MicroRNA-20a-5p targets RUNX3 to regulate proliferation and migration of human hepatocellular cancer cells

Circulating miR-20a-5p as a biomarker associated with cabergoline responsiveness in patients with hyperprolactinemia and pituitary adenomas

OBJECTIVE

Dopamine agonist (DA) treatment is effective for hyperprolactinemia and reduces tumor size in patients with prolactinoma; however, prolonged DA administration without prolactinoma causes fibrosis around tumor tissues. Therefore, we aimed to identify circulating microRNAs (miRNAs) as potential biomarkers to predict prolactinoma in patients with hyperprolactinemia and pituitary tumors.

DESIGN

Plasma samples were collected from 3 comparison groups: (1) patients clinically diagnosed with prolactinoma vs nonfunctioning pituitary adenoma (NFPA) based on response to cabergoline treatment, (2) patients with surgically confirmed prolactinoma vs NFPA, and (3) patients before and after cabergoline treatment. Candidate miRNAs from the initial nCounter assay were validated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in a larger cohort of 247 patients with hyperprolactinemia and 37 controls.

METHODS

The nCounter assay was used for miRNA expression profiling, and the qRT-PCR validated the candidate miRNAs in the plasma and tumor tissue samples. Total RNA sequencing was conducted on pituitary tumor tissues to identify transcriptomic alterations. Furthermore, candidate miRNA target genes and their biological roles were analyzed using prolactinoma cell lines.

RESULTS

Three miRNA candidates (miR-20a-5p, miR-424-5p, and miR-514a-5p) were selected by analyzing 3 sets of expression comparisons between the 2 groups. Furthermore, the relative miR-20a-5p expression significantly increased in prolactinoma compared with that in normal pituitary glands, NFPA, growth hormone-secreting pituitary adenoma, and adrenocorticotropic hormone-secreting pituitary adenoma. In MMQ and GH4 cells, miR-20a-5p inhibition decreased prolactinoma cell proliferation and prolactin secretion.

CONCLUSIONS

Circulating miR-20a-5p is a potential biomarker for prolactinoma, which could be associated with responsiveness to DAs.

Comprehensive analysis of miRNA-mRNA regulatory pairs associated with colorectal cancer and the role in tumor immunity

BACKGROUND

MicroRNA (miRNA) which can act as post-transcriptional regulators of mRNAs via base-pairing with complementary sequences within mRNAs is involved in processes of the complex interaction between immune system and tumors. In this research, we elucidated the profiles of miRNAs and target mRNAs expression and their associations with the phenotypic hallmarks of colorectal cancers (CRC) by integrating transcriptomic, immunophenotype, methylation, mutation and survival data.

RESULTS

We conducted the analysis of differential miRNA/mRNA expression profile by GEO, TCGA and GTEx databases and the correlation between miRNA and targeted mRNA by miRTarBase and TarBase. Then we detected using qRT-PCR and validated the diagnostic value of miRNA-mRNA regulator pairs by the ROC, calibration curve and DCA. Phenotypic hallmarks of regulatory pairs including tumor-infiltrating lymphocytes, tumor microenvironment, tumor mutation burden, global methylation and gene mutation were also described. The expression levels of miRNAs and target mRNAs were detected in 80 paired colon tissue samples. Ultimately, we picked up two pivotal regulatory pairs (miR-139-5p/ STC1 and miR-20a-5p/ FGL2) and verified the diagnostic value of the complex model which is the combination of 4 signatures above-mentioned in 3 testing GEO datasets and an external validation cohort.

CONCLUSIONS

We found that 2 miRNAs by targeting 2 metastasis-related mRNAs were correlated with tumor-infiltrating macrophages, HRAS, and BRAF gene mutation status. Our results established the diagnostic model containing 2 miRNAs and their respective targeted mRNAs to distinguish CRCs and normal controls and displayed their complex roles in CRC pathogenesis especially tumor immunity.

Unraveling Therapeutic Opportunities and the Diagnostic Potential of microRNAs for Human Lung Cancer

Lung cancer is a major public health problem and a leading cause of cancer-related deaths worldwide. Despite advances in treatment options, the five-year survival rate for lung cancer patients remains low, emphasizing the urgent need for innovative diagnostic and therapeutic strategies. MicroRNAs (miRNAs) have emerged as potential biomarkers and therapeutic targets for lung cancer due to their crucial roles in regulating cell proliferation, differentiation, and apoptosis. For example, miR-34a and miR-150, once delivered to lung cancer via liposomes or nanoparticles, can inhibit tumor growth by downregulating critical cancer promoting genes. Conversely, miR-21 and miR-155, frequently overexpressed in lung cancer, are associated with increased cell proliferation, invasion, and chemotherapy resistance. In this review, we summarize the current knowledge of the roles of miRNAs in lung carcinogenesis, especially those induced by exposure to environmental pollutants, namely, arsenic and benzopyrene, which account for up to 1/10 of lung cancer cases. We then discuss the recent advances in miRNA-based cancer therapeutics and diagnostics. Such information will provide new insights into lung cancer pathogenesis and innovative diagnostic and therapeutic modalities based on miRNAs.

