miR-124 inhibits growth and invasion of gastric cancer by targeting ROCK1

Methylation-Mediated Silencing of miR-124-3 Regulates LRRC1 Expression and Promotes Oral Cancer Progression

Background: Epigenetic alterations, including DNA methylation, play a crucial role in the development of oral squamous cell carcinoma (OSCC) by regulating the expression of tumor suppressor genes and oncogenes. This study investigated the methylation status of miR-124-3 and its role in OSCC progression. Methods: This study applied the Illumina Infinium MethylationEPIC BeadChip assay to profile >850,000 CpG sites in paired OSCC and normal tissues. The methylation data were validated by further analyzing the methylation level of miR-124-3 by using a bisulfite pyrosequencing assay. We investigated whether miR-124-3 acts as a tumor suppressor by establishing miR-124-3-overexpressing OSCC cells and subjecting them to cell proliferation, colony formation, and migration assays. Dual-luciferase reporter assay was used to validate the target genes of miR-124-3 in OSCC cells. Results: The Infinium MethylationEPIC BeadChip and bisulfite pyrosequencing assays consistently identified hypermethylation of miR-124-3 in OSCC tissues relative to normal oral tissues. It was especially notable that miR-124-3 methylation levels were markedly higher in late-stage tumors than in early-stage, and differed significantly between early-stage tumor and normal tissues, indicating that miR-124-3 methylation is an early event in OSCC development. Methylation of miR-124-3 contributes markedly to the downregulation of the gene, leading to the increased expression of its target gene, leucine-rich repeat-containing 1 (LRRC1), which is considered to be positively associated with cancer progression. Moreover, overexpression of miR-124-3 suppressed the proliferation and migration of OSCC cells, while silencing the expression of LRRC1 produced similar tumor-suppressive effects. Luciferase reporter assays confirmed that miR-124-3 directly targets the 3' untranslated region of LRRC1 to downregulate LRRC1 expression. Conclusions: Hypermethylation-mediated downregulation of miR-124-3 results in increased LRRC1 expression, which drives OSCC progression. These findings highlight DNA methylation of miR-124-3 as a potential biomarker for the early detection of OSCC and a therapeutic target for OSCC treatments.

Tumor Microenvironment Remodeling in Gastrointestinal Cancer: Role of miRNAs as Biomarkers of Tumor Invasion

Gastrointestinal (GI) cancers are the most frequent neoplasm, responsible for half of all cancer-related deaths. Metastasis is the leading cause of death from GI cancer; thus, studying the processes that regulate cancer cell migration is of paramount importance for the development of new therapeutic strategies. In this review, we summarize the mechanisms adopted by cancer cells to promote cell migration and the subsequent metastasis formation by highlighting the key role that tumor microenvironment components play in deregulating cellular pathways involved in these processes. We, therefore, provide an overview of the role of different microRNAs in promoting tumor metastasis and their role as potential biomarkers for the prognosis, monitoring, and diagnosis of GI cancer patients. Finally, we relate the possible use of nutraceuticals as a new strategy for targeting numerous microRNAs and different pathways involved in GI tumor invasiveness.

Tumor-suppressing effects of miR-381-3p in pediatric acute myeloid leukemia via ROCK1 downregulation

MicroRNA (miR)-381-3p is the newly discovered tumor-associated miRNA, which is frequently associated with diverse human malignancies; but, it is still unknown about its effect on acute myeloid leukemia (AML) in children. This work focused on exploring miR-381-3p's effect on childhood AML and identifying the possible mechanisms facilitating new treatment development. Using qRT-PCR analysis, miR-381-3p expression remarkably reduced in pediatric AML patients and AML cell lines (HL-60 and U937). Following transfection of miR-381-3p mimic or inhibitor into HL-60 and U937 cells, we conducted MTT assay to evaluate cell proliferation, flow cytometry (FCM) to measured cell apoptosis and cell cycle, whereas Transwell assays to detect cell invasion and migration. Our results demonstrated that miR-381-3p overexpression remarkably repressed cell growth, invasion and migration; additionally, miR-381-3p overexpression resulted in arrest of cell cycle and enhanced cell apoptosis. In contrast, miR-381-3p knockdown led to an opposite effect. Moreover, we predicted miR-381's target gene and validated it by luciferase reporter assay and TargetScan, separately. We identified miR-381-3p's binding site in ROCK1 3'-UTR. As revealed by Western-blot (WB) assay, miR-381-3p overexpression notably suppressed ROCK1 level. Moreover, restoring ROCK1 expression abolished miR-381-3p's inhibition on cell proliferation, invasion and migration. Data in this work indicated the role of miR-381-3p as the tumor suppressor within pediatric AML by targeting ROCK1. Therefore, miR-381-3p might serve as a potential therapeutic target for the treatment of pediatric AML.

Non-coding RNAs and glioblastoma: Insight into their roles in metastasis

Glioma, also known as glioblastoma multiforme (GBM), is the most prevalent and most lethal primary brain tumor in adults. Gliomas are highly invasive tumors with the highest death rate among all primary brain malignancies. Metastasis occurs as the tumor cells spread from the site of origin to another site in the brain. Metastasis is a multifactorial process, which depends on alterations in metabolism, genetic mutations, and the cancer microenvironment. During recent years, the scientific study of non-coding RNAs (ncRNAs) has led to new insight into the molecular mechanisms involved in glioma. Many studies have reported that ncRNAs play major roles in many biological procedures connected with the development and progression of glioma. Long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are all types of ncRNAs, which are commonly dysregulated in GBM. Dysregulation of ncRNAs can facilitate the invasion and metastasis of glioma. The present review highlights some ncRNAs that have been associated with metastasis in GBM. miRNAs, circRNAs, and lncRNAs are discussed in detail with respect to their relevant signaling pathways involved in metastasis.

Long non-coding RNA NEAT1 increases the aggressiveness of gastric cancer by regulating the microRNA-142-5p/JAG1 axis

Gastric cancer has been indicated to have a high recurrence rate in China. Previous studies have revealed that long non-coding RNA nuclear-enriched abundant transcript 1 (NEAT1) exerted critical roles in cancers. Therefore, the present study aimed to determine the function of NEAT1 and explore the unknown molecular mechanisms of gastric cancer pathogenesis. Reverse transcription-quantitative PCR assay was used to examine the expression of NEAT1, microRNA (miR)-142-5p and jagged1 (JAG1) in gastric cancer. Cell Counting Kit-8 and Transwell assays were conducted to examine cell proliferation, migration and invasion. The protein expression levels of N-cadherin, Vimentin, E-cadherin and JAG1 were quantified by western blot assay. The associations among NEAT1, miR-142-5p and JAG1 were confirmed by dual-luciferase reporter assay and RNA immunoprecipitation. The effects of NEAT1 silencing on tumor growth were evaluated by tumor xenografts. The results indicated that NEAT1 was highly expressed in tumor tissues and cells compared with that in paracancerous tissues and the normal gastric epithelial cell line GES-1 and significantly associated with poor prognosis in gastric cancer. Functional analyses further demonstrated that NEAT1 knockdown suppressed proliferation, motility and tumor growth in vitro and in vivo. Mechanistically, NEAT1 sponged miR-142-5p to regulate JAG1 expression. In addition, the effects of NEAT1 knockdown on the proliferation, migration and invasion of gastric cancer cells could be rescued by miR-142-5p inhibitor, and JAG1 overexpression reversed the miR-142-5p-mediated effects on gastric cancer cells. These findings demonstrated that long non-coding RNA NEAT1 regulated gastric cancer progression by targeting the miR-142-5p/JAG1 axis.

