The discovery and development of a novel HER-2 tyrosine kinase inhibitor for the treatment of HER2-positive breast cancer are presented in this article. EGFR family has been recognized as a crucial meditator in the cancer progression; HER-2 tyrosine kinase was one of the members among them. In the effort to explore potent HER-2 inhibitors, a novel series of 4-anilino-3-cyanoquinoline derivatives have been designed, synthesized and evaluated. Most compounds possessed modest proliferation inhibition on SK-BR-3 cell line and HER-2 kinase. Compound 16 appeared to be the most potent compound (HER-2 kinase IC 50 : 19.4 nM, SK-BR-3 IC 50 : 94 nM). In the experiment of cellular cytotoxicity assay, compound 16 shows a much lower cytotoxicity than neratinib on Beas-2b cell line (Human bronchial epithelial cells). In conclusion, compound 16 would be a promising lead compound for further anti-breast cancer drug discovery.
Liu Zundong,Sang Xiaolin,Wang Min,Liu Yichao,Liu Jiao,Wang Xuefei,Liu Pixu,Cheng Hailing
Complete blockade of the HER2 protein itself and HER signaling network is critical to achieving effective HER2-targeted therapies. Despite the success of HER2-targeted therapies, the diseases will relapse in a significant fraction of patients with HER2 + breast cancers. How to improve the therapeutic efficacy of existing HER2-targeted agents remains an unmet clinical need. Here, we uncover a role of Melatonin in diminishing HER2-mediated signaling by destruction of HER2 protein. Mechanistically, Melatonin treatment attenuated the protective effect of the HSP90 chaperone complex on its client protein HER2, triggering ubiquitylation and subsequent endocytic lysosomal degradation of HER2. The inhibitory effect of Melatonin on HER2 signaling substantially enhanced the cytotoxic effects of the pan-HER inhibitor Neratinib in HER2 + breast cancer cells. Lastly, we demonstrate that dual inhibition of HER2 by combined use of Melatonin and Neratinib effectively blocked the growth of HER2 + breast tumor xenografts in vivo. Our findings shed light on the potential use of Melatonin in a novel dual HER2 blockade strategy for HER2 + breast cancer treatment.