MicroRNA-200c and microRNA-31 regulate proliferation, colony formation, migration and invasion in serous ovarian cancer

Dual role of microRNA-31 in human cancers; focusing on cancer pathogenesis and signaling pathways

Widespread changes in the expression of microRNAs in cancer result in abnormal gene expression for the miRNAs that control those genes, which in turn causes changes to entire molecular networks and pathways. The frequently altered miR-31, which is found in a wide range of cancers, is one cancer-related miRNA that is particularly intriguing. MiR-31 has a very complicated set of biological functions, and depending on the type of tumor, it may act both as a tumor suppressor and an oncogene. The endogenous expression levels of miR-31 appear to be a key determinant of the phenotype brought on by aberrant expression. Varied expression levels of miR-31 could affect cell growth, metastasis, drug resistance, and other process by several mechanisms like targeting BRCA1-associated protein-1 (BAP1), large tumor suppressor kinase 1 (LATS1) and protein phosphatase 2 (PP2A). This review highlights the current understanding of the genes that miR-31 targets while summarizing the complex expression patterns of miR-31 in human cancers and the diverse phenotypes brought on by altered miR-31 expression.

MiRNAs as new potential biomarkers and therapeutic targets in brain metastasis

Brain metastases represent a formidable challenge in cancer management, impacting a significant number of patients and contributing significantly to cancer-related mortality. Conventional diagnostic methods frequently fall short, underscoring the imperative for non-invasive alternatives. Non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), present promising avenues for exploration. These ncRNAs exert influence over the prognosis and treatment resistance of brain metastases, offering valuable insights into underlying mechanisms and potential therapeutic targets. Dysregulated ncRNAs have been identified in brain metastases originating from various primary cancers, unveiling opportunities for intervention and prevention. The analysis of ncRNA expression in bodily fluids, such as serum and cerebrospinal fluid, provides a noninvasive means to differentiate brain metastases from primary tumors. NcRNAs, particularly miRNAs, assume a pivotal role in orchestrating the immune response within the brain microenvironment. MiRNAs exhibit promise in diagnosing brain metastases, effectively distinguishing between normal and cancer cells, and pinpointing the tissue of origin for metastatic brain tumors. The manipulation of miRNAs holds substantial potential in cancer treatment, offering the prospect of reducing toxicity and enhancing efficacy. Given the limited treatment options and the formidable threat of brain metastases in cancer patients, non-coding RNAs, especially miRNAs, emerge as beacons of hope, serving as both diagnostic tools and therapeutic targets. Further clinical studies are imperative to validate the specificity and sensitivity of ncRNAs, potentially reshaping approaches to tackle this challenge and elevate treatment outcomes for affected patients.

Overexpression of miR-200s inhibits proliferation and invasion while increasing apoptosis in murine ovarian cancer cells

Women diagnosed with ovarian cancer frequently have a poor prognosis as their cancer is often diagnosed at more advanced stages when the cancer has metastasized. At this point surgery cannot remove all the tumor cells and while ovarian cancer cells often initially respond to chemotherapeutic agents like carboplatin and paclitaxel, resistance to these agents frequently occurs. Thus, novel therapies are required for the treatment of advanced stage ovarian cancer. One therapeutic option being explored is the regulation of non-coding RNAs such as microRNAs. An advantage of microRNAs is that they can regulate tens, hundreds and sometimes thousands of mRNAs in cells and thus may be more effective than chemotherapeutic agents or targeted therapies. To investigate the therapeutic potential of miR-200s in ovarian cancer, lentiviral vectors were used to overexpress both miR-200 clusters in two murine ovarian cancer cell lines, ID8 and 28-2. Overexpression of miR-200s reduced the expression of several mesenchymal genes and proteins, significantly inhibited proliferation as assessed by BrdU flow cytometry and significantly reduced invasion through Matrigel coated transwell inserts in both cell lines. Overexpression of miR-200s also increased basal apoptosis approximately 3-fold in both cell lines as determined by annexin V flow cytometry. Pathway analysis of RNA sequencing of control and miR-200 overexpressing ovarian cancer cells revealed that genes regulated by miR-200s were involved in processes like epithelial mesenchymal transition (EMT) and cell migration. Therefore, miR-200s can inhibit proliferation and increase apoptosis while suppressing tumor cell invasion and thus simultaneously target three key cancer pathways.

Current strategies for early epithelial ovarian cancer detection using miRNA as a potential tool

Ovarian cancer is one of the most aggressive and significant malignant tumor forms in the female reproductive system. It is the leading cause of death among gynecological cancers owing to its metastasis. Since its preliminary disease symptoms are lacking, it is imperative to develop early diagnostic biomarkers to aid in treatment optimization and personalization. In this vein, microRNAs, which are short sequence non-coding molecules, displayed great potential as highly specific and sensitive biomarker. miRNAs have been extensively advocated and proven to serve an instrumental part in the clinical management of cancer, especially ovarian cancer, by promoting the cancer cell progression, invasion, delayed apoptosis, epithelial-mesenchymal transition, metastasis of cancer cells, chemosensitivity and resistance and disease therapy. Here, we cover our present comprehension of the most up-to-date microRNA-based approaches to detect ovarian cancer, as well as current diagnostic and treatment strategies, the role of microRNAs as oncogenes or tumor suppressor genes, and their significance in ovarian cancer progression, prognosis, and therapy.

miRNA Expression Profiles in Ovarian Endometriosis and Two Types of Ovarian Cancer-Endometriosis-Associated Ovarian Cancer and High-Grade Ovarian Cancer

Endometriosis-associated ovarian cancer (EOC) consisting of endometrioid cancer and clear-cell ovarian cancer could be promoted by many factors. miRNAs, which are small, non-coding molecules of RNA, are among them. The aim of this study was to detect miRNAs connected with the malignant transformation of endometriosis. FFPE (formalin-fixed, paraffin-embedded) samples of 135 patients operated on for endometriosis and different types of ovarian cancer (EOC and HGSOC-high-grade serous ovarian cancer) were studied. Healthy ovarian tissue was used as a control group. From the expression panel of 754 miRNAs, 7 were chosen for further tests according to their ROC (receiver operating characteristic) curves: miR-1-3p, miR-125b-1-3p, miR-31-3p, miR-200b-3p, miR-502-5p, miR-503-5p and miR-548d-5p. Furthermore, other potentially important clinical data were analysed, which included age, BMI, Ca-125 concentration, miscarriages and deliveries and concomitant diseases such as hypertension, type 2 diabetes and smoking. Among the miRNAs, miR200b-3p had the lowest expression in neoplastic tissues. miR31-3p had the highest expression in women without any lesions in the ovaries. miR-502-5p and miR-548-5p did not differ between the studied groups. The examined miRNA panel generally distinguished significantly normal ovarian tissue and endometriosis, normal ovarian tissue and cancer, and endometriosis and cancer. The malignant transformation of endometriosis is dependent on different factors. miRNA changes are among them. The studied miRNA panel described well the differences between endometriosis and EOC but had no potential to differentiate types of ovarian cancer according to their origin. Therefore, examination of a broader miRNA panel is needed and might prove itself advantageous in clinical practice.

