Endometrial miR-181a and miR-98 expression is altered during transition from normal into cancerous state and target PGR, PGRMC1, CYP19A1, DDX3X, and TIMP3

MicroRNA-98: the multifaceted regulator in human cancer progression and therapy

MicroRNA-98 (miR-98) stands as an important molecule in the intricate landscape of oncology. As a subset of microRNAs, these small non-coding RNAs have accompanied a new era in cancer research, underpinning their significant roles in tumorigenesis, metastasis, and therapeutic interventions. This review provides a comprehensive insight into the biogenesis, molecular properties, and physiological undertakings of miR-98, highlighting its double-edged role in cancer progression-acting both as a tumor promoter and suppressor. Intriguingly, miR-98 has profound implications for various aspects of cancer progression, modulating key cellular functions, including proliferation, apoptosis, and the cell cycle. Given its expression patterns, the potential of miR-98 as a diagnostic and prognostic biomarker, especially in liquid biopsies and tumor tissues, is explored, emphasizing the hurdles in translating these findings clinically. The review concludes by evaluating therapeutic avenues to modulate miR-98 expression, addressing the challenges in therapy resistance, and assessing the efficacy of miR-98 interventions. In conclusion, while miR-98's involvement in cancer showcases promising diagnostic and therapeutic avenues, future research should pivot towards understanding its role in tumor-stroma interactions, immune modulation, and metabolic regulation, thereby unlocking novel strategies for cancer management.

Pleiotropy of Progesterone Receptor Membrane Component 1 in Modulation of Cytochrome P450 Activity

Progesterone receptor membrane component 1 (PGRMC1) is one of few proteins that have been recently described as direct modulators of the activity of human cytochrome P450 enzymes (CYP)s. These enzymes form a superfamily of membrane-bound hemoproteins that metabolize a wide variety of physiological, dietary, environmental, and pharmacological compounds. Modulation of CYP activity impacts the detoxification of xenobiotics as well as endogenous pathways such as steroid and fatty acid metabolism, thus playing a central role in homeostasis. This review is focused on nine main topics that include the most relevant aspects of past and current PGRMC1 research, focusing on its role in CYP-mediated drug metabolism. Firstly, a general overview of the main aspects of xenobiotic metabolism is presented (I), followed by an overview of the role of the CYP enzymatic complex (IIa), a section on human disorders associated with defects in CYP enzyme complex activity (IIb), and a brief account of cytochrome b5 (cyt b5)'s effect on CYP activity (IIc). Subsequently, we present a background overview of the history of the molecular characterization of PGRMC1 (III), regarding its structure, expression, and intracellular location (IIIa), and its heme-binding capability and dimerization (IIIb). The next section reflects the different effects PGRMC1 may have on CYP activity (IV), presenting a description of studies on the direct effects on CYP activity (IVa), and a summary of pathways in which PGRMC1's involvement may indirectly affect CYP activity (IVb). The last section of the review is focused on the current challenges of research on the effect of PGRMC1 on CYP activity (V), presenting some future perspectives of research in the field (VI).

Brain-derived neuerotrophic factor and related mechanisms that mediate and influence progesterone-induced neuroprotection

Historically, progesterone has been studied significantly within the context of reproductive biology. However, there is now an abundance of evidence for its role in regions of the central nervous system (CNS) associated with such non-reproductive functions that include cognition and affect. Here, we describe mechanisms of progesterone action that support its brain-protective effects, and focus particularly on the role of neurotrophins (such as brain-derived neurotrophic factor, BDNF), the receptors that are critical for their regulation, and the role of certain microRNA in influencing the brain-protective effects of progesterone. In addition, we describe evidence to support the particular importance of glia in mediating the neuroprotective effects of progesterone. Through this review of these mechanisms and our own prior published work, we offer insight into why the effects of a progestin on brain protection may be dependent on the type of progestin (e.g., progesterone versus the synthetic, medroxyprogesterone acetate) used, and age, and as such, we offer insight into the future clinical implication of progesterone treatment for such disorders that include Alzheimer's disease, stroke, and traumatic brain injury.

TNFα-Induced Altered miRNA Expression Links to NF-κB Signaling Pathway in Endometriosis

Endometriosis is a common gynecological inflammatory disorder characterized by immune system dysregulation, which is involved in lesion initiation and progression. Studies have demonstrated that several cytokines are associated with the evolution of endometriosis, including tumor necrosis factor-α (TNFα). TNFα is a non-glycosylated cytokine protein with potent inflammatory, cytotoxic, and angiogenic potential. In the current study, we examined the ability of TNFα to induce dysregulation of microRNAs (miRNAs) linked to NFkB signaling pathways, thus contributing to the pathogenesis of endometriosis. Using RT-qPCR, the expression of several miRNAs was quantified in primary cells derived from eutopic endometrium of endometriosis subjects (EESC) and normal endometrial stromal cells (NESC), and also TNFα-treated NESCs. The phosphorylation of the pro-inflammatory molecule NF-κB and the candidates of the survival pathways PI3K, AKT, and ERK was measured by western blot analysis. The elevated secretion of TNFα in EESCs downregulates the expression level of several miRNAs significantly in EESCs compared to NESCs. Also, treatment of NESCs with exogenous TNFα significantly reduced the expression of miRNAs in a dose-dependent manner to levels similar to EESCs. In addition, TNFα significantly increased the phosphorylation of the PI3K, AKT, ERK, and NF-κB signaling pathways. Notably, treatment with curcumin (CUR, diferuloylmethane), an anti-inflammatory polyphenol, significantly increased the expression of dysregulated miRNAs in EESC in a dose-dependent manner. Our findings demonstrate that TNFα is upregulated in EESCs, which subsequently dysregulates the expression of miRNAs, contributing to the pathophysiology of endometriotic cells. CUR effectively inhibits the expression of TNFα, subsequently altering miRNA levels and suppressing the phosphorylation of AKT, ERK, and NF-κB.

hsa-miR-181-5p inhibits human immunodeficiency virus type 1 replication by downregulating DDX3X expression

BACKGROUND

HIV-1 infection affects expression profiles of microRNA. miR-181 is found negatively correlated with HIV-1 viral load. This study aimed to explain that miR-181 targets DDX3X, a host factor involved in HIV-1 nuclear export, thereby inhibiting HIV-1 replication.

METHODS

To verify our hypothesis, first, the relationship between miR-181 expression, DDX3X expression, and HIV-1 viral load was analyzed. Second, miR-181 mimics were transfected into Jurkat cells infected with wild pNL4-3 strain or H9-IIIB cells with HIV-1 replication-competent for HIV-1 viral protein P24(Gag) detection. Besides the reporter gene plasmid containing the DDX3X mRNA sequence was transfected into 293T cells to demonstrate the targeting of miR-181 to the DDX3X mRNA. Finally, the spliced, unspliced, or incompletely spliced HIV-1 transcripts and HIV-1 Tat, Rev, and Gag mRNA were also detected after miR-181 transfection.

RESULTS

Our result proved that miR-181 significantly reduced the HIV-1 viral protein Gag(P24) level and targeted DDX3X mRNA 3'-UTR, inhibiting the unspliced or incompletely spliced HIV-1 mRNA's nuclear export.

CONCLUSION

Our results confirmed that miR-181 is involved in HIV-1 viral replication in lymphocytes by downregulating DDX3X expression. The research provides a research basis for future HIV-1 antiviral research.

The Role of MicroRNAs in Development of Endometrial Cancer: A Literature Review

Endometrial cancer (EC) ranks as the second most common gynaecological cancer worldwide. EC patients are diagnosed at an early clinical stage and generally have a good prognosis. Therefore, there is a dire need for development of a specific marker for early detection of endometrial adenocarcinoma. The development of EC is conditioned by a multistep process of oncogenic upregulation and tumor suppressor downregulation as shown by molecular genetic evidence. In this setting, microRNAs appear as significant regulators of gene expression and several variations in the expression of microRNAs have been implicated in normal endometrium, endometrial tissue, metrorrhagia, and endometrial cancer. Furthermore, microRNAs act as highly precise, sensitive, and robust molecules, making them potential markers for diagnosing specific cancers and their progression. With the rising incidence of EC, its management remains a vexing challenge and diagnostic methods for the disease are limited to invasive, expensive, and inaccurate tools. Therefore, the prospect of exploiting the utility of microRNAs as potential candidates for diagnosis and therapeutic use in EC seems promising.

