miR-204-5p expression in colorectal cancer: an autophagy-associated gene

Deregulation of exosomal miRNAs in rheumatoid arthritis patients

Exosomes are small-diameter endosomal vesicles secreted in all biological fluids and play biological/pathological roles in the cell. These pathological roles are played by exosome's cargo molecules through inter-cellular communication. Exosomal cargo molecules contain proteins and miRNAs. miRNAs are small non-coding RNA fragments involved in the reduction of final protein output by destabilizing or suppressing the translation of target messenger RNA (mRNA). This deregulation of the protein due to miRNAs ultimately accelerates the process of disease pathogenesis. The role of exosomal miRNAs has been investigated in different diseases and the limited number of studies have been published concerning exosomal miRNAs and rheumatoid arthritis (RA). The current study is designed to investigate the role of exosomal miRNAs (miRNA-103a-3p, miRNA-10a-5p, miRNA-204-3p, miRNA-330-3p, and miRNA-19b) in the pathogenesis of RA. Furthermore, the role of selected exosomal miRNAs in RA pathogenesis was further explored by estimating oxidative stress and histone deacetylation in RA patients. In the current study, 306 RA patients and equal numbers of age/gender-matched controls were used. The level of expression of above-mentioned exosomal miRNAs was assessed by performing qRT PCR. Deacetylation and oxidative stress assays were performed to estimate the 8-hydroxydeoxyguanosine (8-OHdG level) and histone deacetylation levels using the Enzyme-linked immunosorbent assay (ELISA). Statistical analysis indicated a significantly downregulated expression of miRNA-103a-3p (p<0.0001), miR-10a-5p (p<0.0001), miR-204-3p (p<0.0001), miR-330-3p (p<0.0001) and miR-19b (p<0.0001) in RA patients compared to controls. Significantly increased levels of 8-OHdG (p<0.0001) and histone deacetylation (p<0.0001) were observed among RA patients compared to controls. Spearman correlation showed a negative correlation between the deregulated exosomal miRNAs and increased oxidative stress and histone deacetylation in RA patients. Receiver operating characteristics (ROC) curve analysis showed a good diagnostic specificity/sensitivity of the above-mentioned exosomal miRNAs among RA patients. These analyses indicated the potential role of deregulated exosomal miRNAs in the initiation of RA by targeting oxidative stress and histone deacetylation processes.

Development of Electrochemical Biosensor for miR204-Based Cancer Diagnosis

With increase in cancer burden worldwide and poor survival rates due to delayed diagnosis, it is pertinent to develop a device for early diagnosis. We report an electrochemical biosensor for quantification of miRNA-204 (miR-204) biomarker that is dysregulated in most of the cancers. The proposed methodology uses the gold nanoparticles-modified carbon screen-printed electrode for immobilization of single-stranded DNA probe against miR-204. Colloidal gold nanoparticles were synthesized using L-glutamic acid as reducing agent. Nanoparticles were characterized by UV-visible spectroscopy and transmission electron microscopy. Spherical gold nanoparticles were of 7-28 nm in size. Biosensor fabricated using these nanoparticles was characterized by cyclic voltammetry after spiking 0.1 fg/mL-0.1 µg/mL of miR-204 in fetal bovine serum. Response characteristics of the miR-204 biosensor displayed high sensitivity of 8.86 µA/µg/µL/cm² with wide detection range of 15.5 aM to 15.5 nM. The low detection limit makes it suitable for early diagnosis and screening of cancer.

The role of non-coding RNAs in chemotherapy for gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, hepatic, esophageal, and pancreatic tumors, are responsible for large numbers of deaths around the world. Chemotherapy is the most common approach used to treat advanced GI cancer. However, chemoresistance has emerged as a critical challenge that prevents successful tumor elimination, leading to metastasis and recurrence. Chemoresistance mechanisms are complex, and many factors and pathways are involved. Among these factors, non-coding RNAs (ncRNAs) are critical regulators of GI tumor development and subsequently can induce resistance to chemotherapy. This occurs because ncRNAs can target multiple signaling pathways, affect downstream genes, and modulate proliferation, apoptosis, tumor cell migration, and autophagy. ncRNAs can also induce cancer stem cell features and affect the epithelial-mesenchymal transition. Thus, ncRNAs could possibly act as new targets in chemotherapy combinations to treat GI cancer and to predict treatment response.

miR-181b and miR-204 suppress the VSMC proliferation and migration by downregulation of HCK

BACKGROUND

VSMC proliferation and migration pathways play important roles in plaque formation in the vessel stenosis and re-stenosis processes. The microRNAs affect the expression of many genes that regulate these cellular processes. The aim of this study was to investigate the effects of miR-181b, miR-204, and miR-599 on the gene and protein expression levels of hematopoietic cell kinase (HCK) in VSMCs.

METHODS

miR-181b, miR-204 were predicted for the suppression of HCK in the chemokine signaling pathway using bioinformatics tools. Then, the VSMCs were transfected by PEI-containing microRNAs. The HCK gene and protein expression levels were evaluated using RT-qPCR and Western blotting techniques, respectively. Moreover, the cellular proliferation and migration were evaluated by MTT and scratch assay methods.

RESULTS

The miR-181b and miR-204 decreased significantly the HCK gene and (total and phosphorylated) protein expression levels. Also, the miR-599 did not show any significant effects on the HCK gene and protein levels. The data also showed that miR-181b, miR-204, and miR-599 prevent significantly the proliferation and migration of VSMCs.

CONCLUSION

The downregulation of HCK by miR-181b and miR-204 suppressed the VSMC proliferation and migration.