Biomarkers of endometriosis

Endometriosis is one of the most severe female reproductive disorders, affecting 6-10% of women between 18 and 35. It is a gynaecological condition where endometrial tissue develops and settles outside the uterus. The aetiology of endometriosis is primarily influenced by genetic, epigenetic, and non-genetic variables, making it highly challenging to create a therapeutic therapy explicitly targeting the ectopic tissue. The delay in the treatment is due to the limitations in the diagnostic approaches, which are restricted to invasive techniques such as laparoscopy or laparotomy. This accords to 70% of the women being diagnosed at later stages. By understanding the subject, several treatment medications have been produced to lessen the disease's symptoms. Nevertheless, endometriosis cannot be permanently cured. A viable or persuasive standard screening test for endometriosis must be utilized in a clinical context. A helpful assessment method for the early identification of endometriosis could be biomarkers. A major research priority is the identification of a biomarker that is sensitive and specific enough for detecting endometriosis. The present article has reviewed studies published on the expression of biomarkers of endometriosis. It outlines various biomarkers from different sample types, such as serum/plasma and urine, in addition to tissue. This would provide a non-invasive approach to diagnosing the disease at the initial stages without any harmful repercussions. Future high-throughput advances in science and technology are anticipated to result in the creation of a potent remedy for endometriosis. To achieve successful outcomes, it is necessary to research the discussed biomarkers that demonstrate substantial results extensively.

The role of miR-200 family in the regulation of hallmarks of cancer

MiRNAs are short non-coding RNAs that regulate gene expression post-transcriptionally contributing to the development of different diseases including cancer. The miR-200 family consists of five members, miR-200a, miR-200b, miR-200c, miR-141, and miR-429. Their expression is dysregulated in cancer tissue and their level is altered in the body fluids of cancer patients. Moreover, the levels of miR-200 family members correlate with clinical parameters such as cancer patients' survival which makes them potentially useful as diagnostic and prognostic biomarkers. MiRNAs can act as either oncomiRs or tumor suppressor miRNAs depending on the target genes and their role in the regulation of key oncogenic signaling pathways. In most types of cancer, the miR-200 family acts as tumor suppressor miRNA and regulates all features of cancer. In this review, we summarized the expression pattern of the miR-200 family in different types of cancer and their potential utility as biomarkers. Moreover, we comprehensively described the role of miR-200 family members in the regulation of all hallmarks of cancer proposed by Hanahan and Weinberg with the focus on the epithelial-mesenchymal transition, invasiveness, and metastasis of tumor cells.

The Advances in Epigenetics for Cancer Radiotherapy

Cancer is an important factor threatening human life and health; in recent years, its morbidity and mortality remain high and demosntrate an upward trend. It is of great significance to study its pathogenesis and targeted therapy. As the complex mechanisms of epigenetic modification has been increasingly discovered, they are more closely related to the occurrence and development of cancer. As a reversible response, epigenetic modification is of great significance for the improvement of classical therapeutic measures and the discovery of new therapeutic targets. It has become a research focusto explore the multi-level mechanisms of RNA, DNA, chromatin and proteins. As an important means of cancer treatment, radiotherapy has made great progress in technology, methods, means and targeted sensitization after years of rapid development, and even research on radiotherapy based on epigenetic modification is rampant. A series of epigenetic effects of radiation on DNA methylation, histone modification, chromosome remodeling, RNA modification and non-coding RNA during radiotherapy affects the therapeutic effects and prognosis. Starting from the epigenetic mechanism of tumorigenesis, this paper reviews the latest progress in the mechanism of interaction between epigenetic modification and cancer radiotherapy and briefly introduces the main types, mechanisms and applications of epigenetic modifiers used for radiotherapy sensitization in order to explore a more individual and dynamic approach of cancer treatment based on epigenetic mechanism. This study strives to make a modest contribution to the progress of human disease research.

Evaluation of Diagnostic Potential of Epigenetically Deregulated MiRNAs in Epithelial Ovarian Cancer

Background

Epithelial ovarian cancer (EOC) is one of the most lethal gynecological malignancies among women worldwide. Early diagnosis of EOC could help in ovarian cancer management. MicroRNAs, a class of small non-coding RNA molecules, are known to be involved in post-transcriptional regulation of ~60% of human genes. Aberrantly expressed miRNAs associated with disease progression are confined in lipid or lipoprotein and secreted as extracellular miRNA in body fluid such as plasma, serum, and urine. MiRNAs are stably present in the circulation and recently have gained an importance to serve as a minimally invasive biomarker for early detection of epithelial ovarian cancer.

Methods

Genome-wide methylation pattern of six EOC and two normal ovarian tissue samples revealed differential methylation regions of miRNA gene promoter through MeDIP-NGS sequencing. Based on log2FC and p-value, three hypomethylated miRNAs (miR-205, miR-200c, and miR-141) known to have a potential role in ovarian cancer progression were selected for expression analysis through qRT-PCR. The expression of selected miRNAs was analyzed in 115 tissue (85 EOC, 30 normal) and 65 matched serum (51 EOC and 14 normal) samples.

Results

All three miRNAs (miR-205, miR-200c, and miR-141) showed significantly higher expression in both tissue and serum cohorts when compared with normal controls (p < 0.0001). The receiver operating characteristic curve analysis of miR-205, miR-200c, and miR-141 has area under the curve (AUC) values of 87.6 (p < 0.0001), 78.2 (p < 0.0001), and 86.0 (p < 0.0001), respectively; in advance-stage serum samples, however, ROC has AUC values of 88.1 (p < 0.0001), 78.9 (p < 0.0001), and 86.7 (p < 0.0001), respectively, in early-stage serum samples. The combined diagnostic potential of the three miRNAs in advance-stage serum samples and early-stage serum samples has AUC values of 95.9 (95% CI: 0.925-1.012; sensitivity = 96.6% and specificity = 80.0%) and 98.1 (95% CI: 0.941-1.021; sensitivity = 90.5% and specificity = 100%), respectively.

Conclusion

Our data correlate the epigenetic deregulation of the miRNA genes with their expression. In addition, the miRNA panel (miR-205 + miR-200c + miR-141) has a much higher AUC, sensitivity, and specificity to predict EOC at an early stage in both tissue and serum samples.

Circulating Exosomal miRNAs as Biomarkers in Epithelial Ovarian Cancer

Failure to detect early-stage epithelial ovarian cancer (EOC) is a major contributing factor to its low survival rate. Increasing evidence suggests that different subtypes of EOC may behave as distinct diseases due to their different cells of origins, histology and treatment responses. Therefore, the identification of EOC subtype-specific biomarkers that can early detect the disease should be clinically beneficial. Exosomes are extracellular vesicles secreted by different types of cells and carry biological molecules, which play important roles in cell-cell communication and regulation of various biological processes. Multiple studies have proposed that exosomal miRNAs present in the circulation are good biomarkers for non-invasive early detection of cancer. In this review, the potential use of exosomal miRNAs as early detection biomarkers for EOCs and their accuracy are discussed. We also review the differential expression of circulating exosomal miRNAs and cell-free miRNAs between different biofluid sources, i.e., plasma and serum, and touch on the issue of endogenous reference miRNA selection. Additionally, the current clinical trials using miRNAs for detecting EOCs are summarized. In conclusion, circulating exosomal miRNAs as the non-invasive biomarkers have a high potential for early detection of EOC and its subtypes, and are likely to be clinically important in the future.

