The downregulation of miR-200c/141 promotes ZEB1/2 expression and gastric cancer progression

miR-200c targeting GLI3 inhibits cell proliferation and promotes apoptosis in non-small cell lung cancer cells

Lung cancer is a common malignant tumor with low cure rate. It has an easy recurrence and metastasis. This study explored whether miR-200c could regulate the biological behavior of non-small cell lung cancer cells through targeting GLI3. Luciferase reporter gene analysis was used to verify the interaction between miR-200c-3p and GLI3. miR-200c-3p and GLI3 were transiently overexpressed into A549 cells. The cell viability rate was detected by cell counting kit-8, cell invasion ability was detected with Transwell, cell apoptosis and cell cycle was determined by flow cytometry, and the expression of GLI3 was detected using quantitative polymerase chain reaction and Western blot, to verify the effect of the interaction between miR-200c-3p and GLI3 on the cell activities. miR-200c-3p overexpression could inhibit cell viability and invasion, promote apoptosis, induce G0/G1 arrest, and inhibit cell division. GLI3 overexpression could reverse the miR-200c-3p inhibition on cell cycle, reduce the number of cells in the G0/G1 phase and increase the number of cells in the S phase. miR-200c-3p overexpression in A549 cells could inhibit cell viability and invasion, and promote apoptosis. miR-200c-3p could target GLI3 to regulate cell cycle and inhibit cell proliferation.

miR-141-3p attenuates RSL3-induced ferroptosis and intestinal epithelial-mesenchymal transition via directly inhabits ZEB1 in intestinal Behçet's syndrome

The aims of this study were to investigate whether the ferroptosis is involved in intestinal Behçet's syndrome (IBS), and to identify if miR-141-3p could attenuate RAS-selective lethal 3 (RSL3)-induced ferroptosis and intestinal epithelial to mesenchymal transition (EMT) via directly inhabits zinc fnger E-box binding homeobox 1 (ZEB1). The expressions of ferroptosis-related proteins in the intestinal tissues of patients with IBS were investigated by immunohistochemistry and quantitative real-time PCR (qRT-PCR). Malondialdehyde (MDA) contents of the intestinal tissues and cells were detected. Serum from IBS patients and RSL3 were co-cultured with intestinal epithelial cells in vitro. In order to investigate whether RSL3-induced ferroptosis can be ameliorated by miR-141-3p, the intestinal epithelial cells were firstly stimulated with RSL3 and then incubated with miR-141-3p mimics. Western blot was used to measure the expression of EMT and ferroptosis-related proteins. Expression of GPX4 (22.51% ± 2.05%, 51.75% ± 3.47%, t =  - 7.77, p = 0.000) and xCT (17.49% ± 1.57%, 28.73% ± 1.75%, t =  - 4.38, p = 0.003) were significantly lower in intestinal mucosal tissues of patients with IBS compared with HC group. Compared with the HC samples, the IBS specimens had significantly higher MDA (t = 4.32, p = 0.01). Moreover, the relative mRNA levels of ferritin light chain (FTL) (t = 4.07, p = 0.02) and ferritin heavy chain (FTH) (t = 8.82, p = 0.001) in the intestinal tissues were significant higher in IBS patients than in HC group. Serum from IBS patients could induce intestinal epithelial cell ferroptosis in vitro. Moreover, miR-141-3p could attenuate intestinal epithelial cell ferroptosis-induced by RSL3 and intestinal EMT via targeting ZEB1 in vitro. Ferroptosis were induced in patients with IBS. Moreover, the serum from IBS patients could induce ferroptosis in vitro. miR-141-3p could attenuate intestinal epithelial cell ferroptosis and intestinal EMT via targeting ZEB1. Therefore, miR-141-3p may open new avenues for the treatment of IBS in the future. Key Points • Ferroptosis in IBS is first reported in this study. • In this study, we explored that the serum from IBS patients could induce ferroptosis in vitro and miR-141-3p could attenuate intestinal epithelial cell ferroptosis and intestinal EMT via targeting ZEB1.

miRNA/epithelial-mesenchymal axis (EMT) axis as a key player in cancer progression and metastasis: A focus on gastric and bladder cancers

The metastasis a major hallmark of tumors that its significant is not only related to the basic research, but clinical investigations have revealed that majority of cancer deaths are due to the metastasis. The metastasis of tumor cells is significantly increased due to EMT mechanism and therefore, inhibition of EMT can reduce biological behaviors of tumor cells and improve the survival rate of patients. One of the gaps related to cancer metastasis is lack of specific focus on the EMT regulation in certain types of tumor cells. The gastric and bladder cancers are considered as two main reasons of death among patients in clinical level. Herein, the role of EMT in regulation of their progression is evaluated with a focus on the function of miRNAs. The inhibition/induction of EMT in these cancers and their ability in modulation of EMT-related factors including ZEB1/2 proteins, TGF-β, Snail and cadherin proteins are discussed. Moreover, lncRNAs and circRNAs in crosstalk of miRNA/EMT regulation in these tumors are discussed and final impact on cancer metastasis and response of tumor cells to the chemotherapy is evaluated. Moreover, the impact of miRNAs transferred by exosomes in regulation of EMT in these cancers are discussed.

Dysregulation of miRNA expression in patients with chronic myelogenous leukemia at diagnosis: a systematic review

Aim: The present systematic review aimed to explore miRNAs as a potential biomarker for early diagnosis of chronic myeloid leukemia (CML). Materials & methods: A systematic search was conducted in three electronic databases, including Web of Science, Scopus and PubMed, to obtain relevant articles investigating the alteration of miRNA expression in patients with CML. Results: The authors found miRNAs whose expression changes are effective in the induction of CML disease. Among them, miR-21 and miR-155 were identified as the most common miRNAs with increased expression and miR-150 and miR-146 as the most common miRNAs with decreased expression. Conclusion: miRNAs can be used as an indicator for the early detection and treatment of CML phase.

Unleashing the pathological imprinting of cancer in autoimmunity: Is ZEB1 the answer?

The intriguing scientific relationship between autoimmunity and cancer immunology have been traditionally indulged to throw spotlight on novel pathological targets. Understandably, these "slowly killing" diseases are on the opposite ends of the immune spectrum. However, the immune regulatory mechanisms between autoimmunity and cancer are not always contradictory and sometimes mirror each other based on disease stage, location, and timepoint. Moreover, the blockade of immune checkpoint molecules or signalling pathways that unleashes the immune response against cancer is being leveraged to preserve self-tolerance and treat many autoimmune disorders. Therefore, understanding the common crucial factors involved in cancer is of paramount importance to paint the autoimmune disease spectrum and validate novel drug candidates. In the current review, we will broadly describe how ZEB1, or Zinc-finger E-box Binding Homeobox 1, reinforces immune exhaustion in cancer or contributes to loss of self-tolerance in auto-immune conditions. We made an effort to exchange information about the molecular pathways and pathological responses (immune regulation, cell proliferation, senescence, autophagy, hypoxia, and circadian rhythm) that can be regulated by ZEB1 in the context of autoimmunity. This will help untwine the intricate and closely postured pathogenesis of ZEB1, that is less explored from the perspective of autoimmunity than its counterpart, cancer. This review will further consider several approaches for targeting ZEB1 in autoimmunity.

miRNA-381-3p Functions as a Tumor Suppressor to Inhibit Gastric Cancer by Targeting Fibroblast Growth Factor Receptor-2

Objectives: MicroRNAs possess essential effects on gastric cancer (GC), whereas the underlying mechanisms have not been fully uncovered. The present work focused on investigating the role of miR-381-3p in GC cellular processes and the possible mechanisms. Materials and Methods: miR-381-3p levels within GC tissues and cells were measured through quantitative real-time polymerase chain reaction (qRT-PCR). This study measured cell proliferation, apoptosis, and metastasis through EdU, colony formation, flow cytometry, and Transwell assays separately. TargetScan was adopted to predict the miR-381-3p targets, whereas luciferase reporter assay was adopted for confirmation. Results: miR-381-3p levels were decreased, whereas fibroblast growth factor receptor-2 (FGFR2) expression was increased in GC. miR-381-3p upregulation inhibited proliferation, migration, and invasion and it promoted the apoptosis of GC cells. Further, FGFR2 overexpression partly reversed the miR-381-3p-mediated impacts on GC cellular processes. Conclusions: This study provides an experimental basis, suggesting the potential of using miR-381-3p as the novel marker for GC. Clinical Trial Registration number: 2020-05.

