MicroRNA-493-5p promotes apoptosis and suppresses proliferation and invasion in liver cancer cells by targeting VAMP2

Prognostic signature construction of energy metabolism-related genes in pancreatic cancer

Pancreatic cancer is the 7th leading cause of cancer death worldwide, and its incidence and mortality rate have been on the rise in recent years in Western developed countries. The specificity of the disease and the lack of appropriate treatments have resulted in a 5-year overall survival rate of only 9%. In this study, we conducted a study based on the TCGA database and GEO database and analyzed using the energy metabolism gene set to establish a prognostic model with the least absolute shrinkage and selection operator to identify 7-genes prognostic signature, and the gene expression was verified by Real-time PCR. The model was validated using a risk score calculation, and the OS rates of the 7 genes were analyzed using one-way Cox regression. The prognostic relationship between vesicle-associated membrane protein 2 (VAMP2) and pancreatic cancer patients was analyzed by OS and progression-free survival, and the prognosis was found to be significantly worse in the high-expression group. A Nomogram showed that VAMP2 was an independent prognostic factor in pancreatic cancer. Gene set enrichment analysis showed that VAMP2 upregulation was enriched in pathways associated with immune response and that VAMP2 downregulation was enriched in metabolism-related pathways. The association of VAMP2 with immune cell infiltration was analyzed for the enrichment results, and VAMP2 was found to be positively associated with all 6 immune cells. The results of this study suggest that VAMP2 is an independent prognostic factor associated with energy metabolism in pancreatic cancer and may be involved in the immune response.

Integration of TE Induces Cancer Specific Alternative Splicing Events

Alternative splicing of messenger RNA (mRNA) precursors contributes to genetic diversity by generating structurally and functionally distinct transcripts. In a disease state, alternative splicing promotes incidence and development of several cancer types through regulation of cancer-related biological processes. Transposable elements (TEs), having the genetic ability to jump to other regions of the genome, can bring about alternative splicing events in cancer. TEs can integrate into the genome, mostly in the intronic regions, and induce cancer-specific alternative splicing by adjusting various mechanisms, such as exonization, providing splicing donor/acceptor sites, alternative regulatory sequences or stop codons, and driving exon disruption or epigenetic regulation. Moreover, TEs can produce microRNAs (miRNAs) that control the proportion of transcripts by repressing translation or stimulating the degradation of transcripts at the post-transcriptional level. Notably, TE insertion creates a cancer-friendly environment by controlling the overall process of gene expression before and after transcription in cancer cells. This review emphasizes the correlative interaction between alternative splicing by TE integration and cancer-associated biological processes, suggesting a macroscopic mechanism controlling alternative splicing by TE insertion in cancer.

Expression and Role of TRIM2 in Human Diseases

Tripartite motif (TRIM) protein family proteins contain more than 80 members in humans, and most of these proteins exhibit E3 ubiquitin ligase activity mediated through a RING finger domain. Their biological functions are very complex, and they perform diverse functions in cell evolution processes, such as intracellular signaling, development, apoptosis, protein quality control, innate immunity, autophagy, and carcinogenesis. Tripartite motif-containing protein 2 (TRIM2), a member of the TRIM superfamily, is an 81 kDa multidomain protein, also known as CMT2R or RNF86, located at 4q31.3. TRIM2 functions as an E3 ubiquitin ligase. Current studies have shown that TRIM2 can play roles in neuroprotection, neuronal rapid ischemic tolerance, antiviral responses, neurological diseases, etc. Moreover, based on some studies in tumors, TRIM2 regulates tumor proliferation, migration, invasion, apoptosis, and drug resistance through different mechanisms and plays a critical role in tumor occurrence and development. This review is aimed at providing a systematic and comprehensive summary of research on TRIM2 and at exploring the potential role of TRIM2 as a biomarker and therapeutic target in many kinds of human diseases.

