MiR-455-5p acts as a novel tumor suppressor in gastric cancer by down-regulating RAB18

IL-6 Accelerates the Proliferation and Metastasis of Pancreatic Cancer Cells via the miR-455-5p/IGF-1R Axis

Background: Pancreatic cancer (PaC) is a highly malignant gastrointestinal tumor with invasive and metastatic characteristics. Interleukin-6 (IL-6), a negative prognostic marker, contributes to PaC progression. However, the mechanism of IL-6 in PaC is not yet fully understood. Methods: miR-455-5p levels were first tested by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in PaC tissues or cells. Subsequently, PaC cell-related functions were identified through CCK-8, Transwell, and Western blotting. Changes in miR-455-5p and IGF-1R expression were confirmed using RT-qPCR and Western blotting. miR-455-5p methylation was assessed by bisulfite sequencing PCR. Results: The authors discovered that miR-455-5p was expressed at low levels in PaC tissues and cells, and miR-455-5p expression was observably reduced by IL-6 in PaC cells. In addition, IL-6 dramatically induces miR-455-5p methylation in PaC cells. Functionally, the data revealed that IL-6 could facilitate the malignant properties of PaC cells, including proliferation, epithelial-mesenchymal transition, and metastasis. The authors found that miR-455-5p could suppress the progression of PaC cells by downregulating IGF-1R in PaC cells. Mechanistically, IL-6 downregulated miR-455-5p and upregulated IGF-1R, and miR-455-5p reduced IGF-1R expression through targeted binding. Conclusions: The authors demonstrated that the miR-455-5p/IGF-1R axis is necessary for the induction of IL-6 in PaC progression. The results here may provide a theoretical basis for the application of the IL-6/miR-455-5p/IGF-1R axis in the clinical therapy of PaC.

miR-328-5p Induces Human Intervertebral Disc Degeneration by Targeting WWP2

Intervertebral disc degeneration (IDD) development is regulated by miRNA, including inflammatory reactions, cell apoptosis, and degradation of extracellular matrix. Nucleus pulposus cells apoptosis has a absolute influence in the development of IDD. This experiment explores the mechanism of miR-328-5p regulating IDD. Through the analysis of miRNA and mRNA microarray database, we screened the target genes miR-328-5p and WWP2. We verified the expression of miR-328-5p, WWP2, and related apoptotic genes in normal and degenerative nucleus pulposus tissues by qRT-PCR. The expressions of WWP2, Bcl-2, and Bax were detected by qRT-PCR and western blot after transfection to nucleus pulposus cell. The nucleus pulposus cell proliferation and apoptosis after transfection were confirmed by CCK8 and flow cytometry. Luciferase reporter assay and bioinformatics analyzed the targeting relationship between miR-328-5p and WWP2. Firstly, the qRT-PCR experiments confirmed the significant increase of miR-328-5p expression, while significant reduction of WWP2 in a degenerative tissues compared to the normal tissues. Surprisingly, miR-328-5p expression was positively, while that of WWP2 negatively correlated with the degeneration grade of IDD. And we also identified the high expression of Bax and Caspase3, while low expression of Bcl-2 in a degenerative tissues. After miR-328-5p mimic transfected into nucleus pulposus cell, qRT-PCR and western blot confirmed that WWP2 and Bcl-2 expressions were downregulated, while Bax and Caspase3 expressions were upregulated, and the same results were obtained by knocking down WWP2. CCK8 and flow cytometry confirmed that miR-328-5p inhibited the proliferation and induced apoptosis of nucleus pulposus cells. WWP2 is a target gene of miR-328-5p by bioinformatics and luciferase reporter assay. In summary, miR-328-5p targets WWP2 to regulate nucleus pulposus cells apoptosis and then participates in the development of IDD. Furthermore, this study may provide new references and ideas for IDD treatment.

Analysis of miRNA Expression Profiling of RIP2 Knockdown in Chicken HD11 Cells When Infected with Avian Pathogenic E. coli (APEC)

Colibacillosis is an acute and chronic avian disease caused by avian pathogenic E. coli (APEC). Previous studies have demonstrated that RIP2 plays a significant role in APEC infection. Moreover, increasing evidence indicates that microRNAs (miRNAs) are involved in host–pathogen interactions and the immune response. However, the role of miRNAs in the host against APEC infection remains unclear. Herein, we attempted to reveal new miRNAs potentially involved in the regulation of the immune and inflammatory response against APEC infection, with a particular focus on those possibly correlated with RIP2 expression, via miRNA-seq, RT-qPCR, Western blotting, dual-luciferase reporter assay, and CCK-8. The results showed that a total of 93 and 148 differentially expressed (DE) miRNAs were identified in the knockdown of RIP2 cells following APEC infection (shRIP2+APEC) vs. knockdown of RIP2 cells (shRIP2) and shRIP2 vs. wild-type cells (WT), respectively. Among those identified DE miRNAs, the biological function of gga-miR-455-5p was investigated. It was found that gga-miR-455-5p regulated by RIP2 was involved in the immune and inflammatory response against APEC infection via targeting of IRF2 to modulate the expression of type I interferons. Additionally, RIP2 could directly regulate the production of the type I interferons. Altogether, these findings highlighted the crucial role of miRNAs, especially gga-miR-455-5p, in host defense against APEC infection.

Multiomic analysis of microRNA-mediated regulation reveals a proliferative axis involving miR-10b in fibrolamellar carcinoma

Fibrolamellar carcinoma (FLC) is an aggressive liver cancer primarily afflicting adolescents and young adults. Most patients with FLC harbor a heterozygous deletion on chromosome 19 that leads to the oncogenic gene fusion, DNAJB1-PRKACA. There are currently no effective therapeutics for FLC. To address that, it is critical to gain deeper mechanistic insight into FLC pathogenesis. We assembled a large sample set of FLC and nonmalignant liver tissue (n = 52) and performed integrative multiomic analysis. Specifically, we carried out small RNA sequencing to define altered microRNA expression patterns in tumor samples and then coupled this analysis with RNA sequencing and chromatin run-on sequencing data to identify candidate master microRNA regulators of gene expression in FLC. We also evaluated the relationship between DNAJB1-PRKACA and microRNAs of interest in several human and mouse cell models. Finally, we performed loss-of-function experiments for a specific microRNA in cells established from a patient-derived xenograft (PDX) model. We identified miR-10b-5p as the top candidate pro-proliferative microRNA in FLC. In multiple human cell models, overexpression of DNAJB1-PRKACA led to significant upregulation of miR-10b-5p. Inhibition of miR-10b in PDX-derived cells increased the expression of several potentially novel target genes, concomitant with a significant reduction in metabolic activity, proliferation, and anchorage-independent growth. This study highlights a potentially novel proliferative axis in FLC and provides a rich resource for further investigation of FLC etiology.

miR-455-5p enhances 5-fluorouracil sensitivity in colorectal cancer cells by targeting PIK3R1 and DEPDC1

Our previous study has demonstrated that miR-455-5p was a tumor suppressor in colorectal cancer (CRC). This study aimed to investigate the role of miR-455-5p in 5-fluorouracil (5-Fu) in CRC. The expression of miR-455-5p, PIK3R1, and DEPDC1 was analyzed in HT-29 cells after treatment with different concentrations (0, 0.5, 2.5, and 12.5 μM) of 5-Fu. The effects of miR-455-5p on cell proliferation and apoptosis were analyzed by CCK-8 and flow cytometry. PIK3R1 and DEPDC1 were overexpressed to measure the mechanism of miR-455-5p on 5-Fu sensitivity. And the direct binding between miR-455-5p and DEPDC1 was detected by a dual-luciferase reporter assay. We found that miR-455-5p decreased, while PIK3R1 and DEPDC1 increased after 5-Fu treatment. miR-455-5p mimic significantly suppressed cell viability and elevated cell apoptosis in 5-Fu-treated HT-29 cells, whereas miR-455-5p inhibitor showed the opposite effects. Overexpression of PIK3R1 and DEPDC1 could attenuate the effects of miR-455-5p mimic on the viability and apoptosis of 5-Fu-treated cells. miR-455-5p could directly bind to DEPDC1 in HT-29 cells. In conclusion, miR-455-5p enhanced 5-Fu sensitivity by targeting PIK3R1 and DEPDC1 in CRC. This study provides a novel role of miR-455-5p in CRC and restoring miR-455-5p might be a therapeutic strategy to enhance chemosensitivity to 5-Fu.

