Fig. 2

Tumour METTL3 level was positively related to intratumoural CD33⁺ MDSCs in vivo and CC-derived MDSCs in vitro. a The association between METTL3 expression in tumour cells and the expression of METTL3 in TILs (R = 0.264, P < 0.001). b The association between METTL3 expression in tumour cells and intratumoural CD33⁺ MDSC number (R = 0.145, P = 0.041). c The association between METTL3 expression in TILs and intratumoural CD33⁺ MDSC number (R = 0.182, P = 0.011). CD33⁺ cells were isolated from PBMCs of healthy donors with human anti-CD33 beads, and the METTL3 levels in CD33⁺ cells or HeLa cells were knocked down by siMETTL3. d Immunoblotting showed the METTL3 expression in CD33⁺ cells with or without METTL3 knockdown. e HLA-DR⁻CD33⁺CD11b⁺ MDSC induction from CD33⁺ cells in the presence of siMETTL3 or siControl (SiNC). A statistical graph is included for the comparison between the indicated groups. f Immunoblotting showed METTL3 expression in HeLa cells with or without METTL3 knockdown. g Tumour-associated HLA-DR⁻CD33⁺CD11b⁺ MDSC induction from CD33⁺ cells in coculture with Hela-siMETTL3 or Hela-siControl cells in a Transwell System for 48 h. A statistical graphs is included for the comparison between the indicated groups. Representative flow cytometry density plots (left) and statistical bar chart (right). The statistical analysis was performed using Spearman’s correlation and linear regression. R, Spearman’s correlation, is the correlation coefficient. The experiments in e, g were performed at least three times, and the data were plotted as the mean ± SEM. Statistics were conducted with an unpaired Student’s t test, **P < 0.01, and ***P < 0.001 vs. the corresponding control