MicroRNA-17 Family Targets RUNX3 to Increase Proliferation and Migration of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one common cancer in the world. Previous studies have shown that miR-17 family members are elevated in most tumors and promote tumor progression. However, there is no comprehensive analysis of the expression and functional mechanism of the microRNA-17 (miR-17) family in HCC. The aim of this study is to comprehensively analyze the function of the miR-17 family in HCC and the molecular mechanism of its role. Bioinfoimatics analysis of the miR-17 family expression profile and its relationship to clinical significance using The Cancer Genome Atlas (TCGA) database, and this result was confirmed using quantitative real-time polymerase chain reaction. miR-17 family members were tested for functional effects through transfection of miRNA precursors and inhibitors, and monitoring cell viability and migration by cell count and wound healing assays. In addition, we using dual-luciferase assay and Western blot demonstrated the targeting relationship between the miRNA-17 family and RUNX3. These members of miR-17 family were highly expressed in HCC tissues, and the overexpression of the miR-17 family promoted the proliferation and migration of SMMC-7721 cells, whereas treatment with anti-miR17 inhibitors caused the opposite effects. Notably, we also found that inhibitors anti-each member of miR-17 can suppress the expression of the entire family member. In addition, they can bind to the 3' untranslated region of RUNX3 to regulate its expression at the translational level. Our results proved that miR-17 family has oncogenic characteristics, overexpression every member of the family contributed to HCC cell proliferation and migration by reducing the translation of RUNX3.

Circular RNAs: pivotal role in the leukemogenesis and novel indicators for the diagnosis and prognosis of acute myeloid leukemia

Acute myeloid leukemia (AML) is an aggressive hematological malignancy and affected patients have poor overall survival (OS) rates. Circular RNAs (circRNAs) are a novel class of non-coding RNAs (ncRNAs) with a unique loop structure. In recent years, with the development of high-throughput RNA sequencing, many circRNAs have been identified exhibiting either up-regulation or down-regulation in AML patients compared with healthy controls. Recent studies have reported that circRNAs regulate leukemia cell proliferation, stemness, and apoptosis, both positively and negatively. Additionally, circRNAs could be promising biomarkers and therapeutic targets in AML. In this study, we present a comprehensive review of the regulatory roles and potentials of a number of dysregulated circRNAs in AML.

MicroRNA-20a-5p regulates the epithelial-mesenchymal transition of human hepatocellular carcinoma by targeting RUNX3

BACKGROUND

MicroRNA-20a (miR-20a) is dysregulated in many types of malignancies, including human hepatocellular carcinoma (HCC), but its expression level and functional significance in HCC are still disputed. We aimed to study the role of miR-20a-5p in HCC and its downstream molecular mechanisms.

METHODS

We used real-time polymerase chain reaction to detect the expression of miR-20a-5p and runt-related transcription factor 3 ( RUNX3 ) in HCC and paraneoplastic tissue, transfected Huh7 and highly metastatic human hepatocellular carcinoma (MHCC97H) cells. A live cell workstation was used to observe the proliferation and migration of transfected cells. The invasiveness of transfected cells was verified by Transwell assay. Cell apoptosis was detected by flow cytometry. The expression levels of proteins after transfection were measured using simple western immunoblot measurements. Gene expression profiles between HCC and normal samples were obtained from The Cancer Genome Atlas. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment results were processed by the database for annotation, visualization and integrated discovery. Potential target genes of miR-20a-5p were predicted to further investigate how miR-20a-5p regulates epithelial-mesenchymal transition (EMT) in HCC.

RESULTS

MiR-20a-5p was significantly highly expressed in HCC tissues, and overexpression of miR-20a-5p significantly promoted HCC cell proliferation, migration, and invasion and inhibited apoptosis in vitro. The protein expression of E-cadherin was decreased and that of vimentin was increased after overexpression of miR-20a-5p in HCC cells. We discovered the intersection of genes from miRDB, miR TarBase, and TargetScan, obtained 397 target genes and finally focused on RUNX3. RUNX3 was not only reduced in HCC specimens but also drastically reduced in HCC cells overexpressing miR-20a-5p. RUNX3 expression decreased with elevated miR-20a-5p, which activated downstream EMT signaling and promoted cell proliferation, migration, and invasion.

CONCLUSIONS

Since RUNX3 is involved in EMT in HCC, as proven by previous research, our findings provide further evidence for a novel regulatory pathway comprising the miR-20a/RUNX3/EMT axis that upregulates EMT signaling and enhances the migration of HCC cells.

Identification of exosomal hsa-miR-483-5p as a potential biomarker for hepatocellular carcinoma via microRNA expression profiling of tumor-derived exosomes

To date, most studies of exosomes related to hepatocellular carcinoma (HCC) have used commercial cancer cell lines or patient plasma as source material. In this study, we isolated exosomes directly from HCC tissues to investigate the potential of exosomal contents as biomarkers for HCC. Exosomes were identified and verified using transmission electron microscopy, nano-flow cytometry analysis, and western blotting. Tissue-derived exosomal miRNA expression was profiled by high-throughput sequencing, and differential expression of miRNAs was validated by quantitative real-time polymerase chain reaction analysis. The diagnostic performance of differentially expressed exosomal miRNAs for HCC was evaluated by receiver operating characteristic curve analysis. Target genes of these miRNAs were verified using luciferase reporter assays, and their functions were studied through in vitro and rescue assays. In total, 225 differentially expressed exosomal miRNAs were identified in HCC samples compared with adjacent liver tissues, and some were associated with HCC tumorigenesis and progression. Comparison of the expression profiles of tissue-derived and plasma-derived exosomal miRNAs identified hsa-miR-483-5p as the only differentially expressed miRNA detected in both HCC tissue and plasma, and this was in a validation group of HCC patients. Analysis of the diagnostic performance of plasma exosomal hsa-miR-483-5p or plasma hsa-miR-483-5p found that both could differentiate HCC and non-HCC cases. In vitro ectopic miR-483-5p expression promoted HCC cell proliferation. CDK15 was confirmed to bind with miR-483-5p directly, and thus, miR-483-5p may function by downregulating CDK15. Hsa-miR-483-5p represents a potential specific and sensitive biomarker for HCC diagnosis.

