REST is up-regulated by epidermal growth factor in HeLa cells and inhibits apoptosis by influencing histone H3 acetylation.
REST (repressor element 1-silencing transcription factor) is a transcription factor that recruits histone deacetylases to silence gene transcription. REST appears to play a paradoxical role in cancer cells: it exhibits tumor suppressor activity or promotes tumorigenesis, depending upon the setting. The extracellular signaling molecules that control REST gene expression in cancer cells remain poorly understood. In this study, we report that REST expression in HeLa cells is elevated in cells exposed to epidermal growth factor or serum, whereas the rate of cell apoptosis is low. Apoptosis induced by serum withdrawal is significantly increased in HeLa cells treated with an antisense phosphorothioate oligodeoxynucleotide (AS ODN) capable of down-regulating REST expression, whereas in HeLa cells transfected with a REST expressing plasmid, REST overexpression reduces the marked apoptosis caused, in absence of serum, by exposure to an anti-Fas receptor antibody imitating the Fas ligand activity plus PD 98059, a blocker of extracellular signal-regulated kinase 1/2 activation. REST knockdown also reduces mRNA levels of the antiapoptotic protein Bcl-X(L) whereas in HeLa cells overexpressing REST, the reduction of Bcl-X(L) mRNA caused by the anti-Fas receptor antibody plus PD 98059 is significantly decreased. Finally, we report that acetylation of histone H3 is increased in HeLa cells exposed to AS ODN or anti-Fas receptor antibody, whereas it is reduced in cells transfected with the REST expressing plasmid. Our findings indicate that REST is a novel gene regulated by EGF in HeLa cells that potentially contributes to the modulation of apoptosis via epigenetic mechanisms.
Department of Pharmacology, University of Bologna, Bologna, Italy.
Monica
M
Baiula
Gioia
G
Carbonari
Samantha D
SD
Dattoli
Maria
M
Calienni
Andrea
A
Bedini
Santi
S
Spampinato
D000107:Acetylation; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival; D003470:Culture Media; D016895:Culture Media, Serum-Free; D004815:Epidermal Growth Factor / Q000502:physiology*; D044127:Epigenesis, Genetic; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism*; D006801:Humans; D016376:Oligonucleotides, Antisense / Q000235:genetics; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation; D051020:bcl-X Protein / Q000235:genetics / Q000378:metabolism; D000099229:RE1-Silencing Transcription Factor
D053148:Caspase 3; D053179:Caspase 7; D003470:Culture Media; D016895:Culture Media, Serum-Free; D004815:Epidermal Growth Factor; D006657:Histones; D016376:Oligonucleotides, Antisense; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D012333:RNA, Messenger; D012097:Repressor Proteins; D051020:bcl-X Protein; D000099229:RE1-Silencing Transcription Factor; C494811:BCL2L1 protein, human; C499320:PARP1 protein, human; C505407:CASP3 protein, human; C505520:CASP7 protein, human