Rearrangement of the retinoic acid receptor gene in acute promyelocytic leukemia
Chang, K.S.; Trujillo, J.M.; Ogura, T.; Castiglione, C.M.; Kidd, K.K.; Zhao, S.R.; Freireich, E.J.; Stass, S.A.
Leukemia 5(3): 200-204
1991
ISSN/ISBN: 0887-6924 PMID: 1849600 Document Number: 371641
The retinoic acid receptor-alpha (RAR-.alpha.) gene was previously localized to chromosome 17q21, a region close to the t(5;17)(q22;q21) abnormality in acute promyelocytic leukemia (APL). We used the RAR-.alpha. gene as a probe and found that eight of nine APL patient samples with t(15;17) (q22;q21) showed rearranged bands. A tenth APL patient was diploid and demonstrated no rearrangement. One patient who had rearrangement as an acute leukemia did not have rearrangement in remission. The results obtained from intron/exon mapping of the RAR-.alpha. gene demonstrated that breakpoints of seven of the eight patients occurred within intron 1. Northern blot analysis of leukemic samples indicated the expression of two RAR-.alpha. mRNA of 2.7 and 3.7 kb. However, two additional mRNA and 4.1 and 3.2 kb were found in an APL patient. We conclude that the RAR-.alpha. gene is directly involved in the t(15;17) translocation in APL and may transcribe aberrant messages.