In vitro and in vivo effects of MK2206 and chloroquine combination therapy on endometriosis: autophagy may be required for regrowth of endometriosis

The "Road" to Malignant Transformation from Endometriosis to Endometriosis-Associated Ovarian Cancers (EAOCs): An mTOR-Centred Review

Ovarian cancer is an umbrella term covering a number of distinct subtypes. Endometrioid and clear-cell ovarian carcinoma are endometriosis-associated ovarian cancers (EAOCs) frequently arising from ectopic endometrium in the ovary. The mechanistic target of rapamycin (mTOR) is a crucial regulator of cellular homeostasis and is dysregulated in both endometriosis and endometriosis-associated ovarian cancer, potentially favouring carcinogenesis across a spectrum from benign disease with cancer-like characteristics, through an atypical phase, to frank malignancy. In this review, we focus on mTOR dysregulation in endometriosis and EAOCs, investigating cancer driver gene mutations and their potential interaction with the mTOR pathway. Additionally, we explore the complex pathogenesis of transformation, considering environmental, hormonal, and epigenetic factors. We then discuss postmenopausal endometriosis pathogenesis and propensity for malignant transformation. Finally, we summarize the current advancements in mTOR-targeted therapeutics for endometriosis and EAOCs.

Research progress in rodent models of endometriosis

Endometriosis is a common and frequent disease in gynecology; its etiology and pathogenesis are partially understood and still not clear. The construction of suitable animal models is beneficial for basic research related to the disease. Currently, rodents have the advantages of low cost, fast reproduction, easy rearing, and a similar endometrial structure to humans. Depending on the purpose of the experiment, different molding methods have their advantages. In this paper, we describe the traditional methods of constructing endometriosis rodent models, compare their advantages and disadvantages, and introduce newly developed rodent models, such as cell line injection models, pain models, genetically engineered mouse models, fluorescent tracer models, iron overload models, chemical induction models, and methods of constructing rodent models of different subtypes of endometriosis. Fertility and treatment of endometriosis rodent models are also described. This study provides a reference for researchers in the selection of animal models for pathogenesis and drug treatment studies.

CircFOXO3 mediates hypoxia-induced autophagy of endometrial stromal cells in endometriosis

Endometriosis is a benign gynecological disease that shares some common features of malignancy. Autophagy plays vital roles in endometriosis and influences endometrial cell metastasis, and hypoxia was identified as the initiator of this pathological process through hypoxia inducible factor 1 alpha (HIF-1α). A newly discovered circular RNA FOXO3 (circFOXO3) is critical in cell autophagy, migration, and invasion of various diseases and is reported to be related to hypoxia, although its role in endometriosis remains to be elucidated up to now. In this study, a lower circFOXO3 expression in ectopic endometrium was investigated. Furthermore, we verified that circFOXO3 could regulate autophagy by downregulating the level of p53 protein to mediate the migration and invasion of human endometrial stromal cells (T HESCs). Additionally, the effects of HIF-1α on circFOXO3 and autophagy were examined in T HESCs. Notably, overexpression of HIF-1α could induce autophagy and inhibit circFOXO3 expression, whereas overexpressing of circFOXO3 under hypoxia significantly inhibited hypoxia-induced autophagy. Mechanistically, the direct combination between HIF-1α and HIF-1α-binding site on adenosine deaminase 1 acting on RNA (ADAR1) promoter increased the level of ADAR1 protein, which bind directly with circFOXO3 pre-mRNA to block the cyclization of circFOXO3. All these results support that hypoxia-mediated ADAR1 elevation inhibited the expression of circFOXO3, and then autophagy was induced upon loss of circFOXO3 via inhibition of p53 degradation, participating in the development of endometriosis.

Molecular mechanism of autophagy and apoptosis in endometriosis: Current understanding and future research directions

Background

Endometriosis is a common gynecological condition, with symptoms including pain and infertility. Regurgitated endometrial cells into the peritoneal cavity encounter hypoxia and nutrient starvation. Endometriotic cells have evolved various adaptive mechanisms to survive in this inevitable condition. These adaptations include escape from apoptosis. Autophagy, a self-degradation system, controls apoptosis during stress conditions. However, to date, the mechanisms regulating the interplay between autophagy and apoptosis are still poorly understood. In this review, we summarize the current understanding of the molecular characteristics of autophagy in endometriosis and discuss future therapeutic challenges.

Methods

A search of PubMed and Google Scholar databases were used to identify relevant studies for this narrative literature review.

