Upregulation of miR-183-5p is responsible for the promotion of apoptosis and inhibition of the epithelial-mesenchymal transition, proliferation, invasion and migration of human endometrial cancer cells by downregulating Ezrin

MicroRNA-183 cluster: a promising biomarker and therapeutic target in gastrointestinal malignancies

Small non-coding RNAs (microRNA, miR), powerful epigenetic regulators, were found involved in the regulation of most biological functions via post-translational inhibition of protein expression. Increased expression of pro-oncogenic miRs (known as miR cancer biomarkers) and inhibition of pro-apoptotic miR expression have been demonstrated in different tumors. The recently identified miR-183 was found implicated in gastrointestinal tumor metabolism regulation. Elevated miR-183 expression and cancer-promoting effects were reported in esophageal and colorectal cancers, which was partially contradicted by controversial data observed in gastric cancers. Anti-cancer effect of miR-183 in gastric cancer cells was associated with the Bim-1 and Ezrin genes regulation. Many studies indicated that miR-183 can inhibit tumor suppressor genes in most cell lines, promoting tumor cell proliferation and migration. Increased miR-183 level results in the downregulation of FOXO1, PDCD4, and other tumor suppressor genes in gastrointestinal tumor cells. MiR-183 also influences the signaling of PI3K/AKT/mTOR, Wnt/β-catenin, and Bcl-2/p53 signaling pathways. Mir-183 inhibits apoptosis and autophagy, and promotes epithelial-to-mesenchymal transition, cancer cell proliferation, and migration. Accordingly, gastrointestinal cancer occurrence, development of chemoradiotherapy resistance, recurrence/metastasis, and prognosis were associated with miR-183 expression. The current study assessed reported miR-183 functions and signaling, providing new insights for the diagnosis and treatment of gastrointestinal malignancies.

eIF2Bδ blocks the integrated stress response and maintains eIF2B activity and cancer metastasis by overexpression in breast cancer stem cells

Breast cancer (BC) metastasis involves cancer stem cells (CSCs) and their regulation by micro-RNAs (miRs), but miR targeting of the translation machinery in CSCs is poorly explored. We therefore screened miR expression levels in a range of BC cell lines, comparing non-CSCs to CSCs, and focused on miRs that target translation and protein synthesis factors. We describe a unique translation regulatory axis enacted by reduced expression of miR-183 in breast CSCs, which we show targets the eIF2Bδ subunit of guanine nucleotide exchange factor eIF2B, a regulator of protein synthesis and the integrated stress response (ISR) pathway. We report that reduced expression of miR-183 greatly increases eIF2Bδ protein levels, preventing strong induction of the ISR and eIF2α phosphorylation, by preferential interaction with P-eIF2α. eIF2Bδ overexpression is essential for BC cell invasion, metastasis, maintenance of metastases, and breast CSC expansion in animal models. Increased expression of eIF2Bδ, a site of action of the drug ISRIB that also prevents ISR signaling, is essential for breast CSC maintenance and metastatic capacity.

Ezrin expression in female reproductive tissues: A review of regulation and pathophysiological implications

Ezrin, a plasma membrane-microfilament linker, is a cytoskeletal organizer involved in many cellular activities by binding to the membrane protein-ezrin-cytoskeletal protein complex and regulating downstream signal transduction. Increasing evidence demonstrates that ezrin plays an important role in regulating cell polarity, proliferation and invasion. In this study, we analyzed the effects of ezrin on oocytes, follicle development, embryo development and embryo implantation. We reviewed the recent studies on the modalities of ezrin regulation and its involvement in the biological processes of female reproductive physiology and summarized the current research advances in ezrin inhibitors. These studies will provide new strategies and insights for the treatment of diseases.

The Role of MicroRNA in the Regulation of Tumor Epithelial–Mesenchymal Transition

Consistently, the high metastasis of cancer cells is the bottleneck in the process of tumor treatment. In this process of metastasis, a pivotal role is executed by epithelial–mesenchymal transition (EMT). The epithelial-to-mesenchymal transformation was first proposed to occur during embryonic development. Later, its important role in explaining embryonic developmental processes was widely reported. Recently, EMT and its intermediate state were also identified as crucial drivers in tumor progression with the gradual deepening of research. To gain insights into the potential mechanism, increasing attention has been focused on the EMT-related transcription factors. Correspondingly, miRNAs target transcription factors to control the EMT process of tumor cells in different types of cancers, while there are still many exciting and challenging questions about the phenomenon of microRNA regulation of cancer EMT. We describe the relevant mechanisms of miRNAs regulating EMT, and trace the regulatory roles and functions of major EMT-related transcription factors, including Snail, Twist, zinc finger E-box-binding homeobox (ZEB), and other families. In addition, on the basis of the complex regulatory network, we hope that the exploration of the regulatory relationship of non-transcription factors will provide a better understanding of EMT and cancer metastasis. The identification of the mechanism leading to the activation of EMT programs during diverse disease processes also provides a new protocol for the plasticity of distinct cellular phenotypes and possible therapeutic interventions. Here, we summarize the recent progress in this direction, with a promising path for further insight into this fast-moving field.

