Mechanism and functional consequences of loss of FOXO1 expression in endometrioid endometrial cancer cells

Withaferin A suppressed hepatocellular carcinoma progression through inducing IGF2BP3/FOXO1/JAK2/STAT3 pathway-mediated ROS production

OBJECTIVE

This study aimed to investigate the underlying molecular mechanisms of Withaferin A (WA) in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

The gene and protein expression were analyzed using RT-qPCR and western blot, respectively. The proliferation of HCC cells was evaluated by CCK-8 assays. The migrative ability of HCC cells was measured by transwell assays.

RESULTS

We revealed that WA suppressed the proliferation and migration of HCC cells and inhibited IGF2BP3 (insulin like growth factor 2 mRNA binding protein 3) expression. IGF2BP3 abundance reversed the reactive oxygen species (ROS) accumulation and suppression of HCC cell proliferation and migration induced by WA. Besides, IGF2BP3 suppressed ROS production to promote the growth and migration of HCC cells. Furthermore, we found that IGF2BP3 exerted its tumor-promotive and ROS-suppressive effect on HCC cells by regulating the expression of FOXO1 (forkhead box O1). In addition, IGF2BP3-stimulated activation of JAK2 (Janus kinase 2)/STAT3 (signal transducer and activator of transcription 3) phosphorylation effectively decreased the transcription of FOXO1. FOXO1 abundance decreased the phosphorylation of JAK2 and STAT3 by increasing ROS level, forming a feedback loop for the inhibition of JAK2/STAT3 signaling activated by IGF2BP3.

CONCLUSIONS

WA-induced ROS inhibited HCC cell growth and migration through the inhibition of IGF2BP3 to deactivate JAK2/STAT3 signaling, resulting in increased FOXO1 expression to further stimulate ROS production and inhibit JAK2/STAT3 signaling.

Disrupted Balance of the Oxidant-Antioxidant System in the Pathophysiology of Female Reproduction: Oxidative Stress and Adverse Pregnancy Outcomes

The significance of oxidative stress in the pathophysiology of male reproductive processes has been closely studied in the last two decades. Recently, it has become clear that oxidative stress can lead to numerous pathological conditions during female reproductive processes as well, contributing to the development of endometriosis, polycystic ovary syndrome and various forms of infertility. During pregnancy, physiological generation of reactive oxygen species (ROS) occurs in association with several developmental processes including oocyte maturation and implantation. An overproduction of ROS can lead to disturbances in fetal development and increases the risk for missed abortion, intrauterine growth restriction, pre-eclampsia, premature delivery and gestational diabetes. Our review focuses on the etiological role of the disrupted oxidant-antioxidant system during human gestation as it relates to adverse pregnancy outcomes.

Clinicopathological correlations of endometrioid and clear cell carcinomas in the uterus and ovary

Endometrioid carcinoma (EC) and clear cell carcinoma (CC) are associated with endometrial tissue hyperplasia and endometriosis, and they occur in the endometrium and ovaries. However, detailed differences between these tumors based on immunostaining are unclear; therefore, in this study, we aimed to analyze the clinicopathological correlations between these tumors using immunostaining and to develop new treatments based on histological subtypes. Immunohistochemistry was used to investigate differentially expressed hypoxia-associated molecules (hypoxia-inducible factor-1 subunit alpha [HIF-1α], forkhead box O1, prostate-specific membrane antigen, signal transducer and activator of transcription 3 [STAT3], hepatocyte nuclear factor 1β [HNF-1β], aquaporin-3, and vimentin [VIM]) between these carcinomas because of the reported association between CC and ischemia. Immunostaining and clinicopathological data from 70 patients (21 uterine endometrioid carcinomas [UECs], 9 uterine cell carcinomas, 20 ovarian endometrioid carcinomas [OECs], and 20 ovarian cell carcinomas [OCCs]) were compared. HIF-1α and prostate-specific membrane antigen expression levels were higher in UEC and OCC than in uterine cell carcinomas and OEC. STAT3 was slightly overexpressed in UEC. Additionally, forkhead box O1 expression was either absent or significantly attenuated in all ECs. VIM and AQ3 were highly expressed in UEC, whereas HNF-1β expression was higher in OCC. UEC, OEC, and OCC were more common in the uterine fundus, left ovary, and right ovary, respectively. Ovarian endometriosis was strongly associated with EC. Our findings suggest that UEC and OCC share a carcinogenic pathway that involves HIF-1α induction under hypoxic conditions via STAT3 expression, resulting in angiogenesis. Furthermore, the anatomical position of carcinomas may contribute to their carcinogenesis. Finally, aquaporin-3 and VIM demonstrate strong potential as biomarkers for UEC, whereas HNF-1β expression is a crucial factor in CC development. These differences in tumor site and histological subtypes shown in this study will lead to the establishment of treatment based on histological and immunohistological classification.

Pictilisib-Induced Resistance Is Mediated through FOXO1-Dependent Activation of Receptor Tyrosine Kinases in Mucinous Colorectal Adenocarcinoma Cells

The phosphatidylinositol (PI3K)/AKT/mTOR axis represents an important therapeutic target to treat human cancers. A well-described downstream target of the PI3K pathway is the forkhead box O (FOXO) transcription factor family. FOXOs have been implicated in many cellular responses, including drug-induced resistance in cancer cells. However, FOXO-dependent acute phase resistance mediated by pictilisib, a potent small molecule PI3K inhibitor (PI3Ki), has not been studied. Here, we report that pictilisib-induced adaptive resistance is regulated by the FOXO-dependent rebound activity of receptor tyrosine kinases (RTKs) in mucinous colorectal adenocarcinoma (MCA) cells. The resistance mediated by PI3K inhibition involves the nuclear localization of FOXO and the altered expression of RTKs, including ErbB2, ErbB3, EphA7, EphA10, IR, and IGF-R1 in MCA cells. Further, in the presence of FOXO siRNA, the pictilisib-induced feedback activation of RTK regulators (pERK and pAKT) was altered in MCA cells. Interestingly, the combinational treatment of pictilisib (Pi3Ki) and FOXO1i (AS1842856) synergistically reduced MCA cell viability and increased apoptosis. These results demonstrate that pictilisib used as a single agent induces acute resistance, partly through FOXO1 inhibition. Therefore, overcoming PI3Ki single-agent adaptive resistance by rational design of FOXO1 and PI3K inhibitor combinations could significantly enhance the therapeutic efficacy of PI3K-targeting drugs in MCA cells.

Self-assembled DNA nanostructure containing oncogenic miRNA-mediated cell proliferation by downregulation of FOXO1 expression

FOXO1 transcription factor not only limits the cell cycle progression but also promotes cell death as a tumor suppressor protein. Though the expression of FOXO1 is largely examined in breast cancer, the regulation of FOXO1 by miRNA is yet to be explored. In the current study, self-assembled branched DNA (bDNA) nanostructures containing oncogenic miRNAs were designed and transfected to the MCF7 cell line to decipher the FOXO1 expression. bDNA containing oncogenic miRNAs 27a, 96, and 182 synergistically downregulate the expression of FOXO1 in MCF7 cells. The down-regulation is evident both in mRNA and protein levels suggesting that bDNA having miRNA sequences can selectively bind to mRNA and inhibit translation. Secondly, the downstream gene expression of p21 and p27 was also significantly downregulated in presence of miR-bDNA nanostructures. The cell proliferation activity was progressively increased in presence of miR-bDNA nanostructures which confirms the reduced tumor suppression activity of FOXO1 and the downstream gene expression. This finding can be explored to design novel bDNA structures which can downregulate the tumor suppressor proteins in normal cells and induce cell proliferation activity to identify early-phase markers of cancer.

