Decidualization triggered by human endometrial stromal cells (HESCs) is a critical step in the establishment of endometrial receptivity, which provides an ideal environment for embryo implantation. However, the specific regulatory networks and core genes involved in the decidualization process remain incompletely characterized. Here, we identified ubiquitin-conjugating enzyme 2C (UBE2C), a key cell cycle regulator, as a pivotal factor in decidualization through comprehensive in vitro and in vivo investigations. RNA sequencing revealed UBE2C as a potential hub gene in the human endometrium. We found UBE2C expression was significantly downregulated in secretory-phase endometrium and in vitro decidual HESCs. Functional studies demonstrated that UBE2C overexpression attenuated decidual marker expression and disrupted normal proliferation in HESCs, mechanistically linked to NF-κB signaling pathway. Consistent with in vitro findings, mice studies showed UBE2C downregulation in peri-implantation uterine tissue, with uterine-specific UBE2C overexpression impairing both embryo implantation and decidualization. Further mechanistic exploration identified transcription factor AP-2 alpha (TFAP2A) as a novel mediator of UBE2C. Decidual stimulation promoted TFAP2A degradation via the ubiquitination pathway. Clinical relevance was established through the observation of elevated UBE2C and TFAP2A expression in secretory endometrium from recurrent implantation failure (RIF) patients. In conclusion, for endometrial decidualization and embryo implantation, TFAP2A-mediated downregulation of UBE2C is required. Dysregulation of this axis may compromise endometrial receptivity, suggesting UBE2C and TFAP2A as promising therapeutic targets for decidualization-related disorders such as RIF.

The global prevalence of infertility boosts the demands for assisted reproduction technology (ART) and medical plasticware for processing human reproductive cells. The direct exposure risks of these cells to microplastic (MPs) potentially released from the plasticware, especially when sperm is extracted by mincing testicular tissues with sharp tools, remain unknown. Also, there are methodological challenges in confirming the actual occurrence and visualizing the original morphology of MPs in the retrieved sperm samples. Here, we identified sub-10-μm polystyrene (PS) MPs with protein coronas in mechanically retrieved sperm specimens on PS plastic Petri dishes through optical photothermal infrared imaging. The particles were mainly generated by the tools that induced local polymer cutting deformation on the dishes, and a few originated from resin particles remaining on the dishes during manufacture. Each 5 mm scratch by the tools could produce 2.0-13 MPs (1.9-560 μm), depending on the extent of surface damage to the dishes. Most of the MPs (41.7-81.5%) derived from scratching could be retrieved along with sperm cells, with an estimated exposure dose of 100-22,000 particles/mL. We offered reliable evidence of direct human sperm exposure to MPs and advocate limiting plasticware use to reduce early life health risks for ART-conceived babies.

The biggest bottleneck for nanozymes-initiated chemodynamic therapy (CDT) of cancer is that nanozymes cannot continuously yield hydroxyl radicals towards lasting CDT, given their diffusion and clearance from tumor tissues as well as lower tumor accumulation. Herein, based on a composition-transformable bovine serum albumin (BSA) modified Cu/CuFe2O4 (CCFOB) nanozyme, we present a novel avenue to achieve lasting CDT. This CCFOB nanozyme with peroxidase (POD)-like activity and glutathione depletion ability not only amplifies oxidative stress for effective CDT, but exhibits magnetic targeting and imaging-guided simultaneous photothermal therapy (PTT)/magnetic hyperthermia therapy (MHT)/chemotherapy. Contrasting with traditional cognition, we clarify Cu/CuFe2O4 is actually composed of CuFe2O4 nanocrystal clusters and Cu nanospheres. Attractively, for the first time, it is demonstrated that in microenvironment of residual tumors, CCFOB nanozyme could be progressively transformed into BSA modified Cu2O/Cu/CuFe2O4, which renders CCFOB to be a Cu+ reservoir to continuingly produce high-reactivity Cu+. Such continuing production of Cu+ grants CCFOB nanozyme increasingly enhanced POD-like activity for lasting CDT despite its diffusion and clearance from tumor tissues. Thus, a programmed synergistic therapy strategy starting with high-intensity PTT/MHT/chemotherapy/ CDT to eradicate larger tumors, followed by lasting CDT to eliminate residual tumors and prevent tumor recurrence, has been put forward to eventually realize the concept of "one injection, long-lasting and complete therapy of cancer". This strategy may provide a new insight for the design of other high-activity nanozymes.

