MicroRNA-148b suppresses proliferation, migration, and invasion of nasopharyngeal carcinoma cells by targeting metastasis-associated gene 2

Mutual Regulation of ncRNAs and Chromatin Remodeling Complexes in Normal and Pathological Conditions

Chromatin remodeling is the one of the main epigenetic mechanisms of gene expression regulation both in normal cells and in pathological conditions. In recent years, a growing number of investigations have confirmed that epigenetic regulators are tightly connected and form a comprehensive network of regulatory pathways and feedback loops. Genes encoding protein subunits of chromatin remodeling complexes are often mutated and change their expression in diseases, as well as non-coding RNAs (ncRNAs). Moreover, different mechanisms of their mutual regulation have already been described. Further understanding of these processes may help apply their clinical potential for establishment of the diagnosis, prognosis, and treatment of the diseases. The therapeutic targeting of the chromatin structure has many limitations because of the complexity of its regulation, with the involvement of a large number of genes, proteins, non-coding transcripts, and other intermediary molecules. However, several successful strategies have been proposed to target subunits of chromatin remodeling complexes and genes encoding them, as well as the ncRNAs that regulate the operation of these complexes and direct them to the target gene regions. In our review, we focus on chromatin remodeling complexes and ncRNAs, their mutual regulation, role in cellular processes and potential clinical application.

Diagnostic, Prognostic, and Therapeutic Value of miR-148b in Human Cancers

MicroRNAs (miRs) is a class of conserved, small, noncoding RNA molecules that modulate gene expression post-transcriptionally. miR-148b is a member of miR- 148/152 family generally known to be a tumor suppressor via its effect on different signaling pathways and regulatory genes. Aberrant expression of miR-148b has recently been shown to be responsible for tumorigenesis of several different cancer types. This review discusses the current evidence regarding the involvement of miR-148b expression in human cancers and its potential clinical importance for tumor diagnosis, prognosis, and therapeutics.

miRNA-148b and its role in various cancers

miRNA-148b belongs to the family miR-148/-152, with significant differences in nonseed sequences, which can target diverse mRNA molecules. Reportedly, it may undergo deregulation in lung and ovarian cancers and downregulation in gastric, pancreatic and colon cancers. However, there is a need for further studies to better characterize its mechanism of action and in different types of cancer. In this review, we focus on the aberrant expression of miR-148b in different cancer types and highlight its main target genes and signaling pathways, as well as its pathophysiologic role and relevance to tumorigenesis in several types of cancer.

Regulators at Every Step-How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial-mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

Advances in targeted therapy mainly based on signal pathways for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma of the head and neck region which mainly distributes in southern China and Southeast Asia and has a crucial association with the Epstein-Barr virus. Based on epidemiological data, both incidence and mortality of NPC have significantly declined in recent decades grounded on the improvement of living standard and medical level in an endemic region, in particular, with the clinical use of individualized chemotherapy and intensity-modulated radiotherapy (IMRT) which profoundly contributes to the cure rate of NPC patients. To tackle the challenges including local recurrence and distant metastasis in the current NPC treatment, we discussed the implication of using targeted therapy against critical molecules in various signal pathways, and how they synergize with chemoradiotherapy in the NPC treatment. Combination treatment including targeted therapy and IMRT or concurrent chemoradiotherapy is presumably to be future options, which may reduce radiation or chemotherapy toxicities and open new avenues for the improvement of the expected functional outcome for patients with advanced NPC.

H19/miR-675-5p Targeting SFN Enhances the Invasion and Metastasis of Nasalpharyngeal Cancer Cells

AIMS

The aim is to study the role of miR-675-5p coded by long non-coding RNA H19 in the development of Nasopharyngeal Cancer (NPC) and whether miR-675-5p regulates the invasion and metastasis of NPC through targeting SFN (14-3-3σ). The study further validated the relationship between H19, miR-675-5p and SFN in NPC and their relationship with the invasion and metastasis of NPC.

