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Original Article
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Korean J Med. 2008;75(4):409-411.
- 논평: PML/RAR-α 유전자 동형의 임상적 의의가 있는가?
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엄 현 석
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- Do PML/RAR-α isoforms have clinical significance in patients with acute promyeloctyic leukemia?
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Hyeon-Seok Eom
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1Department of Cardiology, Catholic University of Daegu College of Medicine, Daegu, Korea
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- Abstract
- Acute promyelocytic leukemia (APL) is characterized by a specific t (15;17) translocation which produce a PML/RAR-
α fusion messenger RNA and by effectiveness of all-trans retinoic acid (ATRA) differentiation therapy. Breakpoints within
PML intron 3 (bcr 3) produce a short PML/RAR-α isoform (S-isoform), whereas breakpoints within PML intron 6 (bcr
1) result in a longer form (L-isoform). Additionally, breakpoints within PML exon 6 (bcr 2) make a variable length
transcript (V-isoform) in a small number of patients. The influence of breakpoint site on patient outcome remains
controversial. Previous reports showed that patients with S-isoform have an increased incidence of clinical relapse and
shorter survival compared to those with L-isoform. Others reported no difference in DFS between these patients groups.
In this issue, Lee et al. reported that there were 58 L-isoform (62.1%), 32 S-isoform (34.0%), 4 V-isoform (4.3%) and,
no significant prognostic factor for EFS from induction therapy using anthracycline plus ATRA among 94 patients with
APL. They concluded pretreatment clinical characteristics and treatment outcomes were not significantly different
according to PML/RAR-α isoform types in this induction group. Recently, it was reported that FLT3/ITD mutation was
frequently associated with S-isoform and with the M3v form of leukemia and CNS relapse in APL was mostly related
to S-isoform. With previous studies including this article, outcomes of different types of PML/RAR-α isoforms are not
conclusive. Future researches need to be focused not only on clinical outcomes of different types of PML/RAR-α
isoforms, but also clinical relevance of PML/RARA-α mRNA isoforms with other prognostic factors and particular clinical
characteristics. (Korean J Med 75:409-411, 2008)
Keywords :Acute promyelocytic leukemia, PML/RAR-α isoform
