title: Relapse cell population differs from acute onset clone as shown by absence of the initially activated N-ras oncogene in a patient with acute myelomonocytic leukemia.
abstract: We have conducted a follow-up study of a patient with myelomonocytic leukemia exhibiting an N-ras mutation (Gln61----Lys61) using the polymerase chain reaction method and synthetic oligonucleotide hybridization probes. This method allowed us to detect as little as 3% of N-ras-mutated cells within a population. When the patient went into clinical remission, the mutation became undetectable. When a relapse occurred, the blasts did not carry the N-ras mutation. Analysis of M13 cloned amplified N-ras sequences from relapse DNA revealed exclusively the wild type allele of the N-ras gene. These findings suggest that the relapse cell population is derived from a different clone than the acute phase population. Furthermore, the data argue that N-ras mutation is not an initiating lesion in this case of acute myelomonocytic leukemia (AMML).
mesh_terms: D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D003001:Cloning, Molecular; D005260:Female; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D011905:Genes, ras; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000473:pathology; D008875:Middle Aged; D009154:Mutation; D012008:Recurrence