MiR-183-5p promotes renal cell carcinoma metastasis by targeting TET1

Ten-eleven translocation 1 (TET1) is a member of the DNA demethylase family that regulates the methylation level of the genome. Dysregulation of TET1 in renal cell carcinoma (RCC) may be associated with RCC progression, but the mechanism of TET1 down-regulation in RCC is not yet known. MiR-183-5p is up-regulated in various tumor tissues and acts as an oncogene. We used Transwell and wound healing assays to test cell invasion and migration. To investigate DNA methylation, we used dot blot, which indicates TET1 enzyme activity. We verified the binding of miR-183-5p and TET1 3'-UTR (untranslated region) using dual-luciferase reporter assay. Our study demonstrated, for the first time, that miR-183-5p can directly repress TET1 expression in RCC. We observed a significant decrease in TET1 expression in RCC specimens, as reported in the literature, and a significant decrease in the concentration of 5hmC in RCC. By aligning the microRNA with a database and using the luciferase reporter gene method, we found that miR-183-5p can inhibit luciferase activity by binding to 453-459 bp of TET1 3'-UTR, leading to inhibition of TET1 expression. Furthermore, down-regulation of TET1 inhibited miR-200c expression and promoted RCC cell invasion and migration. Our findings suggest that in RCC, increased expression of miR-183-5p inhibits the expression of TET1, which in turn inhibits the expression of miR-200c and E-cadherin, both of which are associated with cell adhesion. This leads to the promotion of cell invasion and migration.

Functional mechanism and clinical implications of miR-141 in human cancers

Cancer is caused by the abnormal proliferation of local tissue cells under the control of many oncogenic factors. MicroRNAs (miRNAs) are a class of evolutionarily conserved, approximately 22-nucleotide noncoding small RNAs that influence transcriptional regulationby binding to the 3'-untranslated region of target messenger RNA. As a member of the miRNA family, miR-141 acts as a suppressor or an oncomiR in various cancers and regulates cancer cell proliferation, apoptosis, invasion, and metastasis through a variety of signaling pathways, such as phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) and constitutive activation of nuclear factor-κB (NF-κB). Target gene validation and pathway analysis have provided mechanistic insight into the role of this miRNA in different tissues. This review also outlines novel findings that suggest miR-141 may be useful as a noninvasive biomarker and as a therapeutic target in several cancers.

Long non-coding RNA FAM83A antisense RNA 1 (lncRNA FAM83A-AS1) targets microRNA-141-3p to regulate lung adenocarcinoma cell proliferation, migration, invasion, and epithelial-mesenchymal transition progression

The current paper investigates how long non-coding RNA (lncRNA) FAM83A antisense RNA 1 (lncRNA FAM83A-AS1) affected the epithelial-mesenchymal transformation (EMT), growth, invasion and migration of lung adenocarcinoma (LUAD) via targeting miRNA-141-3p. The GEPIA and ENCORI databases were used to analyze differences in lncRNA FAM83A-AS1 levels within LUAD samples. FAM83A-AS1 and miR-141-3p levels were assessed using qRT-PCR among 30 LUAD samples and surrounding normal tissues. In addition, we analyzed how FAM83A-AS1 affected proliferation, invasion, migration, and EMT processes of LUAD cells by targeting miR-141-3p through EdU, CCK-8 assay, scratch assay, transwell migration and invasion assay, immunofluorescence (IF) staining and WB assay. MicroRNAs targeting FAM83A-AS1 were screened using AnnoLnc2 and identified by RT-qPCR. Dual-luciferase assays were utilized to evaluate the connection between FAM83A-AS1 and miR-141-3p. FAM83A-AS1 expression was remarkably raised in lung cancer cells and tissue samples; however, miR-141-3p level markedly reduced relative to healthy samples. FAM83A-AS1 silencing suppressed EMT, growth, invasion and migration of LUAD cells. MiR-141-3p was the possible FAM83A-AS1 binding target negatively associated with FAM83A-AS1. The miR-141-3p inhibitor partly abolished the FAM83A-AS1 knockdown-induced inhibition on EMT, cell growth, invasion and migration in LUAD cells. In addition, miR-141-3p down-regulation abolished the inhibition of E-box-bound zinc finger protein 1 and 2 protein production following FAM83A-AS1 knockdown. According to our results, FAM83A-AS1/miR-141-3p axis plays an important role in LUAD occurrence and development. FAM83A-AS1 sponged miR-141-3p to down-regulate the level of the latter within LUAD and thereby encouraging LUAD development and suggesting a possible novel therapeutic approach for LUAD.

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

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

Overview of host miRNA properties and their association with epigenetics, long non-coding RNAs, and Xeno-infectious factors

MicroRNA-derived structures play impressive roles in various biological processes. So dysregulation of miRNAs can lead to different human diseases. Recent studies have extended our comprehension of the control of miRNA function and features. Here, we overview some remarkable miRNA properties that have potential implications for the miRNA functions, including different variants of a miRNA called isomiRs, miRNA arm selection/arm switching, and the effect of these factors on miRNA target selection. Besides, we review some aspects of miRNA interactions such as the interaction between epigenetics and miRNA (different miRNAs and their related processing enzymes are epigenetically regulated by multiple DNA methylation enzymes. moreover, DNA methylation could be controlled by diverse mechanisms related to miRNAs), direct and indirect crosstalk between miRNA and lnc (Long Non-Coding) RNAs as a further approach to conduct intercellular regulation called "competing endogenous RNA" (ceRNA) that is involved in the pathogenesis of different diseases, and the interaction of miRNA activities and some Xeno-infectious (virus/bacteria/parasite) factors, which result in modulation of the pathogenesis of infections. This review provides some related studies to a better understanding of miRNA involvement mechanisms and overcoming the complexity of related diseases that may be applicable and useful to prognostic, diagnostic, therapeutic purposes and personalized medicine in the future.

MiRNA-200C expression in Fanconi anemia pathway functionally deficient lung cancers

The Fanconi Anemia (FA) pathway is essential for human cells to maintain genomic integrity following DNA damage. This pathway is involved in repairing damaged DNA through homologous recombination. Cancers with a defective FA pathway are expected to be more sensitive to cross-link based therapy or PARP inhibitors. To evaluate downstream effectors of the FA pathway, we studied the expression of 734 different micro RNAs (miRNA) using NanoString nCounter miRNA array in two FA defective lung cancer cells and matched control cells, along with two lung tumors and matched non-tumor tissue samples that were deficient in the FA pathway. Selected miRNA expression was validated with real-time PCR analysis. Among 734 different miRNAs, a cluster of microRNAs were found to be up-regulated including an important cancer related micro RNA, miR-200C. MiRNA-200C has been reported as a negative regulator of epithelial-mesenchymal transition (EMT) and inhibits cell migration and invasion by promoting the upregulation of E-cadherin through targeting ZEB1 and ZEB2 transcription factors. miRNA-200C was increased in the FA defective lung cancers as compared to controls. AmpliSeq analysis showed significant reduction in ZEB1 and ZEB2 mRNA expression. Our findings indicate the miRNA-200C potentially play a very important role in FA pathway downstream regulation.

Molecular Signature of Extracellular Vesicular Small Non-Coding RNAs Derived from Cerebrospinal Fluid of Leptomeningeal Metastasis Patients: Functional Implication of miR-21 and Other Small RNAs in Cancer Malignancy

Simple Summary

Leptomeningeal metastasis (LM) is a lethal complication in which cancer metastasizes to the meninges. Currently, there are neither definitive treatments nor diagnosis methods for LM patients. In this study, we suggest the examination of small non-coding RNA (smRNA) populations of extracellular vesicles (EVs) derived from the cerebrospinal fluid (CSF) as a potential vehicle for diagnosis and treatment strategies. Systemic and quantitative analysis of smRNA subpopulations from LM CSF EVs showed unique expression patterns between LM patients and healthy donors. In addition, LM CSF EVs smRNAs appeared to be associated with LM pathogenesis suggesting they may be viable targets for novel diagnostic and treatment strategies.