Exosomal miRNA-21 from Toxoplasma gondii-infected microglial cells induces the growth of U87 glioma cells by inhibiting tumor suppressor genes

Toxoplasma gondii is an intracellular protozoan parasite that can modulate the microenvironment of infected hosts and is known to be associated with the incidence of brain tumor growth. In this study, we suggested that the exosomal microRNA-21 derived from Toxoplasma infection would contribute to the growth of brain tumors. Exosomes of BV2 microglial cells infected with Toxoplasma were characterized and confirmed internalization to U87 glioma cells. Exosomal miRNA expression profiles were analyzed using microRNA array and miR-21A-5p associated with Toxoplasma and tumor sorted. We also examined the mRNA level of tumor-associated genes in U87 glioma cells by changing the level of miR-21 within exosomes and the effects of exosomes on the proliferation of human U87 glioma cells. Expression of miRNA-21 was increased and anti-tumorigenic genes (FoxO1, PTEN, and PDCD4) were decreased in exosomes within T. gondii-infected U87 glioma cells. Toxoplasma-infected BV2-derived exosomes induced proliferation of U87 glioma cells. The exosomes induced the growth of U87 cells in a mouse tumor model. We suggest that the increased exosomal miR-21 from Toxoplasma-infected BV2 microglial cells may play an important role as a cell growth promotor of U87 glioma cells through a down-regulation of anti-tumorigenic genes.

Genistein induces long-term expression of progesterone receptor regardless of estrogen receptor status and improves the prognosis of endometrial cancer patients

Progesterone is used to treat uterine endometrial cancer in young patients wishing to preserve their fertility as well as in advanced or recurrent patients, but its response rate is limited. The antitumor effect of progesterone is mediated by progesterone receptor (PR) binding. Hence, loss of progesterone’s therapeutic effect, i.e., development of progesterone resistance, is mainly due to decreased PR expression. However, little is known about underlying mechanisms that regulate PR expression. Immunohistochemistry analysis of specimens from 31 young, endometrial cancer patients showed that elevated PR expression significantly increased (P < 0.05) rates of progression-free and overall survival. We investigated mechanisms of regulating PR expression and suppressing cell proliferation using genistein, a chemotherapeutic agent against different cancers. Genistein inhibits cell growth by inducing cell cycle arrest in G2 and apoptosis; moreover, it upregulates prolonged expression of PR-B and forkhead box protein O1, regardless of estrogen receptor alpha expression in endometrial cancer cells. Genistein-induced PR expression decreases CCAAT/enhancer binding protein beta expression and activates c-Jun N-terminal kinase pathway, rather than causing epigenetic alterations of the PR promoter. Therefore, increased PR expression is an important antitumor effect of genistein. This may help to improve the response rates of fertility-sparing treatments for young patients.

FOXO1 Gene Downregulation and Promoter Methylation Exhibits Significant Correlation With Clinical Parameters in Indian Breast Cancer Patients

Background: Forkhead box “O” one which is member of Forkhead box family of transcription factors is known to play key role in different physiological processes including cell cycle arrest, autophagy, and apoptosis. FOXO1 is defined to play tumor suppressive role in various malignancies including breast cancer and its Dysregulation is frequently reported. However, the evaluation of FOXO1 promoter methylation and its expression at mRNA and protein level in different stages of breast cancer and its association with different clinical parameters is still not studied. Therefore, for better understanding the role of FOXO1 in breast cancer, in our study we examined the FOXO1 mRNA and protein expression in Breast cancer samples of Indian breast cancer patients.

Results: Total 127 breast cancer samples along with adjacent normal tissue (n = 127) were analyzed through methylation specific PCR (MS-PCR), mRNA expression (Real-time PCR) and Immunohistochemistry (IHC). We detected 69.29% cases to be downregulated at the mRNA level, and 77.95% of cases exhibited no or low protein expression. In our data we report a significant association (p = 0.0001) between the downregulated protein expression and promoter hypermethylation of FOXO1 gene. We also found a significant correlation of FOXO1 mRNA level with Age (p = 0.008), age at first live birth (p = 0,003), tumor size (p = 0.05) and lymph node status (p = 0.01).

Conclusion: we in our study report the tumor suppressive role of FOXO1 in case of Indian breast cancer patients and our data suggest it to exhibit prognostic importance. However, further research is needed to evaluate FOXO1 significance in diagnostic and therapeutic targeting in breast cancer cases.

Construction and validation of a novel aging-related gene signature and prognostic nomogram for predicting the overall survival in ovarian cancer

BACKGROUND

Ovarian cancer (OC) is the most lethal gynecological malignancy. The objective of this study was to establish and validate an individual aging-related gene signature and a clinical nomogram that can powerfully predict independently the overall survival rate of patients with ovarian cancer.

METHODS

Data on transcriptomic profile and relevant clinical information were retrieved from The Cancer Genome Atlas (TCGA) database as a training group, and the same data from three public Gene Expression Omnibus (GEO) databases as validation groups. Univariate Cox regression analysis, lasso regression analysis, and multiple multivariate Cox analysis were analyzed sequentially to select the genes to be included in the aging-associated signature. A risk scoring model was established and verified, the predictive value of the model was evaluated, and a clinical nomogram was established.

RESULTS

We found eight genes that were most relevant to prognosis and constructed an eight-mRNA signature. Based on the model, each OC patient's risk score was able to be calculated and patients were split into groups of low and high risks with a distinct outcome. Survival analysis confirmed that the outcome of patients in the high-risk group was dramatically shorter than that of those in the low-risk group, and the eight-mRNA signature can be considered as a powerful and independent predictor that could predict the outcome of OC patient. Additionally, the risk score and age can be used to construct a clinical nomogram as a simpler tool for predicting prognosis. We also explored the association between the risk score and immunity and drug sensitivity.

CONCLUSION

This study suggested that the aging-related gene signature could be used as an intervention point and latent prognostic predictor in OC, which may provide new perceptions for postoperative treatment strategies.

The Role of Oxidative Stress and Antioxidant Balance in Pregnancy

It has been widely known that oxidative stress disrupts the balance between reactive oxygen species (ROS) and the antioxidant system in the body. During pregnancy, the physiological generation of ROS is involved in a variety of developmental processes ranging from oocyte maturation to luteolysis and embryo implantation. While abnormal overproduction of ROS disrupts these processes resulting in reproductive failure. In addition, excessive oxidative stress impairs maternal and placental functions and eventually results in fetal loss, IUGR, and gestational diabetes mellitus. Although some oxidative stress is inevitable during pregnancy, a balancing act between oxidant and antioxidant production is necessary at different stages of the pregnancy. The review aims to highlight the importance of maintaining oxidative and antioxidant balance throughout pregnancy. Furthermore, we highlight the role of oxidative stress in pregnancy-related diseases.

Clinical Evaluation of FOXO1 as a Tumor Suppressor in Prostate Cancer

Objective

Prostate cancer (PCa) is considered the most serious cancer in the world. Nevertheless, the accuracy of current biomarkers, such as pathological staging, Gleason's score, and serum prostate-specific antigen (PSA) levels, is limited. FOXO1 is a key downstream effector of PTEN and a tumor suppressor in PCA, which has been reported extensively. However, the clinical relevance of FOXO1 in PCa remains unclear.

Methods

In this study, we first detected its expression in four public databases to explore the clinical role of FOXO1. Verification of the knockdown effect of FOXO1 siRNA was performed by real-time PCR analysis. Changes in cell viability were assessed using cell counting kit-8 (CCK-8) assays. In addition, we verified the effect of FOXO1 on the PCa cell cycle using a cell cycle assay.

Results

Herein, we found that FOXO1 was significantly downregulated in PCa tissues and was significantly associated with Gleason's score, age, biochemical recurrence (BCR), and lymph node (LN) status, while FOXO1 expression was independent of pathological staging and preoperative PSA levels. The Kaplan-Meier survival analysis showed that PCA patients with high FOXO1 expression were less likely to develop BCR compared with patients with low FOXO1 expression. In terms of function, FOXO1 inhibition significantly promoted the proliferation and cell cycle progression of PCa cells.

Conclusions

In summary, our study suggests that FOXO1 may be one of the prognostic factors that describe the risk of PCa for BCR. These results suggest that FOXO1 may be a therapeutic target for PCa.

