MicroRNA-429 suppresses cell proliferation, epithelial-mesenchymal transition, and metastasis by direct targeting of BMI1 and E2F3 in renal cell carcinoma

Epithelial-mesenchymal transition associated markers in sarcomatoid transformation of clear cell renal cell carcinoma

Epithelial-mesenchymal transition (EMT) plays a pivotal role in the development and progression of many cancers. Partial EMT (pEMT) could represent a critical step in tumor migration and dissemination. Sarcomatoid renal cell carcinoma (sRCC) is an aggressive form of renal cell carcinoma (RCC) composed of a carcinomatous (sRCC-Ca) and sarcomatous (sRCC-Sa) component. The role of (p)EMT in the progression of RCC to sRCC remains unclear. The aim of this study was to investigate the involvement of (p)EMT in RCC and sRCC. Tissue samples from 10 patients with clear cell RCC (ccRCC) and 10 patients with sRCC were selected. The expression of main EMT markers (miR-200 family, miR-205, SNAI1/2, TWIST1/2, ZEB1/2, CDH1/2, VIM) was analyzed by qPCR in ccRCC, sRCC-Ca, and sRCC-Sa and compared to non-neoplastic tissue and between both groups. Expression of E-cadherin, N-cadherin, vimentin and ZEB2 was analyzed using immunohistochemistry. miR-200c was downregulated in sRCC-Ca compared to ccRCC, while miR-200a was downregulated in sRCC-Sa compared to ccRCC. CDH1 was downregulated in sRCC-Sa when compared to any other group. ZEB2 was downregulated in ccRCC and sRCC compared to corresponding non-neoplastic kidney. A positive correlation was observed between CDH1 expression and miR-200a/b/c. Our results suggest that full EMT is not present in sRCC. Instead, discreet molecular differences exist between ccRCC, sRCC-Ca, and sRCC-Sa, possibly representing distinct intermediary states undergoing pEMT.

Profiling of Serum miRNAs Constructs a Diagnostic 3-miRNA Panel for Clear-Cell Renal Cell Carcinoma

BACKGROUND

Renal cell carcinoma (RCC) carries significant morbidity and mortality globally with an increasing incidence per year predominantly represented by clear-cell renal cell carcinoma (ccRCC) which accounts for 70-80% of all RCC cases. MicroRNAs(miRNAs) implicate tumor development and progression in epigenetic mechanisms and available profiling of serum miRNAs potentiate them as diagnostic markers for various cancers.

MATERIALS AND METHODS

A total of 108 ccRCC patients and 112 normal controls were enrolled. A 3-stage experiment was conducted to identify differentially expressed serum miRNAs in ccRCC and establish a diagnostic miRNAs panel. Additionally, bioinformatic analysis was employed to predict selected miRNAs' target genes, preform functional annotation and explore the roles in ccRCC.

RESULTS

MiR-429, miR-10a-5p, miR-154-5p were found to be up-regulated miRNAs. Inversely, miR-27a-3p and miR-221-3p were found to be down-regulated miRNAs. These 5 miRNAs were selected to construct diagnostic panel by backward stepwise logistic regression analysis and ultimately a 3-miRNA panel (miR-429, miR-10a-5p and miR-27a-3p) was established [area under the curve (AUC) = 0.897, sensitivity = 85.0%, specificity = 83.3%].

CONCLUSION

The panel of 3-miRNA holds promise as a novel, convenient, and noninvasive diagnostic method for early detection of ccRCC.

miR-429 Suppresses Endometrial Cancer Progression and Drug Resistance via DDX53

(1) Background: To examine miR-429-meditated DEAD (Asp-Glu-Ala-Asp) box polypeptide 53 (DDX53) function in endometrial cancer (EC). (2) Methods: DDX53 and miR-429 levels were measured using quantitative real-time polymerase chain reaction and western blotting assays, cell invasion and migration using Transwell invasion and wound healing assays, and cell proliferation using colony-forming/proliferation assays. A murine xenograft model was also generated to examine miR-429 and DDX53 functions in vivo. (3) Results: DDX53 overexpression (OE) promoted key cancer phenotypes (proliferation, migration, and invasion) in EC, while in vivo, DDX53 OE hindered tumor growth in the murine xenograft model. Moreover, miR-429 was identified as a novel miRNA-targeting DDX53, which suppressed EC proliferation and invasion. (4) Conclusions: DDX53 and miR-429 regulatory mechanisms could provide novel molecular therapies for EC.

