title: Establishment of clonal myogenic cell lines from severely affected dystrophic muscles - CDK4 maintains the myogenic population.
abstract: BACKGROUND
  A hallmark of muscular dystrophies is the replacement of muscle by connective tissue. Muscle biopsies from patients severely affected with facioscapulohumeral muscular dystrophy (FSHD) may contain few myogenic cells. Because the chromosomal contraction at 4q35 linked to FSHD is thought to cause a defect within myogenic cells, it is important to study this particular cell type, rather than the fibroblasts and adipocytes of the endomysial fibrosis, to understand the mechanism leading to myopathy.
  
  
  RESULTS
  We present a protocol to establish clonal myogenic cell lines from even severely dystrophic muscle that has been replaced mostly by fat, using overexpression of CDK4 and the catalytic component of telomerase (human telomerase reverse transcriptase; hTERT), and a subsequent cloning step. hTERT is necessary to compensate for telomere loss during in vitro cultivation, while CDK4 prevents a telomere-independent growth arrest affecting CD56+ myogenic cells, but not their CD56- counterpart, in vitro.
  
  
  CONCLUSIONS
  These immortal cell lines are valuable tools to reproducibly study the effect of the FSHD mutation within myoblasts isolated from muscles that have been severely affected by the disease, without the confounding influence of variable amounts of contaminating connective-tissue cells.
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center at Dallas, Dallas, TX, USA.
authors.forename: Guido
authors.initials: G
authors.lastname: Stadler
authors.forename: Jennifer Cj
authors.initials: JC
authors.lastname: Chen
authors.forename: Kathryn
authors.initials: K
authors.lastname: Wagner
authors.forename: Jerome D
authors.initials: JD
authors.lastname: Robin
authors.forename: Jerry W
authors.initials: JW
authors.lastname: Shay
authors.forename: Charles P
authors.initials: CP
authors.lastname: Emerson
authors.forename: Woodring E
authors.initials: WE
authors.lastname: Wright