Tumor Suppressive Effects of miR-124 and Its Function in Neuronal Development

MicroRNA-124 (miR-124) is strongly expressed in neurons, and its expression increases as neurons mature. Through DNA methylation in the miR-124 promoter region and adsorption of miR-124 by non-coding RNAs, miR-124 expression is known to be reduced in many cancer cells, especially with high malignancy. Recently, numerous studies have focused on miR-124 due to its promising tumor-suppressive effects; however, the overview of their results is unclear. We surveyed the tumor-suppressive effect of miR-124 in glial cell lineage cancers, which are the most frequently reported cancer types involving miR-124, and in lung, colon, liver, stomach, and breast cancers, which are the top five causes of cancer death. Reportedly, miR-124 not only inhibits proliferation and accelerates apoptosis, but also comprehensively suppresses tumor malignant transformation. Moreover, we found that miR-124 exerts its anti-tumor effects by regulating a wide range of target genes, most notably STAT3 and EZH2. In addition, when compared to the original role of miR-124 in neuronal development, we found that the miR-124 target genes that contribute to neuronal maturation share similarities with genes that cause cancer cell metastasis and epithelial-mesenchymal transition. We believe that the two apparently unrelated fields, cancer and neuronal development, can bring new discoveries to each other through the study of miR-124.

Tumor-Derived Exosomes Enriched by miRNA-124 Promote Anti-tumor Immune Response in CT-26 Tumor-Bearing Mice

Exosomes have been introduced as a new alternative delivery system for the transmission of small molecules. Tumor-derived exosomes (TEXs) not only contain tumor-associated antigens to stimulate antitumor immune responses but also act as natural carriers of microRNAs. The aim of the current study was to evaluate the efficacy of miR-124-3p-enriched TEX (TEXomiR) as cell-free vaccine in the induction of antitumor immune responses in a mouse model of colorectal cancer. Briefly, the exosomes were isolated from cultured CT-26 cell line, and modified calcium chloride method was used to deliver miR-124-3p mimic into the exosomes. We used a CT-26-induced BALB/c mouse model of colorectal cancer and analyzed the effect of TEXomiR on survival, tumor size, spleen and tumor-infiltrated lymphocytes, and splenocyte proliferation. Furthermore, intra-tumor regulatory T cells, cytotoxic activity of the splenocytes, and cytokine secretion was also evaluated to describe the anti-tumor immune response. When the tumor size reached 100 mm³, the mice were injected with TEXomiR, TEX, and/or phosphate-buffered saline (PBS) subcutaneously three times with 3-day interval, and then tumor size was monitored every 2 days. The in vitro results indicated that TEXs could efficiently deliver functional miR-124-3p mimic. The in vivo evaluation in tumor-bearing mice showed that treatment with TEXomiR can elicit a stronger anti-tumor immune response than unloaded TEX and PBS. Significant tumor growth inhibition and increased median survival time was achieved in tumor-bearing mice treated with TEXomiR. A significant decrease in CD4/CD8 and Treg/CD8 ratio in tumor tissue was demonstrated. Moreover, increased cytotoxicity and proliferation of splenocytes in the TEXomiR group compared to the TEX and PBS groups were identified. Taken together, our data demonstrated that tumor-derived exosomes efficiently deliver miR-124-3p mimic, and TEXomiR promotes anti-tumor immune responses.

Long Non-coding RNA MALAT1 Upregulates ZEB2 Expression to Promote Malignant Progression of Glioma by Attenuating miR-124

Long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been shown to play a critical role in the development of several malignancies. However, the potential molecular mechanism of MALAT1 in glioma remains unclear. In the present study, we found that the expression of MALAT1 was aberrantly increased in both human glioma tissues and cells and associated with poor prognosis in glioma patients. We further found that MALAT1 silencing significantly inhibited glioma cell proliferation while induced cell cycle arrest and apoptosis. In parallel, knockdown of MALAT1 decreased tumor volume in vivo. These results suggested that MALAT1 acts as a functional oncogene, resulting in the oncogenicity in glioma. Nevertheless, the tumor-suppressive effect of MALAT1 silencing was reversed by miR-124. Besides, the relevance of ZEB2 in tumor progression has been studied in several forms of human cancer, and ZEB2 was identified as a target of miR-124 and negatively regulated by miR-124. MALAT1 overexpression or miR-124 inhibitor led to increased expression of ZEB2. In summary, our study depicts a novel pathway of MALAT1/miR-124/ZEB2 that regulates the progression of glioma and might provide a promising strategy for glioma therapy.

MicroRNA-124 suppresses the invasion and proliferation of breast cancer cells by targeting TFAP4

MicroRNA (miRNA/miR)-124 is widely accepted as the suppressor of different tumors. The present study aimed to improve understanding of the potential role of miR-124 in breast cancer. The gene expression profile change derived from the overexpression of miR-124 was investigated using RNA sequencing and bioinformatics analysis of the breast cancer cell line SKBR3. The results demonstrated that the gene expression profile of SKBR3 cells significantly changed. In addition, the transcription factor activating enhancer-binding protein 4 (TFAP4) gene was identified among the top 10 differentially expressed genes, and was identified as a novel target gene of miR-124 using a dual-luciferase reporter assay. TFAP4 knockdown in notably impaired SKBR3 cell migration and proliferation, which was consistent with decreasing migration and proliferation ability following overexpression of miR-124. Taken together, these results suggest that overexpression of miR-124 can suppress the migration and proliferation of SKBR3 cells by tarsgeting TFAP4. Thus, TFAP4 may act as a novel therapeutic target of breast cancer.

ONECUT2 Accelerates Tumor Proliferation Through Activating ROCK1 Expression in Gastric Cancer

Background

Transcription factors (TFs) are key regulators which control gene expression during cancer initiation and progression. In the current study, we aimed to explore the proliferative function and clinical significance of TFs in gastric cancer (GC).

Methods

Differential analysis was used to investigate the overall expression difference between normal and tumor tissues of each TF in TCGA-STAD cohort. The quantitative real-time polymerase chain reaction (qRT-PCR) was performed to confirm the mRNA expression of one cut homeobox 2 (ONECUT2) in GC tissues. Western blot analysis was conducted to confirm the protein knockdown efficiency. Cell counting, colony formation, and GC xenograft model assays were performed to confirm the proliferative function of ONECUT2 in GC cells. Gene set enrichment analysis (GESA) and qRT-PCR were conducted to confirm the affected signaling pathways and downstream targets of ONECUT2.