Sevoflurane promotes the apoptosis of laryngeal squamous cell carcinoma in-vitro and inhibits its malignant progression via miR-26a/FOXO1 axis

Laryngeal squamous cell carcinoma (LSCC) is a laryngeal malignancy with a high mortality rates, and its treatment remains difficult. Sevoflurane is a surgical anesthesia which has anti-tumor effect. This investigation assessed the effects of LSCC cells treatment with Sevoflurane in vitro and in vivo. Hep-2 and Tu177 cells, human LSCC samples and BALB/C nude mice were used for result assessments. Cell viability, proliferation, migration and invasion were assessed via Cell Count Kit-8, wound healing assay and transwell invasion assay respectively. MiR-26a and FOXO1 expressions was examined by qRT-PCR. FOXO1, E-cadherin, N-cadherin and vimentin activities were examined by Western blotting. Moreover, animal experiments were performed to verify our findings in vitro. Lastly, miR-26a and FOXO1 expression levels in clinical samples were analyzed. According to the results, Sevoflurane decreased LSCC cells’ viability and even stimulated their apoptosis in vitro and in vivo. Moreover, it could reduce the migration, invasion and EMT. Mechanistically, sevoflurane could downregulate miR-26a expression and that miR-26a could negatively modulate FOXO1 activity. Thus, sevoflurane could increase FOXO1 activity. In the clinical samples, miR-26a expression was significantly upregulated, but FOXO1 was remarkably down-regulated and miR-26a expression in LSCC was linked with better prognosis. In conclusion, MiR-26a is increased and FOXO1 is reduced in human LSCC, Sevoflurane inhibits proliferation and mediates apoptosis of LSCC cells. Further, MiR-26a binds FOXO1 directly, and FOXO1 expression is down-regulated by Sevoflurane. Finally, Sevoflurane triggers LSCC cells apoptosis in vivo. Sevoflurane use to target miR-26a/FOXO1 may be a novel alternative for LSCC therapy.

Identification of Potential Therapeutic Genes and Pathways in Phytoestrogen Emodin Treated Breast Cancer Cell Lines via Network Biology Approaches

Phytoestrogens have been investigated for their potential anti-tumorigenic effects in various cancers including breast cancer. Emodin being a phytoestrogen shows anti-carcinogenic properties especially in estrogen receptor positive (ER+) breast cancers. The aim of this study is to identify the molecular mechanism and related biological pathways in both (ER+) MCF-7 and (ER-) MDA-MB-231 breast cancer cell lines upon Emodin treatment via microarray analysis in order to find out therapeutic biomarkers. In both cell lines, first differentially expressed genes were identified, then gene ontology and functional pathway enrichment analyses were performed. Genes regulated through multiple pathways were studied together with literature and a gene cluster was determined for each cell line. Further GeneMANIA and STRING databases were used to study the interactions within the related gene clusters. The results showed that, the genes which are related to cell cycle were significantly regulated in both cell lines. Also, Forkhead Box O1-related genes were found to be prominent in MCF-7 cells. In MDA-MB-231 cells, spindle attachment checkpoint mechanism-related genes were regulated, remarkably. As a result, novel gene regulations reported in this study in response to Emodin will give more information about its metabolism and antiproliferative effect, especially in ER + cells.

Skp2 Deteriorates the Uterine Receptivity by Interacting with HOXA10 and Promoting its Degradation

Receptive endometrium plays a core role in successful embryo implantation, and about one-third of repeated embryo implantation failures are attributed to endometrial receptive defects. S-phase kinase-associated protein 2 (SKP2), a member of the F-box protein family, plays an important role in many cellular processes, including cell proliferation and apoptosis. However, its role in endometrial receptivity is still unclear. Here, we identified SKP2 was obviously upregulated in the patients with infertility. Functional study showed that SKP2 overexpression inhibited endometrial epithelial cell (EEC) proliferation, whereas SKP2 knockdown promoted the proliferation of EECs. In addition, the overexpression of SKP2 also repressed adhesion rate of embryonic cells to EECs. In vivo studies further suggested that the upregulation of SKP2 obviously suppressed endometrium receptivity formation and embryo implantation potential. Mechanistical study clarified that SKP2 directly interacted with HOXA10 and decreased protein stability through promoting the ubiquitin-mediated proteasome degradation of HOXA10. In conclusion, the current study documented that the high expression of SKP2 deteriorates endometrial receptivity formation by decreasing the HOXA10 expression and suggested that SKP2 may be defined as a marker of endometrial receptivity, and as a target for the diagnosis and treatment of infertility.

An integration analysis of mRNAs and miRNAs microarray data to identify key regulators for ovarian endometriosis based on competing endogenous RNAs

This study aimed to uncover effects of non-coding RNA transcripts on ovarian endometriosis (OEM) development. Two transcription datasets (GSE105764 and GSE105765) about OME were downloaded from Gene Expression Omnibus (GEO) database and the differentially expressed mRNAs, lncRNAs and miRNAs (DEmRNAs, DElncRNAs and DEmiRNAs) between OEM cases and controls were identified followed by protein-protein interaction analysis. Then, co-expression analysis was conducted and DEmiRNAs-DEmRNAs as well as DElncRNAs-DEmiRNAs pairs were predicted to construct the ceRNA network followed by sub-ceRNA network associated with OEM extraction. Functional analyses of DEmRNAs in ceRNA and sub-module network and the survival analysis were also performed to evaluate the correlation of key regulators and OV outcomes. Totally, 1910 DEmRNAs, 158 DElncRNAs and 118 DEmiRNAs were screened between OEM cases and controls and the functional analyses of DEmRNAs showed that they were significantly enriched in cell adhesion. Furthermore, there were 505 nodes in PPI network and ceRNA network included 762 interaction pairs among 357 DEmRNAs, 28 DElncRNAs and 24 DEmiRNAs. The KEGG analysis suggested several genes including FOXO1, STAT5A and RUNX1 were predominately associated with pathways in cancer while IL15 was primarily enriched in cytokine-cytokine receptor interaction pathway. Importantly, these two pathways were also found to be implicated with OEM development. Finally, survival analysis implied that overexpression of ZFPM2-AS1 had a good clinical outcome while the under-expression levels of FOXO1, JUP, STAT5A, RUNX1 and PRKG1-AS1 exhibited a better prognosis for OV. FOXO1, STAT5A, RUNX1 and IL15, PRKG1-AS1 and ZFPM2-AS1 were promising diagnostic makers for OME.

Prognostic implications of forkhead box protein O1 (FOXO1) and paired box 3 (PAX3) in epithelial ovarian cancer

BACKGROUND

Transcription factors forkhead box protein O1 (FOXO1) and paired box 3 (PAX3) have been reported to play important roles in various cancers. However, their role in epithelial ovarian cancer (EOC) has not been elucidated yet. Therefore, we evaluated the expression and clinical significance of FOXO1 and PAX3 in EOC.

METHODS

Immunohistochemical analyses of FOXO1 and PAX3 in 212 EOCs, 57 borderline ovarian tumors, 153 benign epithelial ovarian tumors, and 79 nonadjacent normal epithelial tissues were performed using tissue microarray. Various clinicopathological variables, including the survival of EOC patients, were compared. In addition, the effect of FOXO1 on cell growth was assessed in EOC cell lines.

RESULTS

FOXO1 and PAX3 protein expression levels were significantly higher in EOC tissues than in nonadjacent normal epithelial tissues, benign tissues, and borderline tumors (all p < 0.001). In EOC tissues, FOXO1 expression was positively correlated with PAX3 expression (Spearman's rho = 0.118, p = 0.149). Multivariate survival analysis revealed that high FOXO1 expression (hazard ratio = 2.77 [95% CI, 1.48-5.18], p = 0.001) could be an independent prognostic factor for overall survival. Most importantly, high expression of both FOXO1 and PAX3 showed a high hazard ratio (4.60 [95% CI, 2.00-10.55], p < 0.001) for overall survival. Also in vitro results demonstrated that knockdown of FOXO1 was associated with decreased cell viability, migration, and colony formation.