Ezrin Regulates the Cell Surface Localization of PD-L1 in HEC-151 Cells

Programmed death ligand-1 (PD-L1) is an immune checkpoint molecule widely expressed on the surface of cancer cells and is an attractive immunotherapeutic target for numerous cancer cell types. However, patients with endometrial cancer derive little clinical benefit from immune checkpoint blockade therapy because of their poor response rate. Despite the increasingly important function of PD-L1 in tumor immunology, the mechanism of PD-L1 localization on endometrial cancer cell surfaces is largely unknown. We demonstrated the contribution of the ezrin, radixin, and moesin (ERM) family, which consists of scaffold proteins that control the cell surface localization of several transmembrane proteins to the localization of PD-L1 on the cell surface of HEC-151, a human uterine endometrial cancer cell line. Confocal immunofluorescence microscopy and immunoprecipitation analysis revealed the colocalization of all the ERM with PD-L1 on the cell surface, as well as their protein–protein interactions. The RNA-interference-mediated knockdown of ezrin, but not radixin and moesin, significantly reduced the cell surface expression of PD-L1, as measured by flow cytometry, with little impact on the PD-L1 mRNA expression. In conclusion, among the three ERM proteins present in HEC-151 cells, ezrin may execute the scaffold function for PD-L1 and may be mainly responsible for the cell surface localization of PD-L1, presumably via the post-translational modification process.

MicroRNAs and Heat Shock Proteins in Breast Cancer Biology

Breast cancer has five major immune types; luminal A, luminal B, HER2, Basal-like, and normal-like. Cells produce a family of protein called heat shock proteins (Hsps) in response to exposure to thermal and other proteotoxic stresses play essential roles in cancer metabolism and this large family shows a diverse set of Hsp involvement in different breast cancer immune types. Recently, Hsp members categorized according to their immune type roles. Hsp family consists of several subtypes formed by molecular weight; Hsp70, Hsp90, Hsp100, Hsp40, Hsp60, and small molecule Hsps. Cancer cells employ Hsps as survival factors since most of these proteins prevent apoptosis. Several studies monitored Hsp roles in breast cancer cells and reported Hsp27 involvement in drug resistance, Hsp70 in tumor cell transformation-progression, and interaction with p53. Furthermore, the association of Hsp90 with steroid receptors and signaling proteins in patients with breast cancer directed research to focus on Hsp-based treatments. miRNAs are known to play key roles in all types of cancer that are upregulated or downregulated in cancer which respectively referred to as oncogenes (oncomirs) or tumor suppressors. Expression profiles of miRNAs may be used to classify, diagnose, and predict different cancer types. It is clear that miRNAs play regulatory roles in gene expression and this work reveals miRNA correlation to Hsp depending on specific breast cancer immune types. Deregulation of specific Hsp genes in breast cancer subtypes allows for identification of new targets for drug design and cancer treatment. Here, we performed miRNA network analysis by recruiting Hsp genes detected in breast cancer subtypes and reviewed some of the miRNAs related to aforementioned Hsp genes.

circCDYL2, Overexpressed in Highly Migratory Colorectal Cancer Cells, Promotes Migration by Binding to Ezrin

Background

Colorectal cancer (CRC) is one of the most common malignancies with high mortality worldwide, particularly due to metastasis. However, there are no clinically available strategies for treating CRC metastasis. Exploring the mechanisms underlying CRC metastasis is the key to improve the treatment of CRC with metastasis.

Methods

In this study, we generated the highly migratory CRC cell subline H-RKO using a repeated transwell migration assay to identify circRNAs involved in CRC migration by high-throughput RNA sequencing. Upregulated circRNAs were validated by RT-qPCR to identify the most elevated circRNA. The expression of this circRNA (circCDYL2) was evaluated in 40 pairs of CRC tissues and four CRC cell lines by RT-qPCR. Transwell migration and wound healing assays were performed to verify the function of circCDYL2 in cell migration. The cellular distribution of circCDYL2 was confirmed using PCR. RNA pulldown and RNA immunoprecipitation were used to confirm the interaction between circCDYL2 and Ezrin. Western blotting, immunohistochemistry, and rescue experiments were used to determine the role of circCDYL2 in regulating Ezrin protein expression and AKT phosphorylation.

Results

Among the candidate circRNAs, circCDYL2 was the highest overexpressed circRNA in H-RKO compared to parental N-RKO cells. Furthermore, circCDYL2 expression was elevated in CRC tissues and cell lines. Gain- and loss-of-function assays indicated that circCDYL2 enhanced the migration of CRC cells. circCDYL2 was located in the cytoplasm of CRC cells and interacted with Ezrin to upregulate its protein levels, resulting in AKT phosphorylation. Ezrin knockdown abrogated the CRC cell migration induced by circCDYL2 overexpression.

