miR‑494 is an independent prognostic factor and promotes cell migration and invasion in colorectal cancer by directly targeting PTEN

Dysregulated miRNAs in a canine model of haemangiosarcoma metastatic to the brain

Haemangiosarcoma is a highly metastatic and lethal cancer of blood vessel-forming cells that commonly spreads to the brain in both humans and dogs. Dysregulations in phosphatase and tensin (PTEN) homologue have been identified in various types of cancers, including haemangiosarcoma. MicroRNAs (miRNAs) are short noncoding single-stranded RNA molecules that play a crucial role in regulating the gene expression. Some miRNAs can function as oncogenes or tumour suppressors, influencing important processes in cancer, such as angiogenesis. This study aimed to investigate whether miRNAs targeting PTEN were disrupted in canine haemangiosarcoma and its corresponding brain metastases (BM). The expression levels of miRNA-10b, miRNA-19b, miRNA-21, miRNA-141 and miRNA-494 were assessed in samples of primary canine cardiac haemangiosarcomas and their matched BM. Furthermore, the miRNA profile of the tumours was compared to samples of adjacent non-cancerous tissue and healthy control tissues. In primary cardiac haemangiosarcoma, miRNA-10b showed a significant increase in expression, while miRNA-494 and miRNA-141 exhibited downregulation. Moreover, the overexpression of miRNA-10b was retained in metastatic brain lesions. Healthy tissues demonstrated significantly different expression patterns compared to cancerous tissues. In particular, the expression of miRNA-10b was nearly undetectable in both control brain tissue and perimetastatic cerebral tissue. These findings can provide a rationale for the development of miRNA-based therapeutic strategies, aimed at selectively treating haemangiosarcoma.

Novel insights on perils and promises of miRNA in understanding colon cancer metastasis and progression

Colorectal cancer (CRC) is the third highest frequent malignancy and ultimate critical source of cancer-associated mortality around the world. Regardless of latest advances in molecular and surgical targeted medicines that have increased remedial effects in CRC patients, the 5-year mortality rate for CRC patients remains dismally low. Evidence suggests that microRNAs (miRNAs) execute an essential part in the development and spread of CRC. The miRNAs are a type of short non-coding RNA that exhibited to control the appearance of tumor suppressor genes and oncogenes. miRNA expression profiling is already being utilized in clinical practice as analytical and prognostic biomarkers to evaluate cancer patients' tumor genesis, advancement, and counteraction to drugs. By modulating their target genes, dysregulated miRNAs are linked to malignant characteristics (e.g., improved proliferative and invasive capabilities, cell cycle aberration, evasion of apoptosis, and promotion of angiogenesis). This review presents an updated summary of circulatory miRNAs, tumor-suppressive and oncogenic miRNAs, and the potential reasons for dysregulated miRNAs in CRC. Further we will explore the critical role of miRNAs in CRC drug resistance.

Molecular Classification of Colorectal Cancer by microRNA Profiling: Correlation with the Consensus Molecular Subtypes (CMS) and Validation of miR-30b Targets

Colorectal cancer consensus molecular subtypes (CMSs) are widely accepted and constitutes the basis for patient stratification to improve clinical practice. We aimed to find whether miRNAs could reproduce molecular subtypes, and to identify miRNA targets associated to the High-stroma/CMS4 subtype. The expression of 939 miRNAs was analyzed in tumors classified in CMS. TALASSO was used to find gene-miRNA interactions. A miR-mRNA regulatory network was constructed using Cytoscape. Candidate gene-miR interactions were validated in 293T cells. Hierarchical-Clustering identified three miRNA tumor subtypes (miR-LS; miR-MI; and miR-HS) which were significantly associated (p < 0.001) to the reported mRNA subtypes. miR-LS correlated with the low-stroma/CMS2; miR-MI with the mucinous-MSI/CMS1 and miR-HS with high-stroma/CMS4. MicroRNA tumor subtypes and association to CMSs were validated with TCGA datasets. TALASSO identified 1462 interactions (p < 0.05) out of 21,615 found between 176 miRs and 788 genes. Based on the regulatory network, 88 miR-mRNA interactions were selected as candidates. This network was functionally validated for the pair miR-30b/SLC6A6. We found that miR-30b overexpression silenced 3′-UTR-SLC6A6-driven luciferase expression in 293T-cells; mutation of the target sequence in the 3′-UTR-SLC6A6 prevented the miR-30b inhibitory effect. In conclusion CRC subtype classification using a miR-signature might facilitate a real-time analysis of the disease course and treatment response.

Cooperative miRNA-dependent PTEN regulation drives resistance to BTK inhibition in B-cell lymphoid malignancies

Aberrant microRNA (miR) expression plays an important role in pathogenesis of different types of cancers, including B-cell lymphoid malignancies and in the development of chemo-sensitivity or -resistance in chronic lymphocytic leukemia (CLL) as well as diffuse large B-cell lymphoma (DLBCL). Ibrutinib is a first-in class, oral, covalent Bruton's tyrosine kinase (BTK) inhibitor (BTKi) that has shown impressive clinical activity, yet many ibrutinib-treated patients relapse or develop resistance over time. We have reported that acquired resistance to ibrutinib is associated with downregulation of tumor suppressor protein PTEN and activation of the PI3K/AKT pathway. Yet how PTEN mediates chemoresistance in B-cell malignancies is not clear. We now show that the BTKi ibrutinib and a second-generation compound, acalabrutinib downregulate miRNAs located in the 14q32 miRNA cluster region, including miR-494, miR-495, and miR-543. BTKi-resistant CLL and DLBCL cells had striking overexpression of miR-494, miR-495, miR-543, and reduced PTEN expression, indicating further regulation of the PI3K/AKT/mTOR pathway in acquired BTKi resistance. Additionally, unlike ibrutinib-sensitive CLL patient samples, those with resistance to ibrutinib treatment, demonstrated upregulation of 14q32 cluster miRNAs, including miR-494, miR-495, and miR-543 and decreased pten mRNA expression. Luciferase reporter gene assay showed that miR-494 directly targeted and suppressed PTEN expression by recognizing two conserved binding sites in the PTEN 3'-UTR, and subsequently activated AKT^Ser473. Importantly, overexpression of a miR-494 mimic abrogated both PTEN mRNA and protein levels, further indicating regulation of apoptosis by PTEN/AKT/mTOR. Conversely, overexpression of a miR-494 inhibitor in BTKi-resistant cells restored PTEN mRNA and protein levels, thereby sensitizing cells to BTKi-induced apoptosis. Inhibition of miR-494 and miR-495 sensitized cells by cooperative targeting of pten, with additional miRNAs in the 14q32 cluster that target pten able to contribute to its regulation. Therefore, targeting 14q32 cluster miRNAs may have therapeutic value in acquired BTK-resistant patients via regulation of the PTEN/AKT/mTOR signaling axis.

Histone Modifier Differentially Regulates Gene Expression and Unravels Survival Role of MicroRNA-494 in Jurkat Leukemia

BACKGROUND

Although the protein-coding genes are subject to histone hyperacetylation-mediated regulation, it is unclear whether microRNAs are similarly regulated in the T cell leukemia Jurkat.

OBJECTIVE

To determine whether treatment with the histone modifier Trichostatin A could concurrently alter the expression profiles of microRNAs and protein-coding genes.

METHODS

Changes in histone hyperacetylation and viability in response to drug treatment were analyzed, respectively, using western blotting and flow cytometry. Paired global expression profiling of microRNAs and coding genes was performed and highly regulated genes validated by qRT-PCR. The interrelationships between the drug-induced miR-494 upregulation, the expression of putative target genes, and T cell receptor-mediated apoptosis were evaluated using qRT-PCR, flow cytometry, and western blotting following lipid-mediated transfection with specific anti-microRNA inhibitors.

RESULTS

Treatment of Jurkat cells with Trichostatin A resulted in histone hyperacetylation and apoptosis. Global expression profiling indicated prominent upregulation of miR-494 in contrast to differential regulation of many protein-coding and non-coding genes validated by qRT-PCR. Although transfection with synthetic anti-miR-494 inhibitors failed to block drug-induced apoptosis or miR-494 upregulation, it induced the transcriptional repression of the PVRIG gene. Surprisingly, miR-494 inhibition in conjunction with low doses of Trichostatin A enhanced the weak T cell receptor-mediated apoptosis, indicating a subtle pro-survival role of miR-494. Interestingly, this pro-survival effect was overwhelmed by mitogen-mediated T cell activation and higher drug doses, which mediated caspase-dependent apoptosis.