METHODS

Western blot was used to detect the expression of 14-3-3σ protein in immortalized normal nasopharyngeal epithelial cells NP69 and different metastatic potential NPC cells, 6-10B and 5-8F. At the same time, to find out the relationship between 14-3-3σ protein and the expression of H19 and miR-675-5p, the expression of H19 and miR-675-5p in normal nasopharynx epithelial cells NP69 and varied nasopharyngeal carcinoma cells 6-10B and 5-8F were quantified by real-time PCR. MiR-675-5p mimic and inhibitor were transfected into NPC 6-10B to over-express and down-express miR-675-5p; miR-675-5p mimic negative control and inhibitor negative control were transfected into NPC 6-10B as control groups. The effect of over-expression and down-expression by miR-675-5p on the expression of 14-3-3σ protein was detected by Western blotting. The 3'-UTR segments of SFN, containing miR-675-5p binding sites were amplified by PCR and the luciferase activity in the transfected cells was assayed to detect whether SFN is the direct target of miR-675-5p. Transwell and scratch assays were used to verify the changes in NPC invasion and metastasis ability of mimics and inhibitors transfected with miR-675-5p.

RESULTS

The expression of 14-3-3σ protein in normal nasopharynx epithelial cells NP69 is significantly higher than in varied nasopharyngeal carcinoma cells, 6-10B and 5-8F (P<0.05), and the 14-3-3σ protein levels in low-metastatic nasopharyngeal carcinoma cell 6-10B is higher than in high-metastatic nasopharyngeal carcinoma cell 5-8F. The expression of H19 and miR-675-5p are significantly higher in NPC cells than in NP69 cell (P<0.05). The expression of H19 and miR-675-5p in high-Metastatic nasopharyngeal carcinoma cell 5-8F was higher than in low-Metastatic nasopharyngeal carcinoma cell 6-10B. The expression of 14-3-3σ protein in miR-675-5p mimic cells was significantly lower than in mimic NC (negative control) group and blank control group. However, compared with the blank control group, mimic NC showed no significant difference in 14-3-3σ protein between the two groups. The miR-675-5p inhibitor group was significantly higher than the inhibitor NC group and the blank control group (p<0.05), but there was no significant difference in the expression of 14-3-3σ protein in the inhibitor NC group and the blank control group (p>0.05). Dual-luciferase reporter assay system shows the 3'-UTR segments of SFN containing miR-675-5p binding sites. SFN was the target gene of miR-675-5p.

CONCLUSION

14-3-3σ is downregulated in NPC and is involved in the development of NPC. H19 and miR- 675-5p are upregulated in NPC, which is related to the development of NPC. The over-expression of miR- 675-5p inhibits the expression of 14-3-3σ protein. SFN is the target gene of miR-675-5p. MiR-675-5p targets SFN, downregulates its protein expression and promotes the invasion and metastasis of NPC.

MafF Is Regulated via the circ-ITCH/miR-224-5p Axis and Acts as a Tumor Suppressor in Hepatocellular Carcinoma

MafF is a member of the basic leucine zipper (bZIP) transcription factor Maf family and is commonly downregulated in multiple cancers. But the expression and function of MafF in hepatocellular carcinoma (HCC) remain unclear. In this study, we investigated the relationship between endogenous MafF expression and HCC progression and explored the regulatory mechanism of MafF expression in HCC. We found that MafF decreased in HCC tissues and cells. Lentivirus-mediated MafF overexpression inhibited HCC cell proliferation and induced cell apoptosis. Bioinformatics analysis and luciferase assay identified MafF as a direct target of miR-224-5p. RNA pull-down assay demonstrated that circular RNA circ-ITCH could sponge miR-224-5p specifically in HCC. The rescue experiments further elucidated that the expression and antitumor effects of MafF could be regulated via the circ-ITCH/miR-224-5p axis. This study verified that MafF acted as a tumor suppressor in HCC and revealed the upstream regulation mechanism of MafF, which provided a new perspective for potential therapeutic targets of HCC.

Tumor-educated platelet miR-34c-3p and miR-18a-5p as potential liquid biopsy biomarkers for nasopharyngeal carcinoma diagnosis

Background: Nasopharyngeal carcinoma (NPC) is the common malignant tumor of nasopharynx in southern China and other southeastern Asian countries. MicroRNAs (miRNAs) have been shown to play important roles in carcinogenesis. Recently, miR-34c-3p and miR-18a-5p have been found to be involved in carcinogenesis of NPC. Furthermore, platelets in NPC patients may acquire RNAs from NPC cells and turn into “tumor-educated platelet (TEP)”, which may serve as potential biomarkers for a diagnosis of NPC. However, the expression profiles of TEP miR-34c-3p and miR-18a-5p in NPC patients and their diagnostic values are yet to be determined.

