Follicular fluid-derived exosomal LncRNA LIPE-AS1 modulates steroid metabolism and survival of granulosa cells leading to oocyte maturation arrest in polycystic ovary syndrome.

OBJECTIVE: Women who are of reproductive age can suffer from polycystic ovary syndrome (PCOS), an endocrine disorder. Anovulatory infertility is mostly caused by aberrant follicular development, which is seen in PCOS patients. Due to the dysfunction of reproductive and endocrine function in PCOS patients, assisted reproduction treatment is one of the main means to obtain clinical pregnancy for PCOS patients. Long non-coding RNA (lncRNA) as a group of functional RNA molecules have been found to participate in the regulation of oocyte function, hormone metabolism, and proliferation and apoptosis of granulosa cells. In this study, we investigated the role of lncRNAs in follicular fluid-derived exosomes and the underlying mechanism of lncRNA LIPE-AS1. METHODS: We used RNA sequencing to analyze the lncRNA profiles of follicular fluid-derived exosomes in PCOS patients and controls. RT-qPCR was performed to detect the expression levels of these lncRNAs in control (n = 30) and PCOS (n = 30) FF exosome samples. Furthermore, we validated the performance of lncRNA LIPE-AS1 in oocyte maturation by in vitro maturation (IVM) experiments in mouse and steroid metabolism in granulosa cells. RESULTS: We found 501 lncRNAs were exclusively expressed in the control group and another 273 lncRNAs were found to be specifically expressed in the PCOS group. LncRNA LIPE-AS1, highly expressed in PCOS exosomes, was related to a poor oocyte maturation and embryo development in PCOS patients. Reduced number of MII oocytes were observed in the LIPE-AS1 group by in vitro maturation (IVM) experiments in mouse. LIPE-AS1 was also shown to modulate steroid metabolism and granulosa cell proliferation and apoptosis by LIPE-AS1/miR-4306/LHCGR axis. CONCLUSION: These findings suggested that the increased expression of LIPE-AS1, facilitated by follicular fluid exosomes, had a significant impact on both oocyte maturation and embryo development. We demonstrated the ceRNA mechanism involving LIPE-AS1, miR-4306, and LHCGR as a regulator of hormone production and metabolism. These findings indicate that LIPE-AS1 is essential in PCOS oocyte maturation and revealed a ceRNA network of LIPE-AS1 and provided new information on abnormal steroid metabolism and oocyte development in PCOS.

Exosomal circ_0008285 in follicle fluid regulates the lipid metabolism through the miR-4644/ LDLR axis in polycystic ovary syndrome.

PURPOSE: Exosomal circRNA, as an essential mediator of the follicular microenvironment, has been implicated in the etiological and pathobiological studies of polycystic ovarian syndrome (PCOS). This study aimed to determine abnormal circular RNA (circRNA) expression profiles in follicle fluid (FF) exosomes in patients with PCOS and identify the role of circ_0008285/microRNA (miR)-4644/low-density lipoprotein receptor (LDLR) axis in PCOS. METHODS: Sixty-seven women undergoing IVF/ICSI, 31 PCOS patients and 36 non-PCOS patients were included in the cohort study. The circRNA expression profiles of FF exosomes in PCOS (n = 3) and control group (n = 3) were compared by RNA sequencing. In an additional cohort (PCOS:28 vs Control:33), the mRNA expression levels of four circRNAs from FF exosomes were further verified by qRT-PCR. Bioinformatic analysis and dual luciferase reporter gene assay verified the relationship between circ_0008285 and miR-4644 and between miR-4644 and LDLR. KGN cells were infected with sh-circ0008285 and transfected with miR-4644 mimic to verify their roles in lipid metabolism. RESULTS: Four circRNAs showed significantly different expressions. Circ_0044234 was overexpressed in PCOS patients, while circ_0006877, circ_0013167 and circ0008285 were decreased in PCOS. Among four differentially expressed circRNAs, circ0008285 was enriched in lipoprotein particle receptor activity and cholesterol metabolism pathway by GO and KEGG pathway analyses. Luciferase assay confirmed the competing endogenous RNA (ceRNA) network circ_0008285/miR-4644 /LDLR. The intercellular experiments on circ_0008285 and its reduction in KGN cells showed that the consumption of circ_0008285 in exosomes could increase the expression of miR-4644 in recipient cells and inhibit the expression of LDLR, as well as increase free fatty acid secretion. CONCLUSION: Circ_0008285 can combine with miR-4644 to promote the expression of LDLR and affect the cholesterol metabolism of ovarian granulosa cells in PCOS. Our findings revealed the ceRNA network of circ_0008285 and provided a new path to investigate lipid metabolism abnormalities in PCOS.

