miR-23a acts as an oncogene in pancreatic carcinoma by targeting FOXP2

Down-regulation of microRNA-23a promotes pancreatic ductal adenocarcinoma initiation and progression by up-regulation of FOXM1 expression

Transcriptional factor Forkhead box M1 (FOXM1) plays an important role in pancreatic ductal adenocarcinoma (PDAC) development and progression. The molecular mechanisms underlying its dysregulation remain unclear. We identified and functionally validated the microRNAs (miRNAs) that critically regulate FOXM1 expression in PDAC. The expression levels of miRNA-23a (miR-23a-3p and -5p) were altered in PDAC cell lines and their effects on FOXM1 signaling and cell proliferation and migration and tumorigenesis were examined in vitro and in vivo using mouse PDAC models. Compared with non-tumor pancreatic tissues, PDAC tissues and cell lines exhibited significantly reduced levels of miR-23a expression. Reduced miR-23a expression and concomitant increase in FOXM1 expression were also observed in acinar-to-ductal metaplasia and pancreatic intraepithelial neoplasia, the major premalignant lesions of PDAC. Transgenic expression of miR-23a reduced the expression of FOXM1 and suppressed cell proliferation and migration in PDAC cells, whereas the inhibitors of miR-23a did the opposite. Loss or reduced levels of miR-23a increased the levels of FOXM1 expression, while increased expression of FOXM1 down-regulated miR-23a expression, suggesting that miR-23a and FOXM1 were mutual negative regulators of their expression in PDAC cells. Therefore, the miR-23a/FOXM1 signaling axis is important in PDAC initiation and progression and could serve as an interventional or therapeutic target for patients with early or late stages of PDAC.

Functional and Potential Therapeutic Implication of MicroRNAs in Pancreatic Cancer

The alarmingly low five-year survival rate for pancreatic cancer presents a global health challenge, contributing to about 7% of all cancer-related deaths. Late-stage diagnosis and high heterogeneity are the biggest hurdles in treating pancreatic cancer. Thus, there is a pressing need to discover novel biomarkers that could help in early detection as well as improve therapeutic strategies. MicroRNAs (miRNAs), a class of short non-coding RNA, have emerged as promising candidates with regard to both diagnostics and therapeutics. Dysregulated miRNAs play pivotal roles in accelerating tumor growth and metastasis, orchestrating tumor microenvironment, and conferring chemoresistance in pancreatic cancer. The differential expression profiles of miRNAs in pancreatic cancer could be utilized to explore novel therapeutic strategies. In this review, we also covered studies on recent advancements in various miRNA-based therapeutics such as restoring miRNAs with a tumor-suppressive function, suppressing miRNA with an oncogenic function, and combination with chemotherapeutic drugs. Despite several challenges in terms of specificity and targeted delivery, miRNA-based therapies hold the potential to revolutionize the treatment of pancreatic cancer by simultaneously targeting multiple signaling pathways.

DNASE1L3 regulation by transcription factor FOXP2 affects the proliferation, migration, invasion and tube formation of lung adenocarcinoma

Lung adenocarcinoma (LUAD) is prone to bone metastasis, resulting in poor prognosis. The present study aimed to detect the expression of deoxyribonuclease 1-like 3 (DNASE1L3) and forkhead-box P2 (FOXP2) in LUAD cells to investigate the role of DNASE1L3 in the regulation of proliferation, migration, invasion and tube formation of LUAD cells and how FOXP2 affects DNASE1L3 expression. The expression of DNASE1L3 and FOXP2 in LUAD cells was analyzed by reverse transcription-quantitative PCR (RT-qPCR) and western blotting. The transfection efficiency of DNASE1L3 overexpression plasmids, FOXP2 overexpression or interference plasmids into A549 cells was also confirmed by RT-qPCR and western blotting. The viability, proliferation, migration and invasion and tube formation of LUAD cells following transfection was in turn detected by MTT, EdU staining, wound healing, Transwell and tube formation assay. The expression of proteins associated with epithelial-mesenchymal transformation and tube formation was detected by western blotting. Binding between DNASE1L3 and FOXP2 was confirmed by dual-luciferase reporter assay and chromatin immunoprecipitation. Gene Expression Profiling Interactive Analysis database predicted that underexpression of DNASE1L3 in LUAD was associated with poor prognosis. DNASE1L3 expression was decreased in LUAD cells and overexpression of DNASE1L3 inhibited the proliferation, migration, invasion and tube formation of LUAD cells. Transcription factor FOXP2 positively regulated DNASE1L3 transcription in LUAD cells. FOXP2 was also underexpressed in LUAD cells and downregulation of FOXP2 promoted proliferation, migration, invasion and tube formation of LUAD cells, which was reversed by overexpression of DNASE1L3. In conclusion, DNASE1L3 was positively regulated by transcription factor FOXP2 and overexpression inhibited proliferation, migration, invasion and tube formation of LUAD cells.