HIF-1-Induced hsa-miR-429: Understanding Its Direct Targets as the Key to Developing Cancer Diagnostics and Therapies

MicroRNAs (miRNAs) play a critical role in the regulation of mRNA stability and translation. In spite of our present knowledge on the mechanisms of mRNA regulation by miRNAs, the utilization and translation of these ncRNAs into clinical applications have been problematic. Using hsa-miR-429 as an example, we discuss the limitations encountered in the development of efficient miRNA-related therapies and diagnostic approaches. The miR-200 family members, which include hsa-miR-429, have been shown to be dysregulated in different types of cancer. Although these miR-200 family members have been shown to function in suppressing epithelial-to-mesenchymal transition, tumor metastasis, and chemoresistance, the experimental results have often been contradictory. These complications involve not only the complex networks involving these noncoding RNAs, but also the problem of identifying false positives. To overcome these limitations, a more comprehensive research strategy is needed to increase our understanding of the mechanisms underlying their biological role in mRNA regulation. Here, we provide a literature analysis of the verified hsa-miR-429 targets in various human research models. A meta-analysis of this work is presented to provide better insights into the role of hsa-miR-429 in cancer diagnosis and any potential therapeutic approach.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

E2F1/2/4 mRNA is associated with immune infiltration and are potential biomarkers for the prognosis of human gastric carcinoma

Background

E2Fs are genes that regulate DNA synthesis and the cell cycle by encoding a family of transcription factors. Increasing experimental evidence has revealed that E2Fs play key roles in tumor progression in various types of cancer.

Methods

We investigated the survival, expression and transcriptional data of E2F1/2/4 in gastric cancer (GC) patients using the immunohistochemistry assay, Kaplan-Meier Plotter, cBioPortal, String, and GEPIA databases. The plasma of GC patients was analyzed using the real-time reverse transcription polymerase chain reaction (RT-PCR) assay. The correlation between E2F1/2/4 expression and clinical features was analyzed using the quartile method. As well, the correlation between E2F1/2/4 and GC immune infiltration was also investigated using the TIMER database. Database of Immune Cell Expression (DICE) was also used to analyze correlations between SOX4 and immune responses.

Results

RT-PCR and tissue immunohistochemistry confirmed that E2F1/2/4 was highly expressed in serum and GC tissue samples of GC patients, the expression of which was not affected by patient age and gender. Also, the survival analysis revealed that low levels of E2F1/2/4 expression were significantly associated with a longer overall survival (OS) in GC patients. E2F1/2/4 was correlated with patient prognosis and immune cell infiltration, including B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages, neutrophils, and DCs in GC. Our findings indicated that E2F1/2/4 could be used as a prognostic biomarker and indicator of immune infiltration in GC.

Conclusions

This study revealed that E2F1/2/4 could be a promising indicator for tumor-associated immune infiltration and prognosis in GC patients.

miRNA-200c-3p targets talin-1 to regulate integrin-mediated cell adhesion

The ability of integrins on the cell surface to mediate cell adhesion to the extracellular matrix ligands is regulated by intracellular signaling cascades. During this signaling process, the talin (TLN) recruited to integrin cytoplasmic tails plays the critical role of the major adaptor protein to trigger integrin activation. Thus, intracellular levels of TLN are thought to determine integrin-mediated cellular functions. However, the epigenetic regulation of TLN expression and consequent modulation of integrin activation remain to be elucidated. Bioinformatics analysis led us to consider miR-200c-3p as a TLN1-targeting miRNA. To test this, we have generated miR-200c-3p-overexpressing and miR-200c-3p-underexpressing  cell lines, including HEK293T, HCT116, and LNCaP cells. Overexpression of miR-200c-3p resulted in a remarkable decrease in the expression of TLN1, which was associated with the suppression of integrin-mediated cell adhesion to fibronectin. In contrast, the reduction in endogenous miR-200c-3p levels led to increased expression of TLN1 and enhanced cell adhesion to fibronectin and focal adhesion plaques formation. Moreover, miR-200c-3p was found to target TLN1 by binding to its 3′-untranslated region (UTR). Taken together, our data indicate that miR-200c-3p contributes to the regulation of integrin activation and cell adhesion via the targeting of TLN1.