Abstract

Leptomeningeal metastasis (LM) is a fatal and rare complication of cancer in which the cancer spreads via the cerebrospinal fluid (CSF). At present, there is no definitive treatment or diagnosis for this deleterious disease. In this study, we systemically and quantitatively investigated biased expression of key small non-coding RNA (smRNA) subpopulations from LM CSF extracellular vesicles (EVs) via a unique smRNA sequencing method. The analyzed subpopulations included microRNA (miRNA), Piwi-interacting RNA (piRNA), Y RNA, small nuclear RNA (snRNA), small nucleolar RNAs (snoRNA), vault RNA (vtRNA), novel miRNA, etc. Here, among identified miRNAs, miR-21, which was already known to play an essential oncogenic role in tumorigenesis, was thoroughly investigated via systemic biochemical, miR-21 sensor, and physiological cell-based approaches, with the goal of confirming its functionality and potential as a biomarker for the pathogenesis and diagnosis of LM. We herein uncovered LM CSF extravesicular smRNAs that may be associated with LM-related complications and elucidated plausible pathways that may mechanistically contribute to LM progression. In sum, the analyzed smRNA subpopulations will be useful as targets for the development of therapeutic and diagnostic strategies for LM and LM-related complications.

Competing Endogenous RNA Networks in the Epithelial to Mesenchymal Transition in Diffuse-Type of Gastric Cancer

Simple Summary

The diffuse-type of gastric cancer is associated with epithelial to mesenchymal transition. Loss of E-cadherin expression is the hallmark of this process and is largely due to the upregulation of the transcription factors ZEB1/2, Snail, Slug, and Twist1/2. However, miRNA and lncRNAs can also participate through these transcription factors which directly target E-cadherin. The competing endogenous RNA (ceRNA) network hypothesis state that lncRNA can sponge the miRNA pool that targets these transcripts. Based on the lack of said networks in the epithelial to mesenchymal transition, we performed a prediction analysis that resulted in novel ceRNA networks which will expand our knowledge of the molecular basis of the diffuse-type of gastric cancer.

Abstract

The diffuse-type of gastric cancer (DGC), molecularly associated with epithelial to mesenchymal transition (EMT), is increasing in incidence. Loss of E-cadherin expression is the hallmark of the EMT process and is largely due to the upregulation of the EMT-inducing transcription factors ZEB1/2, Snail, Slug, and Twist1/2. However, ncRNA, such as miRNA and lncRNAs, can also participate in the EMT process through the direct targeting of E-cadherin and other EMT-inducing transcription factors. Additionally, lncRNA can sponge the miRNA pool that targets these transcripts through competing endogenous RNA (ceRNA) networks. In this review, we focus on the role of ncRNA in the direct deregulation of E-cadherin, as well as EMT-inducing transcription factors. Based on the relevance of the ceRNA network hypothesis, and the lack of said networks in EMT, we performed a prediction analysis for all miRNAs and lncRNAs that target E-cadherin, as well as EMT-inducing transcription factors. This analysis resulted in novel predicted ceRNA networks for E-cadherin and EMT-inducing transcription factors (EMT-TFs), as well as the expansion of the molecular basis of the DGC.

Circular RNA circ-PVT1 contributes to paclitaxel resistance of gastric cancer cells through the regulation of ZEB1 expression by sponging miR-124-3p

Gastric cancer (GC) is the fifth most commonly diagnosed malignancy. Paclitaxel (PTX) is an effective first-line chemotherapy drug in GC treatment, but the resistance of PTX attenuates the therapeutic effect. Circular RNA circ-PVT1 can exert the oncogenic effect in GC. But the function of circ-PVT1 involved in PTX resistance of GC is still unknown. In the present study, the expression levels of circ-PVT1, miR-124-3p and ZEB1 in PTX-resistant GC tissues and cells were detected by quantitative real-time polymerase chain reaction (RT-qPCR). PTX resistance in PTX-resistant cells was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The protein levels of Zinc finger E-box binding homeobox 1 (ZEB1), P-glycoprotein (P-gp) and glutathione S-transferase (GST-π) were detected by Western blot assay. Cell apoptosis and invasion were measured in PTX-resistant cells by flow cytometry and transwell invasion assays, severally. The interaction between miR-124-3p and circ-PVT1 or ZEB1 was predicted by starBase software, and then verified by the dual-luciferase reporter assay. The role of circ-PVT1 in PTX resistance of GC in vivo was measured by xenograft tumor model. Our results showed that circ-PVT1 expression was up-regulated in PTX-resistant GC tissues and cells. Circ-PVT1 down-regulation enhanced PTX sensitivity in PTX-resistant GC cells by negatively regulating miR-124-3p. ZEB1 served as a direct target of miR-124-3p. Circ-PVT1 enhanced ZEB1 expression by sponging miR-124-3p. Circ-PVT1 knockdown increased PTX sensitivity of GC in vivo. Taken together, our studies disclosed that circ-PVT1 facilitated PTX resistance by up-regulating ZEB1 mediated via miR-124-3p, suggesting an underlying therapeutic strategy for GC.

Helicobacter pylori Eradication Can Reverse the Methylation-Associated Regulation of miR-200a/b in Gastric Carcinogenesis

Background/Aims

Epigenetic change is one of the mechanisms that regulates the expression of microRNAs (miRNAs) and is known to play a role in Helicobacter pylori-associated gastric carcinogenesis. We aimed to evaluate the epigenetic changes of miR-200a/b in H. pylori-associated gastric carcinogenesis and restoration after eradication.

Methods

The expression and methylation levels of miR-200a/b were evaluated in gastric cancer (GC) cell lines, human gastric mucosa of H. pylori-negative and -positive controls, and H. pylori-positive GC patients. Next, the changes in the expression and methylation levels of miR-200a/b were compared between H. pylori-eradication and H. pylori-persistence groups at 6 months. Real-time reverse transcription-polymerase chain reaction was conducted to investigate the miRNA expression levels, and MethyLight was performed to assess the methylation levels.

Results

In the GC cell lines, the level of miR-200a/b methylation decreased and the level of expression increased after demethylation. In the human gastric mucosa, the miR-200a/b methylation levels increased in the following group order: H. pylori-negative control group, H. pylori-positive control group, and H. pylori-positive GC group. Conversely, the miR-200a/b expression levels decreased in the same order. In the H. pylori-persistence group, no significant changes were observed in the methylation and expression levels of miR-200a/b after 6 months, whereas the level of methylation decreased and the level of expression of miR-200a/b increased significantly 6 months in the H. pylori-eradication group.

Conclusions

Epigenetic alterations of miR-200a/b may be implicated in H. pylori-induced gastric carcinogenesis. This field defect for cancerization is suggested to be improved by H. pylori eradication.

MicroRNAs and Their Influence on the ZEB Family: Mechanistic Aspects and Therapeutic Applications in Cancer Therapy

Molecular signaling pathways involved in cancer have been intensively studied due to their crucial role in cancer cell growth and dissemination. Among them, zinc finger E-box binding homeobox-1 (ZEB1) and -2 (ZEB2) are molecules that play vital roles in signaling pathways to ensure the survival of tumor cells, particularly through enhancing cell proliferation, promoting cell migration and invasion, and triggering drug resistance. Importantly, ZEB proteins are regulated by microRNAs (miRs). In this review, we demonstrate the impact that miRs have on cancer therapy, through their targeting of ZEB proteins. MiRs are able to act as onco-suppressor factors and inhibit the malignancy of tumor cells through ZEB1/2 down-regulation. This can lead to an inhibition of epithelial-mesenchymal transition (EMT) mechanism, therefore reducing metastasis. Additionally, miRs are able to inhibit ZEB1/2-mediated drug resistance and immunosuppression. Additionally, we explore the upstream modulators of miRs such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as these regulators can influence the inhibitory effect of miRs on ZEB proteins and cancer progression.

miR-144-3p increases radiosensibility of gastric cancer cells by targeting inhibition of ZEB1

PURPOSE

This study set out to probe into the effect and mechanism of miR-144-3p on radiosensitivity of gastric cancer (GC) cells.

METHODS

Cancer tissue and paracancerous tissue of GC patients admitted to our hospital were collected, their miR-144-3p expression was tested, GC cells were transfected, and survival and biological behavior of those cells under radiation were detected.

RESULTS

After detection, miR-144-3p expression was down-regulated in GC tissue, while ZEB1 was up-regulated. There was no remarkable difference in the survival fraction of cells in each group before receiving radiation, but that of tumor cells decreased obviously (p < 0.05) after radiation exposure. Survival fraction of cells overexpressing miR-144-3p or silencing ZEB1 decreased more obviously, while the inhibition of miR-144-3p or overexpressing ZEB1 was weaker. Biological behavior of cells under 6 Gy radiation was detected. It was found that miR-144-3p overexpression or silencing ZEB1 dramatically inhibited the proliferation activity of GC cells under 6 Gy radiation, increased the levels of pro-apoptotic Bax and caspase-3 proteins (p < 0.05) and decreased the anti-apoptotic protein Bcl-2 level (p < 0.05), resulting in an increase in the apoptosis rate of cells. miR-144-3p was confirmed to be ZEB1 targeting site by dual luciferase report. Moreover, rescue experiments prove that it can increase the radiosensitivity of GC cells by regulating ZEB1 expression.