CONCLUSION

Our results unravel a pro-survival function of miR-494 and its putative interaction with the PVRIG gene and the apoptotic machinery in Jurkat cells.

Targeting c-Jun in A549 Cancer Cells Exhibits Antiangiogenic Activity In Vitro and In Vivo Through Exosome/miRNA-494-3p/PTEN Signal Pathway

The oncogene c-Jun is activated by Jun N-terminal kinase (JNK). Exosomes are nanometer-sized membrane vesicles released from a variety of cell types, and are essential for cell-to-cell communication. By using specific JNK inhibitor SP600125 or CRISPR/Cas9 to delete c-Jun, we found that exosomes from SP600125-treated A549 cancer cells (Exo-SP) or from c-Jun-KO-A549 cells (Exo-c-Jun-KO) dramatically inhibited tube formation of HUVECs. And the miR-494 levels in SP600125 treated or c-Jun-KO A549 cells, Exo-SP or Exo-c-Jun-KO, and HUVECs treated with Exo-SP or Exo-c-Jun-KO were significantly decreased. Meanwhile, Exo-SP and Exo-c-Jun-KO enhanced expression of phosphatase and tensin homolog deleted on chromosome ten (PTEN). Addition of miR-494 agomir in Exo-c-Jun-KO treated HUVECs inhibited PTEN expression and promoted tube formation, suggesting the target of miR-494 might be PTEN in HUVECs. Moreover, A549 tumor xenograft model and Matrigel plug assay demonstrated that Exo-c-Jun-KO attenuated tumor growth and angiogenesis through reducing miR-494. Taken together, inhibition of c-Jun in A549 cancer cells exhibited antiangiogenic activity in vitro and in vivo through exosome/miRNA-494-3p/PTEN signal pathway.

Gene expression patterns associated with tumor-infiltrating CD4+ and CD8+ T cells in invasive breast carcinomas

BACKGROUND

Breast carcinoma is one of the most common tumors in women. The immune microenvironment, especially T cell infiltration, is related to the occurrence and prognosis of breast carcinoma.

OBJECTIVE

This study investigated the gene expression patterns associated with tumor-infiltrating CD4+ and CD8+ T cells in invasive breast carcinomas.

METHODS

The gene expression data and corresponding clinical phenotype data from the Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA) were downloaded. The stromal and immune score were calculated using ESTIMATE. The differentially expressed genes (DEGs) with a high vs. low stromal score and a high vs. low immune score were screened and then functionally enriched. The tumor-infiltrating immune cells were investigated using the Cibersort algorithm, and the CD4+ and CD8+ T cell-related genes were identified using a Spearman correlation test of infiltrating abundance with the DEGs. Moreover, the miRNA-mRNA pairs and lncRNA-miRNA pairs were predicted to construct the competing endogenous RNAs (ceRNA) network. Kaplan-Meier (K-M) survival curves were also plotted.

RESULTS

In total, 478 DEGs with a high vs. low stromal score and 796 DEGs with a high vs. low immune score were identified. In addition, 39 CD4+ T cell-related genes and 78 CD8+ T cell-related genes were identified; of these, 14 genes were significantly associated with the prognosis of BRCA patients. Moreover, for CD4+ T cell-related genes, the chr22-38_28785274-29006793.1-miR-34a/c-5p-CAPN6 axis was identified from the ceRNA network, whereas the chr22-38_28785274-29006793.1-miR-494-3p-SLC9A7 axis was identified for CD8+ T cell-related genes.

CONCLUSIONS

The chr22-38_28785274-29006793.1-miR-34a/c-5p-CAPN6 axis and the chr22-38_28785274-29006793.1-miR-494-3p-SLC9A7 axis might regulate cellular activities associated with CD4+ and CD8+ T cell infiltration, respectively, in BRCA.

Tissue micro-RNAs associated with colorectal cancer prognosis: a systematic review

Colorectal cancer (CRC) is a multifactorial disease commonly diagnosed worldwide, with high mortality rates. Several studies demonstrate important associations between differential expression of micro-RNAs (miRs) and the prognosis of CRC. The present study aimed to identify differentially expressed tissue miRs associated with prognostic factors in CRC patients, through a systematic review of the Literature. Using the PubMed database, Cochrane Library and Web of Science, studies published in English evaluating miRs differentially expressed in tumor tissue and significantly associated with the prognostic aspects of CRC were selected. All the included studies used RT-PCR (Taqman or SYBR Green) for miR expression analysis and the period of publication was from 2009 to 2018. A total of 115 articles accomplished the inclusion criteria and were included in the review. The studies investigated the expression of 100 different miRs associated with prognostic aspects in colorectal cancer patients. The most frequent oncogenic miRs investigated were miR-21, miR-181a, miR-182, miR-183, miR-210 and miR-224 and the hyperexpression of these miRs was associated with distant metastasis, lymph node metastasis and worse survival in patients with CRC. The most frequent tumor suppressor miRs were miR-126, miR-199b and miR-22 and the hypoexpression of these miRs was associated with distant metastasis, worse prognosis and a higher risk of disease relapse (worse disease-free survival). Specific tissue miRs are shown to be promising prognostic biomarkers in patients with CRC, given their strong association with the prognostic aspects of these tumors, however, new studies are necessary to establish the sensibility and specificity of the individual miRs in order to use them in clinical practice.

Hsa-miR-494-3p attenuates gene HtrA3 transcription to increase inflammatory response in hypoxia/reoxygenation HK2 Cells

The occurrence of cardiac surgery-associated acute kidney injury (CSA-AKI) increases hospital stay and mortality. MicroRNAs has a crucial role in AKI. This objective of the current study is to explore the function of hsa-miR-494-3p in inflammatory response in human kidney tubular epithelial (HK2) cells with hypoxia/reoxygenation. According to KDIGO standard, patients after cardiac surgery with cardiopulmonary bypass were divided into two groups: AKI (n = 10) and non-AKI patients (n = 8). HK2 were raised in the normal and hypoxia/reoxygenation circumstances and mainly treated by overexpression ofmiR-494-3p and HtrA3. The relationship between miR-494-3p and HtrA3 was determined by dual-luciferase reporter assay. Our result showed that Hsa-miR-494-3p was elevated in the serum of patients with CSA-AKI, and also induced in hypoxic reoxygenated HK2 cells. Hsa-miR-494-3p also increased a hypoxia-reoxygenation induced inflammatory response in HK2 cells. Moreover, as a target gene of miR-494-3p, overexpression of HtrA3 downregulated the hypoxia-reoxygenation induced inflammatory response in HK2 cells. Overexpression of hsa-miR-494-3p-induced inflammatory response was inhibited by overexpression of HtrA3. Collectively, we identified that hsa-miR-494-3p, a miRNA induced in both circulation of AKI patients and hypoxia-reoxygenation-treated HK2 cells, enhanced renal inflammation by targeting HtrA3, which may suggest a possible role as a new therapeutic target for CSA-AKI.

Downregulation of MicroRNA-494 inhibits the TGF-β1/Smads signaling pathway and prevents the development of hypospadias through upregulating Nedd4L

BACKGROUND

Hypospadias, as a congenital disorder of the urethra, is the second most common birth abnormality of the male reproductive system. This study primarily investigates the effects of microRNA-494 (miR-494) on the transforming growth factor-β1 (TGF-β1)/Smads signaling pathway and on the development of hypospadias by binding to neural precursor cell expressed developmentally downregulated gene 4-like (Nedd4L).

METHODS

We induced a mouse model of hypospadias through di-(2-ethylhexyl) phthalate treatment. The underlying regulatory mechanisms of miR-494 in this model were analyzed upon treatment of miR-494 mimic, miR-494 inhibitor, or small interfering RNA against Nedd4L in urethral epithelial cells isolated from mice with hypospadias. We then verified the binding site between miR-494 and Nedd4L and applied a gain- and loss-of-function approach to determine the effects of miR-494 on cell proliferation, cycle distribution, and apoptosis.

RESULTS

Male mice with hypospadias exhibited significantly higher miR-494 expression and lower Nedd4L expression in urethral tissues than normal male mice. Nedd4L was verified as a target gene of miR-494. Treatment with miR-494 inhibitor suppressed the activation of the TGF-β1/Smads signaling pathway, whereas down-regulation of miR-494 exerted protective effects on urethral epithelial cells by impeding cell proliferation and inducing cell apoptosis.