Thioredoxin System and miR-21, miR-23a/b and let-7a as Potential Biomarkers for Brain Tumor Progression: Preliminary Case Data

BACKGROUND

The thioredoxin system and microRNAs (miRNAs) are potential targets for both cancer progression and treatment. However, the role of miRNAs and their relation with the expression profile of thioredoxin system in brain tumor progression remains unclear.

METHODS

In this study, we aimed to determine the expression profiles of redox components Trx-1, TrxR-1 and PRDX-1, and oncogenic miR-21, miR-23a/b and let-7a and oncosuppressor miR-125 in different brain tumor tissues and their association with increasing tumor grade. We studied Trx-1, TrxR-1, and PRDX-1 messenger RNA expression levels by quantitative real-time polymerase chain reaction and protein levels by Western blot and miR-23a, miR-23b, miR-125a, miR-21, and let-7a miRNA expression levels by quantitative real-time polymerase chain reaction in 16 glioma, 15 meningioma, 5 metastatic, and 2 benign tumor samples. We also examined Trx-1, TrxR-1, and PRDX-1 protein levels in serum samples of 36 patients with brain tumor and 37 healthy volunteers by enzyme-linked immunosorbent assay.

RESULTS

We found that Trx-1, TrxR-1, and PRDX-1 presented high messenger RNA expression but low protein expression in low-grade brain tumor tissues, whereas they showed higher protein expression in sera of patients with low-grade brain tumors. miR-23b, miR-21, miR-23a, and let-7a were highly expressed in low-grade brain tumor tissues and positively correlated with the increase in thioredoxin system activity.

CONCLUSIONS

Our findings showed that Trx-1, TrxR-1, miR-21, miR-23a/b, and let-7a might be used for brain tumor diagnosis in the clinic. Further prospective studies including molecular pathway analyses are required to validate the miRNA/Trx system regulatory axis in brain tumor progression.

FOXP2 regulates thyroid cancer cell proliferation and apoptosis via transcriptional activation of RPS6KA6

The transcription factor, forkhead box P2 (FOXP2) has tumor-suppressive effects in several types of cancer. However, the regulatory role and underlying mechanism of FOXP2 in thyroid cancer (THCA) is not completely understood. In the present study, the mRNA expression levels of FOXP2 and ribosomal protein S6 kinase A6 (RPS6KA6) were evaluated using the GEPIA database and THCA cell lines. The association between FOXP2 and RPS6KA6 was analyzed using the LinkedOmics, and GEPIA databases. Then, the binding sites of FOXP2 and the RPS6KA6 promotor was predicted using the JASPAR database, and verified using a dual-luciferase reporter assay and chromatin immunoprecipitation. In addition, functional assays investigating FOXP2 and RPS6KA6 were conducted in the TPC-1 cell line. The data showed that FOXP2 and RPS6KA6 mRNA expression levels were decreased in the THCA tissues, and cell lines. Overexpression of FOXP2 inhibited cell proliferation and promoted apoptosis in the THCA cell lines. Furthermore, RPS6KA6 mRNA expression levels were reduced in THCA and were correlated with FOXP2 expression level. Mechanistic studies revealed that FOXP2 binds directly to the promotor region of RPS6KA6 and modulated the expression level of RPS6KA6 transcriptionally. In addition, rescue experiments showed that knockdown of RPS6KA6 expression reversed the effects of FOXP2 overexpression on THCA cell proliferation and apoptosis, and the regulation of FOXP2/RPS6KA6 may be associated with the PI3K/AKT pathway. In summary, FOXP2 was associated with the proliferation and apoptosis of human THCA cells via the transcriptional activation of RPS6KA6. The FOXP2/RPS6KA6 axis could be a promising target for the treatment of THCA.

MiR-142-5p serves as a tumor suppressor in retinoblastoma cells by regulating MYCN

Retinoblastoma is an intraocular malignant tumor and generally occurred in childhood. Here, we intended to appraise the functional influence of microRNA-142-5p (miR-142-5p) in retinoblastoma. MiR-142-5p was declined, and MYCN was upregulated in retinoblastoma tissues and cells. Moreover, miR-142-5p restricted cell proliferation, migration, invasion, and enhanced cell apoptosis in retinoblastoma cells. MYCN was adversely controlled by miR-142-5p. Besides, the inhibition of miR-142-5p-mediated effects on retinoblastoma progression were blocked by MYCN overexpression in retinoblastoma cells. This research illustrated that miR-142-5p restricted retinoblastoma progression via interacting with MYCN.