TNFα-induced altered miRNA expression links to NF-κB signaling pathway in endometriosis

Endometriosis is a common gynecological inflammatory disorder characterized by immune system dysregulation, which is involved in lesion initiation and progression. Studies have demonstrated that several cytokines are associated with the evolution of endometriosis, including tumor necrosis factor-α (TNFα). TNFα is a non-glycosylated cytokine protein with potent inflammatory, cytotoxic, and angiogenic potential. In the current study, we examined the ability of TNFα to induce dysregulation of microRNAs (miRNAs) linked to NFkB-signaling pathways, thus contributing to the pathogenesis of endometriosis. Using RT-QPCR, the expression of several miRNAs were quantified in primary cells derived from eutopic endometrium of endometriosis subjects (EESC) and normal endometrial stromal cells (NESC) and also TNFα treated NESCs. The phosphorylation of the pro-inflammatory molecule NF-κB and the candidates of the survival pathways PI3K, AKT and ERK was measured by westernblot analysis. The elevated secretion of TNFα in EESCs downregulates the expression level of several miRNAs significantly (p < 0.05) in EESCs compared to NESC. Also treatment of NESCs with exogenous TNFα significantly reduced the expression of miRNAs in a dose-dependent manner to levels similar to EESCs. In addition, TNFα significantly increased the phosphorylation of the PI3K, AKT, ERK, and NF-κB signaling pathways. Notably, treatment with curcumin (CUR, diferuloylmethane), an anti-inflammatory polyphenol, significantly increased the expression of dysregulated miRNAs in EESC in a dose-dependent manner. Our findings demonstrate that TNFα is upregulated in EESCs, which subsequently dysregulates the expression of miRNAs, contributing to the pathophysiology of endometriotic cells. CUR effectively inhibits the expression of TNFα, subsequently altering miRNA levels and suppresses the phosphorylation of AKT, ERK, and NF-κB.

Regulation of progesterone receptor expression in endometriosis, endometrial cancer, and breast cancer by estrogen, polymorphisms, transcription factors, epigenetic alterations, and ubiquitin-proteasome system

The uterus and breasts are hormone-responsive tissues. Progesterone and estradiol regulate gonadotropin secretion, prepare the endometrium for implantation, maintain pregnancy, and regulate the differentiation of breast tissue. Dysregulation of these hormones causes endometriosis, endometrial cancer, and breast cancer, damaging the physical and mental health of women. Emerging evidence has shown that progesterone resistance or elevated progesterone activity is the primary hormonal substrate of these diseases. Since progesterone acts through its specific nuclear receptor, the abnormal expression of the progesterone receptor (PR) dysregulates progesterone function. This review discusses the regulatory mechanisms of PR expression in patients with endometriosis, and endometrial or breast cancer, including estrogen, polymorphisms, transcription factors, epigenetics, and the ubiquitin-proteasome system. (1) Estrogen promotes the expression of PRA (a PR isoform) mRNA and protein through the interaction of estrogen receptors (ERs) and Sp1 with half-ERE/Sp1 binding sites. ERs also affect the binding of Sp1 and Sp1 sites to promote the expression of PRB (another PR isoform)(2) PR polymorphisms, mainly PROGINS and + 331 G/A polymorphism, regulate PR expression by affecting DNA methylation and transcription factor binding. (3) The influence of epigenetic alterations on PR expression occurs through DNA methylation, histone modification, and microRNA. (4) As one of the main protein degradation pathways in vivo, the ubiquitin-proteasome system (UPS) regulates PR expression by participating in protein degradation. These mechanisms may provide new molecular targets for diagnosing and treating endometriosis, endometrial, and breast cancer.

The role of progesterone receptor membrane component (PGRMC) in the endometrium

PGRMC is a non-classical receptor that mediates the non-genomic responses to progesterone and is distributed in different subcellular compartments. PGRMC belongs to the membrane-associated progesterone receptor (MAPR) family. Two PGRMC subtypes (PGRMC1 and PGRMC2) have been characterized, and both are expressed in the human endometrium. PGRMC expression is differentially regulated during the menstrual cycle in the human endometrium. Although PGRMC1 is predominantly expressed in the proliferative phase and PGRMC2 in the secretory phase, this expression changes in pathologies such as endometriosis, in which PGRMC2 expression considerably decreases, promoting progesterone resistance. In endometrial cancer, PGRMC1 is overexpressed, its activation induces tumors growth, and confers chemoresistance in the presence of progesterone. Thus, PGRMCs play a key role in progesterone actions in the endometrium.

Pleiotropic Actions of PGRMC Proteins in Cancer

Progesterone receptor membrane component (PGRMC) proteins play important roles in tumor growth, progression, and chemoresistance, of which PGRMC1 is the best characterized. The ancestral member predates the evolution of metazoans, so it is perhaps not surprising that many of the purported actions of PGRMC proteins are rooted in fundamental metabolic processes such as proliferation, apoptosis, and DNA damage responses. Despite mediating some of the actions of progesterone (P4) and being fundamentally required for female fertility, PGRMC1 and PGRMC2 are broadly expressed in most tissues. As such, these proteins likely have both progesterone-dependent and progesterone-independent functions. It has been proposed that PGRMC1 acquired the ability to mediate P4 actions over evolutionary time through acquisition of its cytochrome b5-like heme/sterol-binding domain. Diverse reproductive and nonreproductive diseases associate with altered PGRMC1 expression, epigenetic regulation, or gene silencing mechanisms, some of which include polycystic ovarian disease, premature ovarian insufficiency, endometriosis, Alzheimer disease, and cancer. Although many studies have been completed using transformed cell lines in culture or in xenograft tumor approaches, recently developed transgenic model organisms are offering new insights in the physiological actions of PGRMC proteins, as well as pathophysiological and oncogenic consequences when PGRMC expression is altered. The purpose of this mini-review is to provide an overview of PGRMC proteins in cancer and to offer discussion of where this field must go to solidify PGRMC proteins as central contributors to the oncogenic process.

Possible Involvement of miR-98 in the Regulation of PGRMC1 During Decidualization

Human endometrial stromal cells (ESCs) differentiate into decidual cells for embryo implantation during the mid-secretory phase of the menstrual cycle. Decidualization is characterized by enhanced production of insulin-like growth factor-binding protein 1 (IGFBP1) and prolactin (PRL) by ESCs and their morphological transformation into polygonal cells. Progesterone (P4) receptor membrane component 1 (PGRMC1) is a member of a P4-binding complex implicated in function in female reproduction. In this study, we explored the mechanisms that regulate PGRMC1 during decidualization of human ESCs. Immunohistochemical analysis of endometrial samples showed that PGRMC1 was expressed in endometrial glandular and luminal epithelial cells and stromal cells throughout the menstrual cycle; however, the protein level in stroma was reduced in the secretory phase. Incubation of ESCs with dibutyryl (db)-cAMP and P4 in vitro, which induces decidualization, decreased the PGRMC1 protein abundance. Further, treatment with a PGRMC1-targeting siRNA or PGRMC1 inhibitor (AG-205) promoted mRNA expression of the db-cAMP/P4- and db-cAMP-induced decidual markers IGFBP1 and PRL. Moreover, the microRNA miR-98, a potential repressor of PGRMC1, was upregulated during decidualization, and transfection of ESCs with a miR-98 mimic decreased the PGRMC1 protein level. These findings suggest that miR-98-mediated downregulation of endometrial PGRMC1 may promote decidualization for the establishment of pregnancy.

PITPNA-AS1/miR-98-5p to Mediate the Cisplatin Resistance of Gastric Cancer

Gastric cancer (GC) is the most deadly gastrointestinal malignancy with high incidence and mortality. Although, molecular mechanisms which drive gastric cancer progression are extensively investigated, the roles of long noncoding RNA (lncRNA) in gastric cancer growth and drug sensitivity remain unclear. Platinum is a mainstay to treat gastric cancer, and platinum resistance always leads to the local recurrence of gastric cancer. Therefore, it is important to identify biomarkers or therapeutic targets to sensitize gastric cancer to platinum. In this study, we employ noncoding RNA sequencing and found that lncRNA PITPNA-AS1 is overexpressed in gastric cancer tissues and associated with poor survival of gastric cancer patients. Kockdown of PITPNA-AS1 in gastric cancer cells significantly inhibited cell growth and triggered apoptotic cell death in gastric cancer cells. Also, cisplatin treatment could decrease PITPNA-AS1 levels in gastric cancer cells through inhibiting H3K27ac. Besides, PITPNA-AS1 is elevated in cisplatin-resistant gastric cancer cells and tissues, PITPNA-AS1 knockdown could sensitize gastric cancer cells to cisplatin treatment. Furthermore, we identified that PITPNA-AS1 directly interacts and inhibits miR-98-5p. Therefore, PITPNA-AS1 could be served as a potential biomarkers and curative therapeutic targets for gastric cancer progression.

