miR-142-3p attenuates breast cancer stem cell characteristics and decreases radioresistance in vitro
Effectively targeting cancer stem cells, a subpopulation of tumorigenic, aggressive, and radioresistant cells, holds therapeutic promise. However, the effects of the microRNA miR-142-3p, a small endogenous regulator of gene expression on breast cancer stem cells, have not been investigated. This stu...
|Division/Institute:||FB 05: Medizinische Fakultät|
|Date of publication on miami:||16.05.2019|
|Edition statement:||[Electronic ed.]|
|Source:||Tumor Biology 40 (2018) 8, 1-10|
|Subjects:||Breast cancer; cancer stem cells; miR-142-3p; radiation; BRCA; mammospheres|
|DDC Subject:||610: Medizin und Gesundheit|
|License:||CC BY-NC 4.0|
|Funding:||Finanziert durch den Open-Access-Publikationsfonds 2018 der Deutschen Forschungsgemeinschaft (DFG) und der Westfälischen Wilhelms-Universität Münster (WWU Münster).|
|Other Identifiers:||DOI: 10.1177/1010428318791887|
Effectively targeting cancer stem cells, a subpopulation of tumorigenic, aggressive, and radioresistant cells, holds therapeutic promise. However, the effects of the microRNA miR-142-3p, a small endogenous regulator of gene expression on breast cancer stem cells, have not been investigated. This study identifies the influence of miR-142-3p on mammary stemness properties and breast cancer radioresistance to establish its role in this setting. miR-142-3p precursor transfection was performed in MDA-MB-468, HCC1806, and MCF-7 cells, and stem cell markers CD44, CD133, ALDH1 activity and mammosphere formation were measured. β-catenin, the canonical wnt signaling effector protein, was quantified by Western blots and cell fluorescence assays both in miR-142-3p–overexpressing and anti–miR-142-3p–treated cells. Radiation response was investigated by colony formation assays. Levels of BRCA1, BRCA2, and Bod1 in miR-142-3p–overexpressing cells as well as expression of miR-142-3p, Bod1, KLF4, and Oct4 in sorted CD44+/CD24–/low cells were determined by quantitative polymerase chain reaction. miR-142-3p overexpression resulted in a strong decline in breast cancer stem cell characteristics with a decrease in CD44, CD133, ALDH1, Bod1, BRCA2, and mammosphere formation as well as reduced survival after irradiation. miR-142-3p expression was strongly reduced in sorted CD44+/CD24–/low stem cells, while Bod1, Oct4, and KLF4 were overexpressed. β-catenin levels strongly decreased after miR-142-3p overexpression, but not after anti–miR-142-3p treatment. We conclude that miR-142-3p downregulates cancer stem cell characteristics and radioresistance in breast cancer, mediated by a reduced role of β-catenin in miR-142-3p–overexpressing cells. miR-142-3p might therefore help to target cancer stem cells.