The Circular RNA circXPO1 Promotes Tumor Growth via Sponging MicroRNA-23a in Prostate Carcinoma

It has been shown that circular RNA XPO1 (circXPO1) is involved in cancer (e.g., lung adenocarcinoma and osteosarcoma) progression by sponging microRNAs. Nevertheless, the role of circXPO1 and its interaction with microRNAs in prostate cancer remains unknown. In this study, the results of quantitative real-time PCR showed that circXPO1 levels were dramatically increased in human prostate cancer tissue and cell lines compared with those in normal tissue and cell line. Furthermore, cell proliferation, colony formation, and cell invasion assays showed that circXPO1 promoted the malignant behavior of pancreatic cells in vitro. Mechanistically, bioinformatics prediction, a dual-luciferase reporter assay, and pull-down assay suggested that circXPO1 physically targets miR-23a and negatively regulates its expression in pancreatic cancer cells. miR-23a mimics and inhibitors effectively reversed the effects of circXPO1 on the malignant behavior of prostate cancer cells in vitro. Consistent results were observed in the xenograft tumor model. In conclusion, circXPO1 promotes prostate cancer progression via targeting miR-23a, thus suggesting the circXPO1/miR-23a axis can be used as a potential therapeutic target for prostate cancer treatment.

Bioinformatics analysis of dysregulated exosomal microRNAs derived from oral squamous cell carcinoma cells

PURPOSE

The present study aimed to identify dysregulated exosomal miRNAs associated with diagnostic and therapeutic biomarkers in oral squamous cell carcinoma (OSCC).

METHODS

Microarray analysis was used to compare expression profiles of exosomal miRNAs in the OSCC-derived cell lines HSC-2, HSC-3, Ca9-22, and HO-1-N1 with those in human normal keratinocytes (HNOKs). The identified OSCC-related miRNAs and their potential target genes were analyzed with bioinformatic analyses, and the data were subjected to Ingenuity Pathway Analysis (IPA) to clarify functional networks and gene ontologies of the identified exosomal miRNAs secreted by OSCC cells.

RESULTS

Comparison with HNOKs detected 8 upregulated and 12 downregulated miRNAs in OSCC-secreted exosomes. The potential target mRNAs of these dysregulated miRNAs were suggested by IPA, and 6 significant genetic networks were indicated by genetic network analysis. Furthermore, 4 crucial upstream miRNAs-miR-125b-5p, miR-17-5p, miR-200b-3p, and miR-23a-3p-were identified. miR-125b-5p was a central node in the most significant network. Gene ontology analysis showed significant enrichment of genes with cancer-related functions, such as molecular mechanisms of cancer, cell cycle, and regulation of the epithelial-mesenchymal transition.

CONCLUSION

These results provide a comprehensive view of the functions of dysregulated exosomal miRNAs in OSCC, thus illuminating OSCC tumorigenesis and development.

Low concentration of Bupivacaine ameliorates painful diabetic neuropathy by mediating miR-23a/PDE4B axis in microglia

Bupivacaine (Bup) has a certain research basis in pain-related diseases, but it has not been studied in painful diabetic neuropathy. In this study, we investigated the role of Bupivacaine in painful diabetic neuropathy. Mouse model with painful diabetic neuropathy was established, and then treated with different concentrations of Bupivacaine. The blood glucose level in the tail vein and the changes in body weight was measured. The mechanical allodynia, thermal hyperalgesia and thermal allodynia was assessed by pain behavioral tests. Microglia were treated with high glucose (HG) and different concentrations of Bupivacaine. The levels of inflammatory cytokines were detected by using Enzyme-linked immunosorbent assays. Dual luciferase reporter assay explored the relationship between miR-23a and phosphodiesterase 4 B (PDE4B). The results displayed that Bupivacaine ameliorated the mechanical allodynia, thermal hyperalgesia, and thermal allodynia in mice with painful diabetic neuropathy, and is more effective at low concentration. Moreover, low concentration of Bupivacaine inhibited inflammation and promoted miR-23a expression in mice with painful diabetic neuropathy and in microglia induced by HIGH GLUCOSE. Overexpression of miR-23a reduced the levels of inflammatory cytokines by down-regulating PDE4B expression. Knockdown of miR-23a reversed the inhibition effect of Bupivacaine on microglial inflammation. These results revealed that low concentration of Bupivacaine inhibited microglial inflammation through down-regulating PDE4B via miR-23a, thereby attenuated painful diabetic neuropathy.

