MicroRNAs as oncogenes or tumour suppressors in oesophageal cancer: potential biomarkers and therapeutic targets

PAQR4 oncogene: a novel target for cancer therapy

Despite decades of basic and clinical research and trials of promising new therapies, cancer remains a major cause of morbidity and mortality due to the emergence of drug resistance to anticancer drugs. These resistance events have a very well-understood underlying mechanism, and their therapeutic relevance has long been recognized. Thus, drug resistance continues to be a major obstacle to providing cancer patients with the intended "cure". PAQR4 (Progestin and AdipoQ Receptor Family Member 4) gene is a recently identified novel protein-coding gene associated with various human cancers and acts through different signaling pathways. PAQR4 has a significant influence on multiple proteins that may regulate various gene expressions and may develop chemoresistance. This review discusses the roles of PAQR4 in tumor immunity, carcinogenesis, and chemoresistance. This paper is the first review, discussing PAQR4 in the pathogenesis of cancer. The review further explores the PAQR4 as a potential target in various malignancies.

The Role of Autophagy in Human Uveal Melanoma and the Development of Potential Disease Biomarkers and Novel Therapeutic Paradigms

Autophagy is a form of programmed cell degradation that enables the maintenance of homeostasis in response to extracellular stress stimuli. Autophagy is primarily activated by starvation and mediates the degradation, removal, or recycling of cell cytoplasm, organelles, and intracellular components in eukaryotic cells. Autophagy is also involved in the pathogenesis of human diseases, including several cancers. Human uveal melanoma (UM) is the primary intraocular malignancy in adults and has an extremely poor prognosis; at present there are no effective therapies. Several studies have suggested that autophagy is important in UM. By understanding the mechanisms of activation of autophagy in UM it may be possible to develop biomarkers to provide more definitive disease prognoses and to identify potential drug targets for the development of new therapeutic strategies. This article reviews the current information regarding autophagy in UM that could facilitate biomarker and drug development.

Molecular Biology and Clinical Management of Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) is a highly lethal malignancy. Due to its rising incidence, EAC has become a severe health challenge in Western countries. Current treatment strategies are mainly chosen based on disease stage and clinical features, whereas the biological background is hardly considered. In this study, we performed a comprehensive review of existing studies and discussed how etiology, genetics and epigenetic characteristics, together with the tumor microenvironment, contribute to the malignant behavior and dismal prognosis of EAC. During the development of EAC, several intestinal-type proteins and signaling cascades are induced. The anti-inflammatory and immunosuppressive microenvironment is associated with poor survival. The accumulation of somatic mutations at the early phase and chromosomal structural rearrangements at relatively later time points contribute to the dynamic and heterogeneous genetic landscape of EAC. EAC is also characterized by frequent DNA methylation and dysregulation of microRNAs. We summarize the findings of dysregulations of specific cytokines, chemokines and immune cells in the tumor microenvironment and conclude that DNA methylation and microRNAs vary with each different phase of BE, LGD, HGD, early EAC and invasive EAC. Furthermore, we discuss the suitability of the currently employed therapies in the clinic and possible new therapies in the future. The development of targeted and immune therapies has been hampered by the heterogeneous genetic characteristics of EAC. In view of this, the up-to-date knowledge revealed by this work is absolutely important for future EAC studies and the discovery of new therapeutics.

LncRNA SEMA3B-AS1 inhibits breast cancer progression by targeting miR-3940/KLLN axis

Long noncoding RNAs (lncRNAs) play crucial regulatory roles in the progression of various cancers. However, the functional roles of lncRNAs in breast cancer remain unclear. In this study, we investigated the functional role of a novel long noncoding RNA SEMA3B-AS1 (lncRNA SEAS1) in breast cancer progression and the underlying mechanisms. SEAS1 was downregulated in the triple-negative breast cancer (TNBC) tissues compared with the para-carcinoma tissues, which was associated with poor prognosis of TNBC patients. We demonstrated that SEAS1 knockdown significantly increased the proliferation, migration, and invasion of TNBC cell lines, whereas SEAS1 overexpression reversed these effects. Bioinformatics analysis demonstrated that microRNA (miR)-3940-3p was a potential target of SEAS1. Mechanistically, RNA immunoprecipitation (RIP) and luciferase reporter assays confirmed that lncRNA SEMA3B-AS1 acted as sponge for miR-3940-3p, preventing the degradation of its target gene KLLN, which acts as a tumor-inhibiter in TNBC. Moreover, RNA pulldown, mass spectrometry, ChIP, and luciferase reporter assays confirmed that SMAD3 directly interacted with the promoter of SEAS1 and suppressed its transcription, thereby promoting TNBC progression. The clinical samples of TNBC confirmed SEAS1 was correlated inversely with lymphatic and distant metastasis. In conclusion, our findings reveal a novel pathway for TNBC progression via SMAD3/lncRNA SEAS1/miR-3940-3p/KLLN axis, and suggest that SEAS1 may serve as a potential biomarker and therapeutic target for TNBC.

Targeting Autophagy for Developing New Therapeutic Strategy in Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) is a prevalent cause of low back pain. IVDD is characterized by abnormal expression of extracellular matrix components such as collagen and aggrecan. In addition, it results in dysfunctional growth, senescence, and death of intervertebral cells. The biological pathways involved in the development and progression of IVDD are not fully understood. Therefore, a better understanding of the molecular mechanisms underlying IVDD could aid in the development of strategies for prevention and treatment. Autophagy is a cellular process that removes damaged proteins and dysfunctional organelles, and its dysfunction is linked to a variety of diseases, including IVDD and osteoarthritis. In this review, we describe recent research findings on the role of autophagy in IVDD pathogenesis and highlight autophagy-targeting molecules which can be exploited to treat IVDD. Many studies exhibit that autophagy protects against and postpones disc degeneration. Further research is needed to determine whether autophagy is required for cell integrity in intervertebral discs and to establish autophagy as a viable therapeutic target for IVDD.

Circ_0122396 Protects Human Lens Epithelial Cells from Hydrogen Peroxide-induced Injury by Binding to miR-15a-5p to Stimulate FGF1 Expression

BACKGROUND

Circular_0122396 (circ_0122396) has been reported to be downregulated in age-related cataract (ARC); however, the underlying mechanism remains unknown. The study aimed to reveal the role of circ_0122396 in ARC progression and underneath mechanism.

METHODS

Hydrogen peroxide (H₂O₂) was employed to induce lens epithelial cells (SRA01/04) injury. The RNA expression of circ_0122396, microRNA-15a-5p (miR-15a-5p) and fibroblast growth factor 1 (FGF1) was detected by quantitative real-time polymerase chain reaction. Protein expression was checked by western blot. Cell viability, proliferation and apoptosis were investigated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, 5-Ethynyl-29-deoxyuridine and flow cytometry analysis, respectively. Oxidative stress was evaluated by superoxide dismutase and catalase activity assay kits and lipid peroxidation malondialdehyde assay kit. Online databases and mechanism assays were used to predict and identify the relationship between miR-15a-5p and circ_0122396 or FGF1.

RESULTS

Circ_0122396 and FGF1 expression were significantly downregulated, but miR-15a-5p expression was upregulated in ARC tissues or/and H₂O₂-treated SRA01/04 cells in comparison with control groups. H₂O₂ treatment repressed cell proliferation and induced cell apoptosis and oxidative stress, which was attenuated after circ_0122396 overexpression. MiR-15a-5p, a target mRNA of circ_0122396, was found to participate in H₂O₂-triggered cell damage by interacting with circ_0122396. Additionally, FGF1 silencing attenuated miR-15a-5p inhibitors-mediated action. Importantly, circ_0122396 regulated FGF1 expression by interaction with miR-15a-5p in H₂O₂-treated SRA01/04 cells.

CONCLUSION

Circ_0122396 ameliorated H₂O₂-triggered cell injury by inducing FGF1 through sponging miR-15a-5p, providing a potential target for ARC therapy.

Development of a prognostic prediction model based on microRNA-1269a in esophageal cancer

BACKGROUND

Esophageal cancer (ESCA) is a heterogeneous cancer with variable outcomes that are challenging to predict. MicroRNA (miR)-1269a is a newly discovered non-coding RNA that shows promising prognostic prediction in other cancers, but its clinical value in ESCA remains unclear.