Design of Nanostructured Surfaces for Efficient Condensation by Controlling Condensation Modes.

To meet the different needs of various industrial fields, it is of great application value to find a feasible method for controlling the condensation mode on the surface. Inspired by biological surfaces, tuning the surface structure and wettability is considered as a potential way to control the surface condensation behavior. Herein, the coupling effect of the geometric parameters and wettability distribution of the surface on the condensation process has been investigated systematically at the nanoscale. The results illustrate that the condensation mode is primarily determined by the nanopillar wettability when the nanopillars are densely distributed, while the substrate wettability dominates the condensation mode when the nanopillars are sparsely distributed. Besides, the effective contact area fraction is proposed, which more accurately reflects the influence of geometric parameters on the condensation rate of the nanopillar surface at the nanoscale. The condensation rate of the nanopillar surface increases with the increase of the effective contact area fraction. Furthermore, three surface design methods are summarized, which can control the condensation mode of water vapor on the surface into the dropwise condensation mode that generates Cassie-Baxter droplets, and this condensation process is very attractive for many practical applications.

Uropathogenic Escherichia coli Infection Compromises the Blood-Testis Barrier by Disturbing mTORC1-mTORC2 Balance.

The structural and functional destruction of the blood-testis barrier (BTB) following uropathogenic E. coli (UPEC) infection may be a critical component of the pathologic progress of orchitis. Recent findings indicate that the mammalian target of the rapamycin (mTOR)-signaling pathway is implicated in the regulation of BTB assembly and restructuring. To explore the mechanisms underlying BTB damage induced by UPEC infection, we analyzed BTB integrity and the involvement of the mTOR-signaling pathway using in vivo and in vitro UPEC-infection models. We initially confirmed that soluble virulent factors secreted from UPEC trigger a stress response in Sertoli cells and disturb adjacent cell junctions via down-regulation of junctional proteins, including occludin, zonula occludens-1 (ZO-1), F-actin, connexin-43 (CX-43), ß-catenin, and N-cadherin. The BTB was ultimately disrupted in UPEC-infected rat testes, and blood samples from UPEC-induced orchitis in these animals were positive for anti-sperm antibodies. Furthermore, we herein also demonstrated that mTOR complex 1 (mTORC1) over-activation and mTORC2 suppression contributed to the disturbance in the balance between BTB "opening" and "closing." More importantly, rapamycin (a specific mTORC1 inhibitor) significantly restored the expression of cell-junction proteins and exerted a protective effect on the BTB during UPEC infection. We further confirmed that short-term treatment with rapamycin did not aggravate spermatogenic degeneration in infected rats. Collectively, this study showed an association between abnormal activation of the mTOR-signaling pathway and BTB impairment during UPEC-induced orchitis, which may provide new insights into a potential treatment strategy for testicular infection.

Correction: AMF/PGI-mediated tumorigenesis through MAPK-ERK signaling in endometrial carcinoma.

[This corrects the article DOI: 10.18632/oncotarget.4708.].

Long Noncoding RNA HUPCOS Promotes Follicular Fluid Androgen Excess in PCOS Patients via Aromatase Inhibition.

