Src Inhibition Blocks c-Myc Translation and Glucose Metabolism to Prevent the Development of Breast Cancer.
Cancer Res 2015;
75:4863-75. [PMID:
26383165 DOI:
10.1158/0008-5472.can-14-2345]
[Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 07/31/2015] [Indexed: 11/16/2022]
Abstract
Preventing breast cancer will require the development of targeted strategies that can effectively block disease progression. Tamoxifen and aromatase inhibitors are effective in addressing estrogen receptor-positive (ER(+)) breast cancer development, but estrogen receptor-negative (ER(-)) breast cancer remains an unmet challenge due to gaps in pathobiologic understanding. In this study, we used reverse-phase protein array to identify activation of Src kinase as an early signaling alteration in premalignant breast lesions of women who did not respond to tamoxifen, a widely used ER antagonist for hormonal therapy of breast cancer. Src kinase blockade with the small-molecule inhibitor saracatinib prevented the disorganized three-dimensional growth of ER(-) mammary epithelial cells in vitro and delayed the development of premalignant lesions and tumors in vivo in mouse models developing HER2(+) and ER(-) mammary tumors, extending tumor-free and overall survival. Mechanistic investigations revealed that Src blockade reduced glucose metabolism as a result of an inhibition in ERK1/2-MNK1-eIF4E-mediated cap-dependent translation of c-Myc and transcription of the glucose transporter GLUT1, thereby limiting energy available for cell growth. Taken together, our results provide a sound rationale to target Src pathways in premalignant breast lesions to limit the development of breast cancers.
Collapse