Regulatory mechanism of miR-20a-5p expression in Cancer

MicroRNAs(miRNAs) are non-coding single-stranded RNA molecules encoded by endogenous genes with a length of about 22 nucleotides. The dysregulation of miRNAs has been proven to be one of the vital causes of cancer, which makes them a biomarker for cancer diagnosis and prognosis. Compared with surgery and chemotherapy, nucleic acid therapy targeting specific miRNAs is a promising candidate for cancer treatment. miR-20a-5p plays an anticancer role in high-incidence human cancers such as cervical cancer, breast cancer and leukemia, which is of great importance in the diagnosis of cancers. The up-regulation and down-regulation of miR-20a-5p offers a possible breakthrough for the treatment of cancers. In this paper, we aim to investigate the functional significance of miR-20a-5p in different cancers, reviewing the expression differences of miR-20a-5p in cancer, while systematically summarizing the changes of circRNA-miR-20a-5p networks, and probe how it promotes messenger RNA (mRNA) degradation or inhibits mRNA translation to regulate downstream gene expression. We've also summarized the biogenesis mechanism of miRNAs, and emphasized its role in cell proliferation, cell apoptosis and cell migration. On this basis, we believe that miR-20a-5p is a promising and effective marker for cancer diagnosis, prognosis and treatment.

MicroRNAs and Heat Shock Proteins in Breast Cancer Biology

Breast cancer has five major immune types; luminal A, luminal B, HER2, Basal-like, and normal-like. Cells produce a family of protein called heat shock proteins (Hsps) in response to exposure to thermal and other proteotoxic stresses play essential roles in cancer metabolism and this large family shows a diverse set of Hsp involvement in different breast cancer immune types. Recently, Hsp members categorized according to their immune type roles. Hsp family consists of several subtypes formed by molecular weight; Hsp70, Hsp90, Hsp100, Hsp40, Hsp60, and small molecule Hsps. Cancer cells employ Hsps as survival factors since most of these proteins prevent apoptosis. Several studies monitored Hsp roles in breast cancer cells and reported Hsp27 involvement in drug resistance, Hsp70 in tumor cell transformation-progression, and interaction with p53. Furthermore, the association of Hsp90 with steroid receptors and signaling proteins in patients with breast cancer directed research to focus on Hsp-based treatments. miRNAs are known to play key roles in all types of cancer that are upregulated or downregulated in cancer which respectively referred to as oncogenes (oncomirs) or tumor suppressors. Expression profiles of miRNAs may be used to classify, diagnose, and predict different cancer types. It is clear that miRNAs play regulatory roles in gene expression and this work reveals miRNA correlation to Hsp depending on specific breast cancer immune types. Deregulation of specific Hsp genes in breast cancer subtypes allows for identification of new targets for drug design and cancer treatment. Here, we performed miRNA network analysis by recruiting Hsp genes detected in breast cancer subtypes and reviewed some of the miRNAs related to aforementioned Hsp genes.

microRNA-20b-5p overexpression combing Pembrolizumab potentiates cancer cells to radiation therapy via repressing programmed death-ligand 1

Radiation therapy (RT) is widely applied in cancer treatment. The sensitivity of tumor cells to RT is the key to the treatment. This study probes the role and mechanism of miR-20b-5p in Pembrolizumab’s affecting the radiosensitivity of tumor cells. After Pembrolizumab treatment or cell transfection (miR-20b-5p mimics and miR-20b-5p inhibitors), tumor cells (NCI-H460 and ZR-75-30) were exposed to RT. The sensitivity of NCI-H460 and ZR-75-30 to RT was evaluated by monitoring cell proliferation and apoptosis. The dual-luciferase reporter assay and RNA immunoprecipitation (RIP) were adopted to evaluate the binding relationship between miR-20b-5p and CD274 (PD-L1). The xenograft model was established in nude mice to examine the mechanism of action of Pembrolizumab in vivo. Our outcomes exhibited that either Pembrolizumab treatment or miR-20b-5p overexpression potentiated radiosensitivity of tumor cells. Overexpressing miR-20b-5p enhanced radiosensitization of Pembrolizumab in vivo and in vitro by targeting PD-L1 and inactivating PD-L1/PD1. Overall, miR-20b-5p overexpression combined with Pembrolizumab potentiated cancer cells’ sensitivity to RT by repressing PD-L1/PD1.Abbreviations Akt: serine/threonine kinase 1; cDNA: complementary DNA; CO₂: carbon dioxide; EDTA: Ethylene Diamine Tetraacetic Acid; ENCORI: The Encyclopedia of RNA Interactomes; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; IGF2BP2: insulin like growth factor 2 mRNA binding protein 2; IHC: Immunohistochemistry; LncRNA MALAT1: Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1; miRNAs: MicroRNAs; Mt: Mutant type; MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide; NC: negative control; NR2F2: nuclear receptor subfamily 2 group F member 2; NSCLC: non-small cell lung cancer; OD: optical density; PBS: phosphate-buffered saline; PD-L1: Programmed death-ligand 1; PD-1: programmed death 1; PI3K: phosphatidylinositol 3-kinase; qRT-PCR: Quantitative reverse transcription-polymerase chain reaction; RIP: RNA immunoprecipitation; RIPA: Radio Immunoprecipitation Assay; RRM2: ribonucleotide reductase regulatory subunit M2; RT: Radiation therapy; U6: U6 small nuclear RNA; V: volume; WB: Western blot; Wt: wild type; x ± sd: mean ± standard deviation.

