Increased Serum Level of MicroRNA-663 Is Correlated with Poor Prognosis of Patients with Nasopharyngeal Carcinoma

miRNA-633 and KAI1 as Potential Biomarkers of Malignant Melanoma with Gastric Cancer

OBJECTIVE

Malignant melanoma with gastric cancer is one of the most malignant tumors. However, there have been no reports on the effects of KAI1 and miRNA-633 on the survival and prognosis of patients with malignant melanoma with gastric cancer.

METHODS

Fifty patients with malignant melanoma and gastric cancer were collected from October 2017 to December 2019. The clinical parameters included clinical information, such as sex, age, tumor size, and tumor staging. RT-qPCR was used to detect the expression of KAI1 and miRNA- 633. The role of KAI1 and miRNA-633 on the overall survival of melanoma was explored by the Pearson chi-square test, Spearman-rho correlation test, Univariate and multivariate cox regression analyses, and Kaplan-Meier method. Furthermore, the bioinformatic analysis was used to verify the role of KAI1 and miRNA-633 on malignant melanoma with gastric cancer.

RESULTS

The expression of KAI1 and miRNA-633 was significantly related with the tumor size and staging of tumor (p<0.05) based on the Pearson chi-square test. Spearman's correlation coefficient displayed that KAI1 was significantly correlated with the miRNA-633 (ρ=-0.439, p=0.001). The result of multivariate cox proportional regression analysis showed that KAI1 (HR =0.109, 95% CI: 0.031-0.375, p< 0.001), and miRNA-633 (HR = 13.315, 95% CI: 3.844-46.119, p<0.001) were significantly associated with overall survival.

CONCLUSION

The low expression level of KAI1 and high expression of miRNA-633 are significantly correlated with the poor overall survival prognosis of malignant melanoma with gastric cancer, to provide a basis for KAI1 and miRNA-633 to become novel molecular targets for malignant melanoma with gastric cancer.

Small biomarkers with massive impacts: PI3K/AKT/mTOR signalling and microRNA crosstalk regulate nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumours of the head and neck in Southeast Asia and southern China. The Phosphatidylinositol 3-kinase/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signalling pathway is involved in processes related to tumour initiation/progression, such as proliferation, apoptosis, metastasis, and drug resistance, and is closely related to the clinicopathological features of NPC. In addition, key genes involved in the PI3K/AKT/mTOR signalling pathway undergo many changes in NPC. More interestingly, a growing body of evidence suggests an interaction between this signalling pathway and microRNAs (miRNAs), a class of small noncoding RNAs. Therefore, in this review, we discuss the interactions between key components of the PI3K/AKT/mTOR signalling pathway and various miRNAs and their importance in NPC pathology and explore potential diagnostic biomarkers and therapeutic targets.

Low Expression of miR-663a Indicates Poor Prognosis and Promotes Cell Proliferation, Migration, and Invasion in Breast Cancer

INTRODUCTION

Breast cancer is one of the most common malignant cancers among women worldwide. MicroRNA-663a (miR-663a) acts as a tumor suppressor gene involved in the development of various cancers.

OBJECTIVE

The aim of this study was to reveal the clinical significance and biological function of miR-663a in breast cancer.

METHODS

The expression of miR-663a in breast cancer tissues and cells was evaluated by reverse transcription-quantitative polymerase chain reaction. Kaplan-Meier survival and Cox regression analysis were performed to evaluate the prognostic significance of miR-663a in breast cancer. CCK-8 and Transwell assays were used to demonstrate the effect of miR-663a on breast cancer cell function.

RESULTS

We confirmed that the expression of miR-663a was significantly downregulated in breast cancer tissue samples and cell lines. Low miR-663a expression was significantly associated with lymph node metastasis, TNM stage, subtypes, and poor survival in breast cancer patients, indicating that miR-663a is an independent prognostic factor for patients with breast cancer. Cell function experiments revealed that low miR-663a expression promoted cell proliferation, migration, and invasion in breast cancer.

