Prognostic significance of miR-218 in human hepatocellular carcinoma and its role in cell growth

High Expression of miR-218-5p in the Peripheral Blood Stream and Tumor Tissues of Pediatric Patients with Sarcomas

Sarcomas are malignant tumors that may metastasize and the course of the disease is highly aggressive in children and young adults. Because of the rare incidence of sarcomas and the heterogeneity of tumors, there is a need for non-invasive diagnostic and prognostic biomarkers in sarcomas. The aim of the study was to investigate the level of miR-218-5p in peripheral blood and tumor tissue samples of Ewing's sarcoma, osteosarcoma, spindle cell sarcoma patients, and healthy controls, and assessed whether the corresponding molecule was a diagnostic and prognostic biomarker. The study was performed patients (n = 22) diagnosed and treated with Ewing's sarcoma and osteosarcoma and in a control group of 22 healthy children who were matched for age, gender, and ethnicity with the patient group. The expression level of miR-218-5p in RNA samples from peripheral blood and tissue samples were analyzed using the RT-PCR and the expression level of miR-218-5p was evaluated by comparison with the levels in patients and healthy controls. The expression level of miR-218-5p was found to be statistically higher (3.33-fold, p = 0.006) in pediatric patients with sarcomas and when the target genes of miR-218-5p were investigated using the bioinformatics tools, the miR-218-5p was found as an important miRNA in cancer. In this study, the miR-218-5p was shown for the first time to have been highly expressed in the peripheral blood and tumor tissue of sarcoma patients. The results suggest that miR-218-5p can be used as a diagnostic and prognostic biomarker in sarcomas and will be evaluated as an important therapeutic target.

The Crucial Roles of Bmi-1 in Cancer: Implications in Pathogenesis, Metastasis, Drug Resistance, and Targeted Therapies

B-cell-specific Moloney murine leukemia virus integration region 1 (Bmi-1, also known as RNF51 or PCGF4) is one of the important members of the PcG gene family, and is involved in regulating cell proliferation, differentiation and senescence, and maintaining the self-renewal of stem cells. Many studies in recent years have emphasized the role of Bmi-1 in the occurrence and development of tumors. In fact, Bmi-1 has multiple functions in cancer biology and is closely related to many classical molecules, including Akt, c-MYC, Pten, etc. This review summarizes the regulatory mechanisms of Bmi-1 in multiple pathways, and the interaction of Bmi-1 with noncoding RNAs. In particular, we focus on the pathological processes of Bmi-1 in cancer, and explore the clinical relevance of Bmi-1 in cancer biomarkers and prognosis, as well as its implications for chemoresistance and radioresistance. In conclusion, we summarize the role of Bmi-1 in tumor progression, reveal the pathophysiological process and molecular mechanism of Bmi-1 in tumors, and provide useful information for tumor diagnosis, treatment, and prognosis.

Roles of BMI1 in the Initiation, Progression, and Treatment of Hepatocellular Carcinoma

Liver cancer has high rates of morbidity and mortality, and its treatment is a global health challenge. Hepatocellular carcinoma (HCC) accounts for 90% of all primary liver cancer cases. B-lymphoma Mo-MLV insertion region 1 (BMI1) has been identified as a proto-oncogene, which contributes to the initiation and progression of many malignant tumors. BMI1 expression is upregulated in HCC, and it influences the occurrence and development of HCC by various mechanisms, such as the INK4a/ARF locus, NF-κB signaling pathway, and PTEN/PI3K/AKT signaling pathway. In addition, the expression of BMI1 is related to prognosis and recurrence of HCC. Hence, there is clear evidence that BMI1 is a novel and valid therapeutic target for HCC. Accordingly, the development of therapeutic strategies targeting BMI1 has been a focus of recent research, providing new directions for HCC treatment. This review summarizes the role of BMI1 in the occurrence and treatment of HCC, which will provide a basis for using BMI1 as a potential target for the development of therapeutic strategies for HCC.

miR-498 Targets UBE2T to Inhibit the Proliferation of Malignant Melanoma Cells

Background: Malignant melanoma is a common malignant tumor and one of the tumors with the fastest growing incidence. The effect of microRNAs on the biological processing of malignant melanoma cells also have been reported. This study explores the ability of miR-498 to regulate the progression of malignant melanoma cells. Methods: The expression of miR-498 was detected by RT-qPCR. The proliferation, invasion, and migration of malignant melanoma cells were measured by cell counting kit-8, clone formation, and transwell assays. Flow cytometry assay detected the percentage of apoptotic cells. Western blot was used to detect the expression of markers related to epithelial-mesenchymal transition. The correction of miR-498 and UBE2T was explored by dual-luciferase assay and Western blot. Results: Overexpression of miR-498 inhibited the proliferation, invasion, migration, and induced cell apoptosis of M14 and A375 cells. In addition, the expression of epithelial-mesenchymal transition-related factors was altered by the overexpression of miR-498. miR-498 can directly target UBE2T 3'-UTR and inhibit UBE2T protein expression. The overexpression of UBE2T reversed the inhibitory effects of miR-498 on the progression of malignant melanoma cells. Furthermore, UBE2T mRNA was significantly highly expressed in malignant melanoma tissues. The high expression of UBE2T was associated with the poor overall survival rate of malignant melanoma patients. Conclusions: Altogether, our findings demonstrated that miR-498 significantly inhibited the proliferation, invasion, migration, and induced apoptosis of malignant melanoma cells and confirmed that miR-498 regulated malignant melanoma cell progression by targeting UBE2T.

