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. Author manuscript; available in PMC: 2011 May 9.
Published in final edited form as: Urol Oncol. 2009 JAN-FEB;27(1):53–63. doi: 10.1016/j.urolonc.2008.07.036

Figure 3. Restoration of hormonal sensitivity to LTLTCa cells with trastuzumab (Herceptin).

Figure 3

LTLTCa cells were transferred to IMEM without phenol red before they were plated into 96-well plates (1000 cells/well) and allowed to attach overnight. The next day, they were treated with the indicated agents for a total of 6 days. The cell viability was measured using the MTT assay as described [68]. A) Effect of combination of letrozole and trastuzumab in LTLT-Ca cells. Combination of letrozole plus trastuzumab was significantly better than single drug treatment or control, p < 0.0001 (10-12M-10-9M), p < 0.05 (10-8M-10-5M). B) Effect of combining trastuzumab with AEs tamoxifen, fulvestrant and AIs exemestane, anastrozole in LTLT-Ca cells. The cell viability was found to be significantly lower in groups treated with the combination of trastuzumab plus AI or AE versus control (p<0.0001) or trastuzumab alone (p<0.0001) or the endocrine agent alone (p<0.0001). C) Effect of estradiol (E2) on proliferation of MCF-7Ca and LTLT-Ca cells in presence or absence of trastuzumab (Herceptin) pretreatment. When pre-treated with herceptin (100μg/mL), proliferation of LTLT-Ca cells was significantly stimulated in response to E2 at concentrations of 10-12M - 10-7M when compared to E2 alone (p <0.0001). When MCF-7Ca cells were pretreated with herceptin, E2 stimulated proliferation was increased at concentrations 10-11M - 10-10M (p = 0.02 and 0.03 respectively) [68].