Ascites in ovarian cancer: MicroRNA deregulations and their potential roles in ovarian carcinogenesis

Ovarian cancer comprises the most lethal gynecologic malignancy and is accompanied by the high potential for the incidence of metastasis, recurrence and chemotherapy resistance, often associated with a formation of ascitic fluid. The differentially expressed ascites-derived microRNAs may be linked to ovarian carcinogenesis. The article focuses on a number of miRNAs that share a common expression pattern as determined by independent studies using ascites samples and with regard to their functions and outcomes in experimental and clinical investigations.Let-7b and miR-143 have featured as tumor suppressors in ovarian cancer, which is in line with data on other types of cancer. Although two miRNAs, i.e. miR-26a-5p and miR-145-5p, act principally as tumor suppressor miRNAs, they occasionally exhibit oncogenic roles. The performance of miR-95-3p, upregulated in ascites, is open to debate given the current lack of supportive data on ovarian cancer; however, data on other cancers indicates its probable oncogenic role. Different findings have been reported for miR-182-5p and miR-200c-3p; in addition to their presumed oncogenic roles, contrasting findings have indicated their ambivalent functions. Further research is required for the identification and evaluation of the potential of specific miRNAs in the diagnosis, prediction, treatment and outcomes of ovarian cancer patients.

Modulation of Cellular MicroRNA by HIV-1 in Burkitt Lymphoma Cells-A Pathway to Promoting Oncogenesis

Viruses and viral components have been shown to manipulate the expression of host microRNAs (miRNAs) to their advantage, and in some cases to play essential roles in cancer pathogenesis. Burkitt lymphoma (BL), a highly aggressive B-cell derived cancer, is significantly over-represented among people infected with HIV. This study adds to accumulating evidence demonstrating that the virus plays a direct role in promoting oncogenesis. A custom miRNA PCR was used to identify 32 miRNAs that were differently expressed in Burkitt lymphoma cells exposed to HIV-1, with a majority of these being associated with oncogenic processes. Of those, hsa-miR-200c-3p, a miRNA that plays a crucial role in cancer cell migration, was found to be significantly downregulated in both the array and in single-tube validation assays. Using an in vitro transwell system we found that this downregulation correlated with significantly enhanced migration of BL cells exposed to HIV-1. Furthermore, the expression of the ZEB1 and ZEB2 transcription factors, which are promotors of tumour invasion and metastasis, and which are direct targets of hsa-miR-200c-3p, were found to be enhanced in these cells. This study therefore identifies novel miRNAs as role players in the development of HIV-associated BL, with one of these miRNAs, hsa-miR-200c-3p, being a candidate for further clinical studies as a potential biomarker for prognosis in patients with Burkitt lymphoma, who are HIV positive.

Clinical significance of microRNA-200 and let-7 families expression assessment in patients with ovarian cancer

Ovarian cancer (OC) represents the most lethal malignancy in gynaecologic oncology practice and shows a high recurrence rate due to its early chemoresistance to first-line chemotherapy. Yet, timely selection of the correct treatment strategy is likely to prolong a patient's survival. MicroRNAs (miRNAs) are a class of short non-coding RNAs responsible for the expression of 30%-60% of human genes. In numerous studies, miRNAs have been used to provide the overall prognosis for patients and analyse the process's prevalence and responses to chemotherapy. In particular, miRNAs as markers for predicting the sensitivity of OC to platinum- and taxane-based chemotherapeutics can significantly improve the treatment efficacy. This article highlights two families of miRNAs: miR-200 and let-7, which are promising for further research on OC and its chemosensitivity.

Current Implications of microRNAs in Genome Stability and Stress Responses of Ovarian Cancer

Genomic alterations and aberrant DNA damage signaling are hallmarks of ovarian cancer (OC), the leading cause of mortality among gynecological cancers worldwide. Owing to the lack of specific symptoms and late-stage diagnosis, survival chances of patients are significantly reduced. Poly (ADP-ribose) polymerase (PARP) inhibitors and replication stress response inhibitors present attractive therapeutic strategies for OC. Recent research has focused on ovarian cancer-associated microRNAs (miRNAs) that play significant regulatory roles in various cellular processes. While miRNAs have been shown to participate in regulation of tumorigenesis and drug responses through modulating the DNA damage response (DDR), little is known about their potential influence on sensitivity to chemotherapy. The main objective of this review is to summarize recent findings on the utility of miRNAs as cancer biomarkers, in particular, ovarian cancer, and their regulation of DDR or modified replication stress response proteins. We further discuss the suppressive and promotional effects of various miRNAs on ovarian cancer and their participation in cell cycle disturbance, response to DNA damage, and therapeutic functions in multiple cancer types, with particular focus on ovarian cancer. Improved understanding of the mechanisms by which miRNAs regulate drug resistance should facilitate the development of effective combination therapies for ovarian cancer.

Oncogenic Role of miR-200c-3p in High-Grade Serous Ovarian Cancer Progression via Targeting the 3'-Untranslated Region of DLC1

High-grade serous ovarian cancer (HGSC) is the most common ovarian cancer with highly metastatic properties. A small non-coding RNA, microRNA (miRNA) was discovered to be a major regulator in many types of cancers through binding at the 3′-untranslated region (3′UTR), leading to degradation of the mRNA. In this study, we sought to investigate the underlying mechanisms involved in the dysregulation of miR-200c-3p in HGSC progression and metastasis. We identified the upregulation of miR-200c-3p expression in different stages of HGSC clinical samples and the downregulation of the tumor suppressor gene, Deleted in Liver Cancer 1 (DLC1), expression. Over expression of miR-200c-3p in HGSC cell lines downregulated DLC1 but upregulated the epithelial marker, E-cadherin (CDH1). Based on in silico analysis, two putative binding sites were found within the 3′UTR of DLC1, and we confirmed the direct binding of miR-200c-3p to the target binding motif at position 1488–1495 bp of 3′UTR of DLC1 by luciferase reporter assay in a SKOV3 cell line co-transfected with vectors and miR-200c-3p mimic. These data showed that miR-200c-3p regulated the progression of HGSC by regulating DLC1 expression post-transcription and can be considered as a promising target for therapeutic purposes.

MicroRNA Dysregulation in Parkinson's Disease: A Narrative Review

Parkinson’s disease (PD) is a severely debilitating neurodegenerative disease, affecting the motor system, leading to resting tremor, cogwheel rigidity, bradykinesia, walking and gait difficulties, and postural instability. The severe loss of dopaminergic neurons in the substantia nigra pars compacta causes striatal dopamine deficiency and the presence of Lewy bodies indicates a pathological hallmark of PD. Although the current treatment of PD aims to preserve dopaminergic neurons or to replace dopamine depletion in the brain, it is notable that complete recovery from the disease is yet to be achieved. Given the complexity and multisystem effects of PD, the underlying mechanisms of PD pathogenesis are yet to be elucidated. The advancement of medical technologies has given some insights in understanding the mechanism and potential treatment of PD with a special interest in the role of microRNAs (miRNAs) to unravel the pathophysiology of PD. In PD patients, it was found that striatal brain tissue and dopaminergic neurons from the substantia nigra demonstrated dysregulated miRNAs expression profiles. Hence, dysregulation of miRNAs may contribute to the pathogenesis of PD through modulation of PD-associated gene and protein expression. This review will discuss recent findings on PD-associated miRNAs dysregulation, from the regulation of PD-associated genes, dopaminergic neuron survival, α-synuclein-induced inflammation and circulating miRNAs. The next section of this review also provides an update on the potential uses of miRNAs as diagnostic biomarkers and therapeutic tools for PD.

