Immortalization of mouse myogenic cells can occur without loss of p16INK4a, p19ARF, or p53 and is accelerated by inactivation of Bax.

Background: Upon serial passaging of mouse skeletal muscle cells, a small number of cells will spontaneously develop the ability to proliferate indefinitely while retaining the ability to differentiate into multinucleate myotubes. Possible gene changes that could underlie myogenic cell immortalization and their possible effects on myogenesis had not been examined.

Results: We found that immortalization occurred earlier and more frequently when the myogenic cells lacked the pro-apoptotic protein Bax.