Fig 2: METTL13 knockdown inhibited the survival and growth of human AML cells.A and B Validation of the knockdown effect of METTL13 using RT-qPCR and Western blot in HL-60 and K562 cells. C Representative growth images of HL-60 and K562 cells on day 4 after METTL13 knockdown. D Proliferation trend of HL-60 and K562 cells by cell counting after METTL13 knockdown. E and F Cell cycle distribution of HL-60 and K562 cells conducted by flow cytometry on day 4 after METTL13 knockdown. G and H Percentages of apoptotic HL-60 and K562 cells were conducted by flow cytometry on day 4 after METTL13 knockdown. I and J Expression analysis of CD11b in HL-60 cells on day 4 after METTL13 knockdown. Data were presented as mean ± SD (Student’s test, *p < 0.05, **p < 0.01, ***p < 0.001).

Fig 3: METTL13 knockdown suppressed the survival of AML cells in vivo.A Schematic diagram of in vivo experimental design. B GFP+ leukemic cells in peripheral blood were analyzed using flow cytometry as indicated. C The trend in body weight variation across the four groups of mice. D Kaplan–Meier survival curves of four groups of mice. Differences were compared by the log-rank test. E and F Size and weight of spleen and liver of four groups of mice. G Representative images of tumor cell infiltration in spleen and liver using H&E staining. The yellow arrows pointed to the tumor lesion. The white dashed box outlined the further magnified field of view. The green arrows point to the tumor cells exhibiting pronounced atypia. Data were presented as mean ± SD (Student’s test, *p < 0.05, **p < 0.01, ***p < 0.001).

Fig 4: METTL13 was upregulated and associated with poor prognosis of AML.A Expression level of METTL family in AML patients from TCGA database. The members confirmed to promote AML progression in other research were marked in blue (METTL1/3/14/16), while the focus in this study, METTL13, was marked in red. B Expression of METTL13 in healthy individuals, clinical AML patients and cell lines. C Expression of METTL13 in AML and non-matched normal samples in the TCGA and GTEx databases. D Western blotting using normal bone marrow of healthy individuals and AML patients, and cell lines (HL-60, K562, U937, MOLM-13, MV-4-11, KG1a and Kasumi-1). Fluorescence intensity was quantified by Fiji software. E Correlation between METTL13 and overall survival of AML patients from GEPIA database (http://gepia.cancer-pku.cn). Data were presented as mean ± SD (Student’s test, *p < 0.05, ***p < 0.001).

Fig 5: Re-expression of METTL13 rescued the proliferation defect induced by METTL13 knockdown in HL-60 cells.A and B Validation of the exogenous expression effect of METTL13 after METTL13 knockdown by RT-qPCR and western blot in HL-60 cells. C–I Ectopic expression of METTL13 rescued the proliferation of METTL13-knockdown HL-60 cells: C growth curves, D, E cell cycle, F, G apoptosis, and H, I differentiation.