The Preventive Effect of Cardiac Sympathetic Denervation Induced by 6-OHDA on Myocardial Ischemia-Reperfusion Injury: The Changes of lncRNA/circRNAs-miRNA-mRNA Network of the Upper Thoracic Spinal Cord in Rats

In this study, we investigated whether chemical 6-hydroxydopamine (6-OHDA) stimuli caused cardiac sympathetic denervation (SD), and we analyzed gene expression profiles to determine the changes in the lncRNA/circRNAs-miRNA-mRNA network in the affected spinal cord segments to identify putative target genes and molecular pathways in rats with myocardial ischemia–reperfusion injury (MIRI). Our results showed that cardiac sympathetic denervation induced by 6-OHDA alleviated MIRI. Compared with the ischemia reperfusion (IR, MIRI model) group, there were 148 upregulated and 51 downregulated mRNAs, 165 upregulated and 168 downregulated lncRNAs, 70 upregulated and 52 downregulated circRNAs, and 12 upregulated and 11 downregulated miRNAs in the upper thoracic spinal cord of the SD-IR group. Furthermore, we found that the differential genes related to cellular components were mainly enriched in extracellular and cortical cytoskeleton, and molecular functions were mainly enriched in chemokine activity. Pathway analysis showed that the differentially expressed genes were mainly related to the interaction of cytokines and cytokine receptors, sodium ion reabsorption, cysteine and methionine metabolism, mucoglycan biosynthesis, cGMP-PKG signaling pathway, and MAPK signaling pathway. In conclusion, the lncRNA/circRNAs-miRNA-mRNA networks in the upper thoracic spinal cord play an important role in the preventive effect of cardiac sympathetic denervation induced by 6-OHDA on MIRI, which offers new insights into the pathogenesis of MIRI and provides new targets for MIRI.

Integrated analysis of Solute carrier family-2 members reveals SLC2A4 as an independent favorable prognostic biomarker for breast cancer

Most of Solute carrier family-2 (SLC2) members play a key role of facilitative transporters, and glucose transporter (GLUT) proteins encoded by SLC2s can transport hexoses or polyols. However, the function and mechanism of SLC2s remain unclear in human cancers. Here, we explored the dysregulated expression, prognostic values, epigenetic, genetic alterations, and biomolecular network of SLC2s in human cancers. According to the data from public-omicsrepository, SLC2A4 (GLUT4) was found to be significantly downregulated in most cancers, and higher messenger RNA (mRNA) expression of SLC2A4 significantly associated with better prognosis of breast cancer (BRCA) patients. Moreover, DNA hypermethylation in the promoter of SLC2A4 may affect the regulation of its mRNA expression, and SLC2A4 was strongly correlated with pathways, including the translocation of SLC2A4 to the plasma membrane and PID INSULIN PATHWAY. In conclusion, these results provide insight into SLC2s in human cancers and suggest that SLC2A4 could be an unfavorable prognostic biomarker for the survival of BRCA patients.

Long noncoding RNA highly upregulated in liver cancer promotes the progression of hepatocellular carcinoma and attenuates the chemosensitivity of oxaliplatin by regulating miR-383-5p/vesicle-associated membrane protein-2 axis

We aimed to explore the function and underlying mechanism of highly upregulated in liver cancer (HULC; an long noncoding RNAs) in hepatocellular carcinoma (HCC) and chemosensitivity of oxaliplatin (Oxa). The expression of HULC, miR-383-5p, and vesicle-associated membrane protein-2 (VAMP2) was detected by quantitative real-time polymerase chain reaction. Western blot assay was applied for measuring the protein expression of cyclinD1, cleaved-caspase-3, light Chain 3 I/II, p62, and VAMP2. Cell viability and Oxa IC50 value were determined by Cell Counting Kit-8 assay. A colony formation assay was conducted to evaluate colony formation ability. Cell apoptosis was assessed by flow cytometry. The interaction between miR-383-5p and HULC or VAMP2 was predicted by bioinformatics analysis and verified by dual-luciferase reporter assay and RNA immunoprecipitation assay. The mice xenograft model was established to investigate the roles of HULC in vivo. HULC and VAMP2 were overexpressed whereas miR-383-5p was lowly expressed in HCC tissues. HULC overexpression promoted the progression of HCC cells and inhibited chemosensitivity of Oxa by increasing cell proliferation and protective autophagy and inhibiting apoptosis, whereas HULC silence presented opposite effects. Moreover, miR-383-5p was a direct target of HULC and miR-383-5p reversed the effects of HULC on the progression of HCC cells and chemosensitivity of Oxa. Besides, HULC acted as a molecular sponge of miR-383-5p to regulate VAMP2 expression. HULC promoted the progression of HCC and inhibited Oxa sensitivity by regulating miR-383-5p/VAMP2 axis, elucidating a novel regulatory mechanism for chemosensitivity of Oxa and providing a potential lncRNA-targeted therapy for HCC.

