Fig. 4
Adipocyte-secreted factors impair the response of melanoma cells to DTIC. a Calculation of IC50 value of DTIC in CM from 3T3-L1 cells. B16F10 cells were chronically grown in conditioned medium (CM) collected from 3T3-L1 cells for 10 days. These cells were then subjected to DTIC treatment at the indicated concentrations for 48 h. Thereafter, MTT assay was performed. b Immunofluorescence confocal staining of P-gp, Cav-1, and FASN in B16F10 cells cultured in CM collected from 3T3-L1 cells (scale bar = 20 μm). c Rh-123 efflux assay in B16F10 cells cultured in the CM from 3T3-L1 cells. d, e Long-term survival assay in B16F10 cells cultured in the CM from adipocytes in the presence of inhibitors of FASN, Cav-1, and P-gp, either alone or together with DTIC (d). Data were quantitated using ImageJ software (e). The data are representative of experiments performed three times; PA = preadipocytes; ID = differentiated adipocytes; Orli = orlistat; Ceru or C = cerulenin; MCD or M = methyl β-cyclodextrin; Vera or V = verapamil. The results are given as means ± standard deviation; *p < 0.05, **p < 0.01, ***p < 0.001, and *****p < 0.0001 denote significant differences between the groups; NS non-significant