Use of signals of positive and negative selection to distinguish cancer genes and passenger genes

A major goal of cancer genomics is to identify all genes that play critical roles in carcinogenesis. Most approaches focused on genes positively selected for mutations that drive carcinogenesis and neglected the role of negative selection. Some studies have actually concluded that negative selection has no role in cancer evolution. We have re-examined the role of negative selection in tumor evolution through the analysis of the patterns of somatic mutations affecting the coding sequences of human genes. Our analyses have confirmed that tumor suppressor genes are positively selected for inactivating mutations, oncogenes, however, were found to display signals of both negative selection for inactivating mutations and positive selection for activating mutations. Significantly, we have identified numerous human genes that show signs of strong negative selection during tumor evolution, suggesting that their functional integrity is essential for the growth and survival of tumor cells.

Knockdown of lncRNA MALAT1 Alleviates LPS-Induced Acute Lung Injury via Inhibiting Apoptosis Through the miR-194-5p/FOXP2 Axis

Purpose

We aimed to identify and verify the key genes and lncRNAs associated with acute lung injury (ALI) and explore the pathogenesis of ALI. Research showed that lower expression of the lncRNA metastasis-associated lung carcinoma transcript 1 (MALAT1) alleviates lung injury induced by lipopolysaccharide (LPS). Nevertheless, the mechanisms of MALAT1 on cellular apoptosis remain unclear in LPS-stimulated ALI. We investigated the mechanism of MALAT1 in modulating the apoptosis of LPS-induced human pulmonary alveolar epithelial cells (HPAEpiC).

Methods

Differentially expressed lncRNAs between the ALI samples and normal controls were identified using gene expression profiles. ALI-related genes were determined by the overlap of differentially expressed genes (DEGs), genes correlated with lung, genes correlated with key lncRNAs, and genes sharing significantly high proportions of microRNA targets with MALAT1. Quantitative real-time PCR (qPCR) was applied to detect the expression of MALAT1, microRNA (miR)-194-5p, and forkhead box P2 (FOXP2) mRNA in 1 μg/ml LPS-treated HPAEpiC. MALAT1 knockdown vectors, miR-194-5p inhibitors, and ov-FOXP2 were constructed and used to transfect HPAEpiC. The influence of MALAT1 knockdown on LPS-induced HPAEpiC proliferation and apoptosis via the miR-194-5p/FOXP2 axis was determined using Cell counting kit-8 (CCK-8) assay, flow cytometry, and Western blotting analysis, respectively. The interactions between MALAT1, miR-194-5p, and FOXP2 were verified using dual-luciferase reporter gene assay.

Results

We identified a key lncRNA (MALAT1) and three key genes (EYA1, WNT5A, and FOXP2) that are closely correlated with the pathogenesis of ALI. LPS stimulation promoted MALAT1 expression and apoptosis and also inhibited HPAEpiC viability. MALAT1 knockdown significantly improved viability and suppressed the apoptosis of LPS-stimulated HPAEpiC. Moreover, MALAT1 directly targeted miR-194-5p, a downregulated miRNA in LPS-stimulated HPAEpiC, when FOXP2 was overexpressed. MALAT1 knockdown led to the overexpression of miR-194-5p and restrained FOXP2 expression. Furthermore, inhibition of miR-194-5p exerted a rescue effect on MALAT1 knockdown of FOXP2, whereas the overexpression of FOXP2 reversed the effect of MALAT1 knockdown on viability and apoptosis of LPS-stimulated HPAEpiC.

Conclusion

Our results demonstrated that MALAT1 knockdown alleviated HPAEpiC apoptosis by competitively binding to miR-194-5p and then elevating the inhibitory effect on its target FOXP2. These data provide a novel insight into the role of MALAT1 in the progression of ALI and potential diagnostic and therapeutic strategies for ALI patients.

lncRNA-miRNA-mRNA interaction network for colorectal cancer; An in silico analysis

BACKGROUND

Colorectal cancer (CRC) is one of the most frequent and diagnosed diseases. Accumulating evidences showed that mRNAs and noncoding RNAs play important regulatory roles in tumorigenesis. Identification and determining the relationship between them can help diagnosis and treatment of cancer.

METHODS

Here we analyzed three microarray datasets; GSE110715, GSE32323 and GSE21510, to identify differentially expressed lncRNAs and mRNAs in CRC. The adjusted p-value ≤0.05 was considered statistically significant. Gene set enrichment analysis was carried out using DAVID tool. The miRCancer database was searched to obtain differentially expressed miRNAs in colorectal cancer, and the miRDB database was used to attain the targets of the obtained miRNAs. To predict the lncRNA-miRNA interactions we used DIANA-LncBase v2 and RegRNA 2.0. Finally the lncRNA-miRNA-mRNA-signaling pathway network was constructed using Cytoscape v3.1.