Association between SNAP25 and human glioblastoma multiform: a comprehensive bioinformatic analysis

Background: Glioblastoma multiforme (GBM) is a most common aggressive malignant brain tumor. In recent years, targeted therapy has been increasingly applied in GBM treatment.

Methods: In the present study, GSE22866 was downloaded from gene expression omnibus (GEO). The genomic and clinical data were obtained from TCGA. The differentially expressed genes (DEGs) were identified and functional analysis was performed using clusterprofiler. Then, the co-expression network for the DEGs was established using the “WGCNA” package. Next, the protein–protein interaction (PPI) was assessed using Search Tool for the Retrieval of Interacting Genes Database (STRING) and hub modules in Cytoscape were screened. The Venn diagram was plotted to showcase the overlapped hub DEGs in PPI network and TCGA. Univariate and multivariate Cox proportional hazards regression analyses were performed to predict the risk score of each patient. Validations of the hub gene were completed in other databases.

Results: Functional analysis of the DEGs verified the involvement of DEGs in growth factor binding and gated channel activity. Among the 10 GBM-related modules, the red one displayed the strongest tie with GBM. VAMP2 was filtered out as the most intimate protein. The PPI network and TCGA were comprehensively analyzed. Finally, SNAP25 was identified as a real hub gene positively correlated with GBM prognosis. The result was validated by GEPIA, ONCOMINE database and qRT-PCR.

Conclusions: SNAP25 might act as a GBM suppressor and a biomarker in GBM treatment.

Overexpression of Taspase 1 Predicts Poor Prognosis in Patients with Hepatocellular Carcinoma

Background

Taspase 1 (TASP1) is a highly conserved protease involved in site-specific proteolysis. Existing researches have revealed a link between TASP1 expression and carcinogenesis. However, limited data are available regarding the prognosis and functions of TASP1 in hepatocellular carcinoma (HCC).

Methods

Western Blotting and qRT-PCR were employed to evaluate the level of TASP1 in HCC cell lines and clinical specimens. TASP1 expression was further calculated in clinical specimens by immunohistochemistry and the mRNA level of TASP1 in HCC was analyzed using Oncomine and UALCAN databases. The TASP1 promoter methylation modification was shown via MEXPRESS and UALCAN. The association between TASP1 expression and postoperative prognosis was evaluated using Kaplan–Meier and Cox regression analysis in clinical patients. The effect of TASP1 on HCC prognosis was analyzed via Kaplan-Meier plotter, GEPIA and UALCAN. Additionally, the regulators, kinases, miRNA and transcription factor targets of TASP1 were identified using LinkedOmics. Moreover, cBioPortal was used to detect the genetic alteration of TASP1. Finally, TIMER was utilized to assess the relation between TASP1 and the immune cell infiltration, whereas the correlation of TASP1 with three immune factors was detected through TISIDB.

Results

TASP1 expression was increased in HCC cell lines and HCC tissues. CNV and DNA methylation of TASP1 were changed. Survival analysis revealed that high TASP1 expression was correlated with overall survival (OS). Functional network analysis about TASP1 in HCC showed that the double-strand break repair, peptidyl-threonine modification, spindle organization, peptidyl-lysine modification and microtubule-based movement were modulated. Furthermore, TASP1 expression revealed puissant relation to the infiltration of immune cells and three immune factors in HCC.

