The Impact of miR-200s on HER2+ Breast Cancer

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University of Guelph


Human Epidermal Growth Factor Receptor 2 positive (HER2+) breast cancer is diagnosed in 20% of all breast cancer patients and patients with HER2+ breast cancer have poor prognoses. While this form of breast cancer is treatable, the survival rate has only slightly improved as resistance frequently occurs. The miR-200 family has been characterized by our lab previously to inhibit tumour initiation, reduce tumour growth, reduce metastasis and proliferation in triple negative breast cancer but the impact of miR-200s in HER2+ breast cancer remains largely unexplored. This study used two human HER2+ breast cancer cell lines and transgenic mice to investigate the impact of miR-200 overexpression on proliferation, apoptosis and migration in vitro and tumour growth in vivo. Overexpression of the miR-200ba429 cluster in HER2+ breast cancer led to significant reductions in proliferation and migration rate while also significantly increasing the rate of apoptosis in both cell lines. The in vivo overexpression of the miR-200ba429 cluster prevented tumor initiation induced by Neu (rodent version of HER2). Together, the in vitro and in vivo research shows that the miR-200 family negatively regulates tumor initiation, proliferation and migration of HER2+ breast cancer.



Breast Cancer, MicroRNAs, MiR-200 Family, HER2+ Breast Cancer