Human papillomavirus 16 E6 modulates the expression of miR-496 in oropharyngeal cancer

The Relationship of Grade, Stage and Tobacco Usage in Head and Neck Squamous Cell Carcinoma With p53, PIK3CA and MicroRNA Profiles

BACKGROUND

 Head and neck squamous cell carcinoma (HNSCC) has multiple epigenetic modifications including post-transcriptional regulation by microRNAs (miRNAs) as well as alterations in molecular pathways due to mutations. Examining these miRNAs and location-specific molecular alterations is essential to understanding the intricacies of HNSCC and directing focused diagnoses and treatments.

AIM

 To investigate tobacco-related changes in the expression of miRNAs and proteins with clinicopathological parameters of HNSCC and disease-modifying personal habits like tobacco and alcohol use.

METHODOLOGY

 The study concentrated on oropharyngeal cancers using immunohistochemistry and reverse transcription-polymerase chain reaction. Expression of microRNAs mir15a, mir20b, mir21, mir31, mir33b, mir146a, mir155, mir218, mir363 and mir497 and immunohistochemical expression of P53 and PIK3CA were correlated with grade, stage and personal habits like tobacco and alcohol intake.

RESULTS

 mir21 and mir15a are under-expressed in higher grades with a trend towards statistical significance (P-value of 0.094 and 0.056 by one-way analysis of variance (ANOVA) on ΔCT values). mir155 and mir146a are overexpressed in stage IV tumours while mir 31 is under-expressed in stage IV tumours but statistical significance was not reached. mir497 showed overexpression in tobacco users, but these results were limited by many tumours not showing any amplification for the miRNA and statistical significance was not reached. There was no statistically significant association found between immunohistochemical expression of p53 and PIK3CA with grade, stage or personal habits.

CONCLUSION

 Through the deciphering of complex miRNA patterns and their relationships with clinicopathology, this study attempted to increase our understanding of HNSCC. Some candidate miRNAs showing probable association with grade, stage and personal habits were identified, but larger studies are needed to confirm or refute the importance of these miRNAs.

Dysregulated microRNA Expression Relevant to TERT Promoter Mutations in Tonsil Cancer-A Pilot Study

Tonsillar squamous cell carcinomas (TSCCs) exhibit high rates of human papillomavirus (HPV) positivity. The expression profiles of microRNA (miRNA), which are small RNA molecules that play pivotal roles in biological processes, in TSCC in relation to the HPV status and cancer-related genetic mutations are not well investigated. Herein, we expanded our previous research, which was focused on established clinicopathological and genetic mutational data, to profile miRNA expression in TSCC, aiming to identify clinically relevant targets for early diagnosis and therapeutic intervention. The miRNA profiles were analyzed using the nCounter Nanostring miRNA Expression assay in 22 surgically resected TSCC tissues and their contralateral normal tonsil tissues. The TERT promoter (TERTp) gene was the only relevant candidate gene associated with differentially expressed miRNAs in TSCC. Hierarchical clustering analysis revealed high expression levels of hsa-miR-1285-5p, hsa-miR-1203, hsa-miR-663a, hsa-miR-1303, hsa-miR-33a-5p, and hsa-miR-3615 coupled with low expression levels of hsa-miR-3182, hsa-miR-219a-2-3p, and hsa-miR-767-3p, which were associated with HPV-positive TSCC (p = 0.009). Functional enrichment analysis revealed that these dysregulated miRNAs tended to be involved in protein binding (molecular function) and cellular components (biological processes). Therefore, hsa-miR-1285-5p and hsa-miR-663a may be associated with HPV-positive TERTp-mutated tumors and may serve as potential treatment targets and biomarkers for early detection.

Comparison of plasma- and saliva-derived exosomal miRNA profiles reveals diagnostic potential in head and neck cancer

Background: Head and neck squamous cell carcinomas (HNSCC) lack tumor-specific biomarkers. Exosomes from HNSCC patients carry immunomodulatory molecules, and correlate with clinical parameters. We compared miRNA profiles of plasma- and saliva-derived exosomes to reveal liquid biomarker candidates for HNSCC.

Methods: Exosomes were isolated by differential ultracentrifugation from corresponding plasma and saliva samples from 11 HNSCC patients and five healthy donors (HD). Exosomal miRNA profiles, as determined by nCounter^® SPRINT technology, were analyzed regarding their diagnostic and prognostic potential, correlated to clinical data and integrated into network analysis.

Results: 119 miRNAs overlapped between plasma- and saliva-derived exosomes of HNSCC patients, from which 29 tumor-exclusive miRNAs, associated with TP53, TGFB1, PRDM1, FOX O 1 and CDH1 signaling, were selected. By intra-correlation of tumor-exclusive miRNAs from plasma and saliva, top 10 miRNA candidates with the strongest correlation emerged as diagnostic panels to discriminate cancer and healthy as well as potentially prognostic panels for disease-free survival (DFS). Further, exosomal miRNAs were differentially represented in human papillomavirus (HPV) positive and negative as well as low and high stage disease.