CONCLUSIONS

The study indicates that downregulation of miR-494 inhibits the TGF-β1/Smads signaling pathway and prevents the development of hypospadias through upregulating Nedd4L.

FTY720 inhibits colon cancer cell survival and increases their sensitivity to gemcitabine through the miR-494/MST1 pathway

BACKGROUND

Colon cancer ranks 5th in both incidence and mortality among malignant tumors in China. Chemotherapy is the main treatment method. Studies have shown that immunosuppressive agent FTY720 has a certain inhibitory effect on cancer cell proliferation. Inhibitors combined with chemotherapy drugs can improve the therapeutic effect of cancer. In this study, immunosuppressive agent FTY720 and gemcitabine were used together to treat colon cancer cells, and the role of miR-494/mammalian Ste20-like kinase 1 (MST1) in the proliferation and apoptosis of colon cancer cells was explored, with an aim to provide a new treatment for colon cancer.

AIM

To investigate the effects of FTY720 and gemcitabine on the survival and apoptosis of colon cancer cells and the potential molecular mechanisms involved.

METHODS

Colon cancer SW1116 cells were treated with gemcitabine at concentrations of 0.0001 μg/mL, 0.001 μg/mL, 0.01 μg/mL, 0.1 μg/mL, and 1 μg/mL and FTY720 at concentrations of 2.5 μmol/L, 5 μmol/L, 7.5 μmol/L, 10 μmol/L, and 12.5 μmol/L. CCK8 assay and flow cytometry were applied to detect the survival rate and apoptosis rate of SW1116 cells. Quantitative real-time polymerase chain reaction was used to measure the levels of miR-494 and MST1 mRNA. Western blot was carried out to detect the expression levels of MST1, p21, and Caspase-3 proteins. Dual-luciferase reporter assay was performed to verify the relationship between miR-494 and MST1.

RESULTS

Gemcitabine and FTY720 reduced the survival rate of colon carcinoma SW1116 cells in a concentration dependent manner. According to the results, 0.1 μg/mL gemcitabine and 10 μmol/L FTY720 with an inhibition rate of about 50% were selected for subsequent experiments. Gemcitabine and FTY720 both inhibited cell survival and promoted cell apoptosis, and their combined use was better than the single use. Overexpression of miR-494 reversed the effects of FTY720 and gemcitabine on survival and apoptosis in SW1116 cells. MiR-494 targeted and regulated MST1. Inhibition of MST1 reversed the effects of FTY720 and gemcitabine on the survival and apoptosis in SW1116 cells.

CONCLUSION

FTY720 and gemcitabine inhibit SW1116 cell survival and promote apoptosis through the miR-494/MST1 pathway. The combination of FTY720 and gemcitabine has more significantly inhibitory effects on the survival and apoptosis of SW1116 cells.

FC-99 reduces macrophage tenascin-C expression by upregulating miRNA-494 in arthritis

The excessive production of inflammatory mediators by inflammatory cells contributes to the pathogenesis of rheumatoid arthritis. Tenascin-C (TN-C) is expressed in rheumatoid joint, and is associated with levels of inflammatory mediators. FC-99 (N1-[(4-methoxy)methyl]-4-methyl-1,2-Benzenediamine), a novel 1,2-benzenediamine derivative, was previously reported to block the prolonged expression of key rheumatoid arthritis inflammatory cytokines and relieve zymosan-induced joint inflammation. However, the specific mechanism is unknown. This study aimed to examine the effects of FC-99 on TN-C expression and inflammation and investigate its possible molecular mechanism. The results showed that FC-99 treatment reduced the high expression of TN-C in ankle joints of arthritis mice. Besides, FC-99 reduced the increased number of macrophages in arthritis mice, while did not change the number of synovioblasts. Concomitantly, expression of TN-C in synovial fibroblasts exhibited no difference between control and ZIA groups, and was not apparently altered following FC-99 treatment, while FC-99 decreased TN-C expression in macrophages both in vivo and in vitro. Meanwhile, TargetScan and luciferase assays indicated that TN-C was negatively regulated by miR-494. Transfection assay further demonstrated that FC-99 inhibited TN-C by targeting miR-494. Furthermore, the reduction of miR-494 mimic on expression of TN-C was associated with NF-κB pathway. Similarly, the down-regulation of FC-99 on TN-C was considerably decreased when NF-κB pathway was inhibited. These results indicated that FC-99 relieved macrophages inflammation via the miR-494/TN-C/NF-κB pathway, finally leading to the relief of inflammation in arthritis. The findings suggested that FC-99 might be a potential therapeutic candidate for the treatment of rheumatoid arthritis.

The potential role of regulatory microRNAs of RAS/MAPK signaling pathway in the pathogenesis of colorectal cancer

Colorectal cancer (CRC) is the leading cause of cancer death worldwide. Dysregulation of RAS/MAPK signaling axis is frequently found in CRC patients. The RAS/MAPK axis regulates cancer cell proliferation, apoptosis, inflammation, migration, and metastasis. Oncogenic or tumor-suppressor microRNAs (miRNAs) for RAS/MAPK signaling play a key role in the pathogenesis of CRC and are considered as novel potential biomarkers for diagnosis and prognosis of human malignancies. This review summarizes the current knowledge of mechanisms of action of RAS/MAPK miRNAs in the development and progression of CRC for a better understanding and hence a better management of this disease.

Role of Regulatory Oncogenic or Tumor Suppressor miRNAs of PI3K/AKT Signaling Axis in the Pathogenesis of Colorectal Cancer

Colorectal cancer (CRC) is the leading cause of cancer death worldwide and its incidence is increasing. In most patients with CRC, the PI3K/AKT signaling axis is over-activated. Regulatory oncogenic or tumor suppressor microRNAs (miRNAs) for PI3K/AKT signaling regulate cell proliferation, migration, invasion, angiogenesis, as well as resistance to chemo-/radio-therapy in colorectal cancer tumor tissues. Thus, regulatory miRNAs of PI3K/AKT/mTOR signaling represent novel biomarkers for new patient diagnosis and obtaining clinically invaluable information from post-treatment CRC patients for improving therapeutic strategies. This review summarizes the current knowledge of miRNAs' regulatory roles of PI3K/AKT signaling in CRC pathogenesis.

Insulin-like growth factor 2 mRNA-binding protein 1 promotes cell proliferation via activation of AKT and is directly targeted by microRNA-494 in pancreatic cancer

BACKGROUND

Studies have shown that insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) plays critical roles in the genesis and development of human cancers.

AIM

To investigate the clinical significance and role of IGF2BP1 in pancreatic cancer.

METHODS

Expression levels of IGF2BP1 and microRNA-494 (miR-494) were mined based on Gene Expression Omnibus datasets and validated in both clinical samples and cell lines by quantitative real-time polymerase chain reaction and Western blot. The relationship between IGF2BP1 expression and clinicopathological factors of pancreatic cancer patients was analyzed. The effect and mechanism of IGF2BP1 on pancreatic cancer cell proliferation were investigated in vitro and in vivo. Analyses were performed to explore underlying mechanisms of IGF2BP1 upregulation in pancreatic cancer and assays were carried out to verify the post-transcriptional regulation of IGF2BP1 by miR-494.

RESULTS

We found that IGF2BP1 was upregulated and associated with a poor prognosis in pancreatic cancer patients. We showed that downregulation of IGF2BP1 inhibited pancreatic cancer cell growth in vitro and in vivo via the AKT signaling pathway. Mechanistically, we showed that the frequent upregulation of IGF2BP1 was attributed to the downregulation of miR-494 expression in pancreatic cancer. Furthermore, we discovered that reexpression of miR-494 could partially abrogate the oncogenic role of IGF2BP1.