Sufentanil Inhibits Proliferation, Migration, and Invasion of Hepatocellular Carcinoma Cells by Upregulating miRNA-204

Sufentanil is a powerful analgesic that acts on μ-receptors, but there are few studies on sufentanil in cancer. The biological function and underlying mechanisms of sufentanil on the hepatocellular carcinoma (HCC) cells were explored in the present study. HCC cells were first treated with different concentrations of sufentanil and the most optimum concentration of sufentanil was determined. The expression of miR-204 in HCC cells was changed by transfected with miR-204 inhibitor and the transfection efficiency was assessed by qRT-PCR. CCK-8, wound-healing and Transwell assays were performed to evaluate the proliferation, migration and invasion of HCC cells, respectively. The level of AKT and PI3K phosphorylation (p-AKT and p-PI3K) were assessed by western blot analysis. Our results demonstrated that sufentanil effectively inhibited cell proliferation,migration and invasion in both Huh7 and Hep3B cells, and significantly decreased the expression of p-AKT and p-PI3K. In addition, miR-204 was upregulated in Huh7 and Hep3B cells treated with sufentanil, and low expression of miR-204 attenuated the damage of sufentanil on the viability of Huh7 and Hep3B cells. Taken together, sufentanil suppressed the proliferation, migration and invasion of HCC cells via inhibiting AKT/PI3K signaling pathway by targeting miR-204.

Investigation the Role of Autophagy in Non-Small Cell Lung Cancer

Objective:

Recent studies have shown the role of autophagy in different types of cancer including lung cancer. MicroRNAs are considered as key factors in regulation of autophagy related genes. miR-30d, miR-204-5p and miR-20a are regulatory markers which can suppress the expression of beclin1, LC3, bcl2 and ULK1 as their target genes and they lead to decrement of autophagy in human cancer cells. Moreover, epigenetic modifications DNA methylation has been indicated in regulation of autophagy in different stages of cancer.

Methods:

In this study, the expression levels of miR-30d, miR-204-5p and miR-20a as well as their target genes were analyzed in 30 non-small cell lung cancers (NSCLCs) patients sample and adjacent normal tissues by real-time qPCR. In addition, DNA methylation of beclin1, LC3, bcl2 and ULK1 genes were assessed by MS-HRM method.

Results:

MiR-30d (p value= 0.01) and miR-204-5p (P=0.048) significantly down-regulated in tumor samples compared to normal adjacent tissues, while there was no significant change in expression level of miR-20a. On the other hand, target genes expression level was significantly increased in NSCLC tissues, however methylation pattern of the target gene promoters, did not show any significant alteration.

Conclusion:

These results indicate roles for miR-30d, miR-204-5p as tumor suppressor genes as well as target genes as oncogenes in NSCLC patients. Although these factors may have a significant role in NSCLC progression, further studies are necessary to investigate the implications of these findings for treatment of lung cancer.

Key Regulatory miRNAs and their Interplay with Mechanosensing and Mechanotransduction Signaling Pathways in Breast Cancer Progression

According to the WHO, breast cancer is the most common cancer in women worldwide. Identification of underlying mechanisms in breast cancer progression is the main concerns of researches. The mechanical forces within the tumor microenvironment, in addition to biochemical stimuli such as different growth factors and cytokines, activate signaling cascades, resulting in various changes in cancer cell physiology. Cancer cell proliferation, invasiveness, migration, and, even, resistance to cancer therapeutic agents are changed due to activation of mechanotransduction signaling. The mechanotransduction signaling is frequently dysregulated in breast cancer, indicating its important role in cancer cell features. So far, a variety of experimental investigations have been conducted to determine the main regulators of the mechanotransduction signaling. Currently, the role of miRNAs has been well-defined in the cancer process through advances in molecular-based approaches. miRNAs are small groups of RNAs (∼22 nucleotides) that contribute to various biological events in cells. The central role of miRNAs in the regulation of various mediators involved in the mechanotransduction signaling has been well clarified over the last decade. Unbalanced expression of miRNAs is associated with different pathologic conditions. Overexpression and downregulation of certain miRNAs were found to be along with dysregulation of mechanotransduction signaling effectors. This study aimed to critically review the role of miRNAs in the regulation of mediators involved in the mechanosensing pathways and clarify how the cross-talk between miRNAs and their targets affect the cell behavior and physiology of breast cancer cells.

microRNA-204-5p Participates in Atherosclerosis Via Targeting MMP-9

The aim of the present study was to investigate the role and mechanism of microRNA-204-5p (miR-204-5p) in atherosclerosis (AS)-related abnormal human vascular smooth muscle cells (hVSMCs) function. Firstly, we analyzed the expression of miR-204-5p and found that the miR-204-5p expression level was clearly downregulated in atherosclerotic plaque tissues and blood samples compared to the normal controls. Then, matrix metallopeptidase-9 (MMP-9) was predicted to be the potential target of miR-204-5p by TargetScan and this prediction was confirmed by luciferase assays. Besides, we observed that miR-204-5p could negatively regulate the expression of MMP-9 in hVSMCs. Subsequently, Thiazolyl Blue Tetrazolium Bromide (MTT) assay, transwell assay and flow cytometry were performed to detect the proliferation, migration and apoptosis of hVSMCs. Down-expression of miR-204-5p led to the promotion of proliferation and migration accompanied with the suppression of apoptosis in hVSMCs, and these effects were reversed by MMP-9-siRNA. In addition, overexpressed miR-204-5p could inhibit hVSMC proliferation and migration and promote the apoptosis of hVSMCs. However, the effects were also abrogated by overexpressed MMP-9. Together, our findings showed that miR-204-5p plays an important role in the growth and migration of hVSMCs by targeting MMP-9, which might be a novel biomarker and promising therapeutic target for AS.