MicroRNAs and Progesterone Receptor Signaling in Endometriosis Pathophysiology

Endometriosis is a significant disease characterized by infertility and pelvic pain in which endometrial stromal and glandular tissue grow in ectopic locations. Altered responsiveness to progesterone is a contributing factor to endometriosis pathophysiology, but the precise mechanisms are poorly understood. Progesterone resistance influences both the eutopic and ectopic (endometriotic lesion) endometrium. An inability of the eutopic endometrium to properly respond to progesterone is believed to contribute to the infertility associated with the disease, while an altered responsiveness of endometriotic lesion tissue may contribute to the survival of the ectopic tissue and associated symptoms. Women with endometriosis express altered levels of several endometrial progesterone target genes which may be due to the abnormal expression and/or function of progesterone receptors and/or chaperone proteins, as well as inflammation, genetics, and epigenetics. MiRNAs are a class of epigenetic modulators proposed to play a role in endometriosis pathophysiology, including the modulation of progesterone signaling. In this paper, we summarize the role of progesterone receptors and progesterone signaling in endometriosis pathophysiology, review miRNAs, which are over-expressed in endometriosis tissues and fluids, and follow this with a discussion on the potential regulation of key progesterone signaling components by these miRNAs, concluding with suggestions for future research endeavors in this area.

A Novel miR-98 Negatively Regulates the Resistance of Endometrial Cancer Cells to Paclitaxel by Suppressing ABCC10/MRP-7

Endometrial cancer (EC) is one of the most frequent gynecological tumors, and chemoresistance is a major obstacle to improving the prognosis of EC patients. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have recently emerged as crucial chemoresistance regulators that alter the levels of downstream target genes. Multidrug Resistance Protein 7 (MRP-7/ABCC10) is an ATP-binding cassette transporter that causes the resistance to anti-cancer drugs. The purpose of this research is to determine whether MRP-7 has a role in mediating the sensitivity of EC cells to paclitaxel and whether the expression of MRP-7 is regulated by miR-98 and lncRNA NEAT1. We reported that the levels of MRP-7 were significantly increased in EC tissues and associated with an unfavorable prognosis. Downregulation of MRP-7 in EC cells sensitized these cells to paclitaxel and reduced cell invasion. PLAUR serves as a downstream molecule of MRP-7 and facilitates paclitaxel resistance and EC cell invasiveness. Moreover, miR-98 serves as a tumor suppressor to inhibit MRP-7 expression, leading to the repression of paclitaxel resistance. Furthermore, a novel lncRNA, NEAT1, was identified as a suppressor of miR-98, and NEAT1 could upregulate MRP-7 levels by reducing the expression of miR-98. Taken together, these findings demonstrate that upregulation of MRP-7 and NEAT1, and downregulation of miR-98 have important roles in conferring paclitaxel resistance to EC cells. The modulation of these molecules may help overcome the chemoresistance against paclitaxel in EC cells.

Progesterone Receptor Membrane Component (PGRMC)1 and PGRMC2 and Their Roles in Ovarian and Endometrial Cancer

Cancers of the female reproductive tract are both lethal and highly prevalent. For example, the five-year survival rate of women diagnosed with ovarian cancer is still less than 50%, and endometrial cancer is the fourth most common cancer in women with > 65,000 new cases in the United States in 2020. Among the many genes already established as key participants in ovarian and endometrial oncogenesis, progesterone receptor membrane component (PGRMC)1 and PGRMC2 have gained recent attention given that there is now solid correlative information supporting a role for at least PGRMC1 in enhancing tumor growth and chemoresistance. The expression of PGRMC1 is significantly increased in both ovarian and endometrial cancers, similar to that reported in other cancer types. Xenograft studies using human ovarian and endometrial cancer cell lines in immunocompromised mice demonstrate that reduced expression of PGRMC1 results in tumors that grow substantially slower. While the molecular underpinnings of PGRMCs' mechanisms of action are not clearly established, it is known that PGRMCs regulate survival pathways that attenuate stress-induced cell death. The objective of this review is to provide an overview of what is known about the roles that PGRMC1 and PGRMC2 play in ovarian and endometrial cancers, particularly as related to the mechanisms through which they regulate mitosis, apoptosis, chemoresistance, and cell migration.

Expression of Estrogen Receptor- and Progesterone Receptor-Regulating MicroRNAs in Breast Cancer

In ~70% of breast cancer (BC) cases, estrogen and progesterone receptors (ER and PR) are overexpressed, which can change during tumor progression. Expression changes of these receptors during cancer initiation and progression can be caused by alterations in microRNA (miR, miRNA) expression. To assess the association of BC progression with aberrant expression of miRNAs that target ER and PR mRNAs, we quantified miR-19b, -222, -22, -378a, and -181a in BC samples (n = 174) by real-time PCR. Underexpression of miR-222 and miR-378a in stage T2–T4 BC was characteristic for HER2-overexpressing tumors. In addition, the expression of miR-181a and miR-378a was higher in these tumors than in tumors with a HER2 IHC score of 0 or 1+. In tumors with a Ki-67 index ≥ 14%, all tested miRNAs were underexpressed in BC with a high Allred PR score (6–8). In ER-and-PR–negative tumors, miR-22, miR-222, miR-181a, and miR-378a underexpression was associated with Ki-67 index > 35% (median value). MiR-19b and miR-22 underexpression could be a marker of lymph node metastasis in ER- and/or PR-positive tumors with HER2 IHC score 0. Thus, the association of miR-19b, miR-22, miR-222, miR-378a, and miR-181a levels with BC characteristics is influenced by the status of tumor ER, PR, HER2, and Ki-67.

MicroRNAs and Long Noncoding RNAs as Novel Therapeutic Targets in Estrogen Receptor-Positive Breast and Ovarian Cancers

Aromatase inhibitors (AIs) such as anastrozole, letrozole, and exemestane have shown to prevent metastasis and angiogenesis in estrogen receptor (ER)-positive breast and ovarian tumors. They function primarily by reducing estrogen production in ER-positive post-menopausal breast and ovarian cancer patients. Unfortunately, current AI-based therapies often have detrimental side-effects, along with acquired resistance, with increased cancer recurrence. Thus, there is an urgent need to identify novel AIs with fewer side effects and improved therapeutic efficacies. In this regard, we and others have recently suggested noncoding RNAs (ncRNAs), specifically microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), as potential molecular targets for utilization in modulating cancer hallmarks and overcoming drug resistance in several cancers, including ER-positive breast and ovarian cancer. Herein, we describe the disruptive functions of several miRNAs and lncRNAs seen in dysregulated cancer metabolism, with a focus on the gene encoding for aromatase (CYP19A1 gene) and estrogen synthesis as a novel therapeutic approach for treating ER-positive breast and ovarian cancers. Furthermore, we discuss the oncogenic and tumor-suppressive roles of several miRNAs (oncogenic miRNAs: MIR125b, MIR155, MIR221/222, MIR128, MIR2052HG, and MIR224; tumor-suppressive miRNAs: Lethal-7f, MIR27B, MIR378, and MIR98) and an oncogenic lncRNA (MIR2052HG) in aromatase-dependent cancers via transcriptional regulation of the CYP19A1 gene. Additionally, we discuss the potential effects of dysregulated miRNAs and lncRNAs on the regulation of critical oncogenic molecules, such as signal transducer, and activator of transcription 3, β-catenin, and integrins. The overall goal of this review is to stimulate further research in this area and to facilitate the development of ncRNA-based approaches for more efficacious treatments of ER-positive breast and ovarian cancer patients, with a slight emphasis on associated treatment–delivery mechanisms.

MicroRNA as Epigenetic Modifiers in Endometrial Cancer: A Systematic Review

Simple Summary

Endometrial cancer (EC) is the 2nd most common gynecologic cancer worldwide. MicroRNAs (miRNAs) are small noncoding RNAs that contribute to epigenetic regulation. The objective of this systematic review is to summarize our current knowledge on the role of miRNAs in the epigenetic deregulation of tumor-related genes in EC. It includes all miRNAs reported to be involved in EC including their roles in DNA methylation and RNA-associated silencing. This systematic review should be useful for development of novel strategies to improve diagnosis and risk assessment as well as for new treatments aimed at miRNAs, their target genes or DNA methylation.

