A decrease in miR-150 regulates the malignancy of pancreatic cancer by targeting c-Myb and MUC4

Diverse activity of miR-150 in Tumor development: shedding light on the potential mechanisms

There is a growing interest to understand the role and mechanism of action of microRNAs (miRNAs) in cancer. The miRNAs are defined as short non-coding RNAs (18-22nt) that regulate fundamental cellular processes through mRNA targeting in multicellular organisms. The miR-150 is one of the miRNAs that have a crucial role during tumor cell progression and metastasis. Based on accumulated evidence, miR-150 acts as a double-edged sword in malignant cells, leading to either tumor-suppressive or oncogenic function. An overview of miR-150 function and interactions with regulatory and signaling pathways helps to elucidate these inconsistent effects in metastatic cells. Aberrant levels of miR-150 are detectable in metastatic cells that are closely related to cancer cell migration, invasion, and angiogenesis. The ability of miR-150 in regulating of epithelial-mesenchymal transition (EMT) process, a critical stage in tumor cell migration and metastasis, has been highlighted. Depending on the cancer cells type and gene expression profile, levels of miR-150 and potential target genes in the fundamental cellular process can be different. Interaction between miR-150 and other non-coding RNAs, such as long non-coding RNAs and circular RNAs, can have a profound effect on the behavior of metastatic cells. MiR-150 plays a significant role in cancer metastasis and may be a potential therapeutic target for preventing or treating metastatic cancer.

Small RNA sequencing analysis of peptide-affinity isolated plasma extracellular vesicles distinguishes pancreatic cancer patients from non-affected individuals

Pancreatic ductal adenocarcinoma (PDAC) has a high fatality rate, mainly due to its asymptomatic nature until late-stage disease and therefore delayed diagnosis that leads to a lack of timely treatment intervention. Consequently, there is a significant need for better methods to screen populations that are at high risk of developing PDAC. Such advances would result in earlier diagnosis, more treatment options, and ultimately better outcomes for patients. Several recent studies have applied the concept of liquid biopsy, which is the sampling of a biofluid (such as blood plasma) for the presence of disease biomarkers, to develop screening approaches for PDAC; several of these studies have focused on analysis of extracellular vesicles (EVs) and their cargoes. While these studies have identified many potential biomarkers for PDAC that are present within EVs, their application to clinical practice is hindered by the lack of a robust, reproducible method for EV isolation and analysis that is amenable to a clinical setting. Our previous research has shown that the Vn96 synthetic peptide is indeed a robust and reproducible method for EV isolation that has the potential to be used in a clinical setting. We have therefore chosen to investigate the utility of the Vn96 synthetic peptide for this isolation of EVs from human plasma and the subsequent detection of small RNA biomarkers of PDAC by Next-generation sequencing (NGS) analysis. We find that analysis of small RNA from Vn96-isolated EVs permits the discrimination of PDAC patients from non-affected individuals. Moreover, analyses of all small RNA species, miRNAs, and lncRNA fragments are most effective at segregating PDAC patients from non-affected individuals. Several of the identified small RNA biomarkers have been previously associated with and/or characterized in PDAC, indicating the validity of our findings, whereas other identified small RNA biomarkers may have novel roles in PDAC or cancer in general. Overall, our results provide a basis for a clinically-amendable detection and/or screening strategy for PDAC using a liquid biopsy approach that relies on Vn96-mediated isolation of EVs from plasma.

Association of mucin family members with prognostic significance in pancreatic cancer patients: A meta-analysis

OBJECTIVE

The role of biomarkers in the early diagnosis and prognosis prediction of tumors has been paid more and more attention by researchers. Mucins are markers that have been found to have an abnormal expression in many tumors in recent years, which have been proved to have a predictive effect on the prognosis of tumors such as cholangiocarcinoma and colon cancer. However, whether it can predict the prognosis of pancreatic cancer remains unknown. The purpose of our study is to investigate whether the mucins and their subtypes are related to the prognosis of patients with pancreatic cancer.