Results

Autophagy may be dynamically regulated through various intrinsic (e.g., PI3K/AKT/mTOR signal transduction network) and extrinsic (e.g., hypoxia and iron-mediated oxidative stress) pathways, contributing to the development and progression of endometriosis. Upregulation of mTOR expression suppresses apoptosis via inhibiting the autophagy pathway, whereas hypoxia or excess iron often inhibits apoptosis via promoting autophagy.

Conclusion

Endometriotic cells may have acquired antiapoptotic mechanisms through unique intrinsic and extrinsic autophagy pathways to survive in changing environments.

Linc-ROR Promotes EMT by Targeting miR-204-5p/SMAD4 in Endometriosis

Endometriosis (EMs) is a systemic and chronic disease with cancer-like feature, namely, distant implantation, which caused heavy healthy burden of nearly 200 million females. LncRNAs have been proved as new modulators in epithelial-mesenchymal transition (EMT) and EMs. Quantitative real-time PCR was conducted to measure the expression level of long intergenic non-protein coding RNA, regulator of reprogramming (Linc-ROR), and miR-204-5p in ectopic endometrium (n = 25), eutopic endometrium (n = 20), and natural control endometrium (n = 22). Overexpression of Linc-ROR, knockdown or overexpression of miR-204-5p in End1/E6E7 and Ishikawa cells, was conducted to detect the function of Linc-ROR and miR-204-5p in EMs. Furthermore, luciferase reports were used to confirm the combination of Linc-ROR and miR-204-5p and the combination between miR-204-5p and SMAD4. Cell-Counting Kit-8, EdU assay, transwell assays, and Western blotting were used to detect the function of Linc-ROR and miR-204-5p in EMs cancer-like behaviors and EMT process. Linc-ROR was up-regulated in ectopic endometrium. Overexpressed Linc-ROR promotes cell proliferation, invasion, and EMT process. Linc-ROR regulated the EMT process, cellular proliferation, and invasion of EMs via binding to miR-204-5p. In addition, overexpression of Linc-ROR up-regulated SMAD4, a target protein of miR-204-5p, with which regulated EMT process and cancer-like behaviors in EMs together. Linc-ROR/miR-204-5p/SMAD4 axis plays a vital role in regulation EMT process in EMs, which might become a novel therapeutic targets and powerful biomarkers in EMs therapy.

Impaired secretion of C-X-C motif chemokine ligand 10 by stimulation with a Toll-like receptor 4 ligand in endometrial epithelium of infertile patients with minimal-to-mild endometriosis

Successful embryo implantation requires transient, well-controlled inflammation in decidualizing cells. In mice, Toll-like receptor (TLR) 4 signaling in endometrial epithelial cells (EECs) by stimulation with factors present in seminal fluids has been shown to be a key upstream driver of a controlled inflammatory response. Clinical evidence supports that exposure of the female reproductive tract to seminal plasma promotes implantation success. We investigated the response of EECs to TLR2 (Pam3Csk4), TLR 3 (Poly I:C), and TLR4 (lipopolysaccharides [LPS]) ligands with respect to secretion of C-X-C motif chemokine ligand (CXCL) 10 (CXCL10) and interleukin-6 (IL-6) in infertile patients with minimal-to-mild endometriosis (EECs-endo) (n = 38) and those of healthy, fertile women (EECs-healthy) (n = 30). Stimulation with either Pam3Csk4, Poly I:C or LPS, significantly induced CXCL10 and IL-6 in EECs-healthy (p < 0.05). In EECs-endo, either Pam3Csk4 or Poly I:C significantly induced CXCL10 (p < 0.05), whereas no significant response was observed after stimulation with LPS. Neither LPS, Poly I:C, nor Pam3Csk4 significantly induced IL-6 secretion in EECs-endo. Secretion of CXCL10 in EECs-healthy after stimulation with LPS was significantly higher (p < 0.05) than that in EECs-endo. CXCL10 decreased cell proliferation of EECs from both groups. Activation of nuclear factor kappa light chain enhancer of activated B cells and signal transducer and activator of transcription 3 signalings was not impaired, but activation of p38 mitogen-activated protein kinases signaling by LPS stimulation was impaired in EECs-endo. The present findings suggested that an insufficient response of EECs to a TLR4 ligand may be involved in molecular mechanisms of endometriosis-associated infertility.

