Gonadotrophins inhibit and activin induces expression of inhibin/activin beta(B) subunit mRNA in cultured human granulosa-luteal cells

Effectiveness of different treatment modalities for the management of adult-onset granulosa cell tumours of the ovary (primary and recurrent)

BACKGROUND

Granulosa cell tumour is a rare gynaecological tumour of the ovary with recurrences many years after initial diagnosis and treatment. Evidence-based management of granulosa cell tumour of the ovary is limited, and treatment has not been standardised. Surgery, including fertility-sparing procedures for young women, has traditionally been the standard treatment. Adjuvant treatments following surgery have been based on non-randomised trials. A combination of bleomycin, etoposide and cisplatin (BEP) has traditionally been used for treatment of advanced and/or recurrent disease that cannot be optimally managed surgically.

OBJECTIVES

To evaluate the effectiveness and safety of different treatment modalities offered in current practice for the management of primary, residual and recurrent adult-onset granulosa cell tumours (GCTs) of the ovary.

SEARCH METHODS

We searched the Cochrane Gynaecological Cancer Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE up to December 2013. We also searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs), quasi-RCTs and observational studies that examined women with adult-onset granulosa cell tumours of the ovary (primary and recurrent). For non-randomised studies, we included studies that used multivariate analysis to adjust for baseline characteristics.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data and assessed risk of bias. Studies were heterogeneous with respect to treatment comparisons, so data were not synthesised in meta-analyses, and methods for assessing heterogeneity were not needed. Risk of bias in included studies was assessed by using the six core items used to assess RCTs and by evaluating four additional criteria specifically addressing risk of bias in non-randomised studies.

MAIN RESULTS

Five retrospective cohort studies (535 women with a diagnosis of GCT) that used appropriate statistical methods for adjustment were included in the review.Two studies, which carried out multivariate analyses that attempted to identify factors associated with better outcomes (in terms of overall survival), reported no apparent evidence of a difference in overall survival between surgical approaches, whether a participant underwent lymphadenectomy or received adjuvant chemotherapy or radiotherapy. Only percentage of survival for all participants combined was reported in two trials and was not reported at all in one study.One study showed that women who received postoperative radiotherapy had lower risk of disease recurrence compared with those who underwent surgery alone (adjusted hazard ratio (HR) 0.3, 95% confidence interval (CI) 0.1 to 0.6, P value 0.04). Three studies reportedthat there was no evidence of differences in disease recurrence based on execution and type of adjuvant chemotherapy or on type of surgery or surgical approach, other than that surgical staging may be important. One study described no apparent evidence of a difference in disease recurrence between fertility-sparing surgery and conventional surgery. Recurrence-free survival was not reported in one study.Toxicity and adverse event data were incompletely reported in the five studies. None of the five studies reported on quality of life (QoL). All studies were at very high risk of bias.

AUTHORS' CONCLUSIONS

One study showed a lower recurrence rate with the use of adjuvant radiotherapy, although this study was at high risk of bias and the results should be interpreted with caution. After evaluating the five small retrospective studies, we are unable to reach any firm conclusions as to the effectiveness and safety of different types and approaches of surgery, including conservative surgery, as well as adjuvant chemotherapy or radiotherapy, for management of GCTs of the ovary. The available evidence is very limited, and the review provides only low-quality evidence. Further research is very likely to have an important impact on our confidence in the estimate of effect and may alter our findings.Ideally, multinational RCTs are needed to answer these questions. The disease is relatively rare and generally has a good prognosis. RCTs are challenging to conduct, but three ongoing trials have been identified, demonstrating that they are feasible, although two of these studies are single-arm trials. The study that may be able to provide answers to the question of which chemotherapeutic regimen should be selected for management of sex cord stromal tumours is an ongoing, randomised, phase 2 study, led by the Gynaecological Oncology Group to compare the efficacy of carboplatin and paclitaxel versus standard BEP. These investigators are also looking into the value of inhibin A and inhibin B as predictive biomarkers. Additional trials are required to assess toxicity and QoL associated with different treatment regimens as well as the safety of conservative surgical options.

GnRH agonist therapy in a patient with recurrent ovarian granulosa cell tumors

A 65-yr-old woman presented 17 yr status post-hysterectomy with bilateral ovarian salpingo-oophorectomy, attributable to ovarian cancer. She was admitted to our hospital, with multiple cystic liver masses and multiple large seeded masses in her abdomen and pelvic cavity. Histological examination of the pelvic masses demonstrated granulosa cell tumors. After two courses of systemic combination chemotherapy, with paclitaxel and carboplatin, the masses in the abdomen and pelvic cavity increased, and debulking surgery also failed because of peritoneal dissemination with severe adhesion. Finally, she underwent palliative radiotherapy for only the pelvic masses obstructing the urinary and GI tracts, and monthly hormonal therapy with a gonadotrophin-releasing hormone agonist; leuprorelin 3.75 mg IM. Subsequently, multiple masses beyond the range of the radiation as well as those within the radiotherapy field partially decreased. This partial response had been maintained for more than 8 months as of the last follow-up visit. Owing to its long and indolent course and the low metabolic rate of the tumors, advanced or recurrent granulosa cell tumor (GCT) requires treatment options beyond chemotherapy, surgery, and radiotherapy. Hormonal agents may provide another treatment option for advanced or recurrent GCT in those who are not candidates for surgery, chemotherapy, or radiotherapy.

