Unexpected heterogeneity of PML/RAR alpha fused mRNA detected by nested polymerase chain reaction in acute promyelocytic leukemia.
We have analyzed ten APL patients using reverse transcription polymerase chain reaction (RT-PCR) technique to detect PML/RAR alpha fused mRNA. All patients in this study had PML/RAR alpha fused mRNA (three cases of the short type and seven cases of the long type), although the chromosomal translocation t(15;17) was not detected in one patient. After ethidium bromide staining, two-thirds of the short type and all cases of the long type were found to have multiple PCR products (192 and 93 base pair (bp) bands in the short type and 666, 522, 263, and 164 bp in the long type). A total of six distinct fused mRNAs were sequenced (P1R1, P1R2, P3R1, P2R1, and P2R2). Southern hybridization analysis showed only one rearranged band in each of the patients. These results suggest that the longest mRNAs in each type are the authentic fused mRNAs and the other smaller mRNAs are generated through splicing events. In RAR alpha, a novel fusion point (R2) was identified within the fourth exon. This uncommon splicing may be caused by the instability of the splicing mechanism of the rearranged PML/RAR alpha gene. Among the ten APL patients, no correlation was observed between the type of fused mRNA and the clinical characteristics examined.
First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
A
A
Matsuoka
K
K
Miyamura
N
N
Emi
T
T
Tahara
M
M
Tanimoto
T
T
Naoe
R
R
Ohno
A
A
Kakizuka
R M
RM
Evans
H
H
Saito
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D005260:Female; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D016133:Polymerase Chain Reaction; D000071156:Promyelocytic Leukemia Protein; D012326:RNA Splicing; D012333:RNA, Messenger / Q000032:analysis*; D012334:RNA, Neoplasm / Q000032:analysis*; 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; D015514:Oncogene Proteins, Fusion; D000071156:Promyelocytic Leukemia Protein; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D018168:Receptors, Retinoic Acid; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human