AIM

To explore the relationship between miR-1269a and its clinical value and to develop a nomogram to succinctly display this relationship.

METHODS

We analyzed the expression of miR-1269a in 125 ESCA tissue samples with complete clinical data and 52 normal tissue samples. We determined the prognostic value of miR-1269a for overall survival (OS) and cancer-specific survival (CSS) and evaluated the association between miR-1269a and clinical variables including tumor location, histologic grade, metastatic stage, and American Joint Committee on Cancer (AJCC) stage using multivariate Cox analysis. Additionally, we developed a nomogram for OS and CSS based on miR-1269a expression using age and AJCC stage and assessed its prognostic performance. Using Gene Ontology and Kyoto Encyclopedia of Gene and Genomes analyses, we predicted the target genes of miR-1269a and analyzed their potential function in caner development.

RESULTS

The expression of miR-1269a was significantly higher in ESCA patients than healthy controls. Patients with high expression of miR-1269a showed poor prognosis in OS and CSS, suffered increased rates of low differentiation and metastasis, and exhibited tumor stage T3 + T4, positive lymph stage, and AJCC stage III + IV. The area under the receiver operating characteristic curve of miR-1269a was 0.716 for OS and 0.764 for CSS. Multivariate Cox analysis revealed that AJCC stage and miR-1269a were independent factors for OS and CSS. Combing with age, we constructed a nomogram for prognostic prediction. Additionally, our nomogram showed excellent predictive performance for OS and CSS after 3 years and 5 years and was easy to use. Ultimately, the functional analysis suggested that miR-1269a was mostly involved in the PI3K-AKT signaling pathway.

CONCLUSION

miR-1269a can be used as a potential indicator for the prognosis of ESCA patients. We developed an easy-to-use nomogram with excellent ESCA prognostic prediction for clinical use.

Novel biomarkers for the diagnosis and prognosis of gallbladder cancer

Gallbladder cancer (GBC) is the most common form of biliary tract malignancy with a dismal prognosis. A poor outcome in patients with GBC is related to the aggressive nature of the tumor, delayed diagnosis, and a lack of reliable biomarkers and effective treatment. Therefore, early diagnosis and accurate disease assessment are crucial to prolonging the patient survival. Identification of novel prognostic and diagnostic biomarkers may help improve the early diagnostic rate and develop specific targeted treatments for patients with GBC. We herein review the novel biomarkers that may be associated with the diagnosis and prognosis in GBC and their potential clinical significance in the management of GBC.

Targeting deubiquitinating enzyme USP26 by microRNA-203 regulates Snail1's pro-metastatic functions in esophageal cancer

Background

Esophageal cancer is one of the most common cancers worldwide with poor prognosis and high mortality. The transcription factor SNAI1, encoding Snail1, is important for metastatic progression in esophageal cancer whereas the microRNA (miRNA)-203 has been shown to function as an inhibitor of metastasis in EC. The Snail1 protein is stabilized in EC partially by the deubiquitinating enzyme USP26; however, how USP26 is regulated is not completely known.

Methods

Expression of SNAI1 and USP26 messenger RNA (mRNA) and miR-203 was performed in datasets within The Cancer Genome Atlas and Gene Expression Omnibus, respectively. Expression of Snail1 and USP26 protein and miR-203 was determined in the normal esophageal cell line HET-1A and EC cell lines Kyse150 and TE-1 using western blot and quantitative polymerase chain reaction, respectively. TargetScan was used for in situ prediction of miR-203 targets and in vitro heterologous reporter assays using the wild-type and miR-203 seed mutant of the 3′ Untranslated region (UTR) of USP26 were used to investigate whether USP26 is a target of miR-203. Effects of increasing miR-203 using MIR203A/5P mimic on USP26 and Snail1 in the HET-1A, Kyse150 and TE-1 cell lines were performed using western blot and cycloheximide-based protein stability analysis. Effects of modulating miR-203 in Kyse150 and TE-1 cell lines on in vitro pro-metastatic effects were analyzed by invasion assay, scratch wound-healing assay, and chemosensitivity to 5-fluoruracil (5-FU). In vivo lung metastasis assay was used to study the effect of modulating miR-203 in Kyse150 cells.

Results

SNAI1 mRNA and HSA/MIR203 was higher and lower, respectively, in EC patients compared to tumor-adjacent normal tissues. No changes in expression of USP26 mRNA were observed in these datasets. MIR/203 expression was downregulated whereas protein expression of both Snail1 and USP26 were higher in EC cell lines Kyse150 and TE-1 compared to normal esophageal cell line HET-1A. USP26 was predicted as a potential target of miR-203 by TargetScan Release 2.0. Reporter assays confirmed USP26 as a target of miR-203 in the EC cell lines. Transfection of EC cell lines with MIR203 mimic decreased USP26 protein expression and Snail1 protein stability indicating the ability of miR-203 to regulate Snail1 protein levels via USP26. Exogenous increase in miR-203 in the EC cell lines significantly inhibited Snail-1 mediated in vitro pro-metastatic function of invasion, wound-healing, and increased chemosensitivity to 5-FU. Finally, overexpression of miR-203 inhibited in vivo lung metastasis of Kyse150 cells, which was reversed following overexpression of USP26, indicating a direct role of miR-203-mediated regulation of USP26 in metastatic progression of EC.

Conclusions

Cumulatively, these results establish an important mechanism by which decrease in miR-203 expression potentiates metastatic progression in EC via USP26-mediated stabilization of Snail1. Hence, miR-203 can serve as a biomarker of metastasis in EC and is a potential target for therapeutic intervention in EC.

LINC02476 Promotes the Malignant Phenotype of Hepatocellular Carcinoma by Sponging miR-497 and Increasing HMGA2 Expression

Background

Long noncoding RNAs (lncRNAs) can promote hepatocellular carcinoma (HCC) initiation and progression. In this report, we examined the role of lncRNA LINC02476 in HCC.

Methods

The expression levels of different lncRNAs in HCC were explored using the TCGA database and lncRNA LINC02476 was selected for further study. The expression of LINC02476 in HCC tissues was determined by real-time PCR. The clinicopathological characteristics of HCC patients were analyzed relative to the expression of LINC02476. The expression of LINC02476 was downregulated in HCC cells using a lentiviral vector and different assays were performed to study cell growth, proliferation, invasion, apoptosis and the cell cycle. MiR-497 was selected as a miRNA that could interact with LINC02476 which was further tested by RNA immunoprecipitation. HMGA2 was selected as a possible target of miR-497, and their interaction was examined by a luciferase reporter assay.

Results

LINC02476 expression was elevated in HCC cell lines and HCC tissues. When LINC02476 was downregulated, the growth and the invasion of HCC cells decreased in vitro and in vivo. LINC02476 negatively regulated the expression of miR-497 by acting as a ceRNA. HMGA2 was directly targeted and inhibited by miR-497.

Conclusion

The results indicate that LINC02476 functions through the miR-497/HMGA2 axis and that it has a role in the growth and metastasis of HCC cells. Therefore, LINC02476 could be an interesting new molecular target in HCC therapies.

RIOK2 is negatively regulated by miR-4744 and promotes glioma cell migration/invasion through epithelial-mesenchymal transition

RIOK2 is a member of RIO (right open reading frame) kinase family. Recent studies have revealed the involvement of RIO kinases in glioma cell growth and expansion. However, the role and mechanism of RIOK2 in glioma cell migration and invasion remain unclear. Wound healing assay, Transwell assay and real‐time quantitative PCR (qRT‐PCR) detection of matrix metalloproteinases (MMPs) were used to evaluate the migration/invasion of glioma cells. Western blot and qRT‐PCR were employed to measure the expression of epithelial‐mesenchymal transition (EMT) markers. Dual luciferase reporter assay was performed to determine the binding between RIOK2 and miR‐4744. In addition, RIOK2 and miR‐4744 levels were quantified by qRT‐PCR and/or immunohistochemistry in glioma tissues. Transfection of RIOK2 siRNAs significantly inhibited glioma cell migration and invasion and down‐regulated the expression of MMPs (MMP2 and MMP9) and mesenchymal markers (N‐cadherin, β‐catenin, Twist1, fibronectin, ZEB‐1) in glioma cells. Overexpression of RIOK2 showed the opposite effects. MiR‐4744 directly bound to the 3'‐untranslated region of RIOK2 and negatively regulated the expression of RIOK2. Up‐regulation of miR‐4744 inhibited the migration and invasion of glioma cells. Overexpression of RIOK2 could reverse the effects of miR‐4744 up‐regulation on the migration, invasion and EMT process in glioma cells. Moreover, RIOK2 was high, while miR‐4744 was low in glioma tissues, and a negative correlation was found between them. These results suggest that RIOK2 is post‐transcriptionally targeted by miR‐4744, the low miR‐4744 and high RIOK2 levels in glioma may contribute to tumour cell infiltration through promoting the EMT.