CONCLUSIONS

All experimental results demonstrated that miR-663a acts as a tumor suppressor that inhibits the proliferation, migration, and invasion of breast cancer cells, and miR-663a may be a prognostic biomarker and therapeutic target for breast cancer.

Blood levels of microRNAs associated with ischemic heart disease differ between Austrians and Japanese: a pilot study

Mortality from ischemic heart disease (IHD) is significantly lower in Japan than in Western countries. The purpose of this study was to investigate differences in circulating microRNA (miRNA) levels related to IHD in Austrians and Japanese. Participants were middle-aged healthy male Austrians (n = 20) and Japanese (n = 20). Total miRNAs in serum from each participant were analyzed using the 3D-Gene miRNA Oligo chip. Twenty-one miRNAs, previously reported as associated with IHD, were compared between Austrians and Japanese. The expression levels of miR-106a-5p, miR-135a-3p, miR-150-3p, miR-16-5p, miR-17-5p. miR-191-5p, miR-320b, miR-451a, miR-486-5p, miR-663b, and miR-92a-3p were significantly higher, while the miR-2861 expression level was significantly lower in Austrians as compared to Japanese. Both in Austrians and Japanese, there were significant positive correlations between serum expression levels of each pair of the above miRNAs except for miR-2861. The expression level of miR-2861 showed significant positive correlations with the expression levels of miR-106a-5p, miR-150-3p, miR-17-5p, miR-486-5p, miR-663b and miR-92a-3p in Austrians but not in Japanese. In pathway analysis, proinflammatory cytokine production in foam cells and collagen synthesis in vascular smooth muscle cells were associated with differentially expressed miRNAs. Difference in miRNA levels may contribute to lower cardiovascular risk in Japan than in Western countries.

MicroRNAs: Biogenesis, Functions and Potential Biomarkers for Early Screening, Prognosis and Therapeutic Molecular Monitoring of Nasopharyngeal Carcinoma

According to reports published, the aberrant expression of microRNAs (miRNAs), a class of 19–25 nucleotide-long small non-coding RNAs, is responsible for human cancers, including nasopharyngeal cancer (NPC). The dysregulation of miRNAs that act either as a tumor suppressor or oncogene, leading to a wide range of NPC pathogenesis pathways, includes the proliferation, invasion, migration as well as the metastasis of NPC cells. This article reviews and highlights recent advances in the studies of miRNAs in NPC, with a specific demonstration of the functions of miRNA, especially circulating miRNAs, in the pathway of NPC pathogenesis. Additionally, the possible use of miRNAs as early screening and prognostic biomarkers and for therapeutic molecular monitoring has been extensively studied.

Downregulation of miRNA-663b protects against hypoxia-induced injury in cardiomyocytes by targeting BCL2L1

In the present study, the role of microRNA-663b (miR-663b) in cardiomyocyte injury was examined. Reverse transcription-quantitative PCR (RT-qPCR) was performed to detect miR-663b expression in hypoxia-induced H9c2 cells. The results revealed that miR-663b expression was significantly upregulated in hypoxia-induced H9c2 cells compared with control cells. TargetScan analysis and dual-luciferase reporter assays demonstrated that miR-663b directly targeted the B-cell lymphoma 2 like 1 (BCL2L1) gene. RT-qPCR and western blotting data indicated that BCL2L1 expression was significantly downregulated in hypoxia-induced H9c2 cells compared with control cells. Under hypoxic conditions, H9c2 cells were transfected with miR-663b inhibitor, inhibitor control, miR-663b inhibitor + control small interfering (si)RNA or miR-663b inhibitor + BCL2L1-siRNA for 48 h. ELISA against creatine kinase-muscle/brain (CK-MB) and cardiac troponin 1 (cTnI) demonstrated that the miR-663b inhibitor reduced CK-MD and cTnI release and increased mitochondrial viability when compared with hypoxia-treated cells. Additionally, the miR-663b inhibitor significantly increased H9c2 cell viability and decreased cell apoptosis under hypoxic conditions. The results of ELISA further revealed that the miR-663b inhibitor decreased the release of various inflammatory factors, including tumour necrosis factor α, interleukin (IL) 1β and IL-6 in H9c2 cells under hypoxic conditions. These changes were reversed following BCL2L1 knockdown. In conclusion, miR-663b inhibition protected cardiomyocytes against hypoxia-induced injury by targeting BCL2L1 and may potentially be a novel target for the treatment of patients with myocardial infarction.