Cervical human papillomavirus (HPV) infection is believed to increase the risks of pregnancy failure and abortion, however, whether the uterine cavity HPV infection reduces pregnancy rate or increases miscarriage rate remains unclarified in infertile women undergoing assisted reproductive technology (ART) treatment. Therefore, we aimed to assess ART outcomes in the presence of intrauterine HPV. This was a hospital-based multicenter (five reproductive medicine centers) matched cohort study. This study involved 4153 infertile women undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection treatment in five reproductive medicine centers between October 2018 and 2020. The spent embryo transfer media sample with endometrium tissue were collected and performed with flow-through hybridization and gene chips to detect HPV DNA. According to basic characteristics, HPV-positive and negative patients were matched in a ratio of 1:4 by age, body mass index transfer timing, transfer type, and number of embryos transferred. The primary outcome was pregnancy and clinical miscarriage rates in the transfer cycle underwent HPV detection. 92 HPV-positive and 368 HPV-negative patients were screened and analyzed statistically. Univariate analysis showed uterine cavity HPV infection resulted in lower rates of ongoing pregnancy (31.5% vs. 44.6%; p=0.023), implantation (32.3% vs. 43.1%; p=0.026), biochemical pregnancy (47.8% vs. 62.5%; p=0.010), and clinical pregnancy (40.2% vs. 54.3%; p=0.015) compared with HPV negative group. The infertile female with positive HPV also had a slightly higher frequency of biochemical miscarriage (15.9% vs. 13.0%; p=0.610) and clinical miscarriage (24.3% vs. 15.5%; p=0.188). These findings suggest that HPV infection in the uterine cavity is a high risk for ART failure. HPV screening is recommended before ART treatment, which may be benefit to improving pregnancy outcome.

An effective tool to assess embryo quality in the assisted reproduction clinical practice will enhance successful implantation rates and mitigate high risks of multiple pregnancies. Potential biomarkers secreted into culture medium (CM) during embryo development enable rapid and noninvasive methods of assessing embryo quality. However, small volumes, low biomolecule concentrations, and impurity interference collectively preclude the identification of quality-related biomarkers in single blastocyst CM. Here, we developed a noninvasive trace multiomics approach to screen for potential markers in individual human blastocyst CM. We collected 84 CM samples and divided them into high-quality (HQ) and low-quality (LQ) groups. We evaluated the differentially expressed proteins (DEPs) and metabolites (DEMs) in HQ and LQ CM. A total of 504 proteins and 189 metabolites were detected in individual blastocyst CM. Moreover, 9 DEPs and 32 DEMs were identified in different quality embryo CM. We also categorized HQ embryos into positive implantation (PI) and negative implantation (NI) groups based on ultrasound findings on day 28. We identified 41 DEPs and 4 DEMs associated with clinical implantation outcomes in morphologically HQ embryos using a multiomics analysis approach. This study provides a noninvasive multiomics analysis technique and identifies potential biomarkers for clinical embryo developmental quality assessment.