CONCLUSIONS

This study revealed that high expression of FOXO1/PAX3 is an indicator of poor prognosis in EOC. Our results suggest the promising potential of FOXO1 and PAX3 as prognostic and therapeutic markers. The possible link between biological functions of FOXO1 and PAX3 in EOC warrants further studies.

Genome-wide association and epidemiological analyses reveal common genetic origins between uterine leiomyomata and endometriosis

Uterine leiomyomata (UL) are the most common neoplasms of the female reproductive tract and primary cause for hysterectomy, leading to considerable morbidity and high economic burden. Here we conduct a GWAS meta-analysis in 35,474 cases and 267,505 female controls of European ancestry, identifying eight novel genome-wide significant (P < 5 × 10^-8) loci, in addition to confirming 21 previously reported loci, including multiple independent signals at 10 loci. Phenotypic stratification of UL by heavy menstrual bleeding in 3409 cases and 199,171 female controls reveals genome-wide significant associations at three of the 29 UL loci: 5p15.33 (TERT), 5q35.2 (FGFR4) and 11q22.3 (ATM). Four loci identified in the meta-analysis are also associated with endometriosis risk; an epidemiological meta-analysis across 402,868 women suggests at least a doubling of risk for UL diagnosis among those with a history of endometriosis. These findings increase our understanding of genetic contribution and biology underlying UL development, and suggest overlapping genetic origins with endometriosis.

Forced FoxO1:S249V expression suppressed glioma cell proliferation through G2/M cell cycle arrests and increased apoptosis

OBJECTIVE

Forkhead box O1 (FoxO1) plays a crucial role in the development of many tumors. Cyclin D kinase (CDK) 1 could influence the nuclear export and activity of FoxO1 through phosphorylation of serine (S)²⁴⁹. However, the effects of S²⁴⁹ phosphorylation in the development of glioma remain unclear. The aim of the present study is to assess the function of FoxO1:S²⁴⁹V mutant, which was converted S²⁴⁹ phosphorylation site into valine (V) residues in the glioma development.

METHODS

FoxO1-knockdown U251 glioma cells (U251-KD cells) were established by infection of retrovirus particles with FoxO1 siRNA and FoxO1 restored cells (FoxO1:S²⁴⁹V) were obtained by re-introduction of FoxO1:S²⁴⁹V cDNA. We detected mRNA expression by real-time PCR, and cell cycle arrest and apoptosis by flow cytometric assay, and cell proliferation by BrdU assay and CCK-8 assay. The protective effects of FoxO1:S²⁴⁹V were detected by the xenograft tumor formation assay.

RESULTS

The FoxO1 mRNA expression was significantly decreased in the glioma specimens (n = 24). The U251-KD cells showed downregulation of p27 and Bim, while the phosphorylation of CDK1 was upregulated. FoxO1:S²⁴⁹V cells inhibited the phosphorylation of S²⁴⁹, and induced G2/M cell cycle arrest, following reduced cell growth and increased apoptosis. Moreover, FoxO1:S²⁴⁹V expression effectively inhibits the glioma growth.

CONCLUSION

Our findings suggest that the forced FoxO1:S²⁴⁹V suppressed the cell growth through G2/M cell cycle arrests and increased apoptosis in glioma.

A novel and compact review on the role of oxidative stress in female reproduction

In recent years, the study of oxidative stress (OS) has become increasingly popular. In particular, the role of OS on female fertility is very important and has been focused on closely. The occurrence of OS is due to the excessive production of reactive oxygen species (ROS). ROS are a double-edged sword; they not only play an important role as secondary messengers in many intracellular signaling cascades, but they also exert indispensable effects on pathological processes involving the female genital tract. ROS and antioxidants join in the regulation of reproductive processes in both animals and humans. Imbalances between pro-oxidants and antioxidants could lead to a number of female reproductive diseases. This review focuses on the mechanism of OS and a series of female reproductive processes, explaining the role of OS in female reproduction and female reproductive diseases caused by OS, including polycystic ovary syndrome (PCOS), endometriosis, preeclampsia and so on. Many signaling pathways involved in female reproduction, including the Keap1-Nrf2, NF-κB, FOXO and MAPK pathways, which are affected by OS, are described, providing new ideas for the mechanism of reproductive diseases.

Non-Coding RNAs in Endometrial Physiopathology

The Human Genome Project led to the discovery that about 80% of our DNA is transcribed in RNA molecules. Only 2% of the human genome is translated into proteins, the rest mostly produces molecules called non-coding RNAs, which are a heterogeneous class of RNAs involved in different steps of gene regulation. They have been classified, according to their length, into small non-coding RNAs and long non-coding RNAs, or to their function, into housekeeping non-coding RNAs and regulatory non-coding RNAs. Their involvement has been widely demonstrated in all cellular processes, as well as their dysregulation in human pathologies. In this review, we discuss the function of non-coding RNAs in endometrial physiology, analysing their involvement in embryo implantation. Moreover, we explore their role in endometrial pathologies such as endometrial cancer, endometriosis and chronic endometritis.

Long noncoding RNA LINC00261 regulates endometrial carcinoma progression by modulating miRNA/FOXO1 expression

Long noncoding RNA LINC00261 was reported to be downregulated in multiple cancers. LINC00261 overexpression inhibits cancer cell proliferation, migration, and invasion. But the expression and function of LIN00261 in endometrial carcinoma are still elusive. We found that LINC00261 mRNA levels were downregulated in endometrial carcinoma, and LINC00261 overexpression inhibited endometrial carcinoma cell proliferation, migration, and invasion. miRNAs, including miR-182, miR-183, miR-153, miR-27a, and miR-96, were predicted to bind LINC00261 and FOXO1, and functioned to attenuate expression of LINC00261 and FOXO1. Overexpressed LINC00261 lowered these dissociative miRNAs, resulting in increase of FOXO1 protein levels. The knockdown of FOXO1 eliminated the suppression effect of overexpressed LINC00261 on endometrial carcinoma cell aggressiveness. LINC00261 promotes FOXO1 expression through reducing FOXO1-targeted miRNAs to suppress endometrial carcinoma cell proliferation, migration, and invasion.

SIGNIFICANCE OF THE STUDY

LINC00261 is downregulated in endometrial carcinoma and associated with metastasis of this cancer. LINC00261 elevates FOXO1 protein levels through reducing FOXO1-targeted miRNAs to suppress endometrial carcinoma cell proliferation, migration, and invasion.

FOXO1: Another avenue for treating digestive malignancy?

Digestive malignancies are the leading cause of mortality among all neoplasms, contributing to estimated 3 million deaths in 2012 worldwide. The mortality rate hassurpassed lung cancer and prostate cancer in recent years. The transcription factor Forkhead Box O1 (FOXO1) is a key member of Forkhead Box family, regulating diverse cellular functions during tumor initiation, progression and metastasis. In this review, we focus on recent studies investigating the antineoplastic role of FOXO1 in digestive malignancy. This review aims to serve as a guide for further research and implicate FOXO1 as a potent therapeutic target in digestive malignancy.

Assessing Estrogen-Induced Proliferative Response in an Endometrial Cancer Cell Line Using a Universally Applicable Methodological Guide

Objective

Translational endometrial cancer (EC) research benefits from an in vitro experimental approach using EC cell lines. We demonstrated the steps that are required to examine estrogen-induced proliferative response, a simple yet important research question pertinent to EC, and devised a pragmatic methodological workflow for using EC cell lines in experimental models.

Methods

Comprehensive review of all commercially available EC cell lines was carried out, and Ishikawa cell line was selected to study the estrogen responsiveness with HEC1A, RL95-2, and MFE280 cell lines as comparators where appropriate, examining relevant differential molecular (steroid receptors) and functional (phenotype, anchorage-independent growth, hormone responsiveness, migration, invasion, and chemosensitivity) characteristics in 2-dimensional and 3-dimensional cultures in vitro using immunocytochemistry, immunofluorescence, quantitative polymerase chain reaction, and Western blotting. In vivo tumor, formation, and chemosensitivity were also assessed in a chick chorioallantoic membrane model.