MiR-20a-5p functions as a potent tumor suppressor by targeting PPP6C in acute myeloid leukemia

Acute myeloid leukemia (AML) is as a highly aggressive and heterogeneous hematological malignancy. MiR-20a-5p has been reported to function as an oncogene or tumor suppressor in several tumors, but the clinical significance and regulatory mechanisms of miR-20a-5p in AML cells have not been fully understood. In this study, we found miR-20a-5p was significantly decreased in bone marrow from AML patients, compared with that in healthy controls. Moreover, decreased miR-20a-5p expression was correlated with risk status and poor survival prognosis in AML patients. Overexpression of miR-20a-5p suppressed cell proliferation, induced cell cycle G0/G1 phase arrest and apoptosis in two AML cell lines (THP-1 and U937) using CCK-8 assay and flow cytometry analysis. Moreover, miR-20a-5p overexpression attenuated tumor growth in vivo by performing tumor xenograft experiments. Luciferase reporter assay and western blot demonstrated that protein phosphatase 6 catalytic subunit (PPP6C) as a target gene of miR-20a-5p was negatively regulated by miR-20a-5p in AML cells. Furthermore, PPP6C knockdown imitated, while overexpression reversed the effects of miR-20a-5p overexpression on AML cell proliferation, cell cycle G1/S transition and apoptosis. Taken together, our findings demonstrate that miR-20a-5p/PPP6C represent a new therapeutic target for AML and a potential diagnostic marker for AML therapy.

Potential Networks Regulated by MSCs in Acute-On-Chronic Liver Failure: Exosomal miRNAs and Intracellular Target Genes

Acute-on-chronic liver failure (ACLF) is a severe syndrome associated with high mortality. Alterations in the liver microenvironment are one of the vital causes of immune damage and liver dysfunction. Human bone marrow mesenchymal stem cells (hBMSCs) have been reported to alleviate liver injury via exosome-mediated signaling; of note, miRNAs are one of the most important cargoes in exosomes. Importantly, the miRNAs within exosomes in the hepatic microenvironment may mediate the mesenchymal stem cell (MSC)-derived regulation of liver function. This study investigated the hepatocyte exosomal miRNAs which are regulated by MSCs and the target genes which have potential in the treatment of liver failure. Briefly, ACLF was induced in mice using carbon tetrachloride and primary hepatocytes were isolated and co-cultured (or not) with MSCs under serum-free conditions. Exosomes were then collected, and the expression of exosomal miRNAs was assessed using next-generation sequencing; a comparison was performed between liver cells from healthy versus ACLF animals. Additionally, to identify the intracellular targets of exosomal miRNAs in humans, we focused on previously published data, i.e., microarray data and mass spectrometry data in liver samples from ACLF patients. The biological functions and signaling pathways associated with differentially expressed genes were predicted using gene ontology and Kyoto Encyclopedia of Genes and Genomics enrichment analyses; hub genes were also screened based on pathway analysis and the prediction of protein-protein interaction networks. Finally, we constructed the hub gene-miRNA network and performed correlation analysis and qPCR validation. Importantly, our data revealed that MSCs could regulate the miRNA content within exosomes in the hepatic microenvironment. MiR-20a-5p was down-regulated in ACLF hepatocytes and their exosomes, while the levels of chemokine C-X-C Motif Chemokine Ligand 8 (CXCL8; interleukin 8) were increased in hepatocytes. Importantly, co-culture with hBMSCs resulted in up-regulated expression of miR-20a-5p in exosomes and hepatocytes, and down-regulated expression of CXCL8 in hepatocytes. Altogether, our data suggest that the exosomal miR-20a-5p/intracellular CXCL8 axis may play an important role in the reduction of liver inflammation in ACLF in the context of MSC-based therapies and highlights CXCL8 as a potential target for alleviating liver injury.

Serum miRNAs associated with tumor-promoting cytokines in non-small cell lung cancer

Tumor-promoting cytokines are a cause of tumor progression; therefore, identifying key regulatory microRNAs (miRNAs) for controlling their production is important. The aim of this study is to identify promising miRNAs associated with tumor-promoting cytokines in non-small cell lung cancer (NSCLC). We identified circulating miRNAs from 16 published miRNA profiles. The selected miRNAs were validated in the serum of 32 NSCLC patients and compared with 33 patients with other lung diseases and 23 healthy persons using quantitative real-time PCR. The cytokine concentration was investigated using the enzyme-linked immunoassay in the same sample set, with clinical validation of the miRNAs. The correlation between miRNA expression and cytokine concentration was evaluated by Spearman’s rank correlation. For consistent direction, one up-regulated miRNA (miR-145) was found in four studies, and seven miRNAs were reported in three studies. One miRNA (miR-20a) and four miRNAs (miR-25-3p, miR-223, let-7f, and miR-20b) were reported in six and five studies. However, their expression was inconsistent. In the clinical validation, serum miR-145 was significantly down-regulated, whereas serum miR-20a was significantly up-regulated in NSCLC, compared with controls. Regarding serum cytokine, all cytokines [vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and transforming growth factor β (TGF-β)], except tumor necrosis factor-α (TNF-α), had a higher level in NSCLC patients than controls. In addition, we found a moderate correlation between the TGF-β concentration and miR-20a (r = −0.537, p = 0.002) and miR-223 (r = 0.428, p = 0.015) and a weak correlation between the VEGF concentration with miR-20a (r = 0.376, p = 0.037) and miR-223 (r = −0.355, p = 0.046). MiR-145 and miR-20a are potential biomarkers for NSCLC. In addition, the regulation of tumor-promoting cytokine, through miR-20a and miR-223, might be a new therapeutic approach for lung cancer.