Ionizing radiation (IR)-induced intestinal injury remains a major limiting factor in abdominal radiation therapy, and its pathogenesis remains unclear. In this study, mouse models of IR-induced intestinal injury were established, and the effect of IR on nuclear factor erythroid 2-related factor 2 (Nrf2) was determined. More severe IR-induced intestinal damage was observed in Nrf2 knockout (KO) mice than in wild-type mice. Then, the negative regulation of cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) signaling by Nrf2 was examined both in vivo and in vitro after IR. This was accompanied by alterations in the intestinal neutrophil and macrophage populations in mice. Subsequently, the effect of the cGAS/STING pathway on the intestinal toxicity of IR was also investigated. Moreover, the downregulation of cGAS/STING by Nrf2 via its target gene, Pirin, was confirmed using transfection assays. A rescue experiment with Pirin was also conducted using adeno-associated virus in Nrf2 KO mice. Finally, the protective effect of calcitriol against IR-induced intestinal injury, along with increased Nrf2 and Pirin levels and decreased cGAS, pSTING, and interferon-beta levels, were observed. Taken together, our results suggest that Nrf2 alleviates IR-induced intestinal injury through Pirin-mediated inhibition of the innate immunity-related cGAS/STING pathway.

Background The enriched proteins within in vitro fertilisation (IVF)-generated human embryonic microenvironment could reverse progestin resistance in endometrial cancer (EC). Methods The expression of thymic stromal lymphopoietin (TSLP) in EC was evaluated by immunoblot and IHC analysis. Transcriptome sequencing screened out the downstream pathway regulated by TSLP. The role of TSLP, androgen receptor (AR) and KANK1 in regulating the sensitivity of EC to progestin was verified through a series of in vitro and in vivo experiments. Results TSLP facilitates the formation of a BMP4/BMP7 heterodimer, resulting in activation of Smad5, augmenting AR signalling. AR in turn sensitises EC cells to progestin via KANK1. Downregulation of TSLP, loss of AR and KANK1 in EC patients are associated with tumour malignant progress. Moreover, exogenous TSLP could rescue the anti-tumour effect of progestin on mouse in vivo xenograft tumour. Conclusions Our findings suggest that TSLP enhances the sensitivity of EC to progestin through the BMP4/Smad5/AR/KANK1 axis, and provide a link between embryo development and cancer progress, paving the way for the establishment of novel strategy overcoming progestin resistance using embryo original factors.

AbstractBackgroundHigh‐risk human papillomavirus (hrHPV) infection is a key factor that alters cervicovaginal microbiota patterns and causes cervical intraepithelial neoplasias (CINs) or even cervical cancer. Although local excisional treatment can clear hrHPV infection and restore the cervicovaginal microbiota, it is unclear which cervicovaginal microbiota represents recovery. Our objective was to describe the cervicovaginal microbiota before and after treatments and to assess the association between the microbiota and HPV persistence.ResultsA cohort of 91 participants was classified into four groups (healthy control women and HPV16‐infected women with CIN I, CIN II/III, and squamous cell carcinoma [SCC]). Endocervical swabs were collected 3 months prior to treatment and at 3 months post‐treatment for bacterial 16S rRNA gene pyrosequencing and for HPV DNA testing. There was an increase in the number of Lactobacillus bacterial species present after the clinical treatments, and the community state type (CST) profiles were shifted from dysbiotic CSTs II and IV to Lactobacillus‐dominated CSTs I and III. Specifically, the composition of Geobacter and Prevotella before treatment and Lactobacillus secaliphilus after treatment might have been related to CIN I, the composition of Burkholderia before treatment and Lactobacillus iners after treatment might have been related to CIN II/III, and the composition of Atopobium and Aerococcus before treatment and Bacilli after treatment might have been related to SCC. Further functional predictions revealed that the composition differences were linked to infectious disease‐ and cancer‐related genes.ConclusionOur study provides an illustration of the changes in CSTs and the cervicovaginal microbiota before and after HPV16 clearance in each disease state.

With a younger tendency in morbidity age, endometrial cancer (EC) incidence has grown year after year. Worse, even more commonly occurring is endometrial hyperplasia (EH), which is a precancerous endometrial proliferation. For young women with early EC and EH who want to preserve fertility, progestin therapy has been utilized as a routine fertility-preserving treatment approach. Nevertheless, progestin medication failure in some patients is mostly due to progestin resistance and side effects. In order to further analyze the potential mechanisms of progestin resistance in EH and EC, to provide theoretical support for effective therapeutic strategies, and to lay the groundwork for searching novel treatment approaches, this article reviews the current therapeutic effects of progestin in EH and EC, as well as the mechanisms and molecular biomarkers of progestin resistance, and systematically expounds on the potential therapeutic methods to overcome progestin resistance.