Small Non-Coding-RNA in Gynecological Malignancies

Gynecologic malignancies, which include cancers of the cervix, ovary, uterus, vulva, vagina, and fallopian tube, are among the leading causes of female mortality worldwide, with the most prevalent being endometrial, ovarian, and cervical cancer. Gynecologic malignancies are complex, heterogeneous diseases, and despite extensive research efforts, the molecular mechanisms underlying their development and pathology remain largely unclear. Currently, mechanistic and therapeutic research in cancer is largely focused on protein targets that are encoded by about 1% of the human genome. Our current understanding of 99% of the genome, which includes noncoding RNA, is limited. The discovery of tens of thousands of noncoding RNAs (ncRNAs), possessing either structural or regulatory functions, has fundamentally altered our understanding of genetics, physiology, pathophysiology, and disease treatment as they relate to gynecologic malignancies. In recent years, it has become clear that ncRNAs are relatively stable, and can serve as biomarkers for cancer diagnosis and prognosis, as well as guide therapy choices. Here we discuss the role of small non-coding RNAs, i.e., microRNAs (miRs), P-Element induced wimpy testis interacting (PIWI) RNAs (piRNAs), and tRNA-derived small RNAs in gynecological malignancies, specifically focusing on ovarian, endometrial, and cervical cancer.

Circulating and Tissue microRNAs as Biomarkers for Ovarian Cancer Prognosis

Ovarian cancer (OC) is one of the most common cancers globally with a high rate of cancer- associated mortality. OC may be classified into epithelial cell neoplasms, germ cell neoplasms and stromal cell neoplasms. The five-year survival in the early and advanced stages of disease is approximately 90% and 15%, respectively. microRNAs are short, single-stranded, non-coding ribonucleic acid (RNA). miRNAs play critical roles in post transcriptionally regulations of gene expression. miRNAs are found in different tissues and body fluids. In carcinogenesis the expression of miRNAs are altered. Recent studies have revealed that there is a relationship between alteration of miRNAs expression and the prognosis of patients with OC. The aim of this review was to summarize the findings of recent studies that have investigated the expression of circulating and tissue miRNAs as novel biomarkers in the prognosis of OC.

Roles of a TMPO-AS1/microRNA-200c/TMEFF2 ceRNA network in the malignant behaviors and 5-FU resistance of ovarian cancer cells

Competing endogenous RNA (ceRNA) networks consisted of long non-coding RNA (lncRNA), microRNA (miRNA) and mRNAs have aroused great interests recently. The current study aims to probe the mechanisms of lncRNA TMPO-AS1 in ovarian cancer (OC) development. A 5-fluorouracil (5-FU)-resistant subline of OC SKOV3 cells was developed, and differentially expressed lncRNAs in OC tissues and SKOV3 cells were analyzed. The miRNAs, genes and signaling pathways interacted with TMPO-AS1 were predicted and validated. TMPO-AS1 and the validated miRNA were inhibited to analyze their roles in malignant behaviors and 5-FU resistance of OC cells. In vivo studies were performed by inducing xenograft tumors in nude mice. Consequently, TMPO-AS1 was highly expressed in OC tissues and SKOV3 cells. TMPO-AS1 regulated transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2) through sponging miR-200c in OC cells, during which the PI3K/Akt signaling pathway was activated. Silenced TMPO-AS1 and over-expressed miR-200c inhibited epithelial-mesenchymal transition (EMT), invasion, migration and 5-FU resistance of OC cells. This study demonstrated that silencing of TMPO-AS1 might attenuate OC progression through inhibiting the invasion, metastasis and drug resistance of OC cells via the miR-200c/TMEFF2 network and the disruption of the PI3K/Akt signaling pathway.

MicroRNA Regulation of the Small Rho GTPase Regulators-Complexities and Opportunities in Targeting Cancer Metastasis

The small Rho GTPases regulate important cellular processes that affect cancer metastasis, such as cell survival and proliferation, actin dynamics, adhesion, migration, invasion and transcriptional activation. The Rho GTPases function as molecular switches cycling between an active GTP-bound and inactive guanosine diphosphate (GDP)-bound conformation. It is known that Rho GTPase activities are mainly regulated by guanine nucleotide exchange factors (RhoGEFs), GTPase-activating proteins (RhoGAPs), GDP dissociation inhibitors (RhoGDIs) and guanine nucleotide exchange modifiers (GEMs). These Rho GTPase regulators are often dysregulated in cancer; however, the underlying mechanisms are not well understood. MicroRNAs (miRNAs), a large family of small non-coding RNAs that negatively regulate protein-coding gene expression, have been shown to play important roles in cancer metastasis. Recent studies showed that miRNAs are capable of directly targeting RhoGAPs, RhoGEFs, and RhoGDIs, and regulate the activities of Rho GTPases. This not only provides new evidence for the critical role of miRNA dysregulation in cancer metastasis, it also reveals novel mechanisms for Rho GTPase regulation. This review summarizes recent exciting findings showing that miRNAs play important roles in regulating Rho GTPase regulators (RhoGEFs, RhoGAPs, RhoGDIs), thus affecting Rho GTPase activities and cancer metastasis. The potential opportunities and challenges for targeting miRNAs and Rho GTPase regulators in treating cancer metastasis are also discussed. A comprehensive list of the currently validated miRNA-targeting of small Rho GTPase regulators is presented as a reference resource.

Inhibition of miR-141 and miR-200a Increase DLC-1 and ZEB2 Expression, Enhance Migration and Invasion in Metastatic Serous Ovarian Cancer

The role of microRNA (miRNA) in ovarian cancer has been extensively studied as a regulator for its targeted genes. However, its specific role in metastatic serous ovarian cancer (SOC) is yet to be explored. This paper aims to investigate the differentially expressed miRNAs in metastatic SOC compared to normal. Locked nucleic acid PCR was performed to profile miRNA expression in 11 snap frozen metastatic SOC and 13 normal ovarian tissues. Functional analysis and regulation of their targeted genes were assessed in vitro. Forty-eight miRNAs were significantly differentially expressed in metastatic SOC as compared to normal. MiR-19a is a novel miRNA to be upregulated in metastatic SOC compared to normal. DLC1 is possibly regulated by miR-141 in SOC. MiR-141 inhibition led to significantly reduced cell viability. Cell migration and invasion were significantly increased following miRNA inhibition. This study showed the aberrantly expressed miRNAs in metastatic SOC and the roles of miRNAs in the regulation of their targeted genes and ovarian carcinogenesis.

