Fig. 7. ASP/NAM suppresses tumor metastasis via promoting METTL3 acetylation and fine-tuning the nuclear and cytosolic functions of METTL3.

a LM2 cells infected with the indicated lentiviruses were injected into the mammary fat pads of nude mice. Representative bioluminescent images (BLI) of mice with spontaneous lung metastasis (left panel), and quantification of BLI (right panel) are shown. n = 6 mice per group. From left to right: ^***P = 0.0004, ^**P = 0.002, ns P = 0.69, respectively, by two-sided t test. b Representative H&E staining (left panel) and quantification (right panel) analysis of lung metastasis in a. n = 6 mice per group. Scale bars, 2 mm. From left to right: ^***P = 5.94e-05, ^**P = 0.0019, ns P = 0.64, respectively, by two-sided t test. c METTL3 reconstituting LM2 cells were injected into the mammary fat pads of nude mice. Representative BLI of mice with spontaneous lung metastasis following daily treatment with ASP/NAM for 30 days (left panel), and quantification of BLI (right panel) are shown. n = 6 mice per group. From left to right: ^*P = 0.0142, ^**P = 0.0018, ns P = 0.73, ns P = 0.79, respectively, by two-sided t test. d Representative H&E staining (left panel) and quantification (right panel) analysis of lung metastasis in c. n = 6 mice per group. Scale bars, 2 mm. From left to right: ^***P = 0.0001, ^***P = 0.0003, ns P = 0.47, ns P = 0.29, respectively, by two-sided t test. e LM2 cells infected with the indicated lentiviruses were injected into the mammary fat pads of nude mice. Representative bioluminescent images (BLI) of mice with spontaneous lung metastasis following daily treatment with ASP/NAM for 30 days (left panel), and quantification of BLI (right panel) is shown. n = 6 mice per group. From left to right: ^**P = 0.0012, ^***P = 0.0005, ns P = 0.70, respectively, by two-sided t test. f Representative H&E staining (left panel) and quantification (right panel) analysis of lung metastasis in e. n = 6 mice per group. Scale bars, 2 mm. From left to right: ^**P = 0.0034, ^***P = 0.0002, ns P = 0.80, respectively, by two-sided t test. g IP and IB analysis of acetyl-K177 METTL3 levels in xenografted tumors. h, i Representative IHC staining (h) and quantification of cytoplasmic METTL3 (i) in xenografted tumors. Scale bars, 25 μm. n = 6 mice per group. ^***P = 3.07e-06 by two-sided t test. j LC-MS/MS quantification of the m⁶A/A ratio in polyadenylated RNA isolated from xenografted tumors. n = 5 mice in WT, WT + A/N and KQ + A/N group, n = 4 mice in per other groups. From left to right: ^***P = 0.0003, ^*P = 0.020, ns P = 0.13, ^*P = 0.031, ns P = 0.34, respectively, by two-sided t test. k IP and IB analysis of acetyl-K177 METTL3 levels in tissue lysates extracted from fresh human breast cancer samples. All data are represented as mean ± SEM. All P values were calculated by Student’s t test. Source data are provided as a Source Data file.