Identification of a Novel Cuproptosis-Related Gene Signature in Eutopic Endometrium of Women with Endometriosis

Endometriosis (EMs) is a life-long endocrine disorder and a common cause for female infertility and pelvic pain. The key characteristics of eutopic endometrium of EMs patients are high proliferative and migratory potentials. Cuproptosis is a recently identified copper- and-mitochondrial-dependent regulated cell death. Regretfully, its role in EMs remains unclear. In this study, Kyoto Encyclopedia of Genes and Genomes analyses of differentially expressed genes (DEGs) indicated strong activation of the PI3K-Akt-mTOR pathway and biological process analysis reported positive regulation of kinase activity. Next, we screened 11 cuproptosis-related DEGs and found all of them were downregulated in the EMs group, which indicated the suppression of cuproptosis in EMs. One key cuproptosis-related gene, PDHA1, was selected via support vector machine, random forest algorithm and lasso regularization to build a risk-scoring model, which was tested in both internal and external validations. In conclusion, the downregulation and kinase activity of PDHA1 may function with the PI3K-Akt-mTOR pathway in some way, which could suppress the cuproptosis level and account for the cancer-like pathology in EMs.

IL-10 is not anti-fibrotic but pro-fibrotic in endometriosis: IL-10 treatment of endometriotic stromal cells in vitro promotes myofibroblast proliferation and collagen type I protein expression

STUDY QUESTION

Is interleukin-10 (IL-10) anti-fibrotic in endometriosis?

SUMMARY ANSWER

IL-10 is not anti-fibrotic but pro-fibrotic in endometriosis, because IL-10 treatment of endometriotic stromal cells in vitro promotes myofibroblast proliferation and collagen type I protein expression.

WHAT IS KNOWN ALREADY

We previously showed that persistent activation of signal transducer and activator of transcription 3 (STAT3) via IL-6 trans-signaling promotes fibrosis of endometriosis. Studies showed marked anti-fibrotic effects of IL-10 via the STAT3 signaling pathway, which is generally considered to be anti-inflammatory, in various organs.

STUDY DESIGN, SIZE, DURATION

Endometrial and/or endometriotic samples of 54 patients who had histological evidence of deep endometriosis, and endometrial samples from 30 healthy fertile women were analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The effects of IL-10/STAT3 signaling as well as inhibition of STAT3 activation by knockdown of STAT3 gene on the pro-fibrotic phenotype in endometrial and endometriotic stromal cells in vitro were investigated. Then, the effects of various time points of IL-10 treatment in combination with transforming growth factor (TGF)-β1 and/or IL-6/soluble IL-6 receptor (sIL-6R) on the profibrotic phenotype of endometrial and endometriotic stromal cells were investigated.

MAIN RESULTS AND THE ROLE OF CHANCE

IL-10 induced pro-fibrotic phenotype (cell proliferation, collagen type I synthesis, α-smooth muscle actin positive stress fibers and collagen gel contraction) of endometriotic stromal cells. Knockdown of STAT3 gene decreased the IL-10 induced pro-fibrotic phenotype of endometriotic stromal cells. In contrast, IL-10 had no significant effects on pro-fibrotic phenotype of endometrial stromal cells of healthy women. Sequential IL-10 treatment with or without TGF-β1 and/or IL-6/sIL-6R induced persistent activation of STAT3 and significantly increased proliferation of myofibroblasts (cells with α-smooth muscle actin positive stress fibers) and protein expression of collagen type I in endometriotic stromal cells. TGF-β1 and/or IL-6/sIL6RIL-6/sIL6R treatment significantly increased tissue inhibitor of metalloproteinase 1 (TIMP1) protein expression, whereas IL-10 had no significant effects. Knockdown of STAT3 gene significantly decreased the TGF-β1 and/or IL-6/sIL6R induced TIMP1 protein expression. In contrast, pre-treatment with IL-10 before TGF-β1 and/or IL-6/sIL-6R treatment and sequential IL-10 treatment with or without TGF-β1 and/or IL-6/sIL-6R significantly decreased proliferation of fibroblasts (cells without α-smooth muscle actin positive stress fibers) and collagen type I protein expression in endometrial stromal cells of healthy women.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Given the large number of complex interactions and signaling pathways of pro- and anti-inflammatory mediators that are involved in the pathophysiology of endometriosis, the present study investigated only a very small portion of the whole. Further in vivo studies are required to validate the present findings.