Results

Our data indicated that a TF named ONECUT2 was highly expressed in GC and correlated with patients’ poor prognosis. Importantly, knockdown of ONECUT2 dramatically decreased GC cells proliferation, whereas overexpression of ONECUT2 promoted carcinogenesis in GC. Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed that the upregulating ONECUT2 induced the activation of Wnt signaling pathway and cell cycle regulation pathway. We further identified that ONECUT2 boosted gastric cancer cell proliferation through enhancing ROCK1 (Rho associated coiled-coil containing protein kinase 1) mRNA expression. High level of ROCK1 expression rescued proliferative behavior of ONECUT2-deficient GC cells.

Conclusion

Our findings demonstrated that ONECUT2 promoted GC cells proliferation through activating ROCK1 expression at the DNA level, suggesting that ONECUT2-ROCK1 axis might be a potential therapeutic target in GC.

ARHGEF10L expression regulates cell proliferation and migration in gastric tumorigenesis

We recently reported that Rho guanine nucleotide exchange factor 10-like protein (ARHGEF10L) activated Rho GTPases as guanine nucleotide exchange factor to stimulate liver tumorigenesis. The present study continued to explore the effect of ARHGEF10L on the tumorigenic process of gastric cancer. This study detected increased expression of ARHGEF10L in GC tissues compared to peritumoral tissue samples. SGC7901 cells with ARHGEF10L overexpression showed increased cell proliferation, cell migration, and tube-like structure formation abilities, as well as increased expression of GTP-RhoA, ROCK1, and phospho-Ezrin/Radixin/Moesin. ARHGEF10L overexpression downregulated the expression of E-cadherin and upregulated the expression of N-cadherin and Slug, indicating an activation of EMT in the transfected cells. RNA-sequencing assay detected an increased expression of Heat shock 70 kDa protein 6 in the SGC7901 cells overexpressing ARHGEF10L. The above results suggest that ARHGEF10L expression can stimulate gastric tumorigenesis by prompting RhoA-ROCK1-phospho-ERM signaling, inducing EMT and increasing HSPA6 expression.

The Dual Role of miR-186 in Cancers: Oncomir Battling With Tumor Suppressor miRNA

MicroRNAs (miRNAs) are a class of small non-coding RNAs which regulate gene expression at post-transcriptional level. Alterations of miR-186 expression were demonstrated in numerous cancers, shown to play a vital role in oncogenesis, invasion, metastasis, apoptosis, and drug resistance. MiR-186 was documented as a tumor suppressor miRNA in the majority of studies, while conflicting reports verified miR-186 as an oncomir. The contradictory role in cancers may impede the application of miR-186, as well as other dual-functional miRNAs, as a diagnostic and therapeutic target. This review emphasizes the alterations and functions of miR-186 in cancers and discusses the mechanisms behind the contradictory findings. Among these, target abundance and dose-dependent effects of miR-186 are highlighted. The paper aims to review the challenges involved in developing diagnostic and therapeutic strategies for cancer treatment based on dual-functional miRNAs.

Targeting ROCK signaling in health, malignant and non-malignant diseases

A Rho-associated coiled-coil kinase (ROCK) is identified as a critical downstream effector of GTPase RhoA which contains two isoforms, ROCK1 (also known as p160ROCK and ROKβ) and ROCK2 (also known as Rho-kinase and ROKα), the gene of which is placed on chromosomes 18 (18q11.1) and 2 (2p24), respectively. ROCKs have a principal function in the generation of actin-myosin contractility and regulation of actin cytoskeleton dynamics. They represent a chief role in regulating various cellular functions, such as apoptosis, growth, migration, and metabolism through modulation of cytoskeletal actin synthesis, and cellular contraction through phosphorylation of numerous downstream targets. Emerging evidence has indicated that ROCKs present a significant function in cardiac physiology. Of note, dysregulation of ROCKs involves in several cardiac pathological processes like cardiac hypertrophy, cardiac fibrosis, systemic blood pressure disorder, and pulmonary hypertension. Moreover, ROCKs, in addition to their role in regulating renal arteriolar contraction, glomerular blood flow, and filtration, can also play a role in controlling podocytes, tubular cells, and mesangial cell structure and function. Hyperactivity disorder and over-gene expression of Rho/ROCK have been indicated in different cancers. Furthermore, it seems that increasing the expression of mRNA or ROCK protein has an undesirable effect on patient survival and has a positive impact on the progression and worsening of disease prognosis. This review focuses on the physiological and pathological functions of ROCKs with a particular view on its possible value of ROCK inhibitors as a new therapy in cancers and non-cancer diseases.

MicroRNA-124: An emerging therapeutic target in cancer

MicroRNAs (miRNAs) are noncoding single-stranded RNAs, approximately 20-24 nucleotides in length, known as powerful posttranscriptional regulators. miRNAs play important regulatory roles in cellular processes by changing messenger RNA expression and are widely involved in human diseases, including tumors. It has been reported in the literature that miRNAs have a precise role in cell proliferation, programmed cell death, differentiation, and expression of coding genes. MicroRNA-124 (miR-124) has reduced exparession in various human neoplasms and is believed to be related to the occurrence, development, and prognosis of malignant tumors. In our review, we focus on the specific molecular functions of miR-124 and the downstream gene targets in major cancers, which provide preclinical evidence for the treatment of human cancer. Although some obstacles exist, miR-124 is still attracting intensive research focus as a promising and effective anticancer weapon.

The role of DNMT1/hsa-miR-124-3p/BCAT1 pathway in regulating growth and invasion of esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is the major subtype of esophageal cancer with high aggressiveness and poor prognosis. There is an urgent need for understanding the molecular mechanism underlying the development and progression of ESCC.

Methods

ESCC tissues and corresponding non-neoplastic tissues were collected. The expression and function of miR-124-3p and BCAT1 in two cell lines KYSE-150 and Eca109 were determined.

Results

We show downregulation of miR-124-3p expression in ESCC tissues, which is highly correlated with proliferation and migration of ESCC cell lines KYSE-150 and Eca109. miR-124-3p show high correlation with TNM stage and differentiation grade. Furthermore, miR-124-3p directly targets mRNA 3’UTR region of BCAT1, which results in upregulation of BCAT1 expression as observed in ESCC tissues and cell lines. Also, our data indicates that BCAT1 high expression is strongly linked to the disease-free survival, tumor size, pathologic stage, T classification and differentiation grade. On the other hand, we clarified the upstream mechanism regulating miR-124-3p expression in ESCC, which involves in the hypermethylation-silencing regulation mediated by DNA methyltransferase 1(DNMT1), which is of high expression in ESCC tissues and cell lines in the present study. In addition, DNMT1 knockdown or inhibition of DNMT1 function contributes to downregulation of miR-124-3p and BCAT1 expression.

Conclusions

Our study thus clarifies a new mechanism that DNMT1/miR-124/BCAT1 axis regulates the development and progression of ESCC.

