Molecular cloning and characterization of a human PAX-7 cDNA expressed in normal and neoplastic myocytes

Abstract

The myogenic basic helix-loop-helix proteins are

Transcriptional modulation of the anti-apoptotic protein BCL-XL by the paired box transcription factors PAX3 and PAX3/FKHR

“…An oncogenic role of PAX3 is further supported by two additional observations: First, the oncogenic tyrosine kinase reporter c-met has been identi®ed as a common target gene for PAX3 and its fusion protein in myoblasts as well as RMS cells Ginsberg et al, 1998). Second, expression of either PAX3 and/or PAX7 is a common event in RMS (Frascella et al, 1998;SchaÈ fer et al, 1994) and possibly other tumors (FA Scholl, unpublished observation). The enhanced transforming potential observed with the PAX3/FKHR fusion protein might depend either on the aquisition of additional novel target gene speci®cities or enhanced activation of common targets such as the oncogenes cmet and bcl-xl.…”

“…RD cells, primary human lung MRC-5 ®broblasts, 10T1/2 mouse ®broblasts and Cos-1 cells were purchased from American Type Culture Collection (Rockville, MD, USA). Primary human myoblasts B6M and A33 were isolated as described (SchaÈ fer et al, 1994). The Phoenix amphotrophic packaging cell line was obtained from Dr Gary Nolan (Stanford University of Medicine, Stanford, CA, USA) and the C2C12 mouse muscle cell line from Dr Helen Blau (Stanford University of Medicine).…”

“…The complete coding region of the murine Pax3 cDNA (SchaÈ fer et al, 1994) and the complete coding sequence for the human PAX3/FKHR cDNA (Bennicelli et al, 1996) were cloned into the SnaBI restriction site of the retroviral vector pBabePuro (Morgenstern and Land, 1990) via blunt-end ligation or the EcoRI/XbaI (Pax3) or BamHI/XbaI (PAX3/ FKHR) restriction sites of the pcDNA3 vector. The complete coding sequence of the human BCL-XL was cloned into the EcoRI restriction site of pBabeBleo.…”

“…However, these factors are inactive in tumor cells and therefore not able to e ciently drive di erentiation (Tapscott et al, 1993). eRMS often presents with mutations in the p53 tumor suppressor gene, the ras oncogene and an aberrant expression of the transcription factors PAX3 and/or PAX7 (Frascella et al, 1998;SchaÈ fer, 1998). The more aggressive form of RMS, the alveolar subtype, is characterized by two speci®c translocations between chromosomes 2 and 13 (t(2;13) (q35;q14)) or 1 and 13 (t(1;13) (p36;q14), resulting in chimaeric genes encoding the fusion transcription factors PAX3/FKHR and PAX7/FKHR (Galili et al, 1993;Davis et al, 1994).…”

Gene fusions involving PAX and FOX family members in alveolar rhabdomyosarcoma

“…PAX5 targets can be divided into two sets of binding sites, the longer class I sites that require both N-terminal and C-terminal subdomains, and the shorter class II sites (which includes e5 and related sequences) that only require the N-terminal subdomain. A comparison of PAX3 and PAX5 DNA binding initially indicated that only PAX5 can bind class I sites whereas both PAX3 and PAX5 can bind class II sites (Schafer et al, 1994). However, subsequent studies identi®ed an alternative splice that removes a single glutamine residue in the paired box of PAX3 and increases the a nity for class I sites (Figure 3).…”