Inhibition of miR-214-3p Aids in Preventing Epithelial Ovarian Cancer Malignancy by Increasing the Expression of LHX6

In human epithelial ovarian cancer (EOC), various miRNAs can function as either oncogenes or tumor suppressor genes. We investigated miRNAs known to be involved in EOC progression and analyzed their expression in tissues and serum-derived exosomes from benign serous cystadenoma, borderline serous tumor, low-grade serous ovarian cancer, and high-grade serous ovarian cancer patients (HGSO). The HGSO group was divided based on the platinum-free interval, which is defined as the duration from the completion of platinum-based chemotherapy to recurrence. We also analyzed the mRNA levels of target genes that candidate miRNAs might regulate in patient tissues. miR-214-3p was highly expressed in tissues and exosomes derived from EOC with high malignancy and also found to regulate the expression of LIM homeobox domain 6 (LHX6) mRNA. Serum exosomal levels of miR-214-3p were significantly increased in platinum-resistant HGSO (25.2-fold, p < 0.001) compared to the exosomal expression of benign tumor patients. On transfection of miR-214-3p inhibitor in EOC cells, cell proliferation was inhibited while apoptotic cell death was increased. Collectively, we suggest that miR-214-3p in serum exosomes can be a potential biomarker for the diagnosis and prognosis of ovarian tumor, and its inhibition can be a supportive treatment for EOC.

Serum exosomal miRNA-145 and miRNA-200c as promising biomarkers for preoperative diagnosis of ovarian carcinomas

Background: Exosomes are extracellular microvesicles that are released by most cells and widely distributed in various body fluids. Malignant cells secrete large amounts of exosomes containing various molecular constituents reflecting the originating tumor. We investigated the difference in microRNA (miRNA) expression in serum exosomes from the patients with benign, borderline and malignant ovarian masses to assess the diagnostic relevance of serum exosomal miRNAs as biomarkers for preoperative diagnosis of ovarian carcinoma.

Methods: A total of 68 cases of ovarian masses were enrolled, comprising benign ovarian cysts (benign; n=10), borderline ovarian tumors (BOT, n=10), high-grade serous ovarian carcinomas (HGSOC, n=39) and non-HGSOCs (n=9). Exosomal RNA was extracted from the serum, and expression levels of seven miRNAs (miRNA-21, -93, -141, -145, -200a, -200b and -200c), which were reportedly dysregulated in serous ovarian cancer in previous studies, were quantified by real-time PCR, and compared between the four groups.

Results: MiR-93, -145, and -200c, showed significantly higher expression in serum exosomes of the cancer group (HGSOC and non-HGSOC) than of the non-cancer group (benign and BOT; all p<0.05). The remaining three miRs (miR-141, -200a, and -200b) were expressed at extremely low levels, and not appropriate as serological biomarkers. To test discrimination of cancer from non-cancer, the area under the receiver operating characteristic curves determined for cancer antigen 125 (CA125), miR-145, miR-200c, miR-21, and miR-93 were 0.801 (p<0.001), 0.910 (p<0.001), 0.802 (p<0.001), 0.585 (p=0.303), and 0.755 (p=0.002), respectively. MiR-145 showed superior sensitivity (91.6%), and miR-200c showed superior specificity (90.0%), compared with CA125.

Conclusion: Expression of exosomal miR-93, miR-145 and miR-200c was significantly elevated in the serum of ovarian cancer patients. Serum exosomal miR-145 in particular appeared to be the most promising biomarker for preoperative diagnosis of ovarian cancer.

Expression and prognostic significance of microRNAs in Korean patients with myelodysplastic syndrome

BACKGROUND/AIMS

Various alterations of microRNA (miRNA) expression have been reported in myelodysplastic syndrome (MDS). We aimed to investigate the unique patterns and prognostic significance of miRNA expression in Korean patients with MDS.

METHODS

Bone marrow mononuclear cells were collected from eight healthy controls and 26 patients with MDS, and miRNAs were isolated and assessed via quantitative real-time polymerase chain reaction for selected miRNAs, including miR-21, miR-124a, miR-126, miR-146b-5p, miR-155, miR-182, miR-200c, miR-342-5p, miR-708, and Let-7a.

RESULTS

MiR-124a, miR-155, miR-182, miR-200c, miR-342-5p, and Let-7a were significantly underexpressed in patients with MDS, compared to healthy controls. MiR-21, miR-126, 146b-5p, and miR-155 transcript levels were significantly lower in international prognostic scoring system lower (low and intermediate-1) risk MDS than in higher (intermediate-2 and high) risk MDS. Higher expression levels of miR-126 and miR-155 correlated with significantly shorter overall survival and leukemia-free survival. Higher miR-124a expression also tended to be related to shorter survivals.

CONCLUSION

Although our study was limited by the relatively small number of patients included, we identified several miRNAs associated with pathogenesis, leukemic transformation, and prognosis in MDS.

Inhibition of glioblastoma cell invasion by hsa-miR-145-5p and hsa-miR-31-5p co-overexpression in human mesenchymal stem cells

OBJECTIVE

Human bone marrow–derived mesenchymal stem cells (hMSCs) show tropism for brain tumors and may be a useful vehicle for drug or gene delivery to malignant gliomas. Recently, some microRNAs (miRNAs) have been shown to suppress the invasiveness of malignant gliomas.

METHODS

To test their potential to become vehicles for the delivery of miRNA to malignant gliomas, hMSCs were engineered so that hMSC secretion of miRNAs that inhibit glioma cell invasion was enabled without altering the hMSC tropism for glioma cells.

RESULTS

In coculture, hMSCs cotransfected with hsa-miR-145-5p and -31-5p miRNAs showed markedly reduced invasion by U87 glioma cells in a contact-dependent manner both in vitro and ex vivo, with invasion of hMSCs cotransfected with these 2 miRNAs by the U87 cells reduced to 60.7% compared with control cells. According to a Matrigel invasion assay, the tropism of the hMSCs for U87 cells was not affected. In glioma cell lines U251 and LN229, hMSCs exhibited tropism in vivo, and invasion of hMSCs cotransfected with hsa-miR-145-5p and -31-5p was also significantly less than that of control cells. When U87 cells were coimplanted into the striatum of organotypic rat brain slices with hMSCs cotransfected with hsa-miR-145 and -31-5p, the relative invasive area decreased by 37.1%; interestingly, these U87 cells showed a change to a rounded morphology that was apparent at the invasion front. Whole-genome microarray analysis of the expression levels of 58,341 genes revealed that the co-overexpression of hsa-miR-145-5p and -31-5p downregulated FSCN1 expression in U87 cells.

CONCLUSIONS

This study demonstrates that miRNA overexpression in hMSCs can alter the function of glioma cells via contact-dependent transfer. Co-overexpression of multiple miRNAs may be a useful and novel therapeutic strategy. The study results suggest that hMSCs can be applied as a delivery vehicle for miRNAs.