MiRNA-124 inhibits the proliferation, migration and invasion of cancer cell in hepatocellular carcinoma by downregulating lncRNA-UCA1

Purpose: It has been reported that miRNA-124 inhibits hepatocellular carcinoma (HCC) progression, while lncRNA-UCA1 promotes HCC. The aim of this study is to find whether miRNA-124, as a tumor suppressor in HCC can inhibit lncRNA-UCA1 in HCC cell. Methods: Tumor tissues and adjacent healthy tissues were obtained from 66 patients diagnosed with HCC in Binzhou Medical University Hospital from January 2011 to January 2013. Cell proliferation assay, in vitro cell migration and invasion assay were applied for the research. Results: In the present study we found that miRNA-124 was downregulated, while lncRNA-UCA1 was upregulated in tumor tissues comparing to adjacent healthy tissues of HCC patients. Expression of miRNA-124 and lncRNA-UCA1 in tumor tissues were not affected by HBV or HCV infection. Analysis of followed-up data revealed that low miRNA-124 level and high lncRNA-UCA1 level were closely correlated with poor survival. Overexpression of miRNA-124 led to inhibited lncRNA-UCA1 expression in cells of HCC cell lines, while overexpression of lncRNA-UCA1 failed to significantly affect miRNA-124 expression. Expression levels of miRNA-124 and lncRNA-UCA1 were inversely and significantly correlated in tumor tissues but not in adjacent healthy tissues. Overexpression of miRNA-124 led to inhibited, while overexpression of lncRNA-UCA1 led to increased proliferation, migration and invasion rates of HCC cell lines. In addition, lncRNA-UCA1 overexpression attenuated the inhibitory effects of miRNA-124 overexpression on cancer cell proliferation, migration and invasion. Conclusion: Therefore, miRNA-124 may inhibit the proliferation, migration and invasion of cancer cell in hepatocellular carcinoma by downregulating lncRNA-UCA1.

Expression of miR-124 in gastric adenocarcinoma and the effect on proliferation and invasion of gastric adenocarcinoma SCG-7901 cells

Expression of miR-124 in gastric adenocarcinoma cell line SGC-7901 and its effect on biological functions was investigated. Expression of miR-124 in cancer tissues and paracancerous tissues of gastric adenocarcinoma patients was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RT-qPCR was used to detect the expression of miR-124 in human normal gastric epithelial cells GES-1 and gastric adenocarcinoma SGC-7901 cells. Cells in miR-124 group were transfected with miR-124 agomir, cells in NC group were transfected with agomir-negative control sequence and cells in the control group were not transfected. MTT assay was used to detect cell proliferation, and Transwell invasion assay to detect cell invasion ability, and the effect of transfected miR-124 agonist on the proliferation and invasive ability of gastric adenocarcinoma cells was evaluated. RT-qPCR results showed that miR-124 expression was significantly downregulated in gastric adenocarcinoma tumor tissues compared with paracancerous tissues. Compared with cells of normal human gastric epithelial cell line GES-1, the expression of miR-124 human gastric adenocarcinoma SGC-7901 cells was significantly downregulated. At 12 h, there was no significant difference in OD at 490 nm in the three groups (P>0.05). OD (490) in the three groups showed a gradual upward trend. After transfection, proliferation curves of the three groups showed an upward trend, proliferation rate of miR-124 group was significantly lower than that of NC and control groups (P<0.05). The number of invading cells in miR-124 group was significantly lower than that in NC group and control group, but there was no significant difference in the number of cell invasion between the NC and control groups. miR-124 can inhibit the proliferation and invasion of gastric adenocarcinoma cells. Downregulation of miR-124 expression in gastric adenocarcinoma may be closely related to the development of gastric adenocarcinoma.

MicroRNA-217 functions as a tumor suppressor in cervical cancer cells through targeting Rho-associated protein kinase 1

The abnormal expression of microRNAs (miRNAs/miRs) has been widely reported in various tumor types. miR-217 was demonstrated to be aberrantly expressed in a number of tumors, including pancreatic adenocarcinoma and osteosarcoma; however, its specific expression pattern has never been investigated in cervical cancer cells. Compared with normal control, the level of Rho-associated protein kinase 1 (ROCK1) expression was markedly increased in cervical cancer tissues and cells compared with that in non-cancerous tissues and cells. The expression of miR-217 was significantly reduced in cervical cancer tissues and cell lines. Overexpression of miR-217 could suppress colony formation and the cell invasion capacity of SiHa and HeLa cells. Flow cytometry indicated that miR-217 significantly increased cell apoptosis in SiHa and HeLa cells. Dual-luciferase reporter assays demonstrated that ROCK1 was a target gene of miR-217. In addition, overexpression of ROCK1 also led to an increased invasion capacity in SiHa cells, even when miR-217 was inhibited, indicating that the anti-invasive effects of miR-217 were mediated through ROCK1. In summary, the results of the present study indicated that miR-217 functions as a tumor suppressor in cervical cancer cells, primarily by targeting ROCK1.

miR-124 regulates STAT3-mediated cell proliferation, migration and apoptosis in bladder cancer

The etiology and pathogenesis of bladder cancer (BCa) is complex. MicroRNA (miRNA) has been implicated in BCa. Targeting of signal transducer and activator of transcription 3 (STAT3) by miR-124 to regulate tumorigenesis has been demonstrated in other types of cancer. In the present study, miR-124 levels were downregulated in the BCa T24 cell line and STAT3 was increased in BCa cell lines. Transfection of miR-124 mimics into T24 cells significantly inhibited STAT3 expression. A luciferase assay confirmed that miR-124 directly targeted the STAT3 3'untranslated region to inhibit STAT expression. Knockdown of STAT3 expression led to increased apoptosis of T24 cells and reduced tumor growth in vitro. The results demonstrated the molecular mechanisms and biological functions of the miR-124/STAT3 signal pathway at the cellular level and indicate the potential of miR-124 as a therapeutic target for BCa.

miR-124-3p acts as a potential marker and suppresses tumor growth in gastric cancer

miR-124-3p has been implicated in a variety of cancers. The purpose of the present study was to investigate the expression, prognostic roles and functions of miR-124-3p in gastric cancer. Functional studies indicated that ectopic overexpression of miR-124-3p in gastric cancer cells suppressed cell viability and plate colony formation in vitro and tumor growth in vivo. In situ hybridization analysis demonstrated that decreased expression of miR-124-3p was associated with clinical stage and lymph node metastasis, as well as shorter overall survival and disease-free survival rates. Furthermore, it was observed that miR-124-3p repressed the carcinogenesis of gastric cancer by targeting Ras-related C3 botulinum toxin substrate 1 (Rac1) and specificity protein 1 (SP1). Collectively, these results indicate a potential underlying mechanism for the regulation of gastric cancer by miR-124-3p involving targeting of Rac1 and SP1. Thus, miR-124-3p may be an independent indicator of survival and treatment strategy for patients with gastric cancer.

