MicroRNA-550a acts as a pro-metastatic gene and directly targets cytoplasmic polyadenylation element-binding protein 4 in hepatocellular carcinoma

CPEB2 inhibit cell proliferation through upregulating p21 mRNA stability in glioma

Glioma is the most common primary malignant brain tumor in adults and remains an incurable disease at present. Thus, there is an urgent need for progress in finding novel molecular mechanisms that control the progression of glioma which could be used as therapeutic targets for glioma patients. The RNA binding protein cytoplasmic polyadenylate element-binding protein 2 (CPEB2) is involved in the pathogenesis of several tumors. However, the role of CPEB2 in glioma progression is unknown. In this study, the functional characterization of the role and molecular mechanism of CPEB2 in glioma were examined using a series of biological and cellular approaches in vitro and in vivo. Our work shows CPEB2 is significantly downregulated in various glioma patient cohorts. Functional characterization of CPEB2 by overexpression and knockdown revealed that it inhibits glioma cell proliferation and promotes apoptosis. CPEB2 exerts an anti-tumor effect by increasing p21 mRNA stability and inducing G1 cell cycle arrest in glioma. Overall, this work stands as the first report of CPEB2 downregulation and involvement in glioma pathogenesis, and identifies CPEB2 as an important tumor suppressor gene through targeting p21 in glioma, which revealed that CPEB2 may become a promising predictive biomarker for prognosis in glioma patients.

MiR-550a-3p restores damaged vascular smooth muscle cells by inhibiting thrombomodulin in an <em>in vitro</em> atherosclerosis model

Thrombomodulin (TM) is involved in the pathological process of atherosclerosis; however, the underlying mechanism remains unclear. Oxidised low-density lipoprotein (Ox-LDL; 100 μg/mL) was used to induce human vascular smooth muscle cells (HVSMCs) into a stable atherosclerotic cell model. The expression levels of miR-550a-3p and TM were detected by real-time reverse transcription-polymerase chain reaction. Cell proliferation was estimated using CCK8 and EDU assays. Wound scratch and transwell assays were used to measure the ability of cells to invade and migrate. Propidium iodide fluorescence-activated cell sorting was used to detect apoptosis and cell cycle changes. A dual-luciferase reporter assay was performed to determine the binding of miR-550a-3p to TM. Our results suggested the successful development of a cellular atherosclerosis model. Our data revealed that TM overexpression significantly promoted the proliferation, invasion, migration, and apoptosis of HVSMCs as well as cell cycle changes. Upregulation of miR-550a-3p inhibited the growth and metastasis of HVSMCs. Furthermore, miR-550a-3p was confirmed to be a direct target of TM. Restoration of miR-550a-3p expression rescued the effects of TM overexpression. Thus, miR-550a-3p might play a role in atherosclerosis and, for the first time, normalised the function of injured vascular endothelial cells by simultaneous transfection of TM and miR-550a-3p. These results suggest that the miR-550a-3p/TM axis is a potential therapeutic target for atherosclerosis.

CPEB4 Inhibit Cell Proliferation via Upregulating p21 mRNA Stability in Renal Cell Carcinoma

Cytoplasmic polyadenylation element-binding protein 4 (CPEB4) has been reported to be dysregulated in a variety of cancers and seems to play paradoxical roles in different cancers. However, the functional roles of CPEB4 in Renal cell carcinoma (RCC) are still unclear. This study aims to explore the role and underlying mechanism of CPEB4 in RCC. We found that the relative expression level of CPEB4 is down-regulated in RCC tissues and cell lines, and the low CPEB4 expression is correlated with short overall and disease-free survival of RCC patients. CPEB4 significantly inhibits RCC tumor growth both in vivo and in vitro. CPEB4 exerts an anti-tumor effect by increasing p21 mRNA stability and inducing G1 cell cycle arrest in RCC. Our data revealed that CPEB4 is a tumor suppressor gene that restrains cell cycle progression upstream of p21 in RCC. These findings revealed that CPEB4 may become a promising predictive biomarker for prognosis in patients with RCC.

Investigation of the expression levels of CPEB4, APC, TRIP13, EIF2S3, EIF4A1, IFNg, PIK3CA and CTNNB1 genes in different stage colorectal tumors

Background/aim

The aim of the study is to assess expression levels of CPEB4, APC, TRIP13, EIF2S3, EIF4A1, IFNg, PIK3CA and CTNNB1 genes in tumors and peripheral bloods of colorectal cancer patients in stages I–IV.

Materials and methods

The mRNA levels of the genes were determined in tumor tissues and peripheral blood samples of 45 colorectal cancer patients and colon tissues and peripheral blood samples of 5 healthy individuals. Real-time polymerase chain reaction method was used for the analysis.

Results

The mRNA level of the CPEB4 gene was significantly downregulated in colorectal tumor tissues and was upregulated in the peripheral blood of colorectal cancer patients relative to the controls (P < 0.05). APC mRNA level was significantly downregulated in tissues and upregulated in the peripheral blood (P < 0.05). TRIP13 mRNA level was upregulated in peripheral blood and also significantly upregulated in colorectal tumor tissues (P < 0.05). EIF2S3 mRNA level was upregulated in tissues and also significantly upregulated in peripheral blood (P < 0.05). PIK3CA mRNA level was downregulated in tissues and upregulated in peripheral blood. EIF4A1 mRNA level was downregulated in tissues and significantly upregulated in peripheral blood (P < 0.05). CTNNB1 mRNA level was downregulated in tissues and upregulated in peripheral blood. IFNg mRNA level was upregulated in both colorectal cancer tumor tissues and peripheral blood.

Conclusion:

TRIP13 and CPEB4 mRNA up regulation in the peripheral blood of patients with colorectal cancer may be a potential target for early stage diagnosis. In addition to this evaluation, although there is not much study on EIF2S3 and EIF4A1 mRNA changes in cases with colorectal cancer, upregulation in peripheral blood draws attention in our study. These data will shed light on the new comprehensive studies.

MicroRNAs in the Pathogenesis of Hepatocellular Carcinoma: A Review

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most frequently occurring cancers, and the prognosis for late-stage HCC remains poor. A better understanding of the pathogenesis of HCC is expected to improve outcomes. MicroRNAs (miRNAs) are small, noncoding, single-stranded RNAs that regulate the expression of various target genes, including those in cancer-associated genomic regions or fragile sites in various human cancers. We summarize the central roles of miRNAs in the pathogenesis of HCC and discuss their potential utility as valuable biomarkers and new therapeutic agents for HCC.

