The Regulatory Mechanisms Of HOXB13 Gene

HOXB13 gene belongs to a large Homeobox gene superfamily.Expression of HOXB13 is restricted to the AR(androgen receptor)-expressing prostate cells.However,the mechanism underlying this silencing is not fully understood.As a polycomb group(PcG) protein,YY1 can either activate or repress gene transcription.Previous biochemical studies have revealed that YY1 plays an important role in the expression regulation of eukaryotic genes.In this report,we found that YY1 repressed the activities of the HOXB13 promoter by the relative luciferase activity assays in 293T cells.The results of RT-PCR and Western Blot confirmed YY1 regulate the HOXB13 gene expression in the levels of mRNA and protein. The chromatin immunoprecipitation(CHIP) assays verified that YY1 regulated the transcription of HOXB13 gene by binding to the promoter directly.Moreover,promoter truncation and point mutation studies determined that the two proximal binding sites for YY1 on the HOXB13 promoter were essential for the recruitments of YY1.Data presented in this report suggested that YY1 affected cell growth by repressing the expression of HOXB13.Overall,data from this study suggest that YY1 affected cell growth by repressing transcriptional regulation of HOXB13 through binding to the promoter.These data will contribute to elucidating the unique mechanisms of HOXB13 transcriptional regulation, which is crucial to the development of new therapeutic strategies for HOXB13-related gene therapy.