Predominant expression of alternative PAX3 and PAX7 forms in myogenic and neural tumor cell lines

Cancer Res. 1999 Nov 1;59(21):5443-8.


PAX3 and PAX7 are closely related paired box family members expressed during early neural and myogenic development. Assay of PAX3 and PAX7 mRNA expression in embryonal rhabdomyosarcoma, neuroblastoma, Ewing's sarcoma, and melanoma cell lines revealed tumor-specific expression patterns similar to the corresponding embryonic lineages. Although the mammalian PAX3 and PAX7 genes were reported to contain eight exons, we found that the predominant PAX3 and PAX7 transcripts in these tumor lines contain previously uncharacterized ninth exons. These splicing events alter the COOH-terminal coding regions of the encoded products but do not alter the transcriptional activity as assayed using a reporter gene with a model PAX3/PAX7 binding site. However, the findings of nearly identical COOH-terminal regions within the corresponding genes of the avian and fish genomes suggest conserved functional roles for these regions that require further investigation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • DNA-Binding Proteins / metabolism*
  • Exons
  • Gene Expression Regulation, Neoplastic*
  • Homeodomain Proteins*
  • Humans
  • Melanoma / metabolism*
  • Mice
  • Models, Genetic
  • Molecular Sequence Data
  • Muscle Proteins / metabolism*
  • Nerve Tissue Proteins / metabolism*
  • Neuroblastoma / metabolism*
  • PAX3 Transcription Factor
  • PAX7 Transcription Factor
  • Paired Box Transcription Factors
  • Plasmids / metabolism
  • RNA, Messenger / analysis
  • Rhabdomyosarcoma / metabolism*
  • Sarcoma, Ewing / metabolism*
  • Sequence Homology, Amino Acid
  • Transcription Factors*
  • Transcription, Genetic
  • Tumor Cells, Cultured


  • DNA-Binding Proteins
  • Homeodomain Proteins
  • Muscle Proteins
  • Nerve Tissue Proteins
  • PAX3 Transcription Factor
  • PAX3 protein, human
  • PAX7 Transcription Factor
  • PAX7 protein, human
  • Paired Box Transcription Factors
  • Pax7 protein, mouse
  • RNA, Messenger
  • Transcription Factors
  • Pax3 protein, mouse