CONCLUSION

miR-144-3p expression was down-regulated in GC, and it can increase the radiosensitivity of those cells by inhibiting ZEB1 expression.

MicroRNA-141-5p Acts as a Tumor Suppressor via Targeting RAB32 in Chronic Myeloid Leukemia

MicroRNA-141-5p (miR-141-5p), an important member of the miR-200 family, has been reported to be involved in cellular proliferation, migration, invasion, and drug resistance in different kinds of human malignant tumors. However, the role and function of miR-141-5p in chronic myeloid leukemia (CML) are unclear. In this current study, we found that the level of miR-141-5p was significantly decreased in peripheral blood cells from CML patients compared with normal blood cells and human leukemic cell line (K562 cells) compared with normal CD34⁺ cells, but was remarkably elevated in patients after treatment with nilotinib or imatinib. Suppression of miR-141-5p promoted K562 cell proliferation and migration in vitro. As expected, overexpression of miR-141-5p weakened K562 cell proliferation, migration, and promoted cell apoptosis. A xenograft model in nude mice showed that overexpression of miR-141-5p markedly suppressed tumor growth in vivo. Mechanistic studies suggested that RAB32 was the potential target of miR-141-5p, and silencing of RAB32 suppressed the proliferation and migration of K562 cells and promoted cell apoptosis. Taken together, our study demonstrates that miR-141-5p plays an important role in the activation of K562 cells in vitro and may act as a tumor suppressor via targeting RAB32 in the development of CML.

Retracted Article: Circular RNA PTK2 modifies the progression and radiosensitivity in gastric cancer via miR-369-3p/ZEB1 axis

Gastric cancer (GC) is one of the common cancers worldwide. Emerging findings imply that aberrant expression of circular RNA_0003221 (circPTK2) is involved in GC. Nevertheless, the function of circPTK2 in GC needs more explanation. Profiles of circPTK2, microRNA (miR)-369-3p, and zinc finger E-box binding homeobox 1 (ZEB1) were determined by quantitative real-time polymerase chain reaction assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, and transwell assays were employed to estimate cell proliferation, apoptosis, and mobility in GC cells, respectively. Meanwhile, levels of ZEB1 and other indicated proteins were tested using western blot. Survival fraction was assessed utilizing clonogenic assay. Additionally, the role of circPTK2 in tumorigenesis was investigated via a xenograft tumor model. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were conducted to confirm the interrelation between miR-369-3p and circPTK2 or ZEB1. Levels of circPTK2 and ZEB1 were markedly augmented, but miR-369-3p was downregulated in GC tissues and cells. CircPTK2 depletion restrained cell growth, metastasis, and epithelial–mesenchymal transition, and promoted radiosensitivity in GC cells. And circPTK2 depletion reduced tumor growth and metastasis in vivo. Moreover, the effect of circPTK2 silencing on cellular phenotypes and radiosensitivity was regained by miR-369-3p inhibitor. Furthermore, upregulation of ZEB1 could overturn miR-369-3p mimic-induced effect on cell metastasis and radiosensitivity of GC cells. Mechanically, circPTK2 was a sponge of miR-369-3p to separate ZEB1. CircPTK2/miR-369-3p/ZEB1 axis modulated cell behaviors and radiosensitivity in GC; thus circPTK2 might serve as a promising target for GC therapy.

Circular RNA PTK2 regulates the cell proliferation, apoptosis, mobility and radiosensitivity via ZEB1 by sponging miR-369-3p in gastric cancer.

Suppression of α-methylacyl-coenzyme A racemase by miR200c inhibits prostate adenocarcinoma cell proliferation and migration

Overexpression of α-methylacyl-coenzyme A racemase (AMACR/P504S) is a major abnormality that has been observed in prostate cancer, whereas microRNA (miRNA/miR) 200c, is downregulated. The aim of the present study was to explore whether miR200c was able to exert any regulatory effects on AMACR. To meet this aim, bioinformatics analysis was performed to identify potential binding sites for miR200c in the 3′-untranslated region (3′-UTR) of AMACR. Recombinant adenoviral and dual reporter gene assays were designed to examine the binding of miR200c to the potential seed sequences in the AMACR 3′-UTR. Conventional reverse transcription (RT)-PCR, RT-quantitative (q)PCR and western blotting were also used to examine the regulatory effects of miR200c on AMACR at the mRNA and protein levels. Furthermore, Cell Counting Kit-8, wound healing and Transwell assays were performed to investigate the biological effects of miR200c-AMACR deregulation on prostate cancer cell proliferation, migration and invasion. It was revealed that miR200c post-transcriptionally suppressed AMACR expression by interacting with the 90–97 nucleotide sequence of the AMACR mRNA 3′-UTR. Artificial overexpression of miR200c significantly downregulated the mRNA and protein levels of AMACR in DU145 and PC-3 prostate cancer cells. Knockdown of AMACR by RNA interference, or overexpression of miR200c by recombinant adenoviral Ad-miR200c, inhibited prostate cancer cell proliferation, migration and invasiveness. Taken together, the results of the present study revealed that miR200c may suppress the AMACR expression level post-transcriptionally. The results also indicate that perturbation of the miR200c-AMACR regulatory mechanism may be involved in prostate carcinogenesis and that this may be exploited in future therapeutic approaches to prostate cancer.

MiR-203 acts as a radiosensitizer of gastric cancer cells by directly targeting ZEB1

Objective: Gastric cancer (GC) is a common tumor malignancy with high incidence and poor prognosis. Radiotherapy is one of the main strategies for GC treatment, while development of radioresistance limits the effectiveness. microRNA-203 (miR-203) has been reported to participate in progression of GC, whereas its interaction with radiosensitivity of GC and the related mechanism remain largely unclear. Methods: The expressions of miR-203 and zinc finger E-box binding homeobox 1 (ZEB1) were measured in GC tissues and cells by quantitative real-time polymerase chain reaction or western blot. Survival fraction, cell viability and apoptosis were measured in GC cells after treatment of radiation by colony formation, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay or flow cytometry, respectively. Tumor volume and weight were detected in murine xenograft model after radiation treatment. The interaction between miR-203 and ZEB1 was explored by bioinformatics analysis and luciferase activity assay. Results: miR-203 expression was down-regulated and ZEB1 mRNA level was up-regulated in GC. The expression of miR-203 was associated with radiosensitivity of GC cells. Moreover, overexpression of miR-203 decreased survival fraction, cell viability and tumor growth but promoted cell apoptosis in radiation-treated GC cells. However, knockdown of miR-203 played an opposite effect. ZEB1 was validated as a target of miR-203, and it was involved in miR-203-mediated radiosensitivity of GC cells in vitro and in vivo. Conclusion: miR-203 promoted radiosensitivity of GC cells by targeting ZEB1, indicating miR-203 as a promising radiosensitizer for GC treatment.

Ursolic acid suppresses the invasive potential of colorectal cancer cells by regulating the TGF-β1/ZEB1/miR-200c signaling pathway

Ursolic acid (UA) is a biologically active compound, commonly used in traditional Chinese medicine (TCM). It has been reported to exhibit strong anticancer properties against a variety of cancers. Our previous studies showed that UA promoted apoptosis in colorectal cancer (CRC) cells and inhibited cellular proliferation and angiogenesis. However, the effect and underlying molecular mechanism of UA in CRC progression remain unclear. In the present study, the role of UA in suppressing the migration and invasion of human colon cancer HCT116 and HCT-8 cells was investigated, using Transwell assays. In addition, to evaluate whether the anticancer properties of UA were mediated by the regulation of a double-negative feedback loop consisting of the transforming growth factor-β1 (TGF-β1)/zinc finger E-box-binding homeobox (ZEB1) pathway and microRNA (miR)-200a/b/c, reverse transcription-quantitative PCR and western blot analysis were performed. The results indicated that UA treatment significantly suppressed cellular growth, migration and invasion in HCT116 and HCT-8 cells in a dose-dependent manner. Furthermore, following UA treatment, several crucial mediators of the TGF-β1 signaling pathway, including TGF-β1, phosphorylated (p)-Smad2/3, p-focal adhesion kinase and ZEB1, were significantly downregulated in the HCT116 and HCT-8 cell lines compared with the control group. Furthermore, the ratio of N-cadherin/E-cadherin, two proteins directly downstream of the TGF-β1 signaling pathway, was found to be downregulated in UA treated CRC cells. Finally, UA significantly upregulated miR200a/b/c, with miR-200c exhibiting the highest increase in expression levels following UA treatment. Collectively, the present study suggested that inhibition of CRC cell invasion by UA occurred via regulation of the TGF-β1/ZEB1/miR-200c signaling network, which may be one of the mechanisms by which UA appears to be an effective therapeutic agent against colon cancer.