Results

Short tandem repeat analysis authenticated the purchased cell lines, whereas gifted cells deviated significantly from the published profile. We demonstrate the importance of prior assessment of the suitability of each cell line for the chosen in vitro experimental technique. Prior establishment of baseline, nonenriched conditions was required to induce a proliferative response to estrogen. The chorioallantoic membrane model was a suitable in vivo multicellular animal model for EC for producing rapid and reproducible data.

Conclusions

We have developed a methodological guide for EC researchers when using endometrial cell lines to answer important translational research questions (exemplified by estrogen-responsive cell proliferation) to facilitate robust data, while saving time and resources.

Mechanisms controlling the anti-neoplastic functions of FoxO proteins

The Forkhead box O (FoxO) proteins comprise a family of evolutionarily conserved transcription factors that predominantly function as tumor suppressors. These proteins assume diverse roles in the cellular anti-neoplastic response, including regulation of apoptosis and autophagy, cancer metabolism, cell-cycle arrest, oxidative stress and the DNA damage response. More recently, FoxO proteins have been implicated in cancer immunity and cancer stem-cell (CSC) homeostasis. Interestingly, in some sporadic sub-populations, FoxO protein function may also be manipulated by factors such as β-catenin whereby they instead can facilitate cancer progression via maintenance of CSC properties or promoting drug resistance or metastasis and invasion. This review highlights the essential biological functions of FoxOs and explores the areas that may be exploited in FoxO protein signaling pathways in the development of novel cancer therapeutic agents.

Marine Sponge Natural Products with Anticancer Potential: An Updated Review

Despite the huge investment into research and the significant effort and advances made in the search for new anticancer drugs in recent decades, cancer cure and treatment continue to be a formidable challenge. Many sources, including plants, animals, and minerals, have been explored in the oncological field because of the possibility of identifying novel molecular therapeutics. Marine sponges are a prolific source of secondary metabolites, a number of which showed intriguing tumor chemopreventive and chemotherapeutic properties. Recently, Food and Drug Administration-approved drugs derived from marine sponges have been shown to reduce metastatic breast cancer, malignant lymphoma, and Hodgkin's disease. The chemopreventive and potential anticancer activity of marine sponge-derived compounds could be explained by multiple cellular and molecular mechanisms, including DNA protection, cell-cycle modulation, apoptosis, and anti-inflammatory activities as well as their ability to chemosensitize cancer cells to traditional antiblastic chemotherapy. The present article aims to depict the multiple mechanisms involved in the chemopreventive and therapeutic effects of marine sponges and critically explore the limitations and challenges associated with the development of marine sponge-based anticancer strategy.

A guide for endometrial cancer cell lines functional assays using the measurements of electronic impedance

Endometrial cancer cell lines are critical tools to investigate the molecular mechanism of tumorigenesis using the end point cell-based assay such as proliferation, cytotoxicity, apoptosis, anoikis or migration and invasion. The proper assay optimization and performance is essential for physiologically relevant results interpretation. In this study we use label-free real-time cell analysis platform (xCELLigence) to optimize growing conditions for proliferation and migration experiments of two types of endometrial cancer cell lines HEC-1-B, HEC-1-A, KLE, and Ishikawa. Profiling of cell lines by cell index measurement in proliferation and migration experiments was performed. Our experimental approach allowed us to monitor particular stage of the cell growth, to see the relation between seeding density and dynamic cell growth as well as to choose the optimal serum concentration as chemoattractant in migration experiment. The highest rate of proliferation was shown for Ishikawa cells. The rapid pace of cellular migration was observed in case of KLE and HEC-1-B cells as compared to weak migratory activity of Ishikawa cells. The cell index that reflects the cell status characterized real-time cytological profile of each analyzed cell line. These cell profiles were crucial for better planning the classical end-point assays used in further research.

Posttranscriptional regulation of FOXO expression: microRNAs and beyond

Forkhead box, class O (FOXO) transcription factors are major regulators of diverse cellular processes, including fuel metabolism, oxidative stress response and redox signalling, cell cycle progression and apoptosis. Their activities are controlled by multiple posttranslational modifications and nuclear-cytoplasmic shuttling. Recently, post-transcriptional regulation of FOXO synthesis has emerged as a new regulatory level of their functions. Accumulating evidence suggests that this post-transcriptional mode of regulation of FOXO activity operates in response to stressful stimuli, including oxidative stress. Here, we give a brief overview on post-transcriptional regulation of FOXO synthesis by microRNAs (miRNAs) and by RNA-binding regulatory proteins, human antigen R (HuR) and quaking (QKI). Aberrant post-transcriptional regulation of FOXOs is frequently connected with various disease states. We therefore discuss characteristic examples of FOXO regulation at the post-transcriptional level under various physiological and pathophysiological conditions, including oxidative stress and cancer. The picture emerging from this summary points to a diversity of interactions between miRNAs/miRNA-induced silencing complexes and RNA-binding regulatory proteins. Better insight into these complexities of post-transcriptional regulatory interactions will add to our understanding of the mechanisms of pathological processes and the role of FOXO proteins.

LINKED ARTICLES

This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc.

Role of FoxO1 and apoptosis in pulmonary vascular remolding in a rat model of chronic thromboembolic pulmonary hypertension

To explore the role of FoxO1 and apoptosis in a rat model of chronic thromboembolic pulmonary hypertension (CTEPH). Rats were randomly divided into a sham group (n = 45) and an experimental group (n = 45). Autologous blood clots were injected into rats three times to induce CTEPH. Rats were further divided into three subgroups: a 1-week subgroup (n = 15), a 2-week subgroup (n = 15), and a 4-week subgroup (n = 15). Mean pulmonary arterial pressure (mPAP) and histopathology were evaluated at each time point. FoxO1, Bad, and Bcl-2 levels were examined at each time point using reverse transcription PCR and western blotting. The mPAP and vessel wall area/total area (WA/TA) ratio in the experimental group gradually increased in a time-dependent manner (P < 0.05). Both the mRNA and protein levels of FoxO1 decreased in the CTEPH rats compared to in the sham group. In addition, embolization led to the up-regulation of Bad and the down-regulation of Bcl-2 (P < 0.05). FoxO1 and apoptosis play an important role in the pathogenesis of CTEPH. Apoptosis-resistant pulmonary artery endothelial cells may play an important role in remodeling of the rat pulmonary artery.

Forkhead transcription factor 1 inhibits endometrial cancer cell proliferation via sterol regulatory element-binding protein 1

The morbidity and mortality associated with endometrial cancer (EC) has increased in recent years. Regarded as a tumor suppressor, forkhead transcription factor 1 (FOXO1) has various biological activities and participates in cell cycle progression, apoptosis and differentiation. Notably, FOXO1 also functions in the regulation of lipogenesis and energy metabolism. Lipogenesis is a feature of cancer and is upregulated in EC. Sterol regulatory element-binding protein 1 (SREBP1) is a transcription factor that is also able to regulate lipogenesis. Increased expression of SREBP1 is directly correlated with malignant transformation of tumors. A previous study demonstrated that SREBP1 was highly expressed in EC and directly resulted in tumorigenesis. However, the association between FOXO1 and SREBP1 in EC is not clear. In the present study, lentiviruses overexpressing FOXO1 were used in cell transfection and transduction. Cell viability assays demonstrated that the overexpression of FOXO1 was able to suppress cell proliferation significantly in Ishikawa and AN3 CA cell lines. In addition, FOXO1 overexpression significantly inhibited cell migration and invasion ability in vitro. In xenograft models, overexpression of FOXO1 suppressed cell tumorigenesis, and western blot analysis demonstrated that SREBP1 expression was markedly reduced in the FOXO1-overexpressing cells. It may therefore be concluded that FOXO1 is able to inhibit the proliferative capacity of cells in vitro and in vivo, in addition to the migratory and invasive capacities in vitro by directly targeting SREBP1.