Abstract

The objective of this systematic review is to summarize our current knowledge on the influence of miRNAs in the epigenetic deregulation of tumor-related genes in endometrial cancer (EC). We conducted a literature search on the role of miRNAs in the epigenetic regulation of EC applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following terms were used: microRNA, miRNA, miR, endometrial cancer, endometrium, epigenetic, epimutation, hypermethylation, lynch, deacetylase, DICER, novel biomarker, histone, chromatin. The miRNAs were classified and are presented according to their function (tumor suppressor or onco-miRNA), their targets (when known), their expression levels in EC tissue vs the normal surrounding tissue, and the degree of DNA methylation in miRNA loci and CpG sites. Data were collected from 201 articles, including 190 original articles, published between November 1, 2008 and September 30, 2020 identifying 313 different miRNAs implicated in epigenetic regulation of EC. Overall, we identified a total of 148 miRNAs with decreased expression in EC, 140 miRNAs with increased expression in EC, and 22 miRNAs with discordant expression levels. The literature implicated different epigenetic phenomena including altered miRNA expression levels (miR-182, -230), changes in the methylation of miRNA loci (miR-34b, -129-2, -130a/b, -152, -200b, -625) and increased/decreased methylation of target genes (miR-30d,-191). This work provides an overview of all miRNAs reported to be involved in epigenetic regulation in EC including DNA methylation and RNA-associated silencing. These findings may contribute to novel strategies in diagnosis, risk assessment, and treatments aimed at miRNAs, their target genes or DNA methylation.

microRNA-181 serves as a dual-role regulator in the development of human cancers

MicroRNAs (miRNAs) as the regulatory short noncoding RNAs are involved in a wide array of cellular and molecular processes. They negatively regulate gene expression and their dysfunction is correlated with cancer development through modulation of multiple signaling pathways. Therefore, these molecules could be considered as novel biomarkers and therapeutic targets for more effective management of human cancers. Recent studies have demonstrated that the miR-181 family is dysregulated in various tumor tissues and plays a pivotal role in carcinogenesis. They have been shown to act as oncomirs or tumor suppressors considering their mRNA targets and to be involved in cell proliferation, apoptosis, autophagy, angiogenesis and drug resistance. Additionally, these miRNAs have been demonstrated to exert their regulatory effects through modulating multiple signaling pathways including PI3K/AKT, MAPK, TGF-b, Wnt, NF-κB, Notch pathways. Given that, in this review, we briefly summarise the recent studies that have focused on the roles of miRNA-181 family as the multifunctional miRNAs in tumorigenesis and cancer development. These miRNAs may serve as diagnostic and prognostic biomarkers or therapeutic targets in human cancer gene therapy.

High Mobility Group A (HMGA): Chromatin Nodes Controlled by a Knotty miRNA Network

High mobility group A (HMGA) proteins are oncofoetal chromatin architectural factors that are widely involved in regulating gene expression. These proteins are unique, because they are highly expressed in embryonic and cancer cells, where they play a relevant role in cell proliferation, stemness, and the acquisition of aggressive tumour traits, i.e., motility, invasiveness, and metastatic properties. The HMGA protein expression levels and activities are controlled by a connected set of events at the transcriptional, post-transcriptional, and post-translational levels. In fact, microRNA (miRNA)-mediated RNA stability is the most-studied mechanism of HMGA protein expression modulation. In this review, we contribute to a comprehensive overview of HMGA-targeting miRNAs; we provide detailed information regarding HMGA gene structural organization and a comprehensive evaluation and description of HMGA-targeting miRNAs, while focusing on those that are widely involved in HMGA regulation; and, we aim to offer insights into HMGA-miRNA mutual cross-talk from a functional and cancer-related perspective, highlighting possible clinical implications.

Progesterone Effects in the Nervous System

The sex hormone progesterone is mainly known as a key factor in establishing and maintaining pregnancy. In addition, progesterone has been shown to induce morphological changes in the central and peripheral nervous system by increasing dendrito-, spino-, and synaptogenesis in Purkinje cells (Wessel et al.: Cell Mol Life Sci (2014a) 1723-1740) and increasing axonal outgrowth in dorsal root ganglia (Olbrich et al.: Endocrinology (2013) 3784-3795). These effects mediated mainly by the classical progesterone receptors (PRs) A and B seem to be limited to young neurons. It may be assumed that microRNAs (miRNAs), which are potent regulators of nervous system maturation and degeneration, are also involved in the regulation of progesterone-mediated neuronal plasticity by altering the expression patterns of the corresponding PR A/B receptors (Theis and Theiss: Neural Regen Res (2015) 547-549, Pieczora et al.: Cerebellum (2017) 376-387). This review critically discusses current data on the neuroprotective effect of progesterone and its corresponding receptors in the nervous system, with possible regulatory processes by miRNAs. Preclinical studies on stroke and traumatic brain injury revealed neuroprotective and neuroregenerative effects of progesterone in the treatment of severe neurological diseases in animal models, but have so far failed in humans. In this context, the identification of specific miRNAs that regulate the expression of progesterone and PR could help to exploit the neuroprotective potential of progesterone for the treatment of various neurological disorders. Anat Rec, 302:1276-1286, 2019. © 2019 Wiley Periodicals, Inc.

MicroRNA-98 reduces amyloid β-protein production and improves oxidative stress and mitochondrial dysfunction through the Notch signaling pathway via HEY2 in Alzheimer's disease mice

Alzheimer's disease (AD) is a chronic neurodegenerative disease that often occurs at a slow pace yet deteriorates with time. MicroRNAs (miRs) have been demonstrated to offer novel therapeutic hope for disease treatment. The aim of the present study was to investigate the effect of miR‑98 on amyloid β (Aβ)‑protein production, oxidative stress and mitochondrial dysfunction through the Notch signaling pathway by targeting hairy and enhancer of split (Hes)‑related with YRPW motif protein 2 (HEY2) in mice with AD. A total of 70 Kunming mice were obtained and subjected to behavioral assessment. The levels of oxidative stress‑related proteins glutathione peroxidase, reduced glutathione, superoxide dismutase, malondialdehyde, acetylcholinesterase and Na+‑K+‑ATP were measured. Morphological changes in brain tissue, HEY2‑positivity levels, neuronal apoptotic index (AI) and neuron mitochondrial DNA (mtDNA) levels were also determined. Subsequently, the levels of miR‑98 and the mRNA and protein levels of HEY2, Jagged1, Notch1, Hes1, Hes5, β‑amyloid precursor protein, B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X protein in tissues and hippocampal neurons were determined by reverse transcription‑quantitative polymerase chain reaction and western blot analyses, respectively. Finally, hippocampal neuron viability and apoptosis were determined using an MTT assay and flow cytometry, respectively. The levels of miR‑98‑targeted HEY2 and miR‑98 were low and the levels of HEY2 were high in the AD mice. The AD mice exhibited poorer learning and memory abilities, oxidative stress function, and morphological changes of pyramidal cells in the hippocampal CA1 region. Furthermore, the AD mice exhibited increased protein levels of HEY2 and AI in the CA1 region of brain tissues with reduced mtDNA levels and dysfunctional neuronal mitochondria. miR‑98 suppressed hippocampal neuron apoptosis and promoted hippocampal neuron viability by inactivating the Notch signaling pathway via the inhibition of HEY2. In conclusion, the results demonstrated that miR‑98 reduced the production of Aβ and improved oxidative stress and mitochondrial dysfunction through activation of the Notch signaling pathway by binding to HEY2 in AD mice.

The transcription factor SMAD4 and miR-10b contribute to E2 release and cell apoptosis in ovarian granulosa cells by targeting CYP19A1

The cytochrome P450 family 19 subfamily A member 1 (CYP19A1) gene, encodes aromatase, a key enzyme in estradiol (E2) synthesis, and is down-regulated during porcine follicular atresia. However, its role in and the mechanism of transcriptional repression in follicular atresia is largely unknown. In the present study, we show that the CYP19A1 gene stimulates E2 release and inhibits cell apoptosis in porcine granulosa cells (GCs). SMAD4, an anti-apoptotic moderator, was identified as a transcription factor of the porcine CYP19A1 gene and enhanced the expression and function of CYP19A1 in porcine GCs through direct binding to a SMAD4-binding element (SBE) within the promoter region of CYP19A1 gene. Moreover, we found that miR-10b, a pro-apoptotic factor, directly interacted with 3'-UTR of the porcine CYP19A1 mRNA, inhibiting its expression and function in porcine GCs. Collectively, we demonstrated that CYP19A1 is an inhibitor of follicular atresia and is regulated by both SMAD4 and miR-10b. These findings provide further insight into the mechanisms of CYP19A1 in steroid hormone synthesis and GC apoptosis and provide molecular targets for exploring methods of treatment for steroid-dependent reproductive disorders.