Conclusions

Our study demonstrated for the first time that circCDYL2 promotes CRC migration by binding Ezrin and activating the AKT pathway. CircCDYL2 represents a potential therapeutic target for preventing CRC metastasis.

Identification of a novel circ_0018289/miR-183-5p/TMED5 regulatory network in cervical cancer development

Background

Circular RNAs (circRNAs) are increasingly implicated in regulating human carcinogenesis. Previous work showed the oncogenic activity of circ_0018289 in cervical cancer. However, the molecular basis underlying the modulation of circ_0018289 in cervical carcinogenesis is still not fully understood.

Methods

The levels of circ_0018289, microRNA (miR)-183-5p, and transmembrane p24 trafficking protein 5 (TMED5) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay. Ribonuclease (RNase) R and subcellular localization assays were used to characterize circ_0018289. Cell proliferation was detected by the Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2′-deoxyuridine (Edu) assays. Cell apoptosis and tube formation were assessed by flow cytometry and tube formation assays, respectively. A dual-luciferase reporter assay was performed to confirm the direct relationship between miR-183-5p and circ_0018289 or TMED5. The role of circ_0018289 in tumor growth was gauged by mouse xenograft experiments.

Results

Circ_0018289 was overexpressed in cervical cancer tissues and cells. Circ_0018289 silencing impeded cell proliferation, enhanced cell apoptosis, and suppressed angiogenesis in vitro, as well as diminished tumor growth in vivo. Mechanistically, circ_0018289 targeted and regulated miR-183-5p by binding to miR-183-5p, and circ_0018289 regulated cervical cancer development and angiogenesis partially through miR-183-5p. Moreover, TMED5 was directly targeted and inhibited by miR-183-5p through the perfect complementary sites in TMED5 3′UTR, and TMED5 knockdown phenocopied miR-183-5p overexpression in suppressing cervical cancer development and angiogenesis. Furthermore, circ_0018289 induced TMED5 expression by competitively binding to shared miR-183-5p.

Conclusion

Our observations identified the circ_0018289/miR-183-5p/TMED5 regulatory network as a novel molecular basis underlying the modulation of cervical carcinogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02350-y.

NEAT1 Negatively Regulates Cell Proliferation and Migration of Neuroblastoma Cells by miR-183-5p/FOXP1 Via the ERK/AKT Pathway

Neuroblastoma, a malignant tumor of the sympathetic nervous system, is an aggressive extracranial tumor in childhood. Long noncoding RNAs (lncRNAs) have been discovered to play a key role in the eukaryotic regulatory gene network and be involved in a wide variety of biological processes. We observed that the expression of lncRNA nuclear-enriched abundant transcript-1 (NEAT1) was significantly decreased in human neuroblastoma tissues and cell lines, compared with the normal. We observed cell proliferation, migration, and invasion with Cell Counting Kit-8 assay, colony formation assay, and Transwell assay to investigate the effects of NEAT1, miR-183-5p, or FOXP1 on neuroblastoma cells. And we also used StarBase and luciferase reporter gene assay to predict and confirm the interaction of NEAT1, miR-183-5p, and FOXP1 in neuroblastoma cells. First, overexpression of NEAT1 suppressed cell proliferation and played a key role in cell migration and invasion. In addition, NEAT1 was demonstrated to directly interact with miR-183-5p and exerted its antioncogenic role in neuroblastoma by negatively regulating miR-183-5p expression. miR-183-5p suppressed the expression of FOXP1 and regulated cell proliferation and migration by directly targeting FOXP1 mRNA 3′-untranslated region. Moreover, FOXP1 antagonized the effect of miR-183-5p on the phosphorylation of extracellular-regulated kinase/protein kinase B (ERK/AKT), while FOXP1 siRNA increased the reduced phosphorylation of ERK/AKT caused by miR-183-5p inhibitor in neuroblastoma cells. Taken together, these data showed that NEAT1 negatively regulated cell proliferation and migration of neuroblastoma by the miR-183-5p/FOXP1 axis via suppression of the ERK/AKT pathway. Our findings may provide a new target for the study of pathogenesis and treatment of neuroblastoma.

The Role of miRNAs in the Regulation of Endometrial Cancer Invasiveness and Metastasis-A Systematic Review

Endometrial cancer (EC) is the most common genital cancer in women with increasing death rates. MiRNAs are short non-coding RNAs that regulate gene expression on the post-transcriptional levels. Multiple studies demonstrated a fundamental role of miRNAs in the regulation of carcinogenesis. This systematic review is a comprehensive overview of the role of miRNAs in the regulation of cancer cell invasiveness and metastasis in EC. The literature was searched for studies investigating the role of miRNAs in the regulation of invasiveness and metastasis in EC. We explored PubMed, Embase, and Scopus using the following keywords: miRNA, metastasis, invasiveness, endometrial cancer. Data were collected from 163 articles that described the expression and role of 106 miRNAs in the regulation of EC invasiveness and metastasis out of which 63 were tumor suppressor miRNAs, and 38 were oncomiRNAs. Five miRNAs had a discordant role in different studies. Moreover, we identified 66 miRNAs whose expression in tumor tissue or concentration in serum correlated with at least one clinical parameter. These findings suggest a crucial role of miRNAs in the regulation of EC invasiveness and metastasis and present them as potential prognostic factors for patients with EC.

