c-Myc-deficient B lymphocytes are resistant to spontaneous and induced cell death.

C-myc gene is a member of the myc family of proto-oncogenes involved in proliferation, differentiation, and apoptosis. Overexpression of c-myc in fibroblasts causes apoptosis under low serum conditions in a process that requires the interaction of CD95 and CD95L on the surface. We have previously reported an in vivo conditional model to inactivate the c-myc gene in B lymphocytes. Here, we show that c-Myc-deficient primary B lymphocytes are resistant to different apoptotic stimuli. Nonactivated c-Myc-deficient B cells are resistant to spontaneous cell death. Upon activation, c-Myc-deficient B lymphocytes express normal surface levels of activation markers, and show resistance to staurosporine and CD95-induced cell death.