INCREASED EXPRESSION OF A NOVEL C-ABL-RELATED RNA IN K562 CELLS

Abstract

The c-abl locus is translocated from chromosome 9 to chromosome 22 in chronic myelogenous leukemia (CML), creating the Philadelphia chromosome (22q-, Ph1), 1 of the most consistent chromosomal abnormalities found in human hematologic malignancy. The K562 cell line is a human cell line originally derived from a patient with CML. Cloned human c-abl probes were isolated to analyze the organization and expression of abl genes in patients with CML and in K562 cells. With these probes, the amplification of abl genes in K562 cells was confirmed. The presence of increased amounts of a novel RNA species hybridizing to a c-abl probe in K562 cells was demonstrated. This same large RNA species is present in addition to 2 normal transcripts in the leukemic cells of patients with CML. The c-abl locus apparently is abnormally expressed in CML.