Medicine and Health Sciences Commons^™

Mir-21 Plays A Dual Role In Tumor Formation And Cytotoxic Response In Breast Tumors, Tu Dan, Anuradha A. Shastri, Ajay Palagani, Simone Buraschi, Thomas Neill, Jason E Savage, Aastha Kapoor, Tiziana Deangelis, Sankar Addya, Kevin Camphausen, Renato V. Iozzo, Nicole L Simone

Department of Radiation Oncology Faculty Papers

Breast cancer (BrCa) relies on specific microRNAs to drive disease progression. Oncogenic miR-21 is upregulated in many cancers, including BrCa, and is associated with poor survival and treatment resistance. We sought to determine the role of miR-21 in BrCa tumor initiation, progression and treatment response. In a triple-negative BrCa model, radiation exposure increased miR-21 in both primary tumor and metastases. In vitro, miR-21 knockdown decreased survival in all BrCa subtypes in the presence of radiation. The role of miR-21 in BrCa initiation was evaluated by implanting wild-type miR-21 BrCa cells into genetically engineered mouse models where miR-21 was intact, heterozygous …