State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Exp Cell Res. 2013 Nov 1;319(18):2812-21. doi: 10.1016/j.yexcr.2013.07.020. Epub 2013 Jul 26.
CD20, a membrane protein highly expressed on most B-cell lymphomas, is an effective target demonstrated in clinical practice for treating B-cell non-Hodgkin's lymphoma (NHL). Rituximab is a monoclonal antibody against CD20. In this work, we applied atomic force microscopy (AFM) to map the nanoscale distribution of CD20 molecules on the surface of cancer cells from clinical B-cell NHL patients under the assistance of ROR1 fluorescence recognition (ROR1 is a specific cell surface marker exclusively expressed on cancer cells). First, the ROR1 fluorescence labeling experiments showed that ROR1 was expressed on cancer cells from B-cell lymphoma patients, but not on normal cells from healthy volunteers. Next, under the guidance of ROR1 fluorescence, the rituximab-conjugated AFM tips were moved to cancer cells to image the cellular morphologies and detect the CD20-rituximab interactions on the cell surfaces. The distribution maps of CD20 on cancer cells were constructed by obtaining arrays of (16×16) force curves in local areas (500 × 500 nm(2)) on the cell surfaces. The experimental results provide a new approach to directly investigate the nanoscale distribution of target protein on single clinical cancer cells.
CD20 是一种在大多数 B 细胞淋巴瘤上高度表达的膜蛋白，在临床实践中被证明是治疗 B 细胞非霍奇金淋巴瘤（NHL）的有效靶点。利妥昔单抗是一种针对 CD20 的单克隆抗体。在这项工作中，我们应用原子力显微镜（AFM）在 ROR1 荧光识别的辅助下，对来自临床 B 细胞 NHL 患者的癌细胞表面的 CD20 分子的纳米级分布进行成像，ROR1 是一种特异性的细胞表面标志物，仅在癌细胞上表达。首先，ROR1 荧光标记实验表明，ROR1 表达在 B 细胞淋巴瘤患者的癌细胞上，但在健康志愿者的正常细胞上不表达。接下来，在 ROR1 荧光的指导下，将与利妥昔单抗偶联的 AFM 探针移动到癌细胞上，对细胞形态进行成像，并检测细胞表面上的 CD20-利妥昔单抗相互作用。通过在细胞表面的局部区域（500×500nm²）获得（16×16）力曲线的阵列，构建了癌细胞上 CD20 的分布图谱。实验结果提供了一种直接研究单个临床癌细胞上靶蛋白纳米级分布的新方法。
