Satsuki Matsushima | Search PubMed

PubMed2026

T-Cell Leukemia Cell Line Harboring Previously Undescribed CBFB::MYL11 Fusion Exhibits a Genome Profile Implicating Cytoskeletal Abnormality.

INTRODUCTION: Gene fusions involving core binding factors (CBFs), such as CBFB::MYH11, are major contributing factors to leukemia development. The pathogenic mechanism is believed to lie in abnormalities in CBF, however, myosin, the fusion partner, has received little attention. In a preliminary analysis, we identified a previously undescribed fusion transcript, CBFB::MYL11, in RNA-sequencing data from the T-cell leukemia cell line HPB-ALL. We hypothesized that leukemia cells harboring CBFB::MYH11 or CBFB::MYL11 may share a common pathological mechanism involving myosin fusion. METHODS: Fluorescence in situ hybridization was performed to analyze the structure of CBFB::MYL11 and Western blotting was performed to verify the fusion protein in HPB-ALL. Differentially expressed gene (DEG) and gene ontology (GO) analyses were performed on ME-1 harboring CBFB::MYH11 and HPB-ALL to investigate characteristics of gene expression and molecular function. RESULTS: In situ amplification of MYL11 and co-amplification of CBFB and MYL11 on a marker chromosome were observed. Elevated MYH11 and MYL11 expression and significant upregulation of genes related to the cytoskeleton were observed in the ME-1 and HPB-ALL cell lines. Bands consistent with the CBFB::MYL11 fusion protein were observed using Western blotting. CONCLUSION: This study underscores the pathological significance of cytoskeletal abnormalities in leukemia with CBFB/myosin fusion and provides a foundation for further investigation into their molecular mechanisms.

Journal Article↗

PubMed2026

Identification and characterization of ectopic chromosomal amplifications in acute myeloid leukemia cell limes using high-throughput chromosome conformation capture screening.

Despite advanced molecular diagnostics, improving outcomes for refractory acute myeloid leukemia (AML) remains challenging. Although many cancer-related genes are identified, their molecular mechanisms are not fully elucidated. Amplification is a mechanism of cancer-associated gene activation, and ectopic gene amplification may have particularly high pathological significance. However, research on ectopically amplified cancer-associated genes in leukemia remains limited. Here, we evaluated the usefulness of high-throughput chromosomal conformation capture (Hi-C) as a screening method for ectopic gene amplification and assessed whether ectopic amplification of cancer-associated genes may represent a general phenomenon in AML. We screened the U-937 and NB-4 cell lines using in situ Hi-C. Regions appearing as "high-intensity bands" in Hi-C contact maps were identified and validated using fluorescence in situ hybridization (FISH). Additionally, copy number variation analysis was performed using whole-genome sequencing (WGS) to extract cancer-associated genes with ectopic amplification. In the U-937, three genomic regions showing "high-intensity bands" were identified and confirmed as ectopic amplifications-including PDCD1LG2 (PD-L2), CD274 (PD-L1), and JAK2; that is, four copies were detected by WGS, and amplification signals were observed by FISH. In the NB-4, four such regions were detected, including MYC and KRAS, with expression level of 498 transcripts per million (TPM) and 34 TPM, respectively. Copy number variation analysis further identified multiple cancer-associated genes with ectopic amplification. Overall, these findings demonstrate the presence of ectopic amplification of cancer-associated genes in AML cell lines and support the usefulness of Hi-C as a screening method for detecting such genomic alterations.

Acute myeloid leukemia↗