METHODS

We systematically searched the Pubmed, Embase, and Cochrane Library for all eligible studies on the relationship between mucin and the prognosis of patients with pancreatic cancer up to November 2021. We used R 4.12 to calculate the combined risk ratio (HR) and 95% confidence interval (CI). For studies that did not provide HR values, we used scientific methods to calculate their values as accurately as possible. We used fixed effect model due to low heterogeneity. Subgroup analysis and sensitivity analysis were used to study heterogeneity. The funnel plot and Egger test were used to test whether the publication bias existed. The trim and filling method were used to evaluate the impact of publication bias on the results of the study.

RESULTS

A total of 18 studies were included in this meta-analysis, including 4 subtypes of mucin family members and 1643 patients. There was a slight heterogeneity between studies (I2 = 24.4%, P = 0.14). Meta-analysis showed that MUC4 (HR = 2.04, 95%CI 1.21;3.45), MUC16 (HR = 2.10, 95%CI 1.31;3.37), and whole mucin (HR = 1.32, 95%CI 1.07;1.63). The expression level was negatively correlated with the prognosis of pancreatic cancer patients, MUC1 (HR = 1.09, 95%CI 0.77;1.54), MUC5 (HR = 1.03, 95%CI 0.47;2.25) The expression level was not related to the prognosis of pancreatic cancer patients.

CONCLUSION

The meta-analysis demonstrated that the overall expression level of mucin and the expression levels of MUC4 and MUC16 were important prognostic predictors for pancreatic cancer patients. MUC1 and MUC5 had no predictive value for the prognosis of pancreatic cancer patients. Future studies should validate these and other promising biomarkers.

TRIAL REGISTRATION

PROSPERO registration number is CRD42021291962. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021291962.

Oncogenomic Changes in Pancreatic Cancer and Their Detection in Stool

Pancreatic cancer (PC) is an aggressive malignancy with a dismal prognosis. To improve patient survival, the development of screening methods for early diagnosis is pivotal. Oncogenomic alterations present in tumor tissue are a suitable target for non-invasive screening efforts, as they can be detected in tumor-derived cells, cell-free nucleic acids, and extracellular vesicles, which are present in several body fluids. Since stool is an easily accessible source, which enables convenient and cost-effective sampling, it could be utilized for the screening of these traces. Herein, we explore the various oncogenomic changes that have been detected in PC tissue, such as chromosomal aberrations, mutations in driver genes, epigenetic alterations, and differentially expressed non-coding RNA. In addition, we briefly look into the role of altered gut microbiota in PC and their possible associations with oncogenomic changes. We also review the findings of genomic alterations in stool of PC patients, and the potentials and challenges of their future use for the development of stool screening tools, including the possible combination of genomic and microbiota markers.

Mucin expression, epigenetic regulation and patient survival: A toolkit of prognostic biomarkers in epithelial cancers

Twenty mucin genes have been identified and classified in two groups (encoding secreted and membrane-bound proteins). Secreted mucins participate in mucus formation by assembling a 3-dimensional network via oligomerization, whereas membrane-bound mucins are anchored to the outer membrane mediating extracellular interactions and cell signaling. Both groups have been associated with carcinogenesis progression in epithelial cancers, and are therefore considered as potential therapeutic targets. In the present review, we discuss the link between mucin expression patterns and patient survival and propose mucins as prognosis biomarkers of epithelial cancers (esophagus, gastric, pancreatic, colorectal, lung, breast or ovarian cancers). We also investigate the relationship between mucin expression and overall survival in the TCGA dataset. In particular, epigenetic mechanisms regulating mucin gene expression, such as aberrant DNA methylation and histone modification, are interesting as they are also associated with diagnosis or prognosis significance. Indeed, mucin hypomethylation has been shown to be associated with carcinogenesis progression and was linked to prognosis in colon cancer or pancreatic cancer patients. Finally we describe the relationship between mucin expression and non-coding RNAs that also may serve as biomarkers. Altogether the concomitant knowledge of specific mucin-pattern expression and epigenetic regulation could be translated as biomarkers with a better specificity/sensitivity performance in several epithelial cancers.