Targeted delivery of miR-218 via decorated hyperbranched polyamidoamine for liver cancer regression

Hepatocellular carcinoma (HCC) is one of most common causes of cancer death worldwide. MicroRNA (miRNA) replacement gene therapy is a novel approach for HCC management. MiR-218 is a promising tumor suppressor miRNA that is down-regulated in HCC. Here, our aim was the targeted delivery of miR-218 expressing DNA plasmid (pmiR-218) to suppress HCC in vitro and in vivo. Hyperbranched polyamidoamine was synthesized via simple and economically one-pot reaction followed by decoration with lactobionic acid (LA-PAMAM) to selectively deliver and restore miR-218 expression in HCC. In vitro cytotoxicity investigations revealed the high biocompatibility of LA-PAMAM. Furthermore, decoration of hyperbranched polymer with LA moieties enabled LA-PAMAM to deliver pmiR-218 more efficiently to HepG2 cells compared to both PMAMA and naked pmiR-218. Such efficient delivery of miR-218 resulted in suppression of HepG2 proliferation and down-regulation of its oncogenic HOXA1 target. In vivo, LA-PAMAM/pmiR-218 treatment of HCC induced by DEN and CCl₄ in mice leads to an obvious decrease in the number and size of HCC nodules. In addition, LA-PAMAM/pmiR-218 significantly improved the liver histological features, as well as down-regulated the HOXA1 in liver tissue. In conclusion, this study showed the potential of LA-PAMAM carrier for the targeted delivery of tumor suppressor miR-218 as a therapeutic candidate for HCC.

Effects and mechanism of microRNA‑218 against lung cancer

Lung cancer is the most prevalent and observed type of cancer in Xuanwei County, Yunnan, South China. Lung cancer in this area is called Xuanwei lung cancer. However, its pathogenesis remains largely unknown. To date, a number of studies have shown that microRNA (miR)‑218 functions as a tumor suppressor in multiple types of cancer. However, the role of miR‑218 and its regulatory gene network in Xuanwei lung cancer have yet to be investigated. The current study identified that the expression levels of miR‑218 in XWLC‑05 cells were markedly lower compared with those in immortalized lung epithelial BEAS‑2B cells. The present study also demonstrated that overexpression of miR‑218 could decrease cell proliferation, invasion, viability and migration in Xuanwei lung cancer cell line XWLC‑05 and NSCLC cell line NCI‑H157. Additionally, the results revealed that overexpression of miR‑218 could induce XWLC‑05 and NCI‑H157 cell apoptosis by arresting the cell cycle at G2/M phase. Finally, the present study demonstrated that overexpression of miR‑218 could lead to a significant increase in phosphatase and tensin homolog (<em>PTEN</em>) and YY1 transcription factor (<em>YY1</em>), and a decrease in B‑cell lymphoma 2 (<em>BCL‑2</em>) and BMI1 proto‑oncogene, polycomb ring finger (<em>BMI‑1</em>) at the mRNA and protein level in XWLC‑05 and NCI‑H157 cell lines. However, we did not observe any remarkable difference in the roles of miR‑218 and miR‑218‑mediated regulation of <em>BCL‑2</em>, <em>BMI‑1</em>, <em>PTEN</em> and <em>YY1</em> expression in the progression of Xuanwei lung cancer. In conclusion, miR‑218 could simultaneously suppress cell proliferation and tumor invasiveness and induce cell apoptosis by increasing <em>PTEN</em> and <em>YY1</em> expression, while decreasing <em>BCL‑2</em> and <em>BMI‑1</em> in Xuanwei lung cancer. The results demonstrated that miR‑218 might serve a vital role in tumorigenesis and progression of Xuanwei lung cancer and overexpression of miR‑218 may be a novel approach for the treatment of Xuanwei lung cancer.

Long non‑coding RNA CCAT1 enhances human non‑small cell lung cancer growth through downregulation of microRNA‑218

Long non-coding RNAs (lncRNAs) have critical functions in non-small cell lung cancer (NSCLC) growth. In the present study, we showed that lncRNA-CCAT1 was upregulated in NSCLC tissues. High expression of lncRNA-CCAT1 was related to tumor growth and reduced survival rate. We used short hairpin RNAs (shRNAs) to inhibit the expression of lncRNA-CCAT1 in NSCLC cells. In vitro and in vivo results demonstrated that lncRNA-CCAT1 knockdown suppressed tumor proliferation and induced apoptosis. Furthermore, microRNA-218 (miR-218) was confirmed as an effective target of lncRNA-CCAT1 in NSCLC. B lymphoma Mo-MLV insertion region 1 homolog (BMI-1), which served as a downstream target of miR-218, was also inhibited by lncRNA-CCAT1 knockdown. In conclusion, the present study indicated that upregulation of lncRNA-CCAT1 in NSCLC is associated with tumor malignant potential. lncRNA-CCAT1 enhances tumor growth in NSCLC by directly inhibiting miR-218 and indirectly increasing BMI-1 expression.