microRNA-455-5p alleviates neuroinflammation in cerebral ischemia/reperfusion injury

Neuroinflammation is a major pathophysiological factor that results in the development of brain injury after cerebral ischemia/reperfusion. Downregulation of microRNA (miR)-455-5p after ischemic stroke has been considered a potential biomarker and therapeutic target for neuronal injury after ischemia. However, the role of miR-455-5p in the post-ischemia/reperfusion inflammatory response and the underlying mechanism have not been evaluated. In this study, mouse models of cerebral ischemia/reperfusion injury were established by transient occlusion of the middle cerebral artery for 1 hour followed by reperfusion. Agomir-455-5p, antagomir-455-5p, and their negative controls were injected intracerebroventricularly 2 hours before or 0 and 1 hour after middle cerebral artery occlusion (MCAO). The results showed that cerebral ischemia/reperfusion decreased miR-455-5p expression in the brain tissue and the peripheral blood. Agomir-455-5p pretreatment increased miR-455-5p expression in the brain tissue, reduced the cerebral infarct volume, and improved neurological function. Furthermore, primary cultured microglia were exposed to oxygen-glucose deprivation for 3 hours followed by 21 hours of reoxygenation to mimic cerebral ischemia/reperfusion. miR-455-5p reduced C-C chemokine receptor type 5 mRNA and protein levels, inhibited microglia activation, and reduced the production of the inflammatory factors tumor necrosis factor-α and interleukin-1β. These results suggest that miR-455-5p is a potential biomarker and therapeutic target for the treatment of cerebral ischemia/reperfusion injury and that it alleviates cerebral ischemia/reperfusion injury by inhibiting C-C chemokine receptor type 5 expression and reducing the neuroinflammatory response.

Expression, Interaction, and Role of Pseudogene Adh6-ps1 in Cancer Phenotypes

Pseudogenes have been classified as functionless and their annotation is an ongoing problem. The Adh6-ps1-a mouse pseudogene belonging to the alcohol dehydrogenase gene complex (Adh) was analyzed to review the conservation, homology, expression, and interactions and identify any role it plays in disease phenotypes using bioinformatics databases. Results showed that Adh6-ps1 have 2 transcripts (processed and unprocessed) which may have emerged from a transposition and duplication event, respectively, and that induced inversions (Uox gene, In(3)11Rk) involving gene complexes associated with Adh6-ps1 have been implicated in a diverse range of diseases. Adh6-ps1 is highly conserved in vertebrates particularly rodents and expressed in the liver. The top 5 MirRNA targets were Mir455, Mir511, Mir1903, Mir361, and Mir669o markers. While much is unknown about Mir1903 and Mir669o, the silencing of Mir455 and Mir511 is linked with hepatocellular carcinoma (HCC), and Mir361 is implicated in endometrial cancers. Given the identified MirRNA interactions with Adh6-ps1 and its expression in HCC and reproductive systems, it may well have a role in tumorigenesis and disease phenotypes. Nonetheless, further studies are required to establish these facts to add to the growing efforts to understand pseudogenes and their potential involvement in disease conditions.

Clinical significance of the serum miR-455-5p expression in patients with neonatal sepsis

Sepsis is a systemic inflammatory response caused by infection and is a major cause of neonatal death. This study explored the miR-455-5p in neonatal sepsis, and further investigated the diagnostic and prognostic value of miR-455-5p in neonatal sepsis (NS). The levels of serum miR-455-5p in 88 healthy controls and 90 NS patients were examined by quantitative real-time polymerase chain reaction (qRT-PCR). Pearson correlation coefficient was used to evaluate the correlation between miR-455-5p and clinical features. Receiver operating characteristic (ROC) curve analysis was performed for the diagnostic evaluation on miR-455-5p. The prognostic value of miR-455-5p in NS was analyzed by Kaplan-Meier survival curve and multivariate Cox regression. The expression of serum miR-455-5p in NS patients was highly expressed in comparison to healthy controls (P < 0.001), and the level of miR-455-5p was positively correlated with white blood cell count (WBC) and other clinical characteristics (P < 0.01). The AUC value of ROC curve was 0.895, suggesting that miR-455-5p had diagnostic value for NS. Survival analysis illustrated that patient with high miR-455-5p expression had poor prognosis (log rank P = 0.015), and miR-455-5p may be a potential prognostic marker for NS (HR = 3.454, 95% CI = 1.165-10.234, P = 0.025). The expression of miR-455-5p had the ability to distinguish NS from healthy people, and highly expressed miR-455-5p was associated with poor prognosis in NS patients.

MicroRNA-455-5p Contributes to Cholangiocarcinoma Growth and Mediates Galangin's Anti-Tumor Effects

Fully understanding the mechanism of how Cholangiocarcinoma (CCA) development and discovering promising therapeutic drugs are important to improve patients' survival time. This study identifies that microRNA-455-5p (miR-455-5p) targets protein phosphatase 1 regulatory subunit 12A (PPP1R12A), an effect that represses mitogen-activated protein kinase (MAPK) and PI3K/AKT pathway activation, thereby controlling CCA cells survival and metastasis. Moreover, miR-455-5p expression is reduced in CCA tissues and negative correlation with PPP1R12A and PPP1R12A knockdown phenotypic mimics miR-455-5p' effects on CCA cells. Furthermore, we demonstrate that galangin inhibits CCA growth both in vitro and in vivo, which is associated with increased miR-455-5p and repressed PPP1R12A expression. In support, overexpression of miR-455-5p abrogates those galangin-mediated anti-CCA effects. These findings establish an essential role of miR-455-5p in CCA development and galangin may provide a potential therapeutic adjuvant agent for anti-CCA treatment.

MicroRNA characteristics in epithelial ovarian cancer

The purpose of the current study was to clarify differences in microRNA expression according to clinicopathological characteristics, and to investigate if miRNA profiles could predict cytoreductive outcome in patients with FIGO stage IIIC and IV ovarian cancer. Patients enrolled in the Pelvic Mass study between 2004 and 2010, diagnosed and surgically treated for epithelial ovarian cancer, were used for investigation. MicroRNA was profiled from tumour tissue with global microRNA microarray analysis. Differences in miRNA expression profiles were analysed according to histologic subtype, FIGO stage, tumour grade, type I or II tumours and result of primary cytoreductive surgery. One microRNA, miR-130a, which was found to be associated with serous histology and advanced FIGO stage, was also validated using data from external cohorts. Another seven microRNAs (miR-34a, miR-455-3p, miR-595, miR-1301, miR-146-5p, 193a-5p, miR-939) were found to be significantly associated with the clinicopathological characteristics (p ≤ 0.001), in our data, but mere not similarly significant when tested against external cohorts. Further validation in comparable cohorts, with microRNA profiled using newest and similar methods are warranted.

miR-455 Inhibits the Viability and Invasion by Targeting RAB18 in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) has been regarded as the fifth most common cancer worldwide with a low prognosis. miR-455 usually played the role of a tumor suppressor in multiple cancers. The aim of this study was to investigate the roles of miR-455 in HCC.

