Kravchenko-Balasha Nataly, Shin Young Shik, Sutherland Alex, Levine R D, Heath James R
NanoSystems Biology Cancer Center, Division of Chemistry, California Institute of Technology, Pasadena, CA 91125;
Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095;
Proc Natl Acad Sci U S A. 2016 May 17;113(20):5520-5. doi: 10.1073/pnas.1602171113. Epub 2016 May 2.
Controlling cell migration is important in tissue engineering and medicine. Cell motility depends on factors such as nutrient concentration gradients and soluble factor signaling. In particular, cell-cell signaling can depend on cell-cell separation distance and can influence cellular arrangements in bulk cultures. Here, we seek a physical-based approach, which identifies a potential governed by cell-cell signaling that induces a directed cell-cell motion. A single-cell barcode chip (SCBC) was used to experimentally interrogate secreted proteins in hundreds of isolated glioblastoma brain cancer cell pairs and to monitor their relative motions over time. We used these trajectories to identify a range of cell-cell separation distances where the signaling was most stable. We then used a thermodynamics-motivated analysis of secreted protein levels to characterize free-energy changes for different cell-cell distances. We show that glioblastoma cell-cell movement can be described as Brownian motion biased by cell-cell potential. To demonstrate that the free-energy potential as determined by the signaling is the driver of motion, we inhibited two proteins most involved in maintaining the free-energy gradient. Following inhibition, cell pairs showed an essentially random Brownian motion, similar to the case for untreated, isolated single cells.
控制细胞迁移在组织工程和医学中至关重要。细胞运动性取决于营养物质浓度梯度和可溶性因子信号等因素。特别是，细胞间信号传导可能取决于细胞间的分离距离，并能影响大规模培养中的细胞排列。在这里，我们寻求一种基于物理的方法，该方法可识别由细胞间信号传导控制的电位，这种电位会诱导细胞间的定向运动。使用单细胞条形码芯片（SCBC）对数百对分离的胶质母细胞瘤脑癌细胞中的分泌蛋白进行实验性检测，并监测它们随时间的相对运动。我们利用这些轨迹确定了信号传导最稳定的一系列细胞间分离距离。然后，我们对分泌蛋白水平进行了基于热力学的分析，以表征不同细胞间距离下的自由能变化。我们表明，胶质母细胞瘤细胞间的运动可以描述为受细胞间电位影响的布朗运动。为了证明由信号传导确定的自由能电位是运动的驱动力，我们抑制了两种最参与维持自由能梯度的蛋白质。抑制后，细胞对表现出基本随机的布朗运动，类似于未处理的分离单细胞的情况。