Conclusion

These data indicate that TASP1 may act as a potential prognostic marker in HCC and regulate HCC via multiple mechanisms.

Silencing of Long Non-Coding RNA FGD5-AS1 Inhibits the Progression of Non-Small Cell Lung Cancer by Regulating the miR-493-5p/DDX5 Axis

Background:

Long non-coding RNA FGD5 antisense RNA 1 (FGD5-AS1), identified to be a carcinogenic lncRNA, exhibits a regulatory role in some malignancies including non-small cell lung cancer (NSCLC). The aim of the present research is to decipher the function and underlying mechanism of FGD5-AS1 in progression of NSCLC.

Methods:

Expression of FGD5-AS1, miR-493-5p and DEAD-box protein 5 (DDX5) in NSCLC tissues and cells was quantified utilizing qRT-PCR. Cell proliferation was assessed by CCK-8 method. Scratch healing test and Transwell assay were used for assaying cell migration and invasion. Expressions of DDX5 and epithelial-mesenchymal transition (EMT)-related proteins were examined by Western blot. Additionally, targeting relationships between FGD5-AS1 and miR-493-5p, miR-493-5p and DDX5 were verified by dual-luciferase reporter gene assay.

Results:

Expression of FGD5-AS1 in NSCLC tissues and cell lines was up-regulated. Expression of FGD5-AS1 was in association with enlarged tumor size and lymph node metastasis of the patients. Knockdown of FGD5-AS1 led to the inhibition of proliferation, migration, invasion and EMT of NSCLC cells. FGD5-AS1 directly targeted miR-493-5p, while DDX5 was the target of miR-493-5p in NSCLC cells. Additionally, FGD5-AS1 could positively regulate the expression of DDX5 via suppressing miR-493-5p.

Conclusion:

FGD5-AS1 facilitates the proliferation, migration, invasion and EMT of NSCLC cells by sponging miR-493-5p and up-regulating DDX5.

Lung cancer‑associated transcript 1 facilitates tumorigenesis in laryngeal squamous cell carcinoma through the targeted inhibition of miR‑493

Long non-coding RNAs (lncRNAs) serve important roles in the tumorigenesis of a diverse range of cancer types. The lung cancer-associated transcript 1 (LUCAT1), has been reported to promote the proliferation, migration and invasion of oral squamous cell carcinoma cells. However, the exact role of LUCAT1 in laryngeal squamous cell carcinoma (LSCC) remains to fully understood. The present study aimed to interrogate the role and modulatory mechanism of LUCAT1 in LSCC. Reverse transcription-quantitative PCR and western blotting were used to investigate the expression of LUCAT1 and miR-493, as well as the protein expression of cyclin-dependent kinase 2, cyclin E1, p21, matrix metalloproteinase (MMP)2, MMP9, vascular endothelial growth factor-C, Bcl-2, Bax, cleaved caspase-3 and procaspase-3. Cell Counting Kit-8, flow cytometry, wound healing and Transwell assays were performed to analyze the proliferation, cell cycle, apoptosis levels, and the migratory and invasive abilities, respectively, of the LSCC AMC-HN-8 cell line. In addition, dual-luciferase reporter and ribonucleoprotein immunoprecipitation assays were used to investigate the binding between LUCAT1 and microRNA (miR)-493. The results of the present study revealed that the expression levels of LUCAT1 were upregulated in AMC-HN-8 cells. The genetic knockdown of LUCAT1 expression levels significantly suppressed the cell proliferation, alongside downregulating the expression levels of CDK2 and cyclin E1 and upregulating p21 expression levels. In addition, the knockdown of LUCAT1 inhibited cell migration and invasion, as demonstrated using the wound healing and Transwell assays, respectively. Moreover, LUCAT1 knockdown promoted cell apoptosis and upregulated the expression levels of Bax and cleaved caspase-3, whilst downregulating the expression levels of Bcl-2. Furthermore, LUCAT1 was discovered to directly bind to and inhibit the well-known tumor suppressor, miR-493. Notably, the specific inhibition of miR-493 partly blocked the anticancer effects of LUCAT1 knockdown in AMC-HN-8 cells. In conclusion, these results suggested that LUCAT1 may facilitate tumorigenesis in LSCC through the targeted inhibition of miR-493, which provides evidence for a novel target for the treatment of LSCC.