Conclusion: A plasma- and a saliva-derived panel of tumor-exclusive exosomal miRNAs hold great potential as liquid biopsy for discrimination between cancer and healthy as well as HPV status and disease stage. Exosomal miRNAs from both biofluids represent a promising tool for future biomarker studies, emphasizing the possibility to substitute plasma by less-invasive saliva collection.

The dynamic interactome of microRNAs and the human papillomavirus in head and neck cancers

The Human Papillomavirus type 16 is a major etiologic factor for a subset of Head and Neck cancers. These cancers of the oropharyngeal region are growing, and it is expected to exceed cervical cancers in the near future. The major oncogenes E6 and E7 mediate many of the early transformation stages targeting p53 and other tumour suppressor genes. The majority of this regulation is centred on protein coding genes but more recently small non-coding RNAs, such as miRNAs are also regulated by HPV16. However, the system-wide impact of HPV16 on miRNAs is yet to be fully understood. To fully gauge the overall relationship between HPV16 and miRNAs, several studies have devised dynamic interactomes which encompass viral oncogenes, miRNAs and gene targets. These interactomes map potential pathways which permit the identification of possible mechanistic links. Our review will discuss the latest developments in using viral interactomes to understand viral mechanisms and how these approaches may aid in the elucidation of potential druggable pathways.

miR-496 inhibits proliferation via LYN and AKT pathway in gastric cancer

MicroRNAs (miRNAs) operate as tumor suppressor or carcinogen to regulate cell proliferation, metastasis, invasion, differentiation, apoptosis, and metabolic process. In the present research, we investigated the effect and mechanism of miR-496 in human gastric cancer cells. miR-496 was downregulated in two gastric cancer cell lines, AGS and MKN45, compared with normal gastric epithelial cell line GES-1. miR-496 mimics inhibited the proliferation of AGS cells after the transfection for 48 and 72 h. The migration and invasion of AGS cells were also inhibited by the transfection of miR-496 mimics. miR-496 mimics induced the apoptosis through upregulating the levels of Bax and Active Caspase 3 and downregulating the levels of Bcl-2 and Total Caspase 3. Bioinformatics analysis showed that there was a binding site between miR-496 and Lyn kinase (LYN). miR-496 mimics could inhibit the expression of LYN in AGS cells. LYN overexpression blocked the inhibition of tumor cell growth, as well as the inhibition of AKT/mTOR signaling pathway induced by miR-496. In conclusion, miR-496 inhibited the proliferation through the AKT/mTOR signaling pathway via targeting LYN in gastric cancer cells. Our research provides a new potential target for clinical diagnosis and targeted treatment for gastric cancer.

Anti-NMDA Receptor Encephalitis, Vaccination and Virus

Anti-N-methyl-d-aspartate (Anti-NMDA) receptor encephalitis is an acute autoimmune disorder. The symptoms range from psychiatric symptoms, movement disorders, cognitive impairment, and autonomic dysfunction. Previous studies revealed that vaccination might induce this disease. A few cases were reported to be related to H1N1 vaccine, tetanus/diphtheria/pertussis and polio vaccine, and Japanese encephalitis vaccine. Although vaccination is a useful strategy to prevent infectious diseases, in a low risk, it may trigger serious neurological symptoms. In addition to anti-NMDA receptor encephalitis, other neurological diseases were reported to be associated with a number of vaccines. In this paper, the anti-NMDA receptor encephalitis cases related to a number of vaccines and other neurological symptoms that might be induced by these vaccines were reviewed. In addition, anti-NMDA receptor encephalitis cases that were induced by virus infection were also reviewed.

The Circular RNA circRNA124534 Promotes Osteogenic Differentiation of Human Dental Pulp Stem Cells Through Modulation of the miR-496/β-Catenin Pathway

Circular RNAs (circRNAs) have been found to be a crucial role in stem cell-associated bone regeneration. However, the functions and underlying mechanisms of circRNAs in the osteogenic differentiation of human dental pulp stem cells (hDPSCs) remain largely unclear. We found that overexpression of circRNA124534 unexpectedly promoted DPSCs osteogenesis in vitro and in vivo. Our results confirmed circRNA124534, acting as a miRNA sponge, directly interacts with miR-496 and consequently regulates β-catenin, which in turn exerts osteogenesis of DPSCs. Enforced expression of miR-496 reversed the osteogenesis of circRNA124534, and suppression of miR-496 enhanced the osteogenic differentiation of DPSCs by promoting β-catenin. In conclusion, our findings demonstrate functions of circRNA124534 in modulating osteogenic differentiation through the miR-496/β-catenin pathway; thus, providing a novel potential target for therapy.