Abstract

Hepatocellular carcinoma (HCC) is the seventh most frequent cancer and the fourth leading cause of cancer mortality worldwide. Despite substantial advances in therapeutic strategies, the prognosis of late-stage HCC remains dismal because of the high recurrence rate. A better understanding of the etiology of HCC is therefore necessary to improve outcomes. MicroRNAs (miRNAs) are small, endogenous, noncoding, single-stranded RNAs that modulate the expression of their target genes at the posttranscriptional and translational levels. Aberrant expression of miRNAs has frequently been detected in cancer-associated genomic regions or fragile sites in various human cancers and has been observed in both HCC cells and tissues. The precise patterns of aberrant miRNA expression differ depending on disease etiology, including various causes of hepatocarcinogenesis, such as viral hepatitis, alcoholic liver disease, or nonalcoholic steatohepatitis. However, little is known about the underlying mechanisms and the association of miRNAs with the pathogenesis of HCC of various etiologies. In the present review, we summarize the key mechanisms of miRNAs in the pathogenesis of HCC and emphasize their potential utility as valuable diagnostic and prognostic biomarkers, as well as innovative therapeutic targets, in HCC diagnosis and treatment.

LINC00261/microRNA-550a-3p/SDPR axis affects the biological characteristics of breast cancer stem cells

Long non-coding RNAs (lncRNAs) have been shown to play key roles in the pathogenesis of breast cancer (BC). The study was to explore the effect of long non-coding RNA LINC00261/microRNA (miR)-550a-3p/serum deprivation response (SDPR) axis on the biological characteristics of BC stem cells (BCSCs). BC and adjacent normal tissues of patients were collected. LINC00261, miR-550a-3p and SDPR expression in BC tissues and cell lines and CD24 and CD44 expression in BC tissues was detected. CD44⁺ /CD24^-/low BCSCs were sorted. CD44⁺ /CD24^-/low MDA-MB-231 and MCF-7 cells were screened and transfected with altered expression of LINC00261 or miR-550a-3p to explore their roles in cell viability, microsphere (MS) formation ability, migration and invasion of CD44⁺ /CD24^-/low BCSCs. The targeting relationships of LINC00261, miR-550a-3p and SDPR were detected. Reduced LINC00261, decreased SDPR and elevated miR-550a-3p exhibited in BC tissues of patients and cell lines. Elevated CD44^+/ CD24^- were present in BC tissues. LINC00261 up-regulated SDPR expression as a sponge of miR-550a-3p. Elevated LINC00261 suppressed BC cell viability, MS formation ability, migration and invasion of CD44⁺ /CD24^-/low BCSCs. Moreover, up-regulated miR-550a-3p reversed the inhibitive effect of elevated LINC00261 on BCSCs, and reduced SDPR reversed the promotive effect of decreased miR-550a-3p on BCSCs. The study highlights that LINC00261 can adsorb miR-550a-3p to modulate SDPR, thus inhibiting the viability and MS formation of BC cells, reducing migration and invasion of CD44⁺ /CD24^-/low BCSCs, exerting a potential effect on therapy.

miR-550a-3/NFIC plays a driving role in esophageal squamous cell cancer cells proliferation and metastasis partly through EMT process

In this study, the functional role of miR-550a-3 and its direct target nuclear factor IC (NFIC) in esophageal squamous cell cancer (ESCC) cells were explored. Differential expression of miR-550a-3 in ESCC tissues was acquired from TCGA database, and Kaplan-Meier method was used to determine the relationship between miR-550a-3 expression and survival time of ESCC patients. Expression level of miR-550a-3 in several ESCC cell lines was measured by qRT-PCR. Two cell lines including Eca109 and JAR were used to perform proliferation, cloning, invasion and migration experiments. Targeted relationship between miR-550a-3 and NFIC was speculated by predication software and confirmed by dual luciferase assay. Additionally, potential relationship between miR-550a-3 and NFIC was analyzed by Spearman rank correlation analysis and western blot. Rescue assays were performed to explore the function of miR-550a-3/NFIC in ESCC cells biological behaviors. Expression levels of key proteins involved in epithelial-to-mesenchymal transition (EMT) process were determined by western blot. By consulting TCGA database, we found that high expression of miR-550a-3 was positively connected with the poor prognosis of patients with ESCC. In addition, overexpression of miR-550a-3 promoted the proliferation, colony formation and metastasis of ESCC cells. Moreover, rescue assays revealed that overexpression of NFIC attenuated the promoting effects of miR-550a-3 on ESCC cells malignant behaviors. While the promoting effects of miR-550a-3 on EMT process were inhibited by NFIC. Our results illustrate the importance of miR-550a-3/NFIC in regulation of ESCC cells growth and metastasis, which could contribute to developing novel target for early diagnosis or neoteric therapeutic target for ESCC.

Novel MicroRNA Biomarkers, miR-142-5p, miR-550a, miR-1826, and miR-1201, Were Identified for Primary Melanoma

This study was aimed to identify novel miRNA biomarkers and explore the cooperative function of multi-RNAs in the progress of primary melanoma. The miRNA expression profile GSE62370 generated from 9 congenital nevi and 92 primary melanoma samples was downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs between primary melanoma and congenital nevi were compared and the target genes of them were selected. Pathway enrichment analysis and protein/protein interaction (PPI) network of miRNA target genes were performed. In addition, the differential expression of miRNAs to identify the tumor stage-dependent differences in miRNA expression was analyzed. Differentially expressed miRNAs, including 6 upregulated and 23 downregulated, were found in primary melanoma. Besides, the miRNA-associated gene regulatory network revealed 274 nodes, including miR-142-5p and miR-125b, and 307 miRNA-target pairs. miRNA-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, such as melanoma, was found. Target genes in the PPI module were mainly enriched in cancer-related pathways. Finally, the melanoma stage-related overexpressed miR-142-5p and the downregulated miR-550, miR-1826, miR-1201, miR-205, and miR-125b were identified. Some validated miRNAs, including miR-125a/b, let-7a/b, and miR-205, were found and illustrated the reliability of our study. Four novel miRNAs, including miR-142-5p, miR-550a, miR-1826, and miR-1201, were considered to have potential prognostic values for primary melanoma.

