Platelet-derived growth factors α and β are differentially expressed in the primary tumors of breast cancer patients treated with trastuzumab.
Trastuzumab, a monoclonal antibody targeted against the human epidermal growth factor receptor 2 (HER2) is utilized for the treatment of human breast cancer (1, 2), but a complete understanding of how tumor signal transduction is modulated by trastuzumab treatment is lacking. By mining published and public microarray and gene expression data (3, 4) from the primary tumors of patients treated with trastuzumab, we found that platelet-derived growth factors α and β , PDGF-α and PDGF-β, are among the genes most differentially expressed in the primary tumors of patients treated with trastuzumab, and expressed at significantly higher levels in the tumors of patients treated with trastuzumab. Thus, the use of trastuzumab in patients with breast cancer is associated with increased expression growth factors important for development of the neural crest and neural tube (5,6).