Thirteen miRNAs involved in the response of breast cancer cells to doxorubicin

• Published in: Journal of clinical oncology Vol. 31; no. 15_suppl; p. e12019
• Main Authors: Tormo, Eduardo, Pineda, Begoña, Ballester, Sandra, Burgues, Octavio, Serna, Eva, Lluch, Ana, Eroles, Pilar
• Format: Journal Article
• Language: English
• Published: 20.05.2013
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2013.31.15_suppl.e12019

Abstract only e12019 Background: Mature microRNAs (miRNAs) are a class of naturally occurring, small non-coding RNA molecules, about 21–25 nucleotides. Growing evidence shows that miRNAs exhibit a variety of regulatory functions related to cell growth, development, and differentiation, and are associated with a wide variety of human diseases. Several miRNAs have been linked to cancer; since expression analysis studies have revealed perturbed miRNA expression in tumors compared to normal tissues. As a consequence, human miRNAs are likely to be highly useful as biomarkers, especially for future cancer diagnostics, and are emerging as targets for disease intervention. Since doxorubicin (DOX) has been used for a long time in breast cancer treatment, and resistance mechanisms are not clear understood, the aim of this work was to find a miRNA expression profile that could explain the regulation in different breast cancer cell lines under DOX treatment. Methods: Three breast cancer cell lines (MDA-MB-231, MDA-MB-468, and MCF-7) were cultured in normal conditions and also treated with DOX. Total RNA containing small non-coding RNA was isolated and its expression profile was performed by using GeneChip miRNA 2.0 array. Real time PCR validation was carried out to confirm the results. Results: Principal Component Analysis (PCA) of the small non-coding RNA profiles showed different expression patterns between normal conditions and DOX treatment in each cell line separately. Taken together in a Heat Map, miRNA expression profiles of MDA-MB-231 and MDA-MB-468 cell lines were closer in both normal and DOX treatment conditions, while miRNA expression profile of MCF-7 cell line showed strong differences. Total of 13 common miRNAs between the three cell lines were found to be significantly affected by DOX treatment. PCR validation confirmed the results obtained. Conclusions: We conclude that 13 common miRNAs are responsables of changes compared to treatment with DOX in breast cancer cell lines MDA-MB-231, MDA-MB-468 and MCF-7. This miRNAs are mainly related with cellular processes such as cell differentiation, vascularisation, apoptosis and cell proliferation and also involved in other cellular processes, such as cell migration.