Progestin resistance is the main obstacle for the conservative therapy to maintain fertility in women with endometrial cancer. Brusatol was identified as an inhibitor of the NRF2 pathway; however, its impact on progestin resistance and the underlying mechanism remains unclear. Here, we found that brusatol sensitized endometrial cancer to progestin by suppressing NRF2-TET1-AKR1C1-mediated progestin metabolism. Brusatol transcriptionally suppressed AKR1C1 via modifying the hydroxymethylation status in its promoter region through TET1 inhibition. Suppression of AKR1C1 by brusatol resulted in decreased progesterone catabolism and maintained potent progesterone to inhibit endometrial cancer growth. This inhibition pattern has also been found in the established xenograft mouse and organoid models. Aberrant overexpression of AKR1C1 was found in paired endometrial hyperplasia and cancer samples from the same individuals with progestin resistance, whereas attenuated or loss of AKR1C1 was observed in post-treatment samples with well progestin response as compared with paired pre-treatment tissues. Our findings suggest that AKR1C1 expression pattern may serve as an important biomarker of progestin resistance in endometrial cancer. For precancerous/endometrial cancer patients with fertility maintain desire, progestin resistance is the main obstacle of conservative therapy. The authors found that brusatol, as a natural compound, suppresses progestin metabolism through regulating the NRF2-TET1-AKR1C1 pathway to sensitize precancerous/endometrial cancers to progestin and relieve progestin resistance. This study indicates that progestin combined with brusatol may enhance the treatment effects and that AKR1C1 expression patterns may serve as an important biomarker of progestin resistance in endometrial cancer.

Background Although evidence has revealed that miR-200a-3p is involved in the malignant progression of various tumors, the regulatory mechanism of miR-200a-3p in the development of cervical cancer (CC) cells with different HPV statuses remains unknown. The present study was to investigate the differential effects of either miR-200a-3p or YAP on tumorous cells’ fate in vitro in HPV-negative and HPV-positive cervical cancer cell models, and to explore if the changes in proliferation, migration, and invasion of the CC cells with different HPV statuses could be attributed to the differential interactions between miR-200a-3p and YAP. Methods The colony formation assays, EDU assays and Transwell assays were performed for CC cell proliferation, migration and invasion capacities analysis. The prediction of downstream targets of miR-200a-3p was performed by bioinformatical databases. The dual-luciferase reporter assays were used to validate the binding sites of miR-200a-3p and YAP. The qRT-PCR assays were performed to quantify the mRNA expression of miR-200a-3p and YAP, and the protein levels of YAP were examined by Western blot analysis. Results The results demonstrated that miR-200a-3p overexpression suppressed proliferation, migration, and invasion of the HPV-negative C33A cells but promoted the growth and metastasis of HPV-positive CC cells, while YAP promoted the cell growth and metastasis not only in HPV-negative but also in the HPV-positive CC cells. The suppressive role of miR-200a-3p in C33A cells appeared to be mediated partially by direct interaction with YAP, and YAP might participate in miR-200a-3p-mediated cellular changes in CC cells differing from not only the presence or absence of HPV but even also the subtypes of HPV of CC cells. Meanwhile, we preliminarily revealed that the expression level of miR-200a-3p was significantly decreased in HPV-negative, but not in HPV16-positive cervical neoplasm mucus samples. Conclusion miR-200a-3p-mediated functional changes of YAP exhibited regulatory effects on cells’ fate differentially in HPV-negative and HPV-positive cervical cancer cells.

