, but only the association with high-grade serous cancers was significant.

Conclusions:

Higher BMI is associated with adverse survival among the majority of women with ovarian cancer.

Prediction of suboptimal primary cytoreduction in primary ovarian cancer with combined positron emission tomography/computed tomography--a prospective study

OBJECTIVE

To prospectively identify combined PET/CT predictors of incomplete/suboptimal primary cytoreduction in advanced ovarian cancer.

METHODS

From September 2004 to March 2007, 179 patients with a Risk of Malignancy Index (RMI) >150 based on serum CA-125, ultrasound examinations and menopausal state, underwent PET/CT within 2 weeks prior to standard surgery/debulking of a pelvic tumor. Ten PET/CT features were identified and evaluated as predictors of cytoreduction in 54 patients with advanced ovarian cancer.

RESULTS

Complete cytoreduction (no macroscopic residual disease) was achieved in 35% and optimal cytoreduction (<1 cm residual disease) was achieved in 56%. Using univariate analysis, predictors of incomplete cytoreduction were large bowel mesentery implants (LBMI) (P<0.003), pleural effusion (P<0.009), ascites (P<0.009) and peritoneal carcinosis (P<0.01). LBMI (P<0.03) and ascites (P<0.05) were also predictors of suboptimal cytoreduction. Using multivariate analysis, LBMI was the only independent predictor of incomplete cytoreduction (P=0.004) and no predictor of suboptimal cytoreduction was found.

CONCLUSION

PET/CT predictors of cytoreduction were found. But they should not be used to withhold patients form primary cytoreductive surgery. We suggest PET/CT as a supplementary image modality prior to surgery in primary OC patients whenever accurate and comprehensive preoperative evaluation of primary tumor and metastases is desired.

Surgical cytoreduction in recurrent ovarian carcinoma in patients with complete response to paclitaxel-platinum

AIM

The objective was to analyse the impact of secondary cytoreductive surgery in patients with recurrent ovarian carcinoma.

METHODS

Retrospective review of 572 consecutive patients with primary ovarian carcinoma. Thirty-eight patients with intraabdominal/pelvic recurrence consisted the study group. Clinical variables affecting tumour resectability and survival were evaluated.

RESULTS

Complete tumour resection was obtained in 42% of patients. A solitary tumour recurrence was independently associated with complete tumour resection (p=0.009). Median survival for patients with complete and incomplete tumour resection was 51.8 and 19.9 months. The parameter, residual tumour, was found independently correlated with survival after the relapse surgical procedure (p=0.02). However, including also the parameter, number of relapse tumour sites, in the multivariate analysis, the parameter, residual tumour, was no longer significantly associated with survival.

CONCLUSIONS

Complete tumour resection following secondary cytoreductive surgery is associated with improved survival in selected groups of patients with recurrent ovarian cancer. However, other clinical factors than surgical cytoreduction are of considerable significance in determining the outcome of the salvage treatment.

[Selective foeticidium using YAG laser]

Twin-to-twin transfusion syndrome was found by ultrasound in monochorionic diamniotic twins in week 20. The donor had hydrocephalus and the recipient was normal. Selective foeticide was performed by coagulating the vessels of the umbilical cord of the donor with a YAG-laser. The pregnancy continued without complications and a healthy girl was born in week 34. The birth weight was 2935 g. Psychomotor development was normal at the age of six months.

[Consensus on the treatment and control of border-line tumors of the ovary in Denmark]

In order to obtain an impression of the consensus in Denmark of the treatment and control of border-line tumours of the ovary (BTO), a questionnaire was sent to all 43 departments of gynaecology/obstetrics and of surgery with gynaecology/obstetrics. Thirty-seven (86%) departments replied. The results of the investigation are presented. It is concluded that about 75% (87% in stage Ia and 65% in stage Ib) perform restrictive surgery on younger patients in the early stages. Indication for chemotherapy is found only in patients with more advanced stages. Very few find an indication for radiotherapy. Treatment and control of BTO in Denmark are in agreement with current international principles.

Perioperative blood transfusion and recurrence and death after resection for cancer of the colon and rectum

Several reports have claimed that perioperative blood transfusion promotes recurrence and death after cancer surgery. We studied the effect of transfusion in 315 patients who had radical resection for carcinoma of the colon and rectum. The disease recurred in 113 (42%) of 268 transfused patients, versus in 15 (32%) in 47 non-transfused patients (P = 0.2). Of the transfused patients 102 (38%) died of colon cancer, versus 13 patients (28%) in the non-transfused group (P = 0.2). The 5-year recurrence-free survival rate was 0.59 in the transfused patients and 0.72 in the non-transfused group (P = 0.10). When differences in confounding background variables were accounted for by Cox multiple regression analysis, the significance of transfusion was even less. The study does not support the hypothesis that perioperative blood transfusion promotes recurrence after operation for colorectal cancer.

Diagnostic value of an abnormal smear in non-pregnant women. Evaluation of positive smear from the surface of the portio obtained by the cottonswab method or by the dry wooden Ayre spatula and the relevance of positive smear from the endocervix and/or from the surface of the portio

During a 3-4 year period, 324 women with a positive smear were registered consecutively and prospectively and divided into two groups according to the design of the investigation. In one group the smear was taken with an Ayre spatula and in the other group with a cotton swab. The purpose of this investigation has been to make a comparison between the endocervical smear and the smear taken from the surface of the portio and at the same time between the samples taken with a dry wooden Ayre spatula and with a cotton swab. No differences were found. The cytological findings have been registered and correlated both with the histological findings by colposcopically directed punch-biopsies and endocervical curettings and with the final histological diagnosis obtained by punch-biopsy, conization or hysterectomy.

[Intermittent claudication--social aspects in young patients not undergoing surgical treatment]

A total of 107 patients suffering from intermittent claudication (CI) was studied after a mean observation time of 5.9 years. Thirty-one (29%) had died during the observation period. A questionnaire was sent to 76 patients and 78% replied. All patients were under 50 years of age at the first consultation. No patients had been operated upon. The ratio women:men was 1:1.3. 33% received disability pensions or some other kind of pensions. Fifty-eight had limited their spare-time activities because of CI. It is concluded that a close control and reconstructive arteria surgery must still be recommended when the working ability is threatened.

Comparison between abnormal cytology, colposcopy and histopathology during pregnancy

During a 3 year period, 35 pregnant woman with grade III or IV cytological changes found at pregnancy control were followed during pregnancy and up to 4 years after delivery. These 35 patients constitute 0.35% of all the pregnant women admitted for antepartum consultation. Complete regression of dysplasia was seen in one third of the patients. The patients were followed with colposcopy and sometimes punch biopsy and the decision regarding final treatment was postponed until 8 weeks after delivery. No invasive lesion was found, and no recurrences or invasive lesions were found at follow up. It is concluded that cytology and colposcopy with punch biopsy on suspicion of early invasion is an adequate control procedure during the pregnancy at intervals of 2-3 months.

Peritonitis caused by abscess in the seminal vesicle. Case report

Acute seminal vesiculitis is rare. It is most often associated with prostatitis and epididymitis. A case is presented in which a ruptured abscess of the seminal vesicle caused diffuse peritonitis. There appears to be no previous report of such abscess, which thus seems to be a very rare cause of acute abdomen.