Long Noncoding RNA KCNQ1OT1 Promotes the Progression of Non-Small Cell Lung Cancer via Regulating miR-204-5p/ATG3 Axis

Purpose

Non-small cell lung cancer (NSCLC) is the first leading cause of cancer-related death globally. Long noncoding RNA KCNQ1 overlapping transcript 1 (KCNQ1OT1) was involved in the progression of multiple cancers by sponging target miRNA. We aimed to explore the pathological mechanism of KCNQ1OT1 in NSCLC progression.

Methods

The expression of KCNQ1OT1, miR-204-5p and autophagy-related gene 3 (ATG3) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry assay were conducted for the detection of cell proliferation and apoptosis, respectively. Western blot assay was performed to examine the protein levels of B-cell lymphoma-2 (BCL-2), BCL2-Associated X (Bax), cleaved caspase-3, cleaved caspase-9 and LC3Ⅱ/LC3Ⅰ and P62. The interaction between miR-204-5p and KCNQ1OT1 or ATG3 was validated by dual-luciferase reporter system and RNA immunoprecipitation (RIP) assay. Murine xenograft assay was conducted to explore the function of KCNQ1OT1 in vivo. Immunohistochemistry (IHC) staining assay was used for the analysis of ki67-positive cell percentage.

Results

The expression of KCNQ1OT1 and ATG3 was up-regulated whereas miR-204-5p was down-regulated in NSCLC tumors and cells. MiR-204-5p was inversely correlated with KCNQ1OT1 or ATG3. In addition, KCNQ1OT1 knockdown facilitated apoptosis, inhibited autophagy and proliferation of NSCLC cells in vitro and blocked tumor growth in vivo. However, the miR-204-5p inhibitor reversed the effects. More importantly, ATG3 was a target gene of miR-204-5p and ATG3 overexpression restored the effect of miR-204-5p on NSCLC cell progression.

Conclusion

KCNQ1OT1 promotes cell proliferation and autophagy and inhibits cell apoptosis via regulating miR-204-5p/ATG3 axis, providing a promising target for NSCLC therapy.

Interaction among inflammasome, autophagy and non-coding RNAs: new horizons for drug

Autophagy and inflammasomes are shown to interact in various situations including infectious disease, cancer, diabetes and neurodegeneration. Since multiple layers of molecular regulators contribute to the interplay between autophagy and inflammasome activation, the detail of such interplay remains largely unknown. Non-coding RNAs (ncRNAs), which have been implicated in regulating an expanding list of cellular processes including immune defense against pathogens and inflammatory response in cancer and metabolic diseases, may join in the crosstalk between inflammasomes and autophagy in physiological or disease conditions. In this review, we summarize the latest research on the interlink among ncRNAs, inflammasomes and autophagy and discuss the emerging role of these three in multiple signaling transduction pathways involved in clinical conditions. By analyzing these intriguing interconnections, we hope to unveil the mechanism inter-regulating these multiple processes and ultimately discover potential drug targets for some refractory diseases.

MiR-204 inhibits hepatocellular cancer drug resistance and metastasis through targeting NUAK1

Liver cancer is a leading cause of cancer-related deaths globally. Tumor response rate of liver cancer patients towards systemic chemotherapy is low and chemoresistance can easily develop. Identifying novel molecules that can repress drug resistance and metastasis of liver cancer will facilitate the development of new therapeutic strategies. The aim of this study is to determine the roles of NUAK1 and miR-204 in the drug resistance and metastasis of liver cancer and to reveal their relationship. We found that NUAK1 was increased in the tumor of primary liver cancer. Knockdown of NUAK1 significantly inhibited cell growth and migration. Moreover, NUAK1 was the direct downstream target of miR-204, and there was clinical relevance between miR-204 down-regulation and NUAK1 up-regulation in liver cancer. Furthermore, we found that miR-204 increased drug sensitivity by down-regulating NUAK1 expression. Based on these results, we identified miR-204 as a tumor suppressor by inhibiting NUAK1 expression in liver cancer, indicating both miR-204 and NUAK1 may act as promising targets for liver cancer therapy.

Epigenetic Regulation by lncRNAs: An Overview Focused on UCA1 in Colorectal Cancer

Colorectal cancers have become the second leading cause of cancer-related deaths. In particular, acquired chemoresistance and metastatic lesions occurring in colorectal cancer are a major challenge for chemotherapy treatment. Accumulating evidence shows that long non-coding (lncRNAs) are involved in the initiation, progression, and metastasis of cancer. We here discuss the epigenetic mechanisms through which lncRNAs regulate gene expression in cancer cells. In the second part of this review, we focus on the role of lncRNA Urothelial Cancer Associated 1 (UCA1) to integrate research in different types of cancer in order to decipher its putative function and mechanism of regulation in colorectal cancer cells. UCA1 is highly expressed in cancer cells and mediates transcriptional regulation on an epigenetic level through the interaction with chromatin modifiers, by direct regulation via chromatin looping and/or by sponging the action of a diversity of miRNAs. Furthermore, we discuss the role of UCA1 in the regulation of cell cycle progression and its relation to chemoresistance in colorectal cancer cells.