RESULTS

By analyzing the three datasets, a total of 21 mRNAs (15 up- and 6 down-regulated) and 24 lncRNAs (18 up- and 6 down-regulated) were identified as common differentially expressed genes between CRC tumor and marginal tissues. Nevertheless, the constructed lncRNA-miRNA-mRNA-signaling pathway network revealed a convergence on 6 lncRNAs (3 up- and 3 downregulated), 7 mRNAs (2 up- and 5 downregulated) and 6 miRNAs (3 up- and 3 downregulated). We found that dysregulation of lncRNAs such as PCBP1-AS1, UCA1 and SNHG16 could sequester several miRNAs such as hsa-miR-582-5p and hsa-miR-198 and promote the proliferation, invasion and drug resistance of colorectal cancer cells.

CONCLUSIONS

We introduced a set of lncRNAs, mRNAs and miRNAs differentially expressed in CRC which might be considered for further experimental research as potential biomarkers of CRC development.

MicroRNA-23a acts as an oncogene in pancreatic carcinoma by targeting TFPI-2

Pancreatic carcinoma (PC) is a rapidly progressive, fatal malignant tumor with the poorest prognosis among all major carcinoma types. MicroRNAs (miRNAs/miRs) have been indicated to be key post-transcriptional regulatory factors, which are involved in cancer development. The present study was designed to investigate the effect of miR-23a on PC cell proliferation, metastasis and apoptosis. The expression of miR-23a was detected in a normal pancreatic ductal epithelial cell line and three PC cell lines, and miR-23a inhibitor or mimics were transfected into the Panc-1 and MiaPaCa2 PC cells. The association between miR-23a and tissue factor pathway inhibitor (TFPI)-2 was examined using a luciferase reporter assay. MTT and flow cytometry assays were used to assess cell viability and apoptosis, respectively. Furthermore, wound-healing, Transwell and Matrigel assays were used to evaluate cell migration and invasion abilities, and the protein expression level of TFPI-2 was determined using western blot analysis. The results of the present study revealed that miR-23a was upregulated in PC cells. Furthermore, TFPI-2 was identified as a downstream target of miR-23a, and TFPI-2 expression was found to be increased following miR-23a knockdown. In addition, functional assays revealed that downregulation of miR-23a decreased PC cell proliferation, migration and invasiveness and promoted cell apoptosis, while miR-23a overexpression exerted the opposite effects. Furthermore, TFPI-2 knockdown rescued the biological effects on PC cells, which were induced by miR-23a knockdown. The results of the present study indicated that miR-23a negatively modulated TFPI-2 expression in vitro and enhanced the malignant phenotypes of PC cells. Therefore, miR-23a may be a potential marker and/or target for the diagnosis and treatment of PC.

Diagnostic value of miR-145 and its regulatory role in macrophage immune response in tuberculosis

Tuberculosis (TB) induced by Mycobacterium tuberculosis (Mtb) is a serious global health burden. This study sought to investigate the expression and diagnostic value of serum miR-145 in TB patients and explore the biological function of miR-145 using macrophages. Serum expression levels of miR-145 were estimated by quantitative real-time PCR. A receiver operating characteristic curve was plotted to evaluate the diagnostic accuracy of miR-145. This study further focused on the effects of miR-145 on cell viability and inflammation in macrophages upon Mtb infection, and explored the potential target gene of miR-145. Serum expression levels of miR-145 were decreased in TB patients, and the upregulated inflammatory cytokines in TB patients were negatively correlated with the serum expression levels of miR-145. miR-145 had considerable diagnostic accuracy in distinguishing of TB patients from healthy individuals and differentiating between active TB cases and latent TB cases. Mtb infection induced an increase in cell viability and inflammatory responses in macrophages, but these promoting effects were rescued by the overexpression of miR-145. CXCL16 was determined as a target gene of miR-145 in macrophages. Overall, this study demonstrated that the decreased serum miR-145 expression serves a candidate diagnostic biomarker in TB patients. The overexpression of miR-145 in macrophages upon Mtb infection can suppress cell viability and infection-induced inflammation via regulating CXCL16, indicating the potential of miR-145 as a therapeutic target of TB.

