The c-abl, bcr and C lambda genes are amplified in a cell line but not in the uncultured cells from a patient with chronic myelogenous leukemia.

Structural alterations of the oncogenes in human tumors are reported to result from a variety of mechanisms: point mutations, chromosomal translocations and gene amplifications. In over 90% of the cases of chronic myelogenous leukemia (CML), the c-abl oncogene is translocated from chromosome 9 to chromosome 22, and forms in part the Philadelphia (Ph1) chromosome. We have molecularly analysed a double Ph1-positive (Ph1+) cell line, KBM-5 that was established from a patient with CML in the blast-transformed phase (CML-BP). We report that the c-abl, bcr, and C lambda genes are amplified approximately eight-fold in the cell line but not in the fresh uncultured cells from which KBM-5 was derived.