How metformin affects various malignancies by means of microRNAs: a brief review

Metformin known as the first-line orally prescribed drug for lowering blood glucose in type II diabetes (T2DM) has recently found various therapeutic applications including in cancer. Metformin has been studied for its influences in prevention and treatment of cancer through multiple mechanisms such as microRNA (miR) regulation. Alteration in the expression of miRs by metformin may play an important role in the treatment of various cancers. MiRs are single-stranded RNAs that are involved in gene regulation. By binding to the 3'UTR of target mRNAs, miRs influence protein levels. Irregularities in the expression of miRs that control the expression of oncogenes and tumor suppressor genes are associated with the onset and progression of cancer. Metformin may possess an effect on tumor prevention and progression by modifying miR expression and downstream pathways. Here, we summarize the effect of metformin on different types of cancer by regulating the expression of various miRs and the associated downstream molecules.

Prognostic value of microRNAs in pancreatic cancer: a meta-analysis

BACKGROUND

The prognostic impact of microRNA (miRNA) expression levels in pancreatic cancer (PC) has been estimated for years, but the outcomes are controversial and heterogeneous. Therefore, we comprehensively reviewed the evidence collected on miRNA expression in PC to determine this effect.

RESULTS

PC patients with high miR-21 (HR=2.61, 95%CI=1.68-4.04), miR-451a (HR=2.23, 95%CI=1.23-4.04) or miR-1290 (HR=1.43, 95%CI=1.04-1.95) levels in blood had significantly poorer OS (P<0.05). Furthermore, PC patients with high miR-10b (HR=1.73, 95%CI=1.09-2.76), miR-17-5p (HR=1.91, 95%CI=1.30-2.80), miR-21 (HR=1.90, 95%CI=1.61-2.25), miR-23a (HR=2.18, 95%CI=1.52-3.13), miR-155 (HR=2.22, 95%CI=1.27-3.88), miR-203 (HR=1.65, 95%CI=1.14-2.40), miR-221 (HR=1.72, 95%CI=1.08-2.74), miR-222 levels (HR=1.72, 95%CI=1.02-2.91) or low miR-29c (HR=1.39, 95%CI=1.08-1.79), miR-126 (HR=1.55, 95%CI=1.23-1.95), miR-218 (HR=2.62, 95%CI=1.41-4.88) levels in tissues had significantly shorter OS (P<0.05).

CONCLUSIONS

In summary, blood miR-21, miR-451a, miR-1290 and tissue miR-10b, miR-17-5p, miR-21, miR-23a, miR-29c, miR-126, miR-155, miR-203, miR-218, miR-221, miR-222 had significant prognostic value.

METHODS

We searched PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews to recognize eligible studies, and 57 studies comprising 5445 PC patients and 15 miRNAs were included to evaluate the associations between miRNA expression levels and overall survival (OS) up to June 1, 2019. Summary hazard ratios (HR) with 95% confidence intervals (CI) were calculated to assess the effect.

The Pancreatic Cancer-Initiating Cell Marker CD44v6 Affects Transcription, Translation, and Signaling: Consequences for Exosome Composition and Delivery

Pancreatic cancer-initiating cells (PaCIC) express CD44v6 and Tspan8. A knockdown (kd) of these markers hinders the metastatic capacity, which can be rescued, if the cells are exposed to CIC-exosomes (TEX). Additional evidence that CD44v6 regulates Tspan8 expression prompted us to explore the impact of these PaCIC markers on nonmetastatic PaCa and PaCIC-TEX. We performed proteome, miRNA, and mRNA deep sequencing analyses on wild-type, CD44v6kd, and Tspan8kd human PaCIC and TEX. Database comparative analyses were controlled by qRT-PCR, Western blot, flow cytometry, and confocal microscopy. Transcriptome analysis of CD44 versus CD44v6 coimmunoprecipitating proteins in cells and TEX revealed that Tspan8, several signal-transducing molecules including RTK, EMT-related transcription factors, and proteins engaged in mRNA processing selectively associate with CD44v6 and that the membrane-attached CD44 intracytoplasmic tail supports Tspan8 and NOTCH transcription. Deep sequencing uncovered a CD44v6 contribution to miRNA processing. Due to the association of CD44v6 with Tspan8 in internalization prone tetraspanin-enriched membrane domains (TEM) and the engagement of Tspan8 in exosome biogenesis, most CD44v6-dependent changes were transferred into TEX such that the input of CD44v6 to TEX activities becomes largely waved in both a CD44v6kd and a Tspan8kd. Few differences between CD44v6kd- and Tspan8kd-TEX rely on CD44v6 being also recovered in non-TEM derived TEX, highlighting distinct TEX delivery from individual cells that jointly account for TEX-promoted target modulation. This leads us to propose a model in which CD44v6 strongly supports tumor progression by cooperating with signaling molecules, altering transcription of key molecules, and through its association with the mRNA processing machinery. The association of CD44v6 with Tspan8, which plays a crucial role in vesicle biogenesis, promotes metastases by transferring CD44v6 activities into TEM and TEM-independently derived TEX. Further investigations of the lead position of CD44v6 in shifting metastasis-promoting activities into CIC-TEX may offer a means of targeting TEX-CD44v6 in therapeutic applications.