CONCLUSION

Our results revealed that upregulated IGF2BP1 promotes the proliferation of pancreatic cancer cells via the AKT signaling pathway and confirmed that the activation of IGF2BP1 is partly due to the silencing of miR-494.

miR-494 induces EndMT and promotes the development of HCC (Hepatocellular Carcinoma) by targeting SIRT3/TGF-β/SMAD signaling pathway

EndMT has an important effect on metastasis and progression of tumor. This work will elucidate the effect of miR-494 on EndMT and development of HCC. Therefore, the differential miRNA expression among non-tumorous, para-tumorous and tumorous tissues was analyzed. Moreover, luciferase activities of SIRT3 3′UTR treated with miR-494 were determined. Then human hepatoma cell lines were dealt with mimics or inhibitors of miR-494, migration and proliferation ability were assessed. The expression of SIRT3 and markers of mesenchymal cell were analyzed. The influences of miR-494 on development of HCC through inducing EndMT by targeting SIRT3 and TGF-β/SMAD signaling pathways in hepatoma cell lines were investigated. Xenograft mice were used to explore the potential roles of miR-494 on EndMT and development of HCC in vivo. Our results showed that, compared with non-tumorous tissues, 17 miRNAs were upregulated and 3 miRNAs were down-regulated in tumor tissues. In tumor tissues, the miR-494 expression level was much more than the expression of para-tumorous and non-tumorous tissues. MiR-494 suppressed SIRT3 expression, additionally enhanced expression of mesenchymal cell markers, while exerted effects on cell proliferation and migration of hepatoma cell lines. Moreover, the antagomir of miR-494 could protect against development process in xenogarft murine model. In conclusions, our work demonstrated that miR-494 targeted to SIRT3, and was a crucial mediator of EndMT and development of HCC through regulating SIRT3/TGF-β/SMAD signaling pathway. It suggested that aim at SIRT3/TGF-β/SMAD signaling pathway through suppressing the miR-494 expression level, was a feasible therapy strategy for HCC.

Diagnostic biomarker and therapeutic target applications of miR-326 in cancers: A systematic review

MicroRNAs (miRNAs) are endogenous mediators of RNA interference and have key roles in the modulation of gene expression under healthy, inflamed, stimulated, carcinogenic, or other cells, and tissues of a pathological state. Many studies have proved the association between miRNAs and cancer. The role of miR-326 as a tumor suppressor miRNA in much human cancer confirmed. We will explain the history and the role of miRNAs changes, especially miR-326 in cancers and other pathological conditions. Attuned with these facts, this review highlights recent preclinical and clinical research performed on miRNAs as novel promising diagnostic biomarkers of patients at early stages, prediction of prognosis, and monitoring of the patients in response to treatment. All related publications retrieved from the PubMed database, with keywords such as epigenetic, miRNA, microRNA, miR-326, cancer, diagnostic biomarker, and therapeutic target similar terms from 1899 to 2018 with limitations in the English language. Recently, researchers have focused on the impacts of miRNAs and their association in inflammatory, autoinflammatory, and cancerous conditions. Recent studies have suggested a major pathogenic role in cancers and autoinflammatory diseases. Investigations have explained the role of miRNAs in cancers, autoimmunity, and autoinflammatory diseases, and so on. The miRNA-326 expression has an important role in cancer conditions and other diseases.

Gonadotrophin-mediated miRNA expression in testis at onset of puberty in rhesus monkey: predictions on regulation of thyroid hormone activity and DLK1-DIO3 locus

Molecular mechanisms responsible for the initiation of primate spermatogenesis remain poorly characterized. Previously, 48 h stimulation of the testes of three juvenile rhesus monkeys with pulsatile LH and FSH resulted in down-regulation of a cohort of genes recognized to favor spermatogonia stem cell renewal. This change in genetic landscape occurred in concert with amplification of Sertoli cell proliferation and the commitment of undifferentiated spermatogonia to differentiate. In this report, the non-protein coding small RNA transcriptomes of the same testes were characterized using RNA sequencing: 537 mature micro-RNAs (miRNAs), 322 small nucleolar RNAs (snoRNAs) and 49 small nuclear RNAs (snRNAs) were identified. Pathway analysis of the 20 most highly expressed miRNAs suggested that these transcripts contribute to limiting the proliferation of the primate Sertoli cell during juvenile development. Gonadotrophin treatment resulted in differential expression of 35 miRNAs, 12 snoRNAs and four snRNA transcripts. Ten differentially expressed miRNAs were derived from the imprinted delta-like homolog 1-iodothyronine deiodinase 3 (DLK1-DIO3) locus that is linked to stem cell fate decisions. Four gonadotrophin-regulated expressed miRNAs were predicted to trigger a local increase in thyroid hormone activity within the juvenile testis. The latter finding leads us to predict that, in primates, a gonadotrophin-induced selective increase in testicular thyroid hormone activity, together with the established increase in androgen levels, at the onset of puberty is necessary for the normal timing of Sertoli cell maturation, and therefore initiation of spermatogenesis. Further examination of this hypothesis requires that peripubertal changes in thyroid hormone activity of the testis of a representative higher primate be determined empirically.

MiR-494 acts as a tumor promoter by targeting CASP2 in non-small cell lung cancer

MiR-494 plays an important role in several types of human cancers, including non-small cell lung cancer (NSCLC). Although the role of miR-494 has been investigated in several studies, the expression profile and underlying mechanism are still poorly understood. In this study, we found that overexpression of miR-494 promoted the proliferation and colony formation of NSCLC cells and reduced their sensitivity to cisplatin-induced apoptosis. By using microarray and Dual luciferase reporter assays, we further showed that caspase-2 (CASP2) is a functional target of miR-494, and the expression of CASP2 is inversely associated with miR-494 in vitro. In addition, miR-494 promoted the proliferation and colony formation of NSCLC cells and reduced their sensitivity to cisplatin-induced apoptosis by targeting CASP2. Therefore, our results suggest that miR-494 plays an oncomiR role in NSCLC cells and may be a candidate biomarker for malignant transformation and a therapeutic target of NSCLC.

Mechanisms of PTEN loss in cancer: It's all about diversity

PTEN is a phosphatase which metabolises PIP₃, the lipid product of PI 3-Kinase, directly opposing the activation of the oncogenic PI3K/AKT/mTOR signalling network. Accordingly, loss of function of the PTEN tumour suppressor is one of the most common events observed in many types of cancer. Although the mechanisms by which PTEN function is disrupted are diverse, the most frequently observed events are deletion of a single gene copy of PTEN and gene silencing, usually observed in tumours with little or no PTEN protein detectable by immunohistochemistry. Accordingly, with the exceptions of glioblastoma and endometrial cancer, mutations of the PTEN coding sequence are uncommon (<10%) in most types of cancer. Here we review the data relating to PTEN loss in seven common tumour types and discuss mechanisms of PTEN regulation, some of which appear to contribute to reduced PTEN protein levels in cancers.

Upregulation of serum miR-494 predicts poor prognosis in non-small cell lung cancer patients

OBJECTIVE

Emerging studies show that microRNAs (miRNAs) play a essential role in tumorigenesis. Deregulation of miR-494 is frequently observed in various human cancers including non-small cell lung cancer (NSCLC). However, little is known about the clinical significance of serum miR-494. The aim of this study was to investigate the diagnostic and prognostic value of serum miR-494 for NSCLC.

METHODS

We first compared miR-494 levels between NSCLC cell lines and lung bronchus epithelial cell line. A total of 90 NSCLC patients and 50 healthy controls were included in this study. MiR-494 levels were examined in serum samples by using real-time quantitative reverse transcription polymerase chain reactions. Association between serum miR-494 levels and the prognosis of NSCLC was further analyzed.

RESULTS

Our results showed that miR-494 was elevated in NSCLC cell lines. Serum miR-494 levels were significantly increased in patients with NSCLC compared to healthy controls. Area under receiver operating characteristic (ROC) curve was 85.4%. In addition, serum miR-494 levels decreased remarkably when patients received effective therapy. High serummiR-494 levels were significantly associated with higher incidence of lymph node metastasis, advanced clinical stage and higher histological grade. Moreover, survival analysis demonstrated that patients in the high serum miR-494 group had a poorer 5 year overall survival and disease free survival compared with the patients in the low serum miR-494 group. Multivariate analysis showed that serum miR-494 was an independent risk factor.

CONCLUSIONS

In conclusion, serum miR-494 was significantly elevated in NSCLC patients and closely correlated with poor clinical outcome, indicating that serum miR-494 might be a useful diagnostic and prognostic marker for NSCLC.

MicroRNA-493 inhibits the proliferation and invasion of osteosarcoma cells through directly targeting specificity protein 1

Osteosarcoma (OS) is the most common type of primary bone tumor and accounts for ~60% of all malignant bone tumors in children and adolescents. A large number of studies have proposed that the dysregulated and dysfunctional microRNAs may serve important roles in the occurrence, progression and metastasis of various types of human cancer, including OS. MicroRNA-493 (miR-493) has been identified to act as a tumor suppressor in several types of human cancer. However, little is known regarding the expression pattern and clinical significance of miR-493 in OS. In the present study, reverse transcription-quantitative polymerase chain reaction analysis revealed that miR-493 was markedly downregulated in OS tissues and cell lines and a low miR-493 level were associated with distant metastasis and clinical stage. Furthermore, functional experiments demonstrated that enforced expression of miR-493 led to a significant decrease in OS cell proliferation and invasion in vitro. Furthermore, through bioinformatics analysis, specificity protein 1 (SP1) was identified as a direct target gene of miR-493 in OS. Its expression was upregulated in OS tissues and was negatively associated with miR-493 expression levels. Inhibition of SP1 expression also suppressed the proliferation and invasion of OS, exerting a similar effect to that induced by miR-493 overexpression. These results suggested that miR-493 inhibited OS cell proliferation and invasion through negative regulation of SP1. Therefore, miR-493/SP1 may represent a potential therapeutic target for the treatment of OS.