Knockdown of terminal differentiation induced ncRNA (TINCR) suppresses proliferation and invasion in hepatocellular carcinoma by targeting the miR-218-5p/DEAD-box helicase 5 (DDX5) axis

Terminal differentiation induced ncRNA (TINCR), a newly identified lncRNA, has been found to be associated with different human cancers including hepatocellular carcinoma (HCC). However, little is known regarding the pathological mechanisms of TINCR in HCC progression. In this study, we confirmed that TINCR expression was upregulated in HCC tumors and cell lines, and high TINCR expression was associated with larger tumor size, advanced tumor node metastasis stage, and poor prognosis. Functionally, knockdown of TINCR facilitated apoptosis and suppressed viability, colony formation and invasion in Huh7 and Hep3B cells. Mechanically, TINCR functioned as competing endogenous RNA (ceRNA) to regulate DEAD-box helicase 5 (DDX5) expression through sponging miR-218-5p. Moreover, the miR-218-5p expression was downregulated and DDX5 expression was upregulated in HCC tumors. The silencing of miR-218-5p or ectopic expression of DDX5 abated the tumor-suppressive effect of TINCR knockdown in vitro. Furthermore, si-TINCR-induced inactivation of AKT signaling was rescued by suppression of miR-218-5p or overexpression of DDX5. Also, the silencing of TINCR resulted in tumor growth inhibition in vivo. In summary, knockdown of TINCR suppressed HCC progression presumably by inactivation of AKT signaling through targeting the miR-218-5p/DDX5 axis, suggesting a novel TINCR/miR-218-5p/DDX5 pathway and therapy target for HCC.

miRNA-218 regulates the proliferation and apoptosis of cervical cancer cells via targeting Gli3

Cervical cancer (CC) is one of the most malignant tumors that affect women. Recent studies have reported that microRNAs (miRs) serve important roles in CC. The aim of the present study was to investigate the role of miR-218 in CC and to verify its underlying mechanism. The results of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) revealed that miR-218 was dramatically downregulated in CC tissues and cell lines. Furthermore, the expression of Gli3 and Ki67 was measured using RT-qPCR and the results revealed that levels of these proteins were negatively correlated with miR-218 in CC tissues. The protein expression levels were determined by western blotting. Then SiHa cell line was used to investigate the mechanism of CC. Following cell transfection, cell apoptosis and cycle analyses were performed using the flow cytometry. The results revealed that miR-218 overexpression significantly inhibited cell proliferation, apoptosis and cell cycle. Additionally, luciferase reporter assay revealed that Gli3 may be a novel and direct target of miR-218 in CC. Taken together, the results of the present study suggest that miR-218 overexpression or Gli3 knockdown may have potential as therapeutic strategies for the treatment of CC.

Down-regulation of miR-146b-5p by long noncoding RNA MALAT1 in hepatocellular carcinoma promotes cancer growth and metastasis

MicroRNAs play an important role in liver cancer genesis and progression. In this study, we identified down-regulation of miR-146b-5p associated with tumor growth, metastasis and poor survival in hepatocellular carcinoma (HCC) patients. miR-146b-5p could suppress proliferation, migration, and invasion and induced apoptosis in vitro and in vivo. Remarkably, TNF receptor associated factor 6 (TRAF6) was confirmed as a direct target of miR-146b-5p in HCC and miR-146b-5p exerted the tumor suppression roles through inhibiting the phosphorylation of Akt mediated by TRAF6. Furthermore, we identified long non-coding RNA MALAT1 as a molecular sponge of miR-146b-5p to down-regulate its expression in HCC. In general, our results indicate that miR-146b-5p inhibits tumor growth and metastasis of HCC by targeting TRAF6 mediated Akt phosphorylation.

Methylation-mediated repression of microRNA-129-2 suppresses cell aggressiveness by inhibiting high mobility group box 1 in human hepatocellular carcinoma

Aberrant expression of microRNAs (miRNAs) and its dysfunction have been revealed as crucial modulators of cancer initiation and progression. MiR-129-2 has been reported to play a tumor suppressive role in different human malignancies. Here, we demonstrated that miR-129-2 was significantly decreased in hepatocellular carcinoma (HCC) tissues and cell lines. Furthermore, miR-129-2 was expressed at significant lower levels in aggressive and recurrent tumor tissues. Clinical analysis indicated that miR-129-2 expression was inversely correlated with venous infiltration, high Edmondson-Steiner grading and advanced tumor-node-metastasis (TNM) stage in HCC. Notably, miR-129-2 was an independent prognostic factor for indicating overall survival (OS) and disease-free survival (DFS) of HCC patients. Ectopic expression of miR-129-2 inhibited cell migration and invasion in vitro and in vivo. Furthermore, we confirmed that high mobility group box 1 (HMGB1) was a direct target of miR-129-2, and it abrogated the function of miR-129-2 in HCC. Mechanistic investigations showed that miR-129-2 overexpression inhibited AKT phosphorylation at Ser473 and decreased the expression of matrix metalloproteinase2/9 (MMP2/9). Upregulation of p-AKT abolished the decreased cell migration and invasion induced by miR-129-2 in HCC. Whereas inhibition of Akt phosphorylation significantly decreased HMGB1-enhanced HCC cell migration and invasion. Moreover, we found that miR-129-2 was downregulated by DNA methylation, and demethylation of miR-129-2 increased miR-129-2 expression in HCC cells and resulted in significant inhibitory effects on cell migration and invasion. In conclusion, miR-129-2 may serve as a prognostic indicator for HCC patients and exerts tumor suppressive role, at least in part, by inhibiting HMGB1.