Creation of a Prognostic Risk Prediction Model for Lung Adenocarcinoma Based on Gene Expression, Methylation, and Clinical Characteristics

Background

This study aimed to identify important marker genes in lung adenocarcinoma (LACC) and establish a prognostic risk model to predict the risk of LACC in patients.

Material/Methods

Gene expression and methylation profiles for LACC and clinical information about cases were downloaded from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases, respectively. Differentially expressed genes (DEGs) and differentially methylated genes (DMGs) between cancer and control groups were selected through meta-analysis. Pearson coefficient correlation analysis was performed to identify intersections between DEGs and DMGs and a functional analysis was performed on the genes that were correlated. Marker genes and clinical factors significantly related to prognosis were identified using univariate and multivariate Cox regression analyses. Risk prediction models were then created based on the marker genes and clinical factors.

Results

In total, 1975 DEGs and 2095 DMGs were identified. After comparison, 16 prognosis-related genes (EFNB2, TSPAN7, INPP5A, VAMP2, CALML5, SNAI2, RHOBTB1, CKB, ATF7IP2, RIMS2, RCBTB2, YBX1, RAB27B, NFATC1, TCEAL4, and SLC16A3) were selected from 265 overlapping genes. Four clinical factors (pathologic N [node], pathologic T [tumor], pathologic stage, and new tumor) were associated with prognosis. The prognostic risk prediction models were constructed and validated with other independent datasets.

Conclusions

An integrated model that combines clinical factors and gene markers is useful for predicting risk of LACC in patients. The 16 genes that were identified, including EFNB2, TSPAN7, INPP5A, VAMP2, and CALML5, may serve as novel biomarkers for diagnosis of LACC and prediction of disease prognosis.

Efficacy of abiraterone combined with flutamide on prostate cancer patients and its effect on serum miR-493-5p and miR-195-5p

Efficacy of abiraterone combined with flutamide on patients with prostate cancer (PCa) and its effect on levels of miR-493-5p and miR-195-5p contained in serum were investigated. The medical records of 146 PCa patients admitted to Longhua Hospital Shanghai University of Traditional Chinese Medicine from January 2011 to December 2013 were selected. Eighty-four patients were treated with abiraterone combined with flutamide as a study group, 62 patients were treated with abiraterone alone as a control group. The curative effect, adverse reactions, quality of life and five-year overall survival (OS) of the two groups were compared. The serum prostate-specific antigen (PSA) level was measured by radioimmunoassay at 3 days (T1) before treatment, 1 month (T2), 2 months (T3), and 6 months (T4) after treatment, and the relative expression of miR-493-5p and miR-195-5p in serum were detected by qRT-PCR. The total effective rate of the study group was significantly higher than that of the control group (P<0.05). The total incidence of toxic and side effects in the study group was significantly lower than that in the control group (P<0.05). The improvement rate of quality of life in the study group was significantly higher than that in the control group (P<0.05). OS in the study group was significantly higher than that in the control group at 5 years (P<0.05). There was no significant difference in serum PSA level between the two groups at T1 (P>0.05); there was no significant difference in the relative expression of miR-493-5p and miR-195-5p between the two groups at T1 (P>0.05). In conclusion, abiraterone combined with flutamide has better curative effect and lower incidence of adverse reactions in patients with metastatic castration-resistant PCa (CRPC) than abiraterone alone, and can increase the expression levels of miR-493-5p and miR-195-5p in patient serum.

