miR-145 inhibits invasion and metastasis by directly targeting Smad3 in nasopharyngeal cancer

Pancreatic cancer and exosomes: role in progression, diagnosis, monitoring, and treatment

Pancreatic cancer (PC) is one of the most dangerous diseases that threaten human life, and investigating the details affecting its progression or regression is particularly important. Exosomes are one of the derivatives produced from different cells, including tumor cells and other cells such as Tregs, M2 macrophages, and MDSCs, and can help tumor growth. These exosomes perform their actions by affecting the cells in the tumor microenvironment, such as pancreatic stellate cells (PSCs) that produce extracellular matrix (ECM) components and immune cells that are responsible for killing tumor cells. It has also been shown that pancreatic cancer cell (PCC)-derived exosomes at different stages carry molecules. Checking the presence of these molecules in the blood and other body fluids can help us in the early stage diagnosis and monitoring of PC. However, immune system cell-derived exosomes (IEXs) and mesenchymal stem cell (MSC)-derived exosomes can contribute to PC treatment. Immune cells produce exosomes as part of the mechanisms involved in the immune surveillance and tumor cell-killing phenomenon. Exosomes can be modified in such a way that their antitumor properties are enhanced. One of these methods is drug loading in exosomes, which can significantly increase the effectiveness of chemotherapy drugs. In general, exosomes form a complex intercellular communication network that plays a role in developing, progressing, diagnosing, monitoring, and treating pancreatic cancer.

MicroRNA-145-5p modulates Krüppel-like factor 5 and inhibits cell proliferation, migration, and invasion in nasopharyngeal carcinoma

Background

In several human cancers, Krüppel-like factor 5 (KLF5), a zinc finger transcription factor, can contribute to both tumor progression or suppression; however, the precise role of KLF5 in nasopharyngeal carcinoma (NPC) remains poorly understood. In this study, the association between KLF5 and microRNA-145-5p (miR-145-5p) in NPC cells was elucidated.

Results

Our results showed that KLF5 expression was up-regulated in NPC group compared to normal group. We found that KLF5 exhibited an oncogenic role in NPC cells. The upregulation of miR-145-5p inhibited the proliferation, migration, and invasion of NPC cells. It was observed that miR-145-5p could down-regulate the mRNA and protein expression of KLF5 in NPC cell lines. Additionally, the activity of focal adhesion kinase (FAK), a migration marker, was regulated by miR-145-5p and KLF5 in NPC cells.

Conclusions

The results of this study indicated that miR-145-5p could repress the proliferation, migration, and invasion of NPC cells via KLF5/FAK regulation, and could be a potential therapeutic target for patients with NPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-022-00430-9.

Long Noncoding RNA LINC02470 Sponges MicroRNA-143-3p and Enhances SMAD3-Mediated Epithelial-to-Mesenchymal Transition to Promote the Aggressive Properties of Bladder Cancer

Simple Summary

Long noncoding RNAs (lncRNAs) were proposed as novel tumor prognostic markers, including for predicting bladder cancer progression, and the competing endogenous RNA (ceRNA) hypothesis conceived an accessible entry point to discover potential lncRNA candidates. This study indicated that LINC02470 promotes bladder cancer cell viability, migration, invasion, and in vivo tumorigenicity by sponging miR-143-3p and consequently rescuing SMAD3 translation to activate the TGF-β-induced EMT process. These data demonstrate that the LINC02470–miR-143-3p–SMAD3 ceRNA axis directly regulates the major transcription factor of TGF-β signaling, SMAD3, thereby inducing the EMT process in bladder cancer and enhancing the aggressiveness of bladder cancer cells.