Circulating MicroRNA-19b Identified From Osteoporotic Vertebral Compression Fracture Patients Increases Bone Formation

Circulating microRNAs (miRNAs) play important roles in regulating gene expression and have been reported to be involved in various metabolic diseases, including osteoporosis. Although the transcriptional regulation of osteoblast differentiation has been well characterized, the role of circulating miRNAs in this process is poorly understood. Here we discovered that the level of circulating miR-19b was significantly lower in osteoporotic patients with vertebral compression fractures than that of healthy controls. The expression level of miR-19b was increased during osteoblastic differentiation of human mesenchymal stem cells (hMSCs) and MC3T3-E1 cells, and transfection with synthetic miR-19b could promote osteoblastic differentiation of hMSCs and MC3T3-E1 cells. PTEN (phosphatase and tensin homolog deleted from chromosome 10) was found to be directly repressed by miR-19b, with a concomitant increase in Runx2 expression and increased phosphorylation of AKT (protein kinase B, PKB). The expression level of circulating miR-19b in aged ovariectomized mice was significantly lower than in young mice. Moreover, the osteoporotic bone phenotype in aged ovariectomized mice was alleviated by the injection of chemically modified miR-19b (agomiR-19b). Taken together, our results show that circulating miR-19b plays an important role in enhancing osteoblastogenesis, possibly through regulation of the PTEN/pAKT/Runx2 pathway, and may be a useful therapeutic target in bone loss disorders, such as osteoporosis. © 2019 American Society for Bone and Mineral Research.

Function and mechanisms of microRNA-20a in colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of cancer-associated mortality worldwide. CRC currently has no specific biomarkers to promote its diagnosis and treatment and the underlying mechanisms regulating its pathogenesis have not yet been determined. MicroRNAs (miRs) are small, non-coding RNAs that exhibit regulatory functions and have been demonstrated to serve a crucial role in the post-transcriptional regulatory processes of gene expression that is associated with cell physiology and disease progression. Recently, abnormal miR-20a expression has been identified in a number of cancers types and this has become a novel focus within cancer research. High levels of miR-20a expression have been identified in CRC tissues, serum and plasma. In a recent study, miR-20a was indicated to be present in feces and to exhibit a high sensitivity to CRC. Therefore, miR-20a may be used as a marker for CRC and an indicator that can prevent the invasive examination of patients with this disease. Changes in the expression of miR-20a during chemotherapy can be used as a biomarker for monitoring resistance to treatment. In conclusion, miR-20a exhibits the potential for clinical application as a novel diagnostic biomarker and therapeutic target for use in patients with CRC. The present study focused on the role and mechanisms of miR-20a in CRC.

Ethanol promotes alcohol-related colorectal cancer metastasis via the TGF-β/RUNX3/Snail axis by inducing TGF-β1 upregulation and RUNX3 cytoplasmic mislocalization

BACKGROUND

Alcohol intake is a well-known lifestyle risk factor for CRC, and an increasing number of studies have revealed that alcohol intake is also tightly associated with CRC metastasis. However, the effect of alcohol on CRC metastasis and its underlying mechanism remain unclear.

METHODS

A retrospective cohort study was performed to investigate the characteristics of patients with alcohol-related CRC. The effects of ethanol on the biological behaviours of CRC cells were assessed through in vivo and in vitro assays using the Lieber-DeCarli ethanol liquid diet and ethanol, respectively. The ethanol-mediated signalling pathway and downstream factors were screened through ELISA, western blot, immunofluorescence and co-immunoprecipitation.

FINDINGS

Most patients with alcohol-related CRC, particularly those with tumour metastasis, were characterized by a notably higher circulating ethanol level and a lower systemic acetaldehyde level. Moreover, CRC cells accumulated in ethanol, but not acetaldehyde, to notably higher levels compared with adjacent normal cells. Alcohol intake significantly promoted CRC metastasis via the ethanol-mediated TGF-β/Smad/Snail axis, and ethanol induced the cytoplasmic mislocalization of RUNX3 and further promoted the aggressiveness of CRC by targeting Snail. Pirfenidone (PFD) significantly eliminated the effects of ethanol on CRC metastasis by specifically blocking TGF-β signalling.

INTERPRETATION

Alcohol intake plays a vital role in CRC metastasis via the ethanol-mediated TGF-β/RUNX3/Snail axis, and PFD might be a novel therapeutic management strategy for CRC.

MicroRNA‑301a‑3p overexpression promotes cell invasion and proliferation by targeting runt‑related transcription factor 3 in prostate cancer

MicroRNAs (miRNAs) are known to serve a role in tumorigenic programs. The dysregulated expression of miR‑301a‑3p may affect the progression of various types of human cancer; however, the expression and the role of miR‑301a‑3p in prostate cancer are still unclear. The present study aimed to clarify the role and molecular mechanism of miR‑301a‑3p in prostate cancer. The results demonstrated that the expression of miR‑301a‑3p was significantly upregulated in human prostate cancer tissues and in several prostate cancer cell lines. In vitro overexpression of miR‑301a‑3p notably increased prostate cancer cell proliferation and invasion. Bioinformatics analysis revealed that runt‑related transcription factor 3 (RUNX3) may be a target of miR‑301a‑3p, which was confirmed by Dual‑luciferase reporter assay. Western blot analysis also demonstrated that miR‑301a‑3p regulated the protein expression levels of RUNX3. In addition, the results indicated that miR‑301a‑3p may regulate the Wnt signaling pathway, and rescue experiments indicated that RUNX3 contributed to the effects of miR‑301a‑3p on cell proliferation and invasion through Wnt signaling. In conclusion, these findings suggested that miR‑301a‑3p may promote prostate cancer cell invasion and proliferation by targeting RUNX3, and provided insight into understanding prostate cancer pathogenesis. miR‑301a‑3p may be a potential therapeutic candidate to treat prostate cancer.