miR-505 inhibits proliferation of osteosarcoma via HMGB1

Osteosarcoma is a malignant bone tumor, and clinically detectable metastases can be detected in ~ 15–20% of patients when they seek medical advice; patients with metastatic disease have extremely poor prognosis. Here, we examined the involvement of the microRNA miR‐505 in osteosarcoma. Eighty‐four patients seeking treatment for osteosarcoma were included in the study group (SG), and 63 healthy subjects were allocated to the control group (CG). Normal human bone cells MG‐63 and U20S cells were transfected with miR‐505 mimics, miR‐NC, HMGB1 RNA for targeted inhibition (si‐HMGB1), and si‐NC to examine the effects on HMGB1 expression. Cell proliferation, invasion, and apoptosis were measured using CCK‐8, scratch assays, and flow cytometry (FCM), respectively, and the relationship between miR‐505 and HMGB1 was determined using the dual‐luciferase reporter assay. In patient tissues and serum, miR‐505 was expressed at a low level, and HMGB1 was expressed at a high level, with an area under curve of > 0.9. Furthermore, the expression of miR‐505 and HMGB1 in tissues had a positive association with that in the serum, whereas the expression of miR‐505 had a negative association with that of HMGB1 in tissues only. Overexpression of miR‐505 and silencing of HMGB1 suppressed the proliferation, migration, and invasion of osteosarcoma cells and increased the rate of apoptosis, whereas the co‐transfected miR‐505 mimics + si‐HMGB1 demonstrated a more significant inhibitory effect on the proliferation and invasion of osteosarcoma cells and a higher apoptosis rate. miR‐505 may inhibit the proliferation and invasion and promote apoptosis of osteosarcoma cells by targeting and suppressing HMGB1.

LncRNA BCAR4 promotes liver cancer progression by upregulating ANAPC11 expression through sponging miR‑1261

Liver cancer is a malignant tumor that occurs in the liver and can be divided into primary and secondary liver cancer. Long non-coding RNA (lncRNA) breast cancer anti-estrogen resistance 4 (BCAR4) has been demonstrated to promote the development of various types of cancer. However, the function of lncRNA BCAR4 in liver cancer remains unclear. In the present study, the expression of lncRNA BCAR4 was notably elevated in liver cancer compared with adjacent non-tumor tissues. Functional in vitro assays demonstrated that knockdown of lncRNA BCAR4 inhibited the proliferation, migration and invasion of Huh-7 cells. In addition, lncRNA BCAR4 was demonstrated to directly bind to microRNA (miR)-1261, and miR-1261 expression negatively correlated with the expression of lncRNA BCAR4. Through bioinformatics analysis, lncRNA BCAR4 was predicted to target anaphase-promoting complex subunit 11 (ANAPC11) through miR-1261. In addition, the results demonstrated that lncRNA BCAR4 increased the expression of ANAPC11 by inhibiting miR-1261 expression. Consistently, overexpression of ANAPC11 or inhibition of miR-1261 significantly rescued liver cancer cell proliferation induced by knockdown of lncRNA BCAR4. Collectively, the results of the present study demonstrated that lncRNA BCAR4 may promote liver cancer development by directly binding to miR-1261 and targeting ANAPC11.

MicroRNA-493-5p-mediated repression of the MYCN oncogene inhibits hepatic cancer cell growth and invasion