LINC00261 inhibits progression of pancreatic cancer by down-regulating miR-23a-3p

Long noncoding RNAs (lncRNAs) are usually dysregulated in the progression of pancreatic cancer. This research aims to explore the function and mechanism of LINC00261 in pancreatic cancer cell viability, invasion and apoptosis. Cancer Genome Atlas (TCGA) database was applied to analyze the association between survival probability of patients and level of LINC00261 or miR-23a-3p in pancreatic cancer. Quantitative reverse transcription polymerase chain reaction was conducted to analyze the levels of LINC00261 and miR-23a-3p. Cell viability, invasion and apoptosis of pancreatic cancer cells were determined via MTT, transwell invasion assay, and flow cytometry, respectively. The target relationship between LINC00261 and miR-23a-3p was determined via dual-luciferase reporter and RNA immunoprecipitation assays. Low level of LINC00261 indicated low survival probability of pancreatic cancer patients. LINC00261 level was decreased in pancreatic cancer cells than that in normal pancreatic ductal epithelial cells. Addition of LINC00261 restrained cell viability and invasion and facilitated apoptosis. miR-23a-3p was negatively correlated with LINC00261 level and high expression of miR-23a-3p indicated low survival probability. miR-23a-3p was targeted by LINC00261 and attenuated the influence of LINC00261 on pancreatic cancer cell viability, invasion and apoptosis. In conclusion, LINC00261 overexpression repressed cell viability and invasion and enhanced apoptosis by decreasing miR-23a-3p expression in pancreatic cancer cells, indicating a new target for the treatment of pancreatic cancer.

CircFBXW7 alleviates glioma progression through regulating miR-23a-3p/PTEN axis

Increasing evidence has confirmed that circular RNAs (circRNAs) are involved in regulating the development and progression of various tumors. The aim of this study was to examine the effect of circFBXW7 on the progression of glioma and to determine its underlying mechanism. qRT-PCR was performed to measure the expression of circFBXW7, miR-23a-3p, and PTEN in tissues and cell lines of glioma. The proliferation ability of glioma cells was examined using the CCK-8 assay. Glioma cell migration and invasion capacity were detected using Transwell assays. The dual-luciferase reporter gene assay was employed to examine the correlation between miR-23a-3p and circFBXW7 or PTEN. The expression levels of the related genes were determined using western blotting analysis. A glioma xenograft tumor model was employed to evaluate the functional roles of circFBXW7 in vivo. CircFBXW7 was found to be aberrantly downregulated in glioma tumor tissues and cell lines. Overexpression of circFBXW7 was found to significantly inhibit the proliferation, migration and invasion ability of the glioma cells. Moreover, bioinformatic analysis and dual-luciferase reporter assays confirmed that circFBXW7 can directly target miR-23a-3p, which then blocks the binding of miR-23a-3p to the 3' un-translated region (UTR) of PTEN. Mechanically, circFBXW7 suppresses cell proliferation and metastasis in glioma by sponging miR-23a-3p, resulting in elevated PTEN expression. In addition, in vivo experiments also confirmed that circFBXW7 overexpression effectively halts tumor growth and metastasis. Consistent with the in vitro observations, circFBXW7 overexpression significantly decreased miR-23a-3p, Ki-67, and N-cadherin, as well as increased PTEN and E-cadherin levels. Our results revealed that circFBXW7 exhibits antiproliferative and antimetastasis activities via sponging miR-23a-3p to elevate PTEN expression in glioma, which may offer a novel target for clinical therapy and diagnosis of glioma.

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

BACKGROUND

The prognostic impact of microRNA (miRNA) expression levels in pancreatic cancer (PC) has been estimated for years, but the outcomes are controversial and heterogeneous. Therefore, we comprehensively reviewed the evidence collected on miRNA expression in PC to determine this effect.

RESULTS

PC patients with high miR-21 (HR=2.61, 95%CI=1.68-4.04), miR-451a (HR=2.23, 95%CI=1.23-4.04) or miR-1290 (HR=1.43, 95%CI=1.04-1.95) levels in blood had significantly poorer OS (P<0.05). Furthermore, PC patients with high miR-10b (HR=1.73, 95%CI=1.09-2.76), miR-17-5p (HR=1.91, 95%CI=1.30-2.80), miR-21 (HR=1.90, 95%CI=1.61-2.25), miR-23a (HR=2.18, 95%CI=1.52-3.13), miR-155 (HR=2.22, 95%CI=1.27-3.88), miR-203 (HR=1.65, 95%CI=1.14-2.40), miR-221 (HR=1.72, 95%CI=1.08-2.74), miR-222 levels (HR=1.72, 95%CI=1.02-2.91) or low miR-29c (HR=1.39, 95%CI=1.08-1.79), miR-126 (HR=1.55, 95%CI=1.23-1.95), miR-218 (HR=2.62, 95%CI=1.41-4.88) levels in tissues had significantly shorter OS (P<0.05).

CONCLUSIONS

In summary, blood miR-21, miR-451a, miR-1290 and tissue miR-10b, miR-17-5p, miR-21, miR-23a, miR-29c, miR-126, miR-155, miR-203, miR-218, miR-221, miR-222 had significant prognostic value.