Downregulation of miR-552 in hepatocellular carcinoma inhibits cell migration and invasion, and promotes cell apoptosis via RUNX3

Research conducted previously has indicated that microRNAs (miRs) have potential effects on the pathogenesis of hepatocellular carcinoma (HCC). The biological functions of miR-552 have been well documented in colon cancer; however, the role of miR-552 in HCC remains unclear. The present study evaluated the effects of miR-552 in HCC physiology, using HCC cell lines as model. An miR-552 inhibitor was transfected into HCC cell lines to knock down the expression of miR-552. Reverse transcription-quantitative PCR and western blot analysis were used to detect the expression of miR-552 and Runt-related transcription factor 3 (RUNX3), respectively. MTT assay was used to analyze cell viability, whilst Transwell and wound-healing assay were used to investigate cell migration. Flow cytometry was performed to measure cell apoptosis. The direct association between RUNX3 and miR-552 was evaluated using dual luciferase reporter assay. The expression of miR-552 was significantly elevated in HCC tumor tissues compared with the adjacent healthy samples. Additionally, transfection with the miR-552 inhibitor decreased cell viability and migration. miR-552 knockdown also increased HCC cell apoptosis in vitro. In conclusion, these results suggest that miR-552 has an oncogenic function in HCC and is a potential biomarker for detecting HCC.

Expression Profile of microRNAs in Hypertrophic Cardiomyopathy and Effects of microRNA-20 in Inducing Cardiomyocyte Hypertrophy Through Regulating Gene MFN2

Myocardial hypertrophy is an important cause of heart failure and sudden death. Studies have shown that Mitofusin-2 (MFN2) is downregulated in myocardial hypertrophy, but the upstream regulation mechanism underlying its downexpression in cardiomyocytes is still unclear. This study aims to identify the expression profile of microRNAs (miRNAs) in hypertrophic cardiomyopathy (HCM) and explore the function of miRNA-20 in inducing cardiomyocyte hypertrophy through regulating MFN2. Through miRNA + mRNA microarray analysis, 1451 miRNAs were identified, 367 miRNAs expressed differently between groups. Meanwhile, a number of 24,718 mRNAs were identified, among which 5850 mRNAs were upregulated and 3005 mRNAs were downregulated in HCM group compared with the control group. Expression of hsa-miRNA-20a-5p was 2.26 times higher in the HCM group compared with the control group and 7 target gene prediction programs predicted MFN2 as a target of miRNA-20. In vitro model of hypertrophic cardiomyocytes displayed high expression level of miRNA-20, atrial natriuretic peptide (ANP) mRNA, and protein, accompanying low expression level of Mfn2 mRNA and protein, which meant miRNA-20 played a role in cardiomyocyte hypertrophy and might interact with MFN2 to function. Thereafter, overexpression of miRNA-20 led to cell hypertrophy accompanied with lowly expressed Mfn2 mRNA and protein. When transfected with miRNA-20 inhibitors, the expression of miRNA-20 and ANP gene was attenuated and MFN2 was the other way around. The cell surface area of Ang II group and mimic group was significantly larger compared with the control group, and in the inhibitor+Ang II group, the area was significantly decreased compared with the Ang II group. Dual-luciferase assays showed that miRNA-20 bound to 3' untranslated region of MFN2 and inhibited its expression. In conclusion, hypertrophic myocardium and normal myocardium have different miRNA expression profiles and the effect of miRNA-20 reducing the expression of MFN2 plays a role in promoting cardiomyocyte hypertrophy.

MiR-20a, a novel promising biomarker to predict prognosis in human cancer: a meta-analysis

Background

Recently, microRNA-20a (miR-20a) has been reported to influence the clinical features and may have prognostic value in human cancers. The present meta-analysis assessed the prognostic role of miR-20a in various carcinomas.

Methods

Literature searches of seven electronic databases were performed for eligible articles of the prognostic role of miR-20a in human cancers. Hazard ratios (HR) for overall survival (OS), disease free survival (DFS), progression-free survival (PFS) as well as their 95% confidence intervals (95%CIs) were used to assess the influence of miR-20a expression on patient prognosis. Odds ratio (OR) and 95%CIs were applied to evaluate the correlation between miR-20a expression and clinicopathological characteristics.

Results

Based on the OS analyzed by log rank tests, there was a significant association between miR-20a levels and OS by fixed effects model. By subgroup analyses, the significance was also observed in the studies of specimen derived from blood and gastrointestinal cancer group. The independent prognostic role of miR-20a expression for the OS was observed significantly by fixed effects model. In addition, we observed significant association between miR-20a expression levels and DFS of log rank tests, DFS of cox regression. Significant relation of gender/differentiation and the expression level of miR-20a was identified.

Conclusions

Base on the findings, the elevated miR-20a expression level is related to poor prognosis of gastrointestinal cancer patients. As for other types of carcinomas, the results are still not stable and more studies are required to further identify miR-20a prognostic values. In addition, miR-20a expression level is relatively higher in women than that in men, and increased miR-20a expression level is linked to poor tumor differentiation.