Abstract

Bladder cancer progression and metastasis have become major threats in clinical practice, increasing mortality and therapeutic refractoriness; recently, epigenetic dysregulation of epithelial-to-mesenchymal transition (EMT)-related signaling pathways has been explored. However, research in the fields of long noncoding RNA (lncRNA) and competing endogenous RNA (ceRNA) regulation in bladder cancer progression is just beginning. This study was designed to determine potential EMT-related ceRNA regulation in bladder cancer progression and elucidate the underlying mechanisms that provoke aggressiveness. After screening the intersection of bioinformatic pipelines, LINC02470 was identified as the most upregulated lncRNA during bladder cancer initiation and progression. Both in vitro and in vivo biological effects indicated that LINC02470 promotes bladder cancer cell viability, migration, invasion, and tumorigenicity. On a molecular level, miR-143-3p directly targets and reduces both LINC02470 and SMAD3 RNA expression. Therefore, the LINC02470–miR-143-3p–SMAD3 ceRNA axis rescues SMAD3 translation upon LINC02470 sponging miR-143-3p, and SMAD3 consequently activates the TGF-β-induced EMT process. In conclusion, this is the first study to demonstrate that LINC02470 plays a pivotally regulatory role in the promotion of TGF-β-induced EMT through the miR-143-3p/SMAD3 axis, thereby aggravating bladder cancer progression. Our study warrants further investigation of LINC02470 as an indicatively prognostic marker of bladder cancer.

Long ncRNA MALAT1 promotes cell proliferation, migration, and invasion in prostate cancer via sponging miR-145

Background

The long non-coding (lncRNA) RNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) is known to promote tumorigenesis, whereas microRNA-145 (miR-145) plays an antitumor role in several cancers. In this study, we aimed to elucidate the role of MALAT1 and miR-145 in prostate cancer cells and investigate the effect of MALAT1 downregulation on prostate cancer (PCa) cells in vitro in vivo.

Methods

The Cancer Genome Atlas (TCGA) datasets were used to carry out the initial bioinformatics analysis; the findings were then tested in LNCaP and CWR22Rv1 cell lines. Western blot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to evaluate the levels of MALAT1 and miR-145 along with related biomarkers. Furthermore, wound-healing and Transwell assays were performed to test the migratory and invasive abilities of PCa cells. Luciferase reporter assays were used to validate the relationship between MALAT1 and miR-145; their down-stream target genes were also studied. To further substantiate these findings in an animal model, tumor studies including immunofluorescence staining of tissues were carried in nude mice.

Results

The expression of MALAT1 was upregulated in both LNCaP cell lines and CWR22Rv1 cell lines (F=2.882, t=13.370, P<0.001; F=2.268, t=15.859, P<0.001). Knockdown of MALAT1 reduced the migratory and invasive capabilities of PCa cells (F=0.017, t=12.212, P<0.001; F=10.723, t=6.016, P=0.002). Using direct binding, MALAT1 suppressed the antitumor function of miR-145, which in turn upregulated transforming growth factor-β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) via SMAD3 and TGFBR2 (F=2.097, t=5.389, P=0.006; F=1.306, t=4.155, P=0.014).

Conclusions

We confirmed that MALAT1 acts as a competing endogenous RNA (ceRNA) of miR-145. The MALAT1 based regulation of MiR-145-5p-SMAD3/TGFBR2 interactions could be an intriguing molecular pathway for the progression of PCa.

MicroRNA-145 targets in cancer and the cardiovascular system: evidence for common signaling pathways

miRNAs are small regulatory RNAs which govern gene expression post-transcriptionally by primarily binding to the 3'-UTR of mRNA target genes. miR-145 is a well-studied miRNA that has been implicated in controlling a range of biological processes. miR-145 is expressed in a variety of tissues and cell types and acts as a tumor-suppressor by regulating target gene signaling pathways involved in different aspects of tumor growth and progression. There is also strong evidence that highlights the important functions of miR-145 in the cardiovascular system. Here, we review the mechanisms of miR-145 in tumorigenesis and cancer progression and compare and contrast with the roles of miR-145 in cardiovascular development and disease. We discuss the important targets of miR-145 in cancer and their possible link to the cardiovascular system.

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

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

Silencing of Long Non-coding RNA SMAD5-AS1 Reverses Epithelial Mesenchymal Transition in Nasopharyngeal Carcinoma via microRNA-195-Dependent Inhibition of SMAD5

