Department of Chemistry, Jinan University, Tianhe District, Guangzhou, PR China.
Anal Chim Acta. 2011 Jul 4;697(1-2):83-9. doi: 10.1016/j.aca.2011.04.028. Epub 2011 Apr 23.
The cell surface glycoprotein CD44 was implicated in the progression, metastasis and apoptosis of certain human tumors. In this study, we used atomic force microscope (AFM) to monitor the effect of curcumin on human hepatocellular carcinoma (HepG2) cell surface nanoscale structure. High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with curcumin. The membrane average roughness increased (10.88 ± 4.62 nm to 129.70 ± 43.72 nm) and the expression of CD44 decreased (99.79 ± 0.16% to 75.14 ± 8.37%). Laser scanning confocal microscope (LSCM) imaging showed that CD44 molecules were located on the cell membrane. The florescence intensity in control group was weaker than that in curcumin treated cells. Most of the binding forces between CD44 antibodies and untreated HepG2 cell membrane were around 120-220 pN. After being incubated with curcumin, the major forces focused on 70-150 pN (10 μM curcumin-treated) and 50-120 pN (20 μM curcumin-treated). These results suggested that, as result of nanoscale molecular redistribution, changes of the cell surface were in response to external treatment of curcumin. The combination of AFM and LSCM could be a powerful method to detect the distribution of cell surface molecules and interactions between molecules and their ligands.
细胞表面糖蛋白 CD44 被认为与某些人类肿瘤的进展、转移和凋亡有关。在这项研究中，我们使用原子力显微镜（AFM）来监测姜黄素对人肝癌（HepG2）细胞表面纳米级结构的影响。高分辨率成像显示，细胞形态和超微结构在姜黄素处理后发生了很大变化。细胞膜平均粗糙度增加（10.88 ± 4.62nm 至 129.70 ± 43.72nm），CD44 的表达减少（99.79 ± 0.16%至 75.14 ± 8.37%）。激光共聚焦显微镜（LSCM）成像显示 CD44 分子位于细胞膜上。对照组的荧光强度弱于姜黄素处理组。未经处理的 HepG2 细胞膜与 CD44 抗体之间的结合力主要分布在 120-220pN 左右。用姜黄素孵育后，主要的力集中在 70-150pN（10μM 姜黄素处理）和 50-120pN（20μM 姜黄素处理）。这些结果表明，由于纳米级分子再分配，细胞表面的变化是对姜黄素外部处理的反应。AFM 和 LSCM 的结合可以成为一种强大的方法来检测细胞表面分子的分布以及分子与其配体之间的相互作用。