Metformin inhibits estrogen-dependent endometrial cancer cell growth by activating the AMPK-FOXO1 signal pathway

Metformin is an oral biguanide commonly used for treating type II diabetes and has recently been reported to possess antiproliferative properties that can be exploited for the prevention and treatment of a variety of cancers. The mechanisms underlying this effect have not been fully elucidated. Our study shows a marked loss of AMP-activated protein kinase (AMPK) phosphorylation and nuclear human Forkhead box O1 (FOXO1) protein in estrogen-dependent endometrial cancer (EC) tumors compared to normal control endometrium. Metformin treatment suppressed EC cell growth in a time-dependent manner in vitro; this effect was cancelled by cotreatment with an AMPK inhibitor, compound C. Metformin decreased FOXO1 phosphorylation and increased FOXO1 nuclear localization in Ishikawa and HEC-1B cells, with non-significant increase in FOXO1 mRNA expression. Moreover, compound C blocked the metformin-induced changes of FOXO1 and its phosphorylation protein, suggesting that metformin upregulated FOXO1 activity by AMPK activation. Similar results were obtained after treatment with insulin. In addition, transfection with siRNA for FOXO1 cancelled metformin-inhibited cell growth, indicating that FOXO1 mediated metformin to inhibit EC cell proliferation. A xenograft mouse model further revealed that metformin suppressed HEC-1B tumor growth, accompanied by downregulated ki-67 and upregulated AMPK phosphorylation and nuclear FOXO1 protein. Taken together, these data provide a novel mechanism of antineoplastic effect for metformin through the regulation of FOXO1, and suggest that the AMPK-FOXO1 pathway may be a therapeutic target to the development of new antineoplastic drugs.

MicroRNA networks in pulmonary arterial hypertension: share mechanisms with cancer?

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a rare disease with poor prognosis and no therapeutics. PAH is characterized by severe remodeling of precapillary pulmonary arteries, leading to increased vascular resistance, pulmonary hypertension compensatory right ventricular hypertrophy, then heart failure and death. PAH pathogenesis shares similarities with carcinogenesis such as excessive cell proliferation, apoptosis resistance, metabolic shifts, or phenotypic transition. Although PAH is not a cancer, comparison of analogous mechanisms between PAH and cancer led to the concept of a cancer-like disease to emerge. MicroRNAs (miRNAs) are small noncoding RNAs involved in the regulation of posttranscriptional gene expression. miRNA dysregulations have been reported as promoter of the development of various diseases including cancers.

RECENT FINDINGS

Recent studies revealed that miRNA dysregulations also occur in PAH pathogenesis. In PAH, different miRNAs have been implicated to be the main features of PAH pathophysiology (in pulmonary inflammation, vascular remodeling, angiogenesis, and right heart hypertrophy).

SUMMARY

The review summarizes the implication of miRNA dysregulation in PAH development and discusses the similarities and differences with those observed in cancers.

Involvement of Numb-mediated HIF-1α inhibition in anti-proliferative effect of PNA-antimiR-182 in trastuzumab-sensitive and -resistant SKBR3 cells

Trastuzumab is a humanized monoclonal antibody against the human epidermal growth factor receptor 2 (HER2) that is overexpressed in about 25 % of breast cancer patients. However, primary and/or acquired resistance to trastuzumab develops in most affected persons. In this study, we explored the functional role of miR-182 inhibition with aiming the sensitization of SKBR3 cells to trastuzumab. Cell viability, apoptosis, colony formation, and migration capacities of SKBR3(S) (sensitive) and SKBR3(R) (resistant) cells were assessed to determine the anti-proliferative effects of PNA-antimiR-182. In addition, the expression levels of miR-182, mRNA of FOXO1, and Bim as well as the protein levels of HER2 and Notch1 signaling factors were evaluated by stem-loop RT-qPCR, RT-qPCR, and Western blot, respectively. The results indicated that miR-182 might play a causal role in the mechanism of trastuzumab. In line with that, PNA-antimiR-182 inhibited synergistically the viability of both the sensitive and resistant cell groups. Furthermore, the inhibitory effect of PNA-anitmiR-182 on migration in SKBR3 cells was more than the induction of apoptosis. In addition, PNA-antimiR-182 reduced the levels of NICD, Hes1, HIF-1α, and p-Akt in both cell groups, while it augmented the intracellular content of FOXO1 and Numb suppressor proteins. In other words, PNA-antimiR-182-mediated upregulation of Numb was associated with downregulation of HIF-1α and Hes1. Consequently, downregulation of miR-182 might find therapeutical value for overcoming trastuzumab resistance. Graphical Abstract The crosstalk between HER2 and Notch1 signaling pathway is mediated by miR-182.

Akt regulates progesterone receptor B-dependent transcription and angiogenesis in endometrial cancer cells

Progestins have long been used clinically for the treatment of endometrial cancers, however, the response rates to progestin therapy vary and the molecular mechanisms behind progestin insensitivity are poorly understood. We hypothesized that in PTEN mutated endometrial cancers, hyperactive Akt signaling downregulates Progesterone Receptor B (PRB) transcriptional activity, leading to overall impaired progestin responses. We report that inhibition of Akt with the Akt inhibitor, MK-2206 (MK), in conjunction with progestin (R5020) treatment, is sufficient to upregulate a subset of PRB target genes in Ishikawa cells stably expressing PRB (PRB-Ishikawa). Through gene ontology analysis of Akt-regulated PRB target genes, angiogenesis was found to be the principle process regulated by Akt-PRB. To further interrogate the mechanism by which Akt modulates PRB transcriptional activity, ChIP-Mass Spectrometry was performed to identify potential cofactors that differentially interact with PRB in the presence of the R5020 and MK+R5020. 14-3-3σ was identified as a protein enriched in the MK+R5020 dataset, and it was demonstrated that 14-3-3σ is required for the upregulation in PRB target gene expression following inhibition of Akt. In order to determine the ramifications of MK+R5020 treatment on angiogenesis, in vitro assays were performed and combinatorial MK+R5020 treatment significantly decreased endothelial cell invasion and tube formation more than MK or R5020 treatment alone. Furthermore, we found that combinatorial MK-2206+Progesterone treatments decreased angiogenesis and proliferation in the Pten^d/d conditional mouse model of endometrial cancer. Taken together, these findings suggest that a combinatorial therapeutic approach utilizing Akt inhibitors with progestins may improve the efficacy of progestin therapy for the treatment of endometrial cancer.

Non-coding RNAs in Uterine Development, Function and Disease

The major function of the uterus is to accept and provide a suitable environment for an embryo, ultimately leading the birth of offspring and successful propagation of the species. For this occur, there must be precise coordination of hormonal signalling within both the endometrial and myometrial components of this organ. Non-coding RNAs, specifically, microRNAs (miRNAs) have been shown to be essential for normal uterine development and function. Within this organ, miRNAs are proposed to fine-tune the actions of the female steroid hormones estradiol and progesterone. Not surprising, mis-expression of miRNAs has been documented in diseases of the endometrium and myometrium such as endometriosis and leiomyomas, respectively. In this chapter, I will review the current understanding on the role, regulation and function of non-coding RNAs focusing on miRNAs in both the normal physiology of the endometrium and myometrium as well as in pathologies of these tissues, namely endometriosis and leiomyomas.