Materials and Methods

Cell viability and invasion were measured by CCK8 and Transwell assays. Luciferase reporter assay was performed to verify that miR-455 directly binds to the 3′-noncoding region (UTR) of RAB18 mRNA in Huh7 cells.

Results

The expression of miR-455 was lower in HCC tissues and cell lines than in nontumor tissues and normal cell line, and downregulation of miR-455 was connected with worse outcome of HCC patients. miR-455 suppressed cell proliferation in vitro and in vivo, and it inhibited the abilities of cell invasion and EMT in HCC. RAB18 was upregulated in HCC tissues and cell lines, and the expression of RAB18 was regulated by miR-455. RAB18 reversed partial roles of miR-455 on cell viability and invasion in HCC.

Conclusion

miR-455 inhibited cell viability and invasion by directly targeting the 3′-UTR of RAB18 mRNA of hepatocellular carcinoma.

Screening of miRNAs associated with lymph node metastasis in Her-2-positive breast cancer and their relationship with prognosis

The aim of this study was to identify some biomarkers for predicting lymph node metastasis and prognosis of human epidermal growth factor receptor 2 (Her-2)-positive breast cancer (BC). We analyzed correlations between microRNAs (miRNAs) and the prognosis of patients with BC based on data collected from The Cancer Genome Atlas (TCGA) database. The expression levels of miR-455, miR-143, and miR-99a were measured in clinical samples of Her-2-positive BC patients with different degrees of lymph node metastasis. We investigated the impacts of overexpressed miR-455 on the proliferation and invasiveness of MDA-MB-453 cells and measured its effects on the expression of long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of miR-455 was significantly and positively correlated to the prognosis and overall survival (OS) of the BC (P=0.028), according to TCGA information. The expression level of miR-455 was positively correlated with OS and relapse-free survival (RFS) of patients with Her-2-positive BC, and was negatively correlated with the number of metastatic lymph nodes (P<0.05). Transwell assay suggested that MDA-MB-453 cells became much less invasive (P<0.01) after being transfected with miR-455 mimics. During the qRT-PCR, the expression level of MALAT1 declined significantly after transfection (P<0.01). Overexpressed miR-455 significantly inhibited the proliferation and migration of MDA-MB-453 cells and the expression of MALAT1. We conclude that miR-455 may be a useful potential biomarker for forecasting lymph node metastasis and the prognosis of Her-2-positive BC patients. miR-455 may play an important role in lymph node metastasis of BC by interacting with MALAT1.

Reduction of Bladder Cancer Chemosensitivity Induced by the Effect of HOXA-AS3 as a ceRNA for miR-455-5p That Upregulates Notch1

Chemoresistance is one of the main causes of recurrence in bladder cancer patients and leads to poor prognosis. Recently, long non-coding RNAs, like HOXA-AS3, have been reported to regulate chemoresistance in several types of cancer. In this study, we aimed to determine whether HOXA-AS3 can mediate cisplatin resistance in bladder cancer, and its potential mechanism of action. We determined the viability, proliferation, and apoptosis of bladder cancer cells using a CCK-8 assay, EdU staining, and flow cytometry, respectively. We used western blot analysis to assess the expression of markers of epithelial-mesenchymal transition (EMT) and Notch1. We then confirmed expression of these EMT-related markers by immunofluorescence analysis. We found that hypoxia promoted resistance to cisplatin and upregulated the level of HOXA-AS3 in BC cells. Inhibition of HOXA-AS3 enhanced hypoxia-induced cisplatin sensitivity by regulating EMT and Notch1 in BC cells. A dual-luciferase reporter assay confirmed that HOXA-AS3 directly targets miR-455-5p and that Notch1 was a potential target of miRNA-455-5p. We also found that the positive effect of HOXA-AS3 inhibition on cisplatin resistance and tumorigenesis was alleviated when BC cells were transfected with miR-455-5p. Finally, we showed combining HOXA-AS3 small interfering RNA (siRNA) with cisplatin treatment inhibited tumorigenesis in a BALB/c nu/nu mouse model. Our findings indicate that HOXA-AS3 may function as a competing endogenous RNA (ceRNA) of miR-455-5p to regulate Notch1 and play an important role in regulating chemotherapeutic drug sensitivity in BC cells. Therefore, HOXA-AS3 may be a novel therapeutic target for treating bladder cancer.

Three novel circRNAs upregulated in tissue and plasma from hepatocellular carcinoma patients and their regulatory network

Background

The regulatory roles of circular RNAs (circRNAs) in tumorigenesis have attracted increasing attention. However, novel circRNAs with the potential to be used as serum/plasma biomarkers and their regulatory mechanism in the pathogenesis of hepatocellular carcinoma (HCC) remain explored.

Methods

CircRNA expression profiles of tumor tissues and plasma samples from HCC patients were compiled and jointly analyzed. CircRNA–miRNA–mRNA interactions were predicted by bioinformatics tools. The expression of interacting miRNAs and mRNA was verified in independent datasets. Survival analysis and pathway enrichment analysis were conducted on hub genes.

Results

We identified three significantly up-regulated circRNAs (hsa_circ_0009910, hsa_circ_0049783, and hsa_circ_0089172) both in HCC tissues and plasma samples. Two of them were validated to be indeed circular and could be excreted from hepatoma cells. We further revealed four miRNAs (hsa-miR-455-5p, hsa-miR-615-3p, hsa-miR-18a-3p, hsa-miR-4524a-3p) that targeting circRNAs and expressed in human HCC samples, and 95 mRNAs targeted by miRNAs and significantly up-regulated in two HCC cohorts. A protein-protein interaction network revealed 19 hub genes, 12 of them (MCM6, CCNB1, CDC20, NDC80, ZWINT, ASPM, CENPU, MCM3, MCM5, ECT2, CDC7, and DLGAP5) were associated with reduced survival in two HCC cohorts. KEGG, Reactome, and Wikipathway enrichment analysis indicated that the hub genes mainly functioned in DNA replication and cell cycle.

Conclusions

Our study uncovers three novel deregulated circRNAs in tumor and plasma from HCC patients and provides an insight into the pathogenesis from the circRNA–miRNA–mRNA regulatory network.

LncRNA RNF144A-AS1 Promotes Bladder Cancer Progression via RNF144A-AS1/miR-455-5p/SOX11 Axis

Background

Bladder cancer (BC) is the most commonly occurring malignant tumor of the urinary system worldwide. Long non-coding RNAs (lncRNAs), including lncRNA RNF144A-AS1 (RNF144A-AS1), perform an oncogenic role in BC progression. However, how RNF144A-AS1 is regulated in BC has not been fully investigated, and its role in BC is mostly obscure. In this study, we explore its role in BC progression.

Materials and Methods

The expression level of RNF144A-AS1 in BC tissues was explored via bioinformatics analysis and quantitative real-time PCR (qRT-PCR). We used RNF144A-AS1 siRNA (si-RNF144A-AS1) to inhibit the RNF144A-AS1 level in BC cell lines (J82 and 5637 cells). A series of experimental studies in vitro (CCK-8 assay, colony formation assay and Transwell assay) was performed to explore the role of si-RNF144A-AS1 on the proliferation, migration and invasion of J82 and 5637 cells. A BC xenograft model was established, and the effect of si-RNF144A-AS1 on xenograft growth was explored in vivo. The interactions among RNF144A-AS1, miR-455-5p and SOX11 were predicted by bioinformatics miRanda and Targetscan database, and verified by the luciferase reporter assay and RNA pull-down assay. Finally, miR-455-5p inhibitor and si-RNF144A-AS1 were cotransfected into J82 and 5637 cells.