MicroRNAs as Therapeutic Targets in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a malignancy of epithelial origin that is prone to local invasion and early distant metastasis. Although concurrent chemotherapy and radiotherapy improves the 5-year survival outcomes, persistent or recurrent disease still occurs. Therefore, novel therapeutic targets are needed for NPC patients. MicroRNAs (miRNAs) play important roles in normal cell homeostasis, and dysregulations of miRNA expression have been implicated in human cancers. In NPC, studies have revealed that miRNAs are dysregulated and involved in tumorigenesis, metastasis, invasion, resistance to chemo- and radiotherapy, and other disease- and treatment-related processes. The advantage of miRNA-based treatment approaches is that miRNAs can concurrently target multiple effectors of pathways involved in tumor cell differentiation and proliferation. Thus, miRNA-based cancer treatments, alone or combined with standard chemotherapy and/or radiotherapy, hold promise to improve treatment response and cure rates. In this review, we will summarize the dysregulation of miRNAs in NPC initiation, progression, and treatment as well as NPC-related signaling pathways, and we will discuss the potential applications of miRNAs as biomarkers and therapeutic targets in NPC patients. We conclude that miRNAs might be potential promising therapeutic targets in nasopharyngeal carcinoma.

Circulating microRNAs in head and neck cancer: a scoping review of methods

Circulating microRNAs have been described as head and neck cancer biomarkers in multiple anatomical subsites including the oral cavity, nasopharynx, larynx, salivary glands and the skin. While there is an expanding volume of published literature showing the significance of individual or panels of microRNAs, the clinical validation of candidate biomarkers is lacking. The various methods used to collect, store, process and interpret these microRNAs are likely introducing bias and contributing to the inconsistent results. A systematic scoping review was conducted using PRISMA standards to identify published English literature between 2007 and 2018. Pubmed and EMBASE databases were searched using specific keyword combinations related to head and neck cancer, circulating samples (whole blood, plasma or serum) and microRNA. Following the title and abstract review, two primary authors appraised the articles for their suitability to include in the review based on the detail of methodological descriptions. Thirty suitable articles were identified relating to nasopharyngeal carcinoma, oral cavity, oropharyngeal and laryngeal squamous cell carcinoma as well as primary salivary gland malignancies. Comprehensive methodological analysis identified poor reporting of detailed methodology, variations in collection, storage, pre-processing, RNA isolation and relative quantification including normalisation method. We recommend standardising the pre-processing, RNA isolation, normalisation and relative quantitation steps at biomarker discovery phase. Such standardisation would allow for bias minimisation and effective progression into clinical validation phases.

Systematic review and meta-analysis of prognostic microRNA biomarkers for survival outcome in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal cancer (NPC), despite being one of the most malignant head and neck carcinomas (HNC), lacks comprehensive prognostic biomarkers that predict patient survival. Therefore, this systematic review and meta-analysis is aimed to evaluate the potential prognostic value of miRNAs as prognostic biomarkers in NPC.

METHODS

PRISMA guidelines were used to conduct this systematic review and meta-analysis study. Permutations of multiple "search key-words" were used for the search strategy, which was limited to articles published between January 2012 and March 2018. The retrieved articles were meticulously searched with multi-level screening by two reviewers and confirmed by other reviewers. Meta-analysis was performed using Hazard Ratios (HR) and associated 95% Confidence Interval (CI) of survival obtained from previously published studies. Publication bias was assessed by Egger's bias indicator test and funnel plot symmetry.