miR-15b-3p promotes the malignant progression of endometrial cancer cells through targeting KLF2

Human endometrial cancer is one of the most common malignant tumors in women with an increased incidence by years. The biological function of miR-15b-3p in endometrial cancer is still unclear. Therefore, this study explores the expression and potential mechanism of miR-15b-3p in endometrial cancer, providing a novel theory basis for targeted therapy. Herein, differentially expressed miRNAs and mRNAs in endometrial cancer were determined by bioinformatics analysis. qRT-PCR measured expression of miRNAs and mRNAs. The protein expression of mRNA in cells was determined by western blot. MTT, wound healing, and Transwell assays evaluated the biological behavior of cells. Dual luciferase assay validated the targeted relationship between target miRNA and mRNA. miR-15b-3p was highly expressed in endometrial cancer, and overexpression of miR-15b-3p promoted the malignant progression of endometrial cancer cells. KLF2 was a downstream target of miR-15b-3p, and overexpression of KLF2 reversed the facilitation of miR-15b-3p on endometrial cancer cells. miR-15b-3p promoted the proliferation, migration, and invasion of endometrial cancer cells by targeting KLF2, which made miR-15b-3p a potential diagnostic factor and new molecular therapeutic target for endometrial cancer.

Non-Coding RNAs as Prognostic Markers for Endometrial Cancer

Endometrial cancer (EC) has been classified over the years, for prognostic and therapeutic purposes. In recent years, classification systems have been emerging not only based on EC clinical and pathological characteristics but also on its genetic and epigenetic features. Noncoding RNAs (ncRNAs) are emerging as promising markers in several cancer types, including EC, for which their prognostic value is currently under investigation and will likely integrate the present prognostic tools based on protein coding genes. This review aims to underline the importance of the genetic and epigenetic events in the EC tumorigenesis, by expounding upon the prognostic role of ncRNAs.

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.

MiR-183-5p Promotes Tumor Progression of Osteosarcoma and Predicts Poor Prognosis in Patients

Background

Although miRNA-183-5p plays a critical role in many cancer types, including gastric cancer, hepatocellular carcinoma, prostate cancer, renal cell cancer and breast cancer, its role in osteosarcoma remains unclear.

Methods

Expression levels of miR-183-5p were detected in osteosarcoma tissues and cell lines using qRT-PCR. The effect of miR-183-5p on the survival and recurrence of osteosarcoma patients was analyzed in a cohort of 80 patients using Kaplan-Meier curves and Cox regression analysis. Effects of miR-183-5p on cell proliferation, migration and invasion abilities were evaluated using CCK-8, crystal violet and transwell assays.

Results

The expression of miR-183-5p was found to be upregulated in human osteosarcoma tissues and cell lines. Moreover, miR-183-5p expression was observed to be closely associated with tumor size, TNM stage and lung metastasis. Notably, high expression of miR-183-5p was shown to be able to predict unfavorable clinical prognosis in osteosarcoma patients. Additionally, whilst overexpression of miR-183-5p was observed to significantly promote the proliferation, migration and invasion of osteosarcoma cells; an inhibitory effect was observed with knockdown of miR-183-5p.

Conclusion

This study demonstrated that miR-183-5p acts as an oncogene and plays a critical role in the regulation of osteosarcoma tumor progression, and our results suggest a novel potential prognostic and therapeutic value of miR-183-5p in osteosarcoma.

Silenced lncRNA H19 and up-regulated microRNA-129 accelerates viability and restrains apoptosis of PC12 cells induced by Aβ25-35 in a cellular model of Alzheimer's disease

Accumulating data manifest that long non-coding RNA (lncRNAs) are involved in all kinds of neurodegenerative disorders, consisting of the onset and progression of Alzheimer's disease (AD). The study was for the research of the mechanism of lncRNA H19 (H19) in viability and apoptosis of PC12 cells induced by Aβ_25-35 in a cellular model of AD with the regulation of microRNA (miR)-129 and high mobility group box-1 protein (HMGB1). An AD cellular model of PC12 cells was established using Aβ_25-35. The Aβ_25-35-induced PC12 cells were transfected with si-H19 or miR-129 mimic to figure their roles in cell viability,apoptosis, mitochondrial membrane potential dysfunction and oxidative stress in AD. Luciferase reporter assay and RNA-pull down assay were employed for verification of the binding relationship between H19 and miR-129 and the targeting relationship between miR-129 and HMGB1. An AD mouse model was induced and brain tissues were collected. H19, miR-129 and HMGB1 were detected in Aβ_25-35-treated cells and brain tissues of AD mice. Elevated H19, HMGB1 and decreased miR-129 were found in Aβ_25-35-treated PC12 cells as well as in brain tissues of AD mice. Silenced H19 or elevated miR-129 promoted viability, inhibited apoptosis, prevented mitochondrial membrane potential dysfunction and decreased oxidative stress in Aβ_25-35-treated PC12 cells. H19 could specifically bind to miR-129. MiR-129 specifically suppressed HMGB1 expression. This study suggests that silenced H19 and up-regulated miR-129 accelerates viability and represses apoptosis of PC12 cells stimulated by Aβ_25-35 in AD, which is beneficial for AD treatment.