Results

RNF144A-AS1 is overexpressed in BC tumors and cells, and its overexpression is correlated with poor prognosis. Knockdown of RNF144A-AS1 markedly suppressed the proliferation, migration and invasion of J82 and 5637 cells and significantly inhibited xenograft growth in nude mice, compared to si-NC. We found that RNF144A-AS1 serves as a sponge for miR-455-5p. Furthermore, a binding site of miR-455-5p was found in 3ʹ UTR of SOX11 gene, and overexpression of miR-455-5p suppressed SOX11 levels. RNF144A-AS1 knockdown markedly decreased SOX11 expression levels, while miR-455-5p inhibitor restored this repressive effect. Restoration of SOX11 could reverse this repressive effect of RNF144A-AS1 on cell proliferation, migration and invasion abilities.

Conclusion

Overall, our findings underline the critical role of RNF144A-AS1 in BC development, and our study reveals for the first time that RNF144A-AS1 promotes BC progression via the RNF144A-AS1/miR-455-5p/SOX11 axis.

miRNAs expression signature potentially associated with lymphatic dissemination in locally advanced prostate cancer

Background

Prostate cancer is one of the most common and socially significant cancers among men. The aim of our study was to reveal changes in miRNA expression profiles associated with lymphatic dissemination in prostate cancer and to identify the most prominent miRNAs as potential prognostic markers for future studies.

Methods

High-throughput miRNA sequencing was performed for 44 prostate cancer specimens taken from Russian patients, with and without lymphatic dissemination (N1 – 20 samples; N0 – 24 samples).

Results

We found at least 18 microRNAs with differential expression between N0 and N1 sample groups: miR-182-5p, miR-183-5p, miR-96-5p, miR-25-3p, miR-93-5p, miR-7-5p, miR-615-3p, miR-10b, miR-1248 (N1-miRs; elevated expression in N1 cohort; p < 0.05); miR-1271-5p, miR-184, miR-222-3p, miR-221-5p, miR-221-3p, miR-455-3p, miR-143-5p, miR-181c-3p and miR-455-5p (N0-miRs; elevated expression in N0; p < 0.05). The expression levels of N1-miRs were highly correlated between each other (the same is applied for N0-miRs) and the expression levels of N0-miRs and N1-miRs were anti-correlated. The tumor samples can be divided into two groups depending on the expression ratio between N0-miRs and N1-miRs.

Conclusions

We found the miRNA expression signature associated with lymphatic dissemination, in particular on the Russian patient cohort. Many of these miRNAs are well-known players in either oncogenic transformation or tumor suppression. Further experimental studies with extended sampling are required to validate these results.

Rab18 regulates focal adhesion dynamics by interacting with kinectin-1 at the endoplasmic reticulum

The members of the Rab family of small GTPases are molecular switches that regulate distinct steps in different membrane traffic pathways. In addition to this canonical function, Rabs can play a role in other processes, such as cell adhesion and motility. Here, we reveal the role of the small GTPase Rab18 as a positive regulator of directional migration in chemotaxis, and the underlying mechanism. We show that knockdown of Rab18 reduces the size of focal adhesions (FAs) and influences their dynamics. Furthermore, we found that Rab18, by directly interacting with the endoplasmic reticulum (ER)-resident protein kinectin-1, controls the anterograde kinesin-1–dependent transport of the ER required for the maturation of nascent FAs and protrusion orientation toward a chemoattractant. Altogether, our data support a model in which Rab18 regulates kinectin-1 transport toward the cell surface to form ER–FA contacts, thus promoting FA growth and cell migration during chemotaxis.

MicroRNA-455-5p exerts inhibitory effect in cervical carcinoma through targeting S1PR1 and blocking mTOR pathway

BACKGROUND

MicroRNAs (miRNAs) have been increasingly exploited in human malignancies. The regulation of microRNA-455-5p (miR-455-5p) has been shown in several cancers, except for cervical carcinoma. Therefore, the role of miR-455-5p was exploited in cervical carcinoma.

METHODS

The qRT-PCR experiment was used to assess miR-455-5p and S1PR1 expression levels. We explored the function of miR-455-5p through MTT and Transwell assays. The mTOR pathway and cell apoptosis were detected by Western blot assays. The relationship between miR-455-5p and S1PR1 was testified by dual-luciferase reporter assay.

RESULTS

MiR-455-5p expression was decreased in cervical carcinoma, which was related to poor clinical outcome in cervical carcinoma patients. MiR-455-5p inhibited cell viability and metastasis in cervical carcinoma. Further, S1PR1 is a direct target of miR-455-5p. S1PR1 recovered the inhibition of cell viability and metastasis induced by miR-455-5p in cervical carcinoma. In addition, miR-455-5p induced cell apoptosis and inactivated the mTOR pathway in cervical carcinoma.

CONCLUSION

MiR-455-5p exerts inhibitory effect in cervical carcinoma through targeting S1PR1 and blocking the mTOR pathway.

CircPIP5K1A activates KRT80 and PI3K/AKT pathway to promote gastric cancer development through sponging miR-671-5p

BACKGROUND

Gastric cancer (GC) has been regarded as a kind of the most common cancers in gastrointestinal malignant tumors. Circular RNA (circRNA) is a newly discovered category of non-coding RNAs and plays a significant role in the initiation or development of human cancers. Nevertheless, the role of circPIP5K1A in GC remains unclear.

METHODS

The relative expression level and the circular structure of circPIP5K1A were confirmedby RT-qPCR. The biological function of circPIP5K1A in GC was evaluated by colony formation, transwell and western blot assays. The binding capacity between miR-671-5p and circPIP5K1A (or KRT80) was assessed by luciferase reporter and Ago2-RIP assays. Protein levels of PI3K/AKT pathway were measured by western blot assay.

RESULTS

CircPIP5K1A was up-regulated in GC tissues and cells with a circular structure. Functionally, circPIP5K1A silence limited cell proliferation, invasion, migration and EMT process. Mechanistically, circPIP5K1A directly interacted with miR-671-5p to modulate KRT80 expression. Either miR-671-5p inhibitor or KRT80 overexpression could offset the inhibitory effect of circPIP5K1A depletion on GC development. Besides, circPIP5K1A played its oncogenic role in GC through regulating PI3K/AKT pathway. At last, circPIP5K1A promoted GC tumor growth in vivo.

CONCLUSIONS

CircPIP5K1A/miR-671-5p/KRT80 axis contributes to GC progression through PI3K/AKT pathway, implying this axis may be a potential therapeutic target for the treatment of GC patients.

PVT1 Long Non-coding RNA in Gastrointestinal Cancer

Whole genome and transcriptome sequencing technologies have led to the identification of many long non-coding RNAs (lncRNAs) and stimulated the research of their role in health and disease. LncRNAs participate in the regulation of critical signaling pathways including cell growth, motility, apoptosis, and differentiation; and their expression has been found dysregulated in human tumors. Thus, lncRNAs have emerged as new players in the initiation, maintenance and progression of tumorigenesis. PVT1 (plasmacytoma variant translocation 1) lncRNA is located on chromosomal 8q24.21, a large locus frequently amplified in human cancers and predictive of increased cancer risk in genome-wide association studies (GWAS). Combined, colorectal and gastric adenocarcinomas are the most frequent tumor malignancies and also the leading cause of cancer-related deaths worldwide. PVT1 expression is elevated in gastrointestinal tumors and correlates with poor patient prognosis. In this review, we discuss the mechanisms of action underlying PVT1 oncogenic role in colorectal and gastric cancer such as MYC upregulation, miRNA production, competitive endogenous RNA (ceRNA) function, protein stabilization, and epigenetic regulation. We also illustrate the potential role of PVT1 as prognostic biomarker and its relationship with resistance to current chemotherapeutic treatments.