MicroRNA-31 Reduces the Motility of Proinflammatory T Helper 1 Lymphocytes

Proinflammatory type 1 T helper (Th1) cells are enriched in inflamed tissues and contribute to the maintenance of chronic inflammation in rheumatic diseases. Here we show that the microRNA- (miR-) 31 is upregulated in murine Th1 cells with a history of repeated reactivation and in memory Th cells isolated from the synovial fluid of patients with rheumatic joint disease. Knock-down of miR-31 resulted in the upregulation of genes associated with cytoskeletal rearrangement and motility and induced the expression of target genes involved in T cell activation, chemokine receptor- and integrin-signaling. Accordingly, inhibition of miR-31 resulted in increased migratory activity of repeatedly activated Th1 cells. The transcription factors T-bet and FOXO1 act as positive and negative regulators of T cell receptor (TCR)-mediated miR-31 expression, respectively. Taken together, our data show that a gene regulatory network involving miR-31, T-bet, and FOXO1 controls the migratory behavior of proinflammatory Th1 cells.

Dysregulation of key microRNAs in pancreatic cancer development

Pancreatic cancer (PC) is mentioned as one of the fourth major cause of cancer-related deaths and also is considered as one of the most malignancies worldwide. Sadly, widely metastasis is frequently observed at the time of PC detection and there are, thereby, almost poor prognosis and ineffective treatment in PC patients. microRNAs (miRNAs), a group of short non-coding RNAs, regulate various cellular and developmental mechanisms, such as cell growth, proliferation, apoptosis, differentiation and angiogenesis. Also, they have essential roles even on the progression of different human and animal diseases. In recent years, extensive studies confirmed the important role of miRNAs in various steps of PC developments, including; tumor initiation, invasion and metastasis, which can use valuably for cancer detection, prognosis and therapy. Therefore, the present study reviewed the new recent investigations in miRNAs involvement in the biology of PC associated with their clinical implications.

Clinical importance of the EMSY gene expression and polymorphisms in ovarian cancer

EMSY, a BRCA2–associated protein, is amplified and overexpressed in various sporadic cancers. This is the first study assessing the clinical impact of its expression and polymorphisms on ovarian cancer (OvCa) outcome in the context of the chemotherapy regimen used. In 134 frozen OvCa samples, we assessed EMSY mRNA expression with Reverse Transcription-quantitative PCR, and also investigated the EMSY gene sequence using SSCP and/or PCR-sequencing. Clinical relevance of changes in EMSY mRNA expression and DNA sequence was evaluated in two subgroups treated with either taxane/platinum (TP, n=102) or platinum/cyclophosphamide (PC, n=32). High EMSY expression negatively affected overall survival (OS), disease-free survival (DFS) and sensitivity to treatment (PS) in the TP-treated subgroup (p-values: 0.001, 0.002 and 0.010, respectively). Accordingly, our OvCa cell line studies showed that the EMSY gene knockdown sensitized A2780 and IGROV1 cells to paclitaxel. Interestingly, EMSY mRNA expression in surviving cells was similar as in the control cells. Additionally, we identified 24 sequence alterations in the EMSY gene, including the previously undescribed: c.720G>C, p.(Lys240Asn); c.1860G>A, p.(Lys620Lys); c.246-76A>G; c.421+68A>C. In the PC-treated subgroup, a heterozygous genotype comprising five SNPs (rs4300410, rs3814711, rs4245443, rs2508740, rs2513523) negatively correlated with OS (p-value=0.009). The same SNPs exhibited adverse borderline associations with PS in the TP-treated subgroup. This is the first study providing evidence that high EMSY mRNA expression is a negative prognostic and predictive factor in OvCa patients treated with TP, and that the clinical outcome may hinge on certain SNPs in the EMSY gene as well.

miRNA-200a/c as potential biomarker in epithelial ovarian cancer (EOC): evidence based on miRNA meta-signature and clinical investigations

Extensive effort has been put on miRNA expression signatures in epithelial ovarian cancer (EOC). Unfortunately, consistent conclusion rarely yielded from diverse studies, mainly due to the high inter-lab variability and small sample sizes. To overcome above limitations, an integrated analysis of miRNA expression signature was performed by employing Robust Rank Aggregation (RRA) method. Diagnostic analysis, Kaplan-Meier survival curves and pathway enrichment analysis were used to investigate the clinical values and biological functions of meta-signature miRNAs. A total of 519 EOC and 248 noncancerous samples were included. Seven mostly dysregulated miRNAs were identified by RRA method and two miRNAs (miR-200a-3p and miR-200c-3p) remained statistically significant after Bonferroni-correction. Diagnostic meta-analysis showed reliable diagnostic capacity of miR-200a-3p (with a pooled sensitivity of 0.84 and specificity of 0.83) and miR-200c-3p (with a pooled sensitivity of 0.75 and specificity of 0.66) for EOC. Pathway enrichment analysis and expression correlation analysis suggested miR-200a/c might contribute EOC progression by affecting cellular adhesion process. Kaplan-Meier survival analysis based on two independent cohorts revealed a strong association between miR-200a/c and overall survival in EOC patients. miR-200a/c was identified as the mostly dysregulated miRNAs in EOC and might be novel diagnostic and prognostic biomarkers for patients with EOC.

Regulatory network involving miRNAs and genes in serous ovarian carcinoma

Serous ovarian carcinoma (SOC) is one of the most life-threatening types of gynecological malignancy, but the pathogenesis of SOC remains unknown. Previous studies have indicated that differentially expressed genes and microRNAs (miRNAs) serve important functions in SOC. However, genes and miRNAs are identified in a disperse form, and limited information is known about the regulatory association between miRNAs and genes in SOC. In the present study, three regulatory networks were hierarchically constructed, including a differentially-expressed network, a related network and a global network to reveal associations between each factor. In each network, there were three types of factors, which were genes, miRNAs and transcription factors that interact with each other. Focus was placed on the differentially-expressed network, in which all genes and miRNAs were differentially expressed and therefore may have affected the development of SOC. Following the comparison and analysis between the three networks, a number of signaling pathways which demonstrated differentially expressed elements were highlighted. Subsequently, the upstream and downstream elements of differentially expressed miRNAs and genes were listed, and a number of key elements (differentially expressed miRNAs, genes and TFs predicted using the P-match method) were analyzed. The differentially expressed network partially illuminated the pathogenesis of SOC. It was hypothesized that if there was no differential expression of miRNAs and genes, SOC may be prevented and treatment may be identified. The present study provided a theoretical foundation for gene therapy for SOC.

MicroRNAs in gynecological cancers: Small molecules with big implications

Gynecological cancers (GCs) are often diagnosed at advanced stages, limiting the efficacy of available therapeutic options. Thus, there remains an urgent and unmet need for innovative research for the efficient clinical management of GC patients. Research over past several years has revealed the enormous promise of miRNAs. These small non-coding RNAs can aid in the diagnosis, prognosis and therapy of all major GCs, viz., ovarian cancers, cervical cancers and endometrial cancers. Mechanistic details of the miRNAs-mediated regulation of multiple biological functions are under constant investigation, and a number of miRNAs are now believed to influence growth, proliferation, invasion, metastasis, chemoresistance and the relapse of different GCs. Modulation of tumor microenvironment by miRNAs can possibly explain some of their reported biological effects. miRNA signatures have been proposed as biomarkers for the early detection of GCs, even the various subtypes of individual GCs. miRNA signatures are also being pursued as predictors of response to therapies. This review catalogs the knowledge gained from collective studies, so as to assess the progress made so far. It is time to ponder over the knowledge gained, so that more meaningful pre-clinical and translational studies can be designed to better realize the potential that miRNAs have to offer.