Tumor suppressor role of cytoplasmic polyadenylation element binding protein 2 (CPEB2) in human mammary epithelial cells

Background

Over-expression of cyclooxygenase (COX)-2 promotes breast cancer progression by multiple mechanisms, including induction of stem-like cells (SLC). Combined gene expression and microRNA microarray analyses of empty vector vs COX-2- transfected COX-2 low MCF7 breast cancer cell line identified two COX-2-upregulated microRNAs, miR-526b and miR-655, both found to be oncogenic and SLC-promoting. Cytoplasmic Polyadenylation Element-Binding Protein 2 (CPEB2) was the single common target of both microRNAs, the functions of which remain controversial. CPEB2 has multiple isoforms (A-F), and paradoxically, a high B/A ratio was reported to impart anoikis-resistance and metastatic phenotype in triple- negative breast cancer cells. We tested whether CPEB2 is a tumor suppressor in mammary epithelial cells.

Methods

We knocked-out CPEB2 in the non-tumorigenic mammary epithelial cell line MCF10A by CRISPR/Cas9-double nickase approach, and knocked-down CPEB2 with siRNAs in the poorly malignant MCF7 cell line, both lines being high CPEB2-expressing. The resultant phenotypes for oncogenity were tested in vitro for both lines and in vivo for CPEB2KO cells. Finally, CPEB2 expression was compared between human breast cancer and non-tumor breast tissues.

Results

CPEB2 (isoform A) expression was inversely correlated with COX-2 or the above microRNAs in COX-2-divergent breast cancer cell lines. CPEB2KO MCF10A cells exhibited oncogenic properties including increased proliferation, migration, invasion, EMT (decreased E-Cadherin, increased Vimentin, N-Cadherin, SNAI1, and ZEB1) and SLC phenotype (increased tumorsphere formation and SLC marker-expression). Tumor-suppressor p53 protein was shown to be a novel translationally-regulated target of CPEB2, validated with polysome profiling. CPEB2KO, but not wild-type cells produced lung colonies upon intravenous injection and subcutaneous tumors and spontaneous lung metastases upon implantation at mammary sites in NOD/SCID/IL2Rϒ-null mice, identified with HLA immunostaining. Similarly, siRNA-mediated CPEB2 knockdown in MCF7 cells promoted oncogenic properties in vitro. Human breast cancer tissues (n = 105) revealed a lower mRNA expression for CPEB2 isoform A and also a lower A/B isoform ratio than in non-tumour breast tissues (n = 20), suggesting that CPEB2A accounts for the tumor-suppressor functions of CPEB2.

Conclusions

CPEB2, presumably the isoform A, plays a key role in suppressing tumorigenesis in mammary epithelial cells by repressing EMT, migration, invasion, proliferation and SLC phenotype, via multiple targets, including a newly-identified translational target p53.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5771-5) contains supplementary material, which is available to authorized users.

miRNA-365b promotes hepatocellular carcinoma cell migration and invasion by downregulating SGTB

Aim: miR-365b, a miRNA at chromosomal breakpoint, was often amplified and upregulated in human hepatocellular carcinoma (HCC). However, the role of miR-365b dysregulation remains unclear. Materials & methods: miR-365b function assays and its target gene analyses were performed. Results: We revealed that miR-365b promoted HCC cell motility and spreading. Furthermore, SGTB was found to be a downstream target of miR-365b, and knockdown of the SGTB gene could mimic the effect of miR-365b in hastening HCC cell migration and invasion. Conclusion: These results imply that miR-365b plays a tumor-promoting role in HCC by suppressing SGTB expression, offering novel potential targets for the treatment of HCC.

MicroRNA-550a is associated with muscle system conferring poorer survival for esophageal cancer

Background Esophageal cancer (ESCA) is one of the most common cancers in the digestive tract. Approximately 300000 people on an average die of ESCA per year worldwide. The determination of key microRNAs for the prognosis of ESCA is of indispensable significance in the clinical treatment. Methods The differentially expressed microRNAs were screened by analyzing The Cancer Genome Atlas (TCGA) database. By using the survival data of the database, we analyzed correlation between patients’ survival time and miR-550a expression levels. Differential expression analysis and gene set enrichment analysis were performed using the targeted data. Results It was found that patients with high miR-550a expression levels had shorter survival time. Data mining and signal pathway enrichment analysis of TCGA database showed that abnormal miR-550a expressions affected the recurrence of tumors by the muscle system regulation. Conclusions Through the proposed investigation, miR-550a is found to be a potential biomarker as well as non-coding therapeutic target for esophagus cancer. These results suggest that miR-550a may serve as a therapeutic target and predictor for ESCA survival.

Validation of miRNA prognostic power in hepatocellular carcinoma using expression data of independent datasets

Multiple studies suggested using different miRNAs as biomarkers for prognosis of hepatocellular carcinoma (HCC). We aimed to assemble a miRNA expression database from independent datasets to enable an independent validation of previously published prognostic biomarkers of HCC. A miRNA expression database was established by searching the TCGA (RNA-seq) and GEO (microarray) repositories to identify miRNA datasets with available expression and clinical data. A PubMed search was performed to identify prognostic miRNAs for HCC. We performed a uni- and multivariate Cox regression analysis to validate the prognostic significance of these miRNAs. The Limma R package was applied to compare the expression of miRNAs between tumor and normal tissues. We uncovered 214 publications containing 223 miRNAs identified as potential prognostic biomarkers for HCC. In the survival analysis, the expression levels of 55 and 84 miRNAs were significantly correlated with overall survival in RNA-seq and gene chip datasets, respectively. The most significant miRNAs were hsa-miR-149, hsa-miR-139, and hsa-miR-3677 in the RNA-seq and hsa-miR-146b-3p, hsa-miR-584, and hsa-miR-31 in the microarray dataset. Of the 223 miRNAs studied, the expression was significantly altered in 102 miRNAs in tumors compared to normal liver tissues. In summary, we set up an integrated miRNA expression database and validated prognostic miRNAs in HCC.