MicroRNA-496 suppresses tumor cell proliferation by targeting BDNF in osteosarcoma

MicroRNAs (miRNAs) are integrally involved in biological and pathobiological development. Many studies have demonstrated the abnormal expression of microRNA-496 (miR-496) in various human malignant tumors. The present study was designed to investigate the functions and the underlying mechanisms of miR-496 in osteosarcoma (OS) progression. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to determine the expression of miR-496 in OS tissues and cell lines. Luciferase activity was used to confirm the interaction between miR-496 and brain derived neurotrophic factor (BDNF), a downstream gene of miR-496. RT-qPCR was also used to quantify BDNF mRNA expression, and the BDNF protein expression level was detected by western blot analysis. In addition, the Cell Counting Kit-8 (CCK-8) was used to detect cell viability. The results revealed that the level of miR-496 expression was significantly reduced in osteosarcoma tissues and cell lines. BDNF was verified to be a direct target gene of miR-496 and was found to be negatively regulated by miR-496. Overall, it was demonstrated that miR-496 inhibits osteosarcoma cell proliferation via inhibition of BDNF. Thus, the miR-496/BDNF axis may be a novel strategy for the clinical treatment of OS.

miR-496 suppress tumorigenesis via targeting BDNF-mediated PI3K/Akt signaling pathway in non-small cell lung cancer

microRNA-496 (miR-496) was found expressed abnormally in non-small cell lung cancer (NSCLC). But the study about the role of miR-496 on NSCLC was not satisfactory in date. Therefore, here we designed to explore the role of miR-496 and the probable internal mechanism in tumorigenesis of NSCLC. Increasing miR-496 both in NSCLC patients and cell lines could significantly restrained cell proliferation. For farther researching the regulation mechanism of miR-496 on NSCLC, we screen Brain derived neurotrophic factor (BDNF) as a potential target of miR-496 by bioinformatic methods and predicted a possible target of miR-496 in the 3'untranslated region (UTR) of miR-496. In clinical patients and most NSCLC cell lines including H1650, H292, H1944 and A549, increasing expression of miR-496 suppressed tumor growth via inactivating BDNF-mediated PI3K/Akt signaling pathway activation. In a word, our fingdings first represent a mechanism of miR-496 on NSCLC tumor growth via inactivating BDNF-mediated PI3K/Akt signaling pathway.

MiR-496 promotes migration and epithelial-mesenchymal transition by targeting RASSF6 in colorectal cancer

Aberrant loss of tumor-suppressor genes plays a crucial role in tumorigenesis and development of colorectal cancer (CRC). Extensive studies have reported tha hypermethylation of Ras association domain family member 6 (RASSF6) is common in various solid tumors. Another important mode of epigenetic regulation, microRNA (miRNA) regulation of RASSF6, is far from clear. The aim of the present work was to screen out novel miRNA regulating RASSF6, and to explore its underlying mechanism in CRC. With the use of bioinformatics, clinical sample data, and luciferase binding assay, we determined that microRNA-496 (miR-496) could be a novel oncomiR that directly binds to RASSF6. Next, a series of miR-496 mimics or inhibitor, or RASSF6 small interfering RNA (siRNA) introduced into CRC cells were applied to examine the effect of miR-496 on CRC cell viability, migration, and epithelial-mesenchymal transition (EMT). The results demonstrated that miR-496/RASSF6 could promote cell migration and EMT via Wnt signaling activation, but had no effect on cell viability. Our results confirmed that the miR-496/RASSF6 axis is involved in Wnt pathway-mediated tumor metastasis, highlighting its potential as a therapeutic target for CRC.

Up-regulation of microRNA-496 suppresses proliferation, invasion, migration and in vivo tumorigenicity of human osteosarcoma cells by targeting eIF4E

Osteosarcoma is an aggressive bone tumor characterized by a high level of genetic instability and recurring DNA deletions and amplifications. This study aims to investigate how microRNA-496 (miR-496) affects proliferation, invasion, and migration of human osteosarcoma (OS) cells and in vivo tumorigenicity by targeting eukaryotic translation initiation factor 4E (eIF4E). Microarray-based gene expression profiling involving OS was used in order to identify differentially expressed genes. After that, the interaction between miR-496 expression and OS patients' survival rate was determined. The expression pattern of miR-496 and eIF4E was determined in OS tissues and cells, and their potential relationship was further analyzed by using the dual luciferase reporter gene assay. With the purpose of identifying the functional role miR-496 in OS, cell proliferation, migration, and invasion were measured in cells treated with miR-496 mimic or inhibitor. A nude mouse model was constructed in order to investigate the regulatory effects of miR-496 on tumor growth in vivo by regulating eIF4E. OS cells exhibited a down-regulated expression of miR-496 and an up-regulated expression of eIF4E. miR-496 expression was positively correlated to OS patients' survival rate. Bioinformatics analysis suggested eIF4E would be a direct target of miR-496, and the expression of eIF4E was inhibited by overexpression of miR-496. miR-496 elevation was found to exert suppressive effects on OS cell proliferation, migration and invasion in vitro and tumor growth in vivo, with the effects being reversed using miR-496 depletion. Altogether, the above findings support a conclusion that miR-496 could work as a tumor suppressor in OS through down-regulation of eIF4E. This study may provide a novel target for treatment of OS.