Proposed Molecular and miRNA Classification of Gastric Cancer

Gastric cancer (GC) is a common malignant neoplasm worldwide and one of the main cause of cancer-related deaths. Despite some advances in therapies, long-term survival of patients with advanced disease remains poor. Different types of classification have been used to stratify patients with GC for shaping prognosis and treatment planning. Based on new knowledge of molecular pathways associated with different aspect of GC, new pathogenetic classifications for GC have been and continue to be proposed. These novel classifications create a new paradigm in the definition of cancer biology and allow the identification of relevant GC genomic subsets by using different techniques such as genomic screenings, functional studies and molecular or epigenetic characterization. An improved prognostic classification for GC is essential for the development of a proper therapy for a proper patient population. The aim of this review is to discuss the state-of-the-art on combining histological and molecular classifications of GC to give an overview of the emerging therapeutic possibilities connected to the latest discoveries regarding GC.

Lentivirus-mediated overexpression of miR-124 suppresses growth and invasion by targeting JAG1 and EZH2 in gastric cancer

MicroRNA-124 (miR-124) expression is downregulated and has a tumor suppressor role in various types of cancer. The present study revealed that genes encoding miR-124 were frequently methylated and the expression of miR-124 was downregulated in gastric cancer tissues. Stable expression of miR-124 using a lentiviral vector inhibited gastric cancer cell growth, migration and invasion in vitro. In addition, overexpression of miR-124 suppressed gastric cancer cell xenograft growth in nude mice. The expression of the Notch ligand Jagged1 (JAG1) and enhancer of zeste homolog 2 (EZH2) was downregulated upon miR-124 overexpression, and silencing of JAG1 or EZH2 by RNA interference also suppressed gastric cancer cell growth, migration and invasion. Furthermore, expression of fibronectin and vimentin, not able elements of the epithelial-mesenchymal transition, were suppressed by overexpression of miR-124 or inhibition of JAG1 or EZH2 expressions in GC. Together, these results indicated that miR-124 suppressed gastric cancer progression, partly through inhibiting JAG1 and EZH2. Thus, lentivirus-mediated overexpression of miR-124 may be a potential therapeutic strategy against gastric cancer.

The miR-124-p63 feedback loop modulates colorectal cancer growth

Among the diverse co-regulatory relationships between transcription factors (TFs) and microRNAs (miRNAs), feedback loops have received the most extensive research attention. The co-regulation of TFs and miRNAs plays an important role in colorectal cancer (CRC) growth. Here, we show that miR-124 can regulate two isoforms of p63, TAp63 and ΔNp63, via iASPP, while p63 modulates signal transducers and activators of transcription 1 (STAT1) expression by targeting miR-155. Moreover, STAT1 acts as a regulator of CRC growth by targeting miR-124. Taken together, these results reveal a feedback loop between miRNAs and TFs. This feedback loop comprises miR-124, iASPP, STAT1, miR-155, TAp63 and ΔNp63, which are essential for CRC growth. Moreover, this feedback loop is perturbed in human colon carcinomas, which suggests that the manipulation of this microRNA-TF feedback loop has therapeutic potential for CRC.

Circulating microRNA124-3p, microRNA9-3p and microRNA196b-5p may be potential signatures for differential diagnosis of thyroid nodules

It is important to develop an effective auxiliary approach to distinguish papillary thyroid carcinoma (PTC) from benign nodules because a considerable proportion cannot be identified by fine-needle aspiration cytology at present, resulting in unnecessary thyroidectomy. Circulating miRNAs are potential biomarkers for differential diagnosis of tumors. We aimed to investigate the dysregulation of circulating miRNAs in PTC and evaluate the diagnostic value for differentiation of PTC from benign nodules. We first assessed the expression of miRNAs in patients with PTC, patients with benign nodules and healthy controls using a miRCURY LNA Array (n = 3 for each group). Expression of circulating miR-124-3p, miR-9-3p and miR-5691 was significantly up-regulated, while miR-4701 and miR-196b-5p were down-regulated in PTC patients. The dysregulation of miR-124-3p, miR-9-3p, miR-4701 and miR-196b-5p was further validated by qRT-PCR in fifty participants from each group. The expression of circulating miR-124-3p and miR-9-3p was significantly up-regulated in PTC patients. Both miR-124-3p and miR-9-3p could distinguish PTC from benign nodules with high sensitivity and specificity. There were no significant differences in the expression of circulating miR-4701 and miR-196b-5p between PTC patients and healthy controls. Nevertheless, patients with benign nodules showed a higher level of miR-196b-5p compared with that of PTC patients and healthy controls. ROC analysis indicated that miR-196b-5p had a good diagnostic value for differentiation of benign nodules from PTC. Our study suggested that miR-124-3p, miR-9-3p and miR-196b-5p may be potential signatures for differential diagnosis of thyroid nodules in eastern coastal areas of China.

MicroRNA-216b reduces growth, migration and invasion of pancreatic ductal adenocarcinoma cells by directly targeting ρ-associated coiled-coil containing protein kinase 1

Developments in cancer therapy have greatly improved the survival time for patients with pancreatic ductal adenocarcinoma (PDAC); however, the prognosis of patients with PDAC remains poor. Understanding the expression patterns and functions of microRNAs may provide strategies for the diagnosis and treatment of patients with PDAC. The present study aimed to explore the expression and functions of microRNA-216b (miR-216b) in PDAC. The expression of miR-216b in PDAC tissues and cell lines was quantified with reverse transcription-quantitative polymerase chain reaction. An miR-216b mimic was introduced into PDAC cells to induce the effects of miR-21b overexpression. The effects of miR-216b overexpression on growth, migration and invasion of PDAC cells were evaluated by cell proliferation assay, migration and invasion assays, respectively. The molecular mechanism underlying the suppressive effects of miR-216b on PDAC was also examined; a direct target gene of miR-216b, ρ-associated coiled-coil containing protein kinase 1 (ROCK1), was downregulated by ROCK1 short interfering RNA to investigate the effects on growth, migration and invasion of PDAC cells. The present study revealed that miR-216b was significantly downregulated in PDAC tissues and cell lines. Overexpression of miR-216b inhibited growth, migration and invasion of PDAC cells in vitro. ROCK1 was identified as a direct target gene of miR-216b in pancreatic cancer and the downregulation of ROCK1 resembled the effects of miR-216b overexpression in PDAC cells. Taken together, miR-216b acted as a tumor suppressor in PDAC and may represent a novel therapeutic target in PDAC.

miR-302b inhibits tumorigenesis by targeting EphA2 via Wnt/ β-catenin/EMT signaling cascade in gastric cancer

Background

EphA2 is a crucial oncogene in gastric cancer (GC) development and metastasis, this study aims to identify microRNAs that target it and serve as key regulators of gastric carcinogenesis.

Methods

We identified several potential microRNAs targeting EphA2 by bioinformatics websites and then analyzed the role of miR-302b in modulating EphA2 in vitro and in vivo of GC, and it’s mechanism.

Results

Our analysis identified miR-302b, a novel regulator of EphA2, as one of the most significantly downregulated microRNA (miRNA) in GC tissues. Overexpression of miR-302b impaired GC cell migratory and invasive properties robustly and suppressed cell proliferation by arresting cells at G0–G1 phase in vitro. miR-302b exhibited anti-tumor activity by reversing EphA2 regulation, which relayed a signaling transduction cascade that attenuated the functions of N-cadherin, β-catenin, and Snail (markers of Wnt/β-catenin and epithelial-mesenchymal transition, EMT). This modulation of EphA2 also had distinct effects on cell proliferation and migration in GC in vivo.

