miR-143 suppresses epithelial-mesenchymal transition and inhibits tumor growth of breast cancer through down-regulation of ERK5

Bone and Extracellular Signal-Related Kinase 5 (ERK5)

Bones are vital for anchoring muscles, tendons, and ligaments, serving as a fundamental element of the human skeletal structure. However, our understanding of bone development mechanisms and the maintenance of bone homeostasis is still limited. Extracellular signal-related kinase 5 (ERK5), a recently identified member of the mitogen-activated protein kinase (MAPK) family, plays a critical role in the pathogenesis and progression of various diseases, especially neoplasms. Recent studies have highlighted ERK5's significant role in both bone development and bone-associated pathologies. This review offers a detailed examination of the latest research on ERK5 in different tissues and diseases, with a particular focus on its implications for bone health. It also examines therapeutic strategies and future research avenues targeting ERK5.

HetFCM: functional co-module discovery by heterogeneous network co-clustering

Functional molecular module (i.e., gene-miRNA co-modules and gene-miRNA-lncRNA triple-layer modules) analysis can dissect complex regulations underlying etiology or phenotypes. However, current module detection methods lack an appropriate usage and effective model of multi-omics data and cross-layer regulations of heterogeneous molecules, causing the loss of critical genetic information and corrupting the detection performance. In this study, we propose a heterogeneous network co-clustering framework (HetFCM) to detect functional co-modules. HetFCM introduces an attributed heterogeneous network to jointly model interplays and multi-type attributes of different molecules, and applies multiple variational graph autoencoders on the network to generate cross-layer association matrices, then it performs adaptive weighted co-clustering on association matrices and attribute data to identify co-modules of heterogeneous molecules. Empirical study on Human and Maize datasets reveals that HetFCM can find out co-modules characterized with denser topology and more significant functions, which are associated with human breast cancer (subtypes) and maize phenotypes (i.e., lipid storage, drought tolerance and oil content). HetFCM is a useful tool to detect co-modules and can be applied to multi-layer functional modules, yielding novel insights for analyzing molecular mechanisms. We also developed a user-friendly module detection and analysis tool and shared it at http://www.sdu-idea.cn/FMDTool.

MicroRNA signatures differentiate types, grades, and stages of breast invasive ductal carcinoma (IDC): miRNA-target interacting signaling pathways

BACKGROUND

Invasive ductal carcinoma (IDC) is the most common form of breast cancer which accounts for 85% of all breast cancer diagnoses. Non-invasive and early stages have a better prognosis than late-stage invasive cancer that has spread to lymph nodes. The involvement of microRNAs (miRNAs) in the initiation and progression of breast cancer holds great promise for the development of molecular tools for early diagnosis and prognosis. Therefore, developing a cost effective, quick and robust early detection protocol using miRNAs for breast cancer diagnosis is an imminent need that could strengthen the health care system to tackle this disease around the world.

METHODS

We have analyzed putative miRNAs signatures in 100 breast cancer samples using two independent high fidelity array systems. Unique and common miRNA signatures from both array systems were validated using stringent double-blind individual TaqMan assays and their expression pattern was confirmed with tissue microarrays and northern analysis. In silico analysis were carried out to find miRNA targets and were validated with q-PCR and immunoblotting. In addition, functional validation using antibody arrays was also carried out to confirm the oncotargets and their networking in different pathways. Similar profiling was carried out in Brca2/p53 double knock out mice models using rodent miRNA microarrays that revealed common signatures with human arrays which could be used for future in vivo functional validation.

RESULTS

Expression profile revealed 85% downregulated and 15% upregulated microRNAs in the patient samples of IDC. Among them, 439 miRNAs were associated with breast cancer, out of which 107 miRNAs qualified to be potential biomarkers for the stratification of different types, grades and stages of IDC after stringent validation. Functional validation of their putative targets revealed extensive miRNA network in different oncogenic pathways thus contributing to epithelial-mesenchymal transition (EMT) and cellular plasticity.

CONCLUSION

This study revealed potential biomarkers for the robust classification as well as rapid, cost effective and early detection of IDC of breast cancer. It not only confirmed the role of these miRNAs in cancer development but also revealed the oncogenic pathways involved in different progressive grades and stages thus suggesting a role in EMT and cellular plasticity during breast tumorigenesis per se and IDC in particular. Thus, our findings have provided newer insights into the miRNA signatures for the classification and early detection of IDC.

Targeting of AKT1 by miR-143-3p Suppresses Epithelial-to-Mesenchymal Transition in Prostate Cancer

An altered expression of miR-143-3p has been previously reported in prostate cancer where it is purported to play a tumor suppressor role. Evidence from other cancers suggests miR-143-3p acts as an inhibitor of epithelial-to-mesenchymal transition (EMT), a key biological process required for metastasis. However, in prostate cancer the interaction between miR-143-3p and EMT-associated mechanisms remains unclear. Therefore, this paper investigated the link between miR-143-3p and EMT in prostate cancer using in vitro and in silico analyses. PCR detected that miR-143-3p expression was significantly decreased in prostate cancer cell lines compared to normal prostate cells. Bioinformatic analysis of The Cancer Genome Atlas Prostate Adenocarcinoma (TCGA PRAD) data showed a significant downregulation of miR-143-3p in prostate cancer, correlating with pathological markers of advanced disease. Functional enrichment analysis confirmed the significant association of miR-143-3p and its target genes with EMT. The EMT-linked gene AKT1 was subsequently shown to be a novel target of miR-143-3p in prostate cancer cells. The in vitro manipulation of miR-143-3p levels significantly altered the cell proliferation, clonogenicity, migration and expression of EMT-associated markers. Further TCGA PRAD analysis suggested miR-143-3p tumor expression may be a useful predictor of disease recurrence. In summary, this is the first study to report that miR-143-3p overexpression in prostate cancer may inhibit EMT by targeting AKT1. The findings suggest miR-143-3p could be a useful diagnostic and prognostic biomarker for prostate cancer.

Suspension state and shear stress enhance breast tumor cells EMT through YAP by microRNA-29b

Except for biochemical effects, suspension state (Sus) is proved to induce epithelial-mesenchymal transition (EMT) of circulating tumor cells (CTCs) mechanically. However, the difference between the effects of the mechanical microenvironment in capillaries (simplified as shear stress (SS) and Sus) and single Sus on EMT is unclear, nor the underlying mechanism. Here, breast tumor cells (BTCs) were loaded with Sus and SS to mimic the situation of CTCs stimulated by these two kinds of mechanics. It was demonstrated that the EMT of BTCs was enhanced by Sus and SS and the mechanotransductor yes-associated protein (YAP) was partially cytoplasmic stored with microRNA (miR)-29b decreased, which was detected by miR sequencing. Though it couldn't possess a feedback regulation, YAP promoted miR-29b expression and posttranscriptionally regulated BTCs EMT through miR-29b, where transforming growth factor β involved. Analysis of clinical database showed that high miR-29b expression was beneficial to high survival rate stabilizing its role of tumor suppressor. This study discovers the mechanism that Sus and SS promote BTCs EMT by YAP through miR-29b posttranscriptionally and highlight the potential of YAP and miR-29b in tumor therapy. The combination of suspension state and shear stress promotes transforming growth factor β involved epithelial-mesenchymal transition by yes-associated protein through microRNA-29b.