Exosomal miR-499a-5p Inhibits Endometrial Cancer Growth and Metastasis via Targeting VAV3

Background/Aim

The current therapeutic strategies for endometrial cancer are limited and unsatisfactory. Accumulating evidence suggest that microRNAs (miRNAs) participate in tumor growth and metastasis. Mesenchymal stem cells (MSCs) derived exosomes (Exos) are considered as better miRNA delivery vehicles. Here, we investigated the therapeutic effect of exosomal miR-499a-5p (miR-499) in human endometrial cancer metastasis.

Methods

Microarray analysis and RT-PCR were performed to detect the relative expression of miR-499 in endometrial cancer tissues and cell lines. MSC-derived Exos were characterized by transmission electron microscope (TEM), Western blot (WB), and nanoparticle tracking analysis (NTA). miR-499 was loading into Exos using electroporation. Cell proliferation and angiogenesis capacity were tested by 5-ethynyl-29-deoxyuridine (EdU) assay and tube formation assay, respectively. Dual-luciferase reporter assay (DLR) was used to confirm the connection of miR-499 and VAV3.

Results

We found that the expression of miR-499 was significantly downregulated in cancer tissues compared with adjacent tissues in endometrial cancer patients. Moreover, exosomal miR-499 not only dramatically suppressed endometrial cancer cells proliferation, endothelial cells tube formation in vitro, but also inhibited tumor growth and angiogenesis in vivo. In addition, we confirmed that miR-499 directly targets the 3'UTR sequence of VAV3.

Conclusion

The novel identified exosomal miR-499 functions as a tumor suppressor in endometrial cancer though regulating VAV3, and these findings could be a valid molecular target for endometrial cancer therapy.

LncRNA SNHG16 Regulates the Progress of Acute Myeloid Leukemia Through miR183-5p-FOXO1 Axis

Purpose

At present, there is a lack of precise knowledge on acute myeloid leukemia (AML) at the molecular level, and understanding its occurrence at the genetic level is conducive to the development of targeted therapies. Therefore, in this study the relationship between the lncRNA SNHG1 –miR183-5p–FOXO1 axis and AML was explored.

Methods

Expression of lncRNA SNHG16 and miR183-5p was quantified by quantitative real-time PCR, and the level of FOXO1 and other proteins was measured by Western blot. Expression vectors of lncRNA SNHG16, miR183-5p, and FOXO1 were constructed to assess effects of the three on cell proliferation and apoptosis. MTT reduction assays were employed for cell proliferation, flow cytometry for cell cycle and apoptosis, and dual luciferase–reporter assays for the targeting relationship between lncRNA SNHG16 and miR183-5p and miR183-5p and FOXO1.

Results

lncRNA SNHG16 was highly expressed in peripheral blood/leukemia cell lines of patients with AML compared with normal human peripheral blood/peripheral blood mononuclear cells. miR183-5p was the target of lncRNA SNHG16 and FOXO1 the target gene of miR183-5p rather than lncRNA SNHG16. Absence of lncRNA SNHG16 led to upregulation of miR183-5p, promotion of apoptosis, and inhibition of proliferation. Suppression of miR183-5p accelerated cell proliferation and hindered apoptosis. miR183-5p negatively regulated FOXO1, and FOXO1 promoted proliferation and inhibited apoptosis. Inhibition of miR183-5p counteracted the changes caused by lncRNA SNHG16 absence.

Conclusion

lncRNA SNHG16 regulates the progress of AML via the miR183-5p–FOXO1 axis.

MiR-183-5p Promotes Proliferation, Metastasis and Angiogenesis in Breast Cancer Cells through Negatively Regulating Four and a Half LIM Protein 1

Purpose

Four and a half LIM protein 1 (FHL1) is involved in breast cancer (BC) development, but the regulatory mechanism involved remain unclear. In the present study, we examined the role of FHL1 in BC development.

Methods

The expression of FHL1, miR-183-5p, and miR-96-5p in BC tissues was analyzed using StarBase analysis. FHL1 expression in BC tissues, a normal human breast epithelial cell line, and BC cell lines was detected using quantitative reverse transcription polymerase chain reaction (qRT-PCR). The relationship between FHL1 and miR-183-5p/miR-96-5p was analyzed via Pearson's rank correlation, TargetScan, and a dual-luciferase reporter assay. BT549 and MDA-MB-231 cells were transfected with either FHL1 and miR-183-5p mimics, or siFHL1 and a miR-183-5p inhibitor, respectively. The viability, colony number, migration, invasion, and tube length of BT549 and MDA-MB-231 cells were examined using cell counting kit-8, colony formation, wound-healing, Transwell, and tube formation assays, respectively. The levels of FHL1, vascular endothelial growth factor (VEGF), p53, E-cadherin, N-cadherin, and vimentin were quantified using western blotting and qRT-PCR.

