PAX3-FOXO1 escapes miR-495 regulation during muscle differentiation

Abstract

Pax3 plays an essential role in myogenesis. Previously, we found a tumor-signature chimeric fusion RNA, PAX3-FOXO1 also present during muscle differentiation, raising the possibility of its physiological role. Here we demonstrated that the fusion is needed transiently for muscle lineage commitment. Interestingly, the fusion ortholog was not found in seven mouse muscle differentiation/regeneration systems, nor in other stem cell differentiation systems of another three mammal species. We noticed that Pax3 is expressed at a much lower level in human stem cells, and during muscle differentiation than in other mammals. Given the fact that the fusion and the parental Pax3 share common downstream targets, we reasoned that forming the fusion may be a mechanism for human cells to escape certain microRNA regulation on Pax3. By sequence comparison, we identified 16 candidate microRNAs that may specifically target the human PAX3 3ʹUTR. We used a luciferase reporter assay, examined the microRNAs expression, and conducted mutagenesis on the reporters, as well as a CRISPR/Cas9 mediated editing on the endogenous allele. Finally, we identified miR-495 as a microRNA that specifically targets human PAX3. Examining several other fusion RNAs revealed that the human-specificity is not limited to PAX3-FOXO1. Based on these observations, we conclude that PAX3-FOXO1 fusion RNA is absent in mouse, or other mammals we tested, the fusion RNA is a mechanism to escape microRNA, miR-495 regulation in humans, and that it is not the only human-specific fusion RNA.

MiR‐543 regulates myoblast proliferation and differentiation of C2C12 cells by targeting KLF6

“…miR‐543 belongs to the miR379‐410 cluster, which is on the chromosome 12 of the house mouse and contains a large cluster of noncoding RNAs including miR‐543, miR‐329, miR‐369‐3p, miR‐495, and miR‐496 27 . Most of these miRNAs participate in muscle differentiation or muscle‐related diseases 28,29 . Thus, we speculated that miR‐543 may also participate in myogenesis.…”

“…27 Most of these miRNAs participate in muscle differentiation or muscle-related diseases. 28,29 Thus, we speculated that miR-543 may also participate in myogenesis.…”

NLRP3 Inflammasome Activation by MicroRNA-495 Promoter Methylation May Contribute to the Progression of Acute Lung Injury

“…The synthesized cDNA was detected using Fast SYBR Green PCR Kits (Applied Biosystems, Carlsbad, CA, USA). The primers for qRT-PCR were synthesized by Sangon Biotech (Shanghai, China), and the sequences were as follows: reverse primer: 5′-GAGACTGCGGATGTATAGAACTTGA-3′; forward primer: 5′-AAACAAACATGGTGCACTTCTT-3′ 45 …”

Soft Tissue Sarcoma: An Insight on Biomarkers at Molecular, Metabolic and Cellular Level

“…Furthermore, a cytogenic analysis of STSs identified chromosomal translocations that induced the encoding of specific tumor subtype oncoproteins: Ewing’s sarcoma (EWS–FLI-1 fusion), clear cell sarcoma (EWS–ATF1 fusion), myxoid sarcoma (TLS–CHOP fusion), alveolar rhabdomyosarcoma (PAX3–FHKR fusion), and small round cell desmoplastic tumor (EWS–WT1 fusion) [ 83 , 84 , 85 , 86 , 87 ]. In a study carried out with next-generation sequencing on 25 cases of STS, Myc amplification was observed in 33% of the cases, MAP2K4 in 20%, and CNV and FGFR amplification in 40% of the studied cases.…”