METHODS

We searched PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews to recognize eligible studies, and 57 studies comprising 5445 PC patients and 15 miRNAs were included to evaluate the associations between miRNA expression levels and overall survival (OS) up to June 1, 2019. Summary hazard ratios (HR) with 95% confidence intervals (CI) were calculated to assess the effect.

Hsa_circ_0043265 Suppresses Proliferation, Metastasis, EMT and Promotes Apoptosis in Non-Small Cell Lung Cancer Through miR-25-3p/FOXP2 Pathway

Purpose

Non-small cell lung cancer (NSCLC) is the largest type of lung cancer (LC) with a higher mortality rate. Circular RNAs (circRNAs) have been shown to play an important role in cancer progression. Therefore, this study was to explore the function of hsa_circ_0043265 in NSCLC.

Methods

The expression levels of hsa_circ_0043265, microRNA-25-3p (miR-25-3p) and forkhead box P2 (FOXP2) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Ribonuclease R (RNase R) and Actinomycin D (ActD) were used to verify the authenticity and stability of hsa_circ_0043265. Cell counting kit-8 (CCK-8), flow cytometry and transwell assays were used to evaluate the abilities of proliferation, apoptosis, migration and invasion of NSCLC cells. Also, Western blot (WB) analysis was performed to assess the levels of apoptosis, epithelial–mesenchymal transition (EMT) and proliferation-related proteins and FOXP2 protein. RNA immunoprecipitation (RIP) and dual-luciferase reporter assays were used to verify the interaction between miR-25-3p and hsa_circ_0043265 or FOXP2. Besides, mice xenograft models were constructed to confirm the effect of hsa_circ_0043265 on NSCLC tumor growth in vivo.

Results

Hsa_circ_0043265 was lowly expressed in NSCLC tissues and cells, and its overexpression inhibited the proliferation, migration, invasion and EMT process, while improved the apoptosis of NSCLC cells. MiR-25-3p could be sponged by hsa_circ_0043265, and its overexpression could invert the suppression effect of overexpressed-hsa_circ_0043265 on NSCLC progression. Moreover, FOXP2 was a target of miR-25-3p, and its silencing also could reverse the inhibition effect of overexpressed-hsa_circ_0043265 on NSCLC progression. In addition, hsa_circ_0043265 overexpression reduced the tumor growth of NSCLC in vivo.

Conclusion

Hsa_circ_0043265 could sponge miR-25-3p to improve FOXP2 expression, thereby inhibiting NSCLC progression. This study showed that hsa_circ_0043265 could be a potential biomarker for early diagnosis of NSCLC.

Non-coding RNAs in Pancreatic Ductal Adenocarcinoma

Non-coding RNAs (ncRNAs) are reported to be expressed in human cancers, including pancreatic ductal adenocarcinoma (PDAC). These ncRNAs affect the growth, migration and invasion of tumor cells by regulating cell cycle and apoptosis, as well as playing important roles in epigenetic processes, transcription and post-transcriptional regulation. It is still unclear whether alterations in ncRNAs influence PDAC development and progression. Because of this, analysis based on existing data on ncRNAs, which are crucial for modulating pancreatic tumorigenesis, will be important for future research on PDAC. Here, we summarize ncRNAs with tumor-promoting functions: HOTAIR, HOTTIP, MALAT1, lncRNA H19, lncRNA PVT1, circ-RNA ciRS-7, circ-0030235, circ-RNA_100782, circ-LDLRAD3, circ-0007534, circRHOT1, circZMYM2, circ-IARS, circ-RNA PDE8A, miR-21, miR-155, miR-221/222, miR-196b, miR-10a. While others including GAS5, MEG3, and lncRNA ENST00000480739, has_circ_0001649, miR-34a, miR-100, miR-217, miR-143 inhibit the proliferation and invasion of PDAC. Hence, we summarize the functions of ncRNAs in the occurrence, development and metastasis of PDAC, with the goal to provide guidance in the clinical diagnosis and treatment of PDAC.

The MicroRNA-23b/27b/24 Cluster Facilitates Colon Cancer Cell Migration by Targeting FOXP2

Acquisition of cell migration capacity is an early and essential process in cancer development. The aim of this study was to identify microRNA gene expression networks that induced high migration capacity. Using colon cancer HCT116 cells subcloned by transwell-based migrated cell selection, microRNA array analysis was performed to examine the microRNA expression profile. Promoter activity and microRNA targets were assessed with luciferase reporters. Cell migration capacity was assessed by either the transwell or scratch assay. In isolated subpopulations with high migration capacity, the expression levels of the miR-23b/27b/24 cluster increased in accordance with the increased expression of the short C9orf3 transcript, a host gene of the miR-23b/27b/24 cluster. E2F1-binding sequences were involved in the basic transcription activity of the short C9orf3 expression, and E2F1-small-interfering (si)RNA treatment reduced the expression of both the C9orf3 and miR-23b/27b/24 clusters. Overexpression experiments showed that miR-23b and miR-27b promoted cell migration, but the opposite effect was observed with miR-24. Forkhead box P2 (FOXP2) mRNA and protein levels were reduced by both/either miR-23b and miR-27b. Furthermore, FOXP2 siRNA treatment significantly promoted cell migration. Our findings demonstrated a novel role of the miR-23b/27b/24 cluster in cell migration through targeting FOXP2, with potential implications for the development of microRNA-based therapy targeted at inhibiting cancer migration.