Inhibition of MicroRNA-204 Conducts Neuroprotection Against Spinal Cord Ischemia

BACKGROUND

MicroRNA(miR)-204 is an autophagy- and apoptosis-related gene. Neuroprotection by the inhibition of miR-204 against spinal cord ischemia was evaluated, and the roles of neuronal autophagy and apoptosis were investigated.

METHODS

Spinal cord ischemia was conducted in rats by cross-clamping the descending aorta for 14 minutes. Inhibition of miR-204 was induced by intrathecal injection of lentivirus vectors containing antagomiR-204. Hind-limb motor function was assessed with the motor deficit index. Lumbar spinal cords were harvested for histologic examinations and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling staining. Autophagy was evaluated by the LC3-II/LC3-I ratio and beclin-1 expression. Expressions of LC3-I, LC3-II, beclin-1, B-cell lymphoma-2 (BCL-2), caspase-3, and miR-204 were measured by Western blot and quantitative real-time polymerase chain reaction. Autophagy was blocked by 3-methyladenine.

RESULTS

Transient ischemia enhanced miR-204 expression and the LC3-II/LC3-I ratio and downregulated BCL-2 expression in spinal cords in a time-dependent manner. AntagomiR-204 significantly reduced expressions of miR-204 and caspase-3, dramatically upregulated expressions of beclin-1 and BCL-2 and the LC3-II/LC3-I ratio in spinal cords after reperfusion. Compared with controls, inhibition of miR-204 markedly decreased the motor deficit index scores at 6, 12, 24, and 48 hours after reperfusion; increased the number of viable motor neurons; and decreased the number of apoptotic neurons. 3-Methyladenine completely abolished enhancements of the LC3-II/LC3-I ratio and beclin-1 expression induced by antagomiR-204 and inhibited the protective effect on hind-limb motor function.

CONCLUSIONS

Inhibition of miR-204 exerts spinal cord protection against ischemia-reperfusion injury, possibly via promotion of autophagy and antiapoptotic effects.

miR‑204‑5p inhibits the occurrence and development of osteoarthritis by targeting Runx2

One of the hallmarks of osteoarthritis (OA) development is endochondral ossification, in which Runt-related transcription factor-2 (Runx2) is aberrantly expressed. Runx2 was previously identified to be regulated by microRNA-204-5p (miR-204-5p). The aim of the present study was to investigate the potential function of miR-204-5p regulating Runx2 during the development of OA and the underlying molecular mechanism. The expression levels of miR-204-5p and Runx2 were determined in tissue specimens. Rat OA models were established by transecting the anterior and posterior cruciate ligaments and removing the meniscus. Rats were treated with miR-204-5p agomir and miR-204-5p negative control (NC). All in vitro experiments were performed using rat primary chondrocytes and the SW-1353 human bone chondrosarcoma cell line. It was identified that the expression of miR-204-5p was significantly decreased, whereas Runx2 was significantly increased, in human OA tissues compared with in non-OA tissues, and levels were inversely associated with each other in primary chondrocytes and chondrosarcoma cells. Overexpression of miR-204-5p decreased the proliferation of chondrocytes and SW-1353 cells. Using a luciferase reporter assay, Runx2 was identified to be a direct target of miR-204-5p in chondrocytes and overexpressed miR-204-5p altered the expression of collagens II, X and matrix metalloproteinase (MMP)-1 and MMP-13 in primary chondrocytes and SW-1353 cells. Histological analysis revealed that miR-204-5p treatment ameliorated the OA-like phenotype that is reflected by assessment of cartilage thickness and Mankin's score. Runx2 expression was gradually increased as the rats increased in age. At 10 weeks of miR-204-5p agomir treatment, altered expression levels of collagens II and X, cartilage oligomeric matrix protein fragment, aggrecan, MMP-1 and MMP-13 were observed in the treatment group compared with the NC group. In conclusion, the results of the present study indicated that miR-204-5p decreases chondrocyte proliferation and ameliorates the OA-like phenotype in rats with surgically induced OA by targeting Runx2.

Prognostic value of microRNAs in colorectal cancer: a meta-analysis

Background

Numerous studies have shown that miRNA levels are closely related to the survival time of patients with colon, rectal, or colorectal cancer (CRC). However, the outcomes of different investigations have been inconsistent. Accordingly, a meta-analysis was conducted to study associations among the three types of cancers.

Materials and methods

Studies published in English that estimated the expression levels of miRNAs with survival curves in CRC were identified until May 20, 2017 by online searches in PubMed, Embase, Web of Science, and the Cochrane Library by two independent authors. Pooled HRs with 95% CIs were used to estimate the correlation between miRNA expression and overall survival.

Results

A total of 63 relevant articles regarding 13 different miRNAs, with 10,254 patients were ultimately included. CRC patients with high expression of blood miR141 (HR 2.52, 95% CI 1.68-3.77), tissue miR21 (HR 1.31, 95% CI 1.12-1.53), miR181a (HR 1.52, 95% CI 1.26-1.83), or miR224 (HR 2.12, 95% CI 1.04-4.34), or low expression of tissue miR126 (HR 1.55, 95% CI 1.24-1.93) had significantly poor overall survival (P<0.05).

Conclusion

In general, blood miR141 and tissue miR21, miR181a, miR224, and miR126 had significant prognostic value. Among these, blood miR141 and tissue miR224 were strong biomarkers of prognosis for CRC.

Targeted delivery of miRNA-204-5p by PEGylated polymer nanoparticles for colon cancer therapy

AIM

miRNAs have been recognized for their potential in cancer therapeutics, and multiple miRNAs were suggested to affect target genes expression. To overcome limitations of free synthetic miRNAs, such as easily degraded in biofluids and limited in cellular uptake, novel miRNAs delivery systems need to be developed.

