Fig. 4

3D culture attenuates the therapeutic response of ER + Her2+ cells. BT474 (a) and MDAMB361 (b) cells were grown for 10 days as 2D monolayers or as 3D cultures in Matrigel and their proliferative response to trastuzumab and endocrine monotherapy or their combination assessed using coulter counting. The growth inhibitory effects of trastuzumab and endocrine therapy on day 10, either as single agents or in combination, were significantly attenuated in 3D vs. 2D cultures. * p < 0.05, ** p < 0.001. t-test. C = control, H = trastuzumab (Herceptin), T = tamoxifen, F = fulvestrant