Dysregulation of cellular microRNAs by human oncogenic viruses - Implications for tumorigenesis

Epigenetic Factor MicroRNAs Likely Mediate Vaccine Protection Efficacy against Lymphomas in Response to Tumor Virus Infection in Chickens through Target Gene Involved Signaling Pathways

Epigenetic factors, including microRNAs (miRNAs), play an important role in affecting gene expression and, therefore, are involved in various biological processes including immunity protection against tumors. Marek's disease (MD) is a highly contagious disease of chickens caused by the MD virus (MDV). MD has been primarily controlled by vaccinations. MD vaccine efficacy might, in part, be dependent on modulations of a complex set of factors including host epigenetic factors. This study was designed to identify differentially expressed miRNAs in the primary lymphoid organ, bursae of Fabricius, in response to MD vaccination followed by MDV challenge in two genetically divergent inbred lines of White Leghorns. Small RNA sequencing and bioinformatic analyses of the small RNA sequence reads identified hundreds of miRNAs among all the treatment groups. A small portion of the identified miRNAs was differentially expressed within each of the four treatment groups, which were HVT or CVI988/Rispens vaccinated line 63-resistant birds and line 72-susceptible birds. A direct comparison between the resistant line 63 and susceptible line 72 groups vaccinated with HVT followed by MDV challenge identified five differentially expressed miRNAs. Gene Ontology analysis of the target genes of those five miRNAs revealed that those target genes, in addition to various GO terms, are involved in multiple signaling pathways including MAPK, TGF-β, ErbB, and EGFR1 signaling pathways. The general functions of those pathways reportedly play important roles in oncogenesis, anti-cancer immunity, cancer cell migration, and metastatic progression. Therefore, it is highly likely that those miRNAs may, in part, influence vaccine protection through the pathways.

MiR-150 and miR-155 expression predicts survival of cervical cancer patients: a translational approach to novel prognostic biomarkers

INTRODUCTION

High-risk human papillomavirus (HPV) is the aetiological agent of cervical cancer, which remains the fourth leading cause of cancer death in women worldwide. K14-HPV16 transgenic mice are a model for HPV-induced cancers, which undergo multistep squamous carcinogenesis at the skin, that is histologically and molecularly similar to carcinogenesis of the human cervix. Previous screens of differentially regulated microRNAs (miRs) using K14-HPV16 mice showed a role for miR-21, miR-155, miR-150, miR-146a, miR-125b and miR-223 during carcinogenesis.

METHODS

We now aim to translate these observations into the clinical setting, using data provided by The Cancer Genome Atlas (TCGA) to explore whether those microRNAs can influence the survival of cervical cancer patients.

RESULTS

Results showed that low miR-150, miR-155 and miR-146a expression levels in primary tumours were associated with poor overall survival. However, only miR-150 and miR-155 were found to be independent predictors, increasing the risk of death. When patients were stratified by clinical stage, low miR-150, miR-155, miR-146a and miR-125b were associated with poor survival for clinical stages I and II. Only low miR-150 expression increased the death risk.

CONCLUSION

We conclude that miR-150 and miR-155 may be potentially applied as prognostic biomarkers in cervical cancer patients. However, further investigation is required to determine their applicability.

Characterizing the Inflammatory Microenvironment in K14-HPV16 Transgenic Mice: Mast Cell Infiltration and MicroRNA Expression

High-risk human papillomavirus (HPV) is the etiologic agent of several types of cancer. Mast cells’ role as either a driving or opposing force for cancer progression remains controversial. MicroRNAs are dysregulated in several HPV-induced cancers, and can influence mast cell biology. The aim of this study was to evaluate mast cell infiltration and to identify microRNAs potentially regulating this process. Transgenic male mice (K14-HPV16; HPV+) and matched wild-type mice (HPV−) received 7,12-Dimethylbenz[a]anthracene (DMBA) (or vehicle) over 17 weeks. Following euthanasia, chest skin and ear tissue samples were collected. Mast cell infiltration was evaluated by immunohistochemistry. MicroRNAs associated with mast cell infiltration were identified using bioinformatic tools. MicroRNA and mRNA relative expression was evaluated by RT-qPCR. Immunohistochemistry showed increased mast cell infiltration in HPV+ mice (p < 0.001). DMBA did not have any statistically significant influence on this distribution. Ear tissue of HPV+ mice showed increased mast cell infiltration (p < 0.01) when compared with chest skin samples. Additionally, reduced relative expression of miR-125b-5p (p = 0.008, 2−ΔΔCt = 2.09) and miR-223-3p (p = 0.013, 2−ΔΔCt = 4.42) seems to be associated with mast cell infiltration and increased expression of target gene Cxcl10. These results indicate that HPV16 may increase mast cell infiltration by down-regulating miR-223-3p and miR-125b-5p.