Conclusions

miR-302b serves as a critical suppressor of GC cell tumorigenesis and metastasis by targeting the EphA2/Wnt/β-catenin/EMT pathway.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3875-3) contains supplementary material, which is available to authorized users.

In vivo and in vitro effects of microRNA-124 on human gastric cancer by targeting JAG1 through the Notch signaling pathway

In this study, we aim to determine the function of miR-124 on gastric cancer (GC) cells and the underlying mechanism that involves jaddeg1 (JAG1) and the Notch signaling pathway. GC tissues and adjacent tissues from 100 patients suffering from GC were selected. GC SGC-7901 and AGS cells were selected and grouped into control, mimic-NC, miR-124 mimic, inhibitor-NC, miR-124 inhibitor, and miR-124 inhibitor + si-JAG1 groups. RT-qPCR and a Western blotting assay were conducted to detect the expression of miR-124, JAG1, and Notch signaling pathway-related proteins (NICD, HES1, and HES5). MTS, wound-healing, transwell assay and flow cytometry were performed to detect cell proliferation, migration, invasion, cell cycle distribution, and apoptosis, respectively. Compared with adjacent tissues, a lower miR-124 expression and higher JAG1 expression were found in GC tissues. JAG1 is a direct target gene of miR-124. Compared with the control group, the expression of JAG1, NICD, HES1, and HES5, cell invasion, migration, and proliferation in the miR-124 mimic group were decreased, while the apoptosis rate was increased and cells were arrested at the G0/G1 phase. Compared with the miR-124 inhibitor group, the expression of JAG1, NICD, HES1, and HES5, cell invasion, migration, and proliferation in the miR-124 inhibitor + si-JAG1 group were decreased, while the apoptosis rate and cell ratio at the G0/G1 phase were increased. The demonstration that miR-124 inhibits GC cell growth supports the concept that miR-124 functions as a tumor suppressor by a mechanism that involves translational repression of the JAG1 and the inhibition of Notch signaling pathway.

MicroRNA-124 suppresses proliferation and glycolysis in non-small cell lung cancer cells by targeting AKT-GLUT1/HKII

Non-small cell lung cancer accounts for 85% of all types of lung cancer and is the leading cause of worldwide cancer-associated mortalities. MiR-124 is epigenetically silenced in various types of cancer and plays important roles in tumor development and progression. MiR-124 was also significantly downregulated in non-small cell lung cancer patients. Glycolysis has been considered as a feature of cancer cells; hypoxia-inducible factor 1-alpha/beta and Akt are key enzymes in the regulation of glycolysis and energy metabolism in cancer cells. However, the role of miR-124 in non-small cell lung cancer cell proliferation, glycolysis, and energy metabolism remains unknown. In this research, cell proliferation was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; furthermore, glucose consumption and lactic acid production were assessed; adenosine triphosphate content and NAD⁺/NADH were also detected. These tests were conducted using the normal non-small cell lung cancer cell line A549, which was transfected variedly with miR-mimics, miR-124 mimics, miR-124 inhibitor, pc-DNA3.1(+)-AKT1, and pc-DNA3.1(+)-AKT2 plasmid. Here, we show that miR-124 overexpression directly decreased cell growth, glucose consumption, lactate production, and energy metabolism. MiR-124 also negatively regulates glycolysis rate-limiting enzymes, glucose transporter 1 and hexokinase II. Our results also showed that miR-124 negatively regulates AKT1 and AKT2 but no regulatory effect on hypoxia-inducible factor 1-alpha/beta. Overexpression of AKT reverses the inhibitory effect of miR-124 on cell proliferation and glycolytic metabolism in non-small cell lung cancer. AKT inhibition blocks miR-124 silencing-induced AKT1/2, glucose transporter 1, hexokinase II activation, cell proliferation, and glycolytic or energy metabolism changes. In summary, this study demonstrated that miR-124 is able to inhibit proliferation, glycolysis, and energy metabolism, potentially by targeting AKT1/2-glucose transporter 1/hexokinase II in non-small cell lung cancer cells.

Inhibition of the Hedgehog signaling pathway suppresses cell proliferation by regulating the Gli2/miR-124/AURKA axis in human glioma cells

Multiple lines of evidence indicate that aberrant activation of Hedgehog (Hh) signaling plays an important role in tumorigenesis in human glioma. However, the underlying molecular mechanism and crucial downstream targets of glioma-associated oncogene (Gli), a primary transcriptional regulator of Hh signaling, are not fully understood. Here, we report the identification of miR-124 as a novel downstream target of the transcriptional factor Gli2, which is important for proliferation and tumor growth in human glioma cells. Blockade of Hh signaling leads to a remarkable increase in miR-124 expression in glioma cells, whereas overexpression of Gli2 suppresses miR-124 expression by increasing the direct binding of Gli2 to the upstream region of the transcriptional start site for miR-124. Furthermore, we found that miR-124 potentially interacts with the 3'-UTR region of AURKA. Overexpression of miR-124 significantly decreased the expression of AURKA in glioma cells. In contrast, the loss of miR-124 led to the increased expression of AURKA mRNA and protein. In addition, cell proliferation and colony formation ability were significantly decreased following Gli2 knockdown in human glioma cells, while transfection with a miR-124 inhibitor rescued the proliferative ability of cells. These results demonstrate that miR-124 is an important downstream target gene of Hh signaling, and the Gli2/miR-124/AURKA axis is essential for the proliferation and growth of human glioma cells.

Role of miRNAs in human cancer metastasis: Implications for therapeutic intervention

Metastasis is the spread and growth of localized cancer to new locations in the body and is considered the main cause of cancer-related deaths. Metastatic cancer cells display distinct genomic and epigenomic profiles and almost universally an aggressive pathophysiology. A better understanding of the molecular mechanisms and regulation of metastasis, including how metastatic tumors grow and survive in the nascent niche and the interactions of the emergent metastatic cancer cells within the local microenvironment may provide tools to design strategies to restrict metastatic dissemination. Aberrant microRNAs (miRNA) expression has been reported in metastatic cancer cells. MicroRNAs are known to regulate divergent and/or convergent metastatic gene pathways including activation of reprogramming switches during metastasis. An in-depth understanding of role of miRNAs in the metastatic cascade may lead to the identification of novel targets for anti-metastatic therapeutics as well as potential candidate miRNAs for cancer treatment. This review primarily focuses on the role of miRNAs in the mechanisms of cancer metastasis as well as implications for metastatic cancer treatment.

