Fig. 3

Adipocyte-conditioned medium-induced resistance of tumor cells to lapatinib is specific to adipocyte cell lines and the constant presence of adipocyte-conditioned medium is necessary to observe the resistance. A) BT-474 cells were seeded on the day 1 in control medium or adipocyte-conditioned medium (#3T3-CM) and the medium were changed on day 2 prior exposure to lapatinib and evaluation of IC50. n ≥ 3. B, C and D BT-474 cells were cultured in #3T3CM, in human adipocyte-conditioned medium (#hmads), in fibroblast-conditioned medium (NIH-3T3-CM), in preadipocyte-conditioned medium (3T3F442A-CM) or in conditioned medium from fresh human adipocytes from three donors (ASC18032, ASC15011 and ASC18019). We evaluated the IC50 of lapatinib in each condition. n ≥ 3. The ratio of IC50 for cells in control medium to the IC50 for cells in the various conditions. * p < 0,05 ** p < 0,01