Results

FHL1 expression was downregulated in BC tissues and cells, whereas miR-183-5p and miR-96-5p were upregulated in BC tissues (negative correlation with FHL1 expression). FHL1 overexpression inhibited the viability, colony number, migration, and invasion of BC cells and the expression of VEGF, N-cadherin, and vimentin, and increased the expression of FHL1, p53, and E-cadherin in BT549 cells. Furthermore, a miR-183-5p mimic reversed these effects of FHL1 overexpression, whereas FHL1 silencing caused opposite results to those observed in MDA-MB-231 cells; however, this was reversed by a miR-183-5p inhibitor.

Conclusion

Our study suggests that miR-183-5p promotes cell proliferation, metastasis, and angiogenesis by negatively regulating FHL1 in BC.

The Interplay of Tumor Stroma and Translational Factors in Endometrial Cancer

Endometrial cancer (EC) is a common gynecologic malignancy which continues to have a poor prognosis in advanced stages due to current therapeutic limitations. A significant mechanism of chemoresistance in EC has been shown to also be the enhancement of epithelial to mesenchymal transition (EMT) and the subsequent obtainment of stem cell-like characteristics of EC. Current evidence on EMT in EC however fails to explain the relationship leading to an EMT signaling enhancement. Our review therefore focuses on understanding eukaryotic translation initiation factors (eIFs) as key regulators of the translational process in enhancing EMT and subsequently impacting higher chemoresistance of EC. We identified pathways connected to the development of a microenvironment for EMT, inducers of the process specifically related to estrogen receptors as well as their interplay with eIFs. In the future, investigation elucidating the translational biology of EC in EMT may therefore focus on the signaling between protein kinase RNA-like ER kinase (PERK) and eIF2alpha as well as eIF3B.

Elevation in the Expression of circ_0079586 Predicts Poor Prognosis and Accelerates Progression in Glioma via Interactions with the miR-183-5p/MDM4 Signaling Pathway

Purpose

Glioma (GM) usually presents with an aggressive behavior and has a poor survival outcome. The abnormal expression of circular RNAs (circRNAs) has already been detected in GM, and circ_0079586 was found to have an increased expression in GM tumors.

Patients and Methods

We assessed the differences in the expression of circ_0079586 in GM tissues (N=60) and cell lines (N=5) using qRT-PCR. The clinical value of circ_0079586 was measured by Fisher’s exact test and Kaplan–Meier and Cox regression analyses. Circ_0079586 siRNA and vector were transfected into LN229 and U251 cells, respectively, and the transfection was verified by qRT-PCR. Cell growth was evaluated by cell counting kit-8 (CCK-8). Cell apoptosis was measured using flow cytometric assay. Cell metastatic properties were measured by wound scratch and transwell experiments. Subcellular fractionation was used to identify the location of circ_0079586. Dual-luciferase reporter test was utilized to confirm the interaction between miR-183-5p and circ_0079586/MDM4 3ʹ-UTR.

Results

The expression of circ_0079586 was elevated in GM samples and cells and correlated with the clinical severity and unfavorable prognosis of the patients. The elevated expression of circ_0079586 led to an increase in cell growth, migration and invasion but inhibited apoptosis in U251 cells, whereas its down-regulation reversed these effects in the LN229 cells. Mechanistically, we found circ_0079586 to be primarily located in the cytoplasm of GM cells. Furthermore, circ_0079586 could act as a sponge for miR-183-5p and elevate MDM4 expression at the posttranscriptional level.

Conclusion

In summary, circ_0079586 was found to be up-regulated in GM that increased the proliferation, migration and invasion in GM cells via interaction with the miR-183-5p/MDM4 axis. We anticipate that our study would provide newer insights into the mechanism and treatment of GM.

Novel miRNA markers for the diagnosis and prognosis of endometrial cancer

As endometrial cancer (EC) is a major threat to female health worldwide, the ability to provide an accurate diagnosis and prognosis of EC is promising to improve its treatment guidance. Since the discovery of miRNAs, it has been realized that miRNAs are associated with every cell function, including malignant transformation and metastasis. This study aimed to explore diagnostic and prognostic miRNA markers of EC. In this study, differential analysis and machine learning were performed, followed by correlation analysis of miRNA-mRNA based on the miRNA and mRNA expression data. Nine miRNAs were identified as diagnostic markers, and a diagnostic classifier was established to distinguish between EC and normal endometrium tissue with overall correct rates >95%. Five specific prognostic miRNA markers were selected to construct a prognostic model, which was confirmed more effective in identifying EC patients at high risk of mortality compared with the FIGO staging system. This study demonstrates that the expression patterns of miRNAs may hold promise for becoming diagnostic and prognostic biomarkers and novel therapeutic targets for EC.