Expression of the microRNA-200 Family, microRNA-205, and Markers of Epithelial-Mesenchymal Transition as Predictors for Endoscopic Submucosal Dissection over Esophagectomy in Esophageal Adenocarcinoma: A Single-Center Experience

Endoscopic submucosal dissection (ESD) is an effective treatment of early esophageal adenocarcinomas (EACs). The decision of ESD over esophagectomy is based on clinical evaluation of tumor depth and invasion. On a molecular level, tumor invasion is strongly associated with epithelial-to-mesenchymal transition (EMT). Here, we investigated whether localized ESD-resected and surgically resected EAC samples displayed different expression profiles of EMT protein and microRNA markers and whether these different expression profiles were able to retrospectively discriminate localized and surgically resected samples. By doing this, we aimed to evaluate whether preoperative measurement of EMT marker expression might support the decision regarding ESD over surgery. The results showed that ESD-resected samples displayed an epithelial expression profile, i.e., high expression of epithelial protein markers, whereas surgically resected samples displayed high expression of mesenchymal markers. In addition, the anti-EMT microRNA-205 was significantly more expressed in ESD-resected samples, whereas we found no significant differences in the expression levels of microRNA-200 family members. Furthermore, in our retrospective approach, we have demonstrated that measurement of selected EMT markers and microRNA-205 has significant discrimination power to distinguish ESD-resected and surgically resected samples. We suggest that the assessment of EMT status of EAC samples on a molecular level may support clinical evaluation regarding the applicability of ESD.

Silencing of miR-17-5p suppresses cell proliferation and promotes cell apoptosis by directly targeting PIK3R1 in laryngeal squamous cell carcinoma

Background

Increasing evidence has suggested that microRNAs (miRNAs) act as key post-transcriptional regulators in tumor progression. Previous studies have confirmed that miR-17-5p functions as an oncogene in multiple cancers and contributes to tumor progression. However, the role and biological functions of miR-17-5p in the development of laryngeal squamous cell carcinoma (LSCC) still remain unknown.

Methods

qRT-PCR was used to detect miRNA and mRNA expression levels in LSCC tissues and cell lines. CCK-8 assay was used to measure cell viability and flow cytometry was performed to evaluate cell apoptosis. Western blot analysis was used to detect the protein levels of BAX, BCL-2, cleaved Caspase-3, PIK3R1 and AKT. Luciferase reporter assay was used to detect the effect of miR-17-5p on PIK3R1 expression. Xenograft animal model was used to test the effect of miR-17-5p on LSCC cell in vivo.

Results

In the present study, we found that miR-17-5p expression level was upregulated in LSCC tissues and cell lines. Depletion of miR-17-5p in LSCC cells significantly reduced cell proliferation and promoted cell apoptosis in vitro and in vivo. Mechanically, knockdown of miR-17-5p in LSCC cells inhibited BCL-2 expression while enhanced BAX and cleaved Caspase-3 protein expression. Moreover, depletion of miR-17-5p in LSCC cells suppressed AKT phosphorylation but did not influence PTEN expression. Importantly, miR-17-5p positively regulated PIK3R1 expression by directly binding to its 3′-untranslated region (UTR). Additionally, PIK3R1, which expression was downregulated in LSCC tissues and cell lines, was involved in LSCC cell survival by modulating the activation of AKT signal pathway. Dysregulation of miR-17-5p/PIK3R1 axis was participated in LSCC cell proliferation and apoptosis by inhibiting the activation of the PI3K/AKT signaling pathway.

Conclusions

In conclusion, our study indicates that the miR-17-5p/PIK3R1 axis plays an essential role in the development of LSCC and provides a potential therapeutic target for LSCC treatment.

Reduced miR-203 predicts metastasis and poor survival in esophageal carcinoma

We analyzed data from two non-coding RNA profiling arrays made available by the Gene Expression Omnibus (GEO) and found 17 miRNAs with remarkable differential expression between malignant and normal esophageal tissue. Correlation analysis between expression of these 17 miRNAs and patients’ clinicopathological characteristics showed that miR-203 was down-regulated in esophageal carcinoma (EC) tissues and was significantly associated with lymph node metastasis and poor overall survival. Overexpression of miR-203 significantly attenuated cellular proliferation, migration and invasion by EC cells in culture. Additionally, gene expression profiles and bioinformatics analysis revealed KIF5C to be a direct target of miR-203, and KIF5C overexpression partially counteracted the tumor inhibitory effects of miR-203 on EC cells. We also observed that miR-203, reduced KIFC5 protein levels, promoted cytoplasmic accumulation of Axin2, and reversed the invasive phenotype of EC cells. Taken together, these data demonstrate that miR-203 is a tumor suppressor in EC cells and its expression level could potentially be used as a prognostic indicator for EC patient outcomes.

Exosomes from Adipose-Derived Stem Cells (ADSCs) Overexpressing miR-21 Promote Vascularization of Endothelial Cells

In the past few years, exosomes released from adipose-derived stem cells (abbreviated as ADSCs) have shown promises to provide therapeutic benefits in the fields of regenerative medicine. miRNAs, existing in exosomes, are endogenous, small noncoding RNAs that play important roles in a variety of cellular functions and tumor development. Emerging evidences have indicated that miR-21 is one of the important miRNAs associated with tumor angiogenesis. In this study, we identified the role of exosomes from ADSCs overexpressing miR-21 in regulating/promoting vascularization of endothelial cells. Experimental data indicated an elevated miR-21 level in exosomes released by ADSCs overexpressing miR-21. In vitro matrigel angiogenesis assay showed that exosomes secreted by ADSCs overexpressing miR-21 significantly promoted the vascularization of HUVEC cells (an endothelial cell line). Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot (WB) revealed an upregulation of HIF-1α, VEGF, SDF-1, p-Akt, p-ERK1/2 and downregulation of PTEN in response to miR-21 overexpression, indicating that miR-21 enriched exosomes induced angiogenesis through Akt and ERK activation and also HIF-1α and SDF-1 expression. Our work suggests that exosomes from ADSCs that overexpressing miR-21 can potentially promote vascularization and therefore the transplantation of exosomes from their culture may be suitable for clinical effort in regenerative medicine.

The role of miR-382-5p in glioma cell proliferation, migration and invasion

Background: Dysregulation of a single miRNA can play an essential role in tumor development and progression. Recent studies have shown that miR-382-5p can function as an oncogene or as a tumor suppressor in different types of cancers. However, the role of miR-382-5p in glioma growth and expansion has not been characterized.

Methods: Quantitative real time-PCR (qRT-PCR) was used to measure miR-382-5p levels in glioma tissues. The miR-382-5p mimics and inhibitors were employed to upregulate and downregulate miR-382-5p expression respectively in glioma cells. EdU assay was used to assess cell proliferation. Wound healing and Transwell assays were employed to evaluate cell migration and invasion. Western blot was used to measure the changes of epithelial-to-mesenchymal transition (EMT) markers and the potential miR-382-5p target genes.

Results: We found that miR-382-5p levels were low in glioma tissues as determined by qRT-PCR. EdU assay showed that upregulation of miR-382-5p significantly decreased cell proliferation in both U87 and U251 cells. Wound healing rate was significantly decreased in response to miR-382-5p mimics and significantly increased in response to miR-382-5p inhibitors. Transwell migration assays further confirmed the inhibitory effects of miR-382-5p on the migration in both U251 and U87 cells. Transwell invasion assays showed that upregulation of miR-382-5p resulted in a remarkable decrease in the number of invading cells, whereas downregulation of miR-382-5p led to a significant increase in the numbers of invading U87 and U251 cells. In addition, overexpression of miR-382-5p decreased the protein levels of N-cadherin, Snail and Slug, and increased E-cadherin levels, in glioma cells. Furthermore, miR-382-5p levels negatively correlated with Y box-binding protein 1 (YBX1) in lower grade glioma tissues, and negatively regulated the expression of YBX1 in glioma cells.

