Procaine is a DNA-demethylating agent with growth-inhibitory effects in human cancer cells.
Methylation-associated silencing of tumor suppressor genes is recognized as being a molecular hallmark of human cancer. Unlike genetic alterations, changes in DNA methylation are potentially reversible. This possibility has attracted considerable attention from a therapeutics standpoint. Nucleoside-analogue inhibitors of DNA methyltransferases, such as 5-aza-2'-deoxycytidine, are able to demethylate DNA and restore silenced gene expression. Unfortunately, the clinical utility of these compounds has not yet been fully realized, mainly because of their side effects. A few non-nucleoside inhibitors of DNA methyltransferases have been reported, including the anti-arrhythmia drug procainamide. Following this need to find new demethylating agents, we have tested the potential use of procaine, an anesthetic drug related to procainamide. Using the MCF-7 breast cancer cell line, we have found that procaine is a DNA-demethylating agent that produces a 40% reduction in 5-methylcytosine DNA content as determined by high-performance capillary electrophoresis or total DNA enzyme digestion. Procaine can also demethylate densely hypermethylated CpG islands, such as those located in the promoter region of the RAR beta 2 gene, restoring gene expression of epigenetically silenced genes. This property may be explained by our finding that procaine binds to CpG-enriched DNA. Finally, procaine also has growth-inhibitory effects in these cancer cells, causing mitotic arrest. Thus, procaine is a promising candidate agent for future cancer therapies based on epigenetics.
Villar-Garea
Ana
A
Cancer Epigenetics Laboratory, Molecular Pathology Program, Spanish National Cancer Centre (CNIO), Madrid 28029, Spain.
Fraga
Mario F
MF
Espada
Jesus
J
Esteller
Manel
M
D000970:Antineoplastic Agents / Q000494:pharmacology*; D018899:CpG Islands; D004247:DNA / Q000378:metabolism; D019175:DNA Methylation; D004305:Dose-Response Relationship, Drug; D016147:Genes, Tumor Suppressor; D006801:Humans; D011343:Procaine / Q000378:metabolism / Q000494:pharmacology*; D018168:Receptors, Retinoic Acid / Q000235:genetics; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D018168:Receptors, Retinoic Acid; C082925:retinoic acid receptor beta; D011343:Procaine; D004247:DNA