Ovarian toxicity of carboplatin and paclitaxel in mouse carriers of mutation in BRIP1 tumor suppressor gene.

More than 10% of women diagnosed with breast cancer during reproductive age carry hereditary germline pathogenic variants in high-penetrance BRCA genes or in others genes involved in DNA repair mechanisms such as PALB2, BRIP or ATM. Anticancer treatments may have an additional negative impact on the ovarian reserve and subsequently on the fertility of young patients carrying such mutations. Recently, the combination of carboplatin and paclitaxel is being recommended to these BRCA-mutated patients as neoadjuvant therapy. However, the impact on the ovary is unknown. Here, we investigated their effect of on the ovarian reserve using mice carriers of BRCA1-interacting protein C-terminal helicase-1 (BRIP1) mutation that plays an important role in BRCA1-dependent DNA repair. Results revealed that the administration of carboplatin or paclitaxel did not affect the ovarian reserve although increased DNA double-strand breaks were observed with carboplatin alone. Co-administration of carboplatin and paclitaxel resulted in a significant reduction of the ovarian reserve leading to a lower IVF performance, and an activation of the PI3K-Pten pathway, irrespective of the genetic background. This study suggests that co-administration of carboplatin and paclitaxel induces cumulative ovarian damage and infertility but a heterozygote genetic predisposition for DNA damage related to BRCA1 gene function does not increase this risk.

Both in vivo FSH depletion and follicular exposure to Gonadotrophin-releasing hormone analogues in vitro are not effective to prevent follicular depletion during chemotherapy in mice.

STUDY QUESTION: Does fertility preservation using gonadotrophin-releasing hormone (GnRH) analogues during chemotherapy act through a direct effect on the ovary or through inhibition of FSH secretion? SUMMARY ANSWER: The absence of FSH in vivo and the direct exposition of ovarian follicles to GnRH analogues in vitro did not prevent chemotherapy-induced ovarian damage. WHAT IS KNOWN ALREADY: The potential mechanisms of action of GnRH analogues in protecting ovaries against chemotherapy damage remain poorly understood. We previously showed that GnRH analogues have a limited inhibitory effect on gonadotropin secretion and follicular growth in mice. STUDY DESIGN SIZE, DURATION: Mouse models were developed to independently evaluate (i) the indirect effect of FSH depletion on chemotherapy-induced ovarian damage using Fshb-deficient (-/-) mice to mimic the profound inhibition of FSH secretion during GnRH analogues treatment and (ii) the direct in vitro effect of GnRH agonist and antagonist in follicles exposed to chemotherapy using a follicular culture system. PARTICIPANTS/MATERIALS, SETTING, METHODS: To assess the indirect effect of GnRH analogues through FSH inhibition, Fshb-/- mice were treated with 1 IU pregnant mare serum gonadotropin (control group) or saline (study group) for 7 days and with cyclophosphamide (200 mg/kg) on Day 5. Ovaries were collected 48 h post-cyclophosphamide to evaluate ovarian reserve, cellular apoptosis and proliferation. To evaluate the direct effects of GnRH analogues on growing follicles, isolated preantral follicles from prepubertal mice were cultured in vitro for 13 days with 1 µM GnRH analogues and 20 µM of 4-hydroperoxycyclophosphamide or not at Day 4. Oocytes were matured by adding epidermal growth factor (EGF)/hCG on Day 12. Follicular development, follicular survival, oocyte maturation rates, cAMP production, and steroidogenesis were evaluated. To assess the direct GnRH analogues effects on follicular reserve, whole neonatal ovaries were cultured in vitro under the same conditions for 2 days. Ovaries were processed 24 h post-chemotherapy for ovarian reserve, cellular apoptosis and proliferation analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Cyclophosphamide induced a significant follicular loss of more than 50% in Fshb-/- mice regardless of previous treatment with gonadotropins and no difference was observed in cell proliferation or apoptosis. In vitro experiments on growing follicles showed that 4-hydroperoxycyclophosphamide significantly decreased preantral follicle survival and maturation rates (55% and 37%, respectively) and delayed follicular development, regardless of the presence of GnRH analogues. Chemotherapy reduced granulosa cell numbers in all groups, while no change in cAMP production/106 granulosa cells was observed. Similarly, 4-hydroperoxycyclophosphamide induced apoptosis and significant follicular loss in cultured neonatal ovaries irrespective of GnRH analogues exposure. LIMITATIONS REASONS FOR CAUTION: As ovarian GnRH receptors expression differs in humans and mice, further studies are needed to validate our results in human ovaries. WIDER IMPLICATIONS OF THE FINDINGS: Our findings demonstrate that ovarian damage occurred even in the absence of FSH, suggesting that inhibition of the pituitary-gonadal axis is not involved in ovarian protection during GnRH analogues treatment. Using in vitro models, no evidence for direct protective effect of GnRH analogues against cyclophosphamide metabolite damage was observed. At present, clinical efficiency of GnRH analogues to prevent chemotherapy-induced ovarian damage remains highly debated and these experimental results reinforced the question as they did not bring evidence of direct or indirect mechanisms of protection. LARGE SCALE DATA: N/A. STUDY FUNDING AND COMPETING INTEREST(S): This work was supported by the Belgian FNRS, 'Le Fonds Emile DEFAY', and 'La Fondation Rose et Jean Hoguet'. Authors have no conflict of interest to declare.