MicroRNA-1271 functions as a metastasis and epithelial-mesenchymal transition inhibitor in human HCC by targeting the PTP4A1/c-Src axis

MicroRNAs (miRNAs or miRs) have been shown to regulate hepatocellular carcinoma (HCC) metastasis. In the present study, we focused on the functions of miR-1271 in HCC metastasis. The downregulation of miR-1271 was found to be associated with to venous infiltration, an advanced TNM stage (III+IV stage) and a shorter survival time. Our in vitro and in vivo data demonstrated that miR-1271 prevented HCC cell migration and invasion, as well as the formation of lung metastatic clusters. In addition, miR-1271 was demonstrated to markedly inhibit the epithelial-mesenchymal transition (EMT) of HCC cells. Importantly, protein tyrosine phosphatase type IVA member 1 (PTP4A1) was identified as a direct downstream target of miR-1271 in HCC. Furthermore, we confirmed that the phosphorylation of c-Src at Tyr416 mediated by PTP4A1 was a potential anti-HCC mechanism of action of miR-1271. On the whole, our data indicate that miR-1271 inhibits HCC metastasis by targeting the PTP4A1/c-Src signaling pathway and may serve as a prospective cancer therapeutic target for HCC.

miR-218 inhibits acute promyelocytic leukemia cell growth by targeting BMI-1

Acute promyelocytic leukemia (APL) is a subtype of acute myelocytic leukemia. Previous studies have reported a number of functions and therapeutic roles of microRNAs (miRs) in APL, and have suggested that miR-218 acts as a tumor suppressor in a number of types of human cancer; however, its role in APL remains unclear. In the present study, the expression of miR-218 and its effects on the viability and proliferation of HL-60 cells was investigated. Reverse transcription-quantitative polymerase chain reaction analysis demonstrated that miR-218 was frequently downregulated in APL marrow tissues compared with normal marrow tissues. Overexpression of miR-218 significantly inhibited cell proliferation, arrested the cell cycle in the G₀/G₁ phase and induced apoptosis. In addition, B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) mRNA expression was negatively associated with miR-218 expression; BMI-1 mRNA and protein expression were downregulated following transfection with miR-218 mimic. These results indicate that miR-218 functions as tumor suppressor in APL, and the miR-218/BMI-1 signaling axis may be a potential novel diagnostic marker and therapeutic target for the treatment of APL.

Prognostic value of microRNAs in hepatocellular carcinoma: a meta-analysis

Background

Numerous articles reported that dysregulated expression levels of miRNAs correlated with survival time of HCC patients. However, there has not been a comprehensive meta-analysis to evaluate the accurate prognostic value of miRNAs in HCC.

Design

Meta-analysis.

Materials and Methods

Studies, published in English, estimating expression levels of miRNAs with any survival curves in HCC were identified up until 15 April, 2017 by performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two independent authors. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

Results

54 relevant articles about 16 miRNAs, with 6464 patients, were ultimately included. HCC patients with high expression of tissue miR-9 (HR = 2.35, 95% CI = 1.46–3.76), miR-21 (HR = 1.76, 95% CI = 1.29–2.41), miR-34c (HR = 1.64, 95% CI = 1.05–2.57), miR-155 (HR = 2.84, 95% CI = 1.46–5.51), miR-221 (HR = 1.76, 95% CI = 1.02–3.04) or low expression of tissue miR-22 (HR = 2.29, 95% CI = 1.63–3.21), miR-29c (HR = 1.35, 95% CI = 1.10–1.65), miR-34a (HR = 1.84, 95% CI = 1.30–2.59), miR-199a (HR = 2.78, 95% CI = 1.89–4.08), miR-200a (HR = 2.64, 95% CI = 1.86–3.77), miR-203 (HR = 2.20, 95% CI = 1.61–3.00) have significantly poor OS (P < 0.05). Likewise, HCC patients with high expression of blood miR-21 (HR = 1.73, 95% CI = 1.07–2.80), miR-192 (HR = 2.42, 95% CI = 1.15–5.10), miR-224 (HR = 1.56, 95% CI = 1.14–2.12) or low expression of blood miR-148a (HR = 2.26, 95% CI = 1.11–4.59) have significantly short OS (P < 0.05).

Conclusions

In conclusion, tissue miR-9, miR-21, miR-22, miR-29c, miR-34a, miR-34c, miR-155, miR-199a, miR-200a, miR-203, miR-221 and blood miR-21, miR-148a, miR-192, miR-224 demonstrate significantly prognostic value. Among them, tissue miR-9, miR-22, miR-155, miR-199a, miR-200a, miR-203 and blood miR-148a, miR-192 are potential prognostic candidates for predicting OS in HCC.