Improving the prediction for the response to radiotherapy of clinical tumor samples by using combinatorial model of MicroRNA expression

Purpose: Radiation therapy (RT) is one of the main treatments for cancer. The response to radiotherapy varies widely between individuals and some patients have poor response to RT treatment due to tumor radioresistance. Stratifying patients according to molecular signatures of individual tumor characteristics can improve clinical treatment. In here, we aimed to use clinical and genomic databases to develop miRNA signatures that can predict response to radiotherapy in various cancer types.

Methods: We analyzed the miRNAs profiles using tumor samples treated with RT across eight types of human cancers from TCGA database. These samples were divided into response group (S, n = 224) and progressive disease group (R, n = 134) based on RT response of tumors. To enhance the discrimination for S and R samples, the predictive models based on binary logistic regression were developed to identify the best combinations of multiple miRNAs.

Results: The miRNAs differentially expressed between the groups S and R in each caner type were identified. Total 47 miRNAs were identified in eight cancer types (p values <0.05, t-test), including several miRNAs previously reported to be associated with radiotherapy sensitivity. Functional enrichment analysis revealed that epithelial-to-mesenchymal transition (EMT), stem cell, NF-κB signal, immune response, cell death, cell cycle, and DNA damage response and DNA damage repair processes were significantly enriched. The cancer-type-specific miRNA signatures were identified, which consist of 2-13 of miRNAs in each caner type. Receiver operating characteristic (ROC) analyses showed that the most of individual miRNAs were effective in distinguishing responsive and non-responsive patients (the area under the curve (AUC) ranging from 0.606 to 0.889). The patient stratification was further improved by applying the combinatorial model of miRNA expression (AUC ranging from 0.711 to 0.992). Also, five miRNAs that were significantly associated with overall survival were identified as prognostic miRNAs.

Conclusion: These mRNA signatures could be used as potential biomarkers selecting patients who will benefit from radiotherapy. Our study identified a series of miRNA that were differentially expressed between RT good responders and poor responders, providing useful clues for further functional assays to demonstrate a possible regulatory role in radioresistance.

Effect of Extracellular Signal-Regulated Protein Kinase 5 Inhibition in Clear Cell Renal Cell Carcinoma

(1) Background: Extracellular signal-regulating kinase 5 (ERK5) has been implicated in many cellular functions, including survival, proliferation, and vascularization. Our objectives were to examine the expression and effect of ERK5 in clear cell renal cell carcinoma (ccRCC). (2) Methods: The expressions of ERK5 and its regulating micro-RNA miR-143 were investigated using immunohistochemistry and quantitative reverse transcriptase PCR in surgical specimens of ccRCC patients. With invitro and in vivo studies, we used pharmacologic ERK5 inhibitor XMD8-92, RNA interference, pre-miR-143 transduction, Western blotting, MTS assay, apoptosis assay, and subcutaneous xenograft model. (3) Results: A strong ERK5 expression in surgical specimen was associated with high-grade (p = 0.01), high-recurrence free rate (p = 0.02), and high cancer-specific survival (p = 0.03). Expression levels of ERK5 and miR-143 expression level were correlated (p = 0.049). Pre-miR-143 transduction into ccRCC cell A498 suppressed ERK5 expression. ERK5 inhibition enhanced cyclin-dependent kinase inhibitor p21 expression and decreased anti-apoptotic molecules BCL2, resulting in decreased cell proliferation and survival both in ccRCC and endothelial cells. In the xenograft model, ERK5 inhibitor XMD8-92 suppressed tumor growth. (4) Conclusions: ERK5 is regulated by miR-143, and ERK5 inhibition is a promising target for ccRCC treatment.

Clinical Significance and Regulation of ERK5 Expression and Function in Cancer

Extracellular signal-regulated kinase 5 (ERK5) is a unique kinase among MAPKs family members, given its large structure characterized by the presence of a unique C-terminal domain. Despite increasing data demonstrating the relevance of the ERK5 pathway in the growth, survival, and differentiation of normal cells, ERK5 has recently attracted the attention of several research groups given its relevance in inflammatory disorders and cancer. Accumulating evidence reported its role in tumor initiation and progression. In this review, we explore the gene expression profile of ERK5 among cancers correlated with its clinical impact, as well as the prognostic value of ERK5 and pERK5 expression levels in tumors. We also summarize the importance of ERK5 in the maintenance of a cancer stem-like phenotype and explore the major known contributions of ERK5 in the tumor-associated microenvironment. Moreover, although several questions are still open concerning ERK5 molecular regulation, different ERK5 isoforms derived from the alternative splicing process are also described, highlighting the potential clinical relevance of targeting ERK5 pathways.

Molecular Mechanisms of Epithelial to Mesenchymal Transition Regulated by ERK5 Signaling

Extracellular signal-regulated kinase (ERK5) is an essential regulator of cancer progression, tumor relapse, and poor patient survival. Epithelial to mesenchymal transition (EMT) is a complex oncogenic process, which drives cell invasion, stemness, and metastases. Activators of ERK5, including mitogen-activated protein kinase 5 (MEK5), tumor necrosis factor α (TNF-α), and transforming growth factor-β (TGF-β), are known to induce EMT and metastases in breast, lung, colorectal, and other cancers. Several downstream targets of the ERK5 pathway, such as myocyte-specific enhancer factor 2c (MEF2C), activator protein-1 (AP-1), focal adhesion kinase (FAK), and c-Myc, play a critical role in the regulation of EMT transcription factors SNAIL, SLUG, and β-catenin. Moreover, ERK5 activation increases the release of extracellular matrix metalloproteinases (MMPs), facilitating breakdown of the extracellular matrix (ECM) and local tumor invasion. Targeting the ERK5 signaling pathway using small molecule inhibitors, microRNAs, and knockdown approaches decreases EMT, cell invasion, and metastases via several mechanisms. The focus of the current review is to highlight the mechanisms which are known to mediate cancer EMT via ERK5 signaling. Several therapeutic approaches that can be undertaken to target the ERK5 pathway and inhibit or reverse EMT and metastases are discussed.

Let-7d and miR-185 Impede Epithelial-Mesenchymal Transition by Downregulating Rab25 in Breast Cancer

Objective:

MicroRNAs (miRNAs) expression has deregulated in several cancer types including breast cancer (BC). The present study aims at investigating the role, mechanism, clinical value of let-7d and miR-185 in BC, and the possible correlation these miRNAs with Rab25.

Materials and Methods:

Tumor samples as well adjacent normal tissues (ANT) were acquired from fresh surgical specimens from 110 patients and the expression levels of let-7d, miR-185, Rab25, and snail were evaluated using real-time PCR. The immunohistochemical (IHC) process and western blot were done to detect the level of Rab25 and Snail protein expression in BC samples.

