Researchers have used antisense technology in test tubeexperiments to suppress the proliferation of a type ofleukemia while leaving the growth and development of normalmarrow cells intact.

The most common genetic abnormality in human leukemias is achange in chromosomes in the immature bone marrow cellsthat become myeloid white blood cells. A piece of chromosome9 moves to a region in chromosome 22.

Researchers at Temple University medical school and theUniversity of Pennsylvania, both in Philadelphia, made anantisense strand of genetic material that is complementary tothis translocated gene. The antisense DNA sequence suppressedthe protein synthesis directed by the mutated gene, thescientists reported today in Science.

Placed in culture with leukemia cells taken from patients withchronic myelogenous leukemia, the antisense nucleotides alsosuppressed the growth of leukemia cell colonies. When mixedwith equal parts of leukemic and normal cells, the majority ofcells surviving in the presence of the antisense moleculeshowed normal, non-cancerous characteristics.

Not all leukemic cells turned out to be sensitive to theantisense attack, perhaps because some of the cells hadadditional chromosomal mutations that the antisense strandwas not designed to recognize.

Nevertheless, the researchers concluded, the resultsdemonstrate that gene-targeted, selective killing of cancercells is feasible using antisense technology. They anticipatethat antisense molecules could be tailor-made to recognizeand neutralize the mutations of patients' leukemic cells,within a few days of diagnosis.

-- Roberta Friedman, Ph.D. Special to BioWorld

(c) 1997 American Health Consultants. All rights reserved.