Lower expression of miR-218 in human breast cancer is associated with lymph node metastases, higher grades, and poorer prognosis

Breast cancer is considered as the most prevalent malignancy in women worldwide. Despite emergence of several prognosticators for better management of patients, there are still limitations for their clinical application due to the complexity of breast tumors, and therefore, new biomarkers for better prognosis of clinical outcomes would be of the great essence. MicroRNAs are highly conserved small non-coding regulatory RNAs involved in post-transcriptional regulating of gene expression during different cellular mechanisms. Accumulating studies suggest that miR-218 plays a multifunctional role in various cancer types and different stages. Here, to address prognostic significance of miR-218 in breast cancer, we investigate the expression profile of miR-218 and B-cell-specific Moloney murine leukemia virus integration site 1 ( BMI1) gene, as one of the putative targets of miR-218, in 33 paired breast tumors and their adjacent normal tissues with respect to the clinicopathological features of patients using quantitative real-time polymerase chain reaction. The correlation of both miR-218 and BMI1 gene expression with overall survival of breast cancer patients was also examined recruiting OncoLNC data portal. Finally, to better understand biological function of miR-218 in breast cancer, we performed in silico Gene Ontology and signaling pathway enrichment analysis on miR-218 targetome. According to our data, significant elevation of the expression of miR-218 and downregulation of BMI1 were observed in clinical breast cancer specimens compared with normal tissues ( p < 0.0001). The lower expression of miR-218 was associated with lymph node metastases, higher grades, and poorer prognosis (logrank p = 0.00988), whereas no significant difference in overall survival was observed between patients with higher and lower expression of BMI1 (logrank p = 0.254). These findings suggest that miR-218 expression profiling might be clinically applicable as a prognostic biomarker in breast cancer. In addition, our in silico enrichment analyses revealed that the association of miR-218 expression with breast cancer prognosis might be through its involvement in endocytosis and gap junction biological pathways.

NVM-1 predicts prognosis and contributes to growth and metastasis in hepatocellular carcinoma

Novel metastasis-promoting gene 1 (NVM-1) has a significantly elevated protein level in a variety of tumor tissues and is involved in metastasis. However, its functions in hepatocellular carcinoma (HCC) are not clear. The current study aimed to investigate the functions of NVM-1 in cell proliferation, apoptosis, and epithelial-mesenchymal transition in HCC. NVM-1 protein expression in HCC was assessed by immunohistochemical staining. In vitro, cell proliferation, apoptosis, and aggressiveness were determined by CCK-8, fluorescence-assisted cell sorting, TdT-UTP nick-end labeling, and transwell assays, respectively. For in vivo studies, NVM-1 knockdown HCC cells were transplanted into BALB/c nude mice. NVM-1 was frequently upregulated in HCC tissues and positive NVM-1 expression was linked with poor prognosis. NVM-1 depletion significantly inhibited cell proliferation, migration, and invasion abilities in vitro and in vivo. Apoptosis was induced after NVM-1 knockdown. In conclusion, positive NVM-1 expression confers poor prognosis to HCC patients and the NVM-1 protein level correlates with HCC cell proliferation, apoptosis, and EMT.

microRNAs involved in Parkinson's disease: A systematic review

The aim of the present study was to determine the expression of blood microRNAs (miRNAs) involved in PD in humans. For this purpose the following electronic databases were selected: MEDLINE by Pubmed, Scopus and Web of Science. The search strategy included the proposed descriptors in the Medical Subject Headings. There were no restrictions with respect to the language of the publication. In the study selection two independent reviewers initially evaluated studies that were identified by the search strategy according to titles and abstracts. The reviewers evaluated (also unassisted) the complete articles and selected studies according to the eligibility criteria specified above. Studies that were not in accordance with the adopted criteria were excluded according to the boundaries imposed by the search strategy. The following data were extracted from the selected studies: Publication identification, location where the study was conducted, study design, the sample size, the participants' characteristics, the miRNAs involved in PD, the miRNA detection and analysis method, and the type of miRNA dysregulation in PD. Through this systematic review of the literature published over the last 10 years, the expression of 91 different miRNAs were analyzed in the context of PD, with the expression of 39 of these miRNAs differing significantly between individuals with PD and healthy controls and/or between treated and untreated patients with PD. The miRNAs were extracted from mononuclear cells, leukocytes, plasma, serum and peripheral blood, and the majority of the studies used reverse transcription‑quantitative polymerase chain reaction (RT-qPCR), which is considered to be the gold standard for miRNA analysis.

Prognostic significance of low microRNA-218 expression in patients with different types of cancer: Evidence from published studies

BACKGROUND

Mounting evidence showed that microRNAs may be useful as prognostic biomarkers of cancer. Therefore, we summarize the predictive role of microRNA-218 (miR-218) for survival in patients with various cancers.

METHODS

We performed a systematic literature review and assessed the quality of included studies based on Meta-analysis of Observational Studies in Epidemiology group (MOOSE). Hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) were calculated to assess the correlation between miR-218 expression and prognosis of different cancers.

RESULTS

We identified 10 studies for pooled analyses. For overall survival, a lower expression levels of miR-218 significantly predicted poorer survival, with the pooled HR of 2.61 (95% CI: 2.11-3.22, P < 0.001). For disease-free survival/progressive-free survival/recurrence-free survival (DFS/PFS/RFS), a lower expression level of miR-218 significantly predicted worse DFS/PFS/RFS in various carcinomas, with the pooled HR of 2.73 (95% CI: 2.08-3.58, P < 0.001). Similarly, subgroup analysis by detection method, ethnicity and cancer subtype analysis suggested that lower expression of miR-218 correlated with.

