Fig 2: CSF2 regulates the pro-tumor phenotype and function of MSCs.A In vitro tropism of MSCs towards HGC-27 cells assessed via a transwell system. Original magnification: ×100. Scale bar = 50 μm. B qRT-PCR analysis of FAP and α-SMA expression in MSCs and P-MSCs. C Western blot analyses of FAP and α-SMA expression in MSCs and P-MSCs. D Luminex assay to determine the inflammatory cytokine profile in the supernatants from MSCs and P-MSCs. E Cell viability assay for HGC-27 cells treated with the supernatants from MSCs and P-MSCs. F Colony formation assays for HGC-27 cells treated with the supernatants from MSCs and P-MSCs. G Transwell migration assay for HGC-27 cells treated with the supernatants from MSCs and P-MSCs. Original magnification: ×100. Scale bar = 50 μm. H CCK-8 assay for IC50 of 5-FU in HGC-27 cells treated with the supernatants from MSCs and P-MSCs. I Flow cytometry analyses of the apoptotic rate of HGC-27 cells exposed to 5-FU. *P < 0.05; **P < 0.01; ***P < 0.001.

Fig 3: Proposed model for the role of IGF2BP2/CSF2/Notch1 axis in MSC reprogramming.The gastric cancer microenvironment induces increased expression of IGF2BP2, a crucial m6A reader protein, in MSCs. IGF2BP2 targets CSF2 in an m6A-dependent manner, enhancing the stability of CSF2 RNA and its expression. The upregulation of CSF2 leads to the ubiquitination of Notch1 and subsequent inhibition of Notch signaling. Consequently, MSCs undergo remodeling to acquire a tumor-promoting phenotype in gastric cancer.

Fig 4: Senescent cells promote the migration of breast cancer cells via secreted bFGF and GM-CSF. (A-B) Representative crystal violet-stained images of transwell migration of MDA-MB-231, MDA-MB-468 and MCF-7 cells co-cultured with conditioned medium from young (PD29) or senescent (PD61) BJ cells, which were left untreated (None) or incubated with neutralizing antibodies against β-actin (1 ng/ml), bFGF (1 ng/ml), GM-CSF (5 ng/ml) or both bFGF and GM-CSF for 12 h (A), and quantification of number of migrated cells per field (mean ± SD, n = 3) (B). At least 5 randomly chosen 20X fields were counted for each of the triplicates (C-D) Representative crystal violet-stained images of transwell migration of MDA-MB-231, MDA-MB-468 and MCF-7 cells co-cultured with conditioned medium from young (PD29) or senescent (PD61) BJ cells transduced with shRNA control (SC) or shRNAs for bFGF or GM-CSF for 20 h (C), and quantification of number of migrated cells per field (mean ± SD, n = 3) (D). At least 5 randomly chosen 20X fields were counted for each of the triplicates. (B, D) ns, not significant; * p < 0.05; ** p < 0.01; and *** p < 0.001 between indicated groups in unpaired, 2-sample t tests (dotted lines) or One-way ANOVA corrected for multiple comparisons using Tukey’s multiple comparison correction adjustment (solid lines)

Fig 5: IGF2BP2 modulates CSF2 m6A modification to induce MSC reprogramming.A In vitro tropism of MSCs towards HGC-27 cells assessed via a transwell system. Original magnification: ×100. Scale bar = 50 μm. B, C qRT-PCR (B) and western blot (C) analyses of FAP and α-SMA expression in MSCs from different groups. D Luminex analyses of the inflammatory factor profile in the supernatants from MSCs. E, F The proliferation of HGC-27 cells following exposure to the supernatants from different MSCs was assessed by cell viability (E) and colony formation assays (F). G Transwell assay for the migration of HGC-27 cells upon treatment with the supernatants from different MSCs. Original magnification: ×100. Scale bar = 50 μm. H CCK-8 assay for IC50 of 5-FU in HGC-27 cells treated with the supernatants from different MSCs. I Flow cytometric analyses of the apoptotic rate of HGC-27 cells after exposure to 5-FU. *P < 0.05; **P < 0.01; ***P < 0.001.