Mouse double minute homologue 2 (MDM2) downregulation by miR-661 impairs human endometrial epithelial cell adhesive capacity

Human blastocysts that fail to implant following IVF secrete elevated levels of miR-661, which is taken up by primary human endometrial epithelial cells (HEECs) and impairs their adhesive capability. MicroRNA miR-661 downregulates mouse double minute homologue 2 (MDM2) and MDM4 in other epithelial cell types to activate p53; however, this has not been examined in the endometrium. In this study MDM2 protein was detected in the luminal epithelium of the endometrium, the site of blastocyst attachment, during the mid secretory receptive phase of the menstrual cycle. The effects of miR-661 on gene expression in and adhesion of endometrial cells was also examined. MiR-661 overexpression consistently downregulated MDM2 but not MDM4 or p53 gene expression in the Ishikawa endometrial epithelial cell line and primary HEEC. Adhesion assays were performed on the real-time monitoring xCELLigence system and by co-culture using Ishikawa cells and HEECs with HTR8/SVneo trophoblast spheroids. Targeted siRNA-mediated knockdown of MDM2 in endometrial epithelial cells reduced Ishikawa cell adhesion (P<0.001) and also reduced HTR8/SVneo trophoblast spheroid adhesion to Ishikawa cells (P<0.05) and HEECs (P<0.05). MDM2 overexpression using recombinant protein treatment resulted in enhanced HTR8/SVneo trophoblast spheroid adhesion to Ishikawa cells (P<0.01) and HEECs (P<0.05). This study highlights a potential new mechanism by which human blastocyst-secreted miR-661 reduces endometrial epithelial cell adhesion; via downregulation of MDM2. These findings suggest that MDM2 contributes to endometrial-blastocyst adhesion, implantation and infertility in women.

miR-98-5p contributes to cisplatin resistance in epithelial ovarian cancer by suppressing miR-152 biogenesis via targeting Dicer1

Epithelial ovarian cancer (EOC) is a highly lethal gynecological malignancy, and cisplatin resistance is usually correlated with the poor prognosis of EOC. Increasing evidence indicates that the dysregulation of miRNAs is related to chemotherapy sensitivity. In this study, we revealed that miR-98-5p, a member of the let-7 family, was enriched in cisplatin-resistant EOC cells compared with cisplatin-sensitive cells, and could promote cisplatin resistance in EOC cells. Further studies showed that miR-98-5p could directly target the 3′-UTR of Dicer1 and suppress its expression, causing global miRNA downregulation. By miRNA array and qRT-PCR verification, we identified miR-152 as the vital downstream target of the miR-98-5p/Dicer1 axis in EOC cells. Moreover, we demonstrated that the ectopic expression of miR-152 reversed cisplatin resistance both in vitro and in vivo by targeting RAD51, a central member in homologous recombination. Importantly, miR-98-5p expression, as determined by in situ hybridization in tumor tissues, was associated with poor outcome of EOC patients. Together, these findings suggest the essential role of the miR-98-5p/Dicer1/miR-152 pathway in regulating cisplatin resistance of EOC cells and provide a potential target for EOC therapy.

Progesterone receptor membrane component 1 as a potential prognostic biomarker for hepatocellular carcinoma

AIM

To investigate the clinicopathological significance of progesterone receptor membrane component 1 (PGRMC1) and PGRMC2 in hepatocellular carcinoma (HCC).

METHODS

We performed immunohistochemical staining to evaluate the estrogen receptor (ER), progesterone receptor (PR), PGRMC1, and PGRMC2 in a clinical cohort consisting of 89 paired HCC and non-tumor liver samples. We also analyzed HCC data (n = 373) from The Cancer Genome Atlas (TCGA). We correlated the expression status of PGRMC1 and PGRMC2 with clinicopathological indicators and the clinical outcomes of the HCC patients. We knocked down or overexpressed PGRMC1 in HCC cell lines to evaluate its biological significance in HCC cell proliferation, differentiation, migration, and invasion.

RESULTS

We found that few HCC cases expressed ER (5.6%) and PR (4.5%). In contrast, most HCC cases expressed PGRMC1 (89.9%) and PGRMC2 (100%). PGRMC1 and PGRMC2 exhibited significantly lower expression in tumor tissue than in non-tumor tissue (P < 0.001). Lower PGRMC1 expression in HCC was significantly associated with higher serum alpha-fetoprotein expression (P = 0.004), poorer tumor differentiation (P = 0.045) and liver capsule penetration (P = 0.038). Low PGRMC1 expression was an independent predictor for worse disease-free survival (P = 0.002, HR = 2.384, CI: 1.377-4.128) in our cases, as well as in the TCGA cohort (P < 0.001, HR = 2.857, CI: 1.781-4.584). The expression of PGRMC2 did not relate to patient outcome. PGRMC1 knockdown promoted a poorly differentiated phenotype and proliferation of HCC cells in vitro, while PGRMC1 overexpression caused the opposite effects.

CONCLUSION

PGRMC1 is a non-classical hormonal receptor that negatively regulates hepatocarcinogenesis. PGRMC1 down-regulation is associated with progression of HCC and is a poor prognostic indicator.

MicroRNA regulation of progesterone receptor in breast cancer

Hormone receptor status is of significant value when deciding on anti-estrogenic adjuvant therapy for breast cancer tumors. However, while estrogen receptor (ER) regulation was intensively studied, the regulation of progesterone receptor (PR) levels has not been extensively investigated. MicroRNAs (miRNAs, miRs) are post-transcriptional negative regulators of gene expression involved in diverse cellular processes. The aim of this study was to identify miRNAs that regulate PR in breast cancer.We mapped potential miRNA binding sites for miR-181a, miR-23a and miR-26b on PR mRNA and demonstrated a direct regulation of PR by these three miRNAs by in-vitro Luciferase binding assays. Over-expression of each miRNA in MCF-7 cells resulted in a reduction in the expression levels of PR mRNA. Then, expression levels of these miRNAs were measured in Formalin-Fixed, Paraffin-Embedded (FFPE) samples of 29 ER-positive breast cancer tumors and adjacent normal breast tissues. A significant reciprocal correlation between PR mRNA and the miRNA levels were identified suggesting a role for miR-181a, miR-23a and miR-26b in PR regulation in breast cancer. Moreover, the average expression fold-changes of the three miRNAs between cancerous and normal tissues displayed an opposite trend when analyzing according to Immuno-histochemistry(IHC) status. Furthermore, miR-181a and miR-26b were found to be over-expressed in most tumor tissues supporting their role in ER-positive breast cancer development. We conclude that miR-181a, miR-23a and miR-26b act as negative regulators of PR expression in ER-positive breast cancer. The diagnostic and prognostic potential of these miRNAs in breast cancer should be further evaluated.

Dynamic and Modularized MicroRNA Regulation and Its Implication in Human Cancers

MicroRNA is responsible for the fine-tuning of fundamental cellular activities and human disease development. The altered availability of microRNAs, target mRNAs, and other types of endogenous RNAs competing for microRNA interactions reflects the dynamic and conditional property of microRNA-mediated gene regulation that remains under-investigated. Here we propose a new integrative method to study this dynamic process by considering both competing and cooperative mechanisms and identifying functional modules where different microRNAs co-regulate the same functional process. Specifically, a new pipeline was built based on a meta-Lasso regression model and the proof-of-concept study was performed using a large-scale genomic dataset from ~4,200 patients with 9 cancer types. In the analysis, 10,726 microRNA-mRNA interactions were identified to be associated with a specific stage and/or type of cancer, which demonstrated the dynamic and conditional miRNA regulation during cancer progression. On the other hands, we detected 4,134 regulatory modules that exhibit high fidelity of microRNA function through selective microRNA-mRNA binding and modulation. For example, miR-18a-3p, -320a, -193b-3p, and -92b-3p co-regulate the glycolysis/gluconeogenesis and focal adhesion in cancers of kidney, liver, lung, and uterus. Furthermore, several new insights into dynamic microRNA regulation in cancers have been discovered in this study.

