title: The histone deacetylase inhibitor butyrate downregulates cyclin B1 gene expression via a p21/WAF-1-dependent mechanism in human colon cancer cells.
abstract: Histone deacetylase (HDAC) inhibitors are showing promise as treatment for a variety of human cancers, but their precise mechanism of action has not been elucidated. We examined the effects of the HDAC inhibitor butyrate on colon cancer cells, focusing on its effect on the cell cycle promoter cyclin B(1). In HT-29 cells, sodium butyrate-mediated growth inhibition is associated with a marked decrease in cyclin B(1) mRNA levels. The decrease in cyclin B(1) occurred in a delayed fashion (at 24 h), is completely blocked by concomitant treatment with protein synthesis inhibitors, and appears to be dependent on changes in transcription. Cyclin B(1) repression is linked to the differentiation process in colon cancer cells, not merely with growth arrest. The mechanism of cyclin B(1) repression by butyrate requires prolonged histone hyperacetylation and is at least partly dependent on p21 expression. In fact, p21/WAF-1 appears to directly repress a minimal cyclin B(1) promoter (-90 bp), a process that can be mediated by the amino-terminal portion of the p21 protein. These findings highlight key molecular mechanisms by which HDAC inhibitors mediate their beneficial effects on human cancer cells.
authors.affiliation: Dept. of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Sonia Y
authors.initials: SY
authors.lastname: Archer
authors.forename: Jennifer
authors.initials: J
authors.lastname: Johnson
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Kim
authors.forename: Qing
authors.initials: Q
authors.lastname: Ma
authors.forename: Huizhong
authors.initials: H
authors.lastname: Mou
authors.forename: Vishnuvardhan
authors.initials: V
authors.lastname: Daesety
authors.forename: Shufen
authors.initials: S
authors.lastname: Meng
authors.forename: Richard A
authors.initials: RA
authors.lastname: Hodin
mesh_terms: D000107:Acetylation; D015152:Blotting, Northern; D015153:Blotting, Western; D002087:Butyrates / Q000494:pharmacology*; D018938:Caco-2 Cells; D018797:Cell Cycle Proteins / Q000235:genetics*; D002454:Cell Differentiation / Q000187:drug effects; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000235:genetics; D019926:Cyclin B / Q000235:genetics*; D056744:Cyclin B1; D050759:Cyclin-Dependent Kinase Inhibitor p21; D015536:Down-Regulation / Q000187:drug effects; D019073:HT29 Cells; D006207:Half-Life; D056572:Histone Deacetylase Inhibitors; D006801:Humans; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: D002087:Butyrates; C534699:CCNB1 protein, human; C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D019926:Cyclin B; D056744:Cyclin B1; D050759:Cyclin-Dependent Kinase Inhibitor p21; D056572:Histone Deacetylase Inhibitors; D012333:RNA, Messenger