[Molecular study on the distinct isoforms of PML-RAR alpha fusion gene transcripts in acute promyelocytic leukemia].

: The chromosomal translocation t(15; 17) in acute promyelocytic leukemia (APL) results in the production of a fusion gene PML-RAR alpha specific for the disease. Using the retrotranscriptase/polymerase chain reaction (RT/PCR), we cloned several distinct isoforms of PML-RAR alpha fusion transcripts and obtained their nucleic acid sequences. The results showed that the RAR alpha derived sequences were the same in fusion genes while the PML sequences differed as a result of the locations of PML gene breakpoints. The biological significance of this finding should be further studied.