Downregulation of microRNA-200c-3p reduces damage of hippocampal neurons in epileptic rats by upregulating expression of RECK and inactivating the AKT signaling pathway

OBJECTIVE

The aim of this study is to investigate the role of mircoRNA-200c-3p (miR-200c-3p) on hippocampal neuron injury in epileptic rats through the regulation of the AKT signaling pathway by targeting RECK.

METHODS

The epilepsy rat model was induced by intraperitoneal injection of lithium chloride-pilocarpine. Successful modeled rats were injected with miR-200c-3p inhibitors, inhibitors NC, siRNA-negative control (NC) and RECK-siRNA. The astrocyte activation, levels of oxidative stress indexes, contents of inflammatory factors and the AKT signaling pathway-related proteins in hippocampus tissues were evaluated.

RESULTS

High expression of miR-200c-3p and low expression of RECK were found in the hippocampus tissues of epileptic rats. Downregulation of miR-200c-3p or upregulation of RECK decreased apoptosis of hippocampal neurons, expression of GFAP, content of MDA and increased the activities of GSH-Px and SOD, decreased expression of TNF-α, IL-1β and IL-6 as well as expression of p-PI3K/t-PI3K and p-Akt/t-Akt in hippocampus tissues of epileptic rats.

CONCLUSION

Our study provides evidence that downregulation of miR-200c-3p reduces damage of hippocampal neurons in epileptic rats by upregulating RECK and inactivating the AKT signaling pathway.

The Diagnostic and Prognostic Value of miR-200c in Gastric Cancer: A Meta-Analysis

BACKGROUND

The role of miR-200c in gastric cancer remains controversial. This study is aimed at clarifying the diagnostic and prognostic value of miR-200c in gastric cancer through a meta-analysis.

METHODS

A comprehensive literature search of PubMed, Embase, and Ovid library databases was conducted. The studies included were those conducted before December 2017. The sensitivity and specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under curve (AUC) were used to estimate the diagnostic value of miR-200c. Meanwhile, the pooled hazard ratio (HR) was used to estimate the prognostic value of miR-200c.

RESULTS

For the diagnostic value of miR-200c, six studies that included 202 patients with gastric cancer and 250 normal controls were analyzed. The sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.74, 0.66, 2.20, 0.40, 5.34, and 0.75, respectively. Subgroup analysis showed no significant difference in the type of the sample, method for testing miR-200c, and ethnicity among the patients. Meanwhile, for the prognostic value of miR-200c, seven studies comprising 935 patients with gastric cancer were analyzed. The pooled results showed that miR-200c expression was associated with overall survival (HR = 2.19) and disease-free survival (HR = 1.73), but not with progression-free survival (HR = 1.64) in patients with gastric cancer. There was no publication bias across the studies.

CONCLUSIONS

Both serum and tissue miR-200c have moderate diagnostic accuracy in gastric cancer. miR-200c could also be used as a valuable indicator for predicting the prognosis of gastric cancer patients.

Role of miR-200c in early diagnosis of gastric cancer: Current status and prospects

Gastric cancer (GC) is one of the most common malignant tumors of the digestive tract, and its morbidity and mortality still rank the second among all cancers. The proportion of patients with advanced GC is higher, and their therapeutic effect is extremely poor. In recent years, numerous studies have shown that the content of miR-200c in GC patients is significantly increased, and the level of miR-200c is closely related to epithelial-mesenchymal transition and lymph node metastasis. Therefore, in-depth disclosure of the role of miR-200c in the diagnosis of GC will not only contribute to the early diagnosis of GC, but also help develop new effective treatment strategies and judge the prognosis of patients with GC. This article reviews the role of miR-200c in the early diagnosis of GC and discusses its application prospects.

The Significance Role of microRNA-200c as a Prognostic Factor in Various Human Solid Malignant Neoplasms: A Meta-Analysis

Objective: The aim of this study was to conduct a meta-analysis of 49 relevant studies to evaluate the prognostic value of miRNA-200c in various human malignant neoplasms.

Methods: All relevant studies were identified by searching PubMed, Embase and Web of Science until August 15^st, 2018. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) of miRNA-200c for overall survival (OS) and progression-free survival (PFS)/recurrence-free survival (RFS)/disease-free survival (DFS) were calculated to investigate such associations.

Results: Overall, 49 eligible studies were included in this meta-analysis. Our results showed that high expression of miRNA-200c was significantly correlated with a poor OS in cancer (pooled HR = 1.32, 95% CI: 1.06-1.65), but was not significantly correlated with PFS/RFS/DFS in cancer (pooled HR=1.05, 95% CI: 0.84-1.23). In our subgroup analysis, high miRNA-200c expression predicted a significantly worse OS (pooled HR = 1.50, 95% CI: 1.12-2.01) only in Caucasians. Moreover, high miRNA-200c expression even showed significantly poor OS (pooled HR = 1.88, 95% CI: 1.39-2.54) in blood samples. In addition, a significantly unfavorable OS (pooled HR = 2.69, 95% CI: 1.49-4.85) and (pooled HR = 2.66, 95% CI: 1.07-6.59) associated with up-regulated miRNA-200c expression were observed in breast cancer and endometrial cancer, respectively. Besides, high miRNA-200c expression also showed significantly poor PFS/RFS/DFS (pooled HR=1.66, 95% CI: 1.03-2.67) in breast cancer.

Conclusions: Our findings indicated that high miRNA-200c expression was a promising biomarker for patient survival and disease progression in malignant tumors, especially in breast cancer and endometrial cancer. Considering the insufficient evidence, further large-scale researches and clinical studies were needed to verify these results.

Down-regulation of lncRNA-ATB inhibits epithelial-mesenchymal transition of breast cancer cells by increasing miR-141-3p expression

Long noncoding RNA activated by transforming growth factor-beta (lnc-ATB) is abnormally expressed in a number of tumor types. The aim of this study was to investigate the expression of lnc-ATB and miR-141-3p, and to determine whether lnc-ATB can regulate epithelial-mesenchymal transition (EMT) by miR-141-3p in breast cancer. Here, we found that lnc-ATB was highly expressed, whereas there was low expression of miR-141-3p in breast cancer tissues and cells. Knockdown of lnc-ATB in two breast cancer cell lines (MDA-MB-231 and BT549) significantly increased miR-141-3p expression. Down-regulation of lnc-ATB resulted in a morphological change of breast cancer cells from spindle-like to a round shape, and in a remarkable inhibition of cell migration and invasion, which were reversed by miR-141-3p inhibitor. Furthermore, we demonstrated that lnc-ATB knockdown decreased ZEB1, ZEB2, N-cadherin, and vimentin expression, and promoted E-cadherin expression, while miR-141-3p inhibitor could reverse those effects. Moreover, we proved that miR-141-3p directly bound to the 3' untranslated region (UTR) of ZEB1 and ZEB2 and negatively regulated ZEB1 and ZEB2 expression. Taken together, our results show that knockdown of lnc-ATB significantly inhibits the EMT process of breast cancer cells by increasing the expression of miR-141-3p, indicating that lnc-ATB might serve as a novel therapeutic target for breast cancer.

