Variant acute promyelocytic leukaemia with novel NAB2::RARA fusion shows clinical all-trans retinoic acid and arsenic trioxide sensitivity

Report of IRF2BP1 as a novel partner of RARA in variant acute promyelocytic leukemia

IRF2BP1 breaked in the middle of exon 1 at the c.322 position and fused with RARA intron 2 which is located at 3717 bp upstream of its exon 3. The fusion produced a new intron by forming a paired splicing donor GT at 9 bp downstream of RARA breakpoint and acceptor AG at the 5' end of RARA exon 3. The IRF2BP1::RARA fusion gene leads a fusion transcript involving IRF2BP1 exon 1 and RARA exon 3, linked by a 9-bp fragment derived from RARA intron 2. The patient with IRF2BP1::RARA has same clinical features of APL.

Arsenic trioxide: applications, mechanisms of action, toxicity and rescue strategies to date

Arsenical medicine has obtained its status in traditional Chinese medicine for more than 2,000 years. In the 1970s, arsenic trioxide was identified to have high efficacy and potency for the treatment of acute promyelocytic leukemia, which promoted many studies on the therapeutic effects of arsenic trioxide. Currently, arsenic trioxide is widely used to treat acute promyelocytic leukemia and various solid tumors through various mechanisms of action in clinical practice; however, it is accompanied by a series of adverse reactions, especially cardiac toxicity. This review presents a comprehensive overview of arsenic trioxide from preclinical and clinical efficacy, potential mechanisms of action, toxicities, and rescue strategies for toxicities to provide guidance or assistance for the clinical application of arsenic trioxide.