Melanoma activation of 3-o-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin to a potent irreversible inhibitor of dihydrofolate reductase.
Human melanoma is a significant clinical problem because it is resistant to treatment by most chemotherapeutic agents, including antifolates. It is therefore a desirable goal to develop a second generation of low-toxicity antifolate drugs to overcome acquired resistance to the prevention and treatment of this skin pathology. In our efforts to improve the stability and bioavailability of green tea polyphenols for cancer therapy, we synthesized a trimethoxy derivative of epicatechin-3-gallate, which showed high antiproliferative and proapoptotic activity against melanoma. This derivative, 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG), is a prodrug that is selectively activated by the specific melanocyte enzyme tyrosinase. Upon activation, TMECG generates a stable quinone methide product that strongly inhibits dihydrofolate reductase in an irreversible manner. The treatment of melanoma cells with TMECG also affected cellular folate transport and the gene expression of DHFR, which supported the antifolate nature of this compound. In addition, its pharmacological efficacy has been confirmed in a mouse melanoma model, in which tumor growth and metastasis were inhibited, significantly enhancing the mean survival of the treated groups. TMECG, therefore, shows a potential for clinical use in melanoma therapy.
Sánchez-del-Campo
Luís
L
Department of Biochemistry and Molecular Biology A, University of Murcia, Murcia, Spain.
Tárraga
Alberto
A
Montenegro
María F
MF
Cabezas-Herrera
Juan
J
Rodríguez-López
José Neptuno
JN
D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002392:Catechin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use; D049109:Cell Proliferation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006801:Humans; D008544:Melanocytes / Q000201:enzymology; D008545:Melanoma / Q000188:drug therapy* / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D014442:Monophenol Monooxygenase / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism*
C529447:3-O-(3,4,5-trimethoxybenzoyl)epicatechin; D000970:Antineoplastic Agents; D002392:Catechin; D014442:Monophenol Monooxygenase; D013762:Tetrahydrofolate Dehydrogenase