WIDER IMPLICATIONS OF THE FINDINGS

Inflammatory mediators in the pathophysiology of endometriosis have been extensively investigated as potential therapeutic targets. However, the present study showed that anti-inflammatory signals of IL-10 and IL-6 through persistent STAT3 activation may promote endometriosis fibrosis. Therapeutic strategies, such as suppression of 'inflammation', might dysregulate the cross-regulation of 'pro- and anti-inflammatory mediators', leading to detrimental effects in patients with endometriosis, such as fibrosis. To develop new, but not deleterious, therapeutic strategies, studies are required to investigate whether, how and what 'anti-inflammatory mediators' along with pro-inflammatory mediators are involved in individual patients with endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported in part by KARL STORZ SE & Co. KG (Tuttlingen, Germany). The authors have no conflict of interest to disclose.

Deficiency of MST1 in endometriosis related peritoneal macrophages promoted the autophagy of ectopic endometrial stromal cells by IL-10

Changes in the function of peritoneal macrophages contribute to the homeostasis of the peritoneal immune microenvironment in endometriosis. The mechanism by which ectopic tissues escape phagocytic clearance by macrophages to achieve ectopic colonization and proliferation is unknown. The expression of CD163 in peritoneal macrophages in patients with endometriosis is increased, with the overexpression of MAPK, which can promote the M2-type polarization of macrophages and reduce their ability to phagocytose ectopic endometrial cells. As an upstream regulator of MAPK, MST1 expression is deficient in peritoneal macrophages of patients with endometriosis. This process is regulated by miR-887-5p, a noncoding RNA targeting MST1. Moreover, MST1-knockout macrophages secrete anti-inflammatory factor IL-10, which promotes autophagy of ectopic endometrial stromal cells. These results suggest that MST1 deficient macrophages may accelerate the autophagy of ectopic endometrium via IL-10 which was regulated by miR-887-5p.

Role of AMPK/mTOR, mitochondria, and ROS in the pathogenesis of endometriosis

Endometriosis is the presence of endometrial tissue outside the uterine cavity usually in the ovaries, fallopian tube, and pelvic cavity. It's a chronic enigmatic gynecological condition associated with dysmenorrhea, dyspareunia, pelvic pain, and infertility. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, and oxidative stress. This environment promotes cell survival through the binding of membrane receptors and subsequent cascading activation of intracellular kinases that stimulate a cellular response. In endometriosis, well-established signaling pathways, mTOR and AMPK, are altered via steroid hormones and other factors to promote cell growth, migration, and proliferation. This is accompanied by dysfunction in the mitochondria that increase energy production to sustain proliferation demands consequently leading to reactive oxygen species overproduction. This review aims to summarize the role of altered mTOR/AMPK signaling pathway, mitochondrial dysfunction, and reactive oxygen species overproduction along with providing therapeutic and diagnostic approaches. Highlighting these factors would provide a better understanding to reach a coherent theory for the pathogenesis of endometriosis.

Hyaluronic Acid-Modified Nanoplatforms as a Vector for Targeted Delivery of Autophagy-Related Gene to the Endometriotic Lesions in Mice

This investigation probed endometriosis treatment using targeted nanoparticles (NPs) to modulate autophagic activity. To that end, a novel form of polymer-based NP gene delivery platform consisting of polyethyleneimine (PEI) conjugated to stearic acid (SA) and nucleotides (DNA/siRNAs) and enclosed by hyaluronic acid (HA) was prepared. CD44 is highly upregulated in cystic lesions, and HA–CD44 binding in this specific nanoplatform was used to achieve targeted drug delivery to CD44-expression endometriotic tissues. The expression of autophagy-related genes was modulated to explore the importance of this process in the development of endometriosis. By inducing autophagic activity, we were able to reduce the size of endometriotic cysts and suppress the development of ectopic endometrium. To further confirm the relationship between autophagic activity and this disease in humans and animals, numbers of autophagic vesicles and autophagic protein expression were assessed in lesion tissue samples from patients, revealing there may be consistency between animal and human data. Overall, these data revealed the ability of this (PEI–SA/DNA) HA gene delivery system to regulate autophagic activity and, thereby, aid in the treatment of endometriosis.

Ribosome Biogenesis Serves as a Therapeutic Target for Treating Endometriosis and the Associated Complications

Ribosome biogenesis is a cellular process critical for protein homeostasis during cell growth and multiplication. Our previous study confirmed up-regulation of ribosome biogenesis during endometriosis progression and malignant transition, thus anti-ribosome biogenesis may be effective for treating endometriosis and the associated complications. A mouse model with human endometriosis features was established and treated with three different drugs that can block ribosome biogenesis, including inhibitors against mTOR/PI3K (GSK2126458) and RNA polymerase I (CX5461 and BMH21). The average lesion numbers and disease frequencies were significantly reduced in treated mice as compared to controls treated with vehicle. Flow cytometry analyses confirmed the reduction of small peritoneal macrophage and neutrophil populations with increased large versus small macrophage ratios, suggesting inflammation suppression by drug treatments. Lesions in treated mice also showed lower nerve fiber density which can support the finding of pain-relief by behavioral studies. Our study therefore suggested ribosome biogenesis as a potential therapeutic target for treating endometriosis.

