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Published on: June 7, 2016
Malignancy Associated MicroRNA Expression Changes in Canine Mammary Cancer of Different Malignancies
Marie-Charlotte von Deetzen1, Bernd T Schmeck2, Achim D Gruber1
1Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertag-Straße 15, 14163 Berlin, Germany.
Abstract:
MicroRNA has been suspected to be generally involved in carcinogenesis since their first description. A first study supported this assumption for canine mammary tumors when miRNA expression was compared to normal gland. The present study extends these results by comparing the expression of 16 microRNA (miRNA) and 4 small nucleolar RNA (snoRNA) in tumors of different malignancy, for example, adenomas, nonmetastasizing and metastasizing carcinomas as well as lymph node metastases, with each other and with normal mammary gland. All neoplastic tissues differed in their miR-210 expression levels from normal gland. While metastatic cells differed in their expression of mir-29b, miR-101, mir-125a, miR-143, and miR-145 from primary tumors, the comparison of miRNA expression in primary tumors of different malignancy failed to reveal significant differences except for a significant downregulation of mir-125a in metastasizing carcinomas when compared to adenomas.
Insights
MicroRNAs (miRNAs) are implicated in cancer. This study found specific miRNA expression differences in canine mammary tumors, distinguishing normal glands, primary tumors, and metastases.
Area of Science:
- Veterinary Oncology
- Molecular Biology
- Cancer Research
Background:
- MicroRNAs (miRNAs) are increasingly recognized for their role in carcinogenesis.
- Previous research indicated miRNA involvement in canine mammary tumors compared to normal glands.
- This study further investigates miRNA and small nucleolar RNA (snoRNA) expression across varying tumor malignancies.
Purpose of the Study:
- To compare miRNA and snoRNA expression profiles in canine mammary tumors of different malignancy grades.
- To identify specific miRNA and snoRNA signatures associated with tumor progression and metastasis.
- To establish a molecular basis for understanding canine mammary tumor development.
Main Methods:
- Quantitative analysis of 16 microRNAs (miRNAs) and 4 small nucleolar RNAs (snoRNAs).
- Comparison of RNA expression levels between normal mammary glands, adenomas, non-metastasizing carcinomas, metastasizing carcinomas, and lymph node metastases.
- Statistical analysis to identify significant differences in expression patterns.
Main Results:
- All neoplastic tissues exhibited distinct miR-210 expression compared to normal mammary glands.
- Metastatic cells showed altered expression of miR-29b, miR-101, miR-125a, miR-143, and miR-145 compared to primary tumors.
- A significant downregulation of miR-125a was observed in metastasizing carcinomas relative to adenomas, with other primary tumor comparisons showing no significant differences.
Conclusions:
- Specific microRNAs (miRNAs) are differentially expressed in canine mammary tumors, correlating with malignancy and metastatic potential.
- miR-210 is a potential biomarker for neoplastic mammary tissue in dogs.
- Distinct miRNA profiles in metastatic lesions suggest their role in the progression of canine mammary cancer.
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