The H19 TATA-less promoter is efficiently repressed by wild-type tumor suppressor gene product p53

摘要: The developmentally regulated H19 gene displays several remarkable properties: expression of an apparently non-translated mRNA, genomic imprinting (maternal allele only expressed), relaxation the and/or epigenetic lesions demonstrated in some tumors. Despite observations after status gene, data on trans and cis-acting factors required for human are still missing. As a first approach to address identification involved regulation we found that cells from p53 antisense-transfected HeLa clone displayed increased amounts transcripts when compared non-transfected cells. Moreover, stably transfected with temperature sensitive (ts) 143 Ala mutant exhibited temperature-dependent expression. This preliminary indication repressing effect protein has been confirmed by transient cotransfection experiments cells, using luciferase surrogate constructs under control 823 bp sequence immediately upstream transcription start point different containing sense, antisense or ts cDNA. We observed increase promoter-driven activity cotransfections cDNA at non-permissive temperature, but decrease sense wild-type Furthermore, were repeated cell line lacking endogenous p53. (Calu 6 cells) results provided additional evidence down protein.