Redundant roles of AKT1 and AKT2 in fertility, estrous cyclicity and endometrial gland development.

In brief: The regulation of AKT in the endometrium during many cellular processes such as apoptosis and cell survival is crucial during the estrous cycle to ensure fertility. This research shows the specific function of AKT isoforms in the mouse endometrium for litter size, estrous cyclicity and endometrial gland development. Abstract: Apoptosis and cell survival regulation are crucial processes during the estrous cycle to prepare a receptive uterus during implantation for successful recognition of pregnancy. PI3K/AKT signaling has a crucial role during gestation, and AKT isoforms (1, 2 or 3) are regulated differently in the endometrium during the estrous cycle and embryo implantation. However, the specific roles of these isoforms are still unclear. We have previously shown that AKT isoforms expression during the rat estrous cycle and gestation is differently regulated. The present study aimed to establish the specific role of AKT isoforms in the mouse uterus. The hypothesis is that dysregulation of AKT isoforms expression could cause fertility-related issues in an isoform-specific manner. With four different mouse models and in-house crossbreeding, all isoforms KO combinations (single, double and triple) were obtained in progesterone receptor-expressing tissues. The results demonstrated that in absence of one or more AKT isoforms, female fertility was decreased. Mainly, we have observed smaller litter size, specifically in Akt1-2 KO mice. Additionally, we have found Akt1-2-3 KO mice to be fully infertile. Estrous cyclicity was also disrupted in Akt1-2 KO mice with longer diestrus stage. Moreover, the number of endometrial glands was decreased throughout the estrous cycle suggesting an important role in gland development for AKT1 and AKT2. Our results suggest not only specific roles between each isoform but also a partially redundant function of AKT1 and AKT2 in litter size, estrous cyclicity and endometrial gland development. This highlights the importance of AKT in the physiological regulation of mouse fertility.

Inhibition of CRM1 activity sensitizes endometrial and ovarian cell lines to TRAIL-induced cell death.

BACKGROUND: CRM1 enrichment has been shown to be indicative of invasive as well as chemoresistant tumors. On the other hand, TRAIL, a powerful and specific anti-tumoral agent, has yet to be used effectively to treat gynecological tumors in patients. In the present study, we examined if CRM1, a nuclear exporter capable of mediating protein transport, could be a relevant target to restore chemosensitivity in chemoresistant cells. We thus explored the hypothesis that CRM1-driven nuclear exclusion of tumor suppressors could lead to chemoresistance and that CRM1 inhibitors could present a novel therapeutic approach, allowing sensitization to chemotherapeutic agents. METHODS: Ovarian cancer cell lines, as well as endometrial cancer cell lines, were treated with leptomycin B (LMB), cisplatin and TRAIL, either singly or in combination, in order to induce apoptosis. Western blot and flow cytometry analysis were used to quantify caspases activation and apoptosis induction. Immunofluorescence was used to determine nuclear localization of p53. Colony formation assays were performed to determine therapeutic effectiveness; p53 siRNA were used to establish p53 role in sensitization. Additional information from GEO database and Prognoscan allowed us to contextualise the obtained results. Finally, qRT-PCR was performed to measure apoptotic regulators expression. RESULTS: TRAIL and LMB combination therapy lead to cleavage of caspase-3 as well as the appearance of cleaved-PARP, and thus, apoptosis. Further experiments suggested that sensitization was achieved through the synergistic downregulation of multiple inhibitor of apoptosis, as well as the activation of apoptotic pathways. p53 was enriched in the nucleus following LMB treatments, but did not seem to be required for sensitization; additional experiments suggested that p53 opposed the apoptotic effects of LMB and TRAIL. Results obtained from public data repositories suggested that CRM1 was a driver of chemoresistance and poor prognostic; DR5, on the other hand, acted as as a marker of positive prognostic. CONCLUSIONS: Taken together, our results suggest that the use of CRM1 inhibitors, in combination to chemotherapeutic compounds, could be highly effective in the treatment of gynecological malignancies.