ACE2 pathway regulates thermogenesis and energy metabolism

Identification of key regulators of energy homeostasis holds important therapeutic promise for metabolic disorders, such as obesity and diabetes. ACE2 cleaves angiotensin II (Ang II) to generate Ang-(1-7) which acts mainly through the Mas1 receptor. Here, we identify ACE2 pathway as a critical regulator in the maintenance of thermogenesis and energy expenditure. We found that ACE2 is highly expressed in brown adipose tissue (BAT) and that cold stimulation increases ACE2 and Ang-(1-7) levels in BAT and serum. Ace2 knockout mice (Ace2^-/y) and Mas1 knockout mice (Mas1^-/-) displayed impaired thermogenesis. Mice transplanted with brown adipose tissue from Mas1^-/- display metabolic abnormalities consistent with those seen in the Ace2 and Mas1 knockout mice. In contrast, impaired thermogenesis of Lepr^db/db obese diabetic mice and high-fat diet-induced obese mice were ameliorated by overexpression of Ace2 or continuous infusion of Ang-(1-7). Activation of ACE2 pathway was associated with improvement of metabolic parameters, including blood glucose, lipids, and energy expenditure in multiple animal models. Consistently, ACE2 pathway remarkably enhanced the browning of white adipose tissue. Mechanistically, we showed that ACE2 pathway activated Akt/FoxO1 and PKA pathway, leading to induction of UCP1 and activation of mitochondrial function. Our data propose that adaptive thermogenesis requires regulation of ACE2 pathway and highlight novel potential therapeutic targets for the treatment of metabolic disorders.

Autophagy as a Therapeutic Target of Natural Products Enhancing Embryo Implantation

Infertility is an emerging health issue worldwide, and female infertility is intimately associated with embryo implantation failure. Embryo implantation is an essential process during the initiation of prenatal development. Recent studies have strongly suggested that autophagy in the endometrium is the most important factor for successful embryo implantation. In addition, several studies have reported the effects of various natural products on infertility improvement via the regulation of embryo implantation, embryo quality, and endometrial receptivity. However, it is unclear whether natural products can improve embryo implantation ability by regulating endometrial autophagy. Therefore, we performed a literature review of studies on endometrial autophagy, embryo implantation, natural products, and female infertility. Based on the information from these studies, this review suggests a new treatment strategy for female infertility by proposing natural products that have been proven to be safe and effective as endometrial autophagy regulators; additionally, we provide a comprehensive understanding of the relationship between the regulation of endometrial autophagy by natural products and female infertility, with an emphasis on embryo implantation.

Pharmaceuticals targeting signaling pathways of endometriosis as potential new medical treatment: A review

Endometriosis (EM) is defined as endometrial tissues found outside the uterus. Growth and development of endometriotic cells in ectopic sites can be promoted via multiple pathways, including MAPK/MEK/ERK, PI3K/Akt/mTOR, NF-κB, Rho/ROCK, reactive oxidative stress, tumor necrosis factor, transforming growth factor-β, Wnt/β-catenin, vascular endothelial growth factor, estrogen, and cytokines. The underlying pathophysiological mechanisms include proliferation, apoptosis, autophagy, migration, invasion, fibrosis, angiogenesis, oxidative stress, inflammation, and immune escape. Current medical treatments for EM are mainly hormonal and symptomatic, and thus the development of new, effective, and safe pharmaceuticals targeting specific molecular and signaling pathways is needed. Here, we systematically reviewed the literature focused on pharmaceuticals that specifically target the molecular and signaling pathways involved in the pathophysiology of EM. Potential drug targets, their upstream and downstream molecules with key aberrant signaling, and the regulatory mechanisms promoting the growth and development of endometriotic cells and tissues were discussed. Hormonal pharmaceuticals, including melatonin, exerts proapoptotic via regulating matrix metallopeptidase activity while nonhormonal pharmaceutical sorafenib exerts antiproliferative effect via MAPK/ERK pathway and antiangiogenesis activity via VEGF/VEGFR pathway. N-acetyl cysteine, curcumin, and ginsenoside exert antioxidant and anti-inflammatory effects via radical scavenging activity. Natural products have high efficacy with minimal side effects; for example, resveratrol and epigallocatechin gallate have multiple targets and provide synergistic efficacy to resolve the complexity of the pathophysiology of EM, showing promising efficacy in treating EM. Although new medical treatments are currently being developed, more detailed pharmacological studies and large sample size clinical trials are needed to confirm the efficacy and safety of these treatments in the near future.