Human granulosa-lutein cell in vitro production of progesterone, inhibin A, inhibin B, and activin A are dependent on follicular size and not the presence of the oocyte

OBJECTIVE

To investigate inhibin A, inhibin B, activin A, and P production by cultured granulosa cells (GCs) and what relationship this hormone production has to fertility.

DESIGN

Luteinized GCs from individual follicles were cultured, and inhibin A, inhibin B, activin A, and P production were measured by ELISA at 24 and 72 hours.

SETTING

Research laboratory and university hospital.

PATIENT(S)

Fifteen women who undertook an IVF-ICSI program, yielding 58 follicles.

INTERVENTION(S)

Individual follicular aspiration and preparation of GCs for culture.

MAIN OUTCOME MEASURE(S)

Inhibin A, inhibin B, activin A, and P production; oocyte retrieval; and fertility outcome.

RESULT(S)

Inhibin A, inhibin B, and P continued to be secreted by GCs in vitro, and activin A levels were detected only marginally in 56% of cultures. The rate of production also was dependent on the size of follicle from which the GCs originated but not on oocyte presence or ability to fertilize. Granulosa cell stimulation with hCG had no effect on inhibin A but increased P and decreased inhibin B production.

CONCLUSION(S)

A marked effect of luteal differentiation appears to be the inhibition of inhibin B production in response to hCG stimulation. Luteinized GC function, with respect to inhibins, activin A, and P production, was not influenced by the presence or absence of an oocyte and did not correlate with fertility outcome. However, follicle size did influence rates of local hormone production.

Anastrozole therapy in recurrent ovarian adult granulosa cell tumors: A report of 2 cases

BACKGROUND

Ovarian sex cord stromal tumors are frequently hormonally active, and adult granulosa cell tumors often demonstrate estrogen receptor positivity. Thus, hormonal agents have been evaluated as potential treatments for advanced stage or recurrent adult granulosa cell tumors.

CASE

Two cases of patients with recurrent adult granulosa cell tumors are presented. Each patient received multiple treatment modalities including chemotherapy and had previously progressed on leuprolide. Both patients were started on anastrozole with subsequent normalization of inhibin B levels and clinical exams. They have been maintained on treatment for 14 and 18 months, respectively, and have tolerated the drug without difficulty.

CONCLUSION

Aromatase inhibitors may be a viable treatment option for women with advanced stage or recurrent ovarian adult granulosa cell tumors.

Expression of inhibin-activin subunits, follistatin and smads in granulosa-luteal cells collected at oocyte retrieval

PURPOSE

To examine the expression of inhibin-activin subunits, follistatin, and Smads 2, 3 and 4 in granulosa-luteal cells at the time of oocyte retrieval.

METHODS

Quantitative reverse transcriptase-polymerase chain reaction was performed to quantify the mRNA expression of the investigated genes: inhibin alpha-subunit, inhibin-activin betaA- and betaB-subunits, follistatin, and Smads 2, 3 and 4.

RESULTS

alpha-, betaA- and betaB-subunits of inhibin-activin, and follistatin were all well expressed in granulosa-luteal cells obtained from either dominant or cohort follicles. alpha-subunits strongly correlated with Smad2 (p < 0.001). betaA-subunit significantly correlated with Smad4, p < 0.001. betaB-subunit significantly correlated with Smad2, p = 0.002, and follistatin expression strongly correlated with the expression of Smads 2 and 4 (p < 0.001 and = 0.007 respectively).

CONCLUSIONS

We found, for the first time that inhibin-activin betaB-subunit mRNA was well expressed in human granulosa-luteal cells obtained from either dominant or cohort follicles. alpha-, betaA- and betaB-subunits and follistatin correlated with Smads to varied degrees, suggesting the active roles of the above genes at the time of oocyte retrieval.

Involvement of cyclic adenosine 3',5'-monophosphate in the differential regulation of activin betaA and betaB expression by gonadotropin in the zebrafish ovarian follicle cells

