Protein profiling of stress-activated breast cancer cell models

This study provides insights into the efficacy of beta-blockers as breast cancer therapeutics.Cell line models of basal-type and estrogen receptor-positive breast cancer were profiled for basal levels of adrenoceptor gene/protein expression, and ADRβ2-mediated cell behaviour including migration, invasion, adhesion, and proliferation in response to adrenoceptor agonist/antagonist treatment. Protein profiling and histology identified response biomarkers and drug targets. Protein profiling revealed the upregulation of the pro-metastatic gene LYPD3 in norepinephrine treated MDA MB 468 cells. Histology confirmed selective LYPD3 expression in clinical primary and metastatic breast tumours. These findings demonstrate that basal-type cancer models show a more aggressive ADRβ2-activated phenotype in the resting and stimulated state, which is attenuated by ADRβ2 inhibition, and explain some of the previous studies that have cast doubt on the value of beta-blocker therapy in breast cancer. These findings suggest that propranolol should be clinically evaluated in patients with basal-type tumours expressing high levels of ADRβ2 and LYPD3.