p53 positively regulates transcription of MIR34 microRNAs

Transcription of microRNA MIR34A is directly induced by the tumor suppressor p53, which binds to the conserved p53 binding site located in the vicinity of the MIR34A transcription start (Chang et al. 2007, Raver-Shapira et al. 2007). Genomic loss of the chromosomal band 1p36, harboring the MIR34A gene, is a frequent event in pancreatic cancer, and MIR34A is considered to act as a tumor suppressor. Conserved p53 binding sites were also mapped to the promoter of clustered MIR34B and MIR34C genes, and the transcription of MIR34B and MIR34C microRNAs was shown to be positively regulated by p53 (He et al. 2007, Corney et al. 2007). The steps involved in processing of pri-microRNA into pre-microRNA have been omitted in this event - please refer to the diagram of Regulatory RNA Pathways for details.

转录因子MIR34A的转录直接受抑癌基因p53的诱导，p53与位于MIR34A转录起始点附近的保守p53结合位点相结合（Chang等，2007年，Raver-Shapira等，2007年）。携带MIR34A基因的染色体带1p36的基因组丢失在胰腺癌中是一种常见现象，MIR34A被认为具有抑癌作用。保守的p53结合位点还映射到成簇的MIR34B和MIR34C基因的启动子区域，研究表明，MIR34B和MIR34C微RNA的转录受到p53的正向调控（He等，2007年，Corney等，2007年）。在此过程中，将前体微RNA加工为前体微RNA的步骤已被省略，请参阅调控RNA通路图以获取详细信息。