Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2017

Erindi/veggspjald / Talk/poster V45

MiR-190b´s expression and methylation patterns in breast cancer.

Höfundar / Authors: Elísabet A Frick (1), Ólafur A Stefánsson (2), Þorkell Guðjónsson (2), Stefán Þ Sigurðsson (3)

Starfsvettvangur / Affiliations: Cancer Research Laboratory, BioMedical Center, University of Iceland

Kynnir / Presenter: Elísabet Alexandra Frick

Epigenetics and microRNAs (miRNA) are important supervisory mechanisms for maintaining gene expression patterns in the cell. Differential miRNA expression is commonly shown among breast cancer, often with tumor-suppressive or oncogenic roles. Data from The Cancer Genome Atlas indicate a potential association between altered expression of miR-190b and estrogen-receptor (ER) status in breast cancer. The aim of the first part of the study was to verify miR-190b‘s altered expression with regard to ER status in breast cancers and to understand if there were epigenetic mecanistics behind our findings. When processing our results we took clinical relevance into consideration, such as prognosis, tumor grading, staging along with other clinical markers. Our methods were based on the highly sensitive taqman advanced miRNA assay (RT-qPCR) and pyrosequencing methylation assay. We used a large cohort of well annotated breast cancers within the Icelandic population to define miR-190b‘s expression and methylation status across individual cancers. Our results indicate that miR-190b over-expression is the result of hypo-methylation at its predicted promoter in ER+ breast cancers, namely LumA and LumB. Our findings furthermore demonstrate poorer breast cancer-specific survival in relation to methylation status between the ER+ subtypes, indicating that miR-190b is presumably clinically relevant.