Long non-coding RNAs (lncRNAs) have gained widespread attention in recent years as a key regulator of diverse biological processes, but the knowledge of the mechanisms by which they act is still very limited. Differentially expressed lncRNA SMAD5 antisense RNA 1 (SMAD5-AS1) in nasopharyngeal carcinoma (NPC) and normal samples shown by in silico analyses were selected as the main subject, and then microRNA-195 (miR-195) was suggested to bind to SMAD5-AS1 and SMAD5. Therefore, the purpose of the present study was to investigate the effects of SMAD5-AS1/miR-195/SMAD5 on epithelial-mesenchymal transition (EMT) in NPC cells. High expression of SMAD5-AS1 and SMAD5 but low miR-195 expression was determined in NPC tissues and NPC cell lines by RT-qPCR and western blot analysis. SMAD5-AS1 could upregulate SMAD5 expression by competitively binding to miR-195 in NPC cells. Loss- and gain-of-function investigations were subsequently conducted in NPC cells (CNE-2 and CNE-1) to explore the role of SMAD5-AS, miR-195 and SMAD5 in NPC progression by assessing cellular biological functions and tumorigenic ability in vivo as well as determining the expression of EMT markers. Downregulation of SMAD5-AS1 or SMAD5 or overexpression of miR-195 led to inhibited NPC cell proliferation, invasion and migration and reversed EMT, enhanced apoptosis in vitro as well as restrained tumor growth in vivo. In conclusion, our findings indicate that silencing of lncRNA SMAD5-AS1 induces the downregulation of SMAD5 by miR-195, eventually repressing EMT in NPC. Hence, SMAD5-AS1 may represent a potential therapeutic target for NPC intervention.

Mechanism of epithelial‑mesenchymal transition inhibited by miR‑203 in non‑small cell lung cancer

The aim of the present study was to investigate whether miR-203 can inhibit transforming growth factor-β (TGF-β)-induced epithelial-mesenchymal transition (EMT), and the migration and invasion ability of non-small cell lung cancer (NSCLC) cells by targeting SMAD3. In the present study, the expression levels of miR-203, SMAD3 mRNA and protein in NSCLC tissues were examined, as well as their corresponding paracancerous samples. The miR-203 mimics and miR-203 inhibitor were transfected into the H226 cell line. RT-qPCR was used to assess the expression levels of E-cadherin, Snail, N-cadherin and vimentin mRNA, and western blotting was performed to detect the expression levels of p-SMAD2, SMAD2, p-SMAD3, SMAD3 and SMAD4. The cell migration and invasion abilities were detected by Transwell assays. The target site of SMAD3 was predicted by the combined action between miR-203 and dual luciferase. The results revealed that the RNA levels of miR-203, compared with paracancerous tissues, were decreased in NSCLC tissues, while SMAD3 mRNA and protein levels were upregulated, and miR-203 inhibited SMAD3 expression. Induction of TGF-β led to decreased E-cadherin mRNA levels, upregulation of Snail, N-cadherin and vimentin mRNA levels (P<0.05), and significant increase in cell migration and invasion, whereas transfection of miR-203 mimics reversed the aforementioned results (P<0.05). Conversely, miR-203 inhibitor could further aggravate the aforementioned results (P<0.05). Western blot results revealed that transfection of miR-203 mimics significantly reduced the protein expression of SMAD3 and p-SMAD3 (P<0.05). Furthermore, the results of the Dual-Luciferase assay revealed that miR-203 inhibited SMAD3 expression by interacting with specific regions of its 3′-UTR. Overall, a novel mechanism is revealed, in which, miR-203 can inhibit SMAD3 by interacting with specific regions of the 3′-UTR of SMAD3, thereby restraining TGF-β-induced EMT progression and migration and invasion of NSCLC cells.

