Fig. 4

S. aureus effect on melanoma clustering is likely to be mediated by lipids. Quantification of ZMEL1 melanoma cell cluster size (µm2) after 7 days of culture in medium alone or plus S. aureus USA300 bacterial supernatant. (A) Supernatants were collected from S. aureus USA300 bacteria grown in RPMI medium alone Media), or RPMI medium supplemented with either 2% FBS or 2% BSA followed by culturing with melanoma cells. (B) Supernatants collected from S. aureus USA300 bacteria grown in RPMI medium alone (Media) were left untreated or treated with dextran-coated charcoal (+Charcoal) followed by culturing with melanoma cells. (C) Supernatants collected from S. aureus USA300 bacteria grown in RPMI medium alone (Media) were left untreated or treated with Amberlite-XAD4 (+Amberlite) followed by culturing with melanoma cells. Experiments were conducted at least three times. Dots represent independent replicates. Error bars indicate the mean±s.e.m. P-values were calculated by two-way ANOVA. **P<0.01; ***P<0.001; ****P<0.0001. ns, not significant.