Molecular Markers in Urinary Bladder Cancer: Applications for Diagnosis, Prognosis and Therapy

Cancer of the urinary bladder is a neoplasm with considerable importance in veterinary medicine, given its high incidence in several domestic animal species and its life-threatening character. Bladder cancer in companion animals shows a complex and still poorly understood biopathology, and this lack of knowledge has limited therapeutic progress over the years. Even so, important advances concerning the identification of tumour markers with clinical applications at the diagnosis, prognosis and therapeutic levels have recently been made, for example, the identification of pathological BRAF mutations. Those advances are now facilitating the introduction of targeted therapies. The present review will address such advances, focusing on small animal oncology and providing the reader with an update on this field. When appropriate, comparisons will be drawn with bladder cancer in human patients, as well as with experimental models of the disease.

Evaluation of microRNAs as potential biomarkers in circulating HPV-DNA-positive non-small cell lung cancer patients

The aim of the present study was to identify the potential risk of circulating-HPV-DNA in non-small cell lung cancer (NSCLC) and to analyze abnormally expressed miRNAs in circulating HPV-DNA-positive NSCLC. HPV universal primers were used to detect the presence of HPV-DNA in the peripheral blood of 100 patients with NSCLC. The relationship between circulating-HPV-DNA and NSCLC patients characteristics was analyzed. Then, eight differentially expressed miRNAs in NSCLC were screened based on the TCGA database. The levels of miRNAs in circulating HPV-DNA-positive NSCLC patients were detected by real-time quantitative PCR. ROC curves were generated to evaluate the diagnostic performance. Circulating-HPV-DNA was found in 16 patients. The proportion of HPV-DNA-positive patients with poorly differentiated NSCLC, advanced lung cancer and lymph node metastasis was higher than that of HPV-DNA-negative patients. The levels of miR-183, miR-210 and miR-182 were significantly higher and miR-144 was significantly lower in HPV-DNA-positive NSCLC than those in HPV-DNA-negative NSCLC patients. When using a single miRNA to identify circulating HPV-DNA-positive NSCLC patients, miR-210 had a higher area under the ROC curve (AUC) than other miRNAs, and its sensitivity and specificity were also higher. In addition, the combination of two miRNAs was more effective than a single miRNA. Among them, miR-210+ miR-144 had the highest AUC value and showed the best prediction performance. Circulating-HPV-DNA may serve as a risk factor in NSCLC. Plasma miR-183, miR-210, miR-182 and miR-144 can be used as reliable biomarkers to identify circulating HPV-DNA-positive NSCLC.

MicroRNA-145 overexpression inhibits neuroblastoma tumorigenesis in vitro and in vivo

Neuroblastoma (NB) is responsible for 15% of all childhood cancer deaths. Despite advances in treatment and disease management, the overall 5-year survival rates remain poor in high-risk disease (25-40%). It is well known that miR-145 functions as a tumor suppressor in several types of cancer. However, the impact of miR-145 on NB is still ambiguous. Our aim was to investigate the potential tumor suppressive role and mechanisms of miR-145 in high-risk neuroblastoma. Expression levels of miR-145 in tissues and cells were determined using RT-qPCR. The effect of miR-145 on cell viability was evaluated using MTT assays, apoptosis levels were determined using TUNEL staining, and the MTDH protein expression was determined using western blot and RT-PCR. Luciferase reporter plasmids were constructed to confirm direct targeting for MTDH. The results showed that miR-145 expression was significantly lower in high-risk MYCN amplified (MNA) tumors and low miR-145 expression was associated with worse EFS and OS in our cohort. Over-expression of miR-145 reduced cell viability and increased apoptosis in SH-SY-5Y cells. We identified MTDH as a direct target for miR-145 in SH-SY-5Y cells. Targeting MTDH has the similar results as miR-145 overexpression. Our findings suggest that low miR-145 expression was associated with poor prognosis in patients with NB, and the overexpression of miR-145 inhibited NB cells growth by down-regulating MTDH, thus providing a potential target for the development of microRNA-based approach for NB therapy.

Effects of Wnt/β-Catenin Signal Pathway Regulated by miR-342-5p Targeting CBX2 on Proliferation, Metastasis and Invasion of Ovarian Cancer Cells

Objective

This study aimed to investigate the effect of Wnt/β-catenin signal pathway mediated by miR-342-5p targeting CBX2 gene on the proliferation, metastasis, invasion and apoptosis of ovarian cancer cells, and to explore its related regulatory mechanism.

Methods

Human normal ovarian epithelial cell line IOSE80, human ovarian cancer cell line SKOV3 and OVCAR3 were the subjects. Software were used to predict the binding site of miR-342-5p targeting CBX2 gene. The proliferation rate of ovarian cancer cells was detected by MTT method; the cell viability of each group was observed by colony formation test; the apoptosis of cells in each group was detected by flow cytometry; the invasive ability of cells was determined by transwell test, and the migration ability of cells was detected by scratch test. The mRNA expression levels of miR-342-5p, CBX2, Wnt1, β-catenin, C-myc and Cyclin D1 were measured by qRT-PCR. Also, Western blot was used to determine the protein expression levels of CBX2, Wnt1, β-catenin, C-myc and Cyclin D1.