MATERIALS & METHODS

Using surface-functionalizing technique, poly(D,L-lactide-co-glycolide)/poly(L-lactide)-block-poly(ethylene glycol)-folate polymer nanoparticle (PLGA/PLA-PEG-FA) loaded with miR-204-5p (FA-NPs-miR-204) was developed. The therapeutic efficacy of FA-NPs-miR-204 was evaluated in the Luc-HT-29 xenograft tumor model in vivo.

RESULTS

FA-NPs-miR-204 could be taken up by HT-29  and HCT-116 cells efficiently, resulting in significant inhibitory effect on cell proliferation and promotive effect on cell apoptosis. In vivo study showed that FA-NPs-miR-204 could exert tumor suppressive function in Luc-HT-29 xenograft model.

CONCLUSION

Our study demonstrates a convenient miRNA delivery system that targets tumor tissue and exerts tumor suppressive function, thus demonstrating a potential new therapeutic option for colon cancer.

The protective value of miR-204-5p for prognosis and its potential gene network in various malignancies: a comprehensive exploration based on RNA-seq high-throughput data and bioinformatics

Purpose

The prognostic role of miR-204-5p (previous ID: miR-204) is varied and inconclusive in diverse types of malignant neoplasm. Therefore, the purposes of the study comprehensively explore the overall prognostic role of miR-204-5p based on high-throughput microRNA sequencing data, and to investigate the potential role of miR-204-5p via bioinformatics approaches.

Materials and Methods

The data of microRNA sequencing and survival were downloaded from The Cancer Genome Atlas (TCGA), and the prognostic value of miR-204-5p was analyzed by using Kaplan-Meier and univariate cox regressions. Then a meta-analysis was conducted with all TCGA data and relevant studies collected from literature. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. The prospective molecular mechanism of miR-204-5p was also assessed at a functional level with Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-to-protein interactions (PPI) network.

Results

From TCGA data, the prognostic value of miR-204-5p obviously varied among 20 types of cancers. The pooled HR was 0.928 (95% CI: 0.774-1.113, P = 0.386, 6203 cases of malignancies). For the meta-analysis based on 15 studies from literature, the pooled HR was 0.420 (95% CI: 0.306-0.576, P < 0.001, 1783 cases of malignancies) for overall survival (OS). Furthermore, the combined HR from both TCGA and literature was 0.708 (95% CI: 0.600-0.834, P < 0.001, 7986 cases of malignancies). Subgroup analyses revealed that miR-204-5p could act as a prognostic marker in cancers of respiratory system and digestive system. Functional analysis was conducted on genes predicted as targets (n = 2057) after the overlay genes from six out of twelve software were extracted. Two significant KEGG pathways were enriched (hsa04360: Axon guidance and hsa04722: Neurotrophin signaling pathway). PPI network revealed some hub genes/proteins (CDC42, SOS1, PIK3R1, MAPK1, PLCG1, ESR1, MAPK11, and AR).

Conclusions

The current study demonstrates that over-expression of miR-204-5p could be a protective factor for a certain group of cancers. Clinically, the low miR-204-5p level could gain a predictive value for a poor survival in cancers of respiratory system and digestive system. The detailed molecular mechanisms of miR-204-5p remain to be verified.

Promising significance of the association of miR-204-5p expression with clinicopathological features of hepatocellular carcinoma

Decreased level of miR-204-5p has been documented in various malignancies. However, the expression and clinical significance of miR-204-5p in hepatocellular carcinoma has not been investigated. The aim of this study is to examine the relationship between miR-204-5p expression and clinicopathological features in hepatocellular carcinoma (HCC) as well as to predict the relevant signaling pathways. The miR-204-5p expression level was detected in HCC and in matched paraneoplastic liver from 95 formalin-fixed paraffin-embedded tissues by the real-time reverse transcription polymerized chain reaction (qRT-PCR). The association of miR-204-5p expression with clinicopathological features as well as the prognosis of HCC was examined. Public data portals including the Gene Expression Omnibus and The Cancer Genome Atlas were used to retrieve the HCC-related data in order to perform a comprehensive meta-analysis. Meanwhile, protein-protein interaction (PPI) and enrichment analyses were performed using predicted target genes. The relative expression of miR-204-5p was remarkably reduced in HCC than that in paraneoplastic hepatic tissues. In HCC, the miR-204-5p expression was downregulated in the metastasis, vasoinvasion, and advanced stage (III and IV) subgroups compared with their counterparts. Furthermore, the meta-analysis based on qRT-PCR data demonstrated that miR-204-5p was markedly downregulated in HCC with a standardized mean difference of -5.19 (P < .001). However, no significant association was observed between miR-204-5p and survival outcomes. The potential target genes of miR-204-5p were significantly enriched in several pathways which might be associated with HCC, such as "cell proliferation" from GO terms and "pathways in cancer" from the KEGG analysis. A PPI network of miR-204-5p potential target genes identified prospective core genes potentially involved in the regulation of HCC oncogenesis and progression. Our findings suggested that miR-204-5p might act as a tumor-suppressive gene in the tumorigenesis and progression of HCC via vital signaling pathways and that miR-204-5p could be regarded as a protective factor in HCC.

miR-10a and miR-204 as a Potential Prognostic Indicator in Low-Grade Gliomas

This study aimed to identify and characterize microRNAs (miRNAs) that are related to radiosensitivity in low-grade gliomas (LGGs). The miRNA expression levels in radiosensitive and radioresistant LGGs were compared using The Cancer Genome Atlas database, and differentially expressed miRNAs were identified using the EBSeq package. The miRNA target genes were predicted using Web databases. Fifteen miRNAs were differentially expressed between the groups, with miR-10a and miR-204 being related to overall survival (OS) of patients with LGG. Patients with upregulated miR-10a expression had a higher mortality rate and shorter OS time, whereas patients with downregulated miR-204 expression had a lower mortality rate and longer OS time. Two genes, HSP90AA1 and CREB5, were targets for both miRNAs. Thus, this study suggests that expression of miR-10a and miR-204 is significantly related to both radiosensitivity and the survival of patients with LGG. These miRNAs could therefore act as clinical biomarkers for LGG prognosis and diagnosis.