MicroRNA-124 rs531564 Polymorphism and Cancer Risk: A Meta-analysis

Several studies reported there was a polymorphism (rs531564 C > G) in miR-124 gene. To investigate the MiR-124 rs531564 polymorphism and cancer risk. We conducted a literature search of the Medline, Embase and Wangfang Medicine databases to identify all relevant studies for this meta-analysis. We determined that the miR-124 rs531564 polymorphism was significantly associated with decreased risks of cancers in the allelic model (G vs C, OR=0.71, 95% CI=0.53-0.94, P=0.02), homozygote model (GG vs CC, OR=0.42, 95% CI=0.26-0.66, P=0.0002), dominant model (GG/GC vs CC, OR=0.71, 95% CI=0.51-0.98, P=0.04) and recessive model (GG vs GC/CC, OR=0.43, 95% CI=0.27-0.69, P=0.0004). In an analysis stratified by cervical cancer group, significant associations were observed in the allelic model (G vs C, OR=0.46, 95% CI=0.32-0.66, P<0.0001), and dominant model (GG/GC vs CC, OR=0.45, 95% CI=0.3-0.66, P<0.0001). Subgroup analysis also revealed a decreased risk for esophageal squamous cell carcinoma in the homozygote model (GG vs CC, OR=0.45, 95% CI=0.27-0.75, P=0.002) and recessive model (GG vs GC/CC, OR=0.46, 95% CI=0.28-0.75, P=0.002). This meta-analysis suggests that the miR-124 rs531564 C > G polymorphism is an important risk factor for cancers among the Chinese population.

Potential Diagnostic, Prognostic and Therapeutic Targets of MicroRNAs in Human Gastric Cancer

Human gastric cancer (GC) is characterized by a high incidence and mortality rate, largely because it is normally not identified until a relatively advanced stage owing to a lack of early diagnostic biomarkers. Gastroscopy with biopsy is the routine method for screening, and gastrectomy is the major therapeutic strategy for GC. However, in more than 30% of GC surgical patients, cancer has progressed too far for effective medical resection. Thus, useful biomarkers for early screening or detection of GC are essential for improving patients' survival rate. MicroRNAs (miRNAs) play an important role in tumorigenesis. They contribute to gastric carcinogenesis by altering the expression of oncogenes and tumor suppressors. Because of their stability in tissues, serum/plasma and other body fluids, miRNAs have been suggested as novel tumor biomarkers with suitable clinical potential. Recently, aberrantly expressed miRNAs have been identified and tested for clinical application in the management of GC. Aberrant miRNA expression profiles determined with miRNA microarrays, quantitative reverse transcription-polymerase chain reaction and next-generation sequencing approaches could be used to establish sample specificity and to identify tumor type. Here, we provide an up-to-date summary of tissue-based GC-associated miRNAs, describing their involvement and that of their downstream targets in tumorigenic and biological processes. We examine correlations among significant clinical parameters and prognostic indicators, and discuss recurrence monitoring and therapeutic options in GC. We also review plasma/serum-based, GC-associated, circulating miRNAs and their clinical applications, focusing especially on early diagnosis. By providing insights into the mechanisms of miRNA-related tumor progression, this review will hopefully aid in the identification of novel potential therapeutic targets.

NF-κB-mediated miR-124 suppresses metastasis of non-small-cell lung cancer by targeting MYO10

Recently, dysregulation of microRNAs plays a critical role in cancer metastasis. Here, an in vivo selection approach was used to generate highly aggressive NSCLC sub-cell lines followed by comparing the microRNAs expression using microarrays. miR-124 was notably deregulated in both highly invasive sub-cell lines and node-positive NSCLC specimens. Over-expression of miR-124 robustly attenuated migration and metastatic ability of the aggressive cells. MYO10 was subsequently identified as a novel functional downstream target of miR-124, and was up-regulated in node-positive NSCLC tissues. Knockdown of MYO10 inhibited cell migration, whereas forced MYO10 expression markedly rescued miR-124-mediated suppression of cell metastasis. Additionally, we found an activated NF-κB-centered inflammatory loop in the highly aggressive cells leading to down-regulation of miR-124. These results suggest that NF-κB-regulated miR-124 targets MYO10, inhibits cell invasion and metastasis, and is down-regulated in node-positive NSCLC.

Influence of hydrogen sulfide on zymogen activation of homocysteine-induced matrix metalloproteinase-2 in H9C2 cardiocytes

OBJECTIVE

To observe the influence of different concentrations of homocysteine (Hcy) and hydrogen sulfide (H2S) on the secretion and activation of matrix metalloproteinase-2 (MMP-2) in cardiocytes so as to search for new ways to fight against myocardial tissue fibrosis.

METHODS

Cardiocytes H9C2 was cultured in vitro and different concentrations of Hcy and H2S were added for 6-h and 24-h cultivation. MTT cell proliferation assay was applied to test the activation change of cardiocytes H9C2 after affecting by different concentrations of Hcy and H2S. ELISA and MTT were employed to detect the expression and enzymatic activity of MMP-2.

RESULTS

The H9C2 cell inhibition of activity was more significant with 1000 μmol/L of Hcy as compared with other concentrations (P < 0.001). With 2.5-100.0 μmol/L Hcy and 0.1, 1.0 and 10.0 mmol/L H2S, the activity of H9C2 did not change significantly (P > 0.05). Hcy with concentrations of 10, 50 and 100 μmol/L could increase the quantity of MMP-2 secreted by cardiocytes H9C2, and the interaction strength was concentration-dependent (P < 0.05). After interacting with 100 μmol/L of Hcy for 6 h, the zymogen activation effect of MMP-2 was stronger than that of the 2.5-25 μmol/L group (P < 0.05). After interacting with Hcy and H2S (1.0 mmol/L) for 6 h and 24 h, the activation effect of MMP-2 was stronger than those interacted with 10, 25, 50 and 100 μmol/L of Hcy (P < 0.05).

CONCLUSIONS

Hcy can increase the production of MMP-2 secreted by H9C2 cell and improve its zymogen activation. Besides, the interaction strength is concentration-dependent; while H2S can up-regulate the activation of MMP-2 and co-promote the activation of MMP-2 with Hcy as well.

MicroRNA-198 inhibited tumorous behaviors of human osteosarcoma through directly targeting ROCK1

Osteosarcoma is an aggressive primary sarcoma of bone and occurs mainly in adolescents and young adults. The prognosis of OS remains poor, and most of them will die due to local relapse or metastases. The discovery of microRNAs provides a new possibility for the early diagnosis and treatment of OS. Thus, the aim of this study was to explore the expression and functions of microRNA-198 (miR-198) in osteosarcoma. The expression levels of miR-198 were determined by qRT-PCR in osteosarcoma tissues and cell lines. Cell proliferation assays, migration and invasion assays were adopted to investigate the effects of miR-198 on tumorous behaviors of osteosarcoma cells. The results showed that miR-198 expression levels were lower in osteosarcoma tissues and cell lines. In addition, low miR-198 expression levels were correlated with TNM stage and distant metastasis. After miR-198 mimics transfection, cell proliferation, migration and invasion were significantly suppressed in the osteosarcoma cells. Furthermore, ROCK1 was identified as a novel direct target of miR-198 in osteosarcoma. These findings suggested that miR-198 may act not only as a novel prognostic marker, but also as a potential target for molecular therapy of osteosarcoma.