c-MYB and DMTF1 in Cancer

The c-Myb gene encodes a transcription factor that regulates cell proliferation, differentiation, and apoptosis through protein-protein interaction and transcriptional regulation of signaling pathways. The protein is frequently overexpressed in human leukemias, breast cancers, and other solid tumors suggesting that it is a bona fide oncogene. c-MYB is often overexpressed by translocation in human tumors with t(6;7)(q23;q34) resulting in c-MYB-TCRβ in T cell ALL, t(X;6)(p11;q23) with c-MYB-GATA1 in acute basophilic leukemia, and t(6;9)(q22-23;p23-24) with c-MYB-NF1B in adenoid cystic carcinoma. Antisense oligonucleotides to c-MYB were developed to purge bone marrow cells to eliminate tumor cells in leukemias. Recently, small molecules that inhibit c-MYB activity have been developed to disrupt its interaction with p300. The Dmp1 (cyclin D binding myb-like protein 1; Dmtf1) gene was isolated through its virtue for binding to cyclin D2. It is a transcription factor that has a Myb-like repeat for DNA binding. The Dmtf1 protein directly binds to the Arf promoter for transactivation and physically interacts with p53 to activate the p53 pathway. The gene is hemizygously deleted in 35-42% of human cancers and is associated with longer survival. The significances of aberrant expression of c-MYB and DMTF1 proteins in human cancers and their clinical significances are discussed.

Expression of microRNA-150 and its Target Gene IGF2BP1 in Human Osteosarcoma and their Clinical Implications

Previous study revealed that microRNA (miR)-150 might function as a tumor suppressor in osteosarcoma partially by targeting Insulin-Like Growth Factor 2 mRNA-Binding Protein 1 (IGF2BP1). The aim of this study was to investigate the clinical significance of miR-150-IGF2BP1 axis in human osteosarcoma which remains unclear. At first, expression levels of miR-150, and IGF2BP1 mRNA and protein in 20 osteosarcoma and matched adjacent noncancerous tissues were respectively detected by quantitative real-time PCR and western blot analyses. Then, subcellular localization and expression pattern of IGF2BP1 protein in 100 osteosarcoma tissues were examined by immunohistochemistry. Associations of miR-150/IGF2BP1 expression with various clinicopathological features and patients’ prognosis were also statistically evaluated. As a result, miR-150 expression was significantly decreased, while IGF2BP1 mRNA and protein expression were dramatically increased in osteosarcoma tissues compared to matched adjacent noncancerous tissues (all P < 0.001). Immunostaining of IGF2BP1 protein was localized in cytoplasm of tumor cells in osteosarcoma tissues. Statistically, low miR-150 expression and/or high IGF2BP1 protein immunoreactive score were all significantly associated with high tumor grade, presence of metastasis and recurrence, as well as poor response to chemotherapy (all P < 0.05). Moreover, miR-150, IGF2BP1 and combined miR-150/IGF2BP1 expressions were all identified as independent prognostic factors for overall and disease-free survivals of osteosarcoma patients (all P < 0.05). In conclusion, our data suggest that miR-150 and its downstream target IGF2BP1 may be a crucial axis for the development, progression and patients’ prognosis of ostesarcoma. The newly identified miR-150/IGF2BP1 axis might be a novel potential therapeutic target for osteosarcoma treatment.