Results:

By comparing miRNAs expression profiles in clinical tissues of 110 patients using real-time PCR, let-7d, and miR-185 expression were dramatically downregulated in BC tissues (P < 0.05). Tumor size, stage, and lymph node metastasis were significantly related to miRNAs expression. Based on qRT-PCR and bioinformatics database analyses, we also recognized Rab25 as a possible target of miR-185 and let-7d. Rab25 expression was enhanced in BC cells and associated inversely with the expression level of mentioned miRNAs. qRT-PCR, immunohistochemistry, and western blot studies verified that Rab25 upregulation increased the levels of the snail, that key transcription factor of epithelial-mesenchymal transition (EMT).

Conclusion:

These findings demonstrated that let-7d and miR-185 inhibited EMT by targeting Rab25 expression in BC. Therefore, targeting the let-7d and miR-185/Rab25 interaction may offer new therapeutic opportunities for treating BC patients.

ERK5 Is Required for Tumor Growth and Maintenance Through Regulation of the Extracellular Matrix in Triple Negative Breast Cancer

Conventional mitogen-activated protein kinase (MAPK) family members regulate diverse cellular processes involved in tumor initiation and progression, yet the role of ERK5 in cancer biology is not fully understood. Triple-negative breast cancer (TNBC) presents a clinical challenge due to the aggressive nature of the disease and a lack of targeted therapies. ERK5 signaling contributes to drug resistance and metastatic progression through distinct mechanisms, including activation of epithelial-to-mesenchymal transition (EMT). More recently a role for ERK5 in regulation of the extracellular matrix (ECM) has been proposed, and here we investigated the necessity of ERK5 in TNBC tumor formation. Depletion of ERK5 expression using the CRISPR/Cas9 system in MDA-MB-231 and Hs-578T cells resulted in loss of mesenchymal features, as observed through gene expression profile and cell morphology, and suppressed TNBC cell migration. In vivo xenograft experiments revealed ERK5 knockout disrupted tumor growth kinetics, which was restored using high concentration Matrigel™ and ERK5-ko reduced expression of the angiogenesis marker CD31. These findings implicated a role for ERK5 in the extracellular matrix (ECM) and matrix integrity. RNA-sequencing analyses demonstrated downregulation of matrix-associated genes, integrins, and pro-angiogenic factors in ERK5-ko cells. Tissue decellularization combined with cryo-SEM and interrogation of biomechanical properties revealed that ERK5-ko resulted in loss of key ECM fiber alignment and mechanosensing capabilities in breast cancer xenografts compared to parental wild-type cells. In this study, we identified a novel role for ERK5 in tumor growth kinetics through modulation of the ECM and angiogenesis axis in breast cancer.

miR-143 acts as an inhibitor of migration and proliferation as well as an inducer of apoptosis in melanoma cancer cells in vitro

Melanoma is a serious form of skin cancers begins in the melanocyte. Micro-RNAs are small noncoding RNA with 19 to 25 nucleotides in length involves in the regulation of a wide range of biological processes. MicroRNAs are affected by an aberrant epigenetic alteration in the tumors that may lead to their dysregulation and formation of cancer. Recently, dysregulation of numerous microRNAs has been reported in different types of cancer. The present study focused on the role of miR-143 in carcinogenesis of melanoma cancer. Here, we evaluated the expression level of miR-143 in three melanoma cell lines in comparison with the normal human epidermal melanocyte cell line. Then, miR-143 gene plasmid transfected into the WM115 cell line, for having the lowest expression of miR-143. In addition, the effect of miR-143 transfection on mRNA and protein levels of metastasis-related genes was performed along with MTT assay, wound healing assay, and flow cytometry. The results showed that mRNA and protein expression levels of metastasis-related genes including MMP-9, E-cadherin, Vimentin, and CXCR4 have been reduced following transfection of miR-143. Moreover, the results of the scratch test showed that miR-143 re-expression inhibited cell migration. Also, the role of miR-143 in the induction of apoptosis and inhibition of proliferation by flow cytometry and MTT was confirmed. As a result, the present study showed that miR-143 was involved in metastatic and apoptotic pathways, suggesting that miR-143 acts as a tumor-suppressor microRNA in melanoma cancer.

High Expression of microRNA-143 is Associated with Favorable Tumor Immune Microenvironment and Better Survival in Estrogen Receptor Positive Breast Cancer

microRNA-143 (miR-143) is a well-known tumor suppressive microRNA that exhibits anti-tumoral function by targeting KRAS signaling pathways in various malignancies. We hypothesized that miR-143 suppresses breast cancer progression by targeting KRAS and its effector molecules. We further hypothesized that high expression of miR-143 is associated with a favorable tumor immune microenvironment of estrogen receptor (ER)-positive breast cancer patients which result in improved survival. Two major publicly available breast cancer cohorts; The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) were used. The miR-143 high expression group was associated with increased infiltration of anti-cancer immune cells and decreased pro-cancer immune cells, as well as enrichment of the genes relating to T helper (Th1) cells resulting in improved overall survival (OS) in ER-positive breast cancer patients. To the best of our knowledge, this is the first study to demonstrate that high expression of miR-143 in cancer cells associates with a favorable tumor immune microenvironment, upregulation of anti-cancer immune cells, and suppression of the pro-cancer immune cells, associating with better survival of the breast cancer patients.

The Emerging Roles of Exosomes as EMT Regulators in Cancer

Epithelial–mesenchymal transition (EMT) causes epithelial cells to lose their polarity and adhesion property, and endows them with migratory and invasive properties to enable them to become mesenchymal stem cells. EMT occurs throughout embryonic development, during wound healing, and in various pathological processes, including tumor progression. Considerable research in the last few decades has revealed that EMT is invariably related to tumor aggressiveness and metastasis. Apart from the interactions between numerous intracellular signaling pathways known to regulate EMT, extracellular modulators in the tumor microenvironment also influence tumor cells to undergo EMT, with extracellular vesicles (EVs) receiving increasing attention as EMT inducers. EVs comprise exosomes and microvesicles that carry proteins, nucleic acids, lipids, and other small molecules to stimulate EMT in cells. Among EVs, exosomes have been investigated in many studies, and their role has been found to be significant with respect to regulating intercellular communications. In this review, we summarize recent studies on exosomes and their cargoes that induce cancer-associated EMT. Furthermore, we describe the possible applications of exosomes as promising therapeutic strategies.

Effects of MIR143 on rat sarcoma signaling networks in solid tumors: A brief overview

Rat sarcoma (RAS) is a well-known oncogene that plays important roles in cancer proliferation, cell survival and cell invasion. RAS exists as three major isoforms, Kirsten rat sarcoma (KRAS), Harvey rat sarcoma (HRAS) and neuroblastoma rat sarcoma (NRAS). Mutations of these genes account for approximately 30% of all cancers. Among them, KRAS mutations are the most common, responsible for 85%, followed by NRAS (12%) and HRAS (3%). Although the development of RAS inhibitors has been explored for over the past decade, so far, no effective inhibitor has been found. MicroRNA (miRNA) are a class of small non-coding RNA that control the gene expression of pleural target genes at the post-transcriptional level. MiRNA play critical roles in the physiological and pathological processes at work in cancers, such as cell proliferation, cell death, cell invasion and metastasis. MicroRNA-143 (MIR143) is known to function as a tumor suppressor in a variety of cancers. One of its known mechanisms is suppression of RAS expression and its effector signaling pathways, such as PI3K/AKT and MAPK/ERK. Within the last five years, we developed a potent chemically modified MIR143-3p that enabled us to elucidate the details of the KRAS signaling networks at play in colon and other cancer cells. In this review, we will discuss the role of MIR143-3p in those RAS signaling networks that are related to various biological processes of cancer cells. In addition, we will discuss the possibility of the use of MIR143 as a therapeutic drug for targeting RAS signaling networks.