Conclusion: In summary, miR-382-5p inhibited proliferation, migration, invasion, and the EMT in glioma cells, possibly through targeting the oncogene YBX1.

Identification of reciprocal microRNA-mRNA pairs associated with metastatic potential disparities in human prostate cancer cells and signaling pathway analysis

The major cause of mortality for prostate cancer (PCa) is metastasis; however, the metastatic mechanism remains unclear. MicroRNAs (miRNAs) alter the expression patterns of essential genes through posttranscriptional regulation during cancer development. The study was mainly aimed at identifying specific miRNA-messenger RNA (mRNA) interactions and signaling pathways associated with PCa distant metastasis. New analytical approaches were applied, combining miRNA and gene expression microarray, to screen differentially expressed miRNA-mRNA pairs in the normal prostate epithelial cell line RWPE-1, the highly-metastatic human PCa cell line PC-3M-1E8 (H-1E8 or 1E8) and the lowly metastatic cell line PC-3M-2B4 (L-2B4 or 2B4). Eight differentially expressed candidate miRNAs and their targets closely related to PCa metastasis were identified and validated in patients by using the Gene Expression Omnibus database. Among them, overexpression of hsa-miR-92b-3p and hsa-let-7a-5p and underexpression of their targets, such as glutathione-S-transferase M3 (GSTM3), baculoviral IAP repeat-containing 3, and cyclin-dependent kinase inhibitor 1 (CDKN1A), were also validated in H-1E8 cells compared with L-2B4 cells. Bioinformatics suggested that hsa-miR-92b-3p and hsa-let-7a-5p and their targets might promote PCa metastasis through platinum-based drug resistance and the JAK-STAT signaling pathway. H-1E8 and L-2B4 cells treated by cisplatin showed the greatly decreased levels of hsa-miR-92b-3p and hsa-let-7a-5p; however, in contrast to 2B4 cells, 1E8 cells did not negatively regulate the increase in the expression levels of the targets GSTM3 and CDKN1A. This finding suggests that the dysregulation between hsa-let-7a-5p/CDKN1A and hsa-miR-92b-3p/GSTM3 pairs is associated with platinum-based chemoresistance of metastatic cancer cells.

miR-143 inhibits migration and invasion through regulating LASP1 in human esophageal cancer

BACKGROUND

Esophageal cancer (EC) is one of the common cancers in China with high incidence and poor prognosis. Increasing evidence has emphasized the important roles of differentially expressed miRNAs in esophageal squamous cell carcinoma (ESCC) progression. Previous studies indicated that miR-143-3p and LASP1 influence cell growth in ESCC and other cancer types. However, the function and molecular mechanism of action of miR-143 and LASP1 in ESCC have not been fully explored.

METHODS

miR-143 and LASP1 expression were detected by quantitative real-time PCR. The protein level of LASP1 was measured by western blot. Cell proliferation was evaluated by MTT assay. Cell migration and invasion capacity was measured by transwell assay. Targeting of LASP1 mRNA by miR-143 was verified by luciferase reporter assay. Overall survival of ESCC patients with different miR-143 expression level was evaluated by Kaplan-Meier survival analysis.

RESULTS

miR-143 expression was down-regulated, while LASP1 expression was up-regulated in ESCC tissues and cells compared to non-malignant counterparts. LASP1 mRNA was identified as a target of miR-143. Low miR-143 expression or high LASP1 expression significantly associated with ESCC patients' decreased survival. miR-143 mimic transfection inhibited ESCC cell proliferation, migration and invasion in vitro, which was impaired by LASP1 overexpression.

CONCLUSION

miR-143 suppressed cell proliferation, migration, and invasion by down-regulating LASP1.

Robust analysis of novel mRNA-lncRNA cross talk based on ceRNA hypothesis uncovers carcinogenic mechanism and promotes diagnostic accuracy in esophageal cancer

Background

ceRNAs have emerged as pivotal players in the regulation of gene expression and play a crucial role in the physiology and development of various cancers. Nevertheless, the function and underlying mechanisms of ceRNAs in esophageal cancer (EC) are still largely unknown.

Methods

In this study, profiles of DEmRNAs, DElncRNAs, and DEmiRNAs between normal and EC tumor tissue samples were obtained from the Cancer Genome Atlas database using the DESeq package in R by setting the adjusted P<0.05 and |log₂(fold change)|>2 as the cutoff. The ceRNA network (ceRNet) was initially constructed to reveal the interaction of these ceRNAs during carcinogenesis based on the bioinformatics of miRcode, miRDB, miRTarBase, and TargetScan. Then, independent microarray data of GSE6188, GSE89102, and GSE92396 and correlation analysis were used to validate molecular biomarkers in the initial ceRNet. Finally, a least absolute shrinkage and selection operator logistic regression model was built using an oncogenic ceRNet to diagnose EC more accurately.

Results

We successfully constructed an oncogenic ceRNet of EC, crosstalk of hsa-miR372-centered CADM2-ADAMTS9-AS2 and hsa-miR145-centered SERPINE1-PVT1. In addition, the risk-score model -0.0053*log₂(CADM2)+0.0168*log₂(SERPINE1)-0.0073*log₂(ADAMTS9-AS2)+0.0905*log₂(PVT1)+0.0047*log₂(hsa-miR372)-0.0193*log₂(hsa-miR145), (log₂[gene count]) could improve diagnosis of EC with an AUC of 0.988.

Conclusion

We identified two novel pairs of ceRNAs in EC and its role of diagnosis. The pairs of hsa-miR372-centered CADM2-ADAMTS9-AS2 and hsa-miR145-centered SERPINE1-PVT1 were likely potential carcinogenic mechanisms of EC, and their joint detection could improve diagnostic accuracy.

Hsa-let-7g promotes osteosarcoma by reducing HOXB1 to activate NF-kB pathway

MicroRNA (miRNA) is known to be involved in regulating the proliferation, migration and apoptosis of cancer cells in osteosarcoma. In this study, We aim to explore the expression of hsa-let-7 g and its role in pathogenesis of osteosarcoma. By analyzing clinical data. We found high expression of hsa-let-7 g in patients with osteosarcoma. The patients with higher expression of hsa-let-7 g showed poorer prognosis and lower survival rate. After downregulation of hsa-let-7 g in cell model and animal model, we found that with downregulation of hsa-let-7 g, the proliferation of osteosarcoma cells was significantly reduced, the level of migration and invasion was down-regulated, the cell cycle was inhibited, and cell apoptosis was increased. Through Dual Luciferase Reporter, immunohistochemistry, western blot and other experiments, it was found that hsa-let-7 g down-regulated HOXB1 gene and activated NF-kB pathway to promote the development of osteosarcoma. In conclusion, hsa-let-7 g is highly expressed in osteosarcoma tissues, and high expression of hsa-let-7 g can promote the occurrence of osteosarcoma by down-regulating HOXB1 and activating NF-kB pathway.

miR-34a inhibits esophageal squamous cell carcinoma progression via regulation of FOXM1

Downregulation of microRNA-34a (miR-34a) has frequently been observed in esophageal squamous cell carcinoma (ESCC). However, the underlying role and molecular mechanism of miR-34a in ESCC remains largely unknown. In the current study, it was demonstrated that miR-34a was downregulated and forkhead box M1 (FOXM1), a target gene of miR-34a, was upregulated in ESCC tumor tissues. Overexpression of miR-34a decreased FOXM1 mRNA and protein expression in the ESCC cell lines tested (TE-1 and TE-8). Inhibition of miR-34a increased FOXM1 mRNA and protein levels in human esophageal epithelial cells (HEEC). In addition, miR-34a mimics reduced the relative luciferase activity of ESCC cells transfected with FOXM1 3'UTR-WT, but not FOXM1 3'UTR-Mut. The CCK8 assay and scratch wound healing assay showed that overexpression of miR-34a induced inhibition of cell proliferation and cell migration. Additionally, transfection with miR-34a mimics reduced the expression of key genes involved in cell migration (MMP2 and MMP9) in ESCC cells. Thus, the present data demonstrated that miR-34a suppressed ESCC progression by directly targeting FOXM1.

miR-590-3p is a novel microRNA which suppresses osteosarcoma progression by targeting SOX9