The microRNA cluster miR-214/miR-3120 prevents tumor cell switching from an epithelial to a mesenchymal-like phenotype and inhibits autophagy in gallbladder cancer

Tumor cells switch from an epithelial to a mesenchymal-like phenotype, which represents a key hallmark of human cancer metastasis, including gallbladder cancer (GBC). A large set of microRNAs (miRNAs/miRs) have been studied to elucidate their functions in initiating or inhibiting this phenotypic switching in GBC cells. In this paper, we attempted to identify the expression pattern of the miR-214/-3120 cluster and its mode of action in the context of GBC, with a specific focus being placed on their effects on EMT and autophagy in GBC cells. Human GBC cells GBC-SD were assayed for their migration, invasion, and autophagy using the Transwell chamber system, MDC staining, and transmission electron microscopy. The tumorigenicity and metastatic behavior of GBC-SD cells were tested in nude mice. The expression of EMT- and autophagy-specific markers (E-cadherin, N-cadherin, vimentin, ATG5, LC3II/LC3I, and Beclin1) was analyzed in cultured GBC-SD cells and in human GBC-SD xenografts. The E2F3 luciferase reporter activity in the presence of miR-214/-3120 was evaluated by a dual luciferase assay. The miR-214/-3120 was downregulated in GBC. Exogenous miR-214/-3120 inhibited the phenotypic switching of GBC cells from epithelial to mesenchymal, prevented autophagy, and suppressed the tumorigenicity and metastatic behavior of GBC-SD cells in vitro and in vivo. E2F3 was demonstrated to be the target gene of miR-214/-3120, and its knockdown in part mimicked the effect of miR-214/-3120 on the EMT, autophagy, tumorigenicity, and metastatic behavior of GBC-SD cells. These results demonstrated that the miR-214/-3120 cluster blocks the process of EMT and autophagy to limit GBC metastasis by repressing E2F3 expression.

Bioinformatic gene analysis for possible biomarkers and therapeutic targets of hypertension-related renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is one of the most prevalent malignant tumors of the urinary system. Hypertension can cause hypertensive nephropathy (HN). Meanwhile, Hypertension is considered to be related to kidney cancer. We analyzed co-expressed genes to find out the relationship between hypertension and RCC and show possible biomarkers and novel therapeutic targets of hypertension-related RCC.

METHODS

We identified the differentially expressed genes (DEGs) of HN and RCC through analyzing Gene Expression Omnibus (GEO) datasets GSE99339, GSE99325, GSE53757 and GSE15641 by means of bioinformatics analysis, respectively. Then we evaluated these genes with protein-protein interaction (PPI) networks, Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and CTD database. Subsequently, we verified co-expressed DEGs with Gene Expression Profiling Interactive Analysis (GEPIA) database. Finally, corresponding predicted miRNAs of co-expressed DEGs were identified and verified via mirDIP database and Starbase, respectively.

RESULTS

We identified 9 co-expressed DEGs, including BCAT1, CORO1A, CRIP1, ESRRG, FN1, LYZ, PYCARD, SAP30, and PTRF. CRIP1 and ESRRG and their corresponding predicted miRNAs, especially hsa-miR-221-5p, hsa-miR-205-5p, hsa-miR-152-3p and hsa-miR-137 may be notably related to hypertension-related RCC.

CONCLUSIONS

CRIP1 and ESRRG genes have great potential to become novel biomarkers and therapeutic targets concerning hypertension-related RCC.

A novel ETV6-miR-429-CRKL regulatory circuitry contributes to aggressiveness of hepatocellular carcinoma

BACKGROUND

Tumor metastasis is one of the main causes of the high mortality of hepatocellular carcinoma (HCC). E-Twenty Six variant gene 6 (ETV6) is a strong transcriptional repressor, associated with the development and progression of tumors. However, the exact role and underlying mechanism of ETV6 in HCC remain unclear.