Genome-wide analysis of brain and gonad transcripts reveals changes of key sex reversal-related genes expression and signaling pathways in three stages of Monopterus albus

Background

The natural sex reversal severely affects the sex ratio and thus decreases the productivity of the rice field eel (Monopterus albus). How to understand and manipulate this process is one of the major issues for the rice field eel stocking. So far the genomics and transcriptomics data available for this species are still scarce. Here we provide a comprehensive study of transcriptomes of brain and gonad tissue in three sex stages (female, intersex and male) from the rice field eel to investigate changes in transcriptional level during the sex reversal process.

Results

Approximately 195 thousand unigenes were generated and over 44.4 thousand were functionally annotated. Comparative study between stages provided multiple differentially expressed genes in brain and gonad tissue. Overall 4668 genes were found to be of unequal abundance between gonad tissues, far more than that of the brain tissues (59 genes). These genes were enriched in several different signaling pathways. A number of 231 genes were found with different levels in gonad in each stage, with several reproduction-related genes included. A total of 19 candidate genes that could be most related to sex reversal were screened out, part of these genes’ expression patterns were validated by RT-qPCR. The expression of spef2, maats1, spag6 and dmc1 were abundant in testis, but was barely detected in females, while the 17β-hsd12, zpsbp3, gal3 and foxn5 were only expressed in ovary.

Conclusion

This study investigated the complexity of brain and gonad transcriptomes in three sex stages of the rice field eel. Integrated analysis of different gene expression and changes in signaling pathways, such as PI3K-Akt pathway, provided crucial data for further study of sex transformation mechanisms.

Altered microRNA expression patterns during the initiation and promotion stages of neonatal diethylstilbestrol-induced dysplasia/neoplasia in the hamster (Mesocricetus auratus) uterus

Treatment of Syrian hamsters on the day of birth with the prototypical endocrine disruptor and synthetic estrogen, diethylstilbestrol (DES), leads to 100% occurrence of uterine hyperplasia/dysplasia in adulthood, a large proportion of which progress to neoplasia (endometrial adenocarcinoma). Consistent with our prior gene expression analyses at the mRNA and protein levels, we now report (based on microarray, real-time polymerase chain reaction, and in situ hybridization analyses) that progression of the neonatal DES-induced dysplasia/neoplasia phenomenon in the hamster uterus also includes a spectrum of microRNA expression alterations (at both the whole-organ and cell-specific level) that differ during the initiation (upregulated miR-21, 200a, 200b, 200c, 29a, 29b, 429, 141; downregulated miR-181a) and promotion (downregulated miR-133a) stages of the phenomenon. The biological processes targeted by those differentially expressed miRNAs include pathways in cancer and adherens junction, plus regulation of the cell cycle, apoptosis, and miRNA functions, all of which are consistent with our model system phenotype. These findings underscore the need for continued efforts to identify and assess both the classical genetic and the more recently recognized epigenetic mechanisms that truly drive this and other endocrine disruption phenomena.

Hypolipidemic effect of oleanolic acid is mediated by the miR-98-5p/PGC-1β axis in high-fat diet-induced hyperlipidemic mice

Oleanolic acid (OA) is an active component of the traditional Chinese herb Olea europaea L. and has been found to exhibit a significant lipid-lowering effect; however, its direct molecular target is still unknown, which limits its clinical application and the possible structure modification to improve its beneficial functions. In this regard, we carried out the present study to identify potential hepatic targets of OA to mediate its lipid-lowering effect. We found that both acute and chronic OA treatments reduced serum levels of triglycerides, total cholesterol, and LDL cholesterol, and decreased hepatic expression levels of peroxisome proliferator-activated receptor-γ coactivator-1β (PGC-1β), which is an important regulator in maintaining hepatic lipid homeostasis, and its downstream target genes. Of note, liver-specific knockdown of PGC-1β recapitulated the hypolipidemic effects of OA. At the molecular level, OA accelerated mRNA degradation of PGC-1β. Microarray analysis revealed a host of microRNAs that potentially mediate OA-induced PGC-1β mRNA degradation, among which, miR-98-5p significantly inhibited activity of Pgc-1β 3' UTR as well as PGC-1β expression and promoted its mRNA degradation. Conversely, miR-98-5p inhibitors blunted the inhibitory effects of OA on PGC-1β expression. Collectively, our data demonstrated that OA ameliorated hyperlipidemia, likely via regulation of the miR-98-5p/PGC-1β axis.-Chen, S., Wen, X., Zhang, W., Wang, C., Liu, J., Liu, C. Hypolipidemic effect of oleanolic acid is mediated by the miR-98-5p/PGC-1β axis in high-fat diet-induced hyperlipidemic mice.

TIMPs: versatile extracellular regulators in cancer

A compelling long-term goal of cancer biology is to understand the crucial players during tumorigenesis in order to develop new interventions. Here, we review how the four non-redundant tissue inhibitors of metalloproteinases (TIMPs) regulate the pericellular proteolysis of a vast range of matrix and cell surface proteins, generating simultaneous effects on tumour architecture and cell signalling. Experimental studies demonstrate the contribution of TIMPs to the majority of cancer hallmarks, and human cancers invariably show TIMP deregulation in the tumour or stroma. Of the four TIMPs, TIMP1 overexpression or TIMP3 silencing is consistently associated with cancer progression or poor patient prognosis. Future efforts will align mouse model systems with changes in TIMPs in patients, will delineate protease-independent TIMP function, will pinpoint therapeutic targets within the TIMP-metalloproteinase-substrate network and will use TIMPs in liquid biopsy samples as biomarkers for cancer prognosis.

miR-720 is a downstream target of an ADAM8-induced ERK signaling cascade that promotes the migratory and invasive phenotype of triple-negative breast cancer cells

BACKGROUND

ADAM8 (a disintegrin and metalloproteinase 8) protein promotes the invasive and metastatic phenotype of triple-negative breast cancer (TNBC) cells. High ADAM8 expression in breast cancer patients is an independent predictor of poor prognosis. Here, we investigated whether ADAM8 regulates specific miRNAs, their roles in aggressive phenotype, and potential use as biomarkers of disease.

METHODS

Microarray analysis was performed on RNA from MDA-MB-231 cells after transient ADAM8 knockdown using TaqMan miRNA cards. Changes in miRNA levels were confirmed using two ADAM8 siRNAs in TNBC cell lines. Kinase inhibitors, β1-integrin antagonist antibody, and different forms of ADAM8 were employed to elucidate the signaling pathway required for miR-720 expression. miR-720 levels were modulated using a specific antagomiR or a mimic, and effects on aggressive phenotype of TNBC cells were determined using Boyden chamber and 3D-Matrigel outgrowth assays. Plasma was isolated from mice before and after implantation of MDA-MB-231 cells and analyzed for miR-720 levels. Serum samples of TNBC patients were evaluated for their ADAM8 and miR-720 levels.

RESULTS

We identified 68 miRNAs differentially regulated upon ADAM8 knockdown, including decreased levels of secreted miR-720. Ectopic overexpression of wild-type ADAM8 or forms that lack metalloproteinase activity similarly induced miR-720 levels. The disintegrin and cysteine-rich domains of ADAM8 were shown to induce miR-720 via activation of a β1-integrin to ERK signaling cascade. Knockdown of miR-720 led to a significant decrease in migratory and invasive abilities of TNBC cells. Conversely, miR-720 overexpression rescued these properties. A profound increase in plasma levels of miR-720 was detected 7 days after TNBC cell inoculation into mouse mammary fat pads when tumors were barely palpable. Concordantly, miR-720 levels were found to be significantly higher in serum samples of TNBC patients with high ADAM8 expression.

CONCLUSIONS

We have shown for the first time that miR-720 is induced by ADAM8 signaling via ERK and plays an essential role in promoting the aggressive phenotype of TNBCs. miR-720 is elevated in serum of patients with ADAM8-high TNBC and, in a group with other miRNAs downstream of ADAM8, holds promise as a biomarker for early detection of or treatment response of ADAM8-positive TNBCs.