Osteosarcoma is the most common primary bone malignancy and arises primarily in the metaphyseal ends of long bones in children and adolescents. m iR-590 has been found to have anti-tumor effects in many other cancers. However, the role of miR-590-3p in osteosarcoma is poorly understood. In this study, we show that miR-590-3p was significantly decreased both in osteosarcoma tissues and cell lines, suggesting a potential role of miR-590-3p in osteosarcoma. Over-expression of miR-590-3p inhibited U2OS cell viability as shown by the CCK-8 assay and clonogenic assay. Ki-67 immunofluorescence staining and cell cycle analysis revealed that up-regulation of miR-590-3p inhibited U2OS cell proliferation. Transfection with miR-590-3p mimics suppressed PCNA, Cyclin D1 and CDK4 expression and increased p53 and p21 expression. In addition, U2OS cells transfected with miR-590-3p mimics exhibited reduced cell invasion and migration, characterized by the wound healing assay and transwell assay. Furthermore, bioinformatics analysis demonstrated that SOX9 was a potential target of miR-590-3p. SOX9 was up-regulated in osteosarcoma tissues. Transfection with miR-590-3p mimics markedly suppressed SOX9 expression both at the mRNA level and protein level. Dual luciferase assay validated the direct binding site of miR-590-3p on SOX9. Exogenous SOX9 expression in U2OS cells at least partially reversed the effects of miR-590-3p in U2OS cells. Enforced SOX9 expression restored cell viability in osteosarcoma cells transfected with miR-590-3p mimics. In addition, over-expression of SOX9 restored decreased cell metastasis properties caused by transfection with miR-590-3p mimics in osteosarcoma cells. In summary, these results indicated that miR-590-3p is an anti-cancer miRNA that can inhibit proliferation and metastasis in osteosarcoma cells. Our findings provide a novel insight into the biological function of miR-590-3p in osteosarcoma and SOX9 may be a potential therapeutic target for osteosarcoma.

MicroRNA-381 reduces inflammation and infiltration of macrophages in polymyositis via downregulating HMGB1

The downregulation of microRNA (miR)-381 has been detected in various diseases. The present study aimed to investigate the effects, and underlying mechanisms of miR-381 on inflammation and macrophage infiltration in polymyositis (PM). A mouse model of experimental autoimmune myositis (EAM) was generated in this study. Hematoxylin and eosin staining was conducted to detect the inflammation of muscle tissues. In addition, ELISA and immunohistochemistry were performed to determine the expression levels of associated factors, and reverse transcription-quantitative polymerase chain reaction and western blotting were used to detect the expression levels of related mRNAs and proteins. A luciferase activity assay was used to confirm the binding of miR-381 and high mobility group box 1 (HMGB1) 3' untranslated region. Transwell assays were also performed to assess the migratory ability of macrophages. The results demonstrated that serum creatine kinase (s-CK), HMGB1 and cluster of differentiation (CD)163 expression in patients with PM were increased compared within healthy controls. Conversely, the expression levels of miR-381 were downregulated in patients with PM. Furthermore, high HMGB1 expression was associated with poor survival rate in patients with PM. In the mouse studies, muscle inflammation and CD163 expression were decreased in the anti-IL-17 and anti-HMGB1 groups, compared with in the EAM model group. The expression levels of s-CK, HMGB1, IL-17 and intercellular adhesion molecule (ICAM)-1 were also downregulated in response to anti-IL-17 and anti-HMGB1. These findings indicated that HMGB1 was closely associated with inflammatory responses. In addition, the present study indicated that transfection of macrophages with miR-381 mimics reduced the migration of inflammatory macrophages, and the expression levels of HMGB1, IL-17 and ICAM-1. Conversely, miR-381 inhibition exerted the opposite effects. The effects of miR-381 inhibitors were reversed by HMGB1 small interfering RNA. In conclusion, miR-381 may reduce inflammation and the infiltration of macrophages; these effects were closely associated with the downregulation of HMGB1.

ABC Transporters and Their Role in the Neoadjuvant Treatment of Esophageal Cancer

The prognosis of esophageal cancer (EC) is poor, despite considerable effort of both experimental scientists and clinicians. The tri-modality treatment consisting of neoadjuvant chemoradiation followed by surgery has remained the gold standard over decades, unfortunately, without significant progress in recent years. Suitable prognostic factors indicating which patients will benefit from this tri-modality treatment are missing. Some patients rapidly progress on the neoadjuvant chemoradiotherapy, which is thus useless and sometimes even harmful. At the same time, other patients achieve complete remission on neoadjuvant chemoradiotherapy and subsequent surgery may increase their risk of morbidity and mortality. The prognosis of patients ranges from excellent to extremely poor. Considering these differences, the role of drug metabolizing enzymes and transporters, among other factors, in the EC response to chemotherapy may be more important compared, for example, with pancreatic cancer where all patients progress on chemotherapy regardless of the treatment or disease stage. This review surveys published literature describing the potential role of ATP-binding cassette transporters, the genetic polymorphisms, epigenetic regulations, and phenotypic changes in the prognosis and therapy of EC. The review provides knowledge base for further research of potential predictive biomarkers that will allow the stratification of patients into defined groups for optimal therapeutic outcome.

MicroRNA-595 sensitizes ovarian cancer cells to cisplatin by targeting ABCB1

Ovarian cancer is among the leading cause of cancer-related deaths in females. In this study, we demonstrated that miR-595 expression was downregulated in the ovarian cancer tissues and cell lines. miR-595 expression was lower in the lymph node metastases tissues than in the primary ovarian cancer tissues and normal tissues. Furthermore, miR-595 overexpression suppressed the ovarian cancer cell proliferation, colony formation and invasion and promoted the sensitivity of ovarian cancer cell to cisplatin. We identified ABCB1 as a direct target gene of miR-595 in the ovarian cancer cell. ABCB1 expression was upregulated in the ovarian cancer tissues and cell lines. Morevoer, the expression level of ABCB1 was inversely correlated with miR-595 in the ovarian cancer tissues. In addition, overexpression of ABCB1 decreased the miR-595-overexpressing HO8910PM and SKOV-3 cell sensitivity to cisplatin. Ectopic expression of ABCB1 promoted the miR-595-overexpressing HO8910PM and SKOV-3 cell proliferation, colony formation and invasion. These data suggested that miR-595 acted a tumor suppressor role in ovarian cancer development and increased the sensitivity of ovarian cancer to cisplatin.

MicroRNA-564 is downregulated in glioblastoma and inhibited proliferation and invasion of glioblastoma cells by targeting TGF-β1

Increasing evidence has indicated that aberrant expression of miRNAs has been shown to be strongly implicated in the initiation and progression of glioblastoma. Here, we identified a novel tumor suppressive miRNA, miR-564, and investigated its role and therapeutic effect for glioblastoma. We showed that miR-564 was down-regulated in human glioblastoma tissues and cell lines. Introduction of miR-564 dramatically inhibited cell growth and invasion in glioblastoma cells. Subsequent experiments revealed that Transforming growth factor-β1 (TGF-β1) was a direct and functional target of miR-564 in glioblastoma cells. Furthermore, overexpression of miR-564 decreased p-SMAD and SMAD4 expression, which are the downstream signaling molecules of TGF-β. Meanwhile, ectopic of miR-564 reduced the messenger RNA (mRNA) and protein expression of epidermal growth factor receptor (EGFR) and MMP9. Furthermore, the upregulation of miR-564 suppressed TGF-β-mediated U87 proliferation and migration. The expression of EGFR and MMP9 was upregulated in glioblastoma tissues compared to their normal tissues. The EGFR and MMP9 expression levels were inverse correlated with the expression of miR-564. miR-564 suppressed the growth of U87-engrafted tumors. These findings reveal that miR-564/TGF-β1 signaling that may be required for glioblastoma development and may consequently serve as a new therapeutic target for the treatment of glioblastoma.