Aims: To investigate expression levels of TEP miR-34c-3p and miR-18a-5p and determine their diagnostic values for NPC.

Materials and methods: Relative quantitative real-time PCR was used to determine the expression levels of TEP miR-34c-3p and miR-18a-5p in NPC patients (n=54) as compared to normal subjects (n=36). The receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic values of TEP miR-34c-3p and miR-18a-5p for NPC.

Results: The expression levels of TEP miR-34c-3p and miR-18a-5p were significantly higher in NPC patients as compared to healthy subjects. The ROC analysis showed that the area under the ROC curve (AUC), sensitivity, specificity and accuracy for TEP miR-34c-3p, miR-18a-5p, or a combination of both miRNAs for NPC diagnostic tests were 0.952, 94.44%, 86.11%, 91.11%, or 0.884, 85.19%, 86.11%, 85.55%, or 0.954, 92.59%, 86.11%, 90.00%, respectively. No correlation was found between expression levels of TEP miR-34c-3p or miR-18a-5p and patients’ demographic variables and their NPC tumor/node/metastasis stages. The positive rates of TEP miR-34c-3p and miR-18a-5p for NPC diagnosis were 93.8% and 87.5%, respectively, which were significantly higher than Epstein-Barr virus DNA with a positive rate of 66.7%.

Conclusion: The expression levels of TEP miR-34c-3p and miR-18a-5p are upregulated in NPC, rendering a significant clinical value for NPC diagnosis. The TEP miRNAs might serve as a novel type of liquid biopsies for NPC diagnosis.

The regulatory network of nasopharyngeal carcinoma metastasis with a focus on EBV, lncRNAs and miRNAs

Metastasis of nasopharyngeal carcinoma (NPC) remains a main cause of death for NPC patients even though great advances have been made in therapeutic approaches. An in-depth study into the molecular mechanisms of NPC metastasis will help us combat NPC. Epstein-Barr virus (EBV) infection is an evident feature of nonkeratinizing NPC and is strongly associated with tumor metastasis. Recently, long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) have become a hot topic of research due to their epigenetic regulatory roles in NPC metastasis. The EBV products, lncRNAs and miRNAs can target each other and share several common signaling pathways, which form an interconnected, complex molecular regulatory network. In this review, we discuss the features of this regulatory network and summarize the molecular mechanisms of NPC metastasis, focusing on EBV, lncRNAs and miRNAs with updated knowledge.

Nodal regulates bladder cancer cell migration and invasion via the ALK/Smad signaling pathway

Background

Bladder cancer is the most common malignant tumor of the urinary tract. We aimed to explore the biological role and molecular mechanism of Nodal in bladder cancer.

Materials and methods

The expression of Nodal in bladder cancer tissues and cells was determined by quantitative real-time polymerase chain reaction. The effect of silencing of Nodal on cell proliferation, clone formation, and migration and invasion was evaluated by MTT cell proliferation assay, colony formation, and transwell assays, respectively. Western blot analysis was employed to detect the expression of proliferation- and invasion-related proteins and proteins involved in ALK/Smad signaling.

Results

We found that the expression of Nodal was significantly increased in bladder cancer tissues and cell lines. Downregulation of Nodal effectively weakened cell proliferation, clone formation, and cell migration and invasion abilities. The protein expression levels of CDC6, E-cadherin, MMP-2, and MMP-9 were also altered by downregulation of Nodal. Knockdown of Nodal also blocked the expression of ALK4, ALK7, Smad2, and Smad4, which are involved in ALK/Smad signaling. Additionally, the ALK4/7 receptor blocker SB431542 reversed the promotive effects of Nodal overexpression on bladder cancer cell proliferation, migration, and invasion.

Conclusion

Our study indicated that Nodal functions as an oncogene by regulating cell proliferation, migration, and invasion in bladder cancer via the ALK/Smad signaling pathway, thereby providing novel insights into its role in bladder cancer treatment.