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.

Deregulated expression of miR-29a-3p, miR-494-3p and miR-660-5p affects sensitivity to tyrosine kinase inhibitors in CML leukemic stem cells

The development of Imatinib mesylate (IM), which targets the oncogenic BCR-ABL fusion protein, has greatly improved the outcome of Chronic Myeloid Leukemia (CML) patients. However, BCR-ABL–positive progenitors can be detected in CML patients in complete cytogenetic response. Several evidence suggests that CML stem cells are intrinsically resistant to Tyrosine Kinase Inhibitors (TKI), and therefore they represent the most likely candidate responsible for disease relapse.

In this work, we investigated the microRNA (miRNA) expression profile of different subpopulations of CML Leukemic Stem Cells (LSCs): Lin-CD34+CD38- and Lin-CD34-CD38- cells. These cell fractions have been previously shown to be endowed with TKI intrinsic resistance. Our analysis identified 33 common deregulated miRNAs in CML LSCs. Among those, 8 miRNAs were deregulated in CML independently from BCR-ABL kinase activity and therefore are likely to be involved in the BCR-ABL-independent resistance to TKI that characterizes CML LSCs. In particular, the up-regulation of miR-29a-3p and miR-660-5p observed in CML LSCs, led to the down-regulation of their respective targets TET2 and EPAS1 and conferred TKI-resistance to CML LSCs in vitro. On the other hand, miR-494-3p down-regulation in CML LSCs, leading to c-MYC up-regulation, was able to decrease TKI-induced apoptosis. These results demonstrate that aberrant miRNA expression in CML LSCs could contribute to the intrinsic TKI-resistance observed in these cell populations, and support the development of novel therapies aimed at targeting aberrantly regulated miRNAs or their targets in order to effectively eradicate CML LSCs.

SRMDAP: SimRank and Density-Based Clustering Recommender Model for miRNA-Disease Association Prediction

Aberrant expression of microRNAs (miRNAs) can be applied for the diagnosis, prognosis, and treatment of human diseases. Identifying the relationship between miRNA and human disease is important to further investigate the pathogenesis of human diseases. However, experimental identification of the associations between diseases and miRNAs is time-consuming and expensive. Computational methods are efficient approaches to determine the potential associations between diseases and miRNAs. This paper presents a new computational method based on the SimRank and density-based clustering recommender model for miRNA-disease associations prediction (SRMDAP). The AUC of 0.8838 based on leave-one-out cross-validation and case studies suggested the excellent performance of the SRMDAP in predicting miRNA-disease associations. SRMDAP could also predict diseases without any related miRNAs and miRNAs without any related diseases.

miR-494 inhibits cervical cancer cell proliferation through upregulation of SOCS6 expression

It is unclear how microRNA (miR)-494 inhibits the proliferation of cervical cancer cells by altering the expression of SOCS6. Therefore, the present study aimed to investigate the molecular mechanism underlying miR-494 regulation of suppressor of cytokine signaling 6 (SOCS6) in human cervical cancer samples and the human cervical cancer HeLa cell line. The expression of miR-494 was determined using reverse transcription-quantitative polymerase chain reaction. In addition, TargetScan was used to predict miR-494 target genes and the luciferase reporter assay was used to determine whether SOCS6 was a direct target of miR-494. The results of the present study demonstrated that compared with the cervical intraepithelial neoplasia and normal cervical tissues, the miR-494 expression level in cervical cancer samples was significantly decreased (P<0.01). In addition, compared with normal cervical tissue, miR-494 expression level was significantly decreased in cervical intraepithelial lesions (P<0.05). Furthermore, the expression of miR-494 was associated with patients with or without lymph node metastasis, clinical stage and depth of stromal invasion (P<0.01); however, miR-494 expression was not identified to be associated with age, tumor size and menopausal status (P>0.05). Transfection of a miR-494 mimic significantly increased the expression level of miR-494 in HeLa cells (P<0.01), and anti-miR-494 transfection decreased the expression of miR-494 (P<0.01). An MTT proliferation assay and Boyden chamber invasion ability assay revealed that miR-494 mimic transfection significantly inhibited the proliferation, and invasion ability of HeLa cells (P<0.01), whereas anti-miR-494 transfection significantly increased the proliferation and invasion ability (P<0.05). SOCS6 was predicted, using bioinformatics, to be the target gene of miR-494 and this was validated using a luciferase reporter assay. Western blot analysis revealed that transfection of miR-494 significantly increased the expression of SOCS6 in HeLa cells, and transfection of anti-miR-494 significantly decreased the expression of SOCS6. Therefore, the results of the present study demonstrated that miR-494 expression in cervical cancer was significantly decreased. Exhibiting a decreased expression level of miR-494 may result in enhanced proliferative and invasive abilities of HeLa cell, thus contributing to the occurrence, and development of cervical cancer.

MiR-21 as prognostic biomarker in head and neck squamous cell carcinoma patients undergoing an organ preservation protocol

Despite progress in the treatment of head and neck squamous cell carcinoma (HNSCC) in recent decades, including new surgical techniques, radiotherapy advances and chemotherapy schedules, the prognosis for the affected patients has not improved at the same pace, and still, most HNSCC patients are diagnosed in advanced stages. To increase their survival, the development of better screening methods for early detection is required and appropriate tailored therapeutic interventions are desired. The aim of the present study was to evaluate miRNAs as prognostic biomarkers in patients undergoing organ preservation protocol for locally advanced HNSCC. For this purpose, we assessed the global miRNA expression profile of 15 HNSCC patients (‘screening set’) to identify miRNAs differentially expressed in responders and non-responders to therapy. Four miRNAs differentially expressed in HNSCC samples from the ‘screening set’ were validated in a different cohort of patients (47 samples - ‘validation set’). The results from the ‘validation set’ showed that the higher expression of one of these miRNAs, miR-21, was negatively associated with the treatment response to the organ preservation protocol (p=0.029). A multivariate analysis showed that, in a model adjusted for age, tumor site, p16 immunoexpression and tumor resectability, high expression of miR-21 remained an independent predictor of poor response to the organ preservation protocol (OR=5.69; 95%CI 1.27-25.58; p=0.023), together with clinical stage IV (OR=5.05; 95%CI 1.22-20.88; p=0.025). Furthermore, considering the entire cohort, patients with high expression of miR-21 had worse survival. A multivariate Cox regression analysis also showed miR-21 (HR=2.05; 95%CI 1.05-4.02; p=0.036) and clinical stage IV (HR=3.17; 95%CI 1.49-6.77; p=0.003) as independent prognostic factors (model adjusted for age, tumor site, tumor resectability, and sets ‘screening’ or ‘validation’).

In conclusion, the results of this study suggest that the evaluation of miR-21 expression could be an important tool for treatment planning and a prognosis predictior for HNSCC patients undergoing organ preservation protocols.

High Expression of TET1 Predicts Poor Survival in Cytogenetically Normal Acute Myeloid Leukemia From Two Cohorts

Ten-Eleven-Translocation 1 (TET1) plays a role in the DNA methylation process and gene activation. Recent reports suggest TET1 acts as an oncogene in leukemia development. However, the clinical relevance and biological insight of TET1 expression in cytogenetically normal acute myeloid leukemia (CN-AML) is unknown. In this study, quantification of TET1 transcript by real-time quantitative PCR in bone marrow blasts was performed in 360 CN-AML patients. As a result, high TET1 expression was more common in M0/M1 morphology and genes of NPM1 mutations, and underrepresented in CEBPA double allele mutations in our AML patients. In addition, we found overexpression of TET1 was associated with an inferior overall survival and event free survival in the two independent cohorts. Notably, mRNA and miRNA integrative analyses showed aberrant expression of several hub oncogenes appear to be regulated by some miRNAs like miR-127-5p, miR-494, miR-21 and miR-616 in high TET1 expressers. In conclusion, the TET1 gene expression might serve as a reliable predictor for patients survival in AML.

