Pax-5 Protein Expression Is Regulated by Transcriptional 3′UTR Editing

Autor: Annie-Pier Beauregard, Brandon Hannay, Ehsan Gharib, Nicolas Crapoulet, Nicholas Finn, Roxann Guerrette, Amélie Ouellet, Gilles A. Robichaud
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Cells, Vol 11, Iss 1, p 76 (2021)
Druh dokumentu: article
ISSN: 2073-4409
DOI: 10.3390/cells11010076
Popis: The Pax-5 gene encodes a transcription factor that is essential for B-cell commitment and maturation. However, Pax-5 deregulation is associated with various cancer lesions, notably hematopoietic cancers. Mechanistically, studies have characterized genetic alterations within the Pax-5 locus that result in either dominant oncogenic function or haploinsufficiency-inducing mutations leading to oncogenesis. Apart from these mutations, some examples of aberrant Pax-5 expression cannot be associated with genetic alterations. In the present study, we set out to elucidate potential alterations in post-transcriptional regulation of Pax-5 expression and establish that Pax-5 transcript editing represents an important means to aberrant expression. Upon the profiling of Pax-5 mRNA in leukemic cells, we found that the 3′end of the Pax-5 transcript is submitted to alternative polyadenylation (APA) and alternative splicing events. Using rapid amplification of cDNA ends (3′RACE) from polysomal fractions, we found that Pax-5 3′ untranslated region (UTR) shortening correlates with increased ribosomal occupancy for translation. These observations were also validated using reporter gene assays with truncated 3′UTR regions cloned downstream of a luciferase gene. We also showed that Pax-5 3′UTR editing has direct repercussions on regulatory elements such as miRNAs, which in turn impact Pax-5 protein expression. More importantly, we found that advanced staging of various hematopoietic cancer lesions relates to shorter Pax-5 3′UTRs. Altogether, our findings identify novel molecular mechanisms that account for aberrant expression and function of the Pax-5 oncogene in cancer cells. These findings also present new avenues for strategic intervention in Pax-5-mediated cancers.
Databáze: Directory of Open Access Journals
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