Sirtuin 1 promotes the growth and cisplatin resistance of endometrial carcinoma cells: a novel therapeutic target

Sirtuin 1 (SIRT1), originally identified as a longevity gene, is induced by caloric restriction, and regulates various cellular functions including DNA repair, cell survival and metabolism via the deacetylation of target proteins such as histone and p53. These functions are considered to act dualistically as preventing or facilitating cancer. This study aimed to clarify the expression and role of SIRT1 in endometrial carcinoma. Because a high-calorie diet was a well-known risk factor for endometrial carcinoma, we first hypothesized that SIRT1 might be downregulated in normal endometrial glandular cells of obese women. However, no correlation was observed between the expression of SIRT1 and body mass index (BMI). In contrast, regardless of BMI, the immunohistochemical expression of SIRT1 was significantly higher in endometrial carcinoma (108 cases) than in normal endometria (60 cases) (P<0.05), and its overexpression was associated with a shorter survival (P<0.05). Our experiments in vivo revealed that SIRT1 accelerated the proliferation of endometrial carcinoma cell lines (HHUA, HEC151, and HEC1B). SIRT1 overexpression significantly enhanced the resistance for cisplatin and paclitaxel in HHUA cells. Although p53 is an important target protein for SIRT1, the selective SIRT1 inhibitor (EX527) significantly suppressed the proliferation and cisplatin resistance of three endometrial carcinoma cell lines regardless of the p53 mutation status. In addition, SIRT1 overexpression in HHUA cells accelerated tumor growth and cisplatin resistance in nude mice, and EX527 significantly suppressed the growth of tumors of HHUA and HEC1B cells. No adverse effect of EX527 was observed in these mice. In conclusion, SIRT1 is involved in the acquisition of the aggressive behavior associated with endometrial carcinoma, and the SIRT1 inhibitor, EX527, may be a useful agent for the treatment of this malignancy.

Forkhead box J1 expression is upregulated and correlated with prognosis in patients with clear cell renal cell carcinoma

The forkhead box (FOX) family of transcription factors are considered to have a role in tumorigenesis. FOXJ1 is a member of the FOX family; however, its function in human renal cell carcinoma (RCC) has remained to be elucidated. Therefore, the present study evaluated the expression of FOXJ1 in human clear cell RCC and the effect of FOXJ1 on the proliferative ability of RCC cells. The RCC specimens analyzed in the present study were obtained from 286 patients with RCC who underwent nephrectomy. FOXJ1 mRNA expression levels were determined using reverse transcription-quantitative polymerase chain reaction, and FOXJ1 protein expression levels were determined using immunohistochemistry and western blot analysis. To determine the effect of FOXJ1 on the proliferative ability of RCC cells, the expression of FOXJ1 was decreased using small interfering (si)RNA, and a FOXJ1 vector was stably transfected into RCC cell lines. The proliferative ability of RCC cells was then examined using a WST-1 assay and xenograft experiments with BALB/c nude mice, where the association between FOXJ1 expression and patient survival was determined using Kaplan-Meier analysis. FOXJ1 expression was significantly higher in RCC tissues compared with that of healthy renal tissues. Furthermore, FOXJ1 expression was associated with tumor stage, histologic grade and size. In addition, FOXJ1 significantly enhanced the proliferation of RCC cells in vitro and in vivo. The present study identified that FOXJ1 expression was upregulated in RCC and enhanced the proliferative ability of RCC cells. Therefore, FOXJ1 may serve as an independent prognostic marker and a therapeutic target for the treatment of patients with RCC.

FOXO1 downregulation contributes to the oncogenic program of primary mediastinal B-cell lymphoma

Recently we have shown that the transcription factor FOXO1, highly expressed in B cells, is downregulated in classical Hodgkin lymphoma (cHL). As primary mediastinal B cell lymphoma (PMBL) has similarities with the cHL transcription program we investigated FOXO1 expression in this entity. By using immunohistochemistry we found that FOXO1 was absent or expressed at low levels in 19 of 20 primary PMBL cases. PMBL cell lines reproduce the low FOXO1 expression observed in primary cases. By analyzing gene expression profiling data we found that FOXO1 expression inversely correlated with JAK2 in PMBL cases. Targeting JAK2 activity by the small molecular weight inhibitor TG101348 resulted in upregulation of FOXO1 mRNA and protein expression in MedB-1 and U2940 cell lines, and the MYC inhibitor 10058-F4 increased FOXO1 mRNA in MedB-1 cells. Moreover, in MedB-1 cells FOXO1 expression was strongly upregulated by the inhibitor of DNA methylation 5-aza-2-deoxycytidine and by the histone deacetylase inhibitor trichostatin A. Since FOXO1 promoter was unmethylated, this effect is most likely indirect. FOXO1 activation in the FOXO1-negative MedB-1 cell line led to growth arrest and apoptosis, which was accompanied by repression of MYC and BCL2L1/BCLx_L. Thus, FOXO1 repression might contribute to the oncogenic program and phenotype of PMBL.

The role of microRNAs in the pathogenesis of endometrial cancer: a systematic review

INTRODUCTION

Epigenetics seem to play a primary role in the current research on the pathogenesis of different types of endometrial cancer. Data so far indicate that microRNAs regulate different pathways that could lead to carcinogenesis when not functioning properly. The aim of this review is to summarize current knowledge on microRNAs that have been associated with endometrial cancer development.

MATERIAL AND METHODS

From July 2014 to August 2014, we conducted a comprehensive research utilizing major online search engines (Pubmed, Crossref, Google Scholar). The main keywords used in our search were endometrial cancer/carcinoma; microRNA; epigenetics; novel biomarkers; pathogenesis.

RESULTS

Overall, we identified 155 studies, although only 77 were eligible for this review. Different miRNAs were identified to contribute either promoting the carcinogenesis in the endometrium or inhibiting different steps of endometrial cancer development. Tumour growth, cell proliferation, apoptosis and invasion metastasis have been identified as the main processes where miRNAs seem to be implicated.

CONCLUSIONS

microRNAs are effective regulators of gene expression that has a significant role in the pathogenesis of endometrial cancer. Research concerning possible therapeutic implications has been promising, although there is still a significant distance to be covered between research observations and clinical results. Extensive preclinical and translational research is still required to improve the efficacy and minimize unwanted effects of miRNAs-based therapy.

Activated mutant p110α causes endometrial carcinoma in the setting of biallelic Pten deletion

PTEN and PIK3CA mutations occur with high frequency in uterine endometrioid carcinoma (UEC). Although PTEN mutations are present in complex atypical hyperplasia and carcinoma, PIK3CA mutations are restricted to carcinoma. We generated mouse models harboring Pten loss and/or activated Pik3ca in the endometrial epithelium to investigate their respective roles in the pathogenesis of UEC. Presence of an activated mutant Pik3ca on the background of Pten loss led to aggressive disease, with 100% of mice exhibiting carcinoma. Expression of Pik3ca with E545K mutation alone was unable to cause hyperplasia or cancer in the uterus and did not activate Akt as effectively as Pten deletion in short-term cultures of mouse endometrial epithelium, likely explaining the lack of phenotype in vivo. We also report that nuclear localization of FOXO1 correlated with PTEN mutational status irrespective of the PIK3CA status in endometrial cancer cell lines. Furthermore, gene expression profiles resulting from Pten loss or activation of Pik3ca in primary mouse endometrial epithelial cells exhibit minimal overlap. Thus, Pten and Pik3ca have distinct consequences on the activation of the phosphatidylinositol 3-kinase pathway in endometrial epithelium and are likely to affect other nonoverlapping cellular mechanisms involved in the development and progression of the most common type of uterine cancer.

Role of nuclear progesterone receptor isoforms in uterine pathophysiology

BACKGROUND

Progesterone is a key hormonal regulator of the female reproductive system. It plays a major role to prepare the uterus for implantation and in the establishment and maintenance of pregnancy. Actions of progesterone on the uterine tissues (endometrium, myometrium and cervix) are mediated by the combined effects of two progesterone receptor (PR) isoforms, designated PR-A and PR-B. Both receptors function primarily as ligand-activated transcription factors. Progesterone action on the uterine tissues is qualitatively and quantitatively determined by the relative levels and transcriptional activities of PR-A and PR-B. The transcriptional activity of the PR isoforms is affected by specific transcriptional coregulators and by PR post-translational modifications that affect gene promoter targeting. In this context, appropriate temporal and cell-specific expression and function of PR-A and PR-B are critical for normal uterine function.

