4906
Our evidence derives from three principal observations : 1 ) a transfection construct containing only 122 nucleotides ( nt ) of promoter 1 and 328 nt of the 5 ' - UTR retained full PGE2 - stimulated reporter expression ; 2 ) maximal PGE2 - driven reporter expression required the presence of nt 196 to 328 of exon 1 when tested within the context of IGF - I promoter 1 ; 3 ) cotransfection of IGF - I promoter - luciferase - reporter constructs with a plasmid encoding the alpha - isoform of the catalytic subunit of murine cAMP - dependent protein kinase ( PKA ) produced results comparable to those seen with PGE2 treatment , whereas cotransfection with a plasmid encoding a mutant regulatory subunit of PKA that cannot bind cAMP blocked PGE2 - induced reporter expression .
 IGF - I promoter 1, IGF - I promoter, luciferase, murine cAMP - dependent protein kinase, PKA, PKA
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 IGF - I promoter 1, IGF - I promoter, luciferase, murine cAMP - dependent protein kinase, PKA, PKA