Emerging therapeutic targets in esophageal adenocarcinoma

The incidence of gastro-esophageal disease and associated rate of esophageal adenocarcinoma (EAC) is rising at an exponential rate in the United States. However, research targeting EAC is lagging behind, and much research is needed in the field to identify ways to diagnose EAC early as well as to improve the rate of pathologic complete response (pCR) to systemic therapies. Esophagectomy with subsequent reconstruction is known to be a morbid procedure that significantly impacts a patient's quality of life. If indeed the pCR rate of patients can be improved and those patients destined to be pCR can be identified ahead of time, they may be able to avoid this life-altering procedure. While cancer-specific biological pathways have been thoroughly investigated in other solid malignancies, much remains unexplored in EAC. In this review, we will highlight some of the latest research in the field in regards with EAC, along with new therapeutic targets that are currently being explored. After reviewing conventional treatment and current changes in medical therapy for EAC, we will focus on unchartered grounds such as cancer stem cells, genetics and epigenetics, immunotherapy, and chemoradio-resistant pathways as we simultaneously propose some investigational possibilities that could be applicable to EAC.

MicroRNA-300 inhibited glioblastoma progression through ROCK1

Glioblastoma is a common type of brain aggressive tumors and has a poor prognosis. MicroRNAs (miRNAs) are a class of small, endogenous and non-coding RNAs that play crucial roles in cell proliferation, survival and invasion. Deregulated expression of miR-300 has been studied in a lot of cancers. However, the role of miR-300 in glioblastoma is still unknown. In this study, we demonstrated that miR-300 expression was downregulated in glioblastoma tissues compared with the normal tissues. Lower expression level of miR-300 was observed in thirty cases (75 %, 30/40) of glioblastoma samples compared with the normal samples. Moreover, the overall survival of glioblastoma patients with lower miR-300 expression level was shorter than those with higher miR-300 expression level. In addition, miR-300 expression was also downregulated in glioblastoma cell lines. Overexpression of miR-300 inhibited cell proliferation, cell cycle and invasion in glioblastoma cell line U87 and U251. Moreover, we identified ROCK1 as a direct target of miR-300 in U87 and U251 cells. Overexpression of ROCK1 partially rescued the miR-300-mediated cell growth. ROCK1 expression levels in glioblastoma tissues were higher than that in normal tissues. ROCK1 expression levels were higher in thirty-one cases of glioblastoma samples than their normal samples. Furthermore, the expression level ROCK1 was inversely correlated with the expression level of miR-300. Importantly, overexpression of miR-300 suppressed glioblastoma progression in an established xenograft model. In conclusion, we revealed that miR-300 might act as a tumor suppressor gene through inhibiting ROCK1 in glioblastoma.

Overexpression of miR‑21 promotes neural stem cell proliferation and neural differentiation via the Wnt/β‑catenin signaling pathway in vitro

The primary aim of the present study was to examine the effects of microRNA‑21 (miR‑21) on the proliferation and differentiation of rat primary neural stem cells (NSCs) in vitro. miR‑21 was overexpressed in NSCs by transfection with a miR‑21 mimic. The effects of miR‑21 overexpression on NSC proliferation were revealed by Cell Counting kit 8 and 5‑ethynyl‑2'‑deoxyuridine incorporation assay, and miR‑21 overexpression was revealed to increase NSC proliferation. miR‑21 overexpression was confirmed using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). mRNA and protein expression levels of key molecules (β‑catenin, cyclin D1, p21 and miR‑21) in the Wnt/β‑catenin signaling pathway were studied by RT‑qPCR and western blot analysis. RT‑qPCR and western blot analyses revealed that miR‑21 overexpression increased β‑catenin and cyclin D1 expression, and decreased p21 expression. These results suggested that miR‑21‑induced increase in proliferation was mediated by activation of the Wnt/β‑catenin signaling pathway, since overexpression of miR‑21 increased β‑catenin and cyclin D1 expression and reduced p21 expression. Furthermore, inhibition of the Wnt/β‑catenin pathway with FH535 attenuated the influence of miR‑21 overexpression on NSC proliferation, indicating that the factors activated by miR‑21 overexpression were inhibited by FH535 treatment. Furthermore, overexpression of miR‑21 enhanced the differentiation of NSCs into neurons and inhibited their differentiation into astrocytes. The present study indicated that in primary rat NSCs, overexpression of miR‑21 may promote proliferation and differentiation into neurons via the Wnt/β‑catenin signaling pathway in vitro.

MiR-206 inhibits Head and neck squamous cell carcinoma cell progression by targeting HDAC6 via PTEN/AKT/mTOR pathway

As a kind of endogenous noncoding small RNA, microRNA (miRNA) plays important roles of regulation to various physiological functions, while its affections on senescence of human Head and neck squamous cell carcinoma (HNSCC) are still unknown. The objective of this study was to investigate the effect of miR-206 in HNSCC tissues, adjacent normal tissues and cell lines, and explore its biological functions in HNSCC. In our study, the level of miR-206 in HNSCC tissues and adjacent normal tissues was detected via real-time qPCR. The effect of miR-206 on cell proliferation was tested by MTT assay, colony formation and cell cycle assays. In order to explore the effect of miR-206 on HNSCC cell migration and invasion, we performed wound healing assays and transwell assays. Luciferase reporter assays were designed to identify the interaction between 3'UTR of HDAC6 and miR-206. The level of signaling pathway-related proteins was determined by western blot. The expression of miR-206 was found to be observably decreased in HNSCC tissues and cell lines through real time-PCR. Restoration of miR-206 weaked cell proliferation, invasion and migration in HNSCC cells and the cell cycle was arrest in S phase. Further explores have shown that miR-206 could inhibit HNSCC cells proliferation by targeting the HDAC6 via PTEN/AKT/mTOR pathway. Taken together, our results demonstrated that miR-206 plays a critical role in HNSCC progression by targeting HDAC6 via PTEN/AKT/mTOR pathway, which might be a potential target for diagnostic and therapeutic in HNSCC.

MicroRNA-320 inhibits cell proliferation and invasion in breast cancer cells by targeting SOX4

Dysregulation of microRNAs (miRs) can contribute to cancer development and progression. In the present study, the function and underlying molecular mechanisms of miR-320 in breast cancer tumorigenesis and progression were investigated. The results of a reverse transcription-quantitative polymerase chain reaction analysis demonstrated that miR-320 was frequently downregulated in breast cancer tissues compared with adjacent normal tissues. In addition, knockdown of miR-320 in breast cancer cell lines promoted cell proliferation and invasion in vitro, whereas miR-320 overexpression had the opposite effect. Furthermore, a Dual-Luciferase reporter assay indicated that SRY-box 4 (SOX4) is a direct target of miR-320, and the restoration of SOX4 in miR-320-overexpressing cells attenuated the tumor-suppressive effects of miR-320. Collectively, these results indicated that miR-320 acts as a tumor suppressor in breast cancer tumorigenesis and progression.

MicroRNAs: new players in cataract

Cataract is the most common cause of blindness worldwide. Multiple factors such as aging, eye injury, diabetes mellitus, ultraviolet exposure, drug use and other ocular diseases are etiologically linked to cataractogenesis. Due to a rapid increase in aging population, age-related cataract has become the leading cause of blindness. Therefore, it is urgent to understand the molecular mechanism underlying cataractogenesis. MicroRNAs (miRNAs) are a group of endogenous, small noncoding RNAs that regulate gene expression at the post-translational level through binding with the 3'-untranslated regions of target mRNAs. Studies have shown that miRNAs play important roles in multiple cellular functions, including apoptosis, cell proliferation, senescence and stress response. Deregulated expression of miRNAs is also linked to the pathogenesis of many diseases, including ocular diseases. In our review, we focus on miRNAs that are involved in cataract development and discuss their potential applications as novel diagnostic markers and therapeutic targets.

Modulation of chemoresponsiveness to platinum-based agents by microRNAs in cancer

Ovarian cancer accounts for the highest mortality among all gynecologic cancers. Cytoreductive surgery followed by chemotherapy with a platinum-based agent (cisplatin or carboplatin) plus paclitaxel is the first-line option for treatment of epithelial ovarian cancer. However, primary or acquired resistance to platinum-based agents is a major clinical challenge. MicroRNAs are a group of small non-coding RNAs that regulate gene expression post-transcriptionally and may function as oncogenes or tumor-suppressor genes through extensive crosstalk with intracellular signaling pathways. Importantly, their dysregulation has been implicated in ovarian tumorigenesis. Pertinent to chemotherapy, increasing evidence has revealed that miRNAs can be directly linked to chemosensitivity to platinum-based agents in ovarian cancer. In this review, we summarize current evidence concerning the role of miRNAs in prediction and modulation of cellular responses to cisplatin and carboplatin in ovarian cancer.