Long noncoding RNA SMAD5-AS1 acts as a microRNA-106a-5p sponge to promote epithelial mesenchymal transition in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial cancer of the head and neck with high prevalence in southern China, which is accompanied by notable invasiveness and metastasis. Long noncoding RNAs (lncRNAs) participate in the progression of various cancers including NPC. Microarray-based analysis identified highly expressed lncRNA mothers against decapentaplegic homolog 5 (SMAD5)-antisense RNA 1 (AS1) related to NPC. Interestingly, it is found that SMAD5-AS1 competitively bound to microRNA (miR)-106a-5p to regulate SMAD5. Herein, the study aimed to clarify the role of SMAD5-AS1/miR-106a-5p/SMAD5 axis in the process of epithelial mesenchymal transition (EMT) in NPC. SMAD5-AS1 was highly expressed and miR-106a-5p was poorly expressed in NPC tissues and cell lines. The NPC cells were treated with a series of small interfering RNAs, mimics, or inhibitors to explore the effects of SMAD5-AS1, SMAD5, and miR-106a-5p on EMT, cell proliferation, migration, and invasion in NPC. Of note, SMAD5-AS1 silencing or miR-106a-5p overexpression reduced expression of N-cadherin, matrix metallopeptidase 9, Snail, and Vimentin while elevating E-cadherin expression, thus inhibiting EMT, cell proliferation, migration, and invasion in NPC by down-regulation of SMAD5. Moreover, SMAD5 silencing could reduce the ability of EMT induced by SMAD5-AS1 up-regulation. SMAD5-AS1 silencing or miR-106a-5p elevation inhibited tumorigenesis in nude mice. Taken together, SMAD5-AS1 silencing suppressed EMT, cell proliferation, migration, and invasion in NPC by elevating miR-106a-5p to down-regulate SMAD5, which provided a novel therapeutic target for NPC treatment.-Zheng, Y.-J., Zhao, J.-Y., Liang, T.-S., Wang, P., Wang, J., Yang, D.-K., Liu, Z.-S. Long noncoding RNA SMAD5-AS1 acts as a microRNA-106a-5p sponge to promote epithelial mesenchymal transition in nasopharyngeal carcinoma.

Compound Astragalus and Salvia miltiorrhiza extract inhibits hepatocellular carcinoma progression via miR-145/miR-21 mediated Smad3 phosphorylation

ETHNOPHARMACOLOGICAL RELEVANCE

Compound Astragalus and Salvia miltiorrhiza extract (CASE), containing astragalosides, astragalus polysaccharide extracted from Astragalus membranaceus (Fisch.) Bge. and salvianolic acids from Salvia miltiorhiza Bge., has been found to inhibit hepatocarcinogenesis via mediating transforming growth factor-β (TGF-β)/Smad signaling, especially Smad3 phosphorylation. The crucial interaction between microRNA-145/microRNA-21 (miR-145/miR-21) and Smad3 phosphorylation is implicated in the pathogenesis and progression of hepatocellular carcinoma (HCC). However, effects of CASE on HCC progression involved in the expression of miR-145/miR-21 and their interaction with Smad3 phosphorylation downstream of TGF-β/MAPK/Smad pathway remain unclear. This study addressed above questions using in vitro (HepG2 cells) and in vivo (Xenografts of nude mice) models of HCC.

MATERIALS AND METHODS

In vivo [Diethylnitrosamine (DEN)-induced HCC in rats] and in vitro [TGF-β₁-stimulated HepG2 cells] models of HCC were established and co-administrated using graded doses/concentrations CASE (60, 120, 240 mg/kg used in rats; 20, 40, 80 µg/ml used in HepG2 cells), miR-145 and miR-21 were measured. HepG2 cells were transfected with miR-145 antagomir, miR-21 agomir and Smad3C/L plasmids (Smad3 EPSM, Smad3 3S-A and Smad3 WT related to up-regulated expression of pSmad3C, pSmad3L and pSmad3C/3L respectively) and then treated by CASE (80 µg/ml). Similarly, HepG2 cell xenografted nude mice were administered with miR-145 antagomir, miR-21 agomir and CASE (310 mg/kg); Smad3 WT, Smad3 EPSM and Smad3 3S-A plasmids stably transfected HepG2 cell lines were constructed respectively and their xenografted nude mice were established, and then treated by CASE (310 mg/kg). Cell proliferation, migration, apoptosis, tumor growth and histopathologic characteristics of xenografts were assessed; also, domain-specific Smad3 phosphorylation isoforms (pSmad3C/pSmad3L), activated MAPKs (pERK1/2, pJNK1/2, pp38) and miR-145, miR-21 were measured.

RESULTS

CASE up-regulated miR-145 while down-regulated miR-21 expression in both rats with DEN-induced HCC and TGF-β₁-stimulated HepG2 cells; CASE inhibited cell migration, proliferation and tumor growth while facilitated cell apoptosis in TGF-β₁-stimulated HepG2 cells and xenografts of nude mice with miR-145 antagomir/miR-21 agomir treatment via increasing miR-145 and facilitating miR-145 modulated pSmad3L→pSmad3C signaling switch while decreasing miR-21 and inhibiting miR-21 modulated MAPK-dependent Smad3L phosphorylation. Also, up-regulated pSmad3C enhanced inhibited effect of CASE on tumor growth and facilitated effect of CASE on cell apoptosis involved in increased miR-145 while decreased miR-21 expression, however, inverse phenomena were observed when up-regulated pSmad3L.