RESULTS

A total of 5069 patients across 21 studies were considered eligible for inclusion in the systematic review, with 65 miRNAs being evaluated in the subsequent meta-analysis. Most articles included in this study originated from China and one study from North Africa. The forest plot was generated using cumulated survival data, resulting in a pooled HR value of 1.196 (95% CI: 0.893-1.601) indicating that the upregulated miRNAs increased the likelihood of death of NPC patients by 19%.

CONCLUSION

To our knowledge, this is the first meta-analysis that examines the prognostic effectiveness of miRNAs as biomarkers in NPC patients. We noted that the combined effect estimate of HR across multiple studies indicated that increased miRNA expression in NPC potentially leads to poor overall survival. However, further large-scale prospective studies on the clinical significance of the miRNAs, with sizable cohorts are necessary in order to obtain conclusive results.

Gemcitabine enhances OSI-027 cytotoxicity by upregulation of miR-663a in pancreatic ductal adenocarcinoma cells

Pancreatic ductal adenocarcinoma (PDAC) is well-known to be the most deadly malignancy with the worst survival rate of all cancers. Gemcitabine-based chemotherapy is the most common treatment option for pancreatic ductal adenocarcinoma. However, it offers little therapeutic value in many cases due to the rapid development of chemoresistance. MicroRNAs (miRNAs) have been found to play pivotal roles in the chemotherapeutic resistance of PDAC. In the present study, we examined the molecular basis for the effective combination of OSI-027 and gemcitabine (GEM). Firstly, we identified a specific miRNA expression profile in PDAC cells after treatment with either of these drugs. We found that miR-663a was significantly upregulated after treatment with GEM and downregulated after OSI-027 treatment. With combination of the two drugs, miR-663a level was lower than the GEM group, but higher than the OSI-027 group. Real-time quantitative PCR confirmed these observations. To further establish the role of miR-663a in OSI-027 and GEM resistance in pancreatic cancer, we transfected PDAC cells with miR-663a mimic or miR-663a inhibitor. Cell viability and proliferation assays showed that miR-663a mimic enhanced drug sensitivity, while inhibitor promoted drug resistance. Moreover, we found that the combined effect of OSI-027 and GEM disappeared after inhibiting miR-663a. Our study clearly demonstrates that GEM upregulates miR-663a, thereby promoting the sensitivity of pancreatic cancer cells to OSI-027. Our study suggests that miR-663a expression may be a useful indicator of the potential for chemoresistance and provides a potential new therapeutic target to avert chemoresistance in PDAC.

miR-663a inhibits tumor growth and invasion by regulating TGF-β1 in hepatocellular carcinoma

Background

The dysregulation of miR-663a is frequently observed in many human cancers. However, the functional role and precise mechanism of miR-663a have been controversial in hepatocellular carcinoma (HCC) and need to be studied in depth.

Methods

The expression of miR-663a was detected in human cell lines and HCC tissues by quantitative RT-PCR (qRT-PCR), and data from the Cancer Genome Atlas (TCGA). Cell proliferation was investigated using MTS, EdU, colony formation assays, and xenograft animal experiments, and the cell invasion capacity was evaluated using the transwell assay. The target gene of miR-663a was identified by qRT-PCR, Western blot, and dual-luciferase reporter assays. The clinicopathological features of miR-663a and the correlation between miR-663a and TGF-β1 expression were also investigated in the clinical samples of HCC.

Results

miR-663a was significantly downregulated in HCC cells relative to immortal normal liver cells, as indicated using qRT-PCR, and the lower expression of miR-663a was also confirmed in HCC tissue samples and the data from TCGA. The expression of miR-663a in HCC tissue samples was statistically significantly associated with size and the number of tumors. In addition, the upregulation of miR-663a inhibited the proliferation and invasion of HCC cells in vitro. Further study showed that miR-663a directly targeted transforming growth factor beta 1 (TGF-β1) to suppress HCC invasion, and that the inhibitory effect of miR-663a on cell invasion could be regulated by TGF-β1. In vivo studies showed that miR-663a significantly inhibited tumor growth. A negative correlation between miR-663a and TGF-β1 expression was also confirmed from the clinical samples of HCC.

