title: PU.1-dependent regulation of UCH L1 expression in B-lymphoma cells.
abstract: Elevated levels of ubiquitin C-terminal hydrolase L1 (UCH L1) have been detected in a variety of malignancies, and recent studies show the oncogenic capacity of overexpressed UCH L1 in vivo in animal models. Here we demonstrate that expression of endogenous UCH L1 is significantly higher in B-lymphoma cells than in transformed cells of epithelial and fibroblastic origin. The specific hematopoietic transcription factor PU.1 induces UCH L1 expression through direct activation of the uch l1 promoter. Using chromatin immunoprecipitation (ChIP) assays and direct mutagenesis we identified PU.1 binding sites on the uch l1 promoter, at least three of which are involved in this activation. We also show that the viral transcriptional co-activator EBNA2 dramatically increases PU.1-dependent up-regulation of endogenous UCH L1 expression. Finally, inhibition of PU.1 expression with specific shRNA resulted in reduction of UCH L1 mRNA and protein levels in Epstein-Barr virus (EBV)-transformed B-cells. We propose that the ubiquitin-editing enzyme UCH L1 is a multifunctional pro-oncogenic factor involved in development and progression of certain lymphoid malignancies, including EBV-associated lymphomas.
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Anjali
authors.initials: A
authors.lastname: Bheda
authors.forename: Wei
authors.initials: W
authors.lastname: Yue
authors.forename: Anuradha
authors.initials: A
authors.lastname: Gullapalli
authors.forename: Julia
authors.initials: J
authors.lastname: Shackelford
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Pagano
mesh_terms: D001665:Binding Sites; D002051:Burkitt Lymphoma / Q000201:enzymology / Q000235:genetics; D045744:Cell Line, Tumor; D004720:Endonucleases; D015972:Gene Expression Regulation, Neoplastic; D004854:Herpesvirus 4, Human / Q000378:metabolism; D006801:Humans; D016393:Lymphoma, B-Cell / Q000201:enzymology* / Q000235:genetics*; D008954:Models, Biological; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D043222:Ubiquitin Thiolesterase / Q000235:genetics* / Q000378:metabolism*; D015854:Up-Regulation; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D004720:Endonucleases; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D043222:Ubiquitin Thiolesterase; D000099232:Proto-Oncogene Protein Spi-1; C482860:UCHL1 protein, human; C095221:SND1 protein, human