Altered mucosal expression of microRNAs in pediatric patients with inflammatory bowel disease

INTRODUCTION

MicroRNAs (miRs) came recently into focus as promising novel research targets offering new insights into the pathogenesis of inflammatory bowel diseases (IBD).

AIMS

The aim of our study was to identify a pediatric IBD (pIBD) characteristic miR profile serving as potential Crohn's disease (CD) and ulcerative colitis (UC) specific diagnostic pattern and to further analyze the related target genes.

METHODS

Small RNA sequencing was performed on inflamed and intact colonic biopsies of CD, and control patients. Selected miRs were further investigated by RT-PCR, complemented with an UC group, in order to address the differential diagnostic potential of miRs in the two IBD subtypes. To analyze network connection of differentially expressed miRs and their target genes MiRTarBase database and previous transcriptome sequencing data from pediatric patient groups were used.

RESULTS

Sequencing analysis identified 170 miRs with altered expression. RT-PCR analysis revealed altered expression of miR-31, -125a, -142-3p, and -146a discriminating between the inflamed mucosa of CD and UC. In the intact mucosa of CD patients the expression of miR-18a, -20a, -21, -31, -99a, -99b, -100, -125a, -126, -142-5p, -146a, -185, -204, -221, and -223 was elevated compared to the controls. The expression of miR-20a, -204 and -221 was elevated exclusively in the intact region of CD patients compared to the controls. Enrichment analysis identified main IBD-related functional groups.

CONCLUSIONS

We demonstrated a characteristic colonic miR pattern in pIBD that could facilitate deeper understanding of the pathomechanism of IBD and may serve as a diagnostic tool.

An exploratory study into the role of miR-204-5p in pregnancy-induced hypertension

The molecular mechanism that leads to pregnancy-induced hypertension (PIH), a pregnancy-specific syndrome, remains poorly understood. It has been suggested that microRNAs (miRNAs) may be potentially useful biomarkers for severe preeclampsia (PE), which is an important condition associated with PIH. The aim of the present study was to identify miR-204 by verifying differentially expressed serum miRNAs in patients with PIH during pregnancy compared with normal controls. Subsequently, the effects of miR-204 on proliferation and apoptosis of human choriocarcinoma (JAR) cells in hypoxic microenvironment were investigated. Previous studies indicated a number of miRNA candidates and the present study validated the expression of eight miRNAs in serum samples using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A higher expression of miR-204 was identified in patients with PIH. To assess the impact of miR-204 inhibition on hypoxic JAR cells function in vitro, cell proliferation was detected using a Cell Counting Kit-8 assay. The rate of apoptosis and cell cycle progression was then examined by flow cytometry. RT-qPCR confirmed that serum miR-204-5p is more highly expressed in patients with PIH. Further statistical analysis indicated that the survival ratio of JAR cells in hypoxic microenvironments was increased in the miR-204-5p inhibitor group. However, the miR-204-5p inhibitor protected hypoxic JAR cells from apoptosis. The analysis of cell-cycle status demonstrated that the percentage of cells in the G2/G1 phase was larger compared with the control group. The results of the present study suggest that low levels of miR-204-5p may increase cell proliferation and reduce cell apoptosis with cell cycle changes in vitro. Therefore, serum miR-204-5p may be used as a notable biomarker for the diagnosis, prevention and treatment of PIH.

Autophagy regulation and its role in gastric cancer and colorectal cancer

BACKGROUND

Autophagy is associated with the occurrence, development, cellular adaptation, progression, treatment and prognosis of gastric cancer (GC) and colorectal cancer (CRC). The effect of autophagy in these two cancers has attracted our attention.

OBJECTIVE

The aim of this study was to describe the functional and regulatory mechanisms associated with autophagy in GC and CRC.

METHODS

We reviewed recent publications describing the role of autophagy in GC and CRC, including the functional characteristics, clinical significance and regulatory mechanisms.

RESULTS

Autophagy plays context-dependent dual roles in the development and progression of GC and CRC. It can either promote tumor growth and cell survival or can contribute to tumor suppression and promote cell death. Both of these effects employ complex regulatory networks, such as those mediated by p53, PI3K/Akt/mTOR, Ras and microRNA. Among the cellular process associated with these pathways, autophagy is a potential target for anti-tumor therapy.

CONCLUSION

Autophagy is associated with both tumorigenic and protective effects in cancer. However, the role of autophagy in GC and CRC remains unclear. Although the translation of the basic science of autophagy into clinical practice is a long process, the modulation of autophagy as a potential therapeutic approach in GC and CRC merits further investigation.

