Translocations of the RARalpha gene in acute promyelocytic leukemia.
Acute promyelocytic leukemia (APL) has been recognized as a distinct clinical entity for over 40 years. Although relatively rare among hematopoietic malignancies (approximately 10% of AML cases), this disease has attracted a particularly good share of attention by becoming the first human cancer in which all-trans-retinoic acid (ATRA), a physiologically active derivative of vitamin A, was able to induce complete remission (CR). ATRA induced remission is not associated with rapid cell death, as in the case of conventional chemotherapy, but with a restoration of the 'normal' granulocytic differentiation pathway. With this remarkable medical success story APL has overnight become a paradigm for the differentiation therapy of cancer. A few years later, excitement with APL was further enhanced by the discovery that a cytogenetic marker for this disease, the t(15:17) reciprocal chromosomal translocation, involves a fusion between the retinoic acid receptor alpha (RARalpha) gene and a previously unknown locus named promyelocytic leukemia (PML). Consequence of this gene rearrangement is expression of the PML-RARalpha chimeric oncoprotein, which is responsible for the cellular transformation as well as ATRA response that is observed in APL. Since this initial discovery, a number of different translocation partner genes of RARalpha have been reported in rarer cases of APL, strongly suggesting that disruption of RARalpha underlies its pathogenesis. This article reviews various rearrangements of the RARalpha gene that have so far been described in literature, functions of the proteins encoded by the different RARalpha partner loci, and implications that these may have for the molecular pathogenesis of APL.
Zelent
A
A
Leukemia Research Fund Centre at the Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK. a.zelent@icr.ac.uk
Guidez
F
F
Melnick
A
A
Waxman
S
S
Licht
J D
JD
D034961:Antigens, Nuclear; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins / Q000235:genetics; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000188:drug therapy / Q000235:genetics*; D008894:Milk Proteins; D009363:Neoplasm Proteins / Q000235:genetics; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins / Q000235:genetics; D000090243:Nucleophosmin; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000235:genetics*; D000072482:Retinoic Acid Receptor alpha; D050799:STAT5 Transcription Factor; D015534:Trans-Activators / Q000235:genetics; D014178:Translocation, Genetic / Q000235:genetics*; D014212:Tretinoin
D034961:Antigens, Nuclear; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D008894:Milk Proteins; C120276:NPM-RARalpha protein, human; C050045:NUMA1 protein, human; D009363:Neoplasm Proteins; C412764:NuMa-RARalpha protein, human; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; D015514:Oncogene Proteins, Fusion; C118318:PLZF-RARalpha fusion protein, human; C000607071:RARA protein, human; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; C093476:promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein; D000090243:Nucleophosmin; D014212:Tretinoin