A novel RNA sequencing-based miRNA signature predicts with recurrence and outcome of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer and the second leading cause of cancer-related deaths worldwide. Given that the rate of HCC recurrence 5 years after liver resection is as high as 70%, patient with HCC typically has a poor outcome. A biomarker or set of biomarkers that could predict disease recurrence would have a substantial clinical impact, allowing earlier detection of recurrence and more effective treatment. With the aim of identifying a new microRNA (miRNA) signature associated with HCC recurrence, we analyzed data on 306 patients with HCC for whom both miRNA expression profiles and complete clinical information were available from The Cancer Genome Atlas database. Through this analysis, we identified a six-miRNA signature that could effectively predict patients' recurrence risk; the high-risk and low-risk groups had significantly different recurrence-free survival rates. Time-dependent receiver operating characteristic analysis indicated that this signature had a good predictive performance. Multivariable Cox regression and stratified analyses demonstrated that the six-miRNA signature was independent of other clinical features. Functional enrichment analysis of the gene targets of the six prognostic miRNA indicated enrichment mainly in cancer-related pathways and important cell biological processes. Our results support use of this six-miRNA signature as an independent factor for predicting recurrence and outcome of patients with HCC.

Reduced miR-550a-3p leads to breast cancer initiation, growth, and metastasis by increasing levels of ERK1 and 2

Hyperactivation of the Ras/ERK pathway contributes to breast cancer initiation and progression, and recent evidence suggests aberrant signaling of miRNAs that regulate the Ras/ERK pathway play important roles during carcinogenesis and cancer progression. In this study, we demonstrate that miR-550a-3p expression is negatively correlated with levels of ERK1 and ERK2, two pivotal effectors in the Ras/ERK pathway. MiR-550a-3p gradually decreased during breast cancer initiation and progression and this reduction was a prognostic indicator of poorer overall survival (OS) and disease-free survival (DFS) among breast cancer patients. Our mechanistic studies demonstrated that miR-550a-3p exerts its tumor-suppressor role by directly repressing ERK1 and ERK2 protein expression, thereby suppressing the oncogenic ERK/RSK cascades, which reduced breast cancer cell viability, survival, migration, invasion, tumorigenesis, and metastasis. The inhibitory effects of miR-550a-3p were rescued by ectopic expression of ERK1 and/or ERK2. The novel connection between miR-550a-3p and ERK defines a new diagnostic and prognostic role for miR-550a-3p and highlights ERK inhibition as a candidate therapeutic target for breast cancers exhibiting hyperactivated Ras/ERK signaling.

Downregulated cytoplasmic polyadenylation element-binding protein-4 is associated with the carcinogenesis of head and neck squamous cell carcinoma

Cytoplasmic polyadenylation element-binding protein-4 (CPEB4) is involved in several biological processes that are associated with cancer progression. However, it remains unknown whether CPEB4 expression levels are associated with head and neck squamous cell carcinoma (HNSCC). The aim of the present study was to explore the potential function of CPEB4 in HNSCC. The expression of CPEB4 was analyzed in HNSCC from six Gene Expression Omnibus (GEO) datasets. Immunohistochemical staining was conducted to examine CPEB4 protein levels in an HNSCC tissue microarray (TMA). According to the GEO dataset analyses, CPEB4 gene expression was downregulated in HNSCC compared with normal samples (P<0.05). Notably, a statistical difference was observed between different tumor grades (P<0.05). Furthermore, the methylation of the CPEB4 gene in HNSCC was significantly increased compared with that observed in normal samples (P<0.01). The outcome from the TMA demonstrated that CPEB4 protein expression in human HNSCC tumors was significantly decreased compared with normal samples (P<0.05). In addition, the expression of CPEB4 protein was negatively associated with histological grades of HNSCC (P<0.05). The results from the present study suggested that CPEB4 may function as a tumor suppressor gene in HNSCC, which identifies the potential value of CPEB4 in predicting prognosis of HNSCC. Hypermethylation of the CPEB4 gene may be responsible for the downregulation of CPEB4 expression in HNSCC and result in tumorigenesis.

Circulating miRNAs as biomarkers for severe acute pancreatitis associated with acute lung injury

AIM

To identify circulating micro (mi)RNAs as biological markers for prediction of severe acute pancreatitis (SAP) with acute lung injury (ALI).

METHODS

Twenty-four serum samples were respectively collected and classified as SAP associated with ALI and SAP without ALI, and the miRNA expression profiles were determined by microarray analysis. These miRNAs were validated by quantitative reverse transcription-polymerase chain reaction, and their putative targets were predicted by the online software TargetScan, miRanda and PicTar database. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (commonly known as KEGG) were used to predict their possible functions and pathways involved.

RESULTS

We investigated 287 miRNAs based on microarray data analysis. Twelve miRNAs were differentially expressed in the patients with SAP with ALI and those with SAP without ALI. Hsa-miR-1260b, 762, 22-3p, 23b and 23a were differently up-regulated and hsa-miR-550a*, 324-5p, 484, 331-3p, 140-3p, 342-3p and 150 were differently down-regulated in patients with SAP with ALI compared to those with SAP without ALI. In addition, 85 putative target genes of the significantly dysregulated miRNAs were found by TargetScan, miRanda and PicTar. Finally, GO and pathway network analysis showed that they were mainly enriched in signal transduction, metabolic processes, cytoplasm and cell membranes.

CONCLUSION

This is the first study to identify 12 circulating miRNAs in patients with SAP with ALI, which may be biomarkers for prediction of ALI after SAP.

Overexpression of CPEB4 in glioma indicates a poor prognosis by promoting cell migration and invasion

