SNX-2112 is a potent inhibitor of synthetic heat shock protein (Hsp 90) with IC50 value of 30 nM.[1]
HSP90 (heat shock proteins) is widely expressed as a molecular chaperone. It plays an important role in the folding and stabilization of cellular proteins. HSP90 protects client proteins from degradation and maintains them in an active conformation. Many clientsof HSP90 are transcription factors or protein kinases such as: Bcr-Abl, tyrosine kinas, EGFR family members, IGF1-R, c-Met, steroid hormone receptors, p53, Mdm2 and telomerase. In a variety of cancers, overexpressed hsp90 has been detected. Hsp90 also play an important role in maintaining the transformed phenotype of cancer cell. So, Hsp 90 is one attractive target for cancer therapy.
SNX-2112 is a potent inhibitor of Hsp 90 in different cancer cell lines. In the MTT assay, SNX-2112 inhibited A-375 cells with IC50 values of 1.25 μM at 48h. In the western blot assay, 0.2 M SNX-2112 significantly reduced several growth-related Hsp90 client proteins such as Akt, p-Akt, IKKα, B-Raf, Erk1/2, p-Erk1/1, GSK3β and Chk1 in a time-dependent manner after 24h treatment. In the DAPI staining and the TUNEL assay, conclusive double-stranded DNA fragmentation were produced after exposure to 0.2?μM SNX-2112.[2] Moreover, in the cell cycle assays, in 3 MET-amplified tumor cell lines (GTL-16, MKN-45 and EBC-1), 50nM SNX-2112 induced G1 arrest while in higher concentration such as 100 and 1000nM, more cells accumulated in G2 phase.[3] In pediatric cancer cell lines (SK-N-DZ, SK-N-AS, BE(2)-C, Saos-2, SK-N-SH, and U-2-OS ) SNX-2112 showed inhibition properties at IC50 values ranging from 20-40 nM.[4]
References:
1.Chandarlapaty S, et al.SNX2112, a synthetic heat shock protein 90 inhibitor, has potent antitumor activity against HER kinase-dependent cancers. Clin cancer Res(2008) 14(1): 240-248
2.Kai-Sheng Liu, et al. SNX-2112, an Hsp90 inhibitor, induces apoptosis and autophagy via degradation of Hsp90 client proteins in human melanoma A-375 cells. Cancer Letters. (2012) 318 180–188
3.Antitumor activity of SNX-2112, a synthetic heat shock protein-90 inhibitor, in MET-amplified tumor cells with or without resistance to selective MET inhibition. Clin Cancer Res. (2011) 17(1): 122–133
4.Daniel le C. Chin n,BS, et al. Anti-Tumor Activity of the HSP90 Inhibitor SNX-2112 in Pediatric Cancer Cell Lines. Pediatr Blood Cancer (2012)58:885–890