Carcinosarcoma of the esophagus: A report of 6 cases associated with zinc finger E-box-binding homeobox 1 expression

Esophageal carcinosarcoma (ECS) has been suggested to result from an epithelial mesenchymal transition (EMT) phenomenon. However, knowledge on its underlying molecular features is limited. The clinical and pathological features, and the prognosis of ECS require further investigation. In the present study, a total of 325 patients with esophageal tumors were observed between January 2004 and December 2014, of which 6 patients were diagnosed pathologically with ECS. The clinicopathological features were compared with those of corresponding cases with the identical pathological T stage (pT) of esophageal squamous cell carcinoma (ESCC). In terms of the clinical T stage (cT), the 6 cases were composed of cT1, cT2, cT3 and cT4 in 1, 1, 3 and 1 case, respectively. Nevertheless, pT was eventually diagnosed as pT1 in all cases. There was a large discrepancy between clinically diagnosed depth of tumor invasion prior to surgery and depth of tumor invasion following surgery. Zinc finger E-box-binding homeobox 1 (ZEB1), an EMT-associated transcription factor, was expressed only in the sarcoma component in all 6 cases of ECS. The ECS cases had a significantly poorer prognosis compared with the 115 pT1 ESCC cases. The present study suggests that the depth of invasion of ECS lesions does not correspond with their respective size, and the EMT of the carcinoma component may affect the prognosis by overexpression of the ZEB1 gene.

Sec23a mediates miR-200c augmented oligometastatic to polymetastatic progression

Background

Cancer treatment is based on tumor staging. Curative intent is only applied to localized tumors. Recent studies show that oligometastatic patients who have limited number of metastases may benefit from metastasis-directed local treatments to achieve long-term survival. However, mechanisms underlying oligometastatic to polymetastatic progression remains elusive.

Methods

The effects of miR-200c and Sec23a on tumor metastasis were verified both in vitro and in vivo. The secretome changes were detected by mass spectrometry.

Findings

We established a pair of homologous lung-metastasis derived oligometastatic and polymetastatic cell lines from human melanoma cancer cell line M14. Using the two cell lines, we have identified Sec23a, a gene target of miR-200c, suppresses miR-200c augmented oligometastatic to polymetastatic progression via its secretome. Firstly, miR-200c over-expression and Sec23a interference accelerated oligometastatic to polymetatic progression. Secondly, Sec23a functions downstream of miR-200c. Thirdly, mass spectrometric analysis of the secretory protein profile suggests that Sec23a-dependent secretome may impact metastatic colonization by modifying tumor microenvironment. Fourthly, the survival analysis using The Cancer Genome Atlas database shows Sec23a as a favorable prognostic marker for skin cutaneous melanoma, supporting the clinical relevance of our findings.

Interpretation

The finding that Sec23a is a suppressor of oligometastatic to polymetastatic progression has clinical implications. First, it provides a new theoretical framework for the development of treatments that prevent oligometastasis to polymetastasis. Second, Sec23a may be used as a favorable prognostic marker for the selection of patients with stable oligometastatic disease for oligometastasis-based local therapies of curative intent.

Fund

National Natural Science Foundations of China.

Role of exosomal small RNA in prostate cancer metastasis

Prostate cancer (PCa) is the second most common cancer in men worldwide. When the disease becomes metastatic, limited treatment strategies exist, and metastatic disease prognoses are difficult to predict. Recently, evidence has emerged, which indicates that small RNAs are detectable in patient fluids, and exosomal small RNA ectopic expression is correlated with the development, progression, and metastasis of human PCa; however, the role of small RNAs in PCa is only partially understood. In this review, we discuss the research status regarding circulating exosomal small RNAs and applications using these small RNAs in PCa particularly looking at metastatic disease. Exosomal small RNAs could be used as potential biomarkers for the early diagnosis, micrometastasis detection, and prognosis of PCa.

WIPF1 antagonizes the tumor suppressive effect of miR-141/200c and is associated with poor survival in patients with PDAC

Background

Aberrant expression of Wiskott–Aldrich syndrome protein interacting protein family member 1 (WIPF1) contributes to the invasion and metastasis of several malignancies. However, the role of WIPF1 in human pancreatic ductal adenocarcinoma (PDAC) remains poorly understood.

Methods

Human pancreatic cancer samples from PDAC patients were collected for methylation analysis. Bioinformatic prediction program and luciferase reporter assay were used to identify microRNAs regulating WIPF1 expression. The association between WIPF1 expression and the overall survival (OS) of patients with PDAC was evaluated by using The Cancer Genome Atlas (TCGA) database. The roles of miR-141/200c and WIPF1 on the invasion and metastasis of PDAC cells were investigated both in vitro and in vivo.

Results

We found that compared to the surrounding non-cancerous tissues, there was significantly increased methylation of miR-200c and miR-141 in human PDAC tissues that resulted in their silencing, whereas the members of the other cluster of miR-200 family including miR-200a, miR-200b and miR-429 were hypomethylated. Our data show that forced expression of miR-141 or miR-200c suppressed invasion and metastasis of PDAC cells both in vitro and in xenograft and identified WIPF1 as a direct target of miR-141 and miR-200c. Both miR-141 and miR-200c inhibit WIPF1 by directly interacting with its 3′-untranslated region. Remarkably, silencing of WIPF1 blocked PDAC growth and metastasis both in vitro and in vivo, whereas forced WIPF1 overexpression antagonized the tumor suppressive effect of miR-141/200c. Additionally, by using TCGA database we showed that high expression of WIPF1 correlated with poor survival in patients with PDAC. Moreover, we show that miR-141 and miR-200c blocked YAP/TAZ expression by suppressing WIPF1.

Conclusions

We have identified WIPF1 as an oncoprotein in PDAC and a direct target of miR-141/miR-200c. We have also defined the miR-141/200c-WIPF1-YAP/TAZ as a novel signaling pathway that is involved in the regulation of the invasion and metastasis of human PDAC cells.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0848-6) contains supplementary material, which is available to authorized users.

CRISPR-Mediated Reactivation of DKK3 Expression Attenuates TGF-β Signaling in Prostate Cancer

The DKK3 gene encodes a secreted protein, Dkk-3, that inhibits prostate tumor growth and metastasis. DKK3 is downregulated by promoter methylation in many types of cancer, including prostate cancer. Gene silencing studies have shown that Dkk-3 maintains normal prostate epithelial cell homeostasis by limiting TGF-β/Smad signaling. While ectopic expression of Dkk-3 leads to prostate cancer cell apoptosis, it is unclear if Dkk-3 has a physiological role in cancer cells. Here, we show that treatment of PC3 prostate cancer cells with the DNA methyltransferase (DNMT) inhibitor decitabine demethylates the DKK3 promoter, induces DKK3 expression, and inhibits TGF-β/Smad-dependent transcriptional activity. Direct induction of DKK3 expression using CRISPR-dCas9-VPR also inhibited TGF-β/Smad-dependent transcription and attenuated PC3 cell migration and proliferation. These effects were not observed in C4-2B cells, which do not respond to TGF-β. TGF-β signals can regulate gene expression directly via SMAD proteins and indirectly by increasing DNMT expression, leading to promoter methylation. Analysis of genes downregulated by promoter methylation and predicted to be regulated by TGF-β found that DKK3 induction increased expression of PTGS2, which encodes cyclooxygenase-2. Together, these observations provide support for using CRISPR-mediated induction of DKK3 as a potential therapeutic approach for prostate cancer and highlight complexities in Dkk-3 regulation of TGF-β signaling.

Genome-wide Analyses on Single Disease Samples for Potential Biomarkers and Biological Features of Molecular Subtypes: A Case Study in Gastric Cancer

Purpose: Based on the previous 3 well-defined subtypes of gastric adenocarcinoma (invasive, proliferative and metabolic), we aimed to find potential biomarkers and biological features of each subtype.

Methods: The genome-wide co-expression network of each subtype of gastric cancer was firstly constructed. Then, the functional modules in each genome-wide co-expression network were divided. Next, the key genes were screened from each functional module. Finally, the enrichment analysis was performed on the key genes to mine the biological features of each subtype. Comparative analysis between each pair of subtypes was performed to find the common and unique features among different subtypes.

Results: A total of 207 key genes were identified in invasive, 215 key genes in proliferative, and 204 key genes in metabolic subtypes. Most key genes in each subtype were unique and new findings compared with that of the existing related researches. The GO and KEGG enrichment analyses for the key genes of each subtype revealed important biological features of each subtype.

Conclusions: For a subtype, most identified key genes and important biological features were unique, which means that the key genes can be used as the potential biomarker of a subtype, and each subtype of gastric cancer might have different occurrence and development mechanisms. Thus, different diagnosis and therapy methods should be applied to the invasive, proliferative and metabolic subtypes of gastric cancer.