Primary hepatic tumors mainly include hepatocellular carcinoma (HCC), which is one of the most frequent causes of cancer‐related deaths worldwide. Thus far, HCC prognosis has remained extremely poor given the lack of effective treatments. Numerous studies have described the roles played by microRNAs (miRNAs) in cancer progression and the potential of these small noncoding RNAs for diagnostic or therapeutic applications. The current consensus supports the idea that direct repression of a wide range of oncogenes by a single key miRNA could critically affect the malignant properties of cancer cells in a synergistic manner. In this study, we aimed to investigate the oncogenes controlled by miR‐493‐5p, a major tumor suppressor miRNA that inactivates miR‐483‐3p oncomir in hepatic cancer cells. Using global gene expression analysis, we highlighted a set of candidate genes potentially regulated by miR‐493‐5p. In particular, the canonical MYCN protooncogene (MYCN) appeared to be an attractive target of miR‐493‐5p given its significant inhibition through 3′‐UTR targeting in miR‐493‐5p‐rescued HCC cells. We showed that MYCN was overexpressed in liver cancer cell lines and clinical samples from HCC patients. Notably, MYCN expression levels were inversely correlated with miR‐493‐5p in tumor tissues. We confirmed that MYCN knockdown mimicked the anticancer effect of miR‐493‐5p by inhibiting HCC cell growth and invasion, whereas MYCN rescue hindered miR‐493‐5p activity. In summary, miR‐493‐5p is a pivotal miRNA that modulates various oncogenes after its reexpression in liver cancer cells, suggesting that tumor suppressor miRNAs with a large spectrum of action could provide valuable tools for miRNA replacement therapies.

Human CAP cells represent a novel source for functional, miRNA-loaded exosome production

Exosomes represent a promising delivery tool for nucleic acid-based pharmaceuticals. They are highly suitable for transporting therapeutic miRNAs to tumor cells, due to their natural membrane components. Further, exosomes are capable of effectively protecting nucleic acids against ribonucleases and enable the delivery of their content through cell membranes. However, no suitable production host for miRNA containing exosomes of non-tumorigenic origin has yet been identified. In this study we engineered an immortalised human amniocyte cell line (CAP^® cells), whose exosomes were enriched and characterised. The cell line modifications not only enabled the production of GFP-labelled but also pro-apoptotic miRNA containing exosomes without negative influence on host cell growth. Furthermore, we demonstrated that pro-apoptotic miRNA containing CAP exosomes are taken up by ovarian cancer cells. Strikingly, delivery of functional exosomal miRNA led to downregulation of several reported target genes in the treated tumor cells. In summary, we revealed CAP cells of non-tumorigenic origin as a novel and efficient exosome production host with the potential to produce functional miRNA-loaded exosomes.

MEG3-derived miR-493-5p overcomes the oncogenic feature of IGF2-miR-483 loss of imprinting in hepatic cancer cells

Numerous studies have described the critical role played by microRNAs (miRNAs) in cancer progression and the potential of these small non-coding RNAs for diagnostic or therapeutic applications. However, the mechanisms responsible for the altered expression of miRNAs in malignant cells remain poorly understood. Herein, via epigenetic unmasking, we identified a group of miRNAs located in the imprinted delta like non-canonical Notch ligand 1 (DLK1)-maternally expressed 3 (MEG3) locus that were repressed in hepatic tumor cells. Notably, miR-493-5p epigenetic silencing was correlated with hypermethylation of the MEG3 differentially regulated region (DMR) in liver cancer cell lines and tumor tissues from patients. Experimental rescue of miR-493-5p promoted an anti-cancer response by hindering hepatocellular carcinoma (HCC) cell growth in vitro and tumor progression in vivo. We found that miR-493-5p mediated part of its tumor-suppressor activity by abrogating overexpression of insulin-like growth factor 2 (IGF2) and the IGF2-derived intronic oncomir miR-483-3p in HCC cells characterized by IGF2 loss of imprinting (LOI). In summary, this study describes an unknown miRNA-dependent regulatory mechanism between two distinct imprinted loci and a possible therapeutic window for liver cancer patients exhibiting IGF2-miR-483 LOI and amplification.