Regulations of miR-183-5p and Snail-Mediated Shikonin-Reduced Epithelial-Mesenchymal Transition in Cervical Cancer Cells

Background

Shikonin, the main ingredient of Lithospermum erythrorhizon, has been reported to have antitumor effects via multiple targets and signaling pathways. However, the detailed mechanism underlying the effects in cervical cancer still remained unknown.

Methods

MTT, wound-healing, transwell assays and flow cytometry experiments were used to measure cell growth, migration, invasion, and cell cycle analysis. Western blot was used to examine protein levels of Snail, Vimentin and E-cadherin. The expression level of miR-183-5p was measured via qRT-PCR. The E-cadherin promoter activity was detected via Secrete-PairTM Dual Luminescence Assay Kit. The transient transfection experiments were used for silencing of E-cadherin and overexpression of Snail genes. Tumor xenograft and bioluminescent imaging experiments were carried out to confirm the in vitro findings.

Results

We showed that shikonin inhibited cell viability, migration and invasion, and induced cell cycle arrest in a dose-dependent manner in cervical cancer Hela and C33a cells. Mechanistically, we found that shikonin increased miR-183-5p expression and inhibited expression of transcription factor Snail protein. The mimics of miR-183-5p reduced, while the inhibitors of miR-183-5p reversed shikonin-inhibited Snail protein expression. In addition, shikonin decreased Vimentin, increased E-cadherin protein expressions and E-cadherin promoter activity, the latter was reversed in cells transfected with exogenous Snail overexpression vectors. Moreover, silencing of E-cadherin significantly abolished shikonin-inhibited cervical cancer cell growth. Similar findings were also observed in vivo using one xenograft mouse model.

Conclusion

Our results show that shikonin inhibits EMT through inhibition of Snail and stimulation of miR-183-5p expressions, which resulted in induction of E-cadherin expression. Thus, blockade of EMT could be a novel mechanism underlying the anti-cervical cancer effects of shikonin.

MicroRNA-183 in Cancer Progression

MicroRNA-183(miR-183) is abnormally expressed in many kinds of tumors. It participates in the initiation and development of tumors. There are many pathways regulate the expression of miR-183. The action mechanism of miR-183 in cancer is very extensive, and contradictory conclusions are often drawn. It was upregulated in 18 kinds of cancer, downregulated in 6 kinds of cancer. In addition, there are seven types of cancer, both upregulated and downregulated reports can be found. Evidence showed that miR-183 can not only directly play the role of oncogene or antioncogene, but also regulate the expression of other oncogene or antioncogene in different cancer types. In this review, we discuss the regulator of miR-183 and summarized the expression of miR-183 in different cancers. We also counted the target genes of miR-183 and the functional roles they play. Furthermore, we focused on the roles of miR-183 in cell migration, cell invasion, epithelial-mesenchymal transition (EMT) and microangiogenesis, which play the most important roles in cancer processes. It sheds light on the likely reasons why miR-183 plays different roles in various cancers. In addition, miR-183 and its downstream effectors have the potential to be promising prognostic markers and therapeutic targets in cancer.

Downregulated Circular RNA hsa_circ_0000291 Suppresses Migration And Proliferation Of Gastric Cancer Via Targeting The miR-183/ITGB1 Axis

Background

Circular RNAs are implicated in a variety of cancers. This investigation found that hsa_circ_0000291 expression was upregulated in gastric cancer (GC) cell lines, yet its role in GC has not yet been reported.

Objective

To explore the effects of hsa_circ_0000291 on GC cell proliferation and invasion.

Materials and methods

In the current research, we used the gastric cancer cell lines MGC803 and MKN-28 to study hsa_circ_0000291 function. The relationship between hsa_circ_0000291, miR-183 and ITGB1 was analyzed by firefly luciferase analysis and Western blots, and qRT-PCR approaches were used for protein and gene expression analysis, respectively. Tumor growth and metastasis were determined in nude mice xenografts using MKN-28 cells, with or without hsa_circ_000r0291 downregulation.

Results

Our data showed that hsa_circ_0000291 was upregulated in GC cell lines, whereas hsa_circ_0000291 silencing suppressed cell metastasis and proliferation in in vivo and in vitro studies. Our results showed that the downregulation of hsa_circ_0000291 suppressed integrin beta 1 (ITGB1) expression via miR-183 “sponging,” which was validated by rescue experiments using the luciferase reporter assay. Our observations suggested that hsa_circ_0000291 silencing suppressed the aggressive, metastatic GC phenotype.

Conclusion

Taken together, hsa_circ_0000291 knockdown inhibited GC cell metastasis and growth by regulating the miR-183/ITGB1 axis. Importantly, this approach could provide a therapy target and potential biomarker for the diagnosis and treatment of GC.

