Life Sciences Division, Lawrence Berkeley National Laboratory, University of California Berkeley, Mailstop 977R225A, 1 Cyclotron Road, Berkeley, CA 94720, USA.
Breast Cancer Res Treat. 2010 Jul;122(1):35-43. doi: 10.1007/s10549-009-0502-2. Epub 2009 Aug 22.
Development of effective and durable breast cancer treatment strategies requires a mechanistic understanding of the influence of the microenvironment on response. Previous work has shown that cellular signaling pathways and cell morphology are dramatically influenced by three-dimensional (3D) cultures as opposed to traditional two-dimensional (2D) monolayers. Here, we compared 2D and 3D culture models to determine the impact of 3D architecture and extracellular matrix (ECM) on HER2 signaling and on the response of HER2-amplified breast cancer cell lines to the HER2-targeting agents Trastuzumab, Pertuzumab and Lapatinib. We show that the response of the HER2-amplified AU565, SKBR3 and HCC1569 cells to these anti-HER2 agents was highly dependent on whether the cells were cultured in 2D monolayer or 3D laminin-rich ECM gels. Inhibition of beta1 integrin, a major cell-ECM receptor subunit, significantly increased the sensitivity of the HER2-amplified breast cancer cell lines to the humanized monoclonal antibodies Trastuzumab and Pertuzumab when grown in a 3D environment. Finally, in the absence of inhibitors, 3D cultures had substantial impact on HER2 downstream signaling and induced a switch between PI3K-AKT- and RAS-MAPK-pathway activation in all cell lines studied, including cells lacking HER2 amplification and overexpression. Our data provide direct evidence that breast cancer cells are able to rapidly adapt to different environments and signaling cues by activating alternative pathways that regulate proliferation and cell survival, events that may play a significant role in the acquisition of resistance to targeted therapies.
开发有效和持久的乳腺癌治疗策略需要对微环境对反应的影响有一个机械的理解。以前的工作表明，细胞信号通路和细胞形态学受到三维（3D）培养的显著影响，而不是传统的二维（2D）单层培养。在这里，我们比较了 2D 和 3D 培养模型，以确定 3D 结构和细胞外基质（ECM）对 HER2 信号以及对 HER2 扩增乳腺癌细胞系对 HER2 靶向药物曲妥珠单抗、帕妥珠单抗和拉帕替尼反应的影响。我们表明，HER2 扩增的 AU565、SKBR3 和 HCC1569 细胞对这些抗 HER2 药物的反应高度依赖于细胞是在 2D 单层还是 3D 层粘连蛋白丰富的 ECM 凝胶中培养。当在 3D 环境中生长时，抑制β1 整合素，一种主要的细胞-ECM 受体亚基，显著增加了 HER2 扩增的乳腺癌细胞系对人源化单克隆抗体曲妥珠单抗和帕妥珠单抗的敏感性。最后，在没有抑制剂的情况下，3D 培养对 HER2 下游信号有很大的影响，并在所有研究的细胞系中诱导 PI3K-AKT-和 RAS-MAPK 通路激活之间的转换，包括缺乏 HER2 扩增和过表达的细胞。我们的数据提供了直接的证据，表明乳腺癌细胞能够通过激活调节增殖和细胞存活的替代途径，快速适应不同的环境和信号线索，这些事件可能在获得对靶向治疗的耐药性方面发挥重要作用。