METHODS

Relevant studies describing the role of PRs in uterine physiology and pathology (endometriosis, uterine leiomyoma, endometrial cancer, cervical cancer and recurrent pregnancy loss) were comprehensively searched using PubMed, Cochrane Library, Web of Science, and Google Scholar and critically reviewed.

RESULTS

Progesterone, acting through PR-A and PR-B, regulates the development and function of the endometrium and induces changes in cells essential for implantation and the establishment and maintenance of pregnancy. During pregnancy, progesterone via the PRs promotes myometrial relaxation and cervical closure. Withdrawal of PR-mediated progesterone signaling triggers menstruation and parturition. PR-mediated progesterone signaling is anti-mitogenic in endometrial epithelial cells, and as such, mitigates the tropic effects of estrogen on eutopic normal endometrium, and on ectopic implants in endometriosis. Similarly, ligand-activated PRs function as tumor suppressors in endometrial cancer cells through inhibition of key cellular signaling pathways required for growth. In contrast, progesterone via PR activation appears to increase leiomyoma growth. The exact role of PRs in cervical cancer is unclear. PRs regulate implantation and therefore aberrant PR function may be implicated in recurrent pregnancy loss (RPL). PRs likely regulate key immunogenic factors involved in RPL. However, the exact role of PRs in the pathophysiology of RPL and the use of progesterone for therapeutic benefit remains uncertain.

CONCLUSIONS

PRs are key mediators of progesterone action in uterine tissues and are essential for normal uterine function. Aberrant PR function (due to abnormal expression and/or function) is a major cause of uterine pathophysiology. Further investigation of the underlying mechanisms of PR isoform action in the uterus is required, as this knowledge will afford the opportunity to create progestin/PR-based therapeutics to treat various uterine pathologies.

Chitosan Degradation Products Promote Nerve Regeneration by Stimulating Schwann Cell Proliferation via miR-27a/FOXO1 Axis

Natural polysaccharides are biomaterials widely used for constructing scaffolds in tissue engineering. While natural polysaccharides have been shown to robustly promote tissue regeneration, the underlying molecular mechanism remains largely unknown. Here, we show that chitooligosaccharides (COS), the intermediate products of chitosan degradation, stimulate peripheral nerve regeneration in rats. Our experiment also shows that COS stimulate the proliferation of Schwann cells (SCs) during nerve regeneration. By analyzing the transcriptome and gene regulatory network, we identified the miR-27a/FOXO1 axis as the main signaling pathway for mediating the proliferative effects of COS on SCs. COS increase the expression level of miR-27a and cause a reduction of FOXO1, which subsequently accelerates the cell cycle and stimulates SC proliferation to stimulate nerve regeneration. These findings define a basic pathway for oligosaccharides-mediated cell proliferation and reveal a novel aspect of polysaccharide biomaterials in tissue engineering.

Down Regulation of FOXO1 Promotes Cell Proliferation in Cervical Cancer

The Forkhead transcription factor FOXO1, an important downstream target of phosphatidylinositol-3-kinase (PI3K)/AKT signaling pathway, regulates cellular homeostasis by maintaining cell proliferation, apoptosis and viability in normal cells. Though, the function and regulation of FOXO1 is well documented in many cancers, the molecular mechanism of its regulation in cervical cancer is largely unknown. In the present study we have investigated the role of PI3K inhibition on FOXO1 regulation. Expression profiling of primary tumors and cell lines show over expression of PIK3CA and AKT1; and down regulation of FOXO1. Lack of FOXO1 promoter methylation and inability of hypomethylating drug 5-Aza-2'-deoxycytidine and HDAC inhibitor trichostatin A to reactivate FOXO1 expression suggest that loss of FOXO1 expression is due to mechanisms other than promoter methylation/acetylation. Inhibition of PI3K by LY294002 decreased the level of p-AKT1 and activated FOXO1 transcription factor. We demonstrate that activation of FOXO1 induces apoptosis, cell proliferation arrest, and decreased cell viability in cervical cancer cell lines. Our data suggest that frequent down regulation of FOXO1 and its functional inactivation may be due to post-translational modifications in cervical cancer. Together, these observations suggest that activation of FOXO1 and its nuclear sequestration is critical in the regulation of cell proliferation, cell viability and apoptosis in cervical cancer. Hence, PI3K/AKT pathway may be a potential molecular target for cervical cancer therapy.

Influence of AKT on progesterone action in endometrial diseases

Progesterone plays an essential role in the maintenance of the endometrium; it prepares the endometrium for pregnancy, promotes decidualization, and inhibits estrogen-dependent proliferation. Progesterone function is often dysregulated in endometrial disease states. In addition, the PI3K/AKT signaling pathway is often overactive in endometrial pathologies and promotes the survival and proliferation of the diseased cells. Understanding how AKT influences progesterone action is critical in improving hormone-based therapies in endometrial pathologies. Here, we summarize recent studies investigating the crosstalk between the AKT pathway and progesterone receptor function in endometriosis and endometrial cancer.

The FOXO1-miR27 tandem regulates myometrial invasion in endometrioid endometrial adenocarcinoma

Micro-RNA (miRNA) signatures influence the prognosis of cancer, but little is known about their role in myometrial invasion in endometrioid endometrial adenocarcinoma (EEC). We studied miRNA expression signatures in noninvasive and invasive EEC focusing on the alteration of miR-27 and its main target, FOXO1 as well as their relationship with the clinicopathological parameters and other genetic alterations such as PIK3CA mutations. In 25 tumors and 5 normal endometria, unsupervised hierarchical clustering analysis showed that normal endometria and noninvasive EEC were grouped together and separately from invasive and advanced stage tumors. Of the 20 miRNAs differentially expressed in noninvasive (stage IA) and myoinvasive adenocarcinomas (stage IB and IC), miR27 was overexpressed in invasive adenocarcinomas, and its expression increased linearly according to stage. Results were validated by quantitative real-time reverse transcription polymerase chain reaction in an independent series of 44 EEC. By in situ hybridization, miR-27 expression was limited to the stroma. Using quantitative real-time reverse transcription polymerase chain reaction, the expression of proapoptotic transcription factor FOXO1 was down-regulated in invasive compared with noninvasive tumors. Furthermore, we found that the expression of active caspase 3 was higher in noninvasive than invasive EEC. When stratified by PIK3CA mutations, all invasive tumors down-regulated FOXO1, but only nonmutated adenocarcinomas showed miR-27 overexpression. In conclusion, we propose that the miR27-FOXO1 tandem inhibits apoptosis and represents an alternative pathway for tumor cell survival in PIK3CA-nonmutated EEC.

High cytoplasmic FOXO1 and pFOXO1 expression in astrocytomas are associated with worse surgical outcome

FOXO1 is at a convergence point of receptor tyrosine kinase (RTK) signaling, which is one of the three core pathways implicated in glioblastoma. It was recently shown that FOXO1 can effectively induce glioma cell death and inhibit tumor growth through cell cycle arrest and apoptosis. We therefore evaluated FOXO1 and pFOXO1 protein expression in 181 primary astrocytoma samples and 16 normal brain samples. Astrocytoma samples expressed higher cytoplasmic FOXO1 and pFOXO1 than normal brain samples. Nuclear pFOXO1 level was significantly higher than nuclear FOXO1 in astrocytomas. High cytoplasmic FOXO1 expression was associated with older onset age (P = 0.001) and higher WHO grade (P = 0.001). The trend was also observed between cytoplasmic pFOXO1 expression and WHO grade although not significant. Univariate survival analysis showed that both high cytoplasmic FOXO1 and pFOXO1 expression indicated a significantly shorter median overall survival and progression-free survival. Multivariate survival analysis revealed cytoplasmic FOXO1 expression, cytoplasmic pFOXO1 expression, WHO grade, gender, extent of resection and radiotherapy to be independent prognostic factors for overall survival and progression-free survival. Thus, our data suggested that cytoplasmic FOXO1 and pFOXO1 expression may serve as valuable prognostic variables in astrocytomas and may have significant implications for the development and application of targeted therapy.