The Multifaceted Role of Autophagy in Endometrium Homeostasis and Disease

Autophagy is a conserved fundamental cellular process with a primary function of catabolizing harmful or surplus cellular contents such as protein aggregates, dysfunctional/long-lived organelles, intracellular pathogens, and storage nutrients. An increasing body of evidence reveals that basal autophagy is essential for maintaining endometrial homeostasis and mediating endometrial-specific functions, including menstrual cycle, embryo implantation, and decidualization. However, perturbed levels of autophagy can lead to severe endometrial pathologies, including endometriosis, endometrial hyperplasia, endometrial cancer, adenomyosis, and leiomyoma. This review highlights the most recent findings on the activity, regulation, and function of autophagy in endometrium physiology and pathology. Understanding the mechanistic roles of autophagy in endometrium homeostasis and disease is key to developing novel therapeutic strategies for endometrium-related infertility and malignancies.

The Potential Effect of Fucoidan on Inhibiting Epithelial-to-Mesenchymal Transition, Proliferation, and Increase in Apoptosis for Endometriosis Treatment: In Vivo and In Vitro Study

Endometriosis is common in reproductive-age women and its pathology is to increase proliferation and migration to enhance epithelial-to-mesenchymal transition progression (EMT). However, treatments are currently limited, so it is important to explore new therapeutic drugs. Hence, in this study, we investigate the therapeutic effect of fucoidan (FC) on the progression and mechanisms of endometriosis. The cell viability of endometrial cell lines End1/E6E7 and Vk2/E6E7 treated with different concentrations of FC were assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell counting. Cell migration was evaluated using wound-healing assay. In an in vivo experiment, female Balb/c mice received surgically induced endometriosis followed by different concentrations of fucoidan for 6 weeks. High-frequency ultrasound imaging was applied to detect subsequent lesion growth. The results demonstrated that fucoidan inhibited the viability and migration ability of End1/E6E7 and Vk2/E6E7 cells. Additionally, the administration of fucoidan reduced the volume and weight of endometriotic lesions, decreased inflammatory cytokines and vascular endothelial growth factor (VEGF) of serum and lesions, and improved EMT proliferation and apoptosis-related protein expression. For the first time, fucoidan indicated anti-proliferative and anti-inflammatory effects as well as inhibited EMT progression and induced apoptosis, improving endometriosis.

Impaired pathogen-induced autophagy and increased IL-1β and TNFα release in response to pathogenic triggers in secretory phase endometrial stromal cells of endometriosis patients

RESEARCH QUESTION

It is not clear whether innate immunity along with autophagy is altered in endometrial cells of patients with endometriosis.

DESIGN

This study evaluated the effects of lipopolysaccharide (LPS) or polyinosinic:polycytidylic acid (poly I:C) stimulation on autophagy induction, pro-IL-1β expression, and secretion of interleukin-1β (IL-1β) and tumour necrosis factor-α (TNFα) in endometrial epithelial and/or stromal cells of patients with endometriosis (EE-endo, ES-endo, respectively), those of patients with hydrosalpinx (EE-hydro, ES-hydro, respectively) and those of healthy fertile women (EE-healthy, ES-healthy, respectively), with and without inhibition of autophagy by autophagy-related (ATG)13 gene small interfering RNA (siRNA).

RESULTS

Stimulation with either LPS or poly I:C triggered autophagy in EE/ES-healthy, whereas no significant induction was observed in either EE/ES-endo or EE/ES-hydro. In EE- and/or ES-healthy, IL-1β and/or TNFα secretion after stimulation with LPS or poly I:C was significantly higher in cells with ATG13 knockdown compared with those with siRNA control (P < 0.03), whereas no significant difference was observed in either EE/ES-endo or EE/ES-hydro. In the secretory phase ES-endo without autophagy inhibition, IL-1β and TNFα secretion were significantly higher compared with those of ES-healthy after stimulation with either LPS or poly I:C for 4 h (P < 0.001) and for 24 h (P < 0.01).