Conclusions

miR-663a acts as a tumor suppressor and exerts a substantial role in inhibiting the proliferation, invasion, and tumorigenesis of HCC by regulating TGF-β1 in vitro and in vivo. These observations indicate that miR-663a may be a suitable diagnostic, therapeutic, and prognostic target for the treatment of HCC.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5016-z) contains supplementary material, which is available to authorized users.

MicroRNA‑663 inhibits the proliferation and invasion of clear cell renal cell carcinoma cells by directly targeting PAK4

Accumulating evidence has demonstrated that microRNAs (miRNAs) are key gene regulators and are abnormally expressed in clear cell renal cell carcinoma (ccRCC). The dysregulation of miRNAs has been implicated in the initiation and progression of ccRCC. Therefore, identification of ccRCC‑associated miRNAs may facilitate the determination of promising therapeutic targets for anti‑cancer treatment. In the present study, miRNA‑663 (miR‑663) expression was downregulated in ccRCC tissues and cell lines. Functional experiments suggested that restoration of miR‑663 expression inhibited the proliferation and invasion of ccRCC cells. In addition, p21 activated kinase 4 (PAK4) was validated as a direct target of miR‑663 in ccRCC cells. PAK4 was upregulated in ccRCC tissues, and the expression level of PAK4 was inversely correlated with the miR‑663 expression level. PAK4 restoration partially attenuated the suppressive roles of miR‑663 overexpression on the proliferation and invasion of ccRCC cells. The present results provide novel insight into the mechanism underlying the occurrence and development of ccRCC, suggesting that the miR‑663/PAK4 axis may be a novel therapeutic target for treatment of patients with ccRCC.

MicroRNA-663b promotes cell proliferation and epithelial mesenchymal transition by directly targeting SMAD7 in nasopharyngeal carcinoma

MicroRNAs (miRs) serve important roles in the development of various types of human cancer, including nasopharyngeal carcinoma (NPC). In the present study, the expression levels of miR-663b in NPC were investigated and its role and underlying mechanisms were examined. Reverse transcription-quantitative polymerase chain reaction was performed to assess miR-663b expression levels in NPC tissues and C666-1 cells. TargetScan was applied to predict the putative targets of miR-663b and the dual luciferase reporter assay was used to confirm the predictions. To investigate the role of miR-663b in NPC, the NPC C666-1 cell line was transfected with miR-663b mimics, miR-663b inhibitors or negative control. The Cell Counting kit-8 assay was performed for cell proliferation detection and western blot analysis was applied to determine the expression levels of epithelial mesenchymal transition (EMT)-associated proteins. Results indicated that when compared with the adjacent normal tissues and the normal nasopharyngeal epithelial cells, miR-663b expression levels were significantly upregulated in the NPC tissues and the NPC cells (P<0.01). Notably, SMAD7 is a target gene of miR-663b and may be inhibited by miR-663b. Results indicated that NPC cell proliferation was significantly promoted by miR-663b mimics and significantly inhibited by miR-663b inhibitors (P<0.05 and P<0.01). In addition, the results indicated that, when compared with the negative control group the expression levels of E-cadherin were significantly decreased, whereas the expression levels of N-cadherin, Vimentin and matrix metalloproteinase-9 were significantly increased in the cells of the miR-663b mimics group (P<0.05 and P<0.01). However, cells in the miR-663b inhibitors group exhibited the opposite effects. In conclusion, the results of the present study indicated that miR-663b functions as a tumor promoter in NPC via promoting NPC cell proliferation and EMT by directly targeting SMAD7.