MicroRNA-20a Regulates Glioma Cell Proliferation, Invasion, and Apoptosis by Targeting CUGBP Elav-Like Family Member 2

OBJECTIVE

MicroRNAs (miRNAs) are a class of small noncoding RNAs that play important roles in tumor development and progression. miR-20a acts as an oncogene in many cancers; however, the underlying role of miR-20a in human glioma remains unknown.

METHODS

Glioma tissue samples were obtained from 32 patients with primary glioma who had undergone surgery at the First Affiliated Hospital of Sun Yat-sen University (Guangzhou, China). Twenty-two normal brain tissue samples used as controls were obtained by internal decompression in patients who had undergone surgery for cerebral injury and cerebral hemorrhage at the same hospital.

RESULTS

Quantitative reverse transcription polymerase chain reaction showed upregulation of miR-20a in glioma tissues and cell lines compared with normal brain tissue and normal human astrocytes. Functional assays showed that miR-20a promotes proliferation and invasion and inhibits apoptosis in glioma cells. The bioinformatic analysis showed that CELF2 (CUGBP Elav-like family member 2) is a direct target gene of miR-20a, which was confirmed using a luciferase reporter assay. Downregulation of CELF2 reversed the effects of inhibiting miR-20a expression.

CONCLUSIONS

Collectively, these results suggest a critical role for miR-20a in glioma cell apoptosis, proliferation, and invasion via the direct targeting of CELF2 and indicate its potential application in cancer therapy.

HOTAIR induces the ubiquitination of Runx3 by interacting with Mex3b and enhances the invasion of gastric cancer cells

BACKGROUND

Long non-coding RNAs (LncRNAs) exert their functions mainly by binding to their corresponding proteins. Runt-related transcription factor 3 (Runx3) is an important transcription factor that functions as a tumor suppressor in gastric cancer. Whether there is an interplay between LncRNAs and Runx3 remains unclear.

METHODS

RPISeq was applied to screen the LncRNAs that potentially bind to Runx3. The interaction between LncRNA HOX antisense intergenic RNA (HOTAIR) and Runx3 was validated by RNA Immunoprecipitation and RNA pull-down assays. The role of Mex3b in the ubiquitination of Runx3 induced by HOTAIR was assessed by immunoprecipitation. Pearson's correlation between HOTAIR mRNA expression and Runx3 protein expression was analyzed. Cell migration and invasion were explored by transwell assays.

RESULTS

We found that HOTAIR was bound to Runx3 protein and identified the fragment of HOTAIR spanning 1951-2100 bp as the specific binding site. In addition, mex-3 RNA binding family member B (Mex3b) was an E3 ligase involved in HOTAIR-induced ubiquitous degradation of Runx3. Silencing the expression of HOTAIR or Mex3b attenuated the degradation of Runx3. In human gastric cancer tissues, HOTAIR was negatively associated with the expression level of Runx3 protein (Pearson coefficient - 0.501, p = 0.025). Inhibition of HOTAIR significantly suppressed gastric cancer cell migration and invasion through upregulating claudin1, which could be reversed by co-deficiency of Runx3.

CONCLUSIONS

These results uncovered the novel interaction between HOTAIR and Runx3, and provided potential therapeutic targets on the metastasis of gastric cancer.

Interplay of miRNAs and Canonical Wnt Signaling Pathway in Hepatocellular Carcinoma

Hepatocellular carcinoma is one of the leading causes of cancer death worldwide and the activation of canonical Wnt signaling pathway is universal in hepatocellular carcinoma patients. MicroRNAs are found to participate in the pathogenesis of hepatocellular carcinoma by activating or inhibiting components in the canonical Wnt signaling pathway. Meanwhile, transcriptional activation of microRNAs by canonical Wnt signaling pathway also contributes to the occurrence and progression of hepatocellular carcinoma. Pharmacological inhibition of hepatocellular carcinoma pathogenesis and other cancers by microRNAs are now in clinical trials despite the challenges of identifying efficient microRNAs candidates and safe delivery vehicles. The focus of this review is on the interplay mechanisms between microRNAs and canonical Wnt signaling pathway in hepatocellular carcinoma, and a deep understanding of the crosstalk will promote to develop a better management of this disease.

Clinical evaluation of circulating miR-548a-3p and -20a expression in malignant pleural mesothelioma patients

AIM

miRNAs may act as promising diagnostic and prognostic biomarkers of mesothelioma. This study integrates serum  miR-548a-3p and miR-20a expression based on in silico data analysis followed by clinical validation in malignant mesothelioma patients (malignant pleural mesothelioma [MPM]).

PATIENTS & METHODS

Serum miR-548a-3p and  miR-20a level was assessed in the serum of patients with MPM, chronic asbestos exposure and healthy volunteers by quantitative real-time PCR.

RESULTS

The expression of serum miR-548a-3p and  miR-20a was positive in 91.6 and 96.7% MPM patients, respectively. Both miRNAs were able to segregate between cases and controls. The sensitivity of the combined chosen serum miRNAs reached 100% in the diagnosis of MPM.

CONCLUSION

The current work revealed that sera miR-548a-3p and miR-20a may serve as promising novel diagnostic tools for MPM.

miRNA-20a upregulates TAK1 and increases proliferation in osteosarcoma cells

AIM

The aim of this study is to explore the function of miR-20a in osteosarcoma.

MATERIALS & METHODS

miR-20a expression was measured by real-time PCR. miR-20a mimics, inhibitor and scramble siRNA were transfected into osteosarcoma cells to observe effects on colony formation and tumor growth. Moreover, relationships of miR-20a with TAK1 were investigated by western blot and luciferase activity.