miR-145-5p Acts as a Novel Tumor Suppressor in Hepatocellular Carcinoma Through Targeting RAB18

Micro-RNAs play critical roles in initiation and progression of hepatocellular carcinoma. However, the biological role of microRNA-145-5p in hepatocellular carcinoma and how it works are still not clearly understood. Expression levels of microRNA-145-5p in hepatocellular carcinoma cell lines were examined by reverse transcription quantitative polymerase chain reaction. Cell counting kit-8, wound-healing assay, and flow cytometry assay were conducted to investigate the role of microRNA-145-5p von proliferation, migration, and apoptosis. Luciferase reporter assay and Western blot were performed to investigate the correlation between microRNA-145-5p and RAB18. We found microRNA-145-5p was downregulated in hepatocellular carcinoma cell lines compared to the normal cell line. Overexpression of microRNA-145-5p inhibited the proliferation and migration but promoted apoptosis of hepatocellular carcinoma cells in vitro. RAB18 was validated a target of microRNA-145-5p and ectopic expression of RAB18 can promote the proliferation and migration but inhibit apoptosis of hepatocellular carcinoma cells. These findings indicate that microRNA-145-5p functions as a novel tumor suppressor through targeting RAB18, suggesting that microRNA-145-5p might be a potential new therapeutic molecule for the treatment of hepatocellular carcinoma.

MicroRNA gga-miR-455-5p suppresses Newcastle disease virus replication via targeting cellular suppressors of cytokine signaling 3

Newcastle disease (ND) is an acute and contagious avian disease caused by Newcastle disease virus (NDV). MicroRNAs (miRNAs) play a significant role in host-pathogen interactions and the innate immune response. However, the role of miRNAs in the host response to NDV infection is not clearly understood. In this study, we showed that expression of the cellular miRNA gga-miR-455-5p was downregulated in vivo and in vitro in response to NDV infection. Next, we found that the transfection of chicken embryonic fibroblasts (CEFs) with gga-miR-455-5p suppressed NDV replication, while the blockade of endogenous gga-miR-455-5p expression with inhibitors enhanced NDV replication. In addition, gga-miR-455-5p enhanced the expression of type I interferon and the interferon-inducible genes (ISGs) OASL and Mx1 by targeting SOCS3, a negative regulator of type I IFN signaling. Altogether, these findings highlight the crucial role of gga-miR-455-5p in host defense against NDV by targeting the SOCS3 gene to inhibit NDV replication.

Identification of novel genes associated with a poor prognosis in pancreatic ductal adenocarcinoma via a bioinformatics analysis

Pancreatic ductal adenocarcinoma (PDAC) is a class of the commonest malignant carcinomas. The present study aimed to elucidate the potential biomarker and prognostic targets in PDAC. The array data of GSE41368, GSE43795, GSE55643, and GSE41369 were downloaded from Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) and differentially expressed microRNAs (DEmiRNAs) in PDAC were obtained by using GEO2R, and overlapped DEGs were acquired with Venn Diagrams. Functional enrichment analysis of overlapped DEGs and DEmiRNAs was conducted with Metascape and FunRich, respectively. The protein-protein interaction (PPI) network of overlapped DEGs was constructed by STRING and visualized with Cytoscape. Overall survival (OS) of DEmiRNAs and hub genes were investigated by Kaplan-Meier (KM) plotter (KM plotter). Transcriptional data and correlation analyses among hub genes were verified through GEPIA and Human Protein Atlas (HPA). Additionally, miRNA targets were searched using miRTarBase, then miRNA-DEG regulatory network was visualized with Cytoscape. A total of 32 DEmiRNAs and 150 overlapped DEGs were identified, and Metascape showed that DEGs were significantly enriched in cellular chemical homeostasis and pathways in cancer, while DEmiRNAs were mainly enriched in signal transduction and Glypican pathway. Moreover, seven hub genes with a high degree, namely, V-myc avian myelocytomatosis viral oncogene homolog (MYC), solute carrier family 2 member 1 (SLC2A1), PKM, plasminogen activator, urokinase (PLAU), peroxisome proliferator activated receptor γ (PPARG), MET proto-oncogene, receptor tyrosine kinase (MET), and integrin subunit α 3 (ITGA3), were identified and found to be up-regulated between PDAC and normal tissues. miR-135b, miR-221, miR-21, miR-27a, miR-199b-5p, miR-143, miR-196a, miR-655, miR-455-3p, miR-744 and hub genes predicted poor OS of PDAC. An integrative bioinformatics analysis identified several hub genes that may serve as potential biomarkers or targets for early diagnosis and precision target treatment of PDAC.

Microarray expression profiles analysis revealed lncRNA OXCT1-AS1 promoted bladder cancer cell aggressiveness via miR-455-5p/JAK1 signaling

Bladder cancer (BCa) is one of the most prevalent cancers of the urinary system worldwide. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) perform a vital function in the pathogenesis and progression of BCa. In the current study, we identified a novel lncRNA OXCT1-AS1 and investigated its role and potential mechanisms in BCa. The microarray results showed the expression of lncRNAs, microRNAs, and messenger RNAs between BCa primary tumor tissues and metastatic lymph nodes were significantly different. The quantitative polymerase chain reaction verification was performed to ensure the reliability of the screening results. The Cell Counting Kit 8 and transwell assay were used to assess the tumor cell proliferation and invasion abilities in vitro, respectively. The dual-luciferase activity assay was performed to investigate the potential mechanism of competing endogenous RNA network. lncRNA OXCT1-AS1, which elevated in metastasis lymph node, was significantly upregulated in BCa cell lines compared with SVHUC-1. We demonstrated OXCT1-AS1 inhibited miR-455-5p to decrease its binding to the JAK1 3'-untranslated region, which could upregulate the expression of JAK1 at the protein level, thus promoting BCa proliferation and invasion. Therefore, lncRNA OXCT1-AS1 could act as a potential biomarker and therapeutic target for patients with BCa.

Clinicopathological implications of TIM3+ tumor-infiltrating lymphocytes and the miR-455-5p/Galectin-9 axis in skull base chordoma patients

Chordoma is difficult to eradicate due to high local recurrence rates. The immune microenvironment is closely associated with tumor prognosis; however, its role in skull base chordoma is unknown. The expression of Galectin-9 (Gal9) and tumor-infiltrating lymphocyte (TIL) markers was assessed by immunohistochemistry. Kaplan-Meier and multivariate Cox analyses were used to assessing local recurrence-free survival (LRFS) and overall survival (OS) of patients. MiR-455-5p was identified as a regulator of Gal9 expression. Immunopositivity for Gal9 was associated with tumor invasion (p = 0.019), Karnofsky performance status (KPS) score (p = 0.017), and total TIL count (p < 0.001); downregulation of miR-455-5p was correlated with tumor invasion (p = 0.017) and poor prognosis; and the T-cell immunoglobulin and mucin-domain 3 (TIM3)+ TIL count was associated with chordoma invasion (p = 0.010) and KPS score (p = 0.037). Furthermore, multivariate analysis indicated that only TIM3+ TIL density was an independent prognostic factor for LRFS (p = 0.010) and OS (p = 0.016). These results can be used to predict clinical outcome and provide a basis for immune therapy in skull base chordoma patients.