Analysis of miR-148b expression differences in stage-I and II parosteal osteosarcoma

Expression of human serum albumin-micro RNA miR-148b in patients with stage-I and II parosteal osteosarcoma and its effect on prognosis were investigated. A total of 47 cases of fresh tissues of stage-I and II parosteal osteosarcoma and the corresponding para-carcinoma normal bone tissues resected by operation were collected; the expression of miR-148b in parosteal osteosarcoma tissues and normal bone tissues was detected, and the correlations of miR-148b expression in parosteal osteosarcoma tissues with clinicopathological parameters and prognosis were analyzed. The expression level of miR-148b in parosteal osteosarcoma tissues was significantly lower than that in para-carcinoma normal tissues (P<0.05). It was found that the low expression of miR-148b was correlated with the lung metastasis (P<0.05). Moreover, Kaplan-Meier survival curve analysis showed that the overall survival rate of patients in the low-expression miR-148b group was lower than that in the high-expression group (P<0.05). Multivariate Cox regression analysis revealed that the miR-148b level (P=0.003) was an independent prognostic factor affecting the prognosis. The results of this study showed that the expression of miR-148b in stage-I and II parosteal osteosarcoma tissues declines, which is related to the poor clinical prognosis of parosteal osteosarcoma.

miR-148b-3p inhibits gastric cancer metastasis by inhibiting the Dock6/Rac1/Cdc42 axis

Background

Our previous work showed that some Rho GTPases, including Rho, Rac1 and Cdc42, play critical roles in gastric cancer (GC); however, how they are regulated in GC remains largely unknown. In this study, we aimed to investigate the roles and molecular mechanisms of Dock6, an atypical Rho guanine nucleotide exchange factor (GEF), in GC metastasis.

Methods

The expression levels of Dock6 and miR-148b-3p in GC tissues and paired nontumor tissues were determined by immunohistochemistry (IHC) and in situ hybridization (ISH), respectively. The correlation between Dock6/miR-148b-3p expression and the overall survival of GC patients was calculated by the Kaplan-Meier method and log-rank test. The roles of Dock6 and miR-148b-3p in GC were investigated by in vitro and in vivo functional studies. Rac1 and Cdc42 activation was investigated by GST pull-down assays. The inhibition of Dock6 transcription by miR-148b-3p was determined by luciferase reporter assays.

Results

A significant increase in Dock6 expression was found in GC tissues compared with nontumor tissues, and its positive expression was associated with lymph node metastasis and a higher TNM stage. Patients with positive Dock6 expression exhibited shorter overall survival periods than patients with negative Dock6 expression. Dock6 promoted GC migration and invasion by increasing the activation of Rac1 and Cdc42. miR-148b-3p expression was negatively correlated with Dock6 expression in GC, and it decreased the motility of GC cells by inhibiting the Dock6/Rac1/Cdc42 axis.

Conclusions

Dock6 was over-expressed in GC tissues, and its positive expression was associated with GC metastasis and indicated poor prognosis of GC patients. Targeting of Dock6 by miR-148b-3p could activate Rac1 and Cdc42, directly affecting the motility of GC cells. Targeting the Dock6-Rac1/Cdc42 axis could serve as a new therapeutic strategy for GC treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0729-z) contains supplementary material, which is available to authorized users.

Dynamic Changes in Plasma MicroRNAs Have Potential Predictive Values in Monitoring Recurrence and Metastasis of Nasopharyngeal Carcinoma

Although circulating microRNAs (miRNAs) have already proven to be useful as diagnostic and prognostic biomarkers in nasopharyngeal carcinoma (NPC), the potential of these molecules to monitor patients over time has been less explored. This study aimed to analyze dynamic changes in plasma miRNAs before and after treatment and explore their clinical significance in monitoring recurrence and metastasis of NPC. Candidate miRNAs were screened by microarray analysis and validated by real-time quantitative polymerase chain reaction (RT-qPCR). In the follow-up cohort including 102 patients, blood samples (plasma) were collected before the treatment initiation, 3 months, 6 months, and 12 months after treatments, and at the time of any recurrence or metastasis. Among these plasma miRNAs, miR-9-3p, miR-124-3p, miR-892b, and miR-3676-3p were significantly upregulated (P = 0.018, P = 0.039, P = 0.001, and P = 0.01, resp.) after treatment compared with pretreatment, and the four plasma miRNAs were downregulated again at recurrence or metastasis (P < 0.001, P = 0.015, P = 0.003, and P = 0.026, resp.). The dynamic changes in plasma miRNAs after treatment reflect the outcome of the disease and have the potential to monitor recurrence and metastasis in patients with NPC.