MicroRNA-150 suppresses triple-negative breast cancer metastasis through targeting HMGA2

Background

Growing evidence suggests that miR-150 plays an inhibitory role in various types of cancer. However, the function and underlying mechanisms of miR-150 in triple-negative breast cancer (TNBC) remain unknown.

Patients and methods

miR-150 expression was detected by qRT-PCR and ISH in TNBC tumor and adjacent normal breast tissues. miR-150 function was analyzed by wound healing and transwell assay in vitro and mouse lung metastasis model in vivo. mRNA microarray, qRT-PCR, western blotting and luciferase assay were used to identify the target gene of miR-150. HMGA2 over-expression plasmid was co-transfected with miR-150 to study the role of miR-150 through regulating HMGA2.

Results

We found that miR-150 was down-regulated in TNBC tumor tissues compared to corresponding adjacent, normal breast tissues, and was correlated with decreased lymph-node metastasis. Ectopic expression of miR-150 suppressed TNBC cell migration in vitro and metastasis in vivo. Mechanistic study revealed that miR-150 down-regulates HMGA2 by directly targeting its mRNA. Moreover, the suppression of cell migration caused by miR-150 is relieved by over-expression of HMGA2, suggesting that miR-150 inhibits migration of TNBC cells by down-regulating HMGA2.

Conclusion

This work indicates that the miR-150/HMGA2 axis may serve as a treatment marker in TNBC.

Oncogenomic disruptions in arsenic-induced carcinogenesis

Chronic exposure to arsenic affects more than 200 million people worldwide, and has been associated with many adverse health effects, including cancer in several organs. There is accumulating evidence that arsenic biotransformation, a step in the elimination of arsenic from the human body, can induce changes at a genetic and epigenetic level, leading to carcinogenesis. At the genetic level, arsenic interferes with key cellular processes such as DNA damage-repair and chromosomal structure, leading to genomic instability. At the epigenetic level, arsenic places a high demand on the cellular methyl pool, leading to global hypomethylation and hypermethylation of specific gene promoters. These arsenic-associated DNA alterations result in the deregulation of both oncogenic and tumour-suppressive genes. Furthermore, recent reports have implicated aberrant expression of non-coding RNAs and the consequential disruption of signaling pathways in the context of arsenic-induced carcinogenesis. This article provides an overview of the oncogenomic anomalies associated with arsenic exposure and conveys the importance of non-coding RNAs in the arsenic-induced carcinogenic process.

Wnt/β-catenin pathway transactivates microRNA-150 that promotes EMT of colorectal cancer cells by suppressing CREB signaling

A hallmark of aberrant activation of the Wnt/β-catenin signaling pathway has been observed in most colorectal cancers (CRC), but little is known about the role of non-coding RNAs regulated by this pathway. Here, we found that miR-150 was the most significantly upregulated microRNA responsive to elevated of Wnt/β-catenin signaling activity in both HCT116 and HEK293T cells. Mechanistically, the β-catenin/LEF1 complex binds to the conserved TCF/LEF1-binding element in the miR-150 promoter and thereby transactivates its expression. Enforced expression of miR-150 in HCT116 cell line transformed cells into a spindle shape with higher migration and invasion activity. miR-150 markedly suppressed the CREB signaling pathway by targeting its core transcription factors CREB1 and EP300. Knockdown of CREB1 or EP300 and knockout of CREB1 by CRISPR/Cas9 phenocopied the epithelial-mesenchymal transition (EMT) observed in HCT116 cells in response to miR-150 overexpression. In summary, our data indicate that miR-150 is a novel Wnt effector that may significantly enhance EMT of CRC cells by targeting the CREB signaling pathway.

