Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2019

Erindi/veggspjald / Talk/poster V31

The targets of miR-190b in breast cancer

Höfundar / Authors: Elísabet A Frick, Þorkell Guðjónsson, Stefán Siguðrsson

Starfsvettvangur / Affiliations: Háskóli Íslands

Kynnir / Presenter: Elísabet Alexandra Frick

Breast cancer, a complex and heterogeneous disease, is clinically categorized into five subtypes. These subtypes emerge by distinct tumor evolutionary paths and lead to diverse clinical outcome and prognosis. Estrogen receptor-positive (ER+) breast tumors are the most common form of breast cancer, representing approximately 70% of total cases. These cancers are further subdivided into subtypes LuminalA (LumA) and LuminalB (LumB). Inhibitors, targeting the estrogen receptor itself or the formation of estrogen, are the most common forms of treatment for Lum subtypes. These cancers have a relatively good prognosis, though a subset of patients responds poorly to treatments. This applies to LumB breast cancers in particular, which have higher proliferation rates and are diagnosed younger, leading to a worse prognosis. Previous research on the microRNA miR-190b has shown that it is up-regulated in ER+ breast cancers. Our recently published research suggests that miR-190b up-regulation occurs via loss of promoter DNA methylation. We furthermore have shown that miR-190b hypo-methylation leads to increased breast cancer-specific survival within patients diagnosed with LumA breast cancer, while an opposite trend can be seen in LumB patients. Our current research focus is to identify miR-190b’s target transcripts to follow up on and explain in more detail the biological significance of our findings. We aim to use CRISPR-Cas9 assisted knockout of miR-190b, followed by RNA-sequencing for target exploration. Additional methods include sequencing the product of target mRNA pulldown via biotin-labelled miRNA mimic.