Network vulnerability-based and knowledge-guided identification of microRNA biomarkers indicating platinum resistance in high-grade serous ovarian cancer

Background

High-grade serous ovarian cancer (HGSC), the most common ovarian carcinoma type, is associated with the highest mortality rate among all gynecological malignancies. As chemoresistance has been demonstrated as the major challenge in improving the prognosis of HGSC patients, we here aimed to identify microRNA (miRNA) biomarkers for predicting platinum resistance and further explore their functions in HGSC.

Results

We developed and applied our network vulnerability-based and knowledge-guided bioinformatics model first time for the study of drug-resistance in cancer. Four miRNA biomarkers (miR-454-3p, miR-98-5p, miR-183-5p and miR-22-3p) were identified with potential in stratifying platinum-sensitive and platinum-resistant HGSC patients and predicting prognostic outcome. Among them, miR-454-3p and miR-183-5p were newly discovered to be closely implicated in platinum resistance in HGSC. Functional analyses highlighted crucial roles of the four miRNA biomarkers in platinum resistance through mediating transcriptional regulation, cell proliferation and apoptosis. Moreover, expression patterns of the miRNA biomarkers were validated in both platinum-sensitive and platinum-resistant ovarian cancer cells.

Conclusions

With bioinformatics modeling and analysis, we identified and confirmed four novel putative miRNA biomarkers, miR-454-3p, miR-98-5p, miR-183-5p and miR-22-3p that could serve as indicators of resistance to platinum-based chemotherapy, thereby contributing to the improvement of chemotherapeutic efficiency and optimization of personalized treatments in HGSC.

The Use of microRNAs in the Management of Endometrial Cancer: A Meta-Analysis

Introduction: Endometrial cancer (EC) is the most important gynecological cancer in terms of incidence. microRNAs (miRs), which are post-transcriptional regulators implicated in a variety of cellular functions including carcinogenesis, are particularly attractive candidates as biomarkers. Indeed, several studies have shown that the miR expression pattern appears to be associated with prognostic factors in EC. Our objective is to review the current knowledge of the role of miRs in carcinogenesis and tumor progression and their association with the prognosis of endometrial cancer. Materials and Method: We performed a literature search for miR expression in EC using MEDLINE, PubMed (the Internet portal of the National Library of Medicine) and The Cochrane Library, Cochrane databases “Cochrane Reviews” and “Clinical Trials” using the following keywords: microRNA, endometrial cancer, prognosis, diagnosis, lymph node, survival, plasma, FFPE (formalin-fixed, paraffin-embedded). The miRs were classified and presented according to their expression levels in cancer tissue in relation to different prognostic factors. Results: Data were collected from 74 original articles and 8 literature reviews which described the expression levels of 261 miRs in ECs, including 133 onco-miRs, 110 miR onco-suppressors, and 18 miRs with discordant functions. The review identified 30 articles studying the expression pattern of miR in neoplastic endometrial tissue compared to benign and/or hyperplastic tissues, 12 articles detailing the expression profile of miRs as a function of lymph node status, and 14 articles that detailed the expression pattern of miRs in endometrial tumor tissue according to overall survival or in the absence of recurrence. Conclusions: The findings presented here suggest that miR analysis merits a role as a prognostic factor in the management of patients with endometrial cancer.

MicroRNA-183 inhibition exerts suppressive effects on diabetic retinopathy by inactivating BTG1-mediated PI3K/Akt/VEGF signaling pathway

Diabetic retinopathy (DR) is a serious diabetic complication caused by both environmental and genetic factors. Molecular mechanisms of DR may lead to the discovery of reliable prognostic indicators. The current study aimed to clarify the mechanism of microRNA-183 (miR-183) in DR in relation to the PI3K/Akt/VEGF signaling pathway. Microarray-based gene expression profiling of DR was used to identify the differentially expressed genes. Sprague-Dawley rats were used for the establishment of DR models, and then miR-183 was altered by mimic or inhibitor or BTG1 was downregulated by siRNA to explore the regulatory mechanism of miR-183 in DR. Furthermore, the expression of miR-183, CD34, endothelial nitric oxide synthase (eNOS), BTG1 and the PI3K/Akt/VEGF signaling pathway-related genes as well as reactive oxygen species (ROS) level was determined, and the relationship between miR-183 and BTG1 was also verified. Cell growth, cell apoptosis, and angiogenesis were determined. Microarray analysis revealed the involvement of miR-183 in DR via the PI3K/Akt/VEGF signaling pathway by targeting BTG1. Upregulated miR-183 and downregulated BTG1 were observed in retinal tissues of DR rats. miR-183 overexpression activated the PI3K/Akt/VEGF signaling pathway, upregulated CD34, eNOS, and ROS, and inhibited BTG1. BTG1 was confirmed as a target gene of miR-183. miR-183 overexpression or BTG1 knockdown promoted cell growth and tube formation while it suppressed cell apoptosis of vascular endothelial cells in DR rats. In this study, we demonstrated that miR-183 silencing inhibiting cell growth and tube formation in vascular endothelial cells of DR rats via the PI3K/Akt/VEGF signaling pathway by upregulating BTG1.