Differential network analysis reveals the genome-wide landscape of estrogen receptor modulation in hormonal cancers

Several mutual information (MI)-based algorithms have been developed to identify dynamic gene-gene and function-function interactions governed by key modulators (genes, proteins, etc.). Due to intensive computation, however, these methods rely heavily on prior knowledge and are limited in genome-wide analysis. We present the modulated gene/gene set interaction (MAGIC) analysis to systematically identify genome-wide modulation of interaction networks. Based on a novel statistical test employing conjugate Fisher transformations of correlation coefficients, MAGIC features fast computation and adaption to variations of clinical cohorts. In simulated datasets MAGIC achieved greatly improved computation efficiency and overall superior performance than the MI-based method. We applied MAGIC to construct the estrogen receptor (ER) modulated gene and gene set (representing biological function) interaction networks in breast cancer. Several novel interaction hubs and functional interactions were discovered. ER+ dependent interaction between TGFβ and NFκB was further shown to be associated with patient survival. The findings were verified in independent datasets. Using MAGIC, we also assessed the essential roles of ER modulation in another hormonal cancer, ovarian cancer. Overall, MAGIC is a systematic framework for comprehensively identifying and constructing the modulated interaction networks in a whole-genome landscape. MATLAB implementation of MAGIC is available for academic uses at https://github.com/chiuyc/MAGIC.

PGRMC1 Elevation in Multiple Cancers and Essential Role in Stem Cell Survival

Cancer is one of the leading causes of death in America, and there is an urgent need for new therapeutic approaches. The progesterone receptor membrane component 1 (PGRMC1) is a cytoch-rome b₅ related protein that binds heme and is associated with signaling, apoptotic suppression and autophagy. PGRMC1 is essential for tumor formation, invasion and metastasis, and is upregulated in breast, colon, lung and thyroid tumors. In the present study, we have analyzed PGRMC1 levels in over 600 tumor sections, including a larger cohort of lung tumors than in previous studies, and report the first clinical analysis of PGRMC1 levels in human oral cavity and ovarian tumors compared to corresponding nonmalignant tissues. PGRMC1 was highly expressed in lung and ovarian cancers and correlated with patient survival. PGRMC1 has been previously associated with drug resistance, a characteristic of cancer stem cells. The stem cell theory proposes that a subset of cancerous stem cells contribute to drug resistance and tumor maintenance, and PGRMC1 was detected in lung-tumor derived stem cells. Drug treatment with a PGRMC1 inhibitor, AG-205, triggered stem cell death whereas treatment with erlotinib and the ERK inhibitor, PD98059, did not, suggesting a specific role for PGRMC1 in cancer stem cell viability. Together, our data demonstrate PGRMC1 as a potential tumor biomarker across a variety of tumors, as well as a therapeutic target for cancer stem cells.

MicroRNA-132 promotes estradiol synthesis in ovarian granulosa cells via translational repression of Nurr1

BACKGROUND

Estrogen synthesis is an important function of the mammalian ovary. Estrogen plays important roles in many biological processes, including follicular development, oocyte maturation and endometrial proliferation, and dysfunctions in estrogen synthesis contribute to the development of polycystic ovary syndrome and premature ovarian failure. Classical signaling cascades triggered by follicle-stimulating hormone induce estrogen synthesis via the upregulation of Cyp19a1 in granulosa cells (GCs). This study aimed to determine the effect of microRNA-132 (miR-132) on estradiol synthesis in GCs.

METHODS

Primary mouse GCs were collected from ovaries of 21-day-old immature ICR mice through follicle puncture. GCs were cultured and treated with the stable cyclic adenosine monophosphate analog 8-Br-cAMP or transfected with miR-132 mimics, Nurr1-specific small interfering RNA oligonucleotides and Flag-Nurr1 plasmids. Concentrations of estradiol and progesterone in culture medium were determined by an automated chemiluminescence-based assay. Quantitative real time PCR and western blot were performed to identify the effect of miR-132 on Cyp19a1, Cyp11a1 and an orphan nuclear receptor-Nurr1 expression in GCs. Direct suppression of Nurr1 via its 3'-untranslated region by miR-132 were further verified using luciferase reporter assays.

RESULTS

The expression level of miR-132 in cultured mouse GCs was significantly elevated during 48 h of treatment with 8-Br-cAMP. The synthesis of estradiol increased after the overexpression of miR-132 in mouse GCs. The real-time PCR results demonstrated that miR-132 induced the expression of Cyp19a1 significantly. Nurr1, an orphan nuclear receptor that suppresses Cyp19a1 expression, was found to be a direct target of miR-132. Nurr1 was suppressed by miR-132, as indicated by a luciferase assay and Western blotting. The knockdown of Nurr1 primarily elevated the synthesis of estradiol and partially attenuated the miR-132-induced estradiol elevation, and the ectopic expression of Flag-Nurr1 abrogated the stimulatory effect of miR-132 on estradiol synthesis in mouse GCs.

CONCLUSIONS

Our findings suggest that miR-132 is involved in the cAMP signaling pathway and promotes estradiol synthesis via the translational repression of Nurr1 in ovarian GCs.

MiR-191 modulates malignant transformation of endometriosis through regulating TIMP3

Background

Although aberrant expression of several miRNAs was found during the pathological development of endometriosis to endometriosis-associated ovarian cancer (EAOC), their roles are not fully understood. miR-191 is a miRNA significantly upregulated in endometriosis and EAOC patients. However, its downstream network is still not clear. This study explored its role in malignant transformation of endometriosis to EAOC.

Material/Methods

Tissues from 12 healthy controls, 12 patients with endometriomas, and 12 patients with EAOC were used to verify miR-191 expression by using qRT-PCR. Endometriosis cell line CRL-7566 and ovarian endometrioid carcinoma cell line CRL-11731 were used to explore the downstream regulative function of miR-191.

Results

By using tissue and serum samples from healthy, endometriosis, and EAOC participants, we confirmed that miR-191 expression was significantly higher in endometriosis and EAOC participants. Interestingly, we also observed that TIMP3 expression was negatively correlated with miR-191 expression. Overexpressing miR-191 in CRL-7566 significantly increased cell proliferation and invasion, while miR-191 knockdown in CRL-11731 cells significantly decreased cell proliferation and invasion. These modulating effects of miR-191 are achieved through its regulation of TIMP3.

Conclusions

miR-191 can directly regulate TIMP3 expression, thereby affecting cell proliferation rate and invasion ability. The miR-191-TIMP3 axis might be critical in the malignant transformation of endometriosis to EAOC.

MicroRNA-181a is involved in the regulation of human endometrial stromal cell decidualization by inhibiting Krüppel-like factor 12

BACKGROUND

The transformation of endometrium into decidua is essential for normal implantation of the blastocyst. However, the post-transcriptional regulation and the miRNAs involved in decidualization remain poorly understood. Here, we examined microRNA-181a (miR-181a) expression in decidualized human endometrial stromal cell (hESC). In addition, we investigated the functional effect of miR-181a on hESC decidualization in vitro.

METHODS

Quantitative real-time PCR (qRT-PCR) was used to detect the profile of miR-181a in decidualized hESC. qRT-PCR, enzyme-linked fluorescent assay, and immunofluorescence assay were performed to investigate decidualization marker genes' expression after enhancing or inhibition of miR-181a expression in hESC. Luciferase reporter assay, western blotting, qRT-PCR, and immunofluorescence assay were carried out to identify the relationship between miR-181a and Krüppel-like factor 12 (KLF12).

RESULTS

miR-181a expression levels increased dramatically in hESC treated with 8-Br-cAMP and MPA. Increased miR-181a expression promoted hESC decidualization-related gene expression and morphological transformation; conversely, inhibition of miR-181a expression compromised hESC decidualization in vitro. Further analysis confirmed that miR-181a interacted with the 3' untranslated region of the transcription factor KLF12 and down-regulated KLF12 at the transcriptional and translational levels. KLF12 overexpression abolished miR-181a-induced decidualization.

CONCLUSIONS

Our findings suggest that miR-181a plays a functionally important role in human endometrial stromal cell decidualization in vitro by inhibiting KLF12.