METHODS

Western blotting, quantitative real-time PCR and immunohistochemistry were used to detect the expression levels of ETV6, CRKL (v-crk sarcoma virus CT10 oncogene homologue (avian)-like) and miR-429 in HCC tissues and cells; Transwell chamber and F-actin cytoskeleton staining assay to examine the effects of ETV6 and CRKL deregulation on the migration, invasion and cytoskeleton of HCC cells; Co-immunoprecipitation assay to determine the interaction between CRKL and ETV6; Chromatin immunoprecipitation assay to investigate the interaction between ETV6 and miR-429.

RESULTS

We established a novel ETV6-miR-429-CRKL regulatory circuitry contributes to HCC metastasis. ETV6 and CRKL were frequently increased, while miR-429 was downregulated in both hepatocarcinoma tissues and hepatocarcinoma cells. Moreover, ETV6 upregulation was positively correlated with CRKL upregulation, and two negative correlations were also established for ETV6 and CRKL upregulation with miR-429 downregulation in both hepatocarcinoma patients' tumorous tissues and hepatocarcinoma cells. Functional investigations revealed that overexpression and knockdown of ETV6 was remarkably effective in promoting and suppressing HCC cell migration, invasion, cytoskeleton F-actin expression and arrangement, whereas, CRKL overexpression exhibited similar effects to the overexpression of ETV6. Mechanistically, ETV6 negatively regulates miR-429 expression by directly binding to the promoter region of miR-429; miR-429 negatively regulates CRKL expression by selectively targeting CRKL-3'-UTR; ETV6 directly binds to CRKL and positively regulates its expression, which in turn CRKL positively regulates ETV6 expression.

CONCLUSIONS

Our data demonstrated that ETV6 promotes migration and invasion of HCC cells by directly binding to promoter region of miR-429 via modulating CRKL expression. The newly identified ETV6-miR-429-CRKL regulatory circuitry contributes to the aggressiveness of HCC, which provides new clues for fundamental research on diagnosis and treatment parameters for HCC.

miR‑215 promotes epithelial to mesenchymal transition and proliferation by regulating LEFTY2 in endometrial cancer

Endometrial cancer (EC) is the most common gynecological tumor in developed countries with an increasing incidence. Left-right determination factor 2 (LEFTY2), a suppressor of cell proliferation and tumor growth, is a negative regulator of EC progression. The roles of LEFTY2 are emerging; however, the regulatory mechanisms of its expression have not been well understood. MicroRNA (miR)-215 as an oncogene serves an important role in tumorigenesis by regulating target genes. In the present study, it was demonstrated that overexpression of miR-215 promoted epithelial to mesenchymal transition (EMT), colony formation and DNA synthesis in EC HEC-1A cells and its expression was upregulated in EC tissues. Using online miR target prediction software, it was revealed that LEFTY2 is predicted as a target of miR-215. Using western blot analysis and immunofluorescence assays, it was demonstrated that overexpression of miR-215 markedly downregulated LEFTY2 protein expression levels in HEC-1A cells and LEFTY2 protein expression was downregulated in EC tissues, which was inversely correlated with miR-215 expression. Furthermore, the present study indicated that overexpression of LEFTY2 protein promoted mesenchymal to epithelial transition and sensitized HEC-1A cells to cisplatin treatment. In addition, it was revealed that the overexpression of LEFTY2 inhibited colony formation and DNA synthesis in HEC-1A cells. Thus, miR-215 may promote EMT and proliferation by regulating LEFTY2 in EC.

miR-429 expression in bladder cancer and its correlation with tumor behavior and clinical outcome

