High prevalence of MEF2D fusion in human B‐cell precursor acute lymphoblastic leukemia cell lines

Data S1: Supporting information. Table S1 Primers for RT-PCR of MEF2D fusion oncogenes. Table S2. Source of agents used in in vitro drug sensitivity analyses Figure S1 Structure of MEF2D fusion in BCP-ALL cell lines. Upper figures indicate the structure of wild-type MEF2D and the fusion partner proteins. Lower figures indicate predicted protein structure (left) and nucleotide sequence (right) in each MEF2D fusion. Names of cell lines are indicated on the left end Figure S2 Duration of cell culture until cell line establishment in BCP-ALL cell lines with precise record. Precise records of cell line establishment were available in six YA series cell lines (YAMN73, YAMN74, YAMN90R, YAMN91, YACL95, and YAMN96) and in two KCB series cell lines (KCB1 and KCB4). YAMN74 and YAMN96 were MEF2D fusion-positive ALL cell lines. YAMN73, YAMN91, and KCB1 were BCR-ABL1-positive cell lines, YAMN90R was TCF3-PBX1-positive cell line, YACL95 was KMT2A fusion-positive cell line, and KCB4 was negative for known fusion genes. Vertical line indicates duration (days) of cell culture until cell line establishment. P value in Mann-Whitney U test is shown Figure S3 Genetic and clinical characteristics of human BCP-ALL cell lines Figure S4 The percentages of BCP-ALL cell lines derived from the samples at diagnosis and those derived from the samples at relapse. Basic records of cell line establishment were available in 16 MEF2D fusion-positive (MEF2D+) ALL cell and in 57 MEF2D fusion-negative (MEF2D−) BCP-ALL cell lines. Blue columns indicate the percentage of cell lines established from the samples at diagnosis, while orange columns indicate the percentage of cell lines established from the samples at relapse. P value in Fisher's exact test is shown Figure S5 Immunophenotypic characteristics of MEF2D fusion + ALL cell lines. A, The percentage of cell lines with cytoplasmic μ-chain positivity over 40% in each BCP-ALL subgroup is indicated. B, Surface expression level of CD10 in each cell line is plotted as a scatter diagram. P values in chi-square test (cytoplasmic μ-chain) and Mann-Whitney U test (CD10) are shown Figure S6 Cell cycle analyses in BCP-ALL cell lines. A, MEF2D fusion-positive (MEF2D+) (indicated by red circles) and MEF2D fusion-negative (MEF2D−) (indicated by gray circles) BCPALL cell lines were cultured with fresh media at a density of 0.5 × 105/mL for 24 hours, and then cell cycle analyses using flow cytometry after PI staining were performed. The median percentage of G0/G1 dormancy phase in three independent analyses in each cell line is plotted as a scatter diagram. P value in Mann-Whitney U test is shown. B, The percentage of cell lines with a high proportion of dormant cells (G0/G1 > 66.7%). Green columns indicate the cell lines (G0/G1 > 66.7%). P value in Fisher's exact test is shown Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.