Expression, activation, and role of AKT isoforms in the uterus.

The three isoforms of AKT: AKT1, AKT2, and AKT3, are crucial regulators of both normal and pathological cellular processes. Each of these isoforms exhibits a high level of homology and functional redundancy with each other. However, while being highly similar and structurally homologous, a rising amount of evidence is showing that each isoform possesses specific targets as well as preferential subcellular localization. The role of AKT has been studied extensively in reproductive processes, but isoform-specific roles are yet to be fully understood. This review will focus on the role of AKT in the uterus and its function in processes related to cell death and proliferation such as embryo implantation, decidualization, endometriosis, and endometrial cancer in an isoform-centric manner. In this review, we will cover the activation of AKT in various settings, localization of isoforms in subcellular compartments, and the effect of isoform expression on cellular processes. To fully understand the dynamic molecular processes taking place in the uterus, it is crucial that we better understand the physiological role of AKT isoforms as well as their function in the emergence of diseases.

Adjuvant Treatment of Stage I-II Serous Endometrial Cancer: A Single Institution 20-Year Experience.

Background: Serous endometrial carcinoma (SEC) is a high-risk subtype of endometrial cancer. The effectiveness of multiple adjuvant therapies, namely chemotherapy (CT), radiotherapy (RT), and sequential/concurrent chemotherapy with radiotherapy (CRT), have previously been investigated. However, optimal management of early-stage SEC remains unclarified. Methods: All cases of early-stage SEC (FIGO 2009 stages I-II) treated in our institution from 2002 to 2019 were identified. Patient data were documented until September 2023. Overall survival (OS) and disease-free survival (DFS) were computed using Kaplan-Meier estimates and Cox's proportional hazard model; descriptive statistical analysis was performed. Results: A total of 50 patients underwent total hysterectomy-bilateral salpingo-oophorectomy and omentectomy, displaying stage IA (60%), IB (24%), and II (16%) disease. The median follow-up was 90.9 months. Patients underwent adjuvant CRT (n = 36, 72%), CT (n = 6, 12%), or RT (n = 6, 12%). Two patients were observed and excluded from analyses. The 42 patients who received radiotherapy had pelvic external beam radiotherapy (n = 10), vaginal brachytherapy (n = 21), or both (n = 11). CRT had better OS (HR 0.14, 95%CI 0.04-0.52, p < 0.005) and DFS (HR 0.25, 95%CI 0.07-0.97, p = 0.05) than CT alone. RT displayed no OS or DFS benefits compared to CT/CRT. Recurrences were mostly distant. Acute and late G3-4 toxicities were primarily hematologic. Conclusions: Our data underline the challenge of treating SEC. CRT appears to be superior to CT alone but not to RT. Most recurrences were distant, highlighting the need for optimized systemic treatment options.

Radiosurgically Treated Recurrent Cerebellar Hemangioblastoma: A Case Report and Literature Review.

BACKGROUND: Cystic, sporadic hemangioblastomas (HBLs) represent a unique, therapeutically challenging subset of central nervous system tumors, mainly due to their unpredictable growth patterns and potential for symptomatic progression. This study aims to explore the complexities surrounding the diagnosis, treatment, and long-term management of these lesions. METHODS: A comprehensive literature review was performed, and a detailed case study of a 56-year-old patient with a cystic, sporadic cerebellar HBL was produced. RESULTS: The case highlights the multiphasic growth pattern typical of cystic, sporadic HBLs, characterized by periods of dormancy and subsequent rapid expansion. An initial surgical intervention offered temporary control. Tumor recurrence, mainly through cystic enlargement, was treated by SRS. A subsequent recurrence, again caused by cystic growth, eventually led to the patient's death. The intricacies of treatment modalities, focusing on the transition from surgical resection to stereotactic radiosurgery (SRS) upon recurrence, are discussed. Parameters indicating impending tumor growth, coupled with symptomatic advances, are also explored. CONCLUSIONS: The management of cystic, sporadic cerebellar HBLs requires a strategic approach that can be informed by radiological characteristics and tumoral behavior. This study underscores the importance of a proactive, individualized management plan and suggests guidelines that could inform clinical decision making.