The Microrna-143/145 Cluster in Tumors: A Matter of Where and When

The establishment and spreading of cancer involve the acquirement of many biological functions including resistance to apoptosis, enhanced proliferation and the ability to invade the surrounding tissue, extravasate from the primary site, survive in circulating blood, and finally extravasate and colonize distant organs giving origin to metastatic lesions, the major cause of cancer deaths. Dramatic changes in the expression of protein coding genes due to altered transcription factors activity or to epigenetic modifications orchestrate these events, intertwining with a microRNA regulatory network that is often disrupted in cancer cells. microRNAs-143 and -145 represent puzzling players of this game, with apparently contradictory functions. They were at first classified as tumor suppressive due to their frequently reduced levels in tumors, correlating with cell survival, proliferation, and migration. More recently, pro-oncogenic roles of these microRNAs have been described, challenging their simplistic definition as merely tumor-suppressive. Here we review their known activities in tumors, whether oncogenic or onco-suppressive, and highlight how their expression and functions are strongly dependent on their complex regulation downstream and upstream of cytokines and growth factors, on the cell type of expression and on the specific tumor stage.

Cell-free miRNAs as non-invasive biomarkers in breast cancer: Significance in early diagnosis and metastasis prediction

Breast cancer is one of the genetic diseases causing a high mortality among women around the world. Despite the availability of advanced diagnostic tools and treatment strategies, the incidence of breast cancer is increasing every year. This is due to the lack of accurate and reliable biomarkers whose deficiency creates difficulty in early breast cancer recognition, subtypes determination, and metastasis prophecy. Although biomarkers such as ER, PR, Her2, Ki-67, and other genetic platforms e.g. MammaPrint®, Oncotype DX®, Prosigna® or EndoPredict® are available for determination of breast cancer diagnosis and prognosis. However, pertaining to heterogeneous nature, lack of sensitivity, and specificity of these markers, it is still incessant to overcome breast cancer burden. Therefore, a novel biomarker is urgently needed for therapeutic diagnosis and improving prognosis. Lately, it has become more evident that cell-free miRNAs might be useful as good non-invasive biomarkers that are associated with different events in carcinogenesis. For example, some known biomarkers such as miR-21, miR-23a, miR-34a are associated with molecular subtyping and different biomolecular aspects i.e. apoptosis, angiogenesis, metastasis, and miR-1, miR-10b, miR-16 are associated with drug response. Cell-free miRNAs present in human body fluids have proven to be potential biomarkers with significant prognostic and predictive values. Numerous studies have found a distinct expression profile of circulating miRNAs in breast tumour versus non-tumour and in early and advanced-stage, thus implicating its clinical relevance. This review article will highlight the importance of different cell-free miRNAs as a biomarker for early breast cancer detection, subtype classification, and metastasis forecast.

Down-regulated lncRNA SBF2-AS1 inhibits tumorigenesis and progression of breast cancer by sponging microRNA-143 and repressing RRS1

Background

Recently, the roles of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in human diseases have been unveiled, this research was conducted to explore the impacts of lncRNA SET-binding factor 2-antisense RNA1 (SBF2-AS1), miR-143 and resistance to ralstonia solanacearum 1 (RRS1) on breast cancer (BC) development.

Methods

The expression of SBF2-AS1, miR-143 and RRS1 in BC tissues, as well as in MDA-MB-231 and MCF-7 cell lines were assessed. Subsequently, the cells were transfected with miR-143 mimics or/and silenced or overexpressed SBF2-AS1 plasmids, and their negative controls. Then the proliferation, colony formation ability, cell cycle arrest, apoptosis, invasion and migration of the cells were assessed through gain- and loss-of-function experiments. Furthermore, the tumor growth, ki-67 expression and apoptosis in vivo were observed by subcutaneous tumorigenesis in nude mice. Binding relation between SBF2-AS1 and miR-143, and that between miR-143 and RRS1 were confirmed.

Results

SBF2-AS1 and RRS1 were amplified, while miR-143 was reduced in BC tissues and cells. Reduced SBF2-AS1 and elevated miR-143 could repress the proliferation, invasion and migration via restraining RRS1 expression. Moreover, knockdown of SBF2-AS1 up-regulated miR-143 to promote the apoptosis of BC cells by downregulating RRS1, resulting in a prohibitive effect on the tumorigenesis and progression of BC. Results of in vivo experiments indicated that the inhibited SBF2-AS1 and overexpressed miR-143 could restrict BC cell proliferation and promote apoptosis, and decelerate tumor growth in xenografts.

Conclusion

We have discovered in this study that down-regulated SBF2-AS1 could inhibit tumorigenesis and progression of BC by up-regulation miR-143 and repressing RRS1, which provides basic therapeutic considerations for a novel target against BC.

Long noncoding RNA HAGLR acts as a microRNA-143-5p sponge to regulate epithelial-mesenchymal transition and metastatic potential in esophageal cancer by regulating LAMP3

Homeobox D gene cluster antisense growth-associated long noncoding RNA (HAGLR) functions as a crucial regulator in the progression and development of human cancers. We analyzed effects of HAGLR, microRNA (miR)-143-5p and lysosome-associated membrane glycoprotein (LAMP)3 on esophageal cancer (EC) and the related mechanisms. Microarray analysis was used to screen out EC-related genes and the regulation network among HAGLR, miR-143-5p, and LAMP3. The regulatory mechanisms of HAGLR and miR-143-5p in EC were analyzed following the treatment of miR-143-5p mimic, miR-143-5p inhibitor, HAGLR vector, or small interfering RNA against HAGLR in EC cells. The expression of N-cadherin, vimentin, Twist1, Snail1, and E-cadherin as well as the abilities of cell proliferation, invasion, and migration were measured. The effects of the HAGLR/miR-143-5p/LAMP3 axis were determined in vivo by assessing tumor formation in nude mice. The expression of HAGLR and LAMP3 was increased, whereas that of miR-143-5p was diminished in EC tissues and cells. HAGLR could competitively bind to miR-143-5p, and miR-143-5p targeted LAMP3. Down-regulated HAGLR or up-regulated miR-143-5p increased E-cadherin expression and significantly diminished expression of LAMP3, N-cadherin, vimentin, Twist1, and Snail1. Moreover, down-regulated HAGLR inhibited cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT), and tumor growth. Moreover, down-regulation of HAGLR inhibited LAMP3 expression by sponging miR-143-5p, thereby suppressing the progression of EC. Taken together, our results suggest HAGLR acts as a competing endogenous RNA of miR-143-5p to increase the expression of LAMP3, thus promoting EMT, proliferation, invasion, and migration in EC cells.-Yang, C., Shen, S., Zheng, X., Ye, K., Sun, Y., Lu, Y., Ge, H. Long noncoding RNA HAGLR acts as a microRNA-143-5p sponge to regulate epithelial-mesenchymal transition and metastatic potential in esophageal cancer by regulating LAMP3.

