Fig. 7.

Endocrine agents and trastuzumab augment MAPK activity in 3D culture. Comparison of signaling pathway activation in 2D versus 3D culture in response to tamoxifen, fulvestrant and trastuzumab monotherapy and in combination was investigated using Western blotting with accompanying densitometry of normalized blots. For BT474, trastuzumab and endocrine treatments, either as monotherapies (a) or in combination (b), suppressed MAPK signaling in 2D monolayers in contrast to 3D culture, where MAPK activity was maintained or augmented. In the case of MDAMB361 cells, treatment with trastuzumab and endocrine agents, either as single agents (c) or in combination (d), resulted in the loss of MAPK signaling in the 2D context in contrast to 3D culture where MAPK signaling was augmented. C = control, H = trastuzumab (Herceptin), T = tamoxifen, F = fulvestrant