CONCLUSION

Pathogen-induced autophagy was impaired in EE/ES-endo. Increased IL-1β and TNFα release in response to pathogenic triggers in the secretory phase ES-endo may result in the development of an inflammatory uterine microenvironment detrimental to successful embryo implantation.

PI3K/AKT pathway is altered in the endometriosis patient's endometrium and presents differences according to severity stage

Based on the inflammatory nature and hormone-dependency of endometriosis, PI3K/AKT signaling appears to influence its progression. Could the endometriosis stages be linked to differential changes in PI3K/AKT pathway regulation? The objective is to evaluate the expression of PI3K, PTEN, AKT and p-AKT in endometrial human biopsies, according to the presence or absence of the disease, and to assess the underlying differences regarding the endometriosis stages. Biopsy specimens of the ectopic and eutopic endometrium were obtained from twenty women with untreated peritoneal endometriosis as well as endometrium biopsies from nine controls. Our study revealed an increased expression of PI3K in eutopic and ectopic endometrium from patients with endometriosis, and a reduced expression of PTEN and increased levels of AKT phosphorylation, compared to control endometrium. Both eutopic and ectopic endometrium from patients with minimal-mild endometriosis expressed a significant reduced PTEN level compared to the respective endometrium from patients with moderate-severe endometriosis. The ratio p-AKT/total AKT showed higher levels of AKT phosphorylation in endometriotic tissue from patients with minimal-mild endometriosis. This study has firmly confirmed the alteration in PI3K/AKT pathway regulation and demonstrated clear differences between the stages of endometriosis, emphasizing the importance of this pathway in the first stage of the disease.

Discovery of novel akt1 inhibitor induces autophagy associated death in hepatocellular carcinoma cells

In this study, a series of thieno [2,3-d]pyrimidine derivatives were designed, synthesized and evaluated as novel AKT1 inhibitors. In vitro antitumor assay results showed that compounds 9d-g and 9i potently suppressed the enzymatic activities of AKT1 and potently inhibited the proliferation of HepG2, Hep3B, Huh-7 and SMMC-7721 cancer cell lines. Among these derivatives, the compound 9f demonstrated the best inhibitory activities on AKT1 (IC50 = 0.034 μM) and Huh-7 cell (IC50 = 0.076 μM). A panel of biological assays showed that compound 9f suppressed the cellular proliferation of Huh-7 through Akt/mTOR signaling pathway mediated autophagy mechanism. Furthermore, the antitumor capacity of 9f was validated in the subcutaneous Huh-7 xenograft models. Together, our results demonstrate that a novel small-molecule Akt1 inhibitor induces autophagy associated death in hepatocellular carcinoma, which may afford a potential drug candidate for targeted cancer therapy.

Endometriosis Triggers Excessive Activation of Primordial Follicles via PI3K-PTEN-Akt-Foxo3 Pathway

CONTEXT

The ovarian reserve is reduced in patients with endometriosis. We hypothesize that the phosphatidylinositol 3-kinase (PI3K)-phosphatase and tensin homolog deleted on chromosome 10 (PTEN) Akt-Forkhead box O (Foxo3) pathway is involved in reducing the ovarian reserve.

OBJECTIVE

To elucidate the signaling mechanism by which endometriosis decreases ovarian reserve.

DESIGN

Studies were conducted by using a mouse model for endometriosis and human ovaries. The endometriosis mouse model was established and ammonium trichloro (dioxoethylene-o,o') tellurate (AS101), an inhibitor of PI3K-PTEN-Akt pathway, was administered to experimental mice. Human ovaries were collected during surgery from patients with endometrioma or from patients with no ovarian pathology (control ovaries). The number of follicles and expression of Foxo3, PTEN, phosphorylated mammalian target of rapamycin and phosphorylated Akt by oocytes in primordial follicles in mouse and human ovaries were detected by immunohistochemical staining and evaluated.

RESULTS

In the endometriosis mouse model, the proportion of primordial follicles was diminished, and the proportion of primary, secondary, antral, and growing follicles was increased in comparison with controls. In both mouse and human ovaries, the PI3K-PTEN-Akt-Foxo3 pathway was activated in samples from endometriosis. Administration of AS101 restored the proportion of primordial follicles in endometriotic mice ovaries to control levels.

CONCLUSIONS

The current study describes the excessive activation of primordial follicles and the role of the PI3K-PTEN-Akt-Foxo3 pathway in the reduction of ovarian reserve associated with endometriosis. Our results suggest that a PI3K-PTEN-Akt inhibitor should be considered for further investigation as promising medicines for the prevention of the ovarian reserve reduction in patients with endometriosis.