Results

CBX2 was identified as the target gene of miR-342-5p. MTT test results showed that miR-342-5p could significantly inhibit the proliferation of SKOV3 and OVCAR3 cells, colony formation assay results indicated that the viability of SKOV3 and OVCAR3 cells transfected with miR-342-5p decreased significantly, and flow cytometry results suggested that miR-342-5p could promote the apoptosis of SKOV3 and OVCAR3 cells. Also, the results of transwell showed that miR-342-5p could significantly inhibit the invasive ability of SKOV3 and OVCAR3 cells, and the results of scratch assay suggested that miR-342-5p could significantly inhibit the migration of SKOV3 and OVCAR3 cells. Moreover, qRT-PCR and Western blot results indicated that the mRNA and protein expression levels of CBX2, Wnt1, β-catenin, C-myc and Cyclin D1 decreased in SKOV3 and OVCAR3 cells transfected with miR-342-5p, while the mRNA expression levels of miR-342-5p increased significantly (P<0.05).

Conclusion

MiR-342-5p targeted gene is CBX2, which can significantly reduce the proliferation, invasion, migration and viability of ovarian cancer cell lines SKOV3 and OVCAR3, and promote their apoptosis. The mechanism may be related to the mediation of Wnt/β-catenin signal pathway and down-regulation of the related genes expression.

High miR-454-3p expression predicts poor prognosis in hepatocellular carcinoma

Purpose: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the clinic all over the world, which has become a public health challenge. The T/N/M staging system plays a core role in HCC prognosis. However, it cannot precisely stratify the risk of HCC prognosis. MiR-454-3p plays an important role in the progression of tumors. Therefore, we need to develop more reliable prognostic markers for HCC patients which can focus on miR-454-3p. Methods: We used Chi-square and Fisher exact tests to assess correlations between miR-454-3p expression and clinical parameters in liver cancer patients from The Cancer Genome Atlas database (TCGA). Then, Cox regression analysis, Kaplan-Meier curve, and log-rank test were used to compare the difference of survival between the high-expression group and low-expression group, and P value was included. Finally, we used TCGA data set to carry out gene enrichment analysis. Results: In this research, the expression of miR-454-3p increased in HCC and was associated with patient survival, G3/G4 staging, III/IV staging and T staging. Higher miR-454-3p expressed patients had shorter survival time. Besides, mitotic spindle, G2M checkpoint, and E2F targets were differentially enriched in miR-454-3p high-expression phenotype by Gene set enrichment analysis. Conclusion: Overexpression of miR-454-3p may be a significant and independent predictor of poor prognosis in HCC patients.

The Role of MicroRNAs in the Metastatic Process of High-Risk HPV-Induced Cancers

High-risk human papillomavirus (HPV)-driven cancers represent a major health concern worldwide. Despite the constant effort to develop and promote vaccination against HPVs, there is still a high percentage of non-vaccinated population. Furthermore, secondary prevention programs are not ubiquitous worldwide and not widely followed. Metastatic disease is the cause of the great majority of cancer-associated deaths, making it essential to determine its underlying mechanisms and to identify actionable anti-metastatic targets. Within certain types of cancer (e.g., head and neck), HPV-positive tumors show different dissemination patterns when compared with their HPV-negative counterparts, implicating HPV-related factors in the metastatic process. Among the many groups of biomolecules dysregulated by HPV, microRNAs have recently emerged as key regulators of carcinogenesis, able to control complex processes like cancer metastization. In this review, we present recent data on the role of microRNAs in the metastization of HPV-related cancers and on their possible clinical relevance as biomarkers of metastatic disease and/or as therapeutic targets.

The role of miR-106p-5p in cervical cancer: from expression to molecular mechanism

This study aims to investigate the role of miR-106b-5p in cervical cancer by performing a comprehensive analysis on its expression and identifying its putative molecular targets and pathways based on The Cancer Genome Atlas (TCGA) dataset, Gene Expression Omnibus (GEO) dataset, and literature review. Significant upregulation of miR-106b-5p in cervical cancer is confirmed by meta-analysis with the data from TCGA, GEO, and literature. Moreover, the expression of miR-106b-5p is significantly correlated with the number of metastatic lymph nodes. Our bioinformatics analyses show that miR-106b could promote cervical cancer progression by modulating the expression of GSK3B, VEGFA, and PTK2 genes. Importantly, these three genes play a crucial role in PI3K-Akt signaling, focal adhesion, and cancer. Both the expression of miR-106b-5p and key genes are upregulated in cervical cancer. Several explanations could be implemented for this upregulation. However, the specific mechanism needs to be investigated further.