We previously showed that microRNA-429 (miR-429) played an important role in epithelial-mesenchymal transition (EMT) of urothelial cell carcinoma of the bladder. We herein evaluated the expression of miR-429 in bladder cancer and its potential relevance to clinicopathological characteristics and patient survival. Relative expression levels of miR-429 in surgical bladder cancer tissue specimens obtained from 76 patients with bladder cancer were measured by chromogenic in situ hybridization. miR-429 expression was significantly higher in specimens from alive patients than expired patients in both of 5-year overall survival (OS) (0.59 ± 0.09 vs. 0.27 ± 0.12; p < 0.05) and 5-year recurrence-free survival (RFS) (0.63 ± 0.10 vs. 0.33 ± 0.10; p < 0.05). The univariate Cox proportional hazards analysis revealed that tumor grade, stage, and miR-429 expression were significantly associated with patient survival. In multivariate analysis, tumor stage and miR-429 expression were significantly associated with 5-year OS (hazard ratio [HR] 4.70, p < 0.001) and 5-year-RFS (HR 2.20, p < 0.05). The Kaplan-Meier analysis showed that patients with miR-429 expression had significantly better 5-year OS and 5-year RFS rates than those without miR-429 expression (84.4% vs. 61.4%, p < 0.05 and 71.9% vs. 45.5%, p < 0.05, respectively). miR-429 may be considered as an adjunctive prognostic marker in addition to tumor grade and stage in bladder cancer.

MiR-429 reverses epithelial-mesenchymal transition by restoring E-cadherin expression in bladder cancer

Epithelial-mesenchymal transition (EMT) accompanying loss of E-cadherin is important for invasiveness and metastasis of bladder cancer. MicroRNAs (miRs) had been associated with cancer progression and differentiation in several cancers. Our goal is to find out the specific miR which modulates EMT in bladder cancer. Real-time quantitative polymerase chain reaction was used to measure the miRs expression in urothelial cell carcinoma (UCC) cell lines. MiR or siRNA mimics was used to regulate miR and mRNA level respectively. Migration and scratch assays were used to determine the migratory ability. Zymography assay was used to confirm the metalloproteinase activity. Western blotting was used to elucidate the mechanism which regulated by specific miR. MiR-429 was highly expressed in low grade UCC cell lines. Exogenous mimic of miR-429 treatment dramatically inhibited the migratory ability of T24 cells. MiR-429 downstream target ZEB1 was decreased, E-cadherin was restored, and β-catenin was contrarily decreased by exogenous mimic of miR-429 treatment in T24 cells. Cell invasive ability was also inhibited by exogenous mimic of miR-429 treatment through inactivating the MMP-2 activity in T24 cells. E-cadherin protein expression level was inhibited by E-cadherin siRNA accompanied with increasing cell migratory ability when compared with control group in low grade TSGH8301 cells. MiR-429 decreased the cell migratory and invasive abilities through reducing ZEB1 and β-catenin, restoring the E-cadherin expression and inactivation of MMP-2 of UCC cells. MiR-429 might be used as a progression marker of bladder cancer.

Epigenetic regulation of miR-200 as the potential strategy for the therapy against triple-negative breast cancer

MicroRNAs (miRNAs) are a class of small, non-coding RNAs that are involved in the regulation of gene expression at the post-transcriptional level. MicroRNAs play an important role in cancer cell proliferation, survival and apoptosis. Epigenetic modifiers regulate the microRNA expression. Among the epigenetic players, histone deacetylases (HDACs) function as the key regulators of microRNA expression. Epigenetic machineries such as DNA and histone modifying enzymes and various microRNAs have been identified as the important contributors in cancer initiation and progression. Recent studies have shown that developing innovative microRNA-targeting therapies might improve the human health, specifically against the disease areas of high unmet medical need. Thus microRNA based therapeutics are gaining importance for anti-cancer therapy. Studies on Triple negative breast cancer (TNBC) have revealed the early relapse and poor overall survival of patients which needs immediate therapeutic attention. In this report, we focus the effect of HDAC inhibitors on TNBC cell proliferation, regulation of microRNA gene expression by a series of HDAC genes, chromatin epigenetics, epigenetic remodelling at miR-200 promoter and its modulation by various HDACs. We also discuss the need for identifying novel HDAC inhibitors for modulation of miR-200 in triple negative breast cancer.

lncRNA PVT1 and its splicing variant function as competing endogenous RNA to regulate clear cell renal cell carcinoma progression