•

High TET1 mRNA expression is associated with poor survival in cytogenetically normal acute myeloid leukemia.

•

Several miRNAs and their targeting genes aberrantly expressed in high TET1 expressers.

•

These signatures can help us to decipher the poor clinical outcome of AML patients with high TET1 expression.

Patients with acute myeloid leukemia had a poor survival. In this study, we found the TET1 expression can be served as a survival predictor. High expression of TET1 was associated with short survival time. A group of microRNAs and their targeting genes coexpressed in high TET1 expressers. These aberrant expressed signatures can help us to explain the poor survival of patients with high TET1 expression, and be used as the potential drug target in the future.

Proliferation-associated miRNAs-494, -205, -21 and -126 detected by in situ hybridization: expression and prognostic potential in breast carcinoma patients

PURPOSE

To visualize by in situ hybridization (ISH) the levels of a set of proliferation-associated miRNAs and to evaluate their impact and clinical applicability in prognostication of invasive breast carcinoma.

METHODS

Tissue specimen from breast carcinoma patients were investigated for miRNAs-494, -205, -21 and -126. Prognostic associations for levels of miRNAs were analyzed based on complete clinical data and up to 22.5-year follow-up of the patient material (n = 285). For detection of the miRNAs, an automated sensitive protocol applying in situ hybridization was developed.

RESULTS

MiRNA-494 indicated prognostic value for patients with invasive breast carcinoma. Among node-negative disease reduced level of miRNA-494 predicted 8.5-fold risk of breast cancer death (p = 0.04). Altered levels and expression patterns of the studied miRNAs were observed in breast carcinomas as compared to benign breast tissue.

CONCLUSIONS

The present paper reports for the first time on the prognostic value of miRNA-494 in invasive breast cancer. Particularly, detection of miRNA-494 could benefit patients with node-negative breast cancer in identifying subgroups with aggressive disease. Based on our experience, the developed automatic ISH method to visualize altered levels of miRNAs-494, -205, -21 and -126 could be applied to routine pathology diagnostics providing that conditions of tissue treatment, especially fixation delays, are managed.

The epigenetically regulated miR-494 associates with stem-cell phenotype and induces sorafenib resistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the second cause of cancer-related mortality worldwide and is associated with poor prognosis, especially in patients not amenable for curative treatments. The multi-kinase inhibitor sorafenib represents the first-line treatment option for advanced HCC; nevertheless, its effectiveness is limited due to tumor heterogeneity as well as innate or acquired drug resistance, raising the need for new therapeutic strategies. MicroRNAs (miRNAs) involvement in treatment response as well as their safety and efficacy in preclinical models and clinical trials have been widely documented in the oncologic field, including HCC. Here, we identified miR-494 upregulation in a subgroup of human and rat HCCs with stem cell-like characteristics, as well as multiple epigenetic mechanisms involved in its aberrant expression in HCC cell lines and patients. Moreover, we identified p27, puma and pten among miR-494 targets, contributing to speed up cell cycle progression, enhance survival potential in stressful conditions and increase invasive and clonogenic capabilities. MiR-494 overexpression increased sorafenib resistance via mTOR pathway activation in HCC cell lines and, in line, high miR-494 levels associated with decreased sorafenib response in two HCC animal models. A sorafenib-combined anti-miR-494-based strategy revealed an enhanced anti-tumor potential with respect to sorafenib-only treatment in our HCC rat model. In conclusion, our findings suggested miR-494 as a possible therapeutic target as well as a candidate biomarker for patient stratification in advanced HCC.

MicroRNA-494 promotes cancer progression and targets adenomatous polyposis coli in colorectal cancer

Background

Aberrant activation of the Wnt/β-catenin signaling pathway is frequently observed in colorectal cancer (CRC). β-catenin is the major Wnt signaling pathway effector and inactivation of adenomatous polyposis coli (APC) results in nuclear accumulation of β-catenin. It has been suggested that inactivation of APC plays an important role in activation of the Wnt/β-catenin pathway and in the progression of colorectal tumorigenesis. However, the mechanism through which APC mediates colorectal tumorigenesis is not understood. Increasing evidence suggests that the dysregulation of microRNAs (miRNAs) is involved in colorectal tumorigenesis. Although miR-494 has been reported as being an upregulated miRNA, the interplay between miR-494 and APC-mediated colorectal tumorigenesis progression remains unclear.

Methods

The expression of miR-494 in tissues from patients diagnosed with CRC was analyzed using a microarray and real-time PCR. The effects of miR-494 on cell proliferation and tumorigenesis in CRC cells were analyzed by flow cytometry, colony formation assays, BrdU incorporation assays, and CCK8 assays. The correlation between miR-494 expression and APC expression, as well as the mechanisms by which miR-494 regulates APC in CRC were also addressed.

Results

miR-494 was significantly upregulated in CRC tissues, and this increase was negatively associated with APC expression. APC was confirmed to be a direct target of miR-494 in CRC. Furthermore, overexpression of miR-494 induced Wnt/β-catenin signaling by targeting APC, thus promoting CRC cell growth.

Conclusions

This study provides novel insights into the role of miR-494 in controlling CRC cell proliferation and tumorigenesis, and identifies miR-494 as a potential prognostic marker and therapeutic target.

miR-494 protects pancreatic β-cell function by targeting PTEN in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is one of the most common pregnancy complications characterized by insulin resistance and pancreatic β-cell dysfunction. Increasing evidence suggests that microRNAs (miRNAs) play key roles in the diverse types of diabetes, including GDM. However, the underlying mechanisms remain largely unknown. The purpose of this study is to investigate the role of microRNAs in GDM. The microarray data of dysregulated miRNAs in blood and placenta was retrieved in the GEO dataset under the accession number GSE19649. Quantitative reverse transcription PCR (qRT-PCR) was performed to analyze the expression levels of miR-494 in peripheral blood from twenty pairs of gestational diabetes (GDM) women and healthy women. Then, we investigated the effects of miR-494 on the insulin secretion of pancreatic β-cells. Moreover, the role of this miR-494 in regulating the proliferation and apoptosis of pancreatic β-cells were determined by MTT assay and flow cytometry, respectively in INS1 cells transfected with a miR-494 mimic or inhibitor. In addition, the direct target of miR-494 was confirmed using 3' untranslated region (UTR) luciferase reporter assay. Our data demonstrated that the miR-494 level was significantly decreased in the blood of GDM patients, and the low level was associated with a high concentration of blood glucose. Furthermore, overexpression of miR-494 improved pancreatic β-cell dysfunction by enhancing insulin secretion and total insulin content, inducing cell proliferation, and inhibiting cell apoptosis, whereas miR-494 knockdown exhibited decreased insulin secretion and proliferation, as well as stimulated apoptosis. In addition, phosphatase and tensin homolog (PTEN) which has been shown to play a pivotal role in apoptosis, was proved to be a direct target of miR-494 in pancreatic β-cells. More importantly, siRNA-induced downregulation of PTEN reversed the effects of miR-494 knockdown on insulin secretion, cell proliferation, and apoptosis of pancreatic β-cells.

Prognostic and clinicopathological significance of microRNA-494 overexpression in cancers: a meta-analysis

MicroRNA-494 was revealed as an attractive prognostic biomarker in recent studies. Nevertheless, the prognostic value of microRNA-494 in cancers remains controversial. Current meta-analysis aims to elucidate the precise predictive value of microRNA-494 in various cancers. Eligible studies were identified through multiple search strategies, the hazard ratios (HRs) and their confidence interval (CI) for patient prognostic outcomes were extracted and estimated. The pooled results of fifteen studies indicated that elevated expression of microRNA-494 implies a good overall survival of cancer patients (HR = 0.58, 95% CI: 0.36-0.91); While no significant association was found between the high expression of microRNA-494 and clinicopathological characteristic. Additionally, subgroup analysis revealed that overexpression of microRNA-494 predicted a worse overall survival in non-small cell lung cancer (HR = 2.35, 95% CI: 1.05-5.24) and colorectal cancer (HR = 2.59, 95% CI: 1.62-4.14). As per the subgroup analysis, the cancer type, the anatomy system classification and the ethnic background had influence on the overall survival result. Our findings indicate that elevated expression of microRNA-494 might predict a good overall survival in most cancers, while in non-small cell lung cancer and colorectal cancer, overexpression of microRNA-494 might predict a worse overall survival.