Characterization of ß-cell plasticity mechanisms induced in mice by a transient source of exogenous insulin.

ß-Cell plasticity governs the adjustment of ß-cell mass and function to ensure normoglycemia. The study of how ß-cell mass is controlled and the identification of alternative sources of ß-cells are active fields of research. ß-Cell plasticity has been implicated in numerous physiological and pathological conditions. We developed a mice model in which we induced major ß-cell mass atrophy by implanting insulin pellets (IPI) for 7 or 10 days. The implants were then removed (IPR) to observe the timing and characteristics of ß-cell regeneration in parallel to changes in glycemia. Following IPR, the endocrine mass was reduced by 60% at day 7 and by 75% at day 10, and transient hyperglycemia was observed, which resolved within 1 wk. Five days after IPR, enhanced ß-cell proliferation and an increased frequency of small islets were observed in 7-day IPI mice. ß-Cell mass was fully restored after an additional 2 days. For the 10-day IPI group, ß-cell and endocrine mass were no longer significantly different from those of the control group at 2 wk post-IPR. Furthermore, real-time quantitative PCR analysis of endocrine structures isolated by laser capture microdissection indicated sequentially enhanced expression of the pancreatic transcription factors ß(2)/NeuroD and Pdx-1 post-IPR. Thus, our data suggest this mouse model of ß-cell plasticity not only relies on replication but also involves enhanced cell differentiation plasticity.

Biopsy of focal liver lesions: guidelines, comparison of techniques and cost-analysis.

When a focal liver lesion is discovered, differentiation between a benign and malignant nature and further characterization are mandatory to guide further treatment. Histology remains the golden standard. Improving imaging techniques such as contrast enhanced Doppler ultrasonography, spiral CT and new MRI procedures are promising, but not 100% accurate. When there is any doubt, biopsy should be performed. Fine Needle Aspiration Biopsy (FNAB) has a high sensitivity and specificity (90-95%) in experienced hands, but has a high insufficient sampling rate (up to 15%). In a series of 245 Fine Needle Tru-cut Biopsies (FNTCB) of focal solid liver lesions performed at our institution, sensitivity and specificity for the diagnosis of malignancy were 86% and 100% respectively, with an overall accuracy of 88%. Positive predictive value was 100%, but negative predictive value was rather low (56%). Insufficient sampling rate was low (2.5%), and a more accurate histological characterization was possible compared to FNAB. Finally, the cost-analysis of different biopsy techniques is presented for the Belgian situation according to used materials, pathology procedures and hospitalization.

Asymptomatic aneurysm of the hepatic artery. Management options.

Hepatic aneurysms are rare. The majority of patients present acutely with aneurysm rupture, with an attended high mortality. Diagnosis is difficult and often delayed, owing to the non-specific symptoms and lack of clinical findings. We present three cases of hepatic artery aneurysm diagnosed in a pauci- or asymptomatic stage, illustrating the different therapeutic options described when these aneurysms are diagnosed in this stage: expectant management, embolization, or surgery.