Regulation of multidrug resistance by microRNAs in anti-cancer therapy

Multidrug resistance (MDR) remains a major clinical obstacle to successful cancer treatment. Although diverse mechanisms of MDR have been well elucidated, such as dysregulation of drugs transporters, defects of apoptosis and autophagy machinery, alterations of drug metabolism and drug targets, disrupti on of redox homeostasis, the exact mechanisms of MDR in a specific cancer patient and the cross-talk among these different mechanisms and how they are regulated are poorly understood. MicroRNAs (miRNAs) are a new class of small noncoding RNAs that could control the global activity of the cell by post-transcriptionally regulating a large variety of target genes and proteins expression. Accumulating evidence shows that miRNAs play a key regulatory role in MDR through modulating various drug resistant mechanisms mentioned above, thereby holding much promise for developing novel and more effective individualized therapies for cancer treatment. This review summarizes the various MDR mechanisms and mainly focuses on the role of miRNAs in regulating MDR in cancer treatment.

A new function for miRNAs as regulators of autophagy

Autophagy is a self-digestive process regulated by an intricate network of factors able either to ensure the prosurvival function of autophagy or to convert it in a death pathway. Recently, the involvement of miRNAs in the regulation of autophagy networks has been reported. This review will summarize the main features of these small noncoding endogenous RNAs, focusing on their relevance in cancer and finally addressing their impact on autophagy.

Deconvoluting the complexity of microRNAs in autophagy to improve potential cancer therapy

MicroRNAs (miRNAs) (small, non-coding RNAs ∼22 nucleotides [nt] in length), have been estimated to regulate in the region of 30% of human gene expression at the post-transcriptional and translational levels. They are also involved in a series of important cellular processes, such as autophagy. Autophagy is well-known to be an evolutionarily conserved lysosomal degradation process in which a cell degrades long-lived proteins and damaged organelles. Recent evidence has shown that miRNAs can function as either oncogenes or tumour-suppressive genes in human cancers. Also, they are well-characterized to be crucial in tumourigenesis, as either oncogenes or tumour suppressors, by regulating autophagy. However, discovering the intricate mechanism of miRNA-modulated autophagy remains in its infancy. Thus, in this review, we focus on summarizing the dual function of oncogenic or tumour-suppressive miRNAs in regulation of autophagy and their roles in carcinogenesis, thereby revealing the regulatory mechanism of miRNA-modulated autophagy in cancer, to shed light on more novel RNA therapeutic strategies in the future.

miRNA-204 suppresses human non-small cell lung cancer by targeting ATF2

MicroRNAs (miRNAs) play a critical role in cancer development and progression. Deregulated expression of miR-204 has been reported in several cancers, but the mechanism through which miR-204 modulates human non-small cell lung cancer (NSCLC) is largely unknown. In this study, we investigate the expression and functional role of miR-204 in human NSCLC tissues and cell lines. RNA isolation, qRT-PCR, MTT, colony formation assay, cell cycle assay, cell apoptosis assay, cell migration assay, and Western blot were performed. Statistical analysis was performed using SPSS 18.0 software and statistical significance was accepted at p value <0.05. miR-204 level was significantly reduced in NSCLC tissues as compared to that of non-neoplastic tissues. Transient over-expression of miR-204 by transfecting with miR-204 mimics suppressed NSCLC cell proliferation, migration, and induced apoptosis and G1 arrest, whereas inhibition of miR-204 showed the converse effects. Additionally, activating transcription factor 2 (ATF2), an important transcription factor, was demonstrated as a potential target gene of miR-204. Subsequent investigations found a negative correlation between miR-204 level and ATF2 expression in NSCLC tissue samples. Moreover, we observed that miR-204 expression inversely affected endogenous ATF2 expression at both mRNA and protein levels in vitro. Taken together, miR-204 may act as a tumor suppressor by directly targeting ATF2 in NSCLC.

MicroRNA-224: as a potential target for miR-based therapy of cancer

MicroRNAs (miRNAs) are small noncoding RNA molecules which regulate the target gene expression posttranscriptionally. Increasing studies have shown that microRNAs play important roles in multiple biological pathways. For instance, aberrant expression of microRNA-224 (miR-224) plays a vital role in tumor biology in various types of human cancer. Here, we aim to summarize the molecular mechanisms that lead to the overexpression of miR-224 in cancers, analyze the effect of miR-224 on tumor biology, and reveal the clinical significance of miR-224. MiR-224 regulates its targets by modulating messenger RNA (mRNA) stability and/or protein translation, and it would provide new insight into molecular targeting cancer treatment.

MicroRNA 211 expression is upregulated and associated with poor prognosis in colorectal cancer: a case-control study

Increasingly more evidence support the role of the microRNAs (miRNA) in tumorigenesis. The role of up/downregulation microRNA-211 (miR-211) during human tumorigenesis is still contentious and may exhibit tissue-specific regulatory manner, but the exhaustive mechanisms underlying its pro/anti-oncogenic effects remain to be unknown. Sixty-six patients that were diagnosed and operated with colorectal cancer (CRC) and sixty-five healthy cases that were age and sex compatible with them were included in our study. miRNA was isolated from the formalin-fixed paraffin-embedded (FFPE) tissues of all cases. The expression level of miR-211 in matched normal and tumor tissues of CRC group and healthy group was evaluated using a quantitative real-time RT-PCR (qRT-PCR). Based on the average miR-211 levels, two groups of low or high expression were formed in CRC group. Correlation of the patients' clinicopathological factors and survival was also analyzed. No statistically significant differences were found in miR-211 levels among tumorous and normal tissues of CRC patient group (P = 0.59). Also, no statistically significant correlation was determined between clinicopathological factors and miR-211 expression level in CRC group. However, miR-211 expression levels between the CRC group and the healthy group were determined to be of statistical significance (P < 0.0001). There were 33 (50 %) CRC patients that expressed low levels of miR-211 and 33 (50 %) CRC patients that expressed high levels of miR-211. A median survival between low levels of miR-211 group and high levels of miR-211 group was evaluated via Kaplan-Meier, and the difference was of statistical significance (P = 0.035). The univariate analysis of the factors that may affect survival indicated invasion depth (P = 0.063), lymphovascular invasion (P = 0.011), perineural invasion (P = 0.009), and miR-211 expression level (P = 0.041) presence to be effective. In the multivariate analysis of these factors with overall survival, only miR-211 expression level (P = 0.01) was effective on overall survival. Our results suggest for the first time that miR-211 expressed more in CRC patients than in healthy group could be a new prognostic biomarker in order to predict survival. Independent studies are needed to validate our findings in a larger series, as well as in cancer of different tissues.