Anti-invasive effect of Cyclamen pseudibericum extract on A549 non-small cell lung carcinoma cells via inhibition of ZEB1 mediated by miR-200c

Scientists are increasingly focusing attention on natural products of plant origin for use as agents in cancer protection and treatment. Cyclamen L. tuber extracts contain saponin glycosides that have been shown to have anti-cancer and other biological activities. The epithelial-to-mesenchymal transition (EMT) is thought to enhance malignant tumour progress. The transcriptional repressor zinc-finger E-box binding homeobox 1 (ZEB1) is an important inducer of EMT in different human tumours and has recently been shown to boost invasion by tumour cells. In this study, we investigated the effects of endemic Cyclamen pseudibericum (CP) saponin-rich tuber extract on the capacity of non-small cell lung cancer line A549 cells to proliferate, invade and migrate and also examined the expression levels of several invasion-migration-related microRNAs (miRNAs) to identify those which directly targeted ZEB1. The cytotoxicity effect of the CP extract on the A549 cancer cells was determined by the luminometric method. The half-minimal (50%) inhibitory concentration dose in the A549 cells was determined to be 41.64 ± 2.35 µg/mL. Using the Matrigel invasion chamber system and the wound healing assay we observed that the CP extract suppressed the invasion and migration capacity of A549 cells, respectively. The expression of miRNAs in A549 cells was evaluated by real-time PCR. Our data showed that overexpression of miRNA miR-200c hindered the EMT by increasing the expression of E-cadherin and decreasing the expression of both N-cadherin and vimentin through the direct targeting of ZEB1. These findings suggest that the saponin-rich tuber extract of CP may have considerable anti-cancer properties in lung cancer. Further studies are required to examine in detail the molecular-based mechanism involved in the EMT process of the extract along with isolation and identification of active saponin components.

GSE1 predicts poor survival outcome in gastric cancer patients by SLC7A5 enhancement of tumor growth and metastasis

Gastric cancer remains a malignancy with poor survival outcome. We herein report that GSE1, a proline-rich protein, possesses a role in the progression of human gastric cancer. The expression of GSE1 was observed to be much higher in human gastric cancer tissues compared with normal gastric tissues, and GSE1 expression correlated positively with lymph node metastasis, histological grade, depth of invasion, and clinical stage in gastric cancer patients. Moreover, GSE1 expression was also associated with decreased post-operative relapse-free survival and overall survival in the cohort. The forced expression of GSE1 in gastric cancer cell lines resulted in increased cell proliferation, increased colony formation, enhanced cell migration, and invasion. Furthermore, forced expression of GSE1 also increased tumor size and enhanced lung metastasis in xenograft models. The depletion of endogenous GSE1 with shRNAs decreased the oncogenicity and invasiveness of gastric cancer cells both in vitro and in vivo In addition, GSE1 was determined to be a direct target of miR-200b and miR-200c. Furthermore, GSE1 positively regulated the downstream gene SLC7A5 (also known as LAT-1), which was scanned and verified from mRNA sequencing. GSE1 therefore possesses an oncogenic role in human gastric cancer, and targeted therapeutic approaches to inhibit GSE1 function in gastric cancer warrant further consideration.

miR-200c regulates the proliferation, apoptosis and invasion of gastric carcinoma cells through the downregulation of EDNRA expression

This study aimed to investigate the regulatory effects of microRNA (miR)‑200c on the proliferation, apoptosis and invasion of gastric carcinoma cells and to elucidate the underlying mechanisms involving the possible role of endothelin receptor A (EDNRA). The expression levels of miR‑200c and EDNRA in the gastric carcinoma cell lines, BGC‑823, SGC‑7901 and HGC‑27, and in GES‑1 normal gastric cells were evaluated by RT‑PCR and western blot analysis. The gastric carcinoma cells, particularly the BGC‑823 cells, expressed significantly lower levels of miR‑200c than the normal gastric cells (P<0.01). Thus, the BGC‑823 cells were employed as model cells. In comparison to the normal gastric cells, EDNRA was overexpressed in the gastric carcinoma cells (P<0.01). Following the transfection of the gastric carcinoma cells with miR‑200c mimics, or negative control vector (miR‑200c NC), or with siRNA targeting EDNRA (siRNA EDNRA) or negatvie control siRNA (siRNA NC), the expression levels were assessed again by RT‑PCR and western blot analysis. The successful transfection of miR‑200c mimics was observed and this markedly elevated the expression of miR‑200c (P<0.01). The transfection of miR‑200c mimics or siRNA EDNRA notably decreased the EDNRA mRNA and protein expression levels (both P<0.01). In additoin, dual‑luciferase reporter gene analysis was performed to reveal the targeting relationship between miR‑200c and EDNRA. EDNRA was found to be the downstream target gene of miR‑200c. Moreover, methyl thiazolyl tetrazolium (MTT) assay, Hoechst staining and Transwell assay were conducted to demonstrate the effects of miR‑200c mimics or siRNA EDNRA on the proliferation, apoptosis and invasion of the gastric carcinoma cells, respectively. We found that transfection with miR‑200c mimics and siRNA EDNRA were able to markedly suppress the proliferation and invasive capacity, and to promote the apoptosis of the gastric carcinoma cells (all P<0.01). On the whole, our data indicate that miR‑200c regulates the proliferation, apoptosis and invasion of gastric carcinoma cells through the downregulation of EDNRA expression.

Expression level of microRNA-200c is associated with cell morphology in vitro and histological differentiation through regulation of ZEB1/2 and E-cadherin in gastric carcinoma

Scirrhous type gastric cancer is characterized by diffuse infiltration of poorly differentiated adenocarcinoma cells and poor prognosis. Although association of poorly differentiated histology with reduction in E-cadherin expression, as well as association of microRNA (miR)-200c with E-cadherin through regulation of ZEB1/2, has been reported, participation of miR-200c in gastric carcinogenesis is not fully understood. We used 6 cell lines originating from gastric cancers, and investigated levels of miR-200c along with its target mRNAs ZEB1/2 and E-cadherin by qRT-PCR. ZEB1 and E-cadherin protein expression was also assessed via western blotting. Furthermore, we investigated the expression levels of miR-200c by in situ hybridization, along with the expression of ZEB1 and E-cadherin by immunohistochemistry, in 97 gastric adenocarcinoma tissues. Inverse correlation between miR-200c and ZEB1 levels were obtained by qRT-PCR in cell lines (P<0.05). Cell lines with low miR-200c and high ZEB1 exhibited low E-cadherin expression in both qRT-PCR and western blotting, and exhibited spindle-shaped morphology, in contrast to round cell morphology in those cell lines with high miR-200c levels. Inverse correlations were also obtained between miR-200c and ZEB1 as well as between ZEB1 and E-cadherin levels in tissue samples (P<0.001). Cancer tissues with low miR-200c, high ZEB1, and low E-cadherin expression were associated with poorly differentiated histology, in contrast to tubular form in cancers with high miR-200c expression levels (P<0.001). Our data revealed that downregulation of miR-200c primarily regulated cell morphology by downregulation of E-cadherin through upregulation of ZEB1, leading to poorly differentiated histology in gastric cancer.

Dynamic and Modularized MicroRNA Regulation and Its Implication in Human Cancers

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

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

BACKGROUND

Previous articles have reported that expression levels of microRNAs (miRNAs) are associated with survival time of patients with gastric cancer (GC). A systematic review and meta-analysis was performed to study the outcome of it.

DESIGN

Meta-analysis.

METHODS

English studies estimating expression levels of miRNAs with any of survival curves in GC were identified up till March 19, 2017 through performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two authors independently. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

RESULTS

Sixty-nine relevant articles about 26 miRNAs with 6148 patients were ultimately included. GC patients with high expression of miR-20b (HR=2.38, 95%CI=1.16-4.87), 21 (HR=1.77, 95%CI=1.01-3.08), 106b (HR=1.84, 95%CI=1.15-2.94), 196a (HR=2.66, 95%CI=1.94-3.63), 196b (HR=1.67, 95%CI=1.38-2.02), 214 (HR=1.84, 95%CI=1.27-2.67) or low expression of miR-125a (HR=2.06, 95%CI=1.26-3.37), 137 (HR=3.21, 95%CI=1.68-6.13), 141 (HR=2.47, 95%CI=1.34-4.56), 145 (HR=1.62, 95%CI=1.07-2.46), 146a (HR=2.60, 95%CI=1.63-4.13), 206 (HR=2.85, 95%CI=1.73-4.70), 218 (HR=2.61, 95%CI=1.74-3.92), 451 (HR=1.73, 95%CI=1.19-2.52), 486-5p (HR=2.45, 95%CI=1.65-3.65), 506 (HR=2.07, 95%CI=1.33-3.23) have significantly poor OS (P<0.05).