Common uterine diseases include endometriosis, uterine fibroids, endometrial polyps, endometrial hyperplasia, endometrial cancer, and endometrial dysfunction causing infertility. Patients with uterine diseases often suffer from abdominal pain, menorrhagia, infertility and other symptoms, which seriously impair their health and disturb their lives. Androgens play important roles in the normal physiological functions of the uterus and pathological progress of uterine diseases. Androgens in women are synthesized in the ovaries and adrenal glands. The action of androgens in the uterus is mainly mediated by its ligand androgen receptor (AR) that regulates transcription of the target genes. However, much less is known about the signaling pathways through which androgen functions in uterine diseases, and contradictory findings have been reported. This review summarizes and discusses the progress of research on androgens and the involvement of AR in uterine diseases. Future studies should focus on developing new therapeutic strategies that precisely target specific AR and their related signaling pathways in uterine diseases.

Progestin administration serves as the optimal conservative treatment method for women with endometrial cancer or precancer lesions who want to preserve fertility. However, there are still at least 30% of patients in which progestin resistance occurs. LASS2 (Ceramide Synthase 2) has been reported to be involved in chemotherapy resistance, whether it also plays a role in progestin resistance is not clear. Here, we explored the detailed mechanism by which Nrf2/LASS2 contributes to progestin resistance and disease progression. Methods: IHC assays were performed to estimate the expression pattern of Nrf2 and LASS2. Moreover, it bears three antioxidant response elements (ARE) in the promoter region of LASS2 gene, therefore, Luciferase assays were performed to determine if Nrf2 regulates LASS2 by binding with these ARE sequence. Western Blot assays were used to determine the expression of Nrf2 and LASS2 protein among various endometrial cell lines. Relative mRNA expression levels were detected by RT-PCR. Cellular growth was monitored with CCK-8 tests. Apoptosis was determined with Annexin V-PI staining and flow cytometry analysis. siRNA knockdown was performed to investigate the effects of Nrf2 on cell proliferation. Result: Nrf2/LASS2 is highly expressed in endometrial cancer tissue, as compared to expression levels in normal endometrial tissue. Proliferation assays demonstrated that overexpression of Nrf2/LASS2 resulted in progestin resistance. Conversely, knockdown of LASS2 increased apoptosis and decreased cell viability. In addition, metformin overcame progestin resistance by down-regulating Nrf2/LASS2 expression. Conclusion: Our findings provide new insight into the mechanism of progestin resistance in type I endometrial cancer. Nrf2/LASS2 may not only be a possible marker for predicting the prognosis of endometrial cancer but also serve as a potential therapeutic target.

Background : Chemoresistance reduces the 5-year survival rate of endometrial cancer patient, which is the current major obstacle for cancer therapy. Increasing evidence state that Nrf2 contributes to chemoresistance in several kinds of cancer. However, its role in endometrial cancer cells remains unclarified. Methods : Immunohistochemistry staining was used to detect the expression of Nrf2 in normal patient and endometrial cancer patient. Stable transfection Ishikawa cell line with high level of Nrf2 was established to evaluate its role in chemoresistance. Dot blot assays were used to assess global hydroxymethylation level after stigmasterol treatment. Cellular growth profile was detected by CCK8 assay. Western blot was used to evaluate the changes of the target molecules after various treatments. Results : Nrf2 is overexpressed in endometrial cancer tissues compared with the normal endometrium. Overexpression of Nrf2 resulted in decrease sensitivity to cisplatin. In addition, stigmasterol has been identified as a novel Nrf2 inhibitor. It enhanced the sensitivity of endometrial cancer cells to cisplatin, and the underlying mechanism is that stigmasterol declines the Nrf2 protein level. Conclusions : Our findings identified stigmasterol as a new potential inhibitor of Nrf2 and highlight a critical role of stigmasterol in overcoming chemoresistance in endometrial cancer therapy.