miR-190b promotes colorectal cancer progression through targeting forkhead box protein P2

microRNA-190b (miR-190b) is abnormally expressed in multiple types of cancer, however, its role in colorectal cancer (CRC) is largely unknown. In the present study, it was demonstrated that miR-190b expression was upregulated in CRC cell lines compared with the normal epithelial colon cell line. Knockdown of miR-190b decreased proliferation, colony formation and invasion, and increased apoptosis of CRC cells. Furthermore, forkhead box protein P2 (FOXP2) was predicted as a target of miR-190b and further validated by luciferase activity reporter assay and western blotting. Rescue experiments showed that knockdown of FOXP2 reversed the inhibitory effects of miR-190b inhibitor on the behavior of the CRC cell lines. Taken together, the present study demonstrated the oncogenic role of miR-190b in CRC through regulation of FOXP2 expression.

miR-142-5p regulates pancreatic cancer cell proliferation and apoptosis by regulation of RAP1A

Pancreatic cancer, one of the fatal and aggressive malignancies, leads the sixth cancer-associated death in China. microRNAs are believed to exert function in the diagnosis and treatment of pancreatic cancer. In the present study, we firstly found that miR-142-5p was downregulated in pancreatic cancer tumor tissues while Ras-related protein Rap-1 A (RAP1A) was upregulated compared with para-carcinoma non-tumor tissues. Then, we found that RAP1A could be a putative target gene of miR-142-5p by bioinformatics tool TargetScan. Furthermore, we conducted luciferase reporter assay, RT-qPCR, western blot and correlation analysis to demonstrate that miR-142-5p could negatively regulate RAP1A expression by binding to its 3'UTR. In addition, cell-counting kit 8 (CCK-8) and flow cytometry assays certified that miR-142-5p overexpression may inhibit pancreatic cancer cell proliferation but promote cell apoptosis; while the variation could be reversed by co-transfected with pcDNA3.1-RAP1A. Finally, miR-142-5p overexpression downregulated p-ERK1/2, phosphate p38 mitogen-activated protein kinases (p-p38); however, the variation induced by miR-142-5p mimic could be reversed by co-transfected with pcDNA3.1-RAP1A. In conclusion, our findings indicate that targeting miR-142-5p may provide a novel strategy for the treatment of pancreatic cancer.

miR-23a-3p suppresses cell proliferation in oral squamous cell carcinomas by targeting FGF2 and correlates with a better prognosis: miR-23a-3p inhibits OSCC growth by targeting FGF2

Oral squamous cell carcinomas (OSCCs) are one of the most ubiquitous malignancies the world over, and are accompanied by a high mortality. microRNAs (miRNAs) have increasingly garnered attention with regards to the roles they play in initiation and progression of various kinds of cancers, including OSCC. It has been reported, that miR-23a-3p promotes the development of tumors for prostate cancer, gastric cancer and gliomas. The functions of miR-23a-3p in OSCC however, remain unclear. In this study, fibroblast growth factor 2 (FGF2) is revealed as a direct target of miR-23a-3p, based on luciferase assays and immunoblotting. The expression of miR-23a-3p and FGF2 were found to be significantly downregulated and upregulated in OSCC tissues respectively. This indicates a reverse correlation between miR-23a-3p and FGF2 levels. Using in vitro approaches we ascertained that miR-23a-3p might contribute to the inhibition of growth and inhibition through increasing apoptosis in OSCC cells; while an inhibitor of miR-23a-3p could reverse this effect. Examination of a clinical cohort of OSCC patients suggested that reduced expression of miR-23a-3p is correlated with more advanced cancerous stage and poorer differentiation of OSCC cell. Additionally, a survival analysis and the Cox-hazard regression model showed that higher levels of miR-23a-3p can be used reliably for prognosis of OSCC patients. This study indicates that miR-23a-3p might suppress tumor proliferation, invasion and promote apoptosis of OSCC by targeting FGF2. miR-23a-3p has the potential to be used as prognostic indicator, and could be exploited as a therapeutic reagent for OSCC in the future.