A phase I trial of MK-2206 and hydroxychloroquine in patients with advanced solid tumors

PURPOSE

Given the evidence that coordinate inhibition of AKT induces autophagy, we studied the combination of the AKT inhibitor, MK-2206 with hydroxychloroquine (HCQ) in patients with advanced solid tumors.

METHODS

Patients were treated with weekly MK-2206 (135 mg or 200 mg) plus HCQ (200 mg, 400 mg or 600 mg BID).

RESULTS

Thirty-five patients were enrolled across 5 dose levels. Two DLTs of grade 3 maculo-papular rash were observed at dose level 2 (MK-2206 200 mg weekly plus HCQ at 400 mg BID) and 1 DLT of grade 3 fatigue at dose level 2B (MK-2206 135 mg weekly plus HCQ 600 mg BID). The maximum tolerated dose (MTD) was declared as dose level 2B. The most common adverse events attributed to MK-2206 were hyperglycemia (N = 18; 51%), fatigue (N = 17; 49%), maculo-papular rash (N = 16; 46%), diarrhea (N = 12; 34%), anorexia (N = 11; 31%), and nausea (N = 11; 31%). Patients experiencing adverse events attributed to HCQ were small in number (N = 13) and primarily included fatigue (N = 5; 14%) and maculo-papular rashes (N = 3; 9%). Statistically significant effects on the pharmacokinetic properties of MK-2206 were observed in combination with HCQ. In addition, the plasma concentrations of HCQ in the combination with MK-2206 were significantly higher than the plasma levels of HCQ as monotherapy in prior studies. The best overall response of stable disease was observed in 5/34 (15%) patients.

CONCLUSION

The combination of MK-2206 and hydroxychloroquine was tolerable, but with substantial number of drug-related AEs and minimal evidence of antitumor activity.

Role of Endometrial Autophagy in Physiological and Pathophysiological Processes

Endometrium is the mucosal lining of the uterus which expressed a cyclic process of proliferation, secretion and scaling under the control of hormones secreted by the ovary, and it also plays an indispensable role in the embryo implantation, the constitution of fetal-maternal interface, and the maintaining of pregnancy. In pathophysiological conditions, the abnormality or disorder of endometrium may lead to endometrium-related diseases, such as endometriosis, endometrium hyperplasia and even endometrial carcinoma. In recent years, more and more evidence revealed that autophagy exists in both the endometrium stroma cells and epithelial cells, and the activity of autophagy is changed in the different phases of menstruation, as well as in the endometrium-related diseases. Here, we aim to review the activity level, the regulatory factors and the function of autophagy in physiological and pathophysiological endometria, and to discuss the potential value of autophagy as a target for therapies of endometrium-related diseases.

In vitro and in vivo effects of MK2206 and chloroquine combination therapy on endometriosis: autophagy may be required for regrowth of endometriosis

BACKGROUND AND PURPOSE

A high recurrence rate after medical treatment is a major clinical problem for patients with endometriosis. Here, we have evaluated the in vitro effects of combined treatment with MK2206 (an AKT inhibitor) + chloroquine on cell growth and regrowth of endometriotic stromal cells and the in vivo effects on endometriotic implants in a mouse xenograft model of endometriosis.

EXPERIMENTAL APPROACH

We evaluated the effects of autophagy inhibition by knockdown of the ATG13, Beclin-1 and ATG12 genes and pharmacological agents (chloroquine, bafilomycin A1 or 3-methyalanine) individually and in combination with MK2206 on cell growth and/or cell regrowth of endometriotic stromal cells in vitro. Furthermore, we evaluated treatment with MK2206 + chloroquine on endometriotic implants in a mouse xenograft model of endometriosis.

KEY RESULTS

Combined treatment with MK2206 and chloroquine markedly reduced cell growth and regrowth after discontinuation of treatment in endometriotic stromal cells compared with cells treated with either drug alone. Autophagy inhibition by ATG13, Beclin-1 or ATG12 gene knockdown only affected regrowth of endometriotic stromal cells, but not endometrial stromal cells from the same patients, after a 72 h discontinuation of the combined treatment. Furthermore, combined treatment reduced the size of endometriotic implants, whereas no effects on endometriotic implants treated with either drug alone were observed in a mouse xenograft model of endometriosis.

CONCLUSIONS AND IMPLICATIONS

The present findings suggest that a novel strategy for treatment of endometriosis may involve decreasing the number of endometriotic cells that can survive treatment and then preventing regrowth by autophagy inhibition.