MicroRNA-130a is upregulated in colorectal cancer and promotes cell growth and motility by directly targeting forkhead box F2

Colorectal cancer (CRC) is one of the most prevalent cancers among males and females worldwide. Despite progress in diagnostic and therapeutic strategies for CRC patients, the prognosis for patients with advanced CRC remains poor. MicroRNAs (miRNAs/miRs) are a class of highly conserved short, endogenously expressed and single‑stranded non‑coding RNAs. In recent years, increasing studies have demonstrated that dysregulation of miRNAs is closely associated with CRC carcinogenesis and progression. The aim of the present study was to explore the expression, roles and underlying molecular mechanism of miR‑130a in CRC. The results indicated that miR‑130a was significantly upregulated in CRC, and that miR‑130a expression levels were correlated with TNM stage and lymph node metastasis of CRC. Inhibition of miR‑130a markedly suppressed colorectal cancer cell proliferation, migration and invasion. Furthermore, forkhead box F2 (FOXF2) was identified as a direct downstream target gene of miR‑130a in colorectal cancer. Downregulation of FOXF2 could partially reverse the functions induced by miR‑130a under‑expression in CRC cells. These findings suggested that miR‑130a can regulate FOXF2 and function as an oncogene in CRC. Therefore, miR‑130a may serve as a useful therapeutic agent for miRNA‑based CRC targeted therapy.

miR-320 inhibited ovarian cancer oncogenicity via targeting TWIST1 expression

Ovarian cancer is the most lethal gynecological cancer in most countries. Increasing studies have demonstrated that dysregulation of microRNAs (miRNAs) can contribute to cancer progression. In this study, we showed that miR-320 was underexpressed in ovarian cancer samples compared to their non-tumor tissues. The expression of Twist homolog 1 (TWIST1) in ovarian cancer tissues was upregulated compared with that in the non-tumorous tissues. We found that the expression of TWIST1 was inversely correlated with that of miR-320 in the ovarian cancer. Overexpression of miR-320 suppressed cell proliferation, cell cycle and invasion in ovarian cancer. We identified TWIST1 as a direct target gene of miR-320 in the ovarian cancer cell. Overexpression of TWIST1 promoted the ovarian cancer cell proliferation, cell cycle and invasion. Ectopic expression of TWIST1 restored the effects of miR-320 on cell proliferation, cell cycle and invasion. These findings revealed that miR-320 was a tumor suppressive gene that supressed cell prloferation, cycle and invasion through targeting TWIST1 in ovarian cancer.

MicroRNA-379 suppresses osteosarcoma progression by targeting PDK1

Osteosarcoma is the most common primary bone tumour. Increasing evidence has demonstrated the pathogenic role of microRNA (miRNAs) dysregulation in tumour development. miR-379 was previously reported to function as an oncogenic or tumour-suppressing miRNA in a tissue-dependent manner. However, its function in osteosarcoma remains unknown. In this study, we found that the expression of miR-379 was downregulated in osteosarcoma tissues and cell lines. Further functional characterization revealed that miR-379 suppressed osteosarcoma cell proliferation and invasion in vitro and retarded the growth of osteosarcoma xenografts in vivo. Mechanistically, PDK1 was identified as the direct target of miR-379 in osteosarcoma, in which PDK1 expression was up-regulated and showed inverse correlation with miR-379. Enforced expression of PDK1 promoted osteosarcoma cell proliferation and rescued the anti-proliferative effect of miR-379. These data suggest that miR-379 could function as a tumour-suppressing miRNA via targeting PDK1 in osteosarcoma.

MicroRNA-147 suppresses human hepatocellular carcinoma proliferation migration and chemosensitivity by inhibiting HOXC6

Patients with hepatocellular carcinoma (HCC) experience poor prognosis and low survival rates. In this study, we explored the molecular mechanism of microRNA-147 (miR-147) in regulating human HCC. We firstly used quantitative RT-PCR (qRT-PCR) to compare the expression levels of miR-147 between 7 HCC and two normal liver cell lines, as well as 10 paired primary HCC tissues and their adjacent non-carcinoma tissues. We found miR-147 was down-regulated in both HCC cell lines and primary HCCs tissues. HCC cell lines HepG2 and HuH7 were transfected with lentiviral vector of miR-147 mimics. We found overexpressing miR-147 significantly inhibited HCC in vitro proliferation and migration, increased 5-FU chemosensitivity, and reduced in vivo tumorigenicity. Luciferase, qRT-PCR and western blot assays showed that HOXC6 was the downstream target of miR-147, and both gene and protein levels of HOXC6 were down-regulated by miR-147 in HCC cells. SiRNA mediated HOXC6 knockdown inhibited in vitro proliferation and migration, and increased 5-FU chemosensitivity in HCC. On the other hand, HOXC6 overexpression reversed the inhibitory effect of miR-147 on HCC in vitro proliferation. Therefore, our results suggest that miR-147 can modulates HCC development through the regulation on HOXC6.

MicroRNA-665 suppressed the invasion and metastasis of osteosarcoma by directly inhibiting RAB23

MicroRNAs (miRNAs) are small, short and noncoding RNAs that regulate gene expression posttranscriptionally. Increasing evidences have demonstrated that deregulated expression of miRNAs is found in osteosarcoma. In this study, we demonstrated that miR-665 was downregulated in osteosarcoma tissues compared to non-tumorous tissues. The overall survival (OS) of osteosarcoma patients with low miR-665 expression was lower than that of these patients with high miR-665 expression. Ectopic expression of miR-665 suppressed the osteosarcoma cell proliferation, EMT and invasion. We identified Rab23 as a direct target gene of miR-665. Rab23 was downregulated in osteosarcoma tissues and cell lines. The expression of miR-665 was inversely associated with the expression of Rab23 in the osteosarcoma tissues. These results suggested that miR-665 acted as a tumor suppressor gene in the development of osteosarcoma.

MicroRNA-127 is a tumor suppressor in human esophageal squamous cell carcinoma through the regulation of oncogene FMNL3

In this study, we investigated the expression patterns and functional roles of microRNA 127 (miR-127) and its target gene Formin-Like 3 (FMNL3) in human esophageal squamous cell carcinoma (ESCC). Quantitative RT-PCR (qRT-PCR) was used to compare miR-127 expression between ESCC cell lines and normal esophageal epithelium cell line, as well as paired ESCC tumors and adjacent normal esophageal tissues in 33 patients. We found miR-127 was aberrantly downregulated in both ESCC cell lines and human ESCC tumors. In ESCC cell lines TE-1 and ECA109 cells, lentiviral-induced miR-127 upregulation markedly inhibited cancer proliferation and migration in vitro, and tumorigenicity in vivo. Through dual-luciferase assay and qRT-PCR, FMNL3 was confirmed to be the downstream target gene of miR-127 in ESCC. Finally, FMNL3 was downregulated by siRNA in TE-1 and ECA109 cells. And we discovered that SiRNA-induced FMNL3 downregulation had tumor suppressive effect in ESCC, inhibiting cancer proliferation, migration in vitro, and tumorigenicity in vivo. These results suggest that miR-127 is downregulated and acting as tumor suppressor in ESCC. Inversely, FMNL3, the target gene of miR-127, is upregulated and acting as an oncogene in ESCC.