Comparison of Weekly Paclitaxel Regimens in Recurrent Platinum-Resistant Ovarian Cancer: A Single Institution Retrospective Study.

Weekly paclitaxel (WP) is a chemotherapeutic cornerstone in the management of patients with platinum-resistant ovarian carcinoma. Multiple WP dosing regimens have been used clinically and studied individually. However, no formal comparison of these regimens is available to provide objective guidance in clinical decision making. The primary objective of this study was to compare the cumulative dose of paclitaxel delivered using 80 mg/m2/week, administered using either a 3 weeks out of 4 (WP3) or a 4 weeks out of 4 (WP4) regimen. The secondary objective was to evaluate the clinical outcomes associated with both regimens, including efficacy and toxicity parameters. Our retrospective cohort comprised 149 patients harboring platinum-resistant ovarian cancer treated at the CHU de Québec from January 2012 to January 2023. WP3 and WP4 reached a similar cumulative dose (1353.7 vs. 1404.2 mg/m2; p = 0.29). No significant differences in the clinical outcomes were observed. The frequency of dose reduction was significantly higher for WP4 than WP3 (44.7% vs. 4.9%; p < 0.01), mainly due to treatment intolerance from toxicity (34.0% vs. 3.9%; p < 0.01). Our data suggest that a WP3 regimen delivers a similar cumulative dose to WP4, hence offering a better tolerability profile without compromising efficacy.

Cisplatin-induced caspase activation mediates PTEN cleavage in ovarian cancer cells: a potential mechanism of chemoresistance.

BACKGROUND: The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) tumor suppressor protein is a central negative regulator of the PI3K/AKT signaling cascade and suppresses cell survival as well as cell proliferation. PTEN is found to be either inactivated or mutated in various human malignancies. In the present study, we have investigated the regulation of PTEN during cisplatin induced apoptosis in A2780, A270-CP (cisplatin resistant), OVCAR-3 and SKOV3 ovarian cancer cell lines. METHODS: Cells were treated with 10µM of cisplatin for 24h. Transcript and protein levels were analysed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blotting, respectively. Immunofluorescence microscopy was used to assess the intracellular localization of PTEN. Proteasome inhibitor and various caspases inhibitors were used to find the mechanism of PTEN degradation. RESULTS: PTEN protein levels were found to be decreased significantly in A2780 cells; however, there was no change in PTEN protein levels in A2780-CP, OVCAR-3 and SKOV3 cells with cisplatin treatment. The decrease in PTEN protein was accompanied with an increase in the levels of AKT phosphorylation (pAKT) in A2780 cells and a decrease of BCL-2. Cisplatin treatment induced the activation/cleavage of caspase-3, -6, -7, -8, -9 in all cell lines tested in this study except the resistant variant A2780-CP cells. In A2780 cells, restoration of PTEN levels was achieved upon pre-treatment with Z-DEVD-FMK (broad range caspases inhibitor) and not with MG132 (proteasome inhibitor) and by overexpression of BCL-2, suggesting that caspases and BCL-2 are involved in the decrease of PTEN protein levels in A2780 cells. CONCLUSION: The decrease in pro-apoptotic PTEN protein levels and increase in survival factor pAKT in A2780 ovarian cancer cells suggest that cisplatin treatment could further exacerbate drug resistance in A2780 ovarian cancer cells.

Pharmacologic inhibition of Akt in combination with chemotherapeutic agents effectively induces apoptosis in ovarian and endometrial cancer cell lines.