CONTEXT: Androgen excess is a key feature of polycystic ovary syndrome (PCOS), but the underlying molecular mechanism remains unclear. OBJECTIVE: To determine the role and mechanism of novel long noncoding RNA (lncRNA) highly up-regulated in PCOS (HUPCOS) in the androgen excess of PCOS patients. DESIGN: The lncRNA expression profile in granulosa cells derived from PCOS and non-PCOS women were analyzed by using microarray assay. Human granulosa cell line KGN was used for mechanism investigation. SETTING: This was a university-based study. PATIENTS: Thirty-eight PCOS and 38 control patients were recruited: 8 PCOS and 8 control samples used for microarray discovery, the remaining 30 PCOS cases and 30 controls for quantitative RT-PCR validation. MAIN OUTCOME MEASURES: The aberrant expression lncRNA profile of PCOS patients was measured using microarray. The relationship of HUPCOS and follicular fluid testosterone was measured. Aromatase expression were analyzed after HUPCOS downregulation. HUPCOS interaction protein was confirmed by RNA pull-down. RESULTS: The significantly elevated lncRNA in PCOS granulosa cells was named HUPCOS, which was positively correlated with follicular fluid testosterone of PCOS patients. HUPCOS downregulation increased aromatase expression and promoted conversion of androgen to estrogen. RNA-binding protein with multiple splicing (RBPMS) was the most likely protein that combined with HUPCOS. CONCLUSIONS: Our findings suggested that HUPCOS mediated androgen excess in follicular fluid of PCOS patients by suppressing aromatase expression via interaction with RBPMS.

Effect of substrate wettability and flexibility on the initial stage of water vapor condensation.

Understanding the mechanisms of controlling vapor condensation on surfaces is of significant importance in many fields. Despite many efforts made in the investigation of vapor condensation, few studies concern the condensation on flexible substrates, especially in microscale. In this paper, the condensation of high temperature water vapor on substrate with various flexibilities and wettabilities is investigated using molecular dynamics simulation. The results indicate that when substrates with the same flexibility vary from hydrophobic to hydrophilic, the condensation rate increases and the condensation mode changes from no-condensation to dropwise condensation, incomplete filmwise condensation and filmwise condensation, and meanwhile, the heat exchange between the water vapor and the substrate becomes more efficient; when substrates with the same wettability vary from rigid to flexible, the nucleation density, the condensation rate and the heat exchange efficiency increase significantly. In particular, the condensation modes on rigid and flexible substrates with the same wettability are generally the same except for the substrates with εwater-Cu = 0.4 kcal mol-1; and the critical values of substrate spring constant for the condensation mode transition are about 80-100 kcal mol-1 Å-2 when εwater-Cu = 0.4 kcal mol-1. Therefore, changing the flexibility of the substrate is proposed as a new way to control the condensation mode at the initial stage of water vapor condensation to meet design requirements.

Synergistic removal of tylosin/sulfamethoxazole and copper by nano-hydroxyapatite modified biochar.

Antibiotics and heavy metals are frequently detected simultaneously in aquatic environment. In this study, we investigated the removal performance of biochar modified with nano-hydroxyapatite (nHAP, nHAP@biochar) on tylosin (TYL) /sulfamethoxazole (SMX) and Cu(II) simultaneously. Six nHAP@biochars were prepared with different feedstock and nHAP and biomass ratios. The influences of feedstock and nHAP and biomass ratios, interaction of TYL/SMX and Cu(II) and thermodynamic study were investigated. The adsorption quantities on nHAP@biochars prepared by wood-processing residues were higher than by Chinese medicine residues. The adsorption amounts of TYL decreased with the addition of Cu(II), while the adsorption quantities of SMX increased. The adsorptions of Cu(II) were promoted by TYL and changed slightly with the increasing of SMX. Specific surface area and pore size were two of the main factors influencing the adsorption capacities of nHAP@biochars. According to density functional theory, nHAP@biochar-TYL-Cu and nHAP@biochar-Cu-SMX were more existed in the systems.

Downregulation of miR-322 promotes apoptosis of GC-2 cell by targeting Ddx3x.