MicroRNA-150 suppresses cell proliferation and metastasis in hepatocellular carcinoma by inhibiting the GAB1-ERK axis

MicroRNA-150 (miR-150) is frequently dysregulated in cancer and is involved in carcinogenesis and cancer progression. In this study, we found that miR-150 was significantly downregulated in hepatocellular carcinoma (HCC) tissues compared to adjacent noncancerous tissues. Low levels of miR-150 were significantly associated with worse clinicopathological characteristics and a poor prognosis for patients with HCC. miR-150 overexpression inhibited cell proliferation, migration and invasion in vitro and tumor growth and metastasis in vivo. Further experiments indicated that Grb2-associated binding protein 1 (GAB1) was a direct target of miR-150 in HCC cells. In addition, GAB1 expression was increased in HCC tissues and inversely correlated with miR-150 levels. Knockdown of GAB1 mimicked the tumor-suppressive effects of miR-150 overexpression on HCC cells, whereas restoration of GAB1 expression partially abolished the inhibitory effects. Moreover, miR-150 overexpression decreased GAB1 expression, subsequently downregulated phospho-ERK1/2 and suppressed epithelial-mesenchymal-transition (EMT). These effects caused by miR-150 overexpression were alleviated by exogenous GAB1 expression. Taken together, this study demonstrates that miR-150 may be useful as a prognostic marker and that the identified miR-150-GAB1-ERK axis is a potential therapeutic target for HCC.

MicroRNA-150 attenuates hypoxia-induced excessive proliferation and migration of pulmonary arterial smooth muscle cells through reducing HIF-1α expression

Pulmonary arterial hypertension (PAH) is a progressive, fatal disease for which currently there is no curative therapy available. Pathologic changes in this disease involve excessive proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). However, the underlying role of miR-150 in PASMCs remains elusive. Here in this study, miR-150 down-regulation was observed in hypoxia-treated PASMCs. Restoration of miR-150 attenuates hypoxia-treated PASMC proliferation and migration. Luciferase reporter assay showed that miR-150 directly regulated expression of HIF-1α. Moreover, overexpression of HIF-1α impaired the suppressive effect of miR-150 on the proliferative and migratory capacities of PASMCs. Altogether, our findings indicate that miR-150 may exert inhibitory effects on excessive proliferation and migration of PASMCs through down-regulation of HIF-1α, providing new insights into the potential mechanisms of human PAH.

Long non-coding RNA linc00673 regulated non-small cell lung cancer proliferation, migration, invasion and epithelial mesenchymal transition by sponging miR-150-5p

Background

The function of a new long non-coding RNA linc00673 remains unclear. While identified as an oncogenic player in non-small cell lung cancer (NSCLC), linc00673 was found to be anti-oncogenic in pancreatic ductal adenocarcinoma (PDAC). However whether linc00673 regulated malignancy and epithelial mesenchymal transition (EMT) has not been characterized.

Methods

Cell proliferation was assessed using CCK-8 and EdU assays, and cell migration and invasion were assessed using scratch assays and transwell invasion assays. Epithelial mesenchymal transition was examined using western blot, qRT-PCR and immunofluorescence staining. Interaction between miRNA and linc00673 was determined using luciferase reporter assays. In vivo experiments were performed to assess tumor formation. In addition, the expression data of NSCLC specimens of TCGA and patient survival data were utilized to explore the prognostic significance of linc00673.

Results

In the present study, we found high linc00673 expression was associated with poor prognosis of NSCLC patients. In vitro experiments showed linc00673 knockdown reversed TGF-β induced EMT, and miR-150-5p was predicted to target linc00673 through bioinformatics tools. Overexpression of miR-150-5p suppressed lin00673’s expression while inhibition of miR-150-5p led to significant upregulation of lin00673, suggesting that linc00673 could be negatively regulated by miR-150-5p, which was further confirmed by the inverse correlation between linc00673 and miR-150-5p in NSCLC patients’ specimen. Furthermore, we proved that miR-150-5p could directly target linc00673 through luciferase assay, so linc00673 could sponge miR-150-5p and modulate the expression of a key EMT regulator ZEB1 indirectly. In addition, miR-150-5p inhibition abrogated linc00673 silence mediated proliferation, migration, invasion and EMT suppressing effect. Moreover, the inhibition of linc00673 significantly attenuated the tumorigenesis ability of A549 cells in vivo.

