Presence of P210bcrabl is associated with decreased expression of a beta chemokine C10 gene in a P210bcrabl-positive myeloid leukemia cell line.

BACKGROUND Chronic myelogenous leukemia (CML) is thought to start with the acquisition of the t(9;22) chromosomal translocation that codes for the P210bcrabl tyrosine-specific protein kinase. The CML cells exhibit anchorage-independent cell growth and genetic instability. After the initial phase, the cells acquire the phenotype of growth factor-independent growth. After the chronic phase, the disease evolves into the accelerated and blastic phases through the process of sequential random mutation. MATERIALS AND METHODS To identify some of the genetic changes that contribute to the phenotype of blastic and accelerated phase cells, we used differential display PCR to compare levels of cDNA reverse transcripts of mRNA in 32Dc13 cells and 32Dc13 cells that were stably transfected with a bcrabl cDNA plasmid in a constitutively expressed transcription unit. These cells were designated 32Dc13P210bcrabl. For these studies, we used the 32D myeloid leukemia cell line, which depends on IL-3 for growth. RESULTS Following introduction of the bcr-abl cDNA through transfection, the cell line became growth factor independent, mimicking the change in phenotype that occurs during the later phases of CML. These differential display screening assays detected altered levels of transcripts for 28 genes. Of interest to the biology of growth factor-independent growth in the bcrabl-positive 32D cells was the fact that the C10 beta chemokine gene was expressed at higher levels in the 32Dc13 cells than in the 32Dc13P210bcrabl cells. CONCLUSIONS These studies show that a C10 beta chemokine gene was expressed at different levels with or without P210bcrabl.