RESULTS

We found that miR-20a was downregulated in osteosarcoma, and overexpression of miR-20a reduced colony formation and tumor growth. Furthermore, the data revealed that the function of miR-20a was probably exerted via targeting the TAK1 expression. Overexpression of miR-20a sensitizes the osteosarcoma cells to chemotherapeutic drugs.

CONCLUSION

Our data identify the role of miR-20a in osteosarcoma growth, indicating its potential application in chemotherapy.

Prognostic value of high-expression of miR-17-92 cluster in various tumors: evidence from a meta-analysis

The prognostic value of miR-17-92 cluster high-expression in various tumors remains controversial. Therefore, we conducted this meta-analysis by searching literatures in PubMed, Embase, Cochrane Library, China Biology Medicine disc, China National Knowledge Infrastructure to identify eligible studies. Eventually, we analyzed 36 articles that examined 17 tumor types from 4965 patients. Consequently, high-expression of miR-17-92 cluster in various tumors was associated with unfavorable overall survival in both univariate (HR = 2.05, 95%CI: 1.58-2.65, P<0.001) and multivariate (HR = 2.14, 95%CI: 1.75-2.61, P<0.001) analyses. Likewise, similar results were found in different subgroups of country, test method, miR-17-92 cluster component, sample source and size. Additionally, high-expression of miR-17-92 cluster was linked with poor disease-free survival (Univariate: HR = 1.96, 95%CI: 1.55-2.48, P<0.001; Multivariate: HR = 2.18, 95%CI: 1.63-2.91, P<0.001), favorable progression-free survival (Univariate: HR = 0.36, 95%CI: 0.16-0.80, P = 0.012; Multivariate: HR = 1.55, 95%CI: 0.79-3.05, P = 0.201) and poor cancer specific survival in univariate rather than multivariate analyses (Univariate: HR = 1.77, 95%CI: 1.21-2.60, P = 0.004; Multivariate: HR = 1.77, 95%CI: 0.80-3.92, P = 0.160). However, no association of miR-17-92 cluster high-expression was detected with recurrence or relapse-free survival. In summary, this meta-analysis towards high-expression of miR-17-92 cluster has indicated poor prognosis of various cancers. Notably, future studies comprising large cohort size from multicenter are required to confirm our conclusions.

Effects of RUNX3 mediated Notch signaling pathway on biological characteristics of colorectal cancer cells

This study investigated the effects of runt-related transcription factor 3 (RUNX3) mediated Notch pathway on the biological behavior of colorectal cancer (CRC) SW260 cells. CRC tissues and para-carcinoma tissues were collected from 182 CRC patients who had undergone surgical treatment between January 2008 and December 2010. Immunohistochemical staining with streptavidin-peroxidase (SP) was used to detect RUNX3, Notch1 and Jagged 1 expression levels. CRC SW260 cells were divided into the following groups: Control group, si-NC group, si-RUNX3 group, DAPT group, si-RUNX3+DAPT group, and si-NC+DAPT group. Expression levels of RUNX3, and Notch signaling related genes were measured by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and western blotting in vitro. Besides, MTT, soft agar colony formation, Annexin V-FITC/PI double staining and Transwell were performed to analyze the effects of RUNX3 on cell growth and metastasis. Lower positive expression rate of RUNX3 and higher positive expression rate of Notch1 and Jagged 1 were observed in CRC tissues than those in normal adjacent tissues with a negative correlation, and the expression levels were associated with the differentiation degree, TNM staging, lymph node metastasis and tumor invasion depth (all P<0.05). RUNX3 expression was reduced in si-RUNX3 and si-RUNX3+DAPT group but the expression levels of Notch signaling related genes were markedly increased in si-RUNX3 group or decreased in DAPT and si-NC+DAPT group, as compared with those in the control group (all P<0.05). In addition, the proliferation, colony formation, migration and invasion abilities of SW260 cells were enhanced in si-RUNX3 group but were restricted in DAPT and si-NC+DAPT group, which was contrary to cell apoptosis (all P<0.05). RUNX3 contributes to attenuate the proliferation and metastasis of CRC cells, and promotes cell apoptosis through inhibition of Notch signaling pathway.

PARP inhibitor increases chemosensitivity by upregulating miR-664b-5p in BRCA1-mutated triple-negative breast cancer

Emerging evidence has shown that adding poly(ADP-ribose) polymerase (PARP) inhibitors to chemotherapy regimens is superior to the control regimens alone in BRCA1-mutated triple-negative breast cancer (TNBC) patients, but their underlying mechanisms have not been fully elucidated. In this study, using miRNA microarray analysis of two BRCA1-mutated TNBC cell lines, we found that miR-664b-5p expression was increased after adding a PARP inhibitor, olaparib, to a carboplatin (CBP) plus gemcitabine (GEM) therapy regimen. Functional assays showed miR-664b-5p overexpression inhibited proliferation, migration and invasion in BRCA1-mutated TNBC cells. CCNE2 was identified as a novel functional target of miR-664b-5p, and CCNE2 knockdown revealed effects similar to those observed with miR-664b-5p overexpression. Both CCNE2 knockdown and miR-664b-5p overexpression significantly increased the chemosensitivity of BRCA1-mutated TNBC cells. In addition, in vivo studies indicated that miR-664b-5p inhibited tumour growth compared with the control in tumour xenograft models, and we also found that CCNE2 expression was inversely correlated with miR-664b-5p expression in 90 TNBC patient samples. In conclusion, miR-664b-5p functions as a tumour suppressor and has an important role in the regulation of PARP inhibitors to increase chemosensitivity by targeting CCNE2. This may be one of the possible mechanisms by which PARP inhibitors increase chemosensitivity in BRCA1-mutated TNBC.