Extracellular-Signal Regulated Kinase: A Central Molecule Driving Epithelial-Mesenchymal Transition in Cancer

Epithelial-mesenchymal transition (EMT) is a reversible cellular process, characterized by changes in gene expression and activation of proteins, favoring the trans-differentiation of the epithelial phenotype to a mesenchymal phenotype. This process increases cell migration and invasion of tumor cells, progression of the cell cycle, and resistance to apoptosis and chemotherapy, all of which support tumor progression. One of the signaling pathways involved in tumor progression is the MAPK pathway. Within this family, the ERK subfamily of proteins is known for its contributions to EMT. The ERK subfamily is divided into typical (ERK 1/2/5), and atypical (ERK 3/4/7/8) members. These kinases are overexpressed and hyperactive in various types of cancer. They regulate diverse cellular processes such as proliferation, migration, metastasis, resistance to chemotherapy, and EMT. In this context, in vitro and in vivo assays, as well as studies in human patients, have shown that ERK favors the expression, function, and subcellular relocalization of various proteins that regulate EMT, thus promoting tumor progression. In this review, we discuss the mechanistic roles of the ERK subfamily members in EMT and tumor progression in diverse biological systems.

Transforming growth factor‑β/miR‑143‑3p/cystatin B axis is a therapeutic target in human ovarian cancer

We previously reported that cystatin B (CSTB) is a progression marker of human ovarian cancer (OC); however, the regulatory mechanism of CSTB and its function in OC remain unclear. The present study aimed to explore the mechanism underlying transforming growth factor-β (TGF‑β) 1‑mediated CSTB regulation, and to examine the function of CSTB on OC cell proliferation and apoptosis. Using the online program, miRWalk, a microRNA (miR)‑143‑3p was detected, which contains a homologous sequence of the potential binding site to the 3'‑untranslated region (3'‑UTR) of CSTB. A dual‑luciferase reporter assay confirmed the interaction between miR‑143‑3p and CSTB 3'‑UTR. Treating OC cells with miR‑143‑3p mimics or inhibitors resulted in a decrease or an increase of CSTB expression at mRNA and protein levels, respectively. Additionally, CSTB was significantly overexpressed, whereas miR‑143‑3p was downregulated in human OC tissues compared with normal ovarian tissues. A negative correlation between miR‑143‑3p and CSTB mRNA expression was observed in ovarian malignant tumors. The levels of primary and mature miR‑143‑3p expression were upregulated in OC cells after TGF‑β1 treatment; the action of TGF‑β1 was abolished in the presence of an inhibitor of TGF‑β type I receptor. These results indicated an axis between TGF‑β, miR‑143‑3p and CSTB in OC cells. Furthermore, high levels of CSTB expression were associated with the poor overall survival of patients with OC. Knockdown of CSTB resulted in a decrease in OC cell proliferation and arrested cells in G2/M phase. In addition, suppression of CSTB induced cell apoptosis. In conclusion, CSTB was overexpressed and miR‑143‑3p was downregulated in ovarian malignant tumors. Mature miR‑143‑3p directly bound CSTB 3'‑UTR, leading to a decrease in CSTB expression in OC cells, which was regulated by TGF‑β1. Our findings suggest the potential therapeutic application of targeting the TGF‑β/miR‑143‑3p/CSTB axis for treating patients with OC.

miR-143 inhibits proliferation and metastasis of nasopharyngeal carcinoma cells via targeting FMNL1 based on clinical and radiologic findings

Mounting evidence has reported that microRNA-143 (miR-143) is involved in the development of multiple cancers. To investigate the underlying mechanisms of miR-143 regulating proliferation and metastasis in nasopharyngeal carcinoma (NPC) cells, we evaluated the levels of miR-143 and formin-like protein 1 (FMNL1) in NPC tissues. The results of qRT-PCR and Western blot analysis showed that the expression of miR-143 was decreased, while FMNL1 was increased in NPC tissues. The expression of miR-143 was significantly elevated in NPC cells compared with that of human nasopharyngeal epithelial cells. The results of MiRcode prediction, dual-luciferase reporter, and Western blot analysis assays indicated that miR-143 negatively regulated the expression of FMNL1 (r²  = 0.4365P = 0.0001). Overexperssion of miR-143 or FMNL1 knockdown inhibited cell proliferation, migration, and invasion in NPC cells (P < 0.05). Ectopic expression of FMNL1 undermined the inhibition effect of miR-143 on proliferation, migration, and invasion in NPC cells. The findings of this study revealed that miR-143 functioned as a tumor suppressor and inhibited the NPC progression by targeting FMNL1.

Impact of ERK5 on the Hallmarks of Cancer

Extracellular signal-regulated kinase 5 (ERK5) belongs to the mitogen-activated protein kinase (MAPK) family that consists of highly conserved enzymes expressed in all eukaryotic cells and elicits several biological responses, including cell survival, proliferation, migration, and differentiation. In recent years, accumulating lines of evidence point to a relevant role of ERK5 in the onset and progression of several types of cancer. In particular, it has been reported that ERK5 is a key signaling molecule involved in almost all the biological features of cancer cells so that its targeting is emerging as a promising strategy to suppress tumor growth and spreading. Based on that, in this review, we pinpoint the hallmark-specific role of ERK5 in cancer in order to identify biological features that will potentially benefit from ERK5 targeting.

Integrated Analysis of Mouse and Human Gastric Neoplasms Identifies Conserved microRNA Networks in Gastric Carcinogenesis

BACKGROUND & AIMS

microRNAs (miRNAs) are small noncoding RNAs that bind to the 3' untranslated regions of mRNAs to promote their degradation or block their translation. Mice with disruption of the trefoil factor 1 gene (Tff1) develop gastric neoplasms. We studied these mice to identify conserved miRNA networks involved in gastric carcinogenesis.

METHODS

We performed next-generation miRNA sequencing analysis of normal gastric tissues (based on histology) from patients without evidence of gastric neoplasm (n = 64) and from TFF1-knockout mice (n = 22). We validated our findings using 270 normal gastric tissues (including 61 samples from patients without evidence of neoplastic lesions) and 234 gastric tumor tissues from 3 separate cohorts of patients and from mice. We performed molecular and functional assays using cell lines (MKN28, MKN45, STKM2, and AGS cells), gastric organoids, and mice with xenograft tumors.