Gestational diabetemellitus (GDM) is a condition whereby a mother's glucose tolerance is impaired with onset or first recognition during pregnancy which is not either type 1 or type 2 diabetes mellitus. Oxidative stress plays an essential role in diabetes, however, whether it also includes in GDM has not been fully clarified. Therefore, we investigated the changes of oxidative stress biomarkers and their relationship with pregnancy outcomes in patients with GDM. The serum and placenta were collected for absorbance-based assay and immunohistochemistry assay (IHC). The patients' clinical information was collected and the pregnancy outcome was tracked. It was found that elder age is a risk factor to result in GDM. Moreover, GDM patients showed poor clinical factors or outcomes including higher prepregnancy weight and BMI value, premature delivery, higher rates of cesarean delivery, macrosomia, premature rupture of fetal membranes (PROM). Increasing serum MDA level and decline GSH and SOD levels were observed in GDM patients. Meanwhile, HO-1, Nrf2 and NQO1 overexpressed in GDM placental tissues. In the GDM group, MDA level was negatively associated with prepregnancy weight, while, SOD level was positively correlated with neonatal birth weight. We found an intensive relationship between SOD content and preterm birth in the GDM group. There is no significant difference between the level of MDA/GSH and neonatal birth weight as well as preterm birth. MDA, GSH and SOD levels were not associated with an increased risk of cesarean delivery or PROM. This study indicates aberrant expression of oxidative stress related proteins affects the pregnancy outcome of GDM patients.

目的:研究GDM孕妇与正常孕妇血清MDA、SOD及GSH水平变化,探索它们与GDM之间的相互关系,追踪各组妊娠结局研究其临床意义.方法:选取175例孕妇为研究对象,分为GDM组(93例)和对照组(82例).采用微量法测定血清丙二醛(MDA)、谷胱甘肽(GSH)及超氧化物歧化酶(SOD)水平,并对妊娠结局进行相关性分析.结果:(1) GDM组年龄、孕前体重、BMI值均高于对照组,GSH和SOD水平均低于对照组,MDA水平高于对照组,差异有统计学意义(P＜0.05);(2) GDM组MDA水平与孕前体重呈负相关(r=-0.3547,P＜0.05),SOD水平与新生儿出生体重呈正相关(r=0.3292,P＜0.05),SOD值与早产之间有密切联系(足月产12.68±0.85 vs.早产8.08±1.18,P＜0.05),GSH、SOD水平与孕前体重之间,MDA、GSH水平与新生儿出生体重之间,MDA、GSH水平与早产之间均无明显相关性(P＞0.05),MDA、GSH和SOD水平与剖宫产及胎膜早破均无明显相关性(P＞0.05).结论:GDM存在明显的氧化应激反应,GSH、MDA与SOD可以作为评估GDM氧化应激的有效标志物,其与不良妊娠结局有关.

Chemoresistance is the major obstacle to cure endometrial cancer, whereas metformin has demonstrated sensitization to chemotherapy in endometrial cancer. A novel finding states that isocitrate dehydrogenase 1 (IDH1) involves in cancer chemoresistance. Recent studies have revealed that epigenetic modifications facilitate chemoresistance. However, whether IDH1 play a role in metformin-induced endometrial cancer chemosensitivity through epigenetic modification is incompletely understood. Immunohistochemistry and Elisa assays were used to evaluate the expression pattern of IDH1 in endometrial tissue and serum, respectively. Western blot was performed to determine changes in expression of key molecules in the IDH1-ɑ-KG-TET1-Nrf2 signaling pathway after various treatments. Dot blot assays were used to assess global hydroxymethylation levels after metformin administration or plasmid transfection. Antioxidant response element (ARE) activity in the IDH1 promoter region was monitored by luciferase assay. Cancer cell sensitivity to chemotherapy was detected by SRB assay. We found that activation of the IDH1 signaling pathway in endometrial cancer tissue resulting from aberrant expression of IDH1 and its downstream mediators conferred chemoresistance. We found that this effect was abated by metformin treatment. Dot blot and HMeDIP assays revealed that metformin blocked IDH1-ɑ-KG-TET1-mediated enhancement of Nrf2 hydroxymethylation levels, eliminating chemoresistance. Moreover, we observed that chemoresistance was enhanced via a regulatory loop in which Nrf2 activated IDH1-ɑ-KG-TET1-Nrf2 signaling via binding to the ARE sites in the IDH1 promoter region. Our findings highlight a critical role of IDH1-ɑ-KG-TET1-Nrf2 signaling in chemoresistance and suggest that rational combination therapy with metformin and chemotherapeutics has the potential to suppress chemoresistance.