BACKGROUND: Aberrant DNA damage of germ cells, which impairs spermatogenesis and lowers fertility, is an important factor contributing to male infertility. MicroRNAs (miRNAs) play a significant role in the expression and regulation of multiple genes during spermatogenesis. Our previous study found much lower miR-424 (murine homologue miR-322) levels in the seminal plasma of infertile patients with high DFI(DNA Fragmentation Index)than in the fertile group. However, the mechanism by which miR-322 regulates germ cells during spermatogenesis remains unknown. METHODS: In this study, we successfully established a GC-2 cell model of miR-322 downregulation resulting in impaired spermatogenesis. And the cell viability were measured using Cell Counting Kit-8 (CCK-8; Dojindo, Japan) and MTT (Sigma Aldrich, USA). Immunofluorescence assay was used to detect cell damage and the expression of apoptosis-related proteins were measured using real-time quantitative PCR and Western blot analysis. Target genes were predicted and verified by online database retrieval and Dual-luciferase reporter gene assay. RESULTS: We observed evident decreases in the cell viability of GC-2 cells along with remarkable increases in apoptosis after miR-322 inhibition. While the expression of apoptosis-related genes, including Bax and caspases 3, 9, and 8 greatly increased in GC-2 cells after miR-322 downregulation, that of the anti-apoptotic Bcl-2 gene decreased. Ddx3x was found to be the direct target of miR-322. MiR-424 was then detected in the seminal plasma of infertile patients with high DFI(DNA Fragmentation Index); this miRNA was down-regulated but Ddx3x was upregulated in the infertile group. CONCLUSION: MiR-322 plays a key role in promoting GC-2 cell apoptosis by directly regulating Ddx3x expression. MiR-424 downregulation in infertile men may induce spermatogenic cell apoptosis and sperm DNA damage by directly acting on the target gene locus Ddx3x, resulting in male infertility.

17ß-Estradiol promotes endometrial cancer proliferation and invasion through IL-6 pathway.

Accumulating evidence revealed that the leading risk factor of endometrial cancer is exposure to endogenous and exogenous estrogens, while the exact mechanism underlying estrogen contribution to endometrial cancer progression has not been elucidated clearly. Interleukin (IL)-6 has been verified to be critical for tumor progression in several human cancers. In this study, we provided evidence that 17ß-estradiol (E2) could significantly promote endometrial cancer cells viability, migration and invasion through activation of IL-6 pathway, which involved in its downstream pathway and target genes (p-Stat3, Bcl-2, Mcl-1, cyclin D1 and MMP2). Meanwhile, utilization of IL-6-neutralizing antibody could partially attenuate the increased cancer growth and invasion abilities in Ishikawa and RL95-2 endometrial cancer cell lines and an orthotopic endometrial cancer model. We established a causative link between estrogen and IL-6 signaling activation in the development of endometrial cancer. The molecular mechanism defined in this study provided the evidence that E2 promotes endometrial carcinoma progression via activating the IL-6 pathway, indicating that interruption of IL-6 might be an essential therapeutic strategy in estrogen-dependent endometrial cancer.

Characterization of circular RNA expression profiles in cumulus cells from patients with polycystic ovary syndrome.

OBJECTIVE: To determine aberrant circular RNA (circRNA) expression profiles in cumulus cells from polycystic ovarian syndrome (PCOS) patients and identify their potential biological functions. DESIGN: Circular RNAs microarray analysis of human tissue. SETTING: University hospital. PATIENT(S): A total of 40 women, including 20 PCOS patients and 20 non-PCOS patients. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): A circRNA microarray containing probes that interrogate 21,442 human circRNAs to investigate differentially expressed circRNAs in cumulus cells, with potential target genes of significantly changed circRNAs and biological functions measured by microRNA support vector regression (mirSVR) and gene ontology (GO) analysis, with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. RESULT(S): A total of 1,032 circRNAs were identified that were differentially expressed in PCOS cumulus cells, including 311 circRNAs increase and 721 circRNAs decrease (fold change ≥2). Four aberrantly expressed circRNAs reached a statistically significant result after Bonferroni correction (with Bonferroni correction, only circRNAs for which P < .05/21,442 = 2.3 × 10-6 were considered statistically significant). Further analysis showed that aberrantly expressed circRNAs harbored microRNA binding sites, and some microRNAs were associated with PCOS. The GO and KEGG biological pathway analysis indicated that the genes with protein binding, mitotic nuclear envelope disassembly and metabolic pathways were statistically significantly enriched. CONCLUSION(S): Our data suggest that the aberrantly expressed circRNAs and their targeted genes might be associated with PCOS, providing new clues to find key diagnostic and therapeutic molecular biomarkers for PCOS patients.