MiR-300 suppresses laryngeal squamous cell carcinoma proliferation and metastasis by targeting ROS1

Laryngeal squamous cell carcinoma (LSCC) is a common aggressive head and neck cancer with high mortality and incidence. MicroRNAs (miRNAs) are short, non-coding and endogenous RNAs that posttranscriptionally inhibit gene expression. In this study, we showed that miR-300 expression was downregulated in LSCC tissues compared with adjacent no-tumor tissues. MiR-300 overexpression inhibited Hep-2 cell proliferation, as well as the expression of ki-67 and PCNA. Moreover, overexpression of miR-300 repressed the cell invasion in Hep-2 cells. We identified c-ros oncogene 1 receptor tyrosine kinase (ROS1) as a direct target gene of miR-300 in Hep-2 cell. Furthermore, ROS1 expression was upregulated in LSCC tissues compared with adjacent no-tumor tissues. Interesting, there were an inverse correlation between ROS1 and miR-300 expression in the LSCC tissues. Overexpression of ROS1 increased the Hep-2 cells proliferation and invasion. Overexpression of ROS1 abrogated miR-300 induced cell growth and invasion inhibition. Therefore, our data suggested that miR-300 acted as a tumor suppressive gene in LSCC.

miR-143 suppresses the proliferation of NSCLC cells by inhibiting the epidermal growth factor receptor

MicroRNAs (miRs) regulate the proliferation and metastasis of numerous cancer cell types. It was previously reported that miR-143 levels were downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines, and that the migration and invasion of NSCLC cells was inhibited upon suppression of cell proliferation and colony formation by the upregulation of miR-143. Epidermal growth factor receptor (EGFR), which is a vital factor in the promotion of cancer cell proliferation and has been investigated as a potential focus in cancer therapy, has been reported to be a possible target of miR-143. The present study aimed to investigate the role of miR-143 in NSCLC using NSCLC cell lines and primary cells from NSCLC patients. NSCLC cells were co-transfected with EGFR and miR-143, and the mRNA and protein expression of EGFR were analyzed. Furthermore, the activity of the transfected cancer cells with regard to colony formation, migration, invasion and apoptosis were evaluated. The levels of miR-143 were decreased in the NSCLC cell lines and primary cells from patients with NSCLC compared with the controls. Following transfection with miR-143, the ability of NSCLC cells to proliferate, form colonies, migrate and invade was inhibited. Similarly, knockdown of EGFR led to the suppression of NSCLC cell proliferation. The mRNA and protein expression levels of EGFR were significantly reduced following miR-143 overexpression, and the level of miR-143 was inversely correlated with that of EGFR in NSCLC cells. The results of the present study demonstrated that miR-143 was able to suppress NSCLC cell proliferation and invasion by inhibiting the effects of EGFR, suggesting that EGFR may be considered a potential target for NSCLC therapy.

MicroRNA-765 regulates neural stem cell proliferation and differentiation by modulating Hes1 expression

Neural stem cells (NSCs) are multipotent, self-renewing and undifferentiated cells that have the ability to differentiate to both glial and neuronal lineages. miRNAs act a key role in regulating neuronal fate and self-renewal of NSCs. In this study, we found that ectopic expression of miR-765 promoted NSCs proliferation. Moreover, miR-765 overexpression increased the ki-67 and β-tubulin-III expression inNSCs. Overexpression of miR-765 inhibited the expression of GFAP in NSCs. Furthermore, Hes1 was identified as a direct target gene of miR-765 in NSCs. Overexpression of Hes1 decreased miR-765-induced proliferation of NSCs and inhibited NSCs differentiation to neurons in miR-765-treated NSCs. These results demonstrated that miR-765 acted a crucial role in NSCs differentiation and proliferation by inhibiting Hes1 expression.

Differential role of microRNAs in the pathogenesis and treatment of Esophageal cancer

Esophageal cancer (EC) is the most invasive disease associated with inclusive poor prognosis. EC usually is found as either adenocarcinoma (EAC) or squamous cell carcinomas (ESCC). ESCC forms in squamous cells and highly occurs in the upper third of the esophagus. EAC appears in glandular cells and ordinarily develops in the lower one third of the esophagus near the stomach. Barrett's esophagus (BE) is a metaplastic precursor of EAC. There is a persistent need for improving our understanding of the molecular basis of this disease. MicroRNAs (miRNAs) demonstrate an uncovered class of small, non-coding RNAs that can negatively regulate the protein coding gene, and are associated with approximately all known physiological and pathological processes, especially cancer. MiRNAs can affect cancer pathogenesis, playing a crucial role as either oncogenes or tumor suppressors. The recent emergence of observations on the role of miRNAs in cancer and their functions has induced many investigations to examine their relevance to esophageal cancer. In esophageal cancer, miRNA dysregulation plays a crucial role in cancer prognosis and in patients' responsiveness to neo-adjuvant and adjuvant therapies. In this review, the oncogenic, tumor suppressive, and drug resistance related roles of miRNAs, and their involvement in the pathogenesis and treatment of esophageal cancer were summarized.

miR-410-3p suppresses breast cancer progression by targeting Snail

miR-410-3p acts as an oncogene or tumor-suppressor gene in various types of cancer. However, its role in breast cancer remains unknown. In the present study, expression of miR-410-3p in 30 breast cancer and paired adjacent normal tissues was detected by RT-qPCR. The expression of miR-410-3p was downregulated in 76.7% of the breast cancer samples. To further validate the expression of miR-410-3p in breast cancer, we analyzed miR-410-3p expression profiling data set from The Cancer Genome Atlas (TCGA) including 683 breast cancer and 87 normal breast tissues. We observed that the expression of miR-410-3p was downregulated in breast cancer tissues. Next, we investigated the influence of miR-410-3p on cell proliferation by transiently transfecting the miR-410-3p mimic or inhibitor, as well as their corresponding controls in the MDA-MB-231 and MCF7 cell lines. miR-410-3p overexpression reduced cell growth, colony formation and the number of EdU-positive cells in the MDA-MB-231 cells. In contrast, inhibition of miR-410-3p in the MCF7 cells resulted in a higher proliferation rate as assessed by MTT assay, plate colony formation and EdU assays. Furthermore, miR-410-3p inhibited epithelial-mesenchymal transition. In addition, Snail was found to be a direct target of miR-410-3p based on a luciferase assay. Overexpression of Snail was able to rescue the effect of miR-410-3p in breast cancer cells. Moreover, miR‑410-3p was inversely expressed with Snail in breast cancer samples. Our data provide new knowledge regarding the role of miR-410-3p in breast cancer progression.

By downregulating TIAM1 expression, microRNA-329 suppresses gastric cancer invasion and growth

Gastric cancer (GC) is one of the most common malignant tumors worldwide. Emerging evidence has shown that abnormal microRNAs (miRNAs) expression is involved in tumorigenesis. MiR-329 was previously reported to act as a tumor suppressor or oncogene in some types of cancer. However, its function in gastric cancer (GC) is unclear. Here, we found that miR-329 was down-regulated in GC compared with adjacent controls. Enforced expression of miR-329 inhibited proliferation, migration and invasion of gastric cancer cells in vitro. We identified T lymphoma invasion and metastasis 1 (TIAM1) gene as potential target of miR-329. MiR-329 levels inversely correlated with TIAM1 expression in GC. Importantly, TIAM1 rescued the miR-329-mediated inhibition of cell invasion and proliferation. Finally, reintroduction of miR-329 significantly inhibited tumor formation of GC in the xenograft mice. Our findings suggest that miR-329 is a tumor suppressor and potential therapeutic target of GC

MicroRNA-26b regulates cancer proliferation migration and cell cycle transition by suppressing TRAF5 in esophageal squamous cell carcinoma

BACKGROUND

MicroRNAs have been identified to play important role in the development of human esophageal squamous carcinoma (ESCC). In this study, we examined the regulatory effects of microRNA-26b (miR-26b) on ESCC proliferation, cell-cycle transition and migration.

METHODS

Expressions of miR-26a and miR-2bb were analyzed in 8 ESCC cell lines, and 27 human ESCC tissues and paired adjacent non-tumor tissues. MiR-26a and miR-26b were either upregulated or downregulated in ESCC cell lines TE-1 and Kyse140 cells. Their effects on ESCC in vitro growth, cell-cycle transition and migration were analyzed by proliferation assay, cell-cycle assay and invasion assay, respectively. The association of miR-26b and its downstream target gene, tumor necrosis factor receptor-associated factor 5 (TRAF5), was analyzed by luciferase reporter assay and qRT-PCR. TRAF5 was downregulated in TE-1 and Kyse140 cells to analyze its direct effect on miR-26b downregulation induced ESCC inhibition.

RESULTS

MiR-26b expression was aberrantly upregulated in ESCC cell lines and human ESCC tissues, whereas miR-26a expression was unchanged. In TE-1 and Kyse140 cells, miR-26b downregulation had tumor-suppressive effect, whereas miR-26b downregulation or miR-26a upregulation/downregulation had no significant effect, on ESCC proliferation, cell-cycle transition and migration. TRAF5 is confirmed to be the downstream target of miR-26b in ESCC. SiRNA-mediated TRAF5 downregulation inversely regulated the inhibition of miR-26b downregulation on ESCC proliferation, cell-cycle transition and migration.

CONCLUSION

our study demonstrates that miR-26b downregulation, through the inverse regulation on TRAF5, had tumor-suppressive effect on human ESCC.