LncRNA MCM3AP-AS1 Regulates Epidermal Growth Factor Receptor and Autophagy to Promote Hepatocellular Carcinoma Metastasis by Interacting with miR-455

Hepatocellular carcinoma (HCC) has been reported to be one of the major tumors in the world. There is a study indicating that MCM3AP-AS1 is an oncogenic factor in HCC; however, the mechanism by which MCM3AP-AS1 regulates HCC remains not fully understood. Reverse Transcription-quantitative PCR and Western blot approaches were used to detect mRNA and protein levels of various genes. To examine invasion of HCC cells and lymphatic vessel formation of human dermal lymphatic endothelial cells (HDLECs), we employed transwell invasion assay and lymphatic vessel assay. Bioinformatic analysis and luciferase reporter assay were used to establish direct interactions between MCM3AP-AS1 and miR-455. Besides, The Cancer Genome Atlas analyses of HCCs were performed to determine the association of MCM3AP-AS1 and epidermal growth factor receptor (EGFR) with overall survival. MCM3AP-AS1 knockdown impaired invasion of HCC cells and lymphatic vessel formation of HDLECs. MCM3AP-AS1 directly interacted with miR-455. Furthermore, miR-455 inhibitor-transfected HepG2 cells enhanced the invasion and lymphatic vessel formation abilities. The rescue experiments indicated that EGFR was critical for MCM3AP-AS1- and miR-455-regulated invasion and lymphatic vessel formation. More interestingly, autophagy-related genes (Beclin1, LC3 II/I, and ATG7) were abnormally regulated in miR-455 mimic or inhibitor HepG2 cells. miR-455 mimic inhibited cell invasion and lymphatic vessel formation, which was evidently abrogated by ATG7 overexpression. Finally, we analyzed The Cancer Genome Atlas data sets to test the upregulated expression levels of MCM3AP-AS1 and EGFR. In addition, the results showed that low levels of both genes facilitate survival of HCC patients. In this study, we reveal a novel mechanism underlying MCM3AP-AS1-induced HCC metastasis by regulating miR-455. The conclusions provide more insights into understanding mechanism underlying HCC and help development of therapeutical approaches for treating HCC.

MiR-455-5p Suppresses the Progression of Prostate Cancer by Targeting CCR5

Accumulated evidence indicates that miR-455-5p functions as tumor suppressor in the progression of various cancers. However, the mechanism through which miR-455-5p influences the tumorigenesis of human prostate cancer (PCa) remains undetermined. In this study, reanalysis of data obtained from the Memorial Sloan Kettering Cancer Center showed that miR-455-5p can be used as biomarker for PCa diagnosis and predictor of poor prognosis. Functional assays indicated that miR-455-5p overexpression could suppress cellular proliferation, inhibit tumor growth, and trigger apoptosis by activating and cleaving caspase 3. We experimentally verified that miR-455-5p negatively regulated the C–C motif chemokine receptor 5 (CCR5). Overall, our data demonstrate that miR-455-5p suppressed PCa cellular proliferation and induced cell apoptosis by downregulating CCR5. Thus, miR-455-5p may be considered a new therapeutic strategy for PCa.

The heterogeneity of plasma miRNA profiles in hepatocellular carcinoma patients and the exploration of diagnostic circulating miRNAs for hepatocellular carcinoma

Heterogeneity is prevalent in cancer both between and within individuals. Although a few studies have identified several circulating microRNAs (miRNAs) for cancer diagnosis, the complete plasma miRNA profile for hepatocellular carcinoma (HCC) remains undefined, and whether the plasma miRNA profiles are heterogeneous is unknown. Here, we obtained individualized plasma miRNA profiles of both healthy subjects and HCC patients via genome-wide deep sequencing. Compared with the highly stable miRNA profile of the healthy subjects, the profile of the HCC patients was highly variable. Seven miRNAs were optimized as potential plasma-based biomarkers for HCC diagnosis. Combined with the clinical data of The Cancer Genome Atlas (TCGA) cohort, three out of the seven miRNAs were correlated with the survival of the HCC patients. To investigate the effect of cancer cells on the plasma miRNAs profile, we compared the most differentially expressed miRNAs between plasma and tissues. Furthermore, miRNAseq data of HCC patients from TCGA were recruited for comparisons. We found that the differences between plasma and tissue were inconsistent, suggesting that other cells in addition to cancer cells also contribute to plasma miRNAs. Using two HCC cancer cell lines, we examined the levels of seven differentially expressed miRNAs. The reverse direction of certain miRNAs alterations between cancer cells and media further confirmed that miRNAs may be selectively pump out by cancer cells.

Pirin: a potential novel therapeutic target for castration-resistant prostate cancer regulated by miR-455-5p

Androgen deprivation therapy is frequently used to treat prostate cancer (PCa), but resistance can occur, a condition known as castration‐resistant prostate cancer (CRPC). Thus, novel approaches for identification of CRPC are important for designing effective PCa treatments. Analysis of microRNA (miRNA) expression signatures by RNA sequencing showed that both passenger and guide strands of the miR‐455‐duplex (miR‐455‐5p and miR‐455‐3p, respectively) acted as antitumor miRNAs in PCa cells. The involvement of miRNA passenger strands in cancer pathogenesis is a novel concept for miRNA functionality. Based on a large patient cohort in The Cancer Genome Atlas, expression of eight miR‐455‐5p/‐3p target genes (PIR: P = 0.0137, LRP8: P = 0.0495, IGFBP3: P = 0.0172, DMBX1: P = 0.0175, CCDC64: P = 0.0446, TUBB1: P = 0.0149, KIF21B: P = 0.0336, and NFAM1: P = 0.0013) was significantly associated with poor prognosis of PCa patients. Here, we focused on PIR (pirin), a highly conserved member of the cupin superfamily. PIR expression was directly regulated by miR‐455‐5p, and PIR overexpression was detected in hormone‐sensitive prostate cancer (HSPC) surgical specimens and CRPC autopsy specimens. Loss‐of‐function assays using siRNA or an inhibitor (bisamide) showed that downregulation of PIR expression blocked cancer cell migration and invasion. Moreover, the miR‐455‐5p/PIR axis contributed to cancer cell aggressiveness. These results suggest that PIR might be a promising diagnostic marker for HSPC and CRPC. Furthermore, CRPC treatment strategies targeting PIR may be possible in the future. Identification of antitumor miRNAs, including miRNA passenger strands, may contribute to the development of new diagnostic markers and therapeutic strategies for CRPC.

Expression profile and biological function of miR-455-5p in colorectal carcinoma

Underexpression of microRNA-455-5p (miR-455-5p) in medullary thyroid carcinoma, melanoma, gastric cancer and additional cancer types has been reported, which may be associated with carcinoma development. The present study aimed to evaluate the expression profile and biological role of miR-455-5p in colorectal carcinoma. Carcinoma tissues and adjacent tissue specimens from 40 patients with colorectal cancer were randomly collected. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was conducted to detect the expression levels of miR-455-5p in colorectal carcinoma and adjacent normal tissues. The biological effects of miR-455-5p on selected colorectal cancer cells were assessed using bromodeoxyuridine assays, wound healing migration assays and flow cytometry. Bioinformatics analysis was implemented to predict the potential target genes of miR-455-5p in colorectal cancer. The expression levels of target genes were further validated by RT-qPCR and western blot analysis of the mRNA and protein levels. The results of the experiments demonstrated that miR-455-5p expression was downregulated in colorectal cancer tissues compared with adjacent normal tissues. In colorectal cancer cells (SW-480, HT-29 and HCT-116), miR-455-5p was observed to inhibit cell proliferation and migration while promoting cell apoptosis. Bioinformatics analysis predicted that the oncogene phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) was one of the top ranked target genes of miR-455-5p in colorectal cancer cells. This association was validated by RT-qPCR and western blotting. In vivo studies revealed that the expression level of miR-455-5p was significantly downregulated in human colorectal cancer. Further in vitro studies suggested that miR-455-5p may prevent the development of colorectal cancer by downregulating the oncogene PIK3R1. It was concluded that miR-455-5p may target and downregulate PIK3R1 in colorectal cancer.