CONCLUSIONS

In summary, miR-20b, 21, 106b, 125a, 137, 141, 145, 146a, 196a, 196b, 206, 214, 218, 451, 486-5p and 506 demonstrate significantly prognostic value. Among them, miR-20b, 125a, 137, 141, 146a, 196a, 206, 218, 486-5p and 506 are strong biomarkers of prognosis in GC.

MicroRNA-200c inhibits epithelial-mesenchymal transition, invasion, and migration of lung cancer by targeting HMGB1

MicroRNAs (miRs) play critical roles in cancer development, proliferation, epithelial-mesenchymal transition (EMT), invasion, and migration through regulating the expression of oncogenes and tumour suppressor genes. Previous studies have indicated that miR-200c acts as a tumour suppressor in various cancers by downregulating high-mobility group box 1 (HMGB1) and thereby suppressing EMT and metastasis. In addition, miR-200c was reported to be downregulated and correlated with poor outcomes in non-small cell lung cancer (NSCLC). However, its functional role in HMGB1 regulation in NSCLC is still unclear. This study aimed to clarify whether miR-200c acts as a tumour suppressor in NSCLC by downregulating HMGB1, which is associated with EMT, invasion, cytoskeleton rearrangement, and migration in vitro and in vivo. In order to demonstrate HMGB1 downregulation by miR-200c, the NSCLC cell line A549 was transfected with miR-200c mimic or inhibitor. The mimic significantly reduced HMGB1 expression and suppressed EMT, invasion, and migration, while the inhibitor generated the opposite effects. Additionally, using xenograft mouse models, we confirmed that HMGB1 overexpression increased tumour EMT. In summary, our results demonstrated that miR-200c could suppress EMT, invasion, and migration of NSCLC cells by downregulating HMGB1.

Prognostic role of microRNAs in human gastrointestinal cancer: A systematic review and meta-analysis

BACKGROUND

Gastrointestinal cancers (GICs) mainly including esophageal, gastric and colorectal cancer, are the most common cause of cancer-related death and lead into high mortality worldwide. We performed this systematic review and meta-analysis to elucidate relationship between multiple microRNAs (miRs) expression and survival of GIC patients.

METHODS

We searched a wide range of database. Fixed-effects and random-effects models were used to calculate the pooled hazard ratio values of overall survival and disease free survival. In addition, funnel plots were used to qualitatively analyze the publication bias and verified by Begg's test while it seems asymmetry.

RESULTS

60 studies involving a total of 6225 patients (1271 with esophageal cancer, 3467 with gastric cancer and 1517 with colorectal cancer) were included in our meta-analysis. The pooled hazard ratio values of overall survival related to different miRs expression in esophageal, gastric, colorectal and gastrointestinal cancer were 2.10 (1.78-2.49), 2.02 (1.83-2.23), 2.54 (2.14-3.02) and 2.15 (1.99-2.31), respectively. We have identified a total of 59 miRs including 23 significantly up-regulated expression miRs (miR-214, miR-17, miR-20a, miR-200c, miR-107, miR-27a, etc.) and 36 significantly down-regulated expression miRs (miR-433, let-7g, miR-125a-5p, miR-760, miR-206, miR-26a, miR-200b, miR-185, etc.) correlated with poor prognosis in GIC patients. Moreover, 35 of them revealed mechanisms.

CONCLUSION

Overall, specific miRs are significantly associated with the prognosis of GIC patients and potentially eligible for the prediction of patients survival. It also provides a potential value for clinical decision-making development and may serve as a promising miR-based target therapy waiting for further elucidation.

A novel fine tuning scheme of miR-200c in modulating lung cell redox homeostasis

Oxidative stress induces miR-200c, the predominant microRNA (miRNA) in lung tissues; however, the antioxidant role and biochemistry of such induction have not been clearly defined. Therefore, a lung adenocarcinoma cell line (A549) and a normal lung fibroblast (MRC-5) were used as models to determine the effects of miR-200c expression on lung antioxidant response. Hydrogen peroxide (H₂O₂) upregulated miR-200c, whose overexpression exacerbated the decrease in cell proliferation, retarded the progression of cells in the G2/M-phase, and increased oxidative stress upon H₂O₂ stimulation. The expression of three antioxidant proteins, superoxide dismutase (SOD)-2, haem oxygenase (HO)-1, and sirtuin (SIRT) 1, was reduced upon H₂O₂ stimulation in miR-200c-overexpressed A549 cells. This phenomenon of increased oxidative stress and antioxidant protein downregulation also occurs simultaneously in miR-200c overexpressed MRC-5 cells. Molecular analysis revealed that miR-200c inhibited the gene expression of HO-1 by directly targeting its 3'-untranslated region. The downregulation of SOD2 and SIRT1 by miR-200c was mediated through zinc finger E-box-binding homeobox 2 (ZEB2) and extracellular signal-regulated kinase 5 (ERK5) pathways, respectively, where knockdown of ZEB2 or ERK5 decreased the expression of SOD2 or SIRT1 in A549 cells. LNA anti-miR-200c transfection in A549 cells inhibited the endogenous miR-200c expression, resulting in increased expressions of antioxidant proteins, reduced oxidative stress and recovered cell proliferation upon H₂O₂ stimulation. These findings indicate that miR-200c fine-tuned the antioxidant response of the lung cells to oxidative stress through several pathways, and thus this study provides novel information concerning the role of miR-200c in modulating redox homeostasis of lung.

MiR-200c inhibits bladder cancer progression by targeting lactate dehydrogenase A

Lactate dehydrogenase A (LDHA) is overexpressed in various cancers. We investigated LDHA expression and function in bladder cancer. We demonstrate that LDHA is up-regulated in bladder cancer cells and promotes proliferation, invasion, and glycolysis. Additionally, we found that microRNA (miR)-200c directly targets LDHA in bladder cancer cells. Ectopic expression of miR-200c inhibited LDHA-induced glycolysis, cell proliferation, and invasion. Thus, targeting LDHA through miR-200c is a potential therapeutic strategy in bladder cancer.

Members of the microRNA-200 family are promising therapeutic targets in cancer

MicroRNAs (miRs) are non-coding, single-stranded RNA molecules that regulate gene expression at the posttranscriptional level. Abnormal expression of miR may result in pathophysiological processes occurring that stimulate the development of various diseases. miRs are commonly dysregulated in cancer and may act as either oncogenes or tumor suppressors. Studies have indicated that members of the miR-200 family are involved in different aspects of cancer biology, including the epithelial-to-mesenchymal transition, tumor angiogenesis and chemoresistance by targeting and repressing the expression of several key messenger RNAs. The present review aims to summarize the role of the miR-200 family and its potential mechanism of action in tumor progression, which may advance the development of novel therapeutic drugs against tumor metastasis in clinical cancer treatment.

Decitabine reverses TGF-β1-induced epithelial-mesenchymal transition in non-small-cell lung cancer by regulating miR-200/ZEB axis

OBJECTIVE

Epithelial-mesenchymal transition (EMT) is a crucial driver of tumor progression. Tumor growth factor-beta 1 (TGF-β1) is an important factor in EMT induction in tumorigenesis. The targeting of EMT may, therefore, represent a promising approach in anticancer treatment.

METHODS

In this study, we determined the effect of decitabine, a DNA methyltransferase inhibitor, on TGF-β1-induced EMT in non-small-cell lung cancer (NSCLC) PC9 and A549 cells. We also assessed the involvement of the miR-200/ZEB axis.

RESULTS

Decitabine reversed TGF-β1-induced EMT in PC9 cells, but not in A549 cells. This phenomenon was associated with epigenetic changes in the miR-200 family, which regulated EMT by altering the expression of ZEB1 and ZEB2. TGF-β1 induced aberrant methylation in miR-200 promoters, leading to EMT in PC9 cells. Decitabine attenuated this effect and inhibited tumor cell migration in vitro and in vivo. In A549 cells, however, neither TGF-β1 nor decitabine exhibited an effect on miR-200 promoter methylation.

CONCLUSION

Our findings suggest that epigenetic regulation of the miR-200/ZEB axis is responsible for EMT induction by TGF-β1 in PC9 cells. Decitabine inhibits EMT in NSCLC cell PC9 through its epigenetic-based therapeutic activity.