Summary TP53 is the most frequently mutated gene in human cancer, and small-molecule reactivation of mutant p53 function represents an important anticancer strategy. A cell-based, high-throughput small-molecule screen identified chetomin (CTM) as a mutant p53 R175H reactivator. CTM enabled p53 to transactivate target genes, restored MDM2 negative regulation, and selectively inhibited the growth of cancer cells harboring mutant p53 R175H in vitro and in vivo. We found that CTM binds to Hsp40 and increases the binding capacity of Hsp40 to the p53 R175H mutant protein, causing a potential conformational change to a wild-type-like p53. Thus, CTM acts as a specific reactivator of the p53 R175H mutant form through Hsp40. These results provide new insights into the mechanism of reactivation of this specific p53 mutant.
Bibliographical noteFunding Information:
We thank Z. Yuan for MEF cells, X. Chen and J. Manfredi for mutant p53 plasmids and tet-inducible cell lines, J. Manfredi for p53 binding site of PUMA promoter plasmid, M. Taipale and S. Lindquist for materials and help on some heat-shock protein activity experiments, H. Li and S.J. Lee for help on Biacore studies, and W. Gu for in vitro gel-shift experiments. M.H. and T.N. were supported by postdoctoral fellowships for research abroad from the Japan Society for the Promotion of Science. M.H. was also supported by a research fellowship for research abroad from the Uehara Memorial Foundation. T.R.R. was supported by an F32 postdoctoral fellowship from the NIH (GM108415). The research was supported by NIH grants CA142805, CA149477, CA80058, and GM086258. Quantum-chemical calculations were run on the Odyssey cluster supported by the FAS Division of Science, Research Computing group at Harvard University.
All Science Journal Classification (ASJC) codes
- Molecular Medicine
- Molecular Biology
- Drug Discovery
- Clinical Biochemistry