CONCLUSION

Our data demonstrated that lower miR-218 expression is significantly associated with poorer overall survival (OS) and DFS/PFS/RFS and may be a novel prognostic biomarker in some cancer types.

MicroRNA-19b inhibits proliferation of gastric cancer cells by targeting B-cell CLL/lymphoma 3

Previous studies reported that the aberrant expression of miR-19b in gastric cancer tissues and circulating miR-19b is a potential biomarker to indicate progression of gastric cancer. However, the prognostic significance of miR-19b, and its role and underlying mechanisms in gastric cancer remain poorly investigated. In the present study, we demonstrated that the expression of miR-19b was aberrantly downregulated in both gastric cancer tissues and cell lines. Clinical association analyses disclosed that the reduced expression of miR-19b was significantly associated with adverse clinicopathological characteristics including poor differentiation, large tumor size and advanced tumor-node-metastasis (TNM) stage. Gastric cancer patients with low expression of miR-19b had prominent shorter overall survival and disease-free survival. Gain-of-function studies indicated that miR-19b overexpression inhibited cell proliferation and cell cycle progression in MGC-803 cells. While miR-19b silencing promoted cell proliferation and cell cycle progression in SGC-7901 cells. Furthermore, in vivo experiments showed that miR-19b overexpression suppressed the tumor growth of MGC-803 cells. Notably, miR-19b inversely regulated B-cell CLL/lymphoma 3 (BCL3) abundance in gastric cancer cells. BCL3 was identified as a direct target of miR-19b using luciferase reporter assays. Moreover, BCL3 knockdown abolished the effects of miR-19b knockdown on gastric cancer cells. In conclusion, our data suggest that miR-19b may potentially serve as a novel prognostic biomarker and therapeutic target for gastric cancer.

BMI1: A Biomarker of Hematologic Malignancies

BMI1 oncogene is a catalytic member of epigenetic repressor polycomb group proteins. It plays a critical role in the regulation of gene expression pattern and consequently several cellular processes during development, including cell cycle progression, senescence, aging, apoptosis, angiogenesis, and importantly self-renewal of adult stem cells of several lineages. Preponderance of evidences indicates that deregulated expression of PcG protein BMI1 is associated with several human malignancies, cancer stem cell maintenance, and propagation. Importantly, overexpression of BMI1 correlates with therapy failure in cancer patients and tumor relapse. This review discusses the diverse mode of BMI1 regulation at transcriptional, posttranscriptional, and posttranslational levels as well as at various critical signaling pathways regulated by BMI1 activity. Furthermore, this review highlights the role of BMI1 as a biomarker and therapeutic target for several subtypes of hematologic malignancies and the importance to target this biomarker for therapeutic applications.

miR-517a is an independent prognostic marker and contributes to cell migration and invasion in human colorectal cancer

Colorectal cancer (CRC) is a highly invasive tumor that is frequently associated with distant metastasis, which is the primary cause of poor prognosis. However, the mechanisms of metastasis remain poorly understood. MicroRNAs (miRNAs/miRs) have been considered to be implicated in CRC progression. In particular, miR-517a is proposed as a novel tumor-associated miRNA and has a potential role in tumor metastasis. The expression of miR-517a in CRC specimens was detected by reverse transcription-quantitative polymerase chain reaction. Transwell assays were performed to determine the migration and invasion of CRC cells. The putative target genes of miR-517a were disclosed using publicly available databases and western blot analysis. The present study identified that the expression of miR-517a was significantly higher in CRC tissues as compared with adjacent non-tumor tissues. Clinical analysis indicated that increased expression of miR-517a was correlated with poor prognostic features and poor long-term survival of CRC patients. In vitro evidences demonstrated that downregulation of miR-517a inhibited cell migration and invasion in HCT-116 cells. By contrast, upregulation of miR-517a increased the number of migrated and invaded SW480 cells. Notably, miR-517a expression was inversely regulated by forkhead box J3 (FOXJ3) abundance in CRC cells. Furthermore, an inverse correlation between miR-517a and FOXJ3 expression was observed in CRC tissues. In conclusion, miR-517a appears to be an independent prognostic marker for predicting survival of CRC patients, and may promote cell migration and invasion by inhibiting FOXJ3.

Expression of microRNA-218 and its clinicopathological and prognostic significance in human glioma cases

BACKGROUND

MicroRNAs are a class of noncoding RNAs which regulate multiple cellular processes during tumor development. The purpose of this report is to investigate the clinicopathological and prognostic significance of miR-218 in human gliomas.

MATERIALS AND METHODS

Quantitative RT-PCR (qRT-PCR) was conducted to detect the expression of miR-218 in primary normal human astrocytes, three glioma cell lines and 98 paired glioma and adjacent normal brain tissues.Associations of miR-218 with clinicopathological variables of glioma patients were statistically analyzed. Finally, a survival analysis was performed using the Kaplan-Meier method and Cox's proportional hazards model.

