Search

Background/Aim: Canine mammary gland tumors (MGTs), as a potential model of human breast cancer, have a well-defined histological classification system. MicroRNA (miRNA) expression is a key part of the molecular signatures of both MGTs and human breast cancer, although the signatures alone do not yet provide a sufficient basis for definitive diagnosis. In this study, we investigated the association between miRNA expression patterns and histological classification. Materials and Methods: Mammary gland tissue was collected from healthy dogs (n=7) and dog patients (n=80). Further samples (n=5) were obtained from established MGT cell lines. We targeted miRNAs differentially expressed in metastatic tumor tissue versus non-metastatic and normal tissue. A subset of samples was analyzed using small RNA next generation sequencing (NGS) with subsequent qPCR. Results: Six differentially expressed miRNAs were selected from the NGS analysis and submitted for large-scale qPCR. The large-scale qPCR analysis revealed greater alternations in miRNA expression. Large-scale analysis, based on 79 samples, revealed a hierarchical clustering based on selected miRNAs that did not strikingly match the histopathological subtype classification. Conclusion: We successfully investigated the large-scale miRNA expression pattern in canine MGT and provided the whole miRNA expression. The selected miRNA demonstrated that there is no straightforward mapping between molecular signatures and histological classification of canine MGTs at the miRNA level. [ABSTRACT FROM AUTHOR]

Considering the importance of the canine cancer model of human disease, as well as the need for strategies for canine cancer management, the properties of exosomes are an emerging topic in canine oncology. In our study, exosomal RNA was isolated and investigated by next‐generation sequencing. We identified several differentially expressed microRNAs (miRNAs/miRs) in the exosomes of two melanoma cell lines compared with non‐tumor reference exosomes. We explored these potential melanoma‐specific exosomal miRNAs further and found that miR‐143 and let‐7b increased in primary, whereas miR‐210, 708, 221, and 222 increased in metastatic site originated melanoma cells. Further analysis showed miR‐143 and 221 significantly increased in plasma exosomes of metastatic melanoma patients. Moreover, the sensitivity and specificity are >85% for differentiating the non‐metastatic and metastatic patients. Therefore, these miRNAs can be an incredible biomarker candidate to identify metastatic melanoma and facilitate a better prognosis. [ABSTRACT FROM AUTHOR]

Among small non‐coding RNAs (sncRNAs/sRNAs), the functional regulation of microRNAs (miRNAs) has been studied in canine oral melanoma (COM). However, the expression level of other sncRNAs, like small nucleolar RNAs (snoRNAs), small nuclear RNAs (snRNAs), transfer RNA‐derived fragments (tRFs) and PIWI‐interacting RNAs (piRNAs), in COM is unknown. The aim of this study was to investigate sncRNAs other than miRNAs in COM from our small RNA sequencing project (PRJNA516252). We found that several snRNAs and piRNAs were upregulated, whereas tRFs and snoRNAs were downregulated in COM. Upregulation of U1 snRNA and piR‐972, and downregulation of tRNA‐ser (1) and snoRA24 was confirmed in dog melanoma tissue and cell lines by quantitative reverse transcription PCR. Consistently, the expression of tRNA‐ser (1) and snoRA24 in plasma of COM cases was also decreased. Finally, we found a similar expression trend of U1 and snoRA24 in the human cutaneous melanoma cell line, MEWO, compared with human epidermal melanocyte cells (HEMa‐Lp). In our study, snRNA, snoRNA, tRFs and piRNA were dysregulated during melanoma progression. Moreover, the melanoma‐associated expression of U1 and snoRA24 was similar in human and dog melanoma. [ABSTRACT FROM AUTHOR]