Activin is a dimeric protein consisting of two similar but distinct beta-subunits, betaA and betaB. In our previous studies, both activin A (betaAbetaA) and activin B (betaBbetaB) have been demonstrated to stimulate oocyte maturation and promote oocyte maturational competence in the zebrafish. Follistatin, a specific activin-binding protein, can block both activin- and gonadotropin-induced final oocyte maturation in vitro, suggesting that activin is likely a downstream mediator of gonadotropin actions in the zebrafish ovary. In the present study, a full-length cDNA encoding zebrafish ovarian activin betaA was cloned and sequenced. The precursor of zebrafish activin betaA consists of 395 amino acids and its mature region exhibits about 78% homology with that of mammals. Using an in vitro primary culture of the ovarian follicle cells and semiquantitative RT-PCR assays, we examined the regulation of activin betaA and betaB expression by human chorionic gonadotropin (hCG) and its intracellular signal transduction mechanisms. hCG (15 IU/ml) increased the mRNA level of activin betaA-subunit; however, it significantly down-regulated the steady-state expression level of activin betaB in a time- and dose-dependent manner. The differential regulation of the two beta-subunits by hCG could be mimicked by 3-isobutyl-1-methylxanthine, forskolin, and dibutyryl-cAMP, suggesting involvement of the intracellular cAMP pathway. Interestingly, H89 (a specific inhibitor of protein kinase A, PKA) could effectively block hCG- and forskolin-stimulated activin betaA expression at 10 micro M, but it was unable to reverse the inhibitory effects of hCG and forskolin on betaB expression. This suggests that the hCG-stimulated activin betaA expression is dependent on the activation of the cAMP-PKA pathway, whereas the inhibitory effect of hCG on activin betaB expression is likely mediated by PKA-independent pathway(s).

Engagement of activin and bone morphogenetic protein signaling pathway Smad proteins in the induction of inhibin B production in ovarian granulosa cells

In the mammalian ovary cell growth and differentiation is regulated by several members of the transforming growth factor beta (TGF beta) superfamily including activins, inhibins, growth differentiation factors and bone morphogenetic proteins (BMPs). The effects of TGF beta family members are mediated to the target cells via heteromeric complexes of type I and II serine/threonine kinase receptors which activate Smad signaling protein pathways in various cell types. We have previously shown that inhibin B, a hormonally important product from human granulosa cells, is up regulated by activin and BMPs. Here, we report the use of adenoviral gene transfer methodology to manipulate the TGF beta growth factor signaling system in primary cultures of human granulosa cells. These cells are exceedingly difficult to transfect by conventional transfection methods, but were virtually 100% infected with recombinant adenoviruses expressing green fluorescent protein (GFP). Adenoviruses expressing constitutively active forms of the seven known mammalian type I activin receptor-like kinase receptors (Ad-caALK1 through Ad-caALK7) cause activation of endogenous and adenovirally transferred Smad signaling proteins so that Ad-caALK1/2/3/6 and Ad-caALK4/5/7 induced phosphorylation of the Smad1 and Smad2 pathways, respectively. Activin A and BMP-2 activated the Smad1 and Smad2 pathways as well as inhibin B production as did all the Ad-caALKs. Furthermore, overexpression of adenoviral Smad1 and Smad2 proteins without exogenously added ligands induced inhibin B production. The inhibitory Smad7 protein suppressed BMP-2 and activin induced inhibin B production. Collectively, the present data demonstrate that adenoviral gene transfer provides an effective approach for dissecting the TGF beta signaling pathways in primary ovarian cells in vitro and more specifically indicate that the Smad1 and Smad2 pathways are involved in the regulation of inhibin B production by TGF beta family ligands in the ovary.

Gonadotropin regulation of activin betaA and activin type IIA receptor expression in the ovarian follicle cells of the zebrafish, Danio rerio

We have previously demonstrated that both activin and its receptors are expressed in the zebrafish ovary, suggesting paracrine roles for activin in the ovarian functions. Activin significantly stimulated zebrafish oocyte maturation in vitro, and this effect could be blocked by follistatin, an activin-binding protein. Interestingly, follistatin also blocked the stimulatory effect of gonadotropin (hCG) on the oocyte maturation. Taken together, these results have led to a hypothesis that the ovarian activin system may play a role in mediating the actions of gonadotropin in the ovary. To test this hypothesis, the present study was undertaken to investigate if gonadotropin has any effect on the expression of activin betaA subunit and activin type IIA (ActRIIA) receptor in the zebrafish ovary. A primary culture of zebrafish ovarian follicle cells was established in the present study, and the cultured cells expressed both activin betaA and ActRIIA receptor when assayed with RT-PCR. The primary culture consisted of three major types of cells, presumably the fibroblasts, the thecal cells and the granulosa cells, according to the morphological features, histochemical staining for 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and RT-PCR for aromatase. Using a semi-quantitative RT-PCR with beta-actin as the internal control, we demonstrated that hCG significantly stimulated mRNA expression of both activin betaA and ActRIIA receptor in the cultured follicle cells in a time- and dose-dependent manner. Treatment of the cells with hCG quickly increased the steady-state mRNA levels of activin betaA and ActRIIA receptor, and the effect peaked at 2 h of treatment. The stimulatory effect of gonadotropin diminished with longer treatment and no effect was observed at 8 h of treatment. The effect of hCG also exhibited strong dose dependence when assayed at 2 h of treatment. The levels of activin betaA and ActRIIA receptor mRNA elevated with increasing dose of hCG; however, the effect significantly decreased at dosage higher than 15 IU/ml. Consistent with the stimulatory effect of gonadotropin on the expression of activin betaA and ActRIIA receptor, IBMX, forskolin and 8-Br-cAMP all significantly increased the mRNA levels of activin betaA and ActRIIA receptor. These results suggest that gonadotropin activates the activin system in the zebrafish ovary by increasing the expression of both activin and its receptors.