Glioma is an aggressive malignancy with limited effective treatment and poor prognosis. Cytoplasmic polyadenylation element binding protein 4 is a regulator of gene transcription and has been reported to be associated with biological malignancy in cancers. However, the mechanisms that cytoplasmic polyadenylation element binding protein 4 contributes to tumor migration and invasion remain unknown. Here, cytoplasmic polyadenylation element binding protein 4 expression was assessed using immunohistochemistry, and the results were compared with clinicopathological parameters, including survival. Using glioma cell lines (SKMG-4 and T98G), we measured cytoplasmic polyadenylation element binding protein 4 messenger RNA and protein expression and studied the effects of cytoplasmic polyadenylation element binding protein 4 expression on cell migration and invasion. Cytoplasmic polyadenylation element binding protein 4 expression was significantly higher in tumor tissues than that in normal brain tissues. Clinicopathological analysis showed that cytoplasmic polyadenylation element binding protein 4 expression was significantly correlated with advanced World Health Organization grade ( p < 0.001) and lower Karnofsky Performance Status (KPS) score ( p = 0.001). Cytoplasmic polyadenylation element binding protein 4 positive as opposed to the cytoplasmic polyadenylation element binding protein 4 negative patients had lower overall survival ( p < 0.001). Multivariate analysis suggested that cytoplasmic polyadenylation element binding protein 4 expression might be an independent prognostic indicator (hazard ratio = 2.091, 95% confidence interval: 1.093-3.999, p = 0.026) for glioma patients. Moreover, upregulated cytoplasmic polyadenylation element binding protein 4 expression could promote T98G cell migration and invasion, and downregulated cytoplasmic polyadenylation element binding protein 4 expression could inhibit SKMG-4 cell migration and invasion. Furthermore, downregulated cytoplasmic polyadenylation element binding protein 4 could reduce the protein expression of matrix metalloproteinase-2 and matrix metalloproteinase-9. In conclusion, our studies indicated that positive cytoplasmic polyadenylation element binding protein 4 expression predicted a worse prognosis in glioma patients, and cytoplasmic polyadenylation element binding protein 4 could represent a useful biomarker or therapeutic target for glioma.

MetastamiRs: A promising choice for antihepatocellular carcinoma nucleic acid drug development

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide, which can be explained at least in part by its propensity towards metastasis and the limited efficacy of adjuvant therapy. MetastamiRs are miRNAs that promote or suppress migration and metastasis of cancer cells, and their functional status is significantly correlated with HCC prognosis. Unlike targeted therapy, metastamiRs have the potential to target multiple genes and signaling pathways and dramatically suppress cancer metastasis. In this review, we discuss the regulatory role of metastamiRs in the HCC invasion-metastasis cascade. Moreover, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis has shown that many extensively studied metastamiRs target several critical signaling pathways and these have remarkable therapeutic potential in HCC. The information reviewed here may assist in further anti-HCC miRNA drug screening and development.

Lineage-specific roles of the cytoplasmic polyadenylation factor CPEB4 in the regulation of melanoma drivers

Nuclear 3'-end-polyadenylation is essential for the transport, stability and translation of virtually all eukaryotic mRNAs. Poly(A) tail extension can also occur in the cytoplasm, but the transcripts involved are incompletely understood, particularly in cancer. Here we identify a lineage-specific requirement of the cytoplasmic polyadenylation binding protein 4 (CPEB4) in malignant melanoma. CPEB4 is upregulated early in melanoma progression, as defined by computational and histological analyses. Melanoma cells are distinct from other tumour cell types in their dependency on CPEB4, not only to prevent mitotic aberrations, but to progress through G1/S cell cycle checkpoints. RNA immunoprecipitation, sequencing of bound transcripts and poly(A) length tests link the melanoma-specific functions of CPEB4 to signalling hubs specifically enriched in this disease. Essential in these CPEB4-controlled networks are the melanoma drivers MITF and RAB7A, a feature validated in clinical biopsies. These results provide new mechanistic links between cytoplasmic polyadenylation and lineage specification in melanoma.

Cytoplasmic polyadenylated transcripts have been poorly characterized, particularly in cancer. Here the authors identify a lineage-specific requirement of the cytoplasmic polyadenylation binding protein 4 (CPEB4) in malignant melanoma and show that it controls melanoma drivers MITF and RAB27A.

High expression of cytoplasmic polyadenylation element-binding protein 4 correlates with poor prognosis of patients with colorectal cancer

Cytoplasmic polyadenylation element-binding protein 4 (CPEB4), a zinc-finger-containing sequence-specific RNA-binding protein, has been associated with tumor proliferation, invasion, and migration. Expression of CPEB4 and its prognostic significance in human colorectal cancer (CRC) have not been studied. The aim of the present study was to investigate expression of CPEB4 and its prognostic significance in CRC. Expression of CPEB4 in CRC tissues from two independent cohorts was examined by immunohistochemistry. Prognostic significance was analyzed using receiver operating characteristic curve analysis, Kaplan-Meier curves, and Cox regression analysis. High expression of CPEB4 was observed in 14.8 % of CRCs in the training cohort and 12.2 % of CRCs in the validation cohort. High expression of CPEB4 was significantly correlated with the pM classification, TNM stage, and poorer overall survival in both cohorts. Through multivariate Cox regression analysis, high expression of CPEB4 was found to be an independent prognostic biomarker for overall survival in CRC patients. High expression of CPEB4 may be an independent and useful biomarker for predicting the poor survival of patients with CRC.

Biphasic and Stage-Associated Expression of CPEB4 in Hepatocellular Carcinoma

Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a sequence-specific RNA-binding protein and translational regulator, with expression associated with tumor progression. Nevertheless, CPEB4 seems to play paradoxical roles in cancers–an oncogenic promoter in pancreatic ductal adenocarcinoma (PDA) and glioblastomas but a tumor suppressor in hepatocellular carcinoma (HCC). To assess whether CPEB4-regulated carcinogenesis is tissue-specific, we reevaluated the role of CPEB4 in HCC. Although proliferation of hepatocytes appeared normal in CPEB4-knockout (KO) mice after partial hepatectomy, knockdown (KD) of CPEB4 in HepG2 liver cancer cells promoted colony formation in vitro. Moreover, the growth of CPEB4-KD cells was accelerated in an in vivo xenograft mouse model. In tumorous and adjacent non-tumorous paired liver specimens from 49 HCC patients, the protein level of CPEB4 was significantly upregulated in early-stage HCC but decreased toward late-stage HCC. This finding agrees with changes in CPEB4 mRNA level from analysis of two sets of HCC microarray data from the Gene Expression Omnibus (GEO) database. Taken together, downregulation of CPEB4 likely occurs at the late cancer stage to facilitate HCC progression. Biphasic alteration of CPEB4 expression during HCC progression suggests its complicated role in tumorigenesis.

Dysregulated miRNA in progression of hepatocellular carcinoma: A systematic review

Hepatocellular carcinoma (HCC) is the fifth most frequent cancer and the third cause of cancer-related mortality worldwide. The primary risk factor for HCC is liver cirrhosis secondary to persistent infection with hepatitis B virus or hepatitis C virus. Although a number of cellular phenomena and molecular events have been reported to facilitate tumor initiation, progression and metastasis, the exact etiology of HCC has not yet been fully uncovered. miRNA, a class of non-coding RNA, negatively regulate post-transcriptional processes that participate in crucial biological processes, including development, differentiation, apoptosis and proliferation. In the liver, specific miRNA can be negative regulators of gene expression. Recent studies have uncovered the contribution of miRNA to cancer pathogenesis as they can function as oncogenes or tumor suppressor genes. In addition, other studies have demonstrated their potential value in the clinical management of patients with HCC as some miRNA may be used as prognostic or diagnostic markers. In this review, we summarize the current knowledge about the roles of miRNA in the carcinogenesis and progression of HCC.

