Figure 2.

METTL14 inhibited ccRCC metastasis via m⁶A modification.

(A and B) qRT-PCR and western blotting analysis were used to confirm overexpression and knockdown of METTL14 in 786-O and Caki-1 cells. (C and D) Transwell assay and wound healing assay were performed to detect the migratory and invasive abilities of ccRCC cells after METTL14 knockdown or overexpression. Magnification, 100×. (E) Transwell assay showed that METTL14-WT, but not METTL14-R298P, could reverse the effect of METTL14 knockdown on 786-O cell migration and invasion. Magnification, 100×. WT, wild type; Mut, R298P mutant. (F) OSRC-2 shMETTL14-1 or sh-NC cells labeled with luciferase expression were injected into the renal capsule of the mice (n = 10 per group). Representative bioluminescent images showing systemic metastasis. (G) The ratio of lung metastasis was higher in the shMETTL14-1 group (7/10) than in the sh-NC group (2/10). (H) Luciferase-tagged OSRC-2 shMETTL14-1 or sh-NC cells were injected into mice tail vein (n = 8 per group). Representative bioluminescent images showing lung metastasis. Quantification of the bioluminescent signal intensities (photons/s/cm²/sr) in the lungs was carried out after 6 weeks. (I) Micrometastasis in lungs harvested from the shMETTL14-1 and sh-NC groups were evaluated by H&E staining. Scale bars represent 2.5 mm. Representative H&E staining images of the lung sections are shown. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001; ns, not significant. Data are presented as the mean ± SD of at least three independent experiments.