miR-124 interacts with the Notch1 signalling pathway and has therapeutic potential against gastric cancer

Aberrant Notch signalling plays an important role in cancer progression. However, little is known about the interaction between miRNA and the Notch signalling pathway and its role in gastric cancer (GC). In this study, we found that miR-124 was down-regulated in GC compared with adjacent normal tissue. Forced expression of miR-124 inhibited GC cell growth, migration and invasion, and induced cell cycle arrest. miR-124 negatively regulated Notch1 signalling by targeting JAG1. miR-124 levels were also shown to be inversely correlated with JAG1 expression in GC. Furthermore, we found that the overexpression of the intracellular domain of Notch1 repressed miR-124 expression, promoted GC cell growth, migration and invasion. Conversely, blocking Notch1 using a γ-secretase inhibitor up-regulated miR-124 expression, inhibited GC cell growth, migration and invasion. In conclusion, our data demonstrates a regulatory feedback loop between miR-124 and Notch1 signalling in GC cells, suggesting that the miR-124/Notch axis may be a potential therapeutic target against GC.

The feedback loop between miR-124 and TGF-β pathway plays a significant role in non-small cell lung cancer metastasis

Increasing evidence shows that micro RNAs (miRNAs) play a critical role in tumor development. However, the role of miRNAs in non-small cell lung cancer (NSCLC) metastasis remains largely unknown. Here, we found that miR-124 expression was significantly impaired in NSCLC tissues and associated with its metastasis. In vitro and in vivo experiments indicate that restoring miR-124 expression in NSCLC cells had a marked effect on reducing cell migration, invasion and metastasis. Mechanistic analyses show that Smad4, a cobinding protein in transforming growth factor-β (TGF-β) pathway, was identified as a new target gene of miR-124. Restoring Smad4 expression in miR-124-infected cells could partially rescue miR-124-induced abolition of cell migration and invasion. Notably, upon TGF-β stimulation, phosphorylation of Smad2/3 was modulated by alteration of miR-124 or Smad4 expression, followed by inducing some special transcription of downstream genes including Snail, Slug and ZEB2, all of which may trigger epithelial-mesenchymal transition and be associated with NSCLC metastasis. Moreover, activation of TGF-β pathway may enhance expression of DNMT3a, leading to hypermethylation on miR-124 promoter. Therefore, heavily loss of miR-124 expression further enhances Smad4 level by this feedback loop. Taken together, our data show for the first time that the feedback loop between miR-124 and TGF-β pathway may play a significant role in NSCLC metastasis. Targeting the loop may prove beneficial to prevent metastasis and provide a more effective therapeutic strategy for NSCLC.

Novel Insights into the Roles of Rho Kinase in Cancer

Rho-associated coiled-coil kinase (ROCK) is a major downstream effector of the small GTPase RhoA. The ROCK family, consisting of ROCK1 and ROCK2, plays a central role in the organization of the actin cytoskeleton, and is involved in a wide range of fundamental cellular functions such as contraction, adhesion, migration, proliferation, and apoptosis. Since the discovery of effective inhibitors such as fasudil and Y27632, the biological roles of ROCK have been extensively explored in numerous diseases, including cancer. Accumulating evidence supports the concept that ROCK plays important roles in tumor development and progression through regulating many key cellular functions associated with malignancy, including tumorigenicity, tumor growth, metastasis, angiogenesis, tumor cell apoptosis/survival and chemoresistance as well. This review focuses on the new advances of the most recent 5 years from the studies on the roles of ROCK in cancer development and progression; the discussion is mainly focused on the potential value of ROCK inhibitors in cancer therapy.

MicroRNA‑144 inhibits migration and proliferation in rectal cancer by downregulating ROCK‑1

Cancer of the colon and rectum are two distinct entities, which require different treatment strategies and separate treatment. MicroRNAs (miRNAs) act as critical regulators of genes involved in several biological processes. Aberrant alterations of miRNAs have been found in several types of cancer, including colon cancer and rectal cancer. Extensive catalogues of downregulated miRNAs have been identified for colon cancer, whereas only limited data are available for rectal cancer. An example of miRNA profiling in a previous study found that miRNA (miR)‑144 showed aberrant expression and appeared to be rectal cancer‑specific, its expression not being reported in colon cancer. In the present study, the role of miR‑144 in rectal cancer was investigated. SW837 and SW1463 cell lines were selected as rectal cell carcinoma cells. Using reverse transcription-quantitative polymerase chain reaction, western blot, BrdU, cell migration and cell viability assays, it was found that the expression levels of miR‑144 were significantly reduced in the SW837 and SW1463 cell lines, and the overexpression of miR‑144 suppressed rectal cancer cell viability, migration and proliferation. In addition, Rho‑associated coiled‑coil containing protein kinase 1 (ROCK1) was identified as a target of miR‑144 in the rectal cancer cells. The supplementation of ROCK1 markedly restored the cell migration and proliferation, which was inhibited by miR‑144. Together, the data of the present study demonstrated that miR‑144 acts as a tumor suppressor by targeting ROCK1, and indicates the potential of miR‑144 as a novel biomarker and target in the treatment of rectal cancer.

miR-411 regulated ITCH expression and promoted cell proliferation in human hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most common human malignancies and the third most common cause of cancer mortality in the world. In this study, we report that miR-411 expression is markedly upregulated in HCC cells and HCC tissues compared with normal control tissues and cells. Previous studies have shown that miR-411 plays a crucial role in a variety of biological processes in various human cancer cells. However, the specific function of miR-411 in HCC remains unclear. Ectopic expression of miR-411 promoted the proliferation and anchorage-independent growth of HCC cells, whereas inhibition of miR-411 reduced this effect. Bioinformatics analysis further revealed ITCH, a putative tumor suppressor as a potential target of miR-411. Data from luciferase reporter assays showed that miR-411 directly binds to the 3'-untranslated region (3'-UTR) of ITCH mRNA and repressed expression at both transcriptional and translational levels. In functional assays, miR-411 promoted HCC cell proliferation, which could be suppressed by miR-411-in. Taken together, our data provide convincing evidence that miR-411 functions as an onco-miRNA, which was associated with cell proliferation of HCC, and its oncogenic effect is mediated chiefly through direct suppression of ITCH expression.

MicroRNAs May Serve as Emerging Molecular Biomarkers for Diagnosis and Prognostic Assessment or as Targets for Therapy in Gastric Cancer

Gastric cancer (GC) is one of the most common cancers, with high incidences in East Asia countries. Most GC patients have been reported with low early diagnosis rate and show extremely poor prognosis. Therefore, it is necessary to develop novel and more sensitive biomarkers to improve early diagnosis and therapy in order to provide longer survival and better quality of life for gastric cancer patients. MicroRNAs (miRNAs) play crucial roles in GC development and progression. miRNAs have emerged as a novel molecular biomarker for cancer diagnosis, prognosis and therapy with surprising stability in tissues, serum or other body fluids. This review summarizes major advances in our current knowledge about potential miRNA biomarkers for GC that have been reported in the past two years.