ETV6/RUNX1 Fusion Gene Abrogation Decreases the Oncogenicity of Tumour Cells in a Preclinical Model of Acute Lymphoblastic Leukaemia

Abstract

Background: The t(12;21)(p13;q22), which fuses ETV6 and RUNX1 genes, is the most common genetic abnormality in children with B-cell precursor acute lymphoblastic leukaemia. The implication of the fusion protein in leukemogenesis seems to be clear. However, its role in the maintenance of the disease continues to be controversial. Methods: Generation of an in vitro ETV6/RUNX1 knock out model using the CRISPR/Cas9 gene editing system. Functional characterization by RNA sequencing, proliferation assays, apoptosis and pharmacologic studies, and generation of edited-cell xenograft model. Results: The expression of ETV6/RUNX1 fusion gene was completely eliminated, thus generating a powerful model on which to study the role of the fusion gene in leukemic cells. The loss of fusion gene expression led to the deregulation of biological processes affecting survival such as apoptosis resistance and cell proliferation capacity. Tumour cells showed higher levels of apoptosis, lower proliferation rate and a greater sensitivity to PI3K inhibitors in vitro along as a decrease in tumour growth in xenografts models after ETV6/RUNX1 fusion gene abrogation. Conclusions: ETV6/RUNX1 fusion protein seems to play an important role in the maintenance of the leukemic phenotype and could thus become a potential therapeutic target.

Comprehensive Custom NGS Panel Validation for the Improvement of the Stratification of B-Acute Lymphoblastic Leukemia Patients

“…In the sample ID13, in which the ETV6/RUNX1 fusion gene reported by FISH was not detected, a different translocation was observed between chromosomes 5 and 12, involving the ETV6 gene ( Figure S2). The fusion gene ETV6/RUNX1 was also analyzed in the REH cell line and the ETV6/RUNX1 knockout (KO) clones established in previous studies [25]. The ETV6/RUNX1 fusion gene was detected in 100% of cells from the REH cell line, as expected, and the truncator mutation was also found in 100% of the cells in the KO clones (data not shown).…”

“…This cell line has a series of mutations described in previous studies, which are collated online at https://cansarblack.icr.ac.uk/cell-line/REH/mutations. In addition, different clones generated in the laboratory from the REH line by single-cell sorting were used, in which the expression of the fusion protein ETV6/RUNX1 was truncated using the clustered regularly interspaced short palindromic repeats-cas9 (CRISPR/Cas9) system [25].…”

Genetic analysis and clinical significance of a rare t(1;12)(q21;p13) in a patient with high‐risk myelodysplastic syndrome

“…Translocation resulting from the break apart of 12p13 usually involves ETV6 gene in hematologic malignancies, such as t (5;12) (q31‐33; p13) in chronic myelomonocytic leukemia (Apperley et al, 2002; Di Giacomo et al, 2021) and t (12;21) (p13;q22) in ALL (Montaño et al, 2020; Shurtleff et al, 1995). The aryl hydrocarbon receptor nuclear translocator ( ARNT ) gene, also named HIF‐1β , locates in 1q21, which play a critical role in driving tumor growth and metastasis (Lee et al, 2021).…”

An RNAi Screening of Clinically Relevant Transcription Factors Regulating Human Adipogenesis and Adipocyte Metabolism

“…On the other hand, many genes that were found to affect fat cell number ( Table 2 ) were not previously defined as adipogenic factors but are well-known proliferation regulators mostly in cancer cells. For example, GLIS2 and ETV6 have been reported to regulate proliferation in leukemia ( 140 ), HMGA1 in gastric cancer ( 141 ), and FBXW7 in breast cancer ( 142 ). In addition, LRRFIP1 and ZNRD1 have been shown to regulate proliferation via Wnt/β-catenin pathway in mesenchymal stem cells and in tumor cells, respectively ( 143 , 144 ).…”