MicroRNA-197-3p acts as a prognostic marker and inhibits cell invasion in hepatocellular carcinoma

MicroRNAs (miRNAs) serve an important regulatory role in carcinogenesis and cancer progression. Aberrant expression of miR-197-3p has been reported in various human malignancies. However, the role of miR-197-3p in the progression and prognosis of hepatocellular carcinoma (HCC) remains unknown. The present study demonstrated that miR-197-3p was downregulated in HCC tissues and that the low level of miR-197-3p expression in HCC tumours correlated with aggressive clinicopathological characteristics; thus, miR-197-3p may serve as a predictor for poor prognosis in patients with HCC. Additionally, miR-197-3p markedly inhibited the metastasis of HCC cells in vitro and in vivo. Bioinformatics analysis further identified zinc finger protein interacted with K protein 1 (ZIK1) as a novel target of miR-197-3p in HCC cells. These findings suggest that miR-197-3p may regulate the survival of HCC cells, partially through the downregulation of ZIK1. Therefore, the miR-197-3p/ZIK1 axis may serve as a novel therapeutic target in patients with HCC.

Upregulation of microRNA 344a-3p is involved in curcumin induced apoptosis in RT4 schwannoma cells

Background

Schwannoma arising from peripheral nervous sheaths is a benign tumor.

Methods

To evaluate cell cytotoxicity, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction and terminal deoxynucleotidyltransferase UTP nick-end labeling (TUNEL) assays were used. A microRNA (miRNA) array was used to identify the miRNAs involved in curcumin-induced apoptosis. To examine miRNA expression, quantitative RT-PCR was used.

Results

In this study, curcumin exerted cellular cytotoxicity against RT4 schwannoma cells, with an increase in TUNEL-positive cells. Curcumin also activated the expression of apoptotic proteins, such as polyADP ribose polymerase, caspase-3, and caspase-9. The miRNA array revealed that seven miRNAs (miRNA 350, miRNA 17-2-3p, let 7e-3p, miRNA1224, miRNA 466b-1-3p, miRNA 18a-5p, and miRNA 322-5p) were downregulated following treatment with both 10 and 20 μM curcumin in RT4 cells, while four miRNAs (miRNA122-5p, miRNA 3473, miRNA182, and miRNA344a-3p) were upregulated. Interestingly, transfection with a miRNA 344a-3p mimic downregulated the mRNA expression of Bcl2 and upregulated that of Bax, Curcumin treatment in RT 4 cells also reduced the mRNA expression of Bcl2 and enhanced expression of Bax, Overexpression of miRNA344a-3p mimic combined with curcumin treatment activated the expression of apoptotic proteins, including procaspase-9 and cleaved caspase-3 while inhibition of miRNA 344a-3p using miR344a-3p inhibitor repressed cleaved caspase-3 and -9 in curcumin treated RT-4 cells compared to control.

Conclusions

Our findings demonstrate that curcumin induces apoptosis in schwannoma cells via miRNA 344a-3p. Thus, curcumin may serve as a potent therapeutic agent for the treatment of schwannoma.

miR‑3666 suppresses cellular proliferation and invasion in colorectal cancer by targeting SATB2

MicroRNA-3666 (miR-3666) acts as a tumor suppressor in cervical cancer, non-small cell lung cancer and thyroid carcinoma; however, the function of miR-3666 in colorectal cancer (CRC) remains largely unknown. In the present study, was demonstrated that miR-3666 was significantly downregulated in CRC tissues compared with in adjacent normal tissues by reverse transcription-quantitative polymerase chain reaction. Additionally, miR-3666 may serve as a prognostic biomarker for patients with CRC. Via functional experiments, the present study reported that miR-3666 overexpression significantly inhibited the proliferation, migration and invasion of CRC cells as determined by Cell Counting Kit-8 and Transwell assays, and vice versa. In addition, miR-3666 was reported to directly target special AT-rich sequence binding protein 2 (SATB2) in CRC cells; overexpression of miR-3666 significantly suppressed the expression of SATB2 in CRC cells as determined by western blotting. Furthermore, an inverse correlation was observed between the expression levels of miR-3666 and SATB2 in CRC tissues. Restoration of SATB1 expression significantly reversed the effects of miR-3666 mimic on CRC cells. In summary, the results of the present study indicated that miR-3666 may serve as a tumor suppressor in CRC by targeting SATB2.