Characterization, chemical optimization and anti-tumour activity of a tubulin poison identified by a p53-based phenotypic screen.
A robust p53 cell-based assay that exploits p53's function as a transcription factor was used to screen a small molecule library and identify bioactive small molecules with potential antitumor activity. Unexpectedly, the majority of the highest ranking hit compounds from this screen arrest cells in mitosis and most of them impair polymerization of tubulin in cells and in vitro. One of these novel compounds, JJ78:1, was subjected to structure-activity relationship studies and optimized leading to the identification of JJ78:12. This molecule is significantly more potent than the original hit JJ78:1, as it is active in cells at two-digit nanomolar concentrations and shows clear antitumor activity in a mouse xenograft model as a single agent. The effects of nocodazole, a well established tubulin poison, and JJ78:12 on p53 levels are remarkably similar, supporting that tubulin depolymerization is the main mechanism by which JJ78:12 treatment leads to p53 activation in cells. In summary, these results identify JJ78:12 as a potential cancer therapeutic, demonstrate that screening for activators of p53 in a cell-based assay is an effective way to identify inhibitors of mitosis progression and highlights p53's sensitivity to alterations during mitosis.
Staples
Oliver D
OD
Department of Surgery and Molecular Oncology, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland, UK.
Hollick
Jonathan J
JJ
Campbell
Johanna
J
Higgins
Maureen
M
McCarthy
Anna R
AR
Appleyard
Virginia
V
Murray
Karen E
KE
Baker
Lee
L
Thompson
Alastair
A
Ronseaux
Sebastien
S
Slawin
Alexandra M Z
AM
Lane
David P
DP
Westwood
Nicholas J
NJ
Lain
Sonia
S
D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D051379:Mice; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects; D008940:Mitotic Index; D010641:Phenotype; D015203:Reproducibility of Results; D013329:Structure-Activity Relationship; D014404:Tubulin / Q000378:metabolism; D050257:Tubulin Modulators / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D000970:Antineoplastic Agents; D014404:Tubulin; D050257:Tubulin Modulators; D016159:Tumor Suppressor Protein p53