Expression of CPEB4 in invasive ductal breast carcinoma and its prognostic significance

Aims

Cytoplasmic polyadenylation element binding proteins (CPEBs) are RNA-binding proteins that regulate translation by inducing cytoplasmic polyadenylation. CPEB4 has been reported in association with tumor growth, vascularization, and invasion in several cancers. To date, the expression of CPEB4 with clinical prognosis of breast cancer was never reported before. We aim to investigate the expression of CPEB4 and its prognostic significance in invasive ductal breast carcinoma.

Methods

Immunohistochemical staining of CPEB4 and estrogen receptor, progesterone receptor, and human epidermal growth factor receptor was performed in 107 invasive ductal carcinoma (IDC) samples, and prognostic significance was evaluated.

Results

High expression of CPEB4 was observed in 48.6% of IDC samples. Elevated CPEB4 expression was possibly related to increased histological grading (P=0.037) and N stage (P<0.001). Patients with high expression of CPEB4 showed shorter overall survival (P=0.001). High CPEB4 expression was an independent prognostic factor for overall survival (P=0.022, hazard ratio =4.344, 95% confidence interval =1.235–15.283).

Conclusion

High CPEB4 expression is associated with increased histological grading and N stage, and it can serve as an independent prognostic factor in IDC.

Function and clinical potential of microRNAs in hepatocellular carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs involved in the initiation and progression of several types of human cancer, including hepatocellular carcinoma (HCC), which is one of the most common types of cancer and the third leading cause of cancer-related mortality worldwide. Mounting evidence has demonstrated that miRNAs play a vital role in HCC, hepatitis, alcoholic liver disease, liver cell development and the metabolic functions of the liver. The aim of the present review was to summarize the most recent findings on the functions of miRNAs in the liver and discuss their potential roles in the diagnosis, prognosis and treatment of HCC.

Polymorphism in microRNA-binding site in HNF1B influences the susceptibility of type 2 diabetes mellitus: a population based case-control study

Background

Recent genome-wide association studies (GWAS) have identified many SNPs associated with type 2 diabetes mellitus (T2DM). However, the functional roles for most of the SNPs have not been elucidated. MicroRNAs (miRNAs) are key regulators of gene expression involved in the development and progression of various diseases including T2DM. In this study, we investigated whether commonly occurring SNPs modulate miRNA-directed regulation of gene expression, and whether such SNPs in miRNA-binding sites are associated with the susceptibility for T2DM.

Methods

Genotypes of eleven 3′ untranslated region (UTR) SNPs of seven susceptibility genes for T2DM were determined in 353 T2DM patients and 448 control subjects. In addition, the interactions of miRNAs with the 3′UTR in the hepatocyte nuclear factor 1β (HNF1B) gene were investigated using luciferase reporter assays.

Results

One 3′UTR SNP (rs2229295) in the HNF1B gene was significantly associated with T2DM, and the frequency of an A allele (rs2229295) in T2DM patients was decreased compared with that in controls. Luciferase reporter assays showed that the SNP (rs2229295) altered the binding of two miRNAs (hsa-miR-214-5p and hsa-miR-550a-5p).

Conclusions

We have detected the interactions of hsa-miR-214-5p/hsa-miR-550a-5p and the 3′UTR SNP of the HNF1B gene by in vitro luciferase reporter assays, and propose that the binding of such miRNAs regulates the expression of the HNF1B gene and the susceptibility of T2DM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0219-5) contains supplementary material, which is available to authorized users.

MicroRNAs dysregulation in hepatocellular carcinoma: Insights in genomic medicine

Hepatocellular carcinoma (HCC) is the leading primary liver cancer and its clinical outcome is still poor. MicroRNAs (miRNAs) have demonstrated an interesting potential to regulate gene expression at post-transcriptional level. Current findings suggest that miRNAs deregulation in cancer is caused by genetic and/or epigenetic, transcriptional and post-transcriptional modifications resulting in abnormal expression and hallmarks of malignant transformation: aberrant cell growth, cell death, differentiation, angiogenesis, invasion and metástasis. The important role of miRNAs in the development and progression of HCC has increased the efforts to understand and develop mechanisms of control overt this single-stranded RNAs. Several studies have analyzed tumoral response to the regulation and control of deregulated miRNAs with good results in vitro and in vivo, proving that targeting aberrant expression of miRNAs is a powerful anticancer therapeutic. Identification of up and/or down regulated miRNAs related to HCC has led to the discovery of new potential application for detection of their presence in the affected organism. MiRNAs represent a relevant new target for diagnosis, prognosis and treatment in a wide variety of pathologic entities, including HCC. This manuscript intends to summarize current knowledge regarding miRNAs and their role in HCC development.

Brg-1 targeting of novel miR550a-5p/RNF43/Wnt signaling axis regulates colorectal cancer metastasis

Metastasis is one of the main causes of death in patients with colorectal cancer (CRC). Brg-1 is a central component of the SWItch/Sucrose NonFermentable chromatin-remodeling complex, which features a bromodomain and helicase/ATPase activity. The gene encoding Brg-1 is frequently mutated or silenced in human cancers. Several reports have proposed Brg-1 as a tumor suppressor; however, little is known about its role in oncogenesis and metastasis. Here we demonstrated that decreased Brg-1 regulates a novel miR-550a-5p/RNF43/Wnt/β-catenin signaling pathway, to promote CRC metastasis in vitro and in vivo. In particular, we used high-throughput RNA-sequencing analysis to show that Brg-1 negatively regulates miR-550a-5p in CRC cells. We further found that Brg-1 inhibits the transcriptional activity of miR-550a-5p promoter, and that decreased Brg-1 expression increased miR-550a-5p expression. We also identified ring finger 43 (RNF43), an inhibitor of Wnt/β-catenin signaling, as a target of miR-550a-5p. Knockdown of Brg-1 by small interfering RNA led to decreased RNF43 expression, increased Wnt signaling and increased CRC cell migration and invasion. This novel pathway defines a new function for Brg-1 and provides potential targets for the treatment of Brg-1 mutant and loss-of-function tumors.