IL-6 promotes endometrial cancer cells invasion and migration through signal transducers and activators of transcription 3 signaling pathway.

Interleukin (IL)-6 is the most well-known traditional activator of activating signal transducers and activators of transcription 3 (Stat3). They have been proved to promote cancer progression in several human cancers. However, their exact roles in endometrial cancer have not been elucidated clearly. In this study, we aimed to investigate the role of IL-6/Stat3 signaling pathway in human endometrial cancer cells invasion and migration. We demonstrated that Stat3 is activated in endometrial cancer cell lines. To investigate the role of Stat3 in endometrial cancer invasive capacity, we used Stat3 inhibitor Stattic and found that Stattic significantly inhibited the migration and invasion of endometrial cancer cells elevated by IL-6. Furthermore, we showed that Stat3 inhibitor significantly decreased the expression of MMP2 enhanced by IL-6, indicating that IL-6 promoted endometrial cancer invasion and migration by Stat3-induced MMP2 upregulation. Taken together, our findings indicate that targeting IL-6/Stat3 pathway might be a potentially effective therapeutic strategy for treating endometrial cancer.

Targeting hexokinase 2 inhibition promotes radiosensitization in HPV16 E7-induced cervical cancer and suppresses tumor growth.

In order to improve the sensitivity of cervical cancer cells to irradiation therapy, we targeted hexokinase 2 (HK2), the first rate-limiting enzyme of glycolysis, and explore its role in cervical cancer cells. We suppressed HK2 expression and/or function by shRNA and/or metformin and found HK2 inhibition enhanced cells apoptosis with accelerating expression of cleaved PARP and caspase-3. HK2 inhibition also induced much inferior proliferation of cervical cancer cells both in vitro and in vivo with diminishing expression of mTOR, MIB and MGMT. Moreover, HK2 inhibition altered the metabolic profile of cervical cancer cells to one less dependent on glycolysis with a reinforcement of mitochondrial function and an ablation of lactification ability. Importantly, cervical cancer cells contained HK2 inhibition displayed more sensitivity to irradiation. Further results indicated that HPV16 E7 oncoprotein altered the glucose homeostasis of cervical cancer cells into glycolysis by coordinately promoting HK2 expression and its downregulation of glycolysis. Taken together, our findings supported a mechanism whereby targeting HK2 inhibition contributed to suppress HPV16 E7-induced tumor glycolysis metabolism phenotype, inhibiting tumor growth, and induced apoptosis, blocking the cancer cell energy sources and ultimately enhanced the sensitivity of HPV(+) cervical cancer cells to irradiation therapy.

Prostaglandin E2 (PGE2) promotes proliferation and invasion by enhancing SUMO-1 activity via EP4 receptor in endometrial cancer.

Prostaglandin E2 (PGE2), a derivative of arachidonic acid, has been identified as a tumorigenic factor in many cancers in recent studies. Prostaglandin E synthase 2 (PTGES2) is an enzyme that in humans is encoded by the PTGES2 gene located on chromosome 9, and it synthesizes PGE2 in human cells. In our study, we selected 119 samples from endometrial cancer patients, with 50 normal endometrium tissue samples as controls, in which we examined the expression of PTGES2. Both immunohistochemistry (IHC) and Western blot analyses demonstrated that synthase PTGES2, which is required for PGE2 synthesis, was highly expressed in endometrium cancer tissues compared with normal endometrium. Stable PTGES2-shRNA transfectants were generated in Ishikawa and Hec-1B endometrial cancer cell lines, and transfection efficiencies were confirmed by RT-PCR and Western blot analyses. We found that PGE2 promoted proliferation and invasion of cells in Ishikawa and Hec-1B cells by cell counting kit-8 tests (CCK8) and transwell assays, respectively. PGE2 stimulation enhanced the expression of SUMO-1, via PGE2 receptor subtype 4 (EP4). Further analysis implicated the Wnt/ß-catenin signaling pathway function as the major mediator of EP4 and SUMO-1. The increase in SUMO-1 activity prompted the SUMOlyation of target proteins which may be involved in proliferation and invasion. These findings suggest SUMO-1 and EP4 as two potential targets for new therapeutic or prevention strategies for endometrial cancers.