CONCLUSION

Our results suggest that CASE inhibits HCC progression via mediating the interaction of miR-145/miR-21 and Smad3 phosphorylation, especially miR-145/miR-21 mediated Smad3 phosphorylation, which maybe provides an important theoretical foundation for CASE's anti-HCC therapy used for patients in a near future.

Regulatory mechanisms of miR-145 expression and the importance of its function in cancer metastasis

MicroRNAs are post-transcriptional mediators of gene expression and regulation, which play influential roles in tumorigenesis and cancer metastasis. The expression of tumor suppressor miR-145 is reduced in various cancer cell lines, containing both solid tumors and blood malignancies. However, the responsible mechanisms of its down-regulation are a complicated network. miR-145 is potentially able to inhbit tumor cell metastasis by targeting of multiple oncogenes, including MUC1, FSCN1, Vimentin, Cadherin, Fibronectin, Metadherin, GOLM1, ARF6, SMAD3, MMP11, Snail1, ZEB1/2, HIF-1α and Rock-1. This distinctive role of miR-145 in the regulation of metastasis-related gene expression may introduce miR-145 as an ideal candidate for controlling of cancer metastasis by miRNA replacement therapy. The present review aims to discuss the current understanding of the different aspects of molecular mechanisms of miR-145 regulation as well as its role in r metastasis regulation.

Dicer deficiency in proximal tubules exacerbates renal injury and tubulointerstitial fibrosis and upregulates Smad2/3

Renal fibrosis is a common pathological feature in chronic kidney disease (CKD), including diabetic kidney disease (DKD) and obstructive nephropathy. Multiple microRNAs have been implicated in the pathogenesis of both DKD and obstructive nephropathy, although the overall role of microRNAs in tubular injury and renal fibrosis in CKD is unclear. Dicer (a key RNase III enzyme for microRNA biogenesis) was specifically ablated from kidney proximal tubules in mice via the Cre-lox system to deplete micoRNAs. Proximal tubular Dicer knockout (PT- Dicer KO) mice and wild-type (WT) littermates were subjected to streptozotocin (STZ) treatment to induce DKD or unilateral ureteral obstruction (UUO) to induce obstructive nephropathy. Renal hypertrophy, renal tubular apoptosis, kidney inflammation, and tubulointerstitial fibrosis were examined. Compared with WT mice, PT- Dicer KO mice showed more severe tubular injury and renal inflammation following STZ treatment. These mice also developed higher levels of tubolointerstitial fibrosis. Meanwhile, PT- Dicer KO mice had a significantly higher Smad2/3 expression in kidneys than WT mice (at 6 mo of age) in both control and STZ-treated mice. Similarly, UUO induced more severe renal injury, inflammation, and interstitial fibrosis in PT- Dicer KO mice than WT. Although we did not detect obvious Smad2/3 expression in sham-operated mice (2-3 mo old), significantly more Smad2/3 was induced in obstructed PT- Dicer KO kidneys. These results supported a protective role of Dicer-dependent microRNA synthesis in renal injury and fibrosis development in CKD, specifically in DKD and obstructive nephropathy. Depletion of Dicer and microRNAs may upregulate Smad2/3-related signaling pathway to enhance the progression of CKD.

Identification of methylated genes and miRNA signatures in nasopharyngeal carcinoma by bioinformatics analysis