Conclusions

We validated linc00673 as a novel oncogenic lncRNA and demonstrated the molecular mechanism by which it promotes NSCLC, which will advance our understanding of its clinical significance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0685-9) contains supplementary material, which is available to authorized users.

MicroRNA-150 functions as an antioncogenic regulator in osteosarcoma

Numerous studies have demonstrated that microRNAs (miRs) are involved in several physiological and pathological processes, and participate in cancer initiation and progression. The abnormal expression of miR-150 has been reported in numerous types of human cancer. However, at present there are no studies of miR-150 in osteosarcoma (OS). Reverse transcription-quantitative polymerase chain reaction was performed to measure miR-150 expression levels in OS tissues and cell lines. Subsequent to transfection with miR-150 mimics or zinc finger E-box binding homeobox 1 (ZEB1) small interfering RNA, an MTT assay, Transwell migration and invasion assays, western blotting and a Dual-Luciferase reporter assay were performed in human OS cell lines. The present study revealed that miR-150 was downregulated in OS tissues and cell lines. In addition, the expression levels of miR-150 were correlated with the clinical stage and degree of distant metastasis of patients with OS. In addition, ZEB1 was identified as a direct target of miR-150 in vitro. In conclusion, miR-150 targeted ZEB1 to function as an antioncogenic regulator in OS. These findings elucidated a novel underlying mechanism for the pathogenic process in OS carcinogenesis and progression, and may provide novel targeted therapeutic regimens for patients with OS.

Never let it go: Stopping key mechanisms underlying metastasis to fight pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive neoplasm, predicted to become the second leading cause of cancer-related deaths before 2030. This dismal trend is mainly due to lack of effective treatments against its metastatic behavior. Therefore, a better understanding of the key mechanisms underlying metastasis should provide new opportunities for therapeutic purposes. Genomic analyses revealed that aberrations that fuel PDAC tumorigenesis and progression, such as SMAD4 loss, are also implicated in metastasis. Recently, microRNAs have been shown to play a regulatory role in the metastatic behavior of many tumors, including PDAC. In particular, miR-10 and miR-21 have appeared as master regulators of the metastatic program, while members of the miR-200 family are involved in the epithelial-to-mesenchymal switch, favoring cell migration and invasiveness. Several studies have also found a close relationship between cancer stem cells (CSCs) and biological features of metastasis, and the CSC markers ALDH1, ABCG2 and c-Met are expressed at high levels in metastatic PDAC cells. Emerging evidence reveals that exosomes are involved in the modulation of the tumor microenvironment and can initiate PDAC pre-metastatic niche formation in the liver and lungs. In this review, we provide an overview of the role of all these pivotal factors in the metastatic behavior of PDAC, and discuss their potential exploitation in the clinic to improve current therapeutics and identify new drug targets.

MUC4 mucin- a therapeutic target for pancreatic ductal adenocarcinoma

INTRODUCTION

Pancreatic cancer (PC) is characterized by mucin overexpression. MUC4 is the most differentially overexpressed membrane-bound mucin that plays a functional role in disease progression and therapy resistance. Area covered: We describe the clinicopathological significance of MUC4, summarize mechanisms contributing to its deregulated expression, review preclinical studies aimed at inhibiting MUC4, and discuss how MUC4 overexpression provides opportunities for developing targeted therapies. Finally, we discuss the challenges for developing MUC4-based therapeutics, and identify areas where efforts should be directed to effectively exploit MUC4 as a therapeutic target for PC. Expert opinion: Studies demonstrating that abrogation of MUC4 expression reduces proliferation and metastasis of PC cells and enhances sensitivity to therapeutic agents affirm its utility as a therapeutic target. Emerging evidence also supports the suitability of MUC4 as a potential immunotherapy target. However, these studies have been limited to in vitro, ex vivo or in vivo approaches using xenograft tumors in immunodeficient murine models. For translational relevance, MUC4-targeted therapies should be evaluated in murine models with intact immune system and accurate tumor microenvironment. Additionally, future studies evaluating MUC4 as a target for immunotherapy must entail characterization of immune response in PC patients and investigate its association with immunosuppression and survival.

