A small-molecule E2F inhibitor blocks growth in a melanoma culture model.
HLM006474 was identified using a computer-based virtual screen and the known crystal structure of the DNA-bound E2F4/DP2 heterodimer. Treatment of multiple cell lines with HLM006474 resulted in the loss of intracellular E2F4 DNA-binding activity as measured by electrophoretic mobility shift assay within hours. Overnight exposure to HLM006474 resulted in down-regulation of total E2F4 protein as well as known E2F targets. The effects of HLM006474 treatment on different cell lines varied but included a reduction in cell proliferation and an increase in apoptosis. HLM006474 induced apoptosis in a manner distinct from cisplatin and doxorubicin. E2F4-null mouse embryonic fibroblasts were less sensitive than wild-type counterparts to the apoptosis-inducing activity of the compound, revealing its biological specificity. A375 cells were extremely sensitive to the apoptosis-inducing activity of the compound in two-dimensional culture, and HLM006474 was a potent inhibitor of melanocytes proliferation and subsequent invasion in a three-dimensional tissue culture model system. Together, these results suggest that interference with E2F activity using small molecules may have clinical application in cancer therapy.
Ma
Yihong
Y
Molecular Oncology Program, H Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, USA.
Kurtyka
Courtney A
CA
Boyapalle
Sandhya
S
Sung
Shen-Shu
SS
Lawrence
Harshani
H
Guida
Wayne
W
Cress
W Douglas
WD
D000631:Aminopyridines / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis; D002453:Cell Cycle; D045744:Cell Line, Tumor; D050684:E2F Transcription Factors / Q000037:antagonists & inhibitors*; D006912:Hydroxyquinolines / Q000494:pharmacology; D008546:Melanoma, Experimental / Q000473:pathology*; D051379:Mice
D000631:Aminopyridines; D000970:Antineoplastic Agents; D050684:E2F Transcription Factors; C000594637:HLM006474; D006912:Hydroxyquinolines