Fig. 4: RBM15 regulates serine and glycine metabolism to induce BC cell growth.

a A diagram depicting serine and glycine metabolism. b, c, f The indicated TNBC cells were transfected with siCon or siRBM15 and subjected to qRT‒PCR analysis with the indicated primers (b) and WB analysis (c, f) with the indicated antibodies. d, e IHC (d) and WB (e) analyses of RBM15 target genes in the mouse samples used in Fig. 2h. The indicated TNBC cells were infected with shRBM15 or shGFP. The cells were maintained for 5 days. The cells were used for WB analysis (g) and for detecting serine and glycine levels using colorimetric kits (h) (S/G: serine and glycine). i Serine and glycine metabolite levels were measured in the mouse samples used in Fig. 2h. j–l MDA-MB-231 cells were infected with shRBM15 or shGFP and transfected with Flag or His-tagged SSP cDNA. The cells were subjected to WB analysis with the indicated antibodies (j), serine and glycine assays (k), and WST-8 assays (l). The data are expressed as the means ± standard deviations (SDs) from three independent replicates. Student’s t test was performed to determine statistical significance (*p < 0.05, **p < 0.01, ***p < 0.005, and ****p < 0.001).