RESULTS

We identified 117 miRNAs that were significantly deregulated in mouse and human gastric tumor tissues compared with nontumor tissues. We validated changes in levels of 6 miRNAs by quantitative real-time polymerase chain reaction analyses of neoplastic gastric tissues from mice (n = 39) and 3 independent patient cohorts (n = 332 patients total). We found levels of MIR135B-5p, MIR196B-5p, and MIR92A-5p to be increased in tumor tissues, whereas levels of MIR143-3p, MIR204-5p, and MIR133-3p were decreased in tumor tissues. Levels of MIR143-3p were reduced not only in gastric cancer tissues but also in normal tissues adjacent to tumors in humans and low-grade dysplasia in mice. Transgenic expression of MIR143-3p in gastric cancer cell lines reduced their proliferation and restored their sensitivity to cisplatin. AGS cells with stable transgenic expression of MIR143-3p grew more slowly as xenograft tumors in mice than control AGS cells; tumor growth from AGS cells that expressed MIR143-3p, but not control cells, was sensitive to cisplatin. We identified and validated bromodomain containing 2 (BRD2) as a direct target of MIR143-3p; increased levels of BRD2 in gastric tumors was associated with shorter survival times for patients.

CONCLUSIONS

In an analysis of miRNA profiles of gastric tumors from mice and human patients, we identified a conserved signature associated with the early stages of gastric tumorigenesis. Strategies to restore MIR143-3p or inhibit BRD2 might be developed for treatment of gastric cancer.

miR-425 suppresses EMT and the development of TNBC (triple-negative breast cancer) by targeting the TGF-β 1/SMAD 3 signaling pathway

Background: EMT has a crucial effect on the progression and metastasis of tumors. This work will elucidate the role of miR-425 in EMT and the development of TNBC. Methods: The differential miRNA expression among non-tumor, para-tumor (adjacent tissue of tumor) and tumor tissues was analyzed. The luciferase activities of TGF-β1 3′UTR treated with miR-425 were determined. Then human breast cancer cell lines were treated with mimics or inhibitors of miR-425, and then the cell proliferation and migration, and invasion ability were assessed. The expression of TGF-β1 and markers of epithelial cells and mesenchymal cells were analyzed. The influences of miR-425 on the development of TNBC through inducing EMT by targeting the TGF-β1/SMAD3 signaling pathway in TNBC cell lines were investigated. Furthermore, xenograft mice were used to explore the potential roles of miR-425 on EMT and the development of TNBC in vivo. Results: Compared with non-tumor tissues, 9 miRNAs were upregulated and 3 miRNAs were down-regulated in tumor tissues. The relative expression of miR-425 in tumor tissues was obviously much lower than that in para-tumor and non-tumor tissues. MiR-425 suppressed TGF-β1 expression, and further inhibited expression of mesenchymal cell markers, while it exerted effects on cell proliferation and migration of TNBC cell lines. Moreover, the agomir of miR-425 could protect against the development process in a murine TNBC xenograft model. Conclusions: Our results demonstrated that miR-425 targets TGF-β1, and was a crucial suppressor on EMT and the development of TNBC through inhibiting the TGF-β1/SMAD3 signaling pathway. This suggests that aiming at the TGF-β1/SMAD3 signaling pathway by enhancing relative miR-425 expression, is a feasible therapy strategy for TNBC.

EMT has a crucial effect on the progression and metastasis of tumors.

The PI3K/Akt/GSK-3β/ROS/eIF2B pathway promotes breast cancer growth and metastasis via suppression of NK cell cytotoxicity and tumor cell susceptibility

Objective

To examine the effect of pSer9-GSK-3β on breast cancer and to determine whether the underlying metabolic and immunological mechanism is associated with ROS/eIF2B and natural killer (NK) cells.

Methods

We employed TWS119 to inactivate GSK-3β by phosphorylating Ser9 and explored its effect on breast cancer and NK cells. The expression of GSK-3β, natural killer group 2 member D (NKG2D) ligands, eIF2B was quantified by PCR and Western blot. We measured intracellular reactive oxygen species (ROS) and mitochondrial ROS using DCFH-DA and MitoSOX^TM probe, respectively, and conducted quantitative analysis of cellular respiration on 4T1 cells with mitochondrial respiratory chain complex I/III kits.

Results

Our investigation revealed that TWS119 downregulated NKG2D ligands (H60a and Rae1), suppressed the cytotoxicity of NK cells, and promoted the migration of 4T1 murine breast cancer cells. Nevertheless, LY290042, which attenuates p-GSK-3β formation by inhibiting the PI3K/Akt pathway, reversed these effects. We also found that higher expression of pSer9-GSK-3β induced higher levels of ROS, and observed that abnormality of mitochondrial respiratory chain complex I/III function induced the dysfunction of GSK-3β-induced electron transport chain, naturally disturbing the ROS level. In addition, the expression of NOX3 and NOX4 was significantly up-regulated, which affected the generation of ROS and associated with the metastasis of breast cancer. Furthermore, we found that the expression of pSer535-eIF2B promoted the expression of NKG2D ligands (Mult-1 and Rae1) following by expression of pSer9-GSK-3β and generation of ROS.

Conclusions

The PI3K/Akt/GSK-3β/ROS/eIF2B pathway could regulate NK cell activity and sensitivity of tumor cells to NK cells, which resulted in breast cancer growth and lung metastasis. Thus, GSK-3β is a promising target of anti-tumor therapy.

miR‑185‑5p inhibits F‑actin polymerization and reverses epithelial mesenchymal transition of human breast cancer cells by modulating RAGE

In our previous study, advanced glycosylation end-product specific receptor (RAGE) was observed to bind to S100A8/A9 and cause epithelial mesenchymal transition (EMT). The results from target gene prediction revealed that microRNA (miR)-185-5p had a RAGE binding site. However, the function of miR-185-5p in the invasion and migration of breast cancer remains ambiguous. In the present study, the expression of miR-185-5p was examined in breast cancer tissues and cells. Clinical features revealed a negative correlation between miR-185-5p and tumor size, as well as in tumor differentiation and lymph node metastasis in breast cancer. In addition, miR-185-5p was negatively associated with RAGE, and this miRNA reversed the EMT of breast cancer by modulating RAGE in vitro. In addition, miR-185-5p inhibited the S100A8/A9-induced EMT of breast cancer cells by the nuclear factor-κB/Snail signaling pathway. Notably, miR-185-5p upregulation inhibited the F-actin polymerization induced by S100A8/A9 in breast cancer. Furthermore, overexpression of miR-185-5p and reduction of RAGE inhibited lung metastasis node in vivo. Thus, miR-185-5p represents a potential therapeutic target in breast cancer by modulating RAGE.

Downregulation of miR-3127-5p promotes epithelial-mesenchymal transition via FZD4 regulation of Wnt/β-catenin signaling in non-small-cell lung cancer

MiR-3127-5p has been implicated as a tumor-suppressive microRNA (miRNA) in non-small-cell lung cancer (NSCLC) and its expression was associated with tumor recurrence and poor prognosis. The aim of this study was to determine whether miR-3127-5p regulates epithelial-mesenchymal transition (EMT) in NSCLC, and to investigate the underlying mechanisms. Using qRT-PCR, we examined the expression levels of miR-3127-5p in a cohort of primary NSCLC specimens with and without distant metastasis. We further performed a series of in vitro and in vivo experiments to investigate the effects and underlying mechanism of miR-3127-5p on EMT, cell migration, invasion, and adhesion in NSCLC. We found that metastatic NSCLC tissues showed markedly downregulated miR-3127-5p expression. Transforming growth factor-β1 (TGF-β1) treatment induced EMT in A549 and H1299 cells, and downregulation of miR-3127-5p could result in the similar effect. Mechanically, we demonstrated that frizzled-4 (FZD4) is a target gene and miR-3127-5p exerts its effects by regulating the Wnt/β-catenin signaling. In addition, the expression levels of FZD4 and miR-3127-5p were also negatively associated in both clinical and xenografted tumors. Overall, these findings suggest that downregulation of miR-3127-5p promotes EMT through activating the Wnt/FZD4/β-catenin signaling pathway and may represent a therapeutic target for NSCLC metastasis.

