Loss of Amplified c-myc Genes in the Spontaneously Differentiated HL-60 Cells

摘要: Amplification of the c- myc gene in human promyelocytic leukemia cell line HL-60 is considered to be one major causes its malignant phenotype. It also well known since establishment that a culture cells contains small but fixed percentage spontaneously differentiated cells. We show spontaneous differentiation could result extensive losses amplified genes by findings: ( ) express Mac-1 (CR3, CD11b/CD18) antigen, irreversibly stop uptake [3H]thymidine, and die apoptosis; b these cells, when isolated, copy number precisely quantitated, genes; c low concentrations hydroxyurea increase which further decreased. A simple theoretical consideration suggests an active elimination process(es) must operating besides stochastic extrachromosomally unequal partition at mitosis.