RESULTS

The expression level of miR-218 in primary normal human astrocytes was significantly higher than that in glioma cell lines (p<0.01). Also, the expression level of miR-218 in glioma tissues was significantly downregulated in comparison with that in the adjacent normal brain tissues (p<0.001). Statistical analyses demonstrated that low miR-218 expression was closely associated with advanced WHO grade (p=0.002) and low Karnofsky performance score (p=0.010) of glioma patients. Kaplan-Meier analysis with the log-rank test showed that patients with low-miR-218 expression had poorer disease-free survival and overall survival (p=0.0045 and 0.0124, respectively). Multivariate analysis revealed that miR-218 expression was independently associated with the disease-free survival (p=0.009) and overall survival (p=0.004) of glioma patients.

CONCLUSIONS

Our results indicate that miR-218 is downregulated in gliomas and that its status might be a potential valuable biomarker for glioma patients.

microRNA-497 inhibits cell proliferation and induces apoptosis by targeting YAP1 in human hepatocellular carcinoma

microRNAs (miRNAs) function as oncogenes or tumor suppressors in human cancers by targeting mRNAs for degradation and/or translational repression. miR‐497 has been proposed as a tumor suppressive miRNA and its deregulation is observed in human cancers. However, the prognostic value of miR‐497 and its underlying molecular pathways involved in the initiation and development of hepatocellular carcinoma (HCC) are poorly investigated. In the present study, we found that the mean level of miR‐497 in HCC tissues was lower than that in adjacent nontumor tissues. Clinical data indicated that low expression of miR‐497 was prominently associated with adverse prognostic features of HCC including high serum alpha‐fetoprotein (AFP) level, large tumor size, high Edmondson–Steiner grading and advanced tumor–node–metastasis (TNM) stage. Furthermore, miR‐497 was an independent prognostic factor for indicating both 5‐year overall survival and disease‐free survival of HCC patients. Gain‐ and loss‐of‐function studies showed that miR‐497 reduced cell proliferation and induced apoptosis in HCC cells. Yes‐associated protein 1 (YAP1) was identified as a direct target of miR‐497 in HCC. An inverse correlation between YAP1 and miR‐497 expression was observed in HCC tissues. Notably, YAP1 knockdown abrogated the effects of miR‐497 deletion on HCC cells with decreased cell proliferation and increased apoptosis. In conclusion, we report that miR‐497 is a potent prognostic indicator and may suppress tumor growth of HCC by targeting YAP1.

Up-regulation of miR-130b expression level and down-regulation of miR-218 serve as potential biomarker in the early detection of human osteosarcoma

Background

Osteosarcoma (OS) is a primary malignant bone tumor with high morbidity that principally emerges in children and adolescents. MiRNAs regulate a variety of normal physiologic processes and are involved in tumorigenesis and development of multiple malignancies, including OS. This study was aimed to evaluate the clinical significance of miR-130b and miR-218 in osteosarcoma patient.

Methods

We utilized quantitative real-time PCR to evaluate the level of miR-130b and miR-218 expressions in OS patients and normal tissues and their relationship with clinicopathological features and survival in OS patients.

Results

QRT-PCR indicated that miR-130b expression in tumor tissues was strongly elevated than adjacent non-tumor tissues (P < 0.001), while the level of miR-218 expression in osteosarcoma tissues was down-regulated than adjacent non-tumor tissues (P < 0.001). We evaluated the clinical significance of miR-130b and miR-218 in osteosarcoma. Clinical correlation analysis showed that increased expression of miR-130b and decreased expression of miR-218 were significantly associated with advanced tumor stage (x² = 6.285, P < 0.009; x² = 7.172, P < 0.007), distant metastasis (x²  = 5.528; P < 0.001; x² = 4.617, P < 0.001) and size of tumor (x² = 5.01, P = 0.013; x² = 4.271, P = 0.019).

Conclusions

Taken together, our data indicated that high miR-130b level and low level of miR-218 are associated with poor clinicopathological characteristics. Furthermore, miR-130b may play a key role in the progression of osteosarcoma.

MiR-218-targeting-Bmi-1 mediates the suppressive effect of 1,6,7-trihydroxyxanthone on liver cancer cells

Traditional Chinese medicine is recently emerged as anti-cancer therapy or adjuvant with reduced side-effects and improved quality of life. In the present study, an active ingredient, 1,6,7-trihydroxyxanthone (THA), derived from Goodyera oblongifolia was found to strongly suppress cell growth and induce apoptosis in liver cancer cells. MicroRNAs are a group of small non-coding RNAs that regulate gene expression at post-transcriptional levels. Our results demonstrated that miR-218 was up-regulated and oncogene Bmi-1 was down-regulated by THA treatment. Further investigation showed that THA-induced-miR-218 up-regulation could lead to activation of tumor suppressor P16(Ink4a) and P14(ARF), the main down-stream targets of Bmi-1. In conclusion, THA might be a potential anti-cancer drug candidate, at least in part, through the activation of miR-218 and suppression of Bmi-1 expression.