Mutant p53 induces EZH2 expression and promotes epithelial-mesenchymal transition by disrupting p68-Drosha complex assembly and attenuating miR-26a processing.

The tumor suppressor p53 and the transcriptional repressor Enhancer of Zeste Homolog 2 (EZH2) have both been implicated in the regulation of epithelial-mesenchymal transition (EMT) and tumor metastasis via their impacts on microRNA expression. Here, we report that mutant p53 (mutp53) promotes EMT in endometrial carcinoma (EC) by disrupting p68-Drosha complex assembly. Overexpression of mutp53 has the opposite effect of wild-type p53 (WTp53), repressing miR-26a expression by reducing pri-miR-26a-1 processing in p53-null EC cells. Re-expression of miR-26a in mutp53 EC cells decreases cell invasion and promotes mesenchymal-epithelial transition (MET). Rescuing miR-26a expression also inhibits EZH2, N-cadherin, Vimentin, and Snail expression and induces E-cadherin expression both in vitro and in vivo. Moreover, patients with higher serum miR-26a levels have a better survival rate. These results suggest that p53 gain-of-function mutations accelerate EC tumor progression and metastasis by interfering with Drosha and p68 binding and pri-miR-26a-1 processing, resulting in reduced miR-26a expression and EZH2 overexpression.

Stem cell protein Piwil1 endowed endometrial cancer cells with stem-like properties via inducing epithelial-mesenchymal transition.

BACKGROUND: Stem cell protein Piwil1 functions as an oncogene in various tumor types. However, the exact function and mechanism of Piwil1 in endometrial cancer remains unclear. METHODS: The expression of Piwil1 and its relationships with clinicopathological factors were investigated using immunohistochemistry. Up- or down-regulation of Piwil1 were achieved by stable or transient transfection with plasmids or short hairpin RNA (shRNA). Effects of Piwil1 on cancer cells viability, invasion and migration were evaluated by MTT, plate colony formation, transwell assay and nude mouse tumor xenograft assay. The stem-like properties of endometrial cancer cells was detected by spheroid formation assay. Effects of Piwil1 on expression levels of target genes were detected by qRT-PCR, western blotting and Immunofluorescence. RESULTS: Compared with atypical hyperplasia and normal tissues, Piwil1 was much higher in endometrial carcinoma tissues. We found that Piwil1 expression was significantly correlated with FIGO stage, lymphovascular space involvement, lymph node metastasis and level of myometrial invasion. Overexpression of Piwil1 functioned to maintain stem-like characteristics, including enhancing tumor cell viability, migration, invasion and sphere-forming activity. Conversely, Piwil1 knockdown inhibited cell viability, migration, invasion, sphere-forming activity in vitro and tumor formation in xenograft model in vivo. Furthermore, study of the expression of epithelial and mesenchymal markers showed that Piwil1 was responsible for an EMT-like phenotype associated with an increase in mesenchymal markers and suppression of E-cadherin. Moreover, Piwil1 augmented expression levels of CD44 and ALDH1 expression, two known endometrial CSC markers, as well as other stemness-associated genes. CONCLUSIONS: Our results suggested that stem cell protein Piwil1 play important roles in regulating EMT and the acquisition of stem-like properties of endometrial cancer cells. Therefore, it indicated that Piwil1 may represent a promising target for developing a novel treatment strategy for endometrial cancer.

AMF/PGI-mediated tumorigenesis through MAPK-ERK signaling in endometrial carcinoma.