The PI3K/Akt signaling pathway, the most frequently altered signaling system in human cancer, is a crucial inducer of dysregulated proliferation and neoplastic processes; however, few therapeutic strategies using PI3K/Akt inhibitors singly have been shown to be effective. The purpose of this paper was to underline the potential benefit of pharmacological modulation of the PI3K/Akt pathway when combined with specific chemotherapeutic regimens. We have studied the ability of NVP-BEZ235 (PI3K/mTOR inhibitor) and AZD5363 (Akt inhibitor) in the sensitization of cancer cells to cisplatin and doxorubicin. Our results show that NVP-BEZ235 sensitizes cells preferentially to cisplatin while AZD5363 sensitizes cells to doxorubicin. At equal concentrations (5 µm), both inhibitors reduce ribosomal protein S6 phosphorylation, but AZD5363 is more effective in reducing GSK3ß phosphorylation as well as S6 phosphorylation. Additionally, AZD5363 is capable of inducing FOXO1 and p53 nuclear localization and reduces BAD phosphorylation, which is generally increased by cisplatin and doxorubicin. Finally, the combination of AZD5363 and doxorubicin induces apoptosis in cells and robustly reduces cell ability to clonally replicate, which underlines a potential cooperative effect of the studied compounds.

Regulation of the PI3K/Akt pathway during decidualization of endometrial stromal cells.

Infertility is constantly increasing in Canada, where 16% of Canadian couples are experiencing difficulty conceiving. It is thought that infertility can emanate from the dysregulated communication between the embryo and the maternal endometrium. In order to allow for this window of implantation to be open at the right moment, endometrial stromal cells proliferate and differentiate by a mechanism called decidualization. Intracellular and molecular mechanisms involved in the regulation of apoptosis and cell proliferation during decidualization of the endometrium are yet to be fully understood. It has been well demonstrated previously that Akt is importantly involved in cell survival and glycogen synthesis. Akt1, Akt2 and Akt3 isoforms have distinct physiological roles; this could also be the case during decidualization and pregnancy. The aim of this study is to investigate the regulation of PI3K/Akt pathway during the decidualization process of endometrial stromal cells. Expression of Akt isoforms, Akt activity (phospho-Akt), pIκB and substrates of Akt during decidualization were measured. To our knowledge, these results are the first to suggest a decrease in levels of Akt isoforms as well as a downregulation of Akt activity in the process of decidualization of human endometrial stromal cells. We also uncovered that decidualization induced nuclear localization of p65 through the phosphorylation of IκB, its inhibitory subunit; however, Par-4, a recently uncovered regulator of cell differentiation, was displaced from the nucleus upon decidualization. Our results also suggest that HIESC cells exhibit decreased motility during decidualization and that PI3K pathway inhibition could be involved in this process. Finally, we demonstrate that specific Akt isoforms present unique effects on the successful induction of decidualization. Further analyses will involve investigations to understand the precise signaling mechanisms by which this pathway is regulated.

Post-translational regulation of the cleaved fragment of Par-4 in ovarian and endometrial cancer cells.

We recently reported the caspase3-dependent cleavage of Par-4 resulting in the accumulation of a 25kDa cleaved-Par-4 (cl-Par-4) fragment and we investigated in the present study the mechanisms regulating this fragment using cl-Par-4-expressing stable clones derived from ovarian and endometrial cancer cell lines.Cl-Par-4 protein was weakly express in all stable clones despite constitutive expression. However, upon cisplatin treatment, cl-Par-4 levels increased up to 50-fold relative to baseline conditions. Treatment of stable clones with proteasome and translation inhibitors revealed that cisplatin exposure might in fact protect cl-Par-4 from proteasome-dependent degradation. PI3K and MAPK pathways were also implicated as evidenced by an increase of cl-Par-4 in the presence of PI3K inhibitors and a decrease using MAPK inhibitors. Finally using bioinformatics resources, we found diverse datasets showing similar results to those we observed with the proteasome and cl-Par-4 further supporting our data.These new findings add to the complex mechanisms regulating Par-4 expression and activity, and justify further studies addressing the biological significance of this phenomenon in gynaecological cancer cells.