Differentially expressed microRNAs in lung adenocarcinoma invert effects of copy number aberrations of prognostic genes

In many cancers, significantly down- or upregulated genes are found within chromosomal regions with DNA copy number alteration opposite to the expression changes. Generally, this paradox has been overlooked as noise, but can potentially be a consequence of interference of epigenetic regulatory mechanisms, including microRNA-mediated control of mRNA levels.

To explore potential associations between microRNAs and paradoxes in non-small-cell lung cancer (NSCLC) we curated and analyzed lung adenocarcinoma (LUAD) data, comprising gene expressions, copy number aberrations (CNAs) and microRNA expressions. We integrated data from 1,062 tumor samples and 241 normal lung samples, including newly-generated array comparative genomic hybridization (aCGH) data from 63 LUAD samples.

We identified 85 “paradoxical” genes whose differential expression consistently contrasted with aberrations of their copy numbers. Paradoxical status of 70 out of 85 genes was validated on sample-wise basis using The Cancer Genome Atlas (TCGA) LUAD data. Of these, 41 genes are prognostic and form a clinically relevant signature, which we validated on three independent datasets. By meta-analysis of results from 9 LUAD microRNA expression studies we identified 24 consistently-deregulated microRNAs. Using TCGA-LUAD data we showed that deregulation of 19 of these microRNAs explains differential expression of the paradoxical genes.

Our results show that deregulation of paradoxical genes is crucial in LUAD and their expression pattern is maintained epigenetically, defying gene copy number status.

Therapeutic impacts of microRNAs in breast cancer by their roles in regulating processes involved in this disease

Breast cancer is the most common cancer in women around the world. So far, many attempts have been made to treat this disease, but few effective treatments have been discovered. In this work, we reviewed the related articles in the limited period of time, 2000-2016, through search in PubMed, Scopus database, Google Scholar, and psychology and psychiatry literature (PsycINFO). We selected the articles about the correlation of microRNAs (miRNAs) and breast cancer in the insight into therapeutic applicability from mentioned genetics research databases. The miRNAs as an effective therapy for breast cancer was at the center of our attention. Hormone therapy and chemotherapy are two major methods that are being used frequently in breast cancer treatment. In the search for an effective therapy for breast cancer, miRNAs suggest a promising method of treatment. miRNAs are small, noncoding RNAs that can turn genes on or off and can have critical roles in cancer treatment; therefore, in the near future, usage of these biological molecules in breast cancer treatment can be considered a weapon against most common cancer-related concerns in women. Here, we discuss miRNAs and their roles in various aspects of breast cancer treatment to help find an alternative and effective way to treat or even cure this preventable disease.

cfa-miR-143 Promotes Apoptosis via the p53 Pathway in Canine Influenza Virus H3N2-Infected Cells

MicroRNAs regulate multiple aspects of the host response to viral infection. This study verified that the expression of cfa-miR-143 was upregulated in vivo and in vitro by canine influenza virus (CIV) H3N2 infection. To understand the role of cfa-miR-143 in CIV-infected cells, the target gene of cfa-miR-143 was identified and assessed for correlations with proteins involved in the apoptosis pathway. A dual luciferase reporter assay showed that cfa-miR-143 targets insulin-like growth factor binding protein 5 (Igfbp5). Furthermore, a miRNA agomir and antagomir of cfa-miR-143 caused the downregulation and upregulation of Igfbp5, respectively, in CIV-infected madin-darby canine kidney (MDCK) cells. This study demonstrated that cfa-miR-143 stimulated p53 and caspase3 activation and induced apoptosis via the p53 pathway in CIV H3N2-infected cells. In conclusion, CIV H3N2 induced the upregulation of cfa-miR-143, which contributes to apoptosis via indirectly activating the p53-caspase3 pathway.

miR-143 and miR-145 inhibit gastric cancer cell migration and metastasis by suppressing MYO6

Metastasis is a major clinical obstacle responsible for the high mortality and poor prognosis of gastric cancer (GC). MicroRNAs (miRNAs) are critical mediators of metastasis that act by modulating their target genes. In this study, we found that miR-143 and miR-145 act via a common target gene, MYO6, to regulate the epithelial–mesenchymal transition (EMT) and inhibit metastasis. We determined that miR-143 and miR-145 were downregulated in GC, and the ectopic expression of miR-143 and/or miR-145 inhibited GC cell migration and metastasis. Furthermore, MYO6 was identified as a direct common target of miR-143 and miR-145 and was elevated in GC. Silencing of MYO6 resulted in a metastasis-suppressive activity similar to that of miR-143 and miR-145, while restoring MYO6 attenuated the anti-metastatic or anti-EMT effects caused by miR-143 and miR-145. Clinically, an inverse correlation was observed between miR-143/145 levels and MYO6 levels in GC tissues, and either miR-143/145 downregulation or MYO6 upregulation was associated with more malignant phenotypes in patients with GC. In conclusion, miR-143 and miR-145 suppress GC cell migration and metastasis by inhibiting MYO6 expression and the EMT, which provides a novel mechanism and promising therapeutic target for the treatment of GC metastasis.

LncRNA UCA1 promotes the invasion and EMT of bladder cancer cells by regulating the miR-143/HMGB1 pathway

The long non-coding RNA (lncRNA) urothelial carcinoma associated 1 (UCA1) is an oncogenic lncRNA in bladder cancer, and its upregulation is associated with enhanced cell invasion. However, the underlying mechanism remains to be elucidated. The present study demonstrated that UCA1 was positively associated with cell invasion ability and promoted epithelial-mesenchymal transition (EMT) of bladder cancer cells by inducing high mobility group box 1 (HMGB1). Furthermore, bioinformatics and luciferase reporter assays demonstrated binding sites of the tumor suppressive miR-143 within UCA1 and the 3'untranslated region of HMGB1. UCA1 negatively regulated miR-143 expression in a dose-dependent manner in bladder cancer cells. In addition, UCA1 and HMGB1 were upregulated and miR-143 was downregulated in bladder cancer specimens. Overall, the data suggested that UCA1 may promote the invasion and EMT of bladder cancer cells by regulating the miR-143/HMGB1 pathway, which exhibits an important regulatory role in the pathology of bladder cancer.