Fibroblasts from patients with major depressive disorder show distinct transcriptional response to metabolic stressors

Major depressive disorder (MDD) is increasingly viewed as interplay of environmental stressors and genetic predisposition, and recent data suggest that the disease affects not only the brain, but the entire body. As a result, we aimed at determining whether patients with major depression have aberrant molecular responses to stress in peripheral tissues. We examined the effects of two metabolic stressors, galactose (GAL) or reduced lipids (RL), on the transcriptome and miRNome of human fibroblasts from 16 pairs of patients with MDD and matched healthy controls (CNTR). Our results demonstrate that both MDD and CNTR fibroblasts had a robust molecular response to GAL and RL challenges. Most importantly, a significant part (messenger RNAs (mRNAs): 26-33%; microRNAs (miRNAs): 81-90%) of the molecular response was only observed in MDD, but not in CNTR fibroblasts. The applied metabolic challenges uncovered mRNA and miRNA signatures, identifying responses to each stressor characteristic for the MDD fibroblasts. The distinct responses of MDD fibroblasts to GAL and RL revealed an aberrant engagement of molecular pathways, such as apoptosis, regulation of cell cycle, cell migration, metabolic control and energy production. In conclusion, the metabolic challenges evoked by GAL or RL in dermal fibroblasts exposed adaptive dysfunctions on mRNA and miRNA levels that are characteristic for MDD. This finding underscores the need to challenge biological systems to bring out disease-specific deficits, which otherwise might remain hidden under resting conditions.

miRNA in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Despite improvements in HCC therapy, the prognosis for HCC patients remains poor due to a high incidence of recurrence. An improved understanding of the pathogenesis of HCC development would facilitate the development of more effective outcomes for the diagnosis and treatment of HCC at earlier stages. miRNA are small, endogenous, non-coding, ssRNA that are 21-30 nucleotides in length and modulate the expression of various target genes at the post-transcriptional and translational levels. Aberrant expression of miRNA is common in various human malignancies and modulates cancer-associated genomic regions or fragile sites. As for the relationship between miRNA and HCC, several studies have demonstrated that the aberrant expression of specific miRNA can be detected in HCC cells and tissues. However, little is known about the mechanisms of miRNA-related cell proliferation and development. In this review, we summarize the central and potential roles of miRNA in the pathogenesis of HCC and elucidate new possibilities that may be useful as diagnostic and prognostic markers, as well as novel therapeutic targets in HCC.

miRNAs affect the development of hepatocellular carcinoma via dysregulation of their biogenesis and expression

The pathogenesis of hepatocellular carcinoma (HCC) is not fully understood, which has affected the early diagnosis and treatment of HCC and the survival time of patients. MicroRNAs (miRNAs) are a class of evolutionarily conserved small, non-coding RNAs, which regulate the expression of various genes post-transcriptionally. Emerging evidence indicates that the key enzymes involved in the miRNA biosynthesis pathway and some tumor-specific miRNAs are widely deregulated or upregulated in HCC and closely associated with the occurrence and development of various cancers, including HCC. Early studies have shown that miRNAs have critical roles in HCC progression by targeting many critical protein-coding genes, thereby contributing to the promotion of cell proliferation; the avoidance of apoptosis, inducing via angiogenesis; and the activation of invasion and metastasis pathways. Experimental data indicate that discovery of increasing numbers of aberrantly expressed miRNAs has opened up a new field for investigating the molecular mechanism of HCC progression. In this review, we describe the current knowledge about the roles and validated targets of miRNAs in the above pathways that are known to be hallmarks of HCC, and we also describe the influence of genetic variations in miRNA biosynthesis and genes.

Genome-wide screening identified that miR-134 acts as a metastasis suppressor by targeting integrin β1 in hepatocellular carcinoma

MicroRNAs (miRNAs) are small, single-stranded, non-coding RNAs that play pivotal roles in human cancer development and progression, such as tumor metastasis. Here, we identified the miRNAs that regulate hepatocellular carcinoma (HCC) cell migration by a high-throughput screening method using the classical wound-healing assay with time-lapse video microscopy and validation with a transwell migration assay. Eleven miRNAs (miR-134, -146b-3p, -188-3p, -525-3p, -661, -767-5p, -891a, -891b, -1244, -1247 and miR-1471) were found to promote or inhibit HCC cell migration. Further investigation revealed that miR-134 suppressed the invasion and metastasis of HCC cells in vitro and in vivo, and integrin beta 1 (ITGB1) was a direct and functional target gene of miR-134. Moreover, miR-134 inhibited the phosphorylation of focal adhesion kinase (FAK) and the activation of RhoA downstream of the ITGB1 pathway, thereby decreasing stress fiber formation and cell adhesion in HCC cells. In conclusion, we demonstrated that miR-134 is a novel metastasis suppressor in HCC and could be a potential therapeutic target for the treatment of HCC.

New insights on the role of epigenetic alterations in hepatocellular carcinoma

Emerging evidence assigns to epigenetic mechanisms heritable differences in gene function that come into being during cell development or via the effect of environmental factors. Epigenetic deregulation is strongly involved in the development of hepatocellular carcinoma (HCC). It includes changes in methionine metabolism, promoter hypermethylation, or increased proteasomal degradation of oncosuppressors, as well as posttranscriptional deregulation by microRNA or messenger RNA (mRNA) binding proteins. Alterations in the methylation of the promoter of methyl adenosyltransferase MAT1A and MAT2A genes in HCC result in decreased S-adenosylmethionine levels, global DNA hypomethylation, and deregulation of signal transduction pathways linked to methionine metabolism and methyl adenosyltransferases activity. Changes in S-adenosylmethionine levels may also depend on MAT1A mRNA destabilization associated with MAT2A mRNA stabilization by specific proteins. Decrease in MAT1A expression has also been attributed to miRNA upregulation in HCC. A complex deregulation of miRNAs is also strongly involved in hepatocarcinogenesis, with up-regulation of different miRNAs targeting oncosuppressor genes and down-regulation of miRNAs targeting genes involved in cell-cycle and signal transduction control. Oncosuppressor gene down-regulation in HCC is also induced by promoter hypermethylation or posttranslational deregulation, leading to proteasomal degradation. The role of epigenetic changes in hepatocarcinogenesis has recently suggested new promising therapeutic approaches for HCC on the basis of the administration of methylating agents, inhibition of methyl adenosyltransferases, and restoration of the expression of tumor-suppressor miRNAs.

