Medline ® Abstract for Reference 63
Evidence for a multistep pathogenesis of chronic myelogenous leukemia.
Fialkow PJ, Martin PJ, Najfeld V, Penfold GK, Jacobson RJ, Hansen JA
To study the relationship of the Philadelphia chromosome (Ph1) to the pathogenesis of chronic myelogenous leukemia, multiple B-lymphoid cell lines were established from a patient with Ph1-positive leukemia who was heterozygous for the X-chromosome-linked enzyme glucose-6-phosphate dehydrogenase. Both A and B types of enzyme were found in a 1:1 proportion in normal tissues, but 45 of 63 (71%) Ph1-negative B-lymphoid cells lines derived from this patient showed only the single glucose-6-phosphate dehydrogenase (type B) found in the Ph1-positive leukemic clone. Furthermore, 8 of 33 analyzable lines with B-type enzyme had chromosomal aberrations compared to 0 of 14 lines with A-type glucose-6-phosphate dehydrogenase. These results provide evidence for the suggestion that some cells of the abnormal clone do not express the Ph1 abnormality. Thus, acquisition of Ph1 may not be a sufficient cause for the disease. It is possible that at least two steps are involved in the pathogenesis of Ph1-positive chronic myelogenous leukemia, one causing abnormal proliferation of a clone of pluripotent hematopoietic stem cells and the other inducing Ph1 in descendants of these progenitors.