MicroRNA-143 inhibits cell growth by targeting ERK5 and MAP3K7 in breast cancer

This study aimed to investigate the function and mechanism of microRNA-143 (miR-143) in the occurrence and development of breast cancer (BC). A total of 30 BC tissues, 30 corresponding noncancerous tissues, and 10 normal control (NC) breast tissues were obtained to detect the levels of miR-143, extracellular signal-regulated kinase 5 (ERK5) and mitogen-activated protein 3 kinase 7 (MAP3K7) using RT-qPCR, western blotting or immunohistochemistry. The correlation of miR-143 with ERK5 or MAP3K7 was evaluated using Pearson correlation analysis. MCF-7 cells were transiently transfected with miR-143 mimic, miR-143 inhibitor, miR-143 mimic/inhibitor + si-ERK5, si-MAP3K7 or si-cyclin D1. Then, cell growth was evaluated by MTT assay and the expressions of phospho-ERK5 (p-ERK5), ERK5, p-MAP3K7, MAP3K7 and cyclin D1 were detected by western blotting. Results showed that, compared with noncancerous tissues or NC breast tissues, miR-143 level was decreased, while p-ERK5, ERK5, p-MAP3K7 and MAP3K7 expressions were increased in BC tissues (all P<0.01). The miR-143 level was negatively correlated with the mRNA level of ERK5 or MAP3K7 (r=-4.231 or r=-4.280, P<0.01). In addition, up-regulated miR-143 significantly decreased the expressions of p-ERK5, ERK5, p-MAP3K7, MAP3K7 and cyclin D1 (all P<0.01), as well as cell viability in MCF-7 cells (all P<0.05) while the effect of down-regulated miR-143 was the opposite. In conclusion, both ERK5 and MAP3K7 may be the target genes of miR-143. Increased expression of miR-143 can inhibit cell growth, which may be associated with ERK5 and MAP3K7 expressions in BC.

Senescence-Associated MicroRNAs

Senescent cells arise as a consequence of cellular damage and can have either a detrimental or advantageous impact on tissues and organs depending on the specific cell type and metabolic state. As senescent cells accumulate in tissues with advancing age, they have been implicated in many age-related declines and diseases. The major facets of senescence include two pathways responsible for establishing and maintaining a senescence program, p53/CDKN1A(p21) and CDKN2A(p16)/RB, as well as the senescence-associated secretory phenotype. Numerous MicroRNAs influence senescence by modulating the abundance of key senescence regulatory proteins, generally by lowering the stability and/or translation of mRNAs that encode such factors. Accordingly, understanding the molecular mechanisms by which MicroRNAs influence senescence will enable diagnostic and therapeutic opportunities directed at senescent cells. Here, we review senescence-associated (SA)-MicroRNAs and discuss their implications in senescence-relevant pathologies.

MicroRNA-27a contributes to the malignant behavior of gastric cancer cells by directly targeting PH domain and leucine-rich repeat protein phosphatase 2

Background

Accumulating evidence indicates that microRNA-27a (miR-27a) is involved in carcinogenesis and tumor progression. However, the exact function and molecular mechanism of miR-27a in gastric cancer remain unclear.

Methods

Quantitative real-time PCR (qRT-PCR) was used to quantify the expression of miR-27a and its target gene. The function of miR-27a in gastric cancer was investigated through in vitro and in vivo assays (MTT assay, colony formation assay, flow cytometry assay, wound healing assay, migration and invasion assay, immunohistochemistry (IHC), immunofluorescence (IF) and Western blot). A luciferase reporter assay was conducted to confirm the target gene of miR-27a.

Results

We found that miR-27a was commonly overexpressed in gastric cancer and high expression of miR-27a was associated with distant metastasis, lymph node metastasis, advanced T stage and advanced clinical stage. Functional assays demonstrated that overexpression of miR-27a in AGS cells accelerated cell proliferation, migration and invasion and suppressed apoptosis. Meanwhile, opposite results were observed in SGC-7901 cells when miR-27a was suppressed. Consistently, down-regulation of miR-27a inhibited the growth and metastasis of engrafted tumors in vivo. Furthermore, we found PH domain and leucine-rich repeat protein phosphatase 2 (PHLPP2) to be a new target of miR-27a, and downregulation of PHLPP2 could rescue the effect of anti-miR-27a in gastric cancer cells. In addition, miR-27a-mediated suppression of PHLPP2 led to stimulation of the AKT/GSK3β pathway.

Conclusions

Our data suggest that miR-27a functions as a crucial oncogenic miRNA in gastric cancer. It can promote proliferation and metastasis of tumor cells by suppressing PHLPP2 and activating the AKT/GSK3β pathway. Therefore, miR-27a is a potential novel therapeutic target in gastric cancer treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0516-2) contains supplementary material, which is available to authorized users.

MicroRNAs regulate the epithelial-mesenchymal transition and influence breast cancer invasion and metastasis

MicroRNAs are small RNA molecules that play a major role in the post-transcriptional regulation of genes and influence the development, differentiation, proliferation, and apoptosis of cells and the development and progression of tumors. The epithelial-mesenchymal transition is a process by which epithelial cells morphologically transform into cells with a mesenchymal phenotype. The epithelial-mesenchymal transition plays a highly important role in tumor invasion and metastasis. Increasing evidence indicates that microRNAs are tightly associated with epithelial-mesenchymal transition regulation in tumor cells. In breast cancer, various microRNA molecules have been identified as epithelial-mesenchymal transition inducers or inhibitors, which, through different mechanisms and signaling pathways, participate in the regulation of breast cancer invasion and metastasis among various biological behaviors. The epithelial-mesenchymal transition-related microRNAs in breast cancer provide valuable molecules for researching cell invasion and metastasis, and they also provide candidate targets that may be significant for the targeted therapy of breast cancer.

A Functional rs353293 Polymorphism in the Promoter of miR-143/145 Is Associated with a Reduced Risk of Bladder Cancer

BACKGROUND AND OBJECTIVES

MicroRNA (miR)-143/145, known as tumor suppressors, can promote cell apoptosis and differentiation, and suppress cell proliferation, invasion and migration. We performed a case-control study to investigate the association of rs353293 in the promoter region of miR-143/145 with bladder cancer risk.

METHODS

In total, 869 subjects including 333 cases and 536 controls were enrolled in this study, and the rs353293 polymorphism was genotyped by using a Taqman assay. The promoter activity was measured by the Dual-Luciferase Assay System.

RESULTS

We calculated an adjusted odds ratio of 0.64 for the presence of either AA/AG genotypes (95% CI 0.46-0.90) and 0.64 (95% CI 0.47-0.87) for carrying at least one A allele in bladder cancer. Stratified analyses showed that the AA/AG genotypes and the A allele were less prevalent in patients with low grade tumors, compared to those harboring higher grade bladder cancers (adjusted OR = 0.53, 95% CI, 0.30-0.94, P = 0.03 and adjusted OR = 0.54, 95% CI, 0.32-0.92, P = 0.02, respectively). In vitro luciferase reporter analysis showed that rs353293A allele had a lower activity compared with the rs353293G allele (P < 0.001).

CONCLUSION

These findings suggest that the functional rs353293 polymorphism may be a useful biomarker to predict the risk of bladder cancer.