Nasopharyngeal carcinoma (NPC) is prevalent in several regions, including. Southern China and Southeast Asia, with high mortality. The present study aimed to explore the epigenetic mechanisms of NPC and to provide novel biomarkers for prognosis. Two methylation data sets (GSE52068 and GSE62336) were downloaded from the Gene Expression Omnibus database. Following pretreatment of the raw data, differentially methylated regions (DMRs) and differentially methylated CpG islands (DMCs) were identified between the NPC samples and normal tissue controls using COHCAP software. The overlapped DMRs and DMCs in the two data sets were extracted and associated to relevant genes. Enrichment analysis and protein-protein interaction (PPI) network analyses were performed on the identified genes using Database for Annotation, Visualization and Integration Discovery and Cytoscape, respectively. MicroRNAs (miRNAs) targeting the overlapped genes were identified based on the miRWalk database. NPC-related genes were analyzed with the Comparative Toxicogenomics Database. Multiple overlapping DMRs between the two data sets were identified and were associated with 1,854 hypermethylated and 18 hypomethylated genes, which were revealed to be enriched in certain pathways, including the mitogen-activated protein kinase (MAPK) signaling pathway and the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway. Several nodes in the predicted PPI network were highlighted, including proto-oncogene tyrosine-protein kinase SRC, SMAD family member 3 (SMAD3), tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein ζ (YWHAZ) and Heat shock protein family A member 4 (HSPA4), all of which were hypomethylated. A total of 14 miRNAs were identified that correlated with the overlapped genes such as miRNA (miR)-148a-3p, which was predicted to target of HSPA4; and 17 genes were identified as related to NPC, including SMAD3 and SRC. miR129-2 was hypermethylated. Several novel methylated genes or miRNAs were suggested as biomarkers for NPC prognosis: Hypomethylation of SRC, SMAD3, YWHAZ and HSPA4, and hypermethylation of miR129-2 may be linked to poor prognosis of NPC.

Long non-coding RNA XIST promotes TGF-β-induced epithelial-mesenchymal transition by regulating miR-367/141-ZEB2 axis in non-small-cell lung cancer

Growing evidence shows that lncRNA XIST functions as an oncogene accelerating tumor progression. Transforming growth factor β (TGF-β)-induced epithelial-mesenchymal transition (EMT) plays a key role in tumor metastasis. However, it is still unclear whether lncRNA XIST is implicated in TGF-β-induced EMT and influences cell invasion and metastasis in non-small-cell lung cancer (NSCLC). Here, we observed increased expression of lncRNA XIST and ZEB2 mRNA in metastatic NSCLC tissues. Knockdown of lncRNA XIST inhibited ZEB2 expression, and repressed TGF-β-induced EMT and NSCLC cell migration and invasion. Being in consistent with the in vitro findings, the in vivo experiment of metastasis showed that knockdown of lncRNA XIST inhibited pulmonary metastasis of NSCLC cells in mice. In addition, knockdown of ZEB2 expression can inhibit TGF-β-induced EMT and NSCLC cell migration and invasion. Mechanistically, lncRNA XIST and ZEB2 were targets of miR-367 and miR-141. Furthermore, both miR-367 and miR-141 expression can be upregulated by knockdown of lncRNA XIST. Taken together, our study reveals that lncRNA XIST can promote TGF-β-induced EMT and cell invasion and metastasis by regulating miR-367/miR-141-ZEB2 axis in NSCLC.

MicroRNA-92b inhibits epithelial-mesenchymal transition-induced migration and invasion by targeting Smad3 in nasopharyngeal cancer

Increasing studies reports that aberrant miRNAs contribute to nasopharyngeal carcinoma (NPC) development and progression. However, the role of miR-92b in NPC remains unclear. In present research, we found that a reduced miR-92b expression in NPC tissues and cell lines. The clinical data showed that the down-regulated miR-92b expression was obviously associated with adverse prognostic characteristic. Furthermore, we confirmed that miR-92b was a novel independent prognostic symbol for predicting 5-year survival of NPC patients. MiR-92b overexpression inhibited cell migration, invasion and EMT progress, while down-regulated miR-92b reversed the effect. Besides, miR-92b could modulate Smad3 by directly binding to its 3’-UTR. In clinical samples of NPC, miR-92b inversely correlated with Smad3. Alternation of Smad3 expression at least partially abrogated the migration, invasion and EMT progress of miR-92b on NPC cells. In summary, our results indicated that miR-92b functioned as a tumor suppressor gene in regulating the EMT and metastasis of NPC via targeting Smad3, and may represent a novel potential therapeutic target and prognostic marker for NPC.

miRNA-708 functions as a tumour suppressor in hepatocellular carcinoma by targeting SMAD3

