Treatment with 4MU/HLX increases in vitro trastuzumab efficacy and decreases HER2-signal transduction in JIMT1 breast cancer cells. (A) Excluded trypan blue, (B) protein expression and activation of HER family receptors pathways, CD44, and CAV1 proteins as analyzed and (C,D,E) quantified by Western blot in JIMT1 breast cancer cells in the presence or absence of trastuzumab and after treatment with 4MU, HLX, or 4MU/HLX. Cells were treated with 1 mM 4MU for 48 h, 1 Unit HLX for 2 h, or 4MU/HLX in the presence of 20 nM trastuzumab for 24 h. (A) Bars, n = 4, mean ± S.E.M, **P < 0.01 based on a Student’s t-test, * compared with control group, $ compared with the nontrastuzumab respective group. (C, D, E) Bars, n = 3, mean ± S.E.M, *P < 0.05 based on a Student’s t-test and compared with the control group, $P < 0.05 based on a Student’s t-test and compared with the nontrastuzumab respective group.