Fig. 3: FLAD1 promotes TNBC proliferation and migration in an enzymatic-dependent manner.

a Schematic of the riboflavin metabolic pathway and FLAD1 enzymatic activity site. b HCC1806 and Hs578T cells expressing the control vector, WT FLAD1 or FLAD1-R530C were assessed by western blot analysis. c, d The effects of the indicated TNBC cells expressing the control vector, WT FLAD1 or FLAD1-R530C on proliferation were evaluated using CCK-8 (c) and colony formation (d) assays. e Transwell assays were performed to evaluate the effects of the indicated TNBC cells expressing the control vector, WT FLAD1 or FLAD1-R530C on migration. Scale bars, 100 μm. f The overexpression efficiency of WT and R530C mutant FLAD1 was assessed by western blot in LM2-4175 cells. g, h LM2-4175 cells expressing the control vector, WT FLAD1 or FLAD1-R530C were injected orthotopically into the mammary fat pad of 6-week-old BALB/c female nude mice, with six mice per group. After 30 days, tumors were harvested, and both their volume and weight (g) were measured. Representative image (h) is presented. Graph bars represent mean ± SEM, and P value was calculated by two-tailed Student’s t-test. Results in (c) represent biologically independent experiments of n = 3. b, d, e, f n = 3 independent experiments, a representative example is shown. Source data are provided as a Source Data file.