Long non-coding RNAs (lncRNAs) exert critical regulatory roles in the development and progression of several cancers. Plasmacytoma variant translocation 1 (PVT1), an lncRNA, was shown to be upregulated in clear cell renal cell carcinoma (ccRCC) in our study, while Kaplan-Meier curve and Cox regression analysis showed that high expression of PVT1 was associated with poor overall survival (OS) and disease free survival (DFS) in ccRCC patients. In vitro experiments revealed that PVT1 promoted renal cancer cell proliferation, migration, and invasion, while in vivo studies confirmed its oncogenic roles in ccRCC. Further bioinformatic analysis and RNA immunoprecipitation revealed that PVT1 could function as an oncogenic transcript partly through sponging miR-200s to regulate BMI1, ZEB1 and ZEB2 expression. Besides, a novel splicing variant of PVT1 lacking exon 4 (PVT1ΔE4) was found to have a higher expression in ccRCC and could also promote cell proliferation and invasion as the full-length transcript did. Besides, SRSF1 decreased the inclusion of exon 4 of full-length transcript and increased the relative expression of PVT1ΔE4 in ccRCC. Mechanistic investigations indicated that PVT1ΔE4 could also upregulate the expression of BMI1, ZEB1 and ZEB2 through interacting with miR-200s. Our study helps reveal new molecular events in ccRCC and provides promising diagnostic and therapeutic targets for this disease.

Clinical performance of E2Fs 1-3 in kidney clear cell renal cancer, evidence from bioinformatics analysis

Extensive research on the E2F transcription factor family has led to numerous insights that E2Fs were involved not only in proliferation and tumorigenesis but also in apoptosis and differentiation. In the present study, we analyzed the differential expression of E2Fs1-3 genes, and also evaluated the impact of E2Fs 1-3 genes expression on clinical outcome from the Cancer Genome Atlas (TCGA) database. The results showed that E2F1, E2F2 and E2F3 expression was increased in KIRC tissues than matched normal tissues (E2F1, P < 0.001; E2F2, P < 0.001, E2F3, P = 0.001), respectively. E2F1, E2F2 and E2F3 were significantly different in metastasis status, lymph node status, stage, and T stage in KIRC patients (all P < 0.01). E2F1 and E2F2 had the sensitivity of 96.1% and 93.1% and the specificity of 87.2% and 91.7% in discriminating KIRC from normal controls. High E2F1, E2F2 and E2F3 expression were correlated to worsen overall survival (all P < 0.01), and high E2F3 expression had worse disease free survival (P = 0.0404). Multivariate Cox regression analysis revealed that E2F1 and E2F3 were independent prognostic factors for overall survival. Taken together, E2F1 and E2F2 may serve as valuable diagnostic markers for KIRC. Moreover, E2F1, E2F2 and E2F3 could provide valuable prognostic information for KIRC patients.

Tacrolimus induces fibroblasts apoptosis and reduces epidural fibrosis by regulating miR-429 and its target of RhoE

Tacrolimus (FK506) has been demonstrated to reduce epidural fibrosis. However, the detailed mechanism of action has not been elucidated. Aberrant miR-429 is involved in many diseases. The aim of this study was to describe the exact mechanism of FK506 induced apoptosis in fibroblasts and the prevention of epidural fibrosis. FK506 induced fibroblast apoptosis was evaluated using CCK-8 assays, flow cytometry, and western blotting. The expression of miR-429 in fibroblasts treated with FK506 was determined by RT-qPCR. Additionally, luciferase activity assays were used to determine the target relationship between miR-429 and RhoE. Flow cytometry and western blot analysis were used to determine the effects of FK506 and miR-429 on fibroblast apoptosis. The effects of FK506 and RhoE on fibroblast apoptosis were determined by CCK-8 assay, flow cytometry, and western blotting. We also evaluate the effects of FK506 and miR-429 on epidural fibrosis in rats by using histological analysis and TUNEL-staining. The results revealed FK506 induces fibroblast apoptosis and significantly downregulates miR-429 expression in fibroblasts. Additionally, miR-429 downregulation caused the apoptosis of fibroblasts. The luciferase activity assay confirmed that RhoE is a direct target of miR-429 and RhoE promotes fibroblast apoptosis. The rat model demonstrated miR-429 inhibition promotes fibroblast apoptosis and epidural fibrosis, which is consistent with the results of FK506 treatment. Our study demonstrates that FK506 induces fibroblast apoptosis and reduces epidural fibrosis by regulating miR-429 expression and its target of RhoE.