Problem To examine whether the level of plasma D‐dimer can guide anticoagulant treatment in recurrent pregnancy loss ( RPL ) associated with antiphospholipid syndrome ( APS ). Methods A total of 1096 RPL women with APS between 2012 and 2015 in a single‐center hospital were randomly divided into two groups (group A, 75 mg of low‐dose aspirin [ LDA ] daily; group B, 75 mg of LDA plus 4100 U of low molecular weight heparin [ LMWH ] subcutaneously daily); 1015 of the total successfully completed the trial. Plasma D‐dimer level and live birth rates were estimated. Results For APS women with an elevated D‐dimer level at baseline, higher live birth rates were reached in LDA plus LMWH group compared to LDA alone group (92.71% vs 61.68%, P < .0001); however, no significant differences were found between the two groups of women with a normal D‐dimer level (87.08% vs 83.76%, P = .48). Women with a normal D‐dimer level at all blood draw points had the highest live birth rates (92.88%), as compared with those with persistently abnormal D‐dimer at all blood draw points or increased D‐dimer level after treatment ( P < .001). Conclusion The combination therapy with LDA and LMWH is not essential for all APS women, but has proven to be beneficial for women with an elevated D‐dimer level.

Progestin resistance is a main obstacle for endometrial precancer/cancer conservative therapy. Therefore, biomarkers to predict progestin resistance and studies to gain a more detailed understanding of the mechanism are needed. The antioxidant Nrf2-AKR1C1 signal pathway exerts chemopreventive activity. However whether it plays a role in progestin resistance has not been explored. In this study, elevated levels of AKR1C1 and Nrf2 were found in progestin-resistant endometrial epithelia, but not in responsive endometrial glands. Exogenous overexpression of Nrf2/AKR1C1 resulted in progestin resistance. Inversely, silencing of Nrf2 or AKR1C1 rendered endometrial cancer cells more susceptible to progestin treatment. Moreover, medroxyprogesterone acetate withdrawal resulted in suppression of Nrf2/AKR1C1 expression accompanied by a reduction of cellular proliferative activity. In addition, brusatol and metformin overcame progestin resistance by down-regulating Nrf2/AKR1C1 expression. Our findings suggest that overexpression of Nrf2 and AKR1C1 in endometrial precancer/cancer may be part of the molecular mechanisms underlying progestin resistance. If validated in a larger cohort, overexpression of Nrf2 and AKR1C1 may prove to be useful biomarkers to predict progestin resistance. Targeting the Nrf2/AKR1C1 pathway may represent a new therapeutic strategy for treatment of endometrial hyperplasia/cancer.

Recent studies have suggested that elevated gonadotropins contribute to ovarian epithelial tumor (OET) cell proliferation. However, the cellular effects of luteinizing hormone, a member of gonadotropins, on OET proliferation are controversial. Our previous work showed that luteinizing hormone has no effect on cell proliferation, but the molecular mechanism of such finding remains to be clarified. Considering that the cell growth in various types of tumors has been associated with regulations of prohibitin and matrix metalloproteinases, we aim to investigate a possible regulatory role of luteinizing hormone on prohibitin and matrix metalloproteinases to determine the roles of these molecules in OET proliferation. We found that LH stimulation resulted in a dose-dependent expression of prohibitin and MMPs and time-dependent phosphorylations of ERK and AKT. Blocking MAPK or PI3K/AKT signaling could attenuate LH-induced prohibitin and MMPs expression. Additionally, the depletion of prohibitin reduced the level of MMPs expression, and increased prohibitin expression abolished the positive effect of LH-induced MMP-9 on cellular growth. Therefore, we conclude that LH is able to up-regulate both prohibitin and MMP-9 in OET cells without the cellular growth effect due to opposing biologic functions for cell proliferation between these two molecules. The opposing cellular growth function between prohibitin and MMP-9 is a novel finding. Regulation of either molecule may be useful for future targeted therapy for ovarian epithelial cancers.