PML/RAR-alpha rearrangement in acute promyelocytic leukaemias apparently lacking the t(15;17) translocation.
Recent investigations have clarified some of the molecular mechanisms underlying the t(15;17) translocation specific for acute promyelocytic leukaemia (APL). Together with providing new insights into the pathogenesis of the disease, the identification of breakpoints within the RAR-alpha and PML loci on chromosomes 17 and 15 has allowed a new relevant diagnostic tool for the recognition of this leukaemic form. We report the molecular characterization of 6 cases of acute myelogenous leukaemia (AML) in which a diagnosis of typical M3 by conventional morphocytochemistry (FAB criteria) was not accompanied by cytogenetic evidence of the specific t(15;17) aberration. DNA rearrangements were documented in all cases at the PML and RAR-alpha loci. Moreover, in 4 cases also analysed by Northern blot hybridization, we could detect aberrant RAR-alpha transcripts. These findings highlight the specificity of PML/RAR-alpha rearrangements in APL, whereas the lack of t(15;17) may be attributed to sub-microscopic translocations as well as to the presence of non-neoplastic cells undergoing mitosis in the samples examined for karyotype.
Lo Coco
F
F
Human Biopathology Department, University La Sapienza of Rome, Italy.
Diverio
D
D
D'Adamo
F
F
Avvisati
G
G
Alimena
G
G
Nanni
M
M
Alcalay
M
M
Pandolfi
P P
PP
Pelicci
P G
PG
D000293:Adolescent; D000328:Adult; D015152:Blotting, Northern; D015139:Blotting, Southern; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology; D002352:Carrier Proteins / Q000235:genetics*; D002675:Child, Preschool; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D016130:Immunophenotyping; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; D018168:Receptors, Retinoic Acid; D014157:Transcription Factors / Q000235:genetics*; D014178:Translocation, Genetic; D025521:Tumor Suppressor Proteins
D002352:Carrier Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; D018168:Receptors, Retinoic Acid; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human