miR-31a-5p promotes postnatal cardiomyocyte proliferation by targeting RhoBTB1

A limited number of microRNAs (miRNAs, miRs) have been reported to control postnatal cardiomyocyte proliferation, but their strong regulatory effects suggest a possible therapeutic approach to stimulate regenerative capacity in the diseased myocardium. This study aimed to investigate the miRNAs responsible for postnatal cardiomyocyte proliferation and their downstream targets. Here, we compared miRNA profiles in cardiomyocytes between postnatal day 0 (P0) and day 10 (P10) using miRNA arrays, and found that 21 miRNAs were upregulated at P10, whereas 11 were downregulated. Among them, miR-31a-5p was identified as being able to promote cardiomyocyte proliferation as determined by proliferating cell nuclear antigen (PCNA) expression, double immunofluorescent labeling for α-actinin and 5-ethynyl-2-deoxyuridine (EdU) or Ki-67, and cell number counting, whereas miR-31a-5p inhibition could reduce their levels. RhoBTB1 was identified as a target gene of miR-31a-5p, mediating the regulatory effect of miR-31a-5p in cardiomyocyte proliferation. Importantly, neonatal rats injected with a miR-31a-5p antagomir at day 0 for three consecutive days exhibited reduced expression of markers of cardiomyocyte proliferation including PCNA expression and double immunofluorescent labeling for α-actinin and EdU, Ki-67 or phospho-histone-H3. In conclusion, miR-31a-5p controls postnatal cardiomyocyte proliferation by targeting RhoBTB1, and increasing miR-31a-5p level might be a novel therapeutic strategy for enhancing cardiac reparative processes.

Molecular Mechanisms of Ovarian Carcinoma Metastasis: Key Genes and Regulatory MicroRNAs

Metastasis of primary tumors progresses stepwise - from change in biochemistry, morphology, and migratory patterns of tumor cells to the emergence of receptors on their surface that facilitate directional migration to target organs followed by the formation of a specific microenvironment in a target organ that helps attachment and survival of metastatic cells. A set of specific genes and signaling pathways mediate this process under control of microRNA. The molecular mechanisms underlying biological processes associated with tumor metastasis are reviewed in this publication using ovarian cancer, which exhibits high metastatic potential, as an example. Information and data on the genes and regulatory microRNAs involved in the formation of cancer stem cells, epithelial-mesenchymal transition, reducing focal adhesion, degradation of extracellular matrix, increasing migration activity of cancer cells, formation of spheroids, apoptosis, autophagy, angiogenesis, formation of metastases, and development of ascites are presented. Clusters of microRNAs (miR-145, miR-31, miR-506, miR-101) most essential for metastasis of ovarian cancer including the families of microRNAs (miR-200, miR-214, miR-25) with dual role, which is different in different histological types of ovarian cancer, are discussed in detail in a section of the review.

Diagnostic and therapeutic potentials of microRNAs in cholangiopathies

Cholangiopathies are a group of rare, devastating diseases that arise from damaged cholangiocytes, the cells that line the intra- and extra-hepatic bile ducts of the biliary epithelium. Cholangiopathies result in significant morbidity and mortality and are a major cause of liver transplantation. A better understanding of the underlying pathogenesis that influences cholangiocyte dysregulation and cholangiopathy progression is necessary, considering the dismal prognosis associated with these diseases. MicroRNAs are a class of small, non-coding RNAs that regulate post-transcriptional mRNA expression of specific genes. The role of microRNAs has expanded to include the initiation and development of many diseases, including cholangiopathies. Understanding microRNA regulation of cholangiopathies may provide diagnostic and therapeutic benefit for these diseases. In this review, the authors primarily focus on studies published within the last five years that help determine the diagnostic and therapeutic potential of microRNAs in cholangiopathies.

miR-489 acts as a tumor suppressor in human gastric cancer by targeting PROX1

Dysregulation of microRNAs (miRNAs) are linked to tumorigenesis and tumor progression. In this study, we examined the expression of miR-489 in gastric cancer tissues and cells. Loss- and gain-of-function experiments were done to determine the roles of miR-489 in gastric cancer cell proliferation and invasion. Bioinformatic prediction, luciferase reporter assays, and Western blot analysis were employed to identify the target gene(s) of miR-489. We found that miR-489 was significantly (P < 0.05) downregulated in human gastric cancer tissues and cell lines, compared to their non-malignant counterparts. Enforced expression of miR-489 significantly suppressed gastric cancer cell proliferation and invasion, while miR-489 knockdown enhanced the aggressive behaviors of gastric cancer cells. Prospero homeobox 1 (PROX1) was identified to be a direct target of miR-489. A significant negative correlation was seen between miR-489 and PROX1 protein expression in gastric cancer tissues (r = -0.462, P = 0.023). Silencing of PROX1 phenocopied the suppressive effects of miR-489 in gastric cancer cells. Rescue experiments demonstrated that overexpression of a miR-489-resistant form of PROX1 significantly prevented the reduction in cell proliferation and invasion induced by miR-489 overexpression. In vivo studies confirmed that miR-489 overexpression retarded the growth of xenograft tumors, which was accompanied by reduced PROX1 expression. Overall, these data provide evidence for the suppressive activity of miR-489 in gastric cancer, which is ascribed to targeting of PROX1. The miR-489/PROX1 axis may represent a potential therapeutic target for this disease.

miR-200c Regulation of Metastases in Ovarian Cancer: Potential Role in Epithelial and Mesenchymal Transition

Among the gynecological malignancies, ovarian cancer is the most fatal due to its high mortality rate. Most of the identified cases are epithelial ovarian cancer (EOC) with five distinct subtypes: high-grade serous carcinoma, low-grade serous carcinoma, mucinous carcinoma, endometrioid carcinoma, and clear-cell carcinoma. Lack of an early diagnostic approach, high incidence of tumor relapse and the heterogenous characteristics between each EOC subtypes contribute to the difficulties in developing precise intervention and therapy for the patients. MicroRNAs (miRNAs) are single-stranded RNAs that have been shown to function as tumor suppressors or oncomiRs. The miR-200 family, especially miR-200c, has been shown to be implicated in the metastasis and invasion of ovarian carcinoma due to its functional regulation of epithelial-to-mesenchymal transition (EMT). This mini review is aimed to summarize the recent findings of the miR-200c functional role as well as its validated targets in the metastasis cascade of ovarian cancer, with a focus on EMT regulation. The potential of this miRNA in early diagnosis and its dual expression status are also discussed.

miR-200c and phospho-AKT as prognostic factors and mediators of osteosarcoma progression and lung metastasis

Lung metastasis is the major cause of death in osteosarcoma patients. However, molecular mechanisms underlying this metastasis remain poorly understood. To identify key molecules related with pulmonary metastasis of pediatric osteosarcomas, we analyzed high-throughput miRNA expression in a cohort of 11 primary tumors and 15 lung metastases. Results were further validated with an independent cohort of 10 primary tumors and 6 metastases. In parallel, we performed immunohistochemical analysis of activated signaling pathways in 36 primary osteosarcomas. Only phospho-AKT associated with lower overall survival in primary tumors, supporting its role in osteosarcoma progression. CTNNB1 expression also associated with lower overall survival but was not strong enough to be considered an independent variable. Interestingly, miR-200c was overexpressed in lung metastases, implicating an inhibitory feed-back loop to PI3K-AKT. Moreover, transfection of miR200c-mimic in U2-OS cells reduced phospho-AKT levels but increased cellular migration and proliferation. Notably, miR-200c expression strongly correlated with miR-141 and with the osteogenic inhibitor miR-375, all implicated in epithelial to mesenchymal transition. These findings contrast epithelial tumors where reduced miR-200c expression promotes metastasis. Indeed, we noted that osteosarcoma cells in the lung also expressed the epithelial marker CDH1, revealing a change in their mesenchymal phenotype. We propose that miR-200c upregulation occurs late in osteosarcoma progression to provide cells with an epithelial phenotype that facilitates their integration in the metastatic lung niche. Thus, our findings identify phospho-AKT in the primary tumor and miR-200c later during tumor progression as prognostic molecules and potential therapeutic targets to prevent progression and metastasis of pediatric osteosarcomas.