Hepatocellular carcinoma (HCC) is the most frequent subtype of primary liver cancer and the third most common cause of cancer-associated mortality worldwide. Previous studies have reported that microRNAs (miRNAs) serve key roles in the carcinogenesis and progression of HCC by regulating gene expression. The present study investigated the expression patterns, biological roles and underlying mechanisms of miRNA-708 (miR-708) in HCC. The expression levels of miR-708 in HCC tissue samples and cell lines were examined. Cell proliferation, migration and invasion assays were used to evaluate the effect of miR-708 on HCC cells. In addition, bioinformatic and western blotting analyses, and dual luciferase reporter assays were performed to investigate the direct gene target of miR-708. The results of the present study demonstrated that miR-708 expression was significantly decreased in HCC tissue samples and cell lines. In addition, the expression level of miR-708 was associated with increased HCC tumour stage. Furthermore, ectopic expression of miR-708 suppressed HCC cell proliferation, migration and invasion. The results of the present study also indicated that miR-708 targets SMAD family member 3 directly in vitro. The results of the present study indicated that miR-708 may be a novel target for future HCC therapy.

miR-324-3p suppresses migration and invasion by targeting WNT2B in nasopharyngeal carcinoma

Background

Nasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma of the head and neck with strong ability of invasion and metastasis. Our previous study indicated that miR-324-3p, as a tumor-suppressive factor, could regulate radioresistance of NPC cells by targeting WNT2B. The purpose of this study is to investigate the role of miR-324-3p on migration and invasion in NPC cells.

Methods

Quantitative real time PCR was applied to measure the expression level of miR-324-3p and WNT2B mRNA in both cells and tissues, and the expression level of WNT2B protein was determined by western blotting. The capacity of migration and invasion were tested by using wound healing and transwell invasion assay.

Results

Ectopic expression of miR-324-3p or silencing its target gene WNT2B could dramatically suppress migration and invasion capacity of NPC cells. Meanwhile, the alterations of miR-324-3p in NPC cells could influence the expression level of the biomarkers of epithelial-mesenchymal transition (EMT), including E-cadherin and Vimentin. Moreover, the expression of miR-324-3p was obviously downregulated and WNT2B was significantly upregulated in NPC tissues. The expression levels of miR-324-3p and WNT2B were closely correlated with T stage, clinic stage and cervical lymph node metastasis of NPC (P < 0.05).

Conclusion

miR-324-3p could suppress the migration and invasion of NPC by targeting WNT2B and the miR-324-3p/WNT2B pathway possibly provide new potential therapeutic clues for NPC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-016-0372-8) contains supplementary material, which is available to authorized users.

The Signature of MicroRNA Dysregulation in Muscle Paralyzed by Spinal Cord Injury Includes Downregulation of MicroRNAs that Target Myostatin Signaling

Spinal cord injury (SCI) results in muscle atrophy, reduced force generation and an oxidative-to-glycolytic fiber type shift. The mechanisms responsible for these alterations remain incompletely understood. To gain new insights regarding mechanisms involved in deterioration of muscle after SCI, global expression profiles of miRs in paralyzed gastrocnemius muscle were compared between sham-operated (Sham) and spinal cord-transected (SCI) rats. Ingenuity Pathways Analysis of the altered miRs identified signaling via insulin, IGF-1, integrins and TGF-β as being significantly enriched for target genes. By qPCR, miRs 23a, 23b, 27b, 145, and 206, were downregulated in skeletal muscle 56 days after SCI. Using FISH, miR-145, a miR not previously implicated in the function of skeletal muscle, was found to be localized to skeletal muscle fibers. One predicted target of miR-145 was Cited2, a transcriptional regulator that modulates signaling through NF-κB, Smad3 and other transcription factors. The 3’ UTR of Cited2 mRNA contained a highly conserved miR-145 seed sequence. Luciferase reporter assays confirmed that miR-145 interacts with this seed sequence. However, Cited2 protein levels were similar between Sham and SCI groups, indicating a biochemical interaction that was not involved in the context of adaptations after SCI. Taken together, the findings indicate dysregulation of several highly expressed miRs in skeletal muscle after SCI and suggest that reduced expression of miR-23a, 145 and 206 may have roles in alteration in skeletal muscle mass and insulin responsiveness in muscle paralyzed by upper motor neuron injuries.