ATPase inhibitory factor 1 is a potential prognostic marker for the migration and invasion of glioma

Adenosine triphosphatase inhibitory factor 1 (IF1) has previously been considered to be a driving oncogene in human cancers. Several studies have revealed that IF1 overexpression is present in a variety of tumor types and promotes tumor growth and metastasis. The present study aimed to investigate the clinical significance of IF1 in glioma and the role of IF1 in cell migration and invasion. The mRNA and protein expression of IF1 in glioma tissues was found to be significantly increased compared with the expression in normal brain tissues (P<0.05). The presence of IF1 expression was significantly associated with an advanced clinical stage in glioma (P<0.05). Furthermore, the presence of IF1 expression was found to be associated with a reduced overall survival rate of glioma patients (P<0.05). Multivariate Cox regression analysis indicated that IF1 was an independent factor for predicting the overall survival rate of patients with glioma (P<0.05). IF1 knockdown also significantly reduced the number of migratory and invasive U251 and U87 cells (P<0.05). In addition, IF1 knockdown inhibited the expression of nuclear factor-κB (NF-κB) and Snai1, and led to increased E-cadherin expression and reduced vimentin expression. In conclusion, the presence of IF1 expression is associated with poor clinicopathological features in glioma. IF1 expression is an independent prognostic marker for predicting the overall survival rate of patients with glioma. Mechanistically, IF1 may promote glioma cell migration and invasion through the NF-κB/Snai1 axis.

MicroRNA-153 acts as a prognostic marker in gastric cancer and its role in cell migration and invasion

MicroRNA (miRNA)-153 (miR-153) has been considered as a novel tumor-related miRNA and is found to be significantly deregulated in human cancers. In this study, we found that the expression levels of miR-153 were obviously lower in gastric cancer tissues than those in matched adjacent nontumor tissues. Otherwise, miR-153 was expressed at significantly lower levels in aggressive tumor tissues. Clinical association analysis indicated that low expression of miR-153 was prominently correlated with poor prognostic features in gastric cancer. Furthermore, we demonstrated that the low expression of miR-153 was correlated with short 5-year survival of gastric cancer patients. Multivariate Cox regression analysis indicated that miR-153 was an independent prognostic marker in gastric cancer. Our in vitro studies showed that upregulation of miR-153 reduced cell migration and invasion in MKN-45 cells. Meanwhile, downregulation of miR-153 promoted SGC-7901 cell migration and invasion. An inverse correlation between miR-153 and SNAI1 expression was observed in gastric cancer tissues. In addition, upregulation of miR-153 reduced SNAI1 expression and subsequently suppressed epithelial–mesenchymal transition (EMT) with elevated expression of E-cadherin and reduced expression of vimentin in MKN-45 cells. Furthermore, downregulation of miR-153 increased SNAI1 expression and promoted EMT in SGC-7901 cells. In conclusion, miR-153 is an independent prognostic marker for predicting survival of gastric cancer patients and may promote gastric cancer cell migration and invasion, by inhibiting SNAI1-induced EMT.

miR-218 expression in osteosarcoma tissues and its effect on cell growth in osteosarcoma cells

OBJECTIVE

To investigate the expression of miR-218 and its clinical significance in osteosarcoma tissues and explore its effect on proliferation and apoptosis in osteosarcoma cells.

METHODS

miR-218 expression was detected in 76 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR). MiR-218 was over-expressed by exogenous miR-218 plasmids in Saos-2 cells, and then BrdU cell proliferation assay and flow cytometry were used to determine cell proliferation and apoptosis.

RESULTS

The expression of miR-218 in osteosarcoma tissues was significantly lower than those in normal tumor-adjacent tissues (t=8.735, P<0.001). MiR-218 expression in tumor tissues was significantly correlated with tumor size (χ(2)=5.380, P=0.020), clinical stage (χ(2)=6.692, P=0.010) and distant metastasis (χ(2)=4.180, P=0.041). MiR-218 was obviously over-expressed by exogenous miR-218 plasmids (t=19.42, P<0.001), and miR-218 overexpression significantly reduced cell proliferation (t=9.045, P<0.001) and induced apoptosis (t=12.38, P<0.001) in Saos-2 cells.

CONCLUSIONS

The low-expression of miR-218 is correlated with the poor clinicopathological features in osteosarcoma. Moreover, miR-218 overexpression reduces cancer cell proliferation and induces apoptosis in Saos-2 cells, suggesting that miR-218 may play a key role in the progression of human osteosarcoma.

TPX2 is a prognostic marker and contributes to growth and metastasis of human hepatocellular carcinoma

Targeting protein for Xenopus kinesin-like protein 2 (TPX2), a microtubule-associated protein, impacts spindle assembly in human cells. Several studies have demonstrated that TPX2 is overexpressed in different types of human cancers and promotes tumor growth and metastasis. In this study, we found that the expression level of TPX2 was obviously higher in hepatocellular carcinoma (HCC) tissues than in matched nontumor tissues. Elevated expressions of TPX2 mRNA were observed in all HCC cell lines (HepG2, Hep3B, SMMC-7721, Bel-7402 and Huh7) as compared with that in a non-transformed hepatic cell line (LO2). Clinical analysis indicated that the positive expression of TPX2 was significantly correlated with venous infiltration, high Edmondson-Steiner grading and advanced TNM tumor stage in HCC. Furthermore, TPX2 was a novel prognostic marker for predicting 5-year overall survival (OS) and disease-free survival (DFS) of HCC patients. In vitro studies found that TPX2 knockdown significantly inhibited cell proliferation and viability in both Hep3B and HepG2 cells. Moreover, TPX2 knockdown obviously slowed down tumor growth in a nude mouse xenograft model. Otherwise, TPX2 knockdown prominently suppressed HCC cell invasion and migration. In conclusion, these results indicate that TPX2 may serve as a prognostic marker and promotes tumorigenesis and metastasis of HCC.