Low expression of microRNA-204 (miR-204) is associated with poor clinical outcome of acute myeloid leukemia (AML) patients

BACKGROUND

Acute myeloid leukemia (AML) is a heterogeneous neoplasm of the bone marrow with poor prognosis. In clinical practice new prognostic factors are still needed. MicroRNAs (miRs), small endogenous noncoding RNAs, play an essential role in the development and progression of acute leukemia. The aim of the study was to evaluate miR-204 expression in patients with AML at diagnosis and after induction chemotherapy, in comparison to healthy controls. We also investigated, if miR-204 expression correlates with clinical features of AML patients.

METHODS

miR-204 expression has been analyzed using RT-PCR in 95 bone marrow specimens from newly diagnosed AML patients in comparison to 20 healthy subject.

RESULTS

We showed down-regulated miR-204 expression in AML patients, which was associated with shorter patients' survival. Higher expression of miR-204 in patients after induction therapy was correlated with complete remission achieving.

CONCLUSIONS

We showed low miR-204 expression in AML and found it to be an independent prognostic factor in this patient population.

Oncocers: ceRNA-mediated cross-talk by sponging miRNAs in oncogenic pathways

Competing endogenous RNAs (ceRNAs) are RNA transcripts which can communicate with each other by decreasing targeting concentration of micro-RNA (miRNA) with the derepression of other messenger RNAs (mRNAs) having the common miRNA response elements (MREs). Oncocers are ceRNAs taking crucial roles in oncogenic pathways processed in many types of cancer, and this study analyzes oncocer-mediated cross-talk by sponging microRNAs (miRNAs) in these pathways. While doing this, breast, liver, colon, prostate, gastric, lung, endometrium, thyroid and epithelial cancers and melanoma, rhabdomyosarcoma, glioblastoma, acute promyelocytic leukemia, retinoblastoma, and neuroblastoma were analyzed with respect to ceRNA-based carcinogenesis. This study defines, firstly, oncocers in the literature and contains all oncocer-related findings found up to now. Therefore, it will help to increase our comprehension about oncocer-mediated mechanisms. Via this study, a novel perspective would be produced to make clear cancer mechanisms and suggest novel approaches to regulate ceRNA networks via miRNA competition for cancer therapeutics. Graphical Abstract Multiple RNA transcripts have common MREs for the similar miRNA in their 3'-untranslated regions (3'-UTRs). Upregulation of ceRNAs rises the abundance of specific MREs and shifts the miRNA pool distribution, as a result, leading to the increased expression of target mRNA. The depot of genomic mutations and epigenetic alterations changing gene function and expression causes cancers. Herewith, genome-based somatic base-pair mutations, DNA copy number alterations, chromosomal translocation, also transcript fusions, alternative splicing are usually seen in cancer situations. Consequently, such cases causing changed UTR expression in transcripts influence the levels of MRE or present new MREs into the cells. Alterations in MREs of ceRNAs affect the capability of a specific mRNA transcript to attach or titrate miRNAs. As a result, the disturbed ceRNA network can lead to diseases and cancers. As a new term in RNA world, oncocers-the name for ceRNAs taking crucial roles in oncogenic pathways-are processed in many types of cancer, and oncocer-mediated cross-talk are analyzed by sponging miRNAs in these pathways.

Silencing clusterin gene transcription on effects of multidrug resistance reversing of human hepatoma HepG2/ADM cells

Abnormal clusterin (CLU) expression is associated with multidrug resistance (MDR) of hepatocellular carcinoma (HCC). In the present study, the CLU expression was analyzed in human hepatoma cells and chemoresistant counterpart HepG2/ADM cells. Compared with L02 cells, the overexpression of cellular CLU was identified in HepG2, HepG2/ADM, SMMC7721, Hep3B ,and PLC cells and relatively lower expression in Bel-7404, SNU-739, and MHCC97H cells. Specific short hairpin RNAs (shRNAs) to silence CLU gene transcription were designed, and the most effective sequences were screened. After the HepG2/ADM cells transfected with shRNA-1, the inhibition of CLU expression was 73.68 % at messenger RNA (mRNA) level by real-time quantitative RT-PCR with obvious enhancement in cell chemosensitivity, increasing apoptosis induced by doxorubicin using fluorescence kit, and Rh-123 retention qualified with flow cytometry. Knockdown CLU also significantly decreased the drug efflux pump activity through the depression of MDR1/P-glycoprotein (q = 11.739, P < 0.001). Moreover, silencing CLU led to downregulation of β-catenin (q = 13.544, P = 0.001), suggesting that downregulation of CLU might be a key point to reverse multidrug resistance of HepG2/ADM cells.