Timp3 deficient mice show resistance to developing breast cancer

Timp3 is commonly silenced in breast cancer, but mechanistic studies have identified both tumor promotion and suppression effects of this gene. We have taken a genetic approach to determine the impact of Timp3 loss on two mouse models of breast cancer. Interestingly, MMTV-PyMT Timp3^−⁄− mice have delayed tumor onset and 36% of MMTV-Neu Timp3^−⁄− mice remain tumor free. TIMP3 is a regulator of TNF signaling and similar to Timp3, Tnf or Tnfr1 loss delays early tumorigenesis. The tumor suppression in Timp3 null mice requires Tnfr1, but does not result in alterations in the local immune compartment. In the mammary gland, Timps are highly expressed in the stroma and through the transplantation of tumor cells we observe that Timp3 deficiency in the host is sufficient to delay the growth of early, but not advanced tumor cells. Together our data is the first to identify a tumor promoting role of endogenous Timp3 in vivo, the spatial and temporal windows of this effect, and its dependence on Tnfr1.

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.

Hsa-microRNA-181a is a regulator of a number of cancer genes and a biomarker for endometrial carcinoma in patients: a bioinformatic and clinical study and the therapeutic implication

The aberrant expression of human microRNA-181a-1 (hsa-miR-181a) has been implicated in the pathogenesis of various cancers, serving as an oncogene or a tumor suppressor. However, the role of hsa-miR-181a in the pathogenesis of endometrial carcinoma (EC) and its clinical significance are unclear. This study aimed to search for the molecular targets of hsa-miR-181a using bioinformatic tools and then determine the expression levels of hsa-miR-181a in normal, hyperplasia, and EC samples from humans. To predict the targets of hsa-miR-181a, ten different algorithms were used, including miRanda-mirSVR, DIANA microT v5.0, miRDB, RNA22 v2, TargetMiner, TargetScan 6.2, PicTar, MicroCosm Targets v5, and miRWALK. Two algorithms, TarBase 6.0 and miRTarBase, were used to identify the validated targets of hsa-miR-181a-5p (a mature product of hsa-miR-181a), and the web-based Database for Annotation, Visualization and Integrated Discovery (DAVID) 6.7 was used to provide biological functional interpretation of the validated targets of hsa-miR-181a-5p. A total of 78 formalin-fixed, paraffin-embedded tissue specimens from 65 patients and 13 healthy subjects were collected and examined, including normal endometrium (n=13), endometrial hyperplasia (n=18), and EC (37 type I and 10 type II EC cases). Our bioinformatic studies have showed that hsa-miR-181a might regulate a large number of target genes that are important in the regulation of critical cell processes, such as cell fate, cell survival, metabolism, and cell death. To date, 313 targets of hsa-miR-181a have been validated, and 22 of these targets are cancer genes. The precision of predictions by all the algorithms for hsa-miR-181a-1’s targets was low. Many of these genes are involved in tumorigenesis of various cancers, including EC, based on the DAVID and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. In comparison with normal endometrial tissue, the expression level of hsa-miR-181a was significantly increased in type I and type II EC (P<0.05), and type II EC exhibited a significant higher expression level of hsa-miR-181a than that in type I EC (P<0.05). In addition, there was a significant increase in the expression level of hsa-miR-181a in type II EC compared with endometrial hyperplasia (P<0.05). Taken together, these results suggest that hsa-miR-181a may serve as an oncogene in endometrial tumorigenesis and that hsa-miR-181a might be used as a new biomarker in the prediction of prognosis of EC in clinical practice. More functional and mechanistic studies are needed to validate the role of hsa-miR-181a in the development, progression, and metastasis of EC.

Role of microRNAs in cancers of the female reproductive tract: insights from recent clinical and experimental discovery studies

microRNAs (miRNAs) are small RNA molecules that represent the top of the pyramid of many tumorigenesis cascade pathways as they have the ability to affect multiple, intricate, and still undiscovered downstream targets. Understanding how miRNA molecules serve as master regulators in these important networks involved in cancer initiation and progression open up significant innovative areas for therapy and diagnosis that have been sadly lacking for deadly female reproductive tract cancers. This review will highlight the recent advances in the field of miRNAs in epithelial ovarian cancer, endometrioid endometrial cancer and squamous-cell cervical carcinoma focusing on studies associated with actual clinical information in humans. Importantly, recent miRNA profiling studies have included well-characterized clinical specimens of female reproductive tract cancers, allowing for studies correlating miRNA expression with clinical outcomes. This review will summarize the current thoughts on the role of miRNA processing in unique miRNA species present in these cancers. In addition, this review will focus on current data regarding miRNA molecules as unique biomarkers associated with clinically significant outcomes such as overall survival and chemotherapy resistance. We will also discuss why specific miRNA molecules are not recapitulated across multiple studies of the same cancer type. Although the mechanistic contributions of miRNA molecules to these clinical phenomena have been confirmed using in vitro and pre-clinical mouse model systems, these studies are truly only the beginning of our understanding of the roles miRNAs play in cancers of the female reproductive tract. This review will also highlight useful areas for future research regarding miRNAs as therapeutic targets in cancers of the female reproductive tract.

Cyclic decidualization of the human endometrium in reproductive health and failure

Decidualization denotes the transformation of endometrial stromal fibroblasts into specialized secretory decidual cells that provide a nutritive and immunoprivileged matrix essential for embryo implantation and placental development. In contrast to most mammals, decidualization of the human endometrium does not require embryo implantation. Instead, this process is driven by the postovulatory rise in progesterone levels and increasing local cAMP production. In response to falling progesterone levels, spontaneous decidualization causes menstrual shedding and cyclic regeneration of the endometrium. A growing body of evidence indicates that the shift from embryonic to maternal control of the decidual process represents a pivotal evolutionary adaptation to the challenge posed by invasive and chromosomally diverse human embryos. This concept is predicated on the ability of decidualizing stromal cells to respond to individual embryos in a manner that either promotes implantation and further development or facilitates early rejection. Furthermore, menstruation and cyclic regeneration involves stem cell recruitment and renders the endometrium intrinsically capable of adapting its decidual response to maximize reproductive success. Here we review the endocrine, paracrine, and autocrine cues that tightly govern this differentiation process. In response to activation of various signaling pathways and genome-wide chromatin remodeling, evolutionarily conserved transcriptional factors gain access to the decidua-specific regulatory circuitry. Once initiated, the decidual process is poised to transit through distinct phenotypic phases that underpin endometrial receptivity, embryo selection, and, ultimately, resolution of pregnancy. We discuss how disorders that subvert the programming, initiation, or progression of decidualization compromise reproductive health and predispose for pregnancy failure.

Progesterone receptor membrane component 1 deficiency attenuates growth while promoting chemosensitivity of human endometrial xenograft tumors

Endometrial cancer is the leading gynecologic cancer in women in the United States with 52,630 women predicted to be diagnosed with the disease in 2014. The objective of this study was to determine if progesterone (P4) receptor membrane component 1 (PGRMC1) influenced endometrial cancer cell viability in response to chemotherapy in vitro and in vivo. A lentiviral-based shRNA knockdown approach was used to generate stable PGRMC1-intact and PGRMC1-deplete Ishikawa endometrial cancer cell lines that also lacked expression of the classical progesterone receptor (PGR). Progesterone treatment inhibited mitosis of PGRMC1-intact, but not PGRMC1-deplete cells, suggesting that PGRMC1 mediates the anti-mitotic actions of P4. To test the hypothesis that PGRMC1 attenuates chemotherapy-induced apoptosis, PGRMC1-intact and PGRMC1-deplete cells were treated in vitro with vehicle, P4 (1 µM), doxorubicin (Dox, 2 µg/ml), or P4 + Dox for 48 h. Doxorubicin treatment of PGRMC1-intact cells resulted in a significant increase in cell death; however, co-treatment with P4 significantly attenuated Dox-induced cell death. This response to P4 was lost in PGRMC1-deplete cells. To extend these observations in vivo, a xenograft model was employed where PGRMC1-intact and PGRMC1-deplete endometrial tumors were generated following subcutaneous and intraperitoneal inoculation of immunocompromised NOD/SCID and nude mice, respectively. Tumors derived from PGRMC1-deplete cells grew slower than tumors from PGRMC1-intact cells. Mice harboring endometrial tumors were then given three treatments of vehicle (1:1 cremophor EL: ethanol + 0.9% saline) or chemotherapy [Paclitaxel (15 mg/kg, i.p.) followed after an interval of 30 minutes by CARBOplatin (50 mg/kg)] at five day intervals. In response to chemotherapy, tumor volume decreased approximately four-fold more in PGRMC1-deplete tumors when compared with PGRMC1-intact control tumors, suggesting that PGRMC1 promotes tumor cell viability during chemotherapeutic stress. In sum, these in vitro and in vivo findings demonstrate that PGRMC1 plays a prominent role in the growth and chemoresistance of human endometrial tumors.