MicroRNA-150 targets ELK1 and modulates the apoptosis induced by ox-LDL in endothelial cells

Atherosclerosis, a chronic inflammatory disease, is the major cause of life-threatening complications such as myocardial infarction and stroke. Endothelial cells (ECs) apoptosis plays a vital role in the initiation and progression of atherosclerosis. Although a subset of microRNAs (miRNAs) have been identified as critical regulators of atherosclerosis, studies on their participation in endothelial apoptosis in atherosclerosis have been limited. In the current study, we show that miRNA-150 (miR-150) expression was substantially up-regulated during the oxidized low-density lipoprotein (ox-LDL)-induced apoptosis in human umbilical cord vein endothelial cells (HUVECs). Forced expression of miR-150 enhanced apoptosis in ECs, whereas inhibition of miR-150 could partly alleviate apoptotic cell death mediated by ox-LDL. Further analysis identified ELK1 as a direct target of miR-150, and ELK1 knockdown abolished the anti-apoptotic effect of miR-150 inhibitor. These findings reveal a novel role of miR-150 in endothelial apoptosis and indicate a therapeutic potential of miR-150 for endothelial dysfunction and atherosclerosis.

Endoplasmic reticulum stress enhances fibrosis through IRE1α-mediated degradation of miR-150 and XBP-1 splicing

ER stress results in activation of the unfolded protein response and has been implicated in the development of fibrotic diseases. In this study, we show that inhibition of the ER stress-induced IRE1α signaling pathway, using the inhibitor 4μ8C, blocks TGFβ-induced activation of myofibroblasts in vitro, reduces liver and skin fibrosis in vivo, and reverts the fibrotic phenotype of activated myofibroblasts isolated from patients with systemic sclerosis. By using IRE1α(-/-) fibroblasts and expression of IRE1α-mutant proteins lacking endoribonuclease activity, we confirmed that IRE1α plays an important role during myofibroblast activation. IRE1α was shown to cleave miR-150 and thereby to release the suppressive effect that miR-150 exerted on αSMA expression through c-Myb. Inhibition of IRE1α was also demonstrated to block ER expansion through an XBP-1-dependent pathway. Taken together, our results suggest that ER stress could be an important and conserved mechanism in the pathogenesis of fibrosis and that components of the ER stress pathway may be therapeutically relevant for treating patients with fibrotic diseases.

Hsa-miR-495 acts as a tumor suppressor gene in glioma via the negative regulation of MYB

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression at the post-transcriptional level. Previous studies have reported that there are causative links between the abnormal regulation of miRNAs and cancer development. Hsa‑miR‑495 has previously been demonstrated to be downregulated, and to function as a tumor suppressor, in numerous types of human cancer. However, the function and molecular mechanism of hsa‑miR‑495 in glioma remains unclear. In the current study, the expression and effects of hsa‑miR‑495 on glioma were evaluated. It was identified that the expression levels of hsa-miR-495 were downregulated in glioma tissues and cell lines. Furthermore, restoration of hsa-miR-495 inhibited glioma cell proliferation and invasion in vitro. Notably, a luciferase reporter assay revealed that hsa‑miR‑495 was able to directly target v‑myb avian myeloblastosis viral oncogene homolog (MYB) in glioma cells. In addition, an RNA interference assay indicated that MYB knockdown inhibited glioma cell proliferation and invasion in vitro. In conclusion, the results of the present study suggested that hsa‑miR‑495 may act as a tumor suppressor gene in glioma by directly inhibiting MYB expression, which may provide a novel therapeutic strategy for the treatment of glioma.

Are We Eating Our Way to Prostate Cancer-A Hypothesis Based on the Evolution, Bioaccumulation, and Interspecific Transfer of miR-150

MicroRNAs (miRNAs) are well established epigenetic modifiers. There is a lot of work being done to identify the evolutionary transfer of miRNAs both at intra- and interspecific levels. In this hypothesis-driven review, we have suggested a possible reason as to why miR-150 can be a promising diagnostic biomarker for prostate cancer using theories of evolution, bio-accumulation, and interspecific transfer of miRNAs.