Study Investigates Novel and Rare Fusion Transcripts in Acute Myeloid Leukemia

Novel gene fusion events often occur in acute myeloid leukemia (AML) cases. A recent study, published by Cancer, utilized RNA-sequencing data to identify how ZEB2-BCL11B rearrangement is associated with distinct immune-clinical characteristics.

The researchers investigated the transcriptome of 8 adult AML patients with poorly described chromosomal translocations in order to identify novel and rare fusion transcripts. RNA-sequencing data was integrated through several approaches, such as computational analysis, Sanger Sequencing, fluorescence in situ hybridization, and in vitro studies, according to the study.

“Whole genome sequencing and RNA sequencing (RNA-seq) approaches have allowed the identification of several novel fusions in acute leukemia that remained cryptic by routine cytogenetic analysis,” explained the authors. “It has been shown that normal karyotype AMLs are characterized by the presence of several chimeras, mainly deriving from adjacent genes located on the same chromosome and with complex patterns of partner gene orientation.”

The study identified 7 different fusions with partner genes involving transcription factors (OAZ-MAFK, ZEB2-BCL11B), tumor suppressors (SAV1-GYPB, PUF60-TYW1, CNOT2-WT1) and rearrangements associated with the loss of NF1 (CPD-PXT1, UTP6-CRLF3), according to the results. Additionally, the researchers reported that ZEB2-BCL11B rearrangements co-occurred with FLT3 mutations and were associated with a poorly differentiated or mixed phenotype leukemia.

The results suggested that fusion events contribute to the complexity of AML and typically result from chromosomal rearrangements.

“The identification of fusion events, even when shared by a small subgroup of poorly characterized patents, may be of clinical significance. We validated the presence of nine fusion genes involving either transcription factors, tumor suppressors, or associated with a loss event of candidate genes in AML. We found that the landscape of alterations in AML is not limited to known genes, and that fusion genes, albeit rare, may play an important role in the disease development.”

Reference

Padella A, Simonetti G, Paciello G, et al. Novel and rare fusion transcripts involving transcription factors and tumor suppressor genes in acute myeloid leukemia [published online December 5, 2019]. Cancer. doi: https://doi.org/10.3390/cancers11121951.