Autocrine motility factor (AMF), which is also known as phosphoglucose isomerase (PGI), enhances tumor cell growth and motility. In this study, we found that AMF and its receptor were both highly expressed in Endometrial Carcinoma (EC) tissues compared to normal tissues. Levels of AMF were increased in serum of endometrial cancer patients. Downregulation of AMF by shRNA inhibited invasion, migration and proliferation as well as growth in a three-dimensional culture. AMF cytokine function, but not enzymatic activity of PGI, regulated tumorigenic activities of AMF. The MAPK-ERK1/2 pathway contributed to AMF-induced effects in EC cells. In agreement, Mek inhibitor decreased AMF-induced invasion, migration and proliferation of EC cells. In addition, in two mouse tumor metastasis models (EC cells delivered through left ventricle or intraperitoneally) AMF-silenced EC cells showed decreased tumor proliferative and metastatic capacities. We suggest that AMF/PGI is a potential therapeutic target in endometrial carcinoma.

Autocrine motility factor promotes epithelial-mesenchymal transition in endometrial cancer via MAPK signaling pathway.

Autocrine motility factor (AMF) as a cytokine and a growth factor, is known to regulate tumor cell growth and motility in the progress of various human malignant tumors, however, its role in endometrial cancer (EC) has not been fully studied. In the present study, using immunohistochemistry, we found that AMF was highly expressed in EC tissues compared with normal endometrial tissues and tissue micrioarray technology showed positive correlation between AMF expression and epithelial-to-mesenchymal transition (EMT) related markers E-cadherin, vimentin and Snail. Next, we detected that silencing of AMF by stable transfection with shRNA induced mesenchymal-to-epithelial transition phenotype in Ishikawa and HEC-1B cells by qRT-PCR, western blotting and immunofluorescence. Gene expression profile revealed that AMF silencing resulted in altered expression of EMT related molecular mediators including Snail and transforming growth factor ß receptor 1, and involvement of mitogen-activated protein kinase (MAPK) signaling pathway. Additionally, we found that EMT related markers were downregulated with pretreatment of the MAPK-specific inhibitor U0126 by western blotting. The present study is the first to support a role for AMF mediating EMT in endometrial cancer through MAPK signaling. Therefore, AMF may provide a potential prognostic and therapeutic target in preventing EC progression.

Piwil1 causes epigenetic alteration of PTEN gene via upregulation of DNA methyltransferase in type I endometrial cancer.

Piwil1, a member of the Piwi family, has been well demonstrated to mediate tumorigenesis associated with DNA hypermethylation. It has been reported that Piwil1 is overexpressed in various types of cancer, including endometrial cancer. However, the underlying mechanism of Piwil1 in endometrial cancer remains largely unclear. PTEN exerts an important tumor suppressor role in endometrial carcinogenesis. The present study aimed to investigate whether Piwil1 could regulate the expression of PTEN. Herein, we found that Piwil1 could promote the loss of PTEN expression and increase aberrant hypermethylation of PTEN gene promoter in Ishikawa cells. We also found that Piwil1 could regulate the expression of DNA methyltransferase 1 (DNMT1). Silencing DNMT1 gene could upregulate the PTEN gene expression and change the methylation status of PTEN gene promoter in Ishikawa cells. These results suggested that Piwil1 caused the loss of PTEN expression through DNMT1-mediated PTEN hypermethylation. Taken together, these data provide a novel regulatory mechanism of Piwil1 in endometrial cancer.

Oncostatin M activates STAT3 to promote endometrial cancer invasion and angiogenesis.

Oncostatin M (OSM), a pleiotropic cytokine, can either promote or inhibit the growth of tumors derived from specific tissues. However, little is known about the activity and expression pattern of OSM in endometrial cancers (ECs). Herein we show that expression of OSM in human ECs was significantly higher than that in hyperplastic or normal tissues. In EC tissues, high OSM levels were positively correlated with tumor stage, histological grade, myometrial invasion, and lymph node metastasis. Additionally, we demonstrated that recombinant human OSM (rhOSM) promoted tumor angiogenesis in EC cell lines by activating STAT3 (signal transducer and activator of transcription 3) and enhanced both cell migration and cell invasion. rhOSM did not, however, influence the proliferation of EC cells in vitro. In contrast, in our in vivo xenograft model, overexpression of rhOSM promoted cell proliferation, tumor growth, and angiogenesis in nude mice. Collectively, these experiments suggest that OSM may be a tumor promoter that encourages EC progression. OSM may thus serve as a potential target of antiangiogenic therapy for endometrial cancer.