MiRNAs and E2F3: a complex network of reciprocal regulations in human cancers

E2F transcription factor 3 (E2F3) is oncogenic in tumorigenesis. Alterations in E2F3 functions correspond with poor prognosis in various cancers, underscoring their status for the clinical cancer phenotype. Latest reports discovered intricate networks between microRNAs (miRNAs) and E2F3 in regulating the balance of these events, including proliferation, apoptosis, metastasis, as well as drug resistance. miRNAs are non-coding small RNAs which negatively regulate gene expressions post-transcriptionally mainly through 3′-UTR binding of target mRNAs. Increasing evidence shows that E2F3 can be activated/inhibited by numerous miRNAs whose dysregulation has been implicated in malignancy. In turn, miRNAs themselves can be transcriptionally regulated by E2F3, thus forming a negative feedback loop. These findings add a new challenging layer of complexity to E2F3 network. Current understanding of the reciprocal link between E2F3 and miRNAs in human cancers were summarized, which could help to develop potential therapeutic strategies.

MicroRNA-194 represses glioma cell epithelial‑to‑mesenchymal transition by targeting Bmi1

MicroRNA-194 (miR-194) is frequently dysregulated in many types of cancer. However, the function of miR-194 in glioma remains unknown. In the present study, we aimed to investigate the biological functions of miR-194 in glioma and the potential molecular mechanism of miR-194 involved in glioma progression. We found that miR-194 expression was significantly reduced in glioma specimens and cell lines, as detected by real-time quantitative polymerase chain reaction (RT-qPCR) analysis. The overexpression of miR-194 inhibited while the suppression of miR-194 promoted cell migration, invasion and epithelial mesenchymal transition (EMT) in glioma cells. Bioinformatics analysis showed that the B cell-specific moloney murine leukemia virus insertion site 1 (Bmi1) was a direct target of miR-194, which was validated by dual-luciferase reporter assay, RT-qPCR and western blot analysis. The restoration of Bmi1 expression significantly abrogated the suppressive effect of miR-194 on glioma cell EMT. Taken together, the present study suggests that miR-194 inhibits glioma cell EMT by targeting Bmi1 providing novel insights into understanding the pathogenesis of glioma. The restoration of miR-194 may be a potential therapeutic strategy for glioma treatment.

miR-429 Inhibits Differentiation and Promotes Proliferation in Porcine Preadipocytes

MicroRNAs (miRNAs) are crucial regulatory molecules for adipogenesis. They contribute to the controlling of proliferation and differentiation of preadipocytes. Previous studies revealed an important role of miR-429 in cell invasion, migration, and apoptosis. Our previous work has shown that the expression of miR-429 in subcutaneous fat can be observed in newly born (3-day-old) Rongchang piglets rather than their adult counterparts (180-day-old). This expression pattern suggests that miR-429 might be functionally related to postnatal adipogenesis. However, we currently lack a mechanistic understanding of miR-429 within the context of preadipocyte differentiation. In this study, we investigated the function of miR-429 in porcine subcutaneous and intramuscular preadipocyte proliferation and differentiation. In our porcine preadipocyte differentiation model, miR-429 expression decreased remarkably upon adipogenic induction. Overexpression of miR-429 notably down-regulated the expression of adipogenic marker genes: PPARγ, aP2, FAS and impaired the triglyceride accumulation, while the expression of lipolytic gene ATGL was not affected. In addition, we observed that miR-429 significantly promoted the proliferation of porcine preadipocytes. We also found that miR-429 could directly bind to the 3′-UTRs of KLF9 and p27, which have been well documented to promote preadipocyte differentiation and repress cell cycle progression. Taken together, our data support a novel role of miR-429 in regulating porcine preadipocyte differentiation and proliferation, and KLF9 and p27 are potent targets of miR-429 during these processes.