Inhibitory effect of microRNA-455-5p on biological functions of esophageal squamous cell carcinoma Eca109 cells via Rab31

The aim of the present study was to examine microRNA (miRNA or miR)-455-5p expression in esophageal squamous cell carcinoma (ESCC) at the tissue and cellular levels in order to elucidate its biological roles. A total of 60 patients with ESCC were enrolled in the present study and reverse transcription-quantitative polymerase chain reaction was used to measure the expression of miR-455-5p. ESCC Eca109 cells were transfected with miR-NC, miR-455-5p mimics or inhibitor and a Cell Counting Kit-8 assay was used to assess proliferation. To investigate the migration and invasion abilities of Eca109 cells, Transwell and Matrigel assays were performed. Western blotting was employed to measure Rab31 protein expression, while a rescue assay was utilized to study the biological roles of miR-455-5p and Rab31 in Eca109 cells. To determine whether Rab31 is a direct target of miR-455-5p, a dual luciferase reporter assay was performed. The results revealed that miR-455-5p expression was decreased in ESCC tissues and was negatively correlated with metastasis and pathogenesis. In vitro overexpression of miR-455-5p inhibited the proliferation, migration and invasion of ESCC Eca109 cells. Furthermore, miR-455-5p regulated the expression of Rab31 protein in Eca109 cells. Rab31 overexpression promoted the proliferation, migration and invasion of Eca109 cells. Luciferase reporter assay results revealed that miR-455-5p is able to bind with the 3'-untranslated region of Rab31 mRNA to regulate its expression. In summary, the results of the present study suggest that miR-455-5p expression is decreased in ESCC tissues and is miR-455-5p is negatively correlated with lymphatic metastasis and differentiation. As a tumor-suppressor gene, miR-455-5p inhibits the proliferation, migration and invasion of ESCC Eca109 cells by suppressing the expression of Rab31.

Rab18 overexpression promotes proliferation and chemoresistance through regulation of mitochondrial function in human gastric cancer

Background

Dysregulation of Rab18 has been implicated in human cancers. However, its clinical significance and biological function in gastric cancer have not been investigated.

Methods

We examined Rab18 expression in gastric cancer tissues using immunohistochemistry. We used SNU-1 and AGS cell lines for plasmid and siRNA transfection respectively. MTT, colony formation assay, cell cycle analysis, matrigel invasion, wound healing assay, AnnexinV/PI analysis and western blotting were used to examine the biological effect and mechanism of Rab18 in gastric cancer cell lines.

Results

Rab18 protein expression was upregulated in gastric cancer tissues and this correlated with advanced stage and poor prognosis. Rab18 overexpression promoted proliferation in vitro and in vivo. Cell cycle analysis showed that Rab18 overexpression upregulated, while its depletion downregulated S phase percentage. Matrigel invasion and wound healing assays indicated that Rab18 positively regulated SNU-1 cell invasion and migration while its knockdown inhibited AGS cell invasion and migration. Rab18 maintained cell viability and downregulated apoptosis after cisplatin treatment, with upregulated mitochondrial membrane potential and downregulated mitochondrial reactive oxygen species (ROS) production. Rab18 overexpression upregulated p-Rb, survivin while downregulated cytochrome c, cleaved caspase-3 and cleaved PARP.

Conclusion

In conclusion, our results indicate that Rab18 promoted gastric cancer growth and chemoresistance, possibly through regulation of mitochondrial function and survivin.

Promotion of Cell Proliferation through Inhibition of Cell Autophagy Signalling Pathway by Rab3IP is Restrained by MicroRNA-532-3p in Gastric Cancer

Background: RAB3A-interacting protein (Rab3IP) is known to be involved in cancer; however, its function during the proliferation of gastric cancer (GC) cells remains unknown. Therefore, this study aimed to explore the potential function of Rab3IP in GC. Methods: The expression of Rab3IP and its clinical pathology value were determined by quantitative real-time PCR and immunohistochemistry. Rab3IP (knockdown and overexpression) and light chain 3 (LC3) lentiviruses were transfected into GC cells, and cell proliferation was measured using cell counting kit-8, plate clone formation, flow cytometry, and tumorigenesis assays. Cell autophagy was measured using a confocal laser scanning microscope and by western blotting. Luciferase reporter assay was performed to analyse the regulation of Rab3IP by microRNA-532-3p (miR-532-3p). Results: Overexpression of Rab3IP in GC samples enhanced the cell proliferation ability, but decreased the number of autophagosomes and expression of LC3-II and sequestosome-1 (SQSTM1 or p62) markers. Furthermore, we found that miR-532-3p can bind to the 3'UTR region of RAB3IP and inhibit the proliferation ability of GC cells. Further, the expression of miR-532-3p negatively correlated with that of Rab3IP. Conclusions: Our study elucidates the central role of Rab3IP in inducing proliferation of GC cells through its involvement in autophagy. miR-532-3p directly targets Rab3IP and represses its function, thereby demonstrating a novel regulatory link in GC.

Integration of miRNA and mRNA Co-Expression Reveals Potential Regulatory Roles of miRNAs in Developmental and Immunological Processes in Calf Ileum during Early Growth

This study aimed to investigate the potential regulatory roles of miRNAs in calf ileum developmental transition from the pre- to the post-weaning period. For this purpose, ileum tissues were collected from eight calves at the pre-weaning period and another eight calves at the post-weaning period and miRNA expression characterized by miRNA sequencing, followed by functional analyses. A total of 388 miRNAs, including 81 novel miRNAs, were identified. A total of 220 miRNAs were differentially expressed (DE) between the two periods. The potential functions of DE miRNAs in ileum development were supported by significant enrichment of their target genes in gene ontology terms related to metabolic processes and transcription factor activities or pathways related to metabolism (peroxisomes), vitamin digestion and absorption, lipid and protein metabolism, as well as intracellular signaling. Integration of DE miRNAs and DE mRNAs revealed several DE miRNA-mRNA pairs with crucial roles in ileum development (bta-miR-374a-FBXO18, bta-miR-374a-GTPBP3, bta-miR-374a-GNB2) and immune function (bta-miR-15b-IKBKB). This is the first integrated miRNA-mRNA analysis exploring the potential roles of miRNAs in calf ileum growth and development during early life.

Expression profiles of stemness genes in gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is believed to originate from intestinal cells of Cajal or their stem cell precursors, and expresses stemness-related markers, such as CD117, CD34, DOG1 and nestin. To further characterize phenotypic features of GISTs, we examined expression profiles of a panel of stemness genes in GISTs, by analyzing existing gene expression profiling datasets. Our results showed that mRNA levels of B-lymphoma moloney murine leukaemia virus insertion region-1 (BMI1), kruppel-like factor 4 (KLF4), sal-like protein 4 (SALL4) and telomerase reverse transcriptase (TERT) were significantly unregulated in GISTs. Subsequently, protein expression of BMI1 and TERT was identified in GIST specimens by immunohistochemistry. Especially, we found that high expression of nuclear BMI1 was associated with large tumor size (P = .0239), high mitotic count (P < .01), high Ki-67 index (P = .0357), advanced National Institute of Health (NIH) criteria (P = .0025) and advanced World Health Organization (WHO) classification (P < .01) in GISTs. Functional and pathway enrichment analysis showed that most of BMI1's coexpressed genes were involved in tumor growth-related process, such as regulation of cell cycle and proliferation. Furthermore, we confirmed RAS oncogene family (RAB18) and limb development membrane protein 1 (LMBR1) genes as novel targets for BMI1 in GIST cells. These results provide valuable information for the expression profiles of stemness genes in GISTs, and identified nuclear BMI1 as an important marker of GIST cell proliferation and progression.

