3408
Since it is known that PGE2 is able to increase cAMP levels , we investigated whether it can affect gene expression through the activation of the transcription factors which bind enhancer elements in the promoter regions of cAMP -regulated genes .
 ( protein: transcription factors, None) , ( DNA: cAMP -regulated genes, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( protein: transcription factors, None) , ( DNA: cAMP -regulated genes, None) 