MicroRNA-192 suppresses liver metastasis of colon cancer

Metastasis causes most deaths from colon cancer yet mechanistic understanding and therapeutic options remain limited. Here we show that expression of microRNA (miR)-192 is inversely correlated with metastatic potential of colon cancer cells. Ectopic expression of miR-192 sensitizes colon cancer cells to growth factor deprivation stress (GFDS)-induced apoptosis whereas inhibition of miR-192 confers resistance. Overexpression of miR-192 inhibits metastatic colonization to the liver in an orthotopic mouse model of colon cancer. Alterations associated with the metastatic phenotype in the primary tumors include increased apoptosis, decreased proliferation and angiogenesis. Further studies indicate that miR-192 down-regulates expression of Bcl-2, Zeb2 and VEGFA in vitro and in vivo, which is responsible for enhanced apoptosis, increased expression of E-cadherin and decreased angiogenesis in vivo respectively. Finally, studies performed on human colonic adenocarcinoma show that expression of miR-192 is significantly reduced in neoplastic cells as compared to normal colonic epithelium. Importantly, there is a significant decrease of miR-192 expression in stage IV tumors when compared to stage I or II lesions. These findings indicate that miR-192 plays an important role in colon cancer development and progression. Our studies underscore the clinical relevance and prognostic significance of miR-192 expression in colon cancer. Therefore, a major implication of our studies is that restoration of miR-192 expression or antagonism of its target genes (Bcl-2, Zeb2 or VEGFA) may have considerable therapeutic potential for anti-metastatic therapy in patients with colon cancer.

Regulation of onco and tumor suppressor MiRNAs by mTORC1 inhibitor PRP-1 in human chondrosarcoma

Metastatic chondrosarcoma of mesenchymal origin is the second most common bone malignancy and does not respond either to chemotherapy or radiation; therefore, the search for new therapies is relevant and urgent. This study aimed to reveal the comparative analysis of miRNAs and their targets in human JJ012 chondrosarcoma cell line between control and experimental samples, treated with mTORC1 inhibitor, cytostatic antiproliferative proline-rich polypeptide (PRP-1). Examination of tumor-specific microRNA expression profiles has revealed widespread deregulation of these molecules in diverse cancers. It was reported that microRNAs can function as novel biomarkers for disease diagnostics and therapy, as well as a novel class of oncogenes and tumor suppressor genes. mTORC 1 inhibitor PRP-1 caused significant upregulation of tumor suppressors, such as miR20a, miR125b, and miR192; and downregulation of onco miRNAs, miR509-3p, miR589, miR490-3p, miR 550 in human chondrosarcoma JJ012 cell line.

MicroRNAs: regulators of cancer metastasis and epithelial-mesenchymal transition (EMT)

Tumor metastasis is the main cause of death in patients with solid tumors. The epithelial-mesenchymal transition (EMT) process, in which epithelial cells are converted into mesenchymal cells, is frequently activated during cancer invasion and metastasis. MicroRNAs (miRNAs) are small, non-coding RNAs that provide widespread expressional control by repressing mRNA translation and inducing mRNA degradation. The fundamental roles of miRNAs in tumor growth and metastasis have been increasingly well recognized. A growing number of miRNAs are reported to regulate tumor invasion/metastasis through EMT-related and/or non-EMT- related mechanisms. In this review, we discuss the functional role and molecular mechanism of miRNAs in regulating cancer metastasis and EMT.

Clinical implications of microRNAs in liver cancer stem cells

The prognosis of patients diagnosed with hepatocellular carcinoma (HCC) is often dismal, mainly due to late presentation, high recurrence rate, and frequent resistance to chemotherapy and radiotherapy. Accumulating evidence on the differential microRNA (miRNA) expression patterns between non-tumor and HCC tissues or between liver cancer stem cells (CSCs) and non-CSC subsets and the significant clinical implications of these differences suggest that miRNAs are a promising, non-invasive marker for the prognosis and diagnosis of the disease. This perspective article summarizes the current knowledge of miRNAs in liver CSCs and highlights the need for further investigations of the role of miRNAs in regulating liver CSC subsets for possible future clinical applications.

microRNAs and RNA-binding proteins: a complex network of interactions and reciprocal regulations in cancer

In the last decade, an ever-growing number of connections between microRNAs (miRNAs) and RNA-binding proteins (RBPs) have uncovered a new level of complexity of gene expression regulation in cancer. In this review, we examine several aspects of the functional interactions between miRNAs and RBPs in cancer models. We will provide examples of reciprocal regulation: miRNAs regulating the expression of RBPs, or the converse, where an RNA-binding protein specifically regulates the expression of a specific miRNA, or when an RBP can exert a widespread effect on miRNAs via the modulation of a key protein for miRNA production or function. Moreover, we will focus on the ever-growing number of functional interactions that have been discovered in the last few years: RBPs that were shown to cooperate with microRNAs in the downregulation of shared target mRNAs or, on the contrary, that inhibit microRNA action, thus resulting in a protection of the specific target mRNAs. We surely need to obtain a deeper comprehension of such intricate networks to have a chance of understanding and, thus, fighting cancer.

MicroRNAs in hepatocellular carcinoma: regulation, function, and clinical implications

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and the third cause of cancer-related death. Poor understanding of the mechanisms underlying the pathogenesis of HCC makes it difficult to be diagnosed and treated at early stage. MicroRNAs (miRNAs), a class of noncoding single-stranded RNAs of ~22 nucleotides in length, posttranscriptionally regulate gene expression by base pairing with the 3' untranslated regions (3'UTRs) of target messenger RNAs (mRNAs). Aberrant expression of miRNAs is found in many if not all cancers, and many deregulated miRNAs have been proved to play crucial roles in the initiation and progression of cancers by regulating the expression of various oncogenes or tumor suppressor genes. In this Paper, we will summarize the regulations and functions of miRNAs aberrantly expressed in HCC and discuss the potential application of miRNAs as diagnostic and prognostic biomarkers of HCC and their potential roles in the intervention of HCC.