microRNA-494 is a potential prognostic marker and inhibits cellular proliferation, migration and invasion by targeting SIRT1 in epithelial ovarian cancer

Ovarian cancer is one of the most common types of gynecological malignancy worldwide, and is the fourth leading cause of cancer-associated mortality among women. Despite improvements in therapeutic treatments, the prognosis for epithelial ovarian cancer (EOC) remains poor, mainly due to the rapid growth and metastasis of ovarian cancer tumors. An increasing number of studies have indicated that microRNAs (miRNAs) are involved in the carcinogenesis and progression of human cancer, suggesting that miRNAs may be used in clinical prognosis and as a therapeutic target in EOC. The aim of the present study was to investigate the expression levels of miRNA-494 in EOC tissues and cell lines. The clinical significance of miRNA-494 in patients with EOC was also evaluated. The results demonstrated that miRNA-494 was significantly downregulated in EOC tissues and cell lines. Low expression levels of miRNA-494 were associated with poor prognostic features, including International Federation of Gynecology and Obstetrics stage, tumor size and lymph node metastasis. In vitro functional studies demonstrated that overexpression of miRNA-494 inhibited proliferation, migration and invasion in EOC cells. By contrast, knockdown of miRNA-494 enhanced cell growth, migration and invasion in EOC cells. Notably, sirtuin 1 (SIRT1) was identified as a direct target of miRNA-494 in EOC. Furthermore, MTT, cell migration and invasion assays verified that EOC cell proliferation, migration and invasion were completely restored with forced miRNA-494 expression and SIRT1 restoration. Together, these findings suggest that miRNA-494 is a potential prognostic marker, and may provide novel therapeutic regimens of targeted therapy for EOC.

MicroRNA-494 improves functional recovery and inhibits apoptosis by modulating PTEN/AKT/mTOR pathway in rats after spinal cord injury

Multiple cellular, molecular, and biochemical changes contribute to the etiology and treatment outcome of contusion spinal cord injury (SCI). MicroRNAs (miRNAs) aberrant expression have been found after SCI in recent studies. However, little is known about the functional significance of the unique role of miRNAs in SCI. Here, we established a rat SCI model and performed the miRNA microarray to analyze miRNAs expression at different times post-SCI. Microarray data revealed that 14 miRNAs were upregulated and 46 miRNAs were downregulated by 2 times compared with sham rat spinal cords, and miR-494 was one of the miRNAs being most significantly downregulated. Subsequently, we investigated miR-494 function and found that upregulation of miR-494 by agomir-494 improves functional recovery, reduces lesion size and inhibits apoptotic cell in rats following SCI. Moreover, our data showed that miR-494 suppresses phosphatase and tensin homolog (PTEN), a negative regulator of AKT/mTOR pathway, through directly targeting its 3'-UTR in BV-2 cells. Most importantly, we demonstrated that overexpression of miR-494 activates AKT/mTOR signaling pathway via inhibiting PTEN expression in rat SCI model. These findings suggested that miR-494 harbored the protective effect after SCI by modulating PTEN/AKT/mTOR pathway in rats and it is a potential candidate for SCI therapeutics.

Role of LOXL2 in the epithelial-mesenchymal transition and colorectal cancer metastasis

Colorectal cancer (CRC) is one of the most dangerous types of malignant tumors, and cancer metastasis is a major factor in the failure of CRC therapy. Recently, LOXL2 (lysyl oxidase-like 2) has been shown to represent a regulator of epithelial-mesenchymal transition (EMT) in different cancer types. However, LOXL2 has not been reported to be involved in CRC metastasis. In this study, we demonstrated that LOXL2 expression is strongly correlated with the rate of CRC metastasis, it participates in the regulation of EMT-related molecule expression in CRC cells in vitro, and it is involved in migratory potential alterations. Additionally, tissue microarray analysis of CRC patients showed an increase in the probability of developing CRC distant metastasis and a decrease in the survival rate of patients with high LOXL2 expression. The results obtained in this study indicate that LOXL2 is involved in the development and progression of CRC metastasis, and therefore, its expression levels may represent a useful prognostic marker.

Long Coding RNA XIST Contributes to Neuronal Apoptosis through the Downregulation of AKT Phosphorylation and Is Negatively Regulated by miR-494 in Rat Spinal Cord Injury

Recent evidence has suggested that long non-coding RNAs (lncRNAs) may play a significant role in the pathogenesis of several neurological diseases, including spinal cord injury (SCI). However, little is known about the role of lncRNAs in SCI. The aim of the present study was to evaluate the potential functions of lncRNAs in SCI and to identify the underlying mechanisms of action. We firstly analyzed Gene Expression Omnibus (GEO) datasets to investigate aberrantly-expressed lncRNAs which might be involved in the pathogenesis of SCI. The long non-coding RNA X-inactive specific transcript (XIST) was found to be one of the most significantly upregulated lncRNAs in the GEO dataset analysis, and is associated with apoptosis. We, therefore, selected this as a candidate lncRNA and investigated its function. We found that knockdown of lncRNA-XIST by Lv-shRNA had a prominent protective effect on SCI recovery by suppressing apoptosis through reactivation of the PI3K/AKT signaling pathway in rat spinal cord tissue. In particular, our results suggested that lncRNA-XIST may act as a competitive endogenous RNA, effectively becoming a sink for miR-494, leading to derepression of its target gene, phosphatase and tensin homolog deleted on chromosome ten (PTEN). In addition, an inverse relationship between lncRNA-XIST and miR-494 was observed in spinal cord tissues of SCI rats. Further study demonstrated that antagomiR-494 could reverse the protective effects of lncRNA-XIST knockdown on SCI rats through blocking the PTEN/PI3K/AKT signaling pathway. These results suggested that lncRNA-XIST knockdown may play an important role in limiting neuronal apoptosis in rats following SCI, and that the observed protective effects of lncRNA-XIST knockdown might have been mediated by its regulation on the phosphorylation of AKT by competitively binding miR-494. These findings have revealed, for the first time, the importance of the XIST/miR-494/PTEN/AKT signaling axis in the pathogenesis of SCI and suggest that lncRNA-XIST may be a promising molecular target for SCI therapy.

NR2F2 inhibits Smad7 expression and promotes TGF-β-dependent epithelial-mesenchymal transition of CRC via transactivation of miR-21

Metastasis is one of the most decisive factors influencing CRC patient prognosis and current studies suggest that a molecular mechanism known as EMT broadly regulates cancer metastasis. NR2F2 is a key molecule in the development of CRC, but the roles and underlying mechanisms of NR2F2 in TGF-β induced EMT in CRC remain largely unknown. In the current study, we were interested to examine the role of NR2F2 in the TGF-β-induced EMT in CRC. Here, we found NR2F2 was upregulated in CRC cells and promotes TGF-β-induced EMT in CRC. Using comparative miRNA profiling TGF-β pre-treated CRC cells in which NR2F2 had been knocked down with that of control cells, we identified miR-21 as a commonly downregulated miRNA in HT29 cells treated with TGF-β and NR2F2 siRNA, and its downregulation inhibiting migration and invasion of CRC cells. Moreover, we found NR2F2 could transcriptional activated miR-21 expression by binding to miR-21 promoter in HT29 by ChIP and luciferase assay. In the last, our data demonstrated that Smad7 was the direct target of miR-21 in CRC cells. Thus, NR2F2 could promote TGF-β-induced EMT and inhibit Smad7 expression via transactivation of miR-21, and NR2F2 may be a new common therapeutic target for CRC.

MicroRNA-141 inhibits tumor growth and minimizes therapy resistance in colorectal cancer

Colorectal cancer (CRC) is one of most common cancers and causes of cancer-associated mortality worldwide, due to its recurrence, metastasis and therapy resistance. Cancer stem cells (CSC) have been demonstrated to be vital for tumor initiation and recurrence. microRNAs may act as an oncogenes or tumor suppressors in numerous cancers. The present study demonstrated that microRNA-141 (miR‑141) was downregulated in CSC compared with differentiated cancer cells, and in tumor compared with healthy tissue. miR‑141 may inhibit CRC cell proliferation and the maintenance of CSC stemness, thereby enhancing drug susceptibility. In addition, the present study identified cyclin D2 as a novel target gene of miR‑141. In conclusion, the antitumor role of miR‑141 and its target cyclin D2 may suggest the development of miR‑141 as a potential therapeutic agent.