Mastitis is a common inflammatory infectious disease in dairy cows. To understand the microRNA (miRNA) expression profile changes during bovine mastitis, we undertook a genome‐wide miRNA study of normal milk and milk that tested positive on the California mastitis test for bovine mastitis (CMT+). Twenty‐five miRNAs were differentially expressed (23 miRNAs upregulated and two downregulated) during bovine mastitis relative to their expression in normal milk. Upregulated mature miR‐1246 probably derived from a U2 small nuclear RNA rather than an miR‐1246 precursor. The significantly upregulated miRNA precursors and RNU2 were significantly enriched on bovine chromosome 19, which is homologous to human chromosome 17. A gene ontology analysis of the putative mRNA targets of the significantly upregulated miRNAs showed that these miRNAs were involved in binding target mRNA transcripts and regulating target gene expression, and a Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the upregulated miRNAs were predominantly related to cancer and immune system pathways. Three novel miRNAs were associated with bovine mastitis and were relatively highly expressed in milk. We confirmed that one of the novel mastitis‐related miRNAs was significantly upregulated using a digital PCR system. The differentially expressed miRNAs were involved in human cancers, infections, and immune‐related diseases. The genome‐wide analysis of miRNA profiles in this study provides insight into bovine mastitis and inflammatory diseases. Databases: The miRNAseq generated for this study can be found in the Sequence Read Archive (SRA) under BioProject Number PRJNA421075 and SRA Study Number SRP126134 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA421075). [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) dysregulation contribute the cancer pathogenesis. However, the miRNA profile of canine oral melanoma (COM), one of the frequent malignant melanoma in dogs is still unrevealed. The aim of this study is to reveal the miRNA profile in canine oral melanoma. MiRNAs profile of oral tissues from normal healthy dogs and COM patients were compared by next-generation sequencing. Along with tumour suppressor miRNAs, we report 30 oncogenic miRNAs in COM. The expressions of miRNAs were further confirmed by quantitative real-time PCR (qPCR). Pathway analysis showed that deregulated miRNAs impact on cancer and signalling pathways. Three oncogenic miRNAs targets (miR-450b, 301a, and 223) from human study also were down-regulated in COM and had a significant negative correlation with their respective miRNA. Furthermore, we found that miR-450b expression is higher in metastatic cells and regulated MMP9 expression through a PAX9-BMP4-MMP9 axis. In silico analysis indicated that miR-126, miR-20b, and miR-106a regulated the highest numbers of differentially expressed transcription factors with respect to human melanoma. Chromosomal enrichment analysis revealed the X chromosome was enriched with oncogenic miRNAs. We comprehensively analyzed the miRNA's profile in COM which will be a useful resource for developing therapeutic interventions in both species. [ABSTRACT FROM AUTHOR]

• We identified miRNAs in canine mammary gland tumors using next generation sequencing with clinical samples. • Cfa-miR-1-3p and cfa-miR-133 family were downregulated in mammary gland tumor tissue (across histological subtypes). • GO and KEGG enrichment suggested cfa-miR-1/cfa-miR-133 family regulation of RNA polymerase II core promoter transcription. Canine mammary gland tumors are very common and represent a potential model of human breast cancer, and microRNA (miRNAs) are promising biomarkers and therapeutic targets for these tumors. Accordingly, we aimed to identify miRNAs differentially expressed in canine mammary gland tumors using next generation sequencing (NGS), with subsequent confirmatory qPCR and target gene analyses. Mammary gland tissue was collected from healthy dogs (n=7) and dogs with suspected tumors (n=80). A subset of samples was analyzed with NGS to identify differentially expressed miRNAs with CLC Genome Workbench. Normal (n=10), tumor-adjacent (n=6), and tumor-bearing (n=76) mammary gland tissue samples were analyzed for the identified miRNAs using qPCR. An in silico analysis (TargetScan) was performed to predict the miRNAs' target genes using gene ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database (DAVID). We identified four miRNAs (cfa-miR-1-3p, cfa-miR-133a-3p, cfa-miR-133b-3p, and cfa-miR-133c-3p) as down regulated in canine mammary gland tumor tissues relative to normal and tumor adjacent tissues. KEGG analysis revealed the potential target genes of cfa-miR-1-3p are related to the Rap1 signaling pathway, adherens junction, and Ras signaling pathway, and those of the miR-133 family are related to the TGF-beta signaling pathway, synaptic vesicle cycle, and sphingolipid signaling pathway. In combination, these target genes are related to the regulation of transcription and DNA binding transcription (GO analysis), and the Hippo signaling pathway, adherens junction, and endocytosis (KEGG analysis). Accordingly, we suggest these four miRNAs are promising potential biomarker candidates for canine mammary gland tumors warranting further investigation. [ABSTRACT FROM AUTHOR]

• Hypoxia regulated miRNAs (HRMs) in melanoma were identified. • Hypoxic response of HRMs are different between primary and metastatic melanoma cells. • MiR-21 and 301a lead hypoxic pathways in melanoma. MicroRNAs (miRNAs) can rapidly respond to cellular stresses, such as hypoxia. This immediate miRNA response regulates numerous genes and influences multiple signaling pathways. Therefore, identifying hypoxia-regulated miRNAs (HRMs) is important in canine oral melanoma (COM) to investigate their clinical significance. The hypoxic and normoxic miRNA profiles of two COM cell lines were investigated by next generation sequencing. HRMs were identified by comparing miRNA expression profiles in these cell lines with that in COM tissue. The HRM profile was different between cell lines of primary and metastatic origin, except for miR-301a and miR-8884. The time course of miRNA expression determined by qRT-PCR, especially for miR-210 and miR-301a, showed that metastatic cells are more resistant to hypoxia than primary cells. Analysis of an experimentally validated human miRNA target database revealed that miR-21 and miR-301a control a complex gene regulatory network in response to hypoxia, which includes pathways of well-known oncogenes, such as VEGF , PTEN , and TGFBR2. In conclusions, we revealed the HRM of COM. Moreover, our study shows the difference in regulation and response of hypoxic miRNAs between primary and metastatic originated melanoma cells. [ABSTRACT FROM AUTHOR]