Decreased expression of LncRNA MIR31HG in human bladder cancer

OBJECTIVE

In this study, we examined the relationships between the expression level of long non-coding RNA MIR31HG in bladder cancer and the clinical characteristics.

METHODS

A total of 55 tissue samples from patients with bladder cancer were collected, and the lncRNA MIR31HG levels in cancer, paired non-cancer tissues and BC cell lines were detected by real-time quantitative RT-PCR (qRT-PCR). The relationships between MIR31HG level and the clinical characteristics were evaluated.

RESULTS

MIR31HG expression was remarkably decreased in bladder cancer tissues compared with adjacent noncancerous tissues (P < 0.05). MIR31HG expression was also significantly down-regulated in four bladder cancer cell lines (P < 0.001). Clinicopathologic analysis revealed that MIR31HG expression was negatively associated with TNM stage (P = 0.010), but not with other clinicopathological characteristics.

CONCLUSIONS

These findings revealed that MIR31HG may function as a cancer-suppressor gene to participate in the bladder cancer carcinogenesis and development.

Characterization and identification of differentially expressed microRNAs during the process of the peribiliary fibrosis induced by Clonorchis sinensis

Clonorchis sinensis (C. sinensis) infection can lead to biliary fibrosis. MicroRNAs (miRNAs) play important roles in regulation of genes expression in the liver diseases. However, the differential expression of miRNAs that probably regulates the portal fibrogenesis caused by C. sinensis has not yet been investigated. Hepatic miRNAs expression profiles from C. sinensis-infected mice at different time-points were analyzed by miRNA microarray and validated by quantitative real-time PCR (qRT-PCR). 349 miRNAs were differentially expressed in the liver of the C. sinensis-infected mice at 2, 8 or 16weeks post infection (p.i.), compared with those at 0week p.i., and there were 143 down-regulated and 206 up-regulated miRNAs among them. These all dysregulated miRNAs were potentially involved in the pathological processes of clonorchiasis by regulation of cancer-related signaling pathway, TGF-β signaling pathway, MAPK signaling pathway, Toll-like receptor signaling pathway, PI3K /AKT signaling pathway, etc. 169 of these dysregulated miRNAs were predicted to be involved in the TGF/Smads signaling pathway which plays an important role in the biliary fibrosis caused by C. sinensis. Additionally, miRNA-32, miRNA-34a, miRNA-125b and miRNA-497 were negatively correlated with Smad7 expression, indicating these miRNAs may specifically down-regulate Smad7 expression and participate in regulation of biliary fibrosis caused by C. sinensis. The results of the present study for the first time demonstrated that miRNAs were differentially expressed in the liver of mice infected by C. sinensis, and these miRNAs may play important roles in regulation of peribiliary fibrosis caused by C. sinensis, which may provide possible therapeutic targets for clonorchiasis.

Genetic and epigenetic heterogeneity of epithelial ovarian cancer and the clinical implications for molecular targeted therapy

Epithelial ovarian cancer (EOC) is the most lethal gynaecological malignancy, and tumoural heterogeneity (TH) has been blamed for treatment failure. The genomic and epigenomic atlas of EOC varies significantly with tumour histotype, grade, stage, sensitivity to chemotherapy and prognosis. Rapidly accumulating knowledge about the genetic and epigenetic events that control TH in EOC has facilitated the development of molecular-targeted therapy. Poly (ADP-ribose) polymerase (PARP) inhibitors, designed to target homologous recombination, are poised to change how breast cancer susceptibility gene (BRCA)-related ovarian cancer is treated. Epigenetic treatment regimens being tested in clinical or preclinical studies could provide promising novel treatment approaches and hope for improving patient survival.

NRP1 is targeted by miR-130a and miR-130b, and is associated with multidrug resistance in epithelial ovarian cancer based on integrated gene network analysis

Multidrug resistance (MDR) in epithelial ovarian cancer (EOC) remains a public health issue for women worldwide, and its molecular mechanisms remain to be fully elucidated. The present study aimed to predict the potential genes involved in MDR, and examine the mechanisms underlying MDR in EOC using bioinformatics techniques. In the present study, four public microarray datasets, including GSE41499, GSE33482, GSE15372 and GSE28739, available in Gene Expression Omnibus were downloaded, and 11 microRNAs (miRNA; miRs), including miR-130a, miR-214, let-7i, miR-125b, miR-376c, miR-199a, miR-93, miR-141, miR-130b, miR-193b^* and miR-200c, from previously published reports in PubMed were used to perform a comprehensive bioinformatics analysis through gene expression analysis, signaling pathway analysis, literature co-occurrence and miRNA-mRNA interaction networks. The results demonstrated that the expression of neuropilin 1 (NRP1) was upregulated, thereby acting as the most important hub gene in the integrated gene network. NRP1 was targeted by miR-130a and miR-130b at the binding site of chromosome 10: 33466864-3466870, which was involved in the axon guidance signaling pathway. These results suggested that alteration of the gene expression levels of NRP1 expression may contribute to MDR in EOC. These data provide important information for further experimental investigations of the drug resistance-associated functions of NRP1 in EOC.

MicroRNA-17-5p induces drug resistance and invasion of ovarian carcinoma cells by targeting PTEN signaling

Background

The miR-17-5p was overexpressed in ovarian cancer cells, and those cells were treated with paclitaxel. The proliferation of ovarian cancer cells was assessed by MTT assay. The Caspase-Glo3/7 and TUNEL assay were used to examine the effect of miR-17-5p on paclitaxel-induced apoptosis in ovarian cancer cells. The migration and invasion of ovarian cancer cells were analyzed by BD matrigel assays. Western blot was performed to evaluate the expression of apoptotic proteins and epithelial-mesenchymal transition markers in ovarian cancer cells.

Results

The survival rate of ovarian cancer cells was increased after overexpression of miR-17-5p. The apoptosis decreased in miR-17-5p overexpressed ovarian cancer cells. Altered miR-17-5p expression affected migration and invasion of ovarian cancer cells. The overexpression of miR-17-5p altered the expression of EMT markers. miR-17-5p activates AKT by downregulation of PTEN in ovarian cancer cells.

Conclusion

Our results indicate that miR-17-5p might serve as potential molecular therapeutic target.