MicroRNA-494 inhibits breast cancer progression by directly targeting PAK1

MicroRNA (miRNA) is involved in the progression and metastasis of diverse human cancers, including breast cancer, as strong evidence has been found that miRNAs can act as oncogenes or tumor suppressor genes. Here, we show that miR-494 is decreased in human breast cancer specimens and breast cancer cell lines. Ectopic expression of miR-494 in basal-like breast cancer cell lines MDA-MB-231-LUC-D2H3LN and BT-549 inhibits clonogenic ability and metastasis-relevant traits in vitro. Moreover, ectopic expression of miR-494 suppresses neoplasm initiation as well as pulmonary metastasis in vivo. Further studies have identified PAK1, as a direct target gene of miR-494, contributes to the functions of miR-494. Remarkably, the expression of PAK1 is inversely correlated with the level of miR-494 in human breast cancer samples. Furthermore, re-expression of PAK1 partially reverses miR-494-mediated proliferative and clonogenic inhibition as well as migration and invasion suppression in breast cancer cells. Taken together, these findings highlight an important role for miR-494 in the regulation of progression and metastatic potential of breast cancer and suggest a potential application of miR-494 in breast cancer treatment.

Overexpression of Cdc20 in clinically localized prostate cancer: Relation to high Gleason score and biochemical recurrence after laparoscopic radical prostatectomy

OBJECTIVES

This study was aimed to explore Cdc20 expression and its correlation with clinicopathological characteristics and biochemical recurrence (BCR) after laparoscopic radical prostatectomy (LRP) in clinically localized prostate cancer (PCa).

METHODS

Cdc20 expression was examined by immunohistochemistry in 166 cases, including 60 cases of benign hyperplasia of prostate (BPH) patients treated by transurethral resection and 106 cases of consecutive PCa patients treated by LRP without neoadjuvant therapy in a single Chinese institution. The correlation with clinicopathological features and the predictive value for BCR were statistically analyzed.

RESULTS

Cdc20 expression was detected in 52 (86.7%) BPH and 97 (91.5%) PCa samples, which was statistically insignificant (P= 0.675). The rate of patients with high expression of Cdc20 was 21.7% in BPH and 37.7% in PCa (P= 0.033). A correlation was revealed between Cdc20 expression and postoperative Gleason scores (P= 0.046), positive surgical margin (P< 0.001). BCR-free survival was significantly lower in patients with high Cdc20 expression than those with low Cdc20 expression (P= 0.018). Univariate analysis indicated pTstage, post operative Gleason score, seminal vesicle invasion, lymph node invasion, surgical margin and Cdc20 expression significantly influenced BCR. Multivariate analysis revealed that postoperative Gleason score, seminal vesicle invasion, lymph node invasion, surgical margin and Cdc20 expression were independent predictors for BCR. After stratified by Gleason score and surgical margin status, Cdc20 expression and lymph node invasion remained significant in Cox regression analysis.

CONCLUSIONS

Overexpression of Cdc20 may serve as an independent predictor for BCR in patients of clinically localized PCa undergoing LRP without neoadjuvant therapy.

Activation of microRNA-494-targeting Bmi1 and ADAM10 by silibinin ablates cancer stemness and predicts favourable prognostic value in head and neck squamous cell carcinomas

Tumor initiating cells (TICs) possessing cancer stemness were shown to be enriched after therapy, resulting in the relapse and metastasis of head and neck squamous cell carcinomas (HNC). An effective therapeutic approach suppressing the HNC-TICs would be a potential method to improve the treatments for HNC. We observed that the treatment of silibinin (SB) dose dependently down-regulated the ALDH1 activity, CD133 positivity, stemness signatures expression, self-renewal property, and chemoresistance in ALDH1+CD44+ HNC-TICs. Using miRNA-microarray and mechanistic studies, SB increased the expression of microRNA-494 (miR-494) and both Bmi1 and ADAM10 were identified as the novel targets of miR-494. Moreover, overexpression of miR-494 results in a reduction in cancer stemness. However, knockdown of miR-494 in CD44⁻ALDH1⁻non-HNC-TICs enhanced cancer stemness and oncogenicity, while co-knockdown of Bmi1 and ADAM10 effectively reversed these phenomena. Mice model showed that SB treatment by oral gavage to xenograft tumors reduced tumor growth and prolonged the survival time of tumor-bearing mice by activation of miR-494-inhibiting Bmi1/ADAM10 expression. Survival analysis indicated that a miR494^highBmi1^lowADAM10^low phenotype predicted a favourable clinical outcome. We conclude that the inhibition of tumor aggressiveness in HNC-TICs by SB was mediated by up-regulation miR-494, suggesting that SB would be a valuable anti-cancer drug for treatment of HNC.

MicroRNA-494 inhibits cell proliferation and invasion of chondrosarcoma cells in vivo and in vitro by directly targeting SOX9

Accumulating evidence indicates that dysregulation of miRNAs could contribute to tumor growth and metastasis of chondrosarcoma by infuencing cell proliferation and invasion. In the current study, we are interested to examine the role of miRNAs in the carcinogenesis and progression of chondrosarcoma. Here, using comparative miRNA profiling of tissues and cells of chondrosarcoma and cartilage, we identified miR-494 as a commonly downregulated miRNA in the tissues of patients with chondrosarcoma and chondrosarcoma cancer cell line, and upregulation of miR-494 could inhibit proliferation and invasion of chondrosarcoma cancer cells in vivo and in vitro. Moreover, our data demonstrated that SOX9, the essential regulator of the process of cartilage differentiation, was the direct target and functional mediator of miR-494 in chondrosarcoma cells. And downregulation of SOX9 could also inhibit migration and invasion of chondrosarcoma cells. In the last, we identified low expression of miR-494 was significantly correlated with poor overall survival and prognosis of chondrosarcoma patients. Thus, miR-494 may be a new common therapeutic target and prognosis biomarker for chondrosarcoma.

3,39-Diindolylmethane Ameliorates Staphylococcal Enterotoxin B–Induced Acute Lung Injury through Alterations in the Expression of MicroRNA that Target Apoptosis and Cell-Cycle Arrest in Activated T Cells

3,39-Diindolylmethane (DIM), a natural indole found in cruciferous vegetables, has significant anti-cancer and anti-inflammatory properties. In this current study, we investigated the effects of DIM on acute lung injury (ALI) induced by exposure to staphylococcal enterotoxin B (SEB). We found that pretreatment of mice with DIM led to attenuation of SEB-induced inflammation in the lungs, vascular leak, and IFN-g secretion. Additionally, DIM could induce cell-cycle arrest and cell death in SEB-activated T cells in a concentration-dependent manner. Interestingly, microRNA (miRNA) microarray analysis uncovered an altered miRNA profile in lung-infiltrating mononuclear cells after DIM treatment of SEB-exposed mice. Moreover, computational analysis of miRNA gene targets and regulation networks indicated that DIM alters miRNA in the cell death and cell-cycle progression pathways. Specifically, DIM treatment significantly downregulated several miRNA and a correlative increase associated gene targets. Furthermore, overexpression and inhibition studies demonstrated that DIM-induced cell death, at least in part, used miR-222. Collectively, these studies demonstrate for the first time that DIM treatment attenuates SEB-induced ALI and may do so through the induction of microRNAs that promote apoptosis and cell-cycle arrest in SEB-activated T cells.

Nutrigenetics and Nutrimiromics of the Circadian System: The Time for Human Health

Even though the rhythmic oscillations of life have long been known, the precise molecular mechanisms of the biological clock are only recently being explored. Circadian rhythms are found in virtually all organisms and affect our lives. Thus, it is not surprising that the correct running of this clock is essential for cellular functions and health. The circadian system is composed of an intricate network of genes interwined in an intrincated transcriptional/translational feedback loop. The precise oscillation of this clock is controlled by the circadian genes that, in turn, regulate the circadian oscillations of many cellular pathways. Consequently, variations in these genes have been associated with human diseases and metabolic disorders. From a nutrigenetics point of view, some of these variations modify the individual response to the diet and interact with nutrients to modulate such response. This circadian feedback loop is also epigenetically modulated. Among the epigenetic mechanisms that control circadian rhythms, microRNAs are the least studied ones. In this paper, we review the variants of circadian-related genes associated to human disease and nutritional response and discuss the current knowledge about circadian microRNAs. Accumulated evidence on the genetics and epigenetics of the circadian system points to important implications of chronotherapy in the clinical practice, not only in terms of pharmacotherapy, but also for dietary interventions. However, interventional studies (especially nutritional trials) that include chronotherapy are scarce. Given the importance of chronobiology in human health such studies are warranted in the near future.