MicroRNA-455-3p as a Potential Biomarker for Alzheimer's Disease: An Update

A non-invasive and early-detectable peripheral biomarker is urgently needed for Alzheimer's disease (AD). The present study is a step forward to verify the biomarker properties of human microRNA-455-3p (Hsa-miR-455-3p) in AD patients. Our previous findings on mild cognitive impaired subjects, AD patients and AD cells and mouse models unveiled the miR-455-3p as a potential peripheral biomarker for AD. In the current study, we verified the differential expression of miR-455-3p in postmortem AD brains obtained from NIH NeuroBioBank, and fibroblasts and B-lymphocytes from both familial and sporadic AD patients from Coriell Cell Repository of National Institutes on Aging. Total RNA was extracted from the fibroblasts, B-lymphocytes and AD postmortem brains, and expression of miR-455-3p was measured by real-time reverse-transcriptase RT-PCR. Our real-time RT-PCR analysis showed a significant (P = 0.0002) upregulation of miR-455-3p expression in AD postmortem brains compared to healthy control samples. Expression of miR-455-3p was also upregulated in the fibroblasts from AD patients, however a significant difference in miR-455-3p level was observed in the cells from sporadic AD patients (P = 0.014) compared to healthy controls. Similarly, in B-lymphocytes, miR-455-3p level was also higher (P = 0.044) especially in sporadic AD cases compared to controls. Receiver operating characteristic (ROC) curve analysis indicated the significant area under ROC curve (AUROC) value of miR-455-3p in AD postmortem brain (AUROC = 0.792; P = 0.001) and AD fibroblasts cells (AUROC = 0.861; P = 0.03), whereas in B-lymphocytes AUROC value of miR-455-3p was not significant. Further, in-silico analysis for miRNA targets predictions showed the binding capacity of miR-455-3p with several AD associated key genes such as APP, NGF, USP25, PDRG1, SMAD4, UBQLN1, SMAD2, TP73, VAMP2, HSPBAP1, and NRXN1. Hence, these observations further revealed that miR-455-3p is a potential biomarker for AD and its possible therapeutic target for AD.

Characteristic miRNA expression signature and random forest survival analysis identify potential cancer-driving miRNAs in a broad range of head and neck squamous cell carcinoma subtypes

AIM

To characterize the miRNA expression profile in head and neck squamous cell carcinoma (HNSSC) accounting for a broad range of cancer subtypes and consequently identify an optimal miRNA signature with prognostic value.

BACKGROUND

HNSCC is consistently among the most common cancers worldwide. Its mortality rate is about 50% because of the characteristic aggressive behavior of these cancers and the prevalent late diagnosis. The heterogeneity of the disease has hampered the development of robust prognostic tools with broad clinical utility.

MATERIALS AND METHODS

The Cancer Genome Atlas HNSC dataset was used to analyze level 3 miRNA-Seq data from 497 HNSCC patients. Differential expression (DE) analysis was implemented using the limma package and multivariate linear model that adjusted for the confounding effects of age at diagnosis, gender, race, alcohol history, anatomic neoplasm subdivision, pathologic stage, T and N stages, and vital status. Random forest (RF) for survival analysis was implemented using the randomForestSRC package.

RESULTS

A characteristic DE miRNA signature of HNSCC, comprised of 11 upregulated (i.e., miR-196b-5p, miR-1269a, miR-196a-5p, miR-4652-3p, miR-210-3p, miR-1293, miR-615-3p, miR-503-5p, miR-455-3p, miR-205-5p, and miR-21-5p) and 9 downregulated (miR-376c-3p, miR-378c, miR-29c-3p, miR-101-3p, miR-195-5p, miR-299-5p, miR-139-5p, miR-6510-3p, miR-375) miRNAs was identified. An optimal RF survival model was built from seven variables including age at diagnosis, miR-378c, miR-6510-3p, stage N, pathologic stage, gender, and race (listed in order of variable importance).

CONCLUSIONS

The joint differential miRNA expression and survival analysis controlling for multiple confounding covariates implemented in this study allowed for the identification of a previously undetected prognostic miRNA signature characteristic of a broad range of HNSCC.

Downregulation of MicroRNA-455-3p Links to Proliferation and Drug Resistance of Pancreatic Cancer Cells via Targeting TAZ

Drug resistance is a major cause of treatment failure in pancreatic cancer. The limited evidence indicates the involvement of miR-455-3p in chemotherapy resistance of cancer. Here we observed by qPCR that miR-455-3p was significantly decreased in pancreatic cancer tissues and cell lines. We then confirmed that the inhibition of miR-455-3p increased cell proliferation and gemcitabine resistance of pancreatic cancer, whereas forced overexpression of miR-455-3p had the opposite effect. Furthermore, we demonstrated that TAZ, which is associated with drug resistance of pancreatic cancer, is a new direct downstream target of miR-455-3p. Our present study suggests that miR-455-3p contributes to cell proliferation and drug resistance in pancreatic cancer cells via targeting TAZ.

miR‑455‑5p promotes cell invasion and migration in breast cancer

MicroRNA (miR)‑455‑5p has been identified as a biomarker for various types of cancer and may therefore be involved in the regulation of cancer development and progression. However, the specific role and function of miR‑455‑5p in breast cancer remains unclear. The present study explored the expression levels and function of miR‑455‑5p in breast cancer. The results from reverse transcription‑quantitative polymerase chain reaction analysis revealed that miR‑455‑5p was significantly upregulated in breast cancer. Clinically, increased expression of miR‑455‑5p predicted a poor survival rate and miR‑455‑5p was identified as one of the independent prognostic factors for breast cancer patients. Furthermore, results from wound healing and Transwell assays revealed that miR‑455‑5p accelerated invasiveness and migration capabilities of breast cancer cells. In addition, programmed cell death 4 was identified as a downstream target of miR‑455‑5p and its expression was observed to be negatively regulated by miR‑455‑5p. Overall, miR‑455‑5p may function as an oncogene in breast cancer, and may therefore be used as a prognostic marker for breast cancer patients.

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

BACKGROUND

Previous articles have reported that expression levels of microRNAs (miRNAs) are associated with survival time of patients with gastric cancer (GC). A systematic review and meta-analysis was performed to study the outcome of it.

DESIGN

Meta-analysis.

METHODS

English studies estimating expression levels of miRNAs with any of survival curves in GC were identified up till March 19, 2017 through performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two authors independently. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

RESULTS

Sixty-nine relevant articles about 26 miRNAs with 6148 patients were ultimately included. GC patients with high expression of miR-20b (HR=2.38, 95%CI=1.16-4.87), 21 (HR=1.77, 95%CI=1.01-3.08), 106b (HR=1.84, 95%CI=1.15-2.94), 196a (HR=2.66, 95%CI=1.94-3.63), 196b (HR=1.67, 95%CI=1.38-2.02), 214 (HR=1.84, 95%CI=1.27-2.67) or low expression of miR-125a (HR=2.06, 95%CI=1.26-3.37), 137 (HR=3.21, 95%CI=1.68-6.13), 141 (HR=2.47, 95%CI=1.34-4.56), 145 (HR=1.62, 95%CI=1.07-2.46), 146a (HR=2.60, 95%CI=1.63-4.13), 206 (HR=2.85, 95%CI=1.73-4.70), 218 (HR=2.61, 95%CI=1.74-3.92), 451 (HR=1.73, 95%CI=1.19-2.52), 486-5p (HR=2.45, 95%CI=1.65-3.65), 506 (HR=2.07, 95%CI=1.33-3.23) have significantly poor OS (P<0.05).

CONCLUSIONS

In summary, miR-20b, 21, 106b, 125a, 137, 141, 145, 146a, 196a, 196b, 206, 214, 218, 451, 486-5p and 506 demonstrate significantly prognostic value. Among them, miR-20b, 125a, 137, 141, 146a, 196a, 206, 218, 486-5p and 506 are strong biomarkers of prognosis in GC.