Mismatch Repair Deficiency in Adult Granulosa Cell Tumors: an Immunohistochemistry-based Preliminary Study

OBJECTIVE

Adult granulosa cell tumors (AGCTs) are rare ovarian malignant neoplasms; their etiopathogenetic mechanisms remain largely unelucidated. Lately, defects in mismatch repair (MMR) have been implicated in the pathogenesis of AGCTs. Demonstration of MMR deficiency in these tumors can help identify patients potentially eligible for immune checkpoint inhibition therapy. The present study was done to explore the role of MMR deficiency in the etiopathogenesis of AGCTs.

METHODS

This was a retrospective study conducted on histopathologically confirmed AGCT cases. MMR protein expression was evaluated by immunohistochemistry (IHC) on tissue microarrays using an antibody panel of MSH2, MSH6, MLH1, and PMS2.

RESULTS

Of a total of 40 ovarian AGCTs evaluated for MMR deficiency, none demonstrated loss of expression of any of the 4 MMR proteins.

CONCLUSIONS

The results of our preliminary study show that there is no association between MMR deficiency with AGCT. Nevertheless, larger multicenter studies are needed to confirm or refute this observation.

Estradiol Signaling at the Heart of Folliculogenesis: Its Potential Deregulation in Human Ovarian Pathologies

Estradiol (E2) is a major hormone controlling women fertility, in particular folliculogenesis. This steroid, which is locally produced by granulosa cells (GC) within ovarian follicles, controls the development and selection of dominant preovulatory follicles. E2 effects rely on a complex set of nuclear and extra-nuclear signal transduction pathways principally triggered by its nuclear receptors, ERα and ERβ. These transcription factors are differentially expressed within follicles, with ERβ being the predominant ER in GC. Several ERβ splice isoforms have been identified and display specific structural features, which greatly complicates the nature of ERβ-mediated E2 signaling. This review aims at providing a concise overview of the main actions of E2 during follicular growth, maturation, and selection in human. It also describes the current understanding of the various roles of ERβ splice isoforms, especially their influence on cell fate. We finally discuss how E2 signaling deregulation could participate in two ovarian pathogeneses characterized by either a follicular arrest, as in polycystic ovary syndrome, or an excess of GC survival and proliferation, leading to granulosa cell tumors. This review emphasizes the need for further research to better understand the molecular basis of E2 signaling throughout folliculogenesis and to improve the efficiency of ovarian-related disease therapies.

Lycium barbarum polysaccharides protect human trophoblast HTR8/SVneo cells from hydrogen peroxide‑induced oxidative stress and apoptosis

Pregnancy complications are associated with abnormal cytotrophoblast differentiation and invasion. Hydrogen peroxide (H₂O2) is an important mediator of oxidative ischemia/reperfusion stress in the placenta. Lycium barbarum polysaccharides (LBP) have been demonstrated to counteract oxidative free radicals. The effects of LBP in trophoblast HTR8/SVneo cells injured with H2O2 were examined. A cell counting kit-8 assay was performed to detect the effect of LBP at different concentrations on the proliferative ability of H2O2 injured trophoblast cells. Flow cytometry was used to determine the levels of reactive oxygen species (ROS), mitochondria membrane potential (MMP) disruption and apoptosis. Superoxide dismutase (SOD) activity and lactate dehydrogenase (LDH) leakage into the supernatant was detected by ultraviolet spectrophotometry. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were performed to detect the expression of apoptosis-associated factors, including survivin, hypoxia inducible factor 1-α (HIF1-α), Bcl-2 apoptosis regulator (Bcl-2), Bcl-2 associated X apoptosis regulator (Bax). The results revealed that LBP protected the proliferative ability of trophoblast cells injured with H2O2 in a dose-dependent manner. LBP inhibited the oxidative stress induced by H2O2, by reducing ROS and LDH levels and increasing SOD activity. Additionally, LBP decreased MMP disruption and cell apoptosis induced by H2O2, by increasing the mRNA and protein expression of survivin, HIF1-α and Bcl-2 and decreasing Bax expression. Therefore, it was concluded that LBP protected human trophoblast cells from H2O2-induced oxidative stress and cell apoptosis via regulation of apoptosis-associated factor expression. It will provide a novel strategy for the treatment of pregnancy complications.

Restoring TRAIL mediated signaling in ovarian cancer cells

Ovarian cancer has emerged as a multifaceted and genomically complex disease. Genetic/epigenetic mutations, suppression of tumor suppressors, overexpression of oncogenes, rewiring of intracellular signaling cascades and loss of apoptosis are some of the deeply studied mechanisms. In vitro and in vivo studies have highlighted different molecular mechanisms that regulate tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mediated apoptosis in ovarian cancer. In this review, we bring to limelight, expansion in understanding systematical characterization of ovarian cancer cells has led to the rapid development of new drugs and treatments to target negative regulators of TRAIL mediated signaling pathway. Wide ranging synthetic and natural agents have been shown to stimulate mRNA and protein expression of death receptors. This review is compartmentalized into programmed cell death protein 4, platelet-derived growth factor signaling and miRNA control of TRAIL mediated signaling to ovarian cancer. Mapatumumab and PRO95780 have been tested for efficacy against ovarian cancer. Use of high-throughput screening assays will aid in dissecting the heterogeneity of this disease and increasing a long-term survival which might be achieved by translating rapidly accumulating information obtained from molecular and cellular studies to clinic researches.

Ovarian granulosa cell tumors: a retrospective study of 27 cases and a review of the literature

BACKGROUND

Granulosa tumors were described for the first time in 1855 by Rokitansky. These tumors are malignancies with a relatively favorable prognosis. They are characterized by a prolonged natural history and a tendency to late recurrences. The aim of this study is to investigate the epidemiological and pathological characteristics of granulosa cell tumors and to investigate the prognosis factor for recurrences.

METHODS

The clinical data of patients who were treated in the period from January 2003 to December 2010 at the National Institute of Oncology in Rabat, Morocco for adult granulosa cell tumors of the ovary were investigated retrospectively. Data for age, clinical manifestation, imaging, diagnosis and treatment of the patients were reviewed and analyzed. Post-operative histology was obtained for all patients.

RESULTS

Twenty-seven cases were retrieved. The median patient age was 53 years. The most common clinical manifestations at diagnosis were abdominal pain and vaginal bleeding. Mean tumor size was 14 cm. The majority of patients had stage I (63%, n = 17), while (18,5%, n = 5) had stage III, (7.4%, n = 2) had stage IV, and (11%, n = 3) of patients had an unknown stage. In the follow-up period (median = 63.44 months), five (18.51%) patients relapsed. The median time to relapse was 41.8 months, (range: 18 to 62 months).

CONCLUSIONS

Granulosa cell tumor of the ovary is an uncommon neoplasm. The adult form progresses slowly and often is diagnosed in an early stage of disease. Surgery is indicated. A prolonged post-therapeutic follow-up is necessary because of the risk of recurrences, late and exceptional for the adult form.