Epithelial-mesenchymal transition-associated microRNA/mRNA signature is linked to metastasis and prognosis in clear-cell renal cell carcinoma

Clear-cell renal cell carcinomas (ccRCCs) are genetically heterogeneous tumors presenting diverse clinical courses. Epithelial-mesenchymal transition (EMT) is a crucial process involved in initiation of metastatic cascade. The aim of our study was to identify an integrated miRNA/mRNA signature associated with metastasis and prognosis in ccRCC through targeted approach based on analysis of miRNAs/mRNAs associated with EMT. A cohort of 230 ccRCC was included in our study and further divided into discovery, training and validation cohorts. EMT markers were evaluated in ccRCC tumor samples, which were grouped accordingly to EMT status. By use of large-scale miRNA/mRNA expression profiling, we identified miRNA/mRNA with significantly different expression in EMT-positive tumors and selected 41 miRNAs/mRNAs for training phase of the study to evaluate their diagnostic and prognostic potential. Fifteen miRNAs/mRNAs were analyzed in the validation phase, where all evaluated miRNA/mRNA candidates were confirmed to be significantly deregulated in tumor tissue. Some of them significantly differed in metastatic tumors, correlated with clinical stage, with Fuhrman grade and with overall survival. Further, we established an EMT-based stage-independent prognostic scoring system enabling identification of ccRCC patients at high-risk of cancer-related death. Finally, we confirmed involvement of miR-429 in EMT regulation in RCC cells in vitro.

Polycomb Protein BMI1 Regulates Osteogenic Differentiation of Human Adipose Tissue-Derived Mesenchymal Stem Cells Downstream of GSK3

Polycomb proteins such as the B lymphoma Mo-MLV insertion region 1 homolog (BMI1) are essential chromatin factors for the self-renewal and differentiation of embryonic and adult stem cells. BMI1 also plays a critical role in osteogenesis as Bmi1-deficient mice display a skeletal phenotype caused by the exhaustion of the mesenchymal stem cell pool. In this study, we have studied the role of BMI1 in the osteogenic differentiation of human adipose tissue-derived mesenchymal stem cells (hASCs). BMI1 protein, but not RNA levels, increases during in vitro osteogenic differentiation of hASCs. Overexpression of BMI1 leads to an osteogenic priming of hASCs under nondifferentiating conditions and enhanced osteogenesis upon differentiation, along with increased BMP2 and WNT11 expressions. Conversely, knockdown of BMI1 expression reduces osteogenic differentiation. Furthermore, our studies indicate that during osteogenic differentiation of hASCs, BMI1 is a downstream target of GSK3 signaling. BMI1, therefore, acts as a pro-osteogenic differentiation factor in hASCs and hence it is a promising target for active modulation of hASC-derived osteogenesis.

MicroRNA-22 functions as a tumor suppressor by targeting SIRT1 in renal cell carcinoma

Accumulating evidence demonstrates that microRNA-22 (miR-22) was deregulated in many types of cancers and was involved in various cellular processes related to carcinogenesis. However, the exact roles and mechanisms of miR-22 remain unknown in human renal cell carcinoma (RCC). Here, the relationship between miR-22 expression pattern and clinicopathological features of patients with EOC were determined by real-time quantitative RT-PCR (qRT-PCR). Furthermore, the role of miR-22 and possible molecular mechanisms in EOC were investigated by several in vitro approaches and in a nude mouse model. Results from qRT-PCR showed that miR-22 was significantly downregulated in RCC samples compared with corresponding non-cancerous tissues, which was significantly associated with tumor stage and lymph node metastasis. Functional study demonstrated that enforced overexpression of miR-22 in renal cancer cells inhibited proliferation, migration and invasion, and induced cell apoptosis in vitro, and suppressed tumor growth in vivo. In addition, SIRT1 was identified as a direct target of miR-22 by a luciferase reporter assay. Overexpression of miR-22 activated p53 and its downstream target p21 and PUMA, and the apoptosis markers cleaved CASP3 and PARP, and inhibited epithelial-mesenchymal transition (EMT). These findings showed that miR-22 functioned as tumor suppressor in RCC and blocked RCC growth and metastasis by directly targeting SIRT1 in RCC, indicating a potential novel therapeutic role in RCC treatment.