Airway smooth muscle inflammation is regulated by microRNA-145 in COPD

Chronic obstructive pulmonary disease (COPD) is a common, highly debilitating disease of the airways, primarily caused by smoking. Chronic inflammation and structural remodelling are key pathological features of this disease, in part caused by the aberrant function of airway smooth muscle (ASM) cells under the regulation of transforming growth factor (TGF)-β. miRNA are short, noncoding gene transcripts involved in the negative regulation of specific target genes, through their interactions with mRNA. Previous studies have proposed that mRNA-145 (miR-145) may interact with SMAD3, an important downstream signalling molecule of the TGF-β pathway. TGF-β was used to stimulate primary human ASM cells isolated from healthy nonsmokers, healthy smokers and COPD patients. This resulted in a TGF-β-dependent increase in CXCL8 and IL-6 release, most notably in the cells from COPD patients. TGF-β stimulation increased SMAD3 expression, only in cells from COPD patients, with a concurrent increased miR-145 expression. Regulation of miR-145 was found to be negatively controlled by pathways involving the MAP kinases, MEK-1/2 and p38 MAPK. Subsequent, overexpression of miR-145 (using synthetic mimics) in ASM cells from patients with COPD suppressed IL-6 and CXCL8 release, to levels comparable to the nonsmoker controls. Therefore, this study suggests that miR-145 negatively regulates pro-inflammatory cytokine release from ASM cells in COPD by targeting SMAD3.

MiR-145 and miR-203 represses TGF-β-induced epithelial-mesenchymal transition and invasion by inhibiting SMAD3 in non-small cell lung cancer cells

OBJECTIVES

MicroRNAs (miRNAs) have been proved to play important role in development of various cancers, including non-small cell lung cancer (NSCLC). Our previous studies have shown that miR-203 and miR-145 are associated with cellular invasion in NSCLC and nasopharyngeal cancer, respectively. However, the mechanistic role of miR-203 and miR-145 in TGF-β-induced epithelial-mesenchymal transition (EMT) has not yet been elucidated in human cancers, including NSCLC.

MATERIALS AND METHODS

Real-time quantitative reverse transcriptase PCR (qRT-PCR), western blot analysis, luciferase reporter gene assays, small RNA interference and transwell migration and invasion assays were carried on human NSCLC cell lines A549 and 95C. Thirty-six paired NSCLC tissues and adjacent noncancerous lung tissues were collected.

RESULTS

Both miR-145 and miR-203 can directly target the 3'-untranslated region (3'-UTR) of SMAD3, and overexpression of the two miRNAs in NSCLC cells inhibited the expression of SMAD3 mRNA and protein, whereas inhibition of endogenous miR-145 or miR-203 caused an increased expression of SMAD3. Moreover, miR-145 and/or miR-203 repressed TGF-β-induced EMT and attenuated cell migration and invasion in A549 and 95C cells. siRNA-mediated knockdown of SMAD3 copied the phenotype of miR-145 and miR-203 overexpression in A549 and 95C cells.

CONCLUSION

MiR-145 and miR-203 inhibited TGF-β-induced EMT and invasion through repression of SMAD3 in NSCLC cells. Our findings provided insights into the miRNA-based mechanism for controlling TGF-β-induced EMT of NSCLC cells and a strategy for targeted therapy of NSCLC.

Role and mechanism of miR-222 in arsenic-transformed cells for inducing tumor growth

High levels of arsenic in drinking water, soil, and air are associated with the higher incidences of several kinds of cancers worldwide, but the mechanism is yet to be fully discovered. Recently, a number of evidences show that dysregulation of microRNAs (miRNAs) induces carcinogenesis. In this study, we found miR-222 was upregulated in arsenic-transformed human lung epithelial BEAS-2B cells (As-T cells). Anti-miR-222 inhibitor treatment decreased cell proliferation, migration, tube formation, and induced apoptosis. In addition, anti-miR-222 inhibitor expression decreased tumor growth in vivo. We also found that inhibition of miR-222 induced the expression of its direct targets ARID1A and phosphatase and tensin homolog deleted on chromosome 10 (PTEN), and activated apoptosis of As-T cells in part through ARID1A downregulation. These results indicate that miR-222 plays an important role in arsenic-induced tumor growth.