From the Department of Surgery, VA San Diego Healthcare System and the University of California, San Diego, San Diego, CA 92161, USA.
Pancreas. 2010 Aug;39(6):904-12. doi: 10.1097/MPA.0b013e3181ce60a3.
We previously showed that divalent cations regulate alpha2beta1 integrin-mediated pancreatic cancer cell interactions with type I collagen in 2 dimensions (2D), including cell adhesion, migration, and proliferation. Presently, we examined divalent cation-dependent alpha2beta1 integrin-mediated pancreatic cancer cell adhesion and proliferation on type I collagen in a novel 3D in vitro model.
Cell attachment, proliferation, and antibody inhibition assays on type I collagen in both 2D and 3D, and microscopy and immunoblotting were used for these studies.
As in 2D, cell attachment on type I collagen in 3D is Mg-dependent and inhibited by Ca. Proliferation in 3D is also Mg-dependent, but maximal when Mg is present at concentrations that promote maximal cell adhesion and Ca is present at concentrations less than Mg. Immunoblotting studies demonstrate that the divalent cation-dependent changes in cell-cell adhesion observed on type I collagen in both 2D and 3D are associated with the changes in E-cadherin and beta-catenin expression. Antibody inhibition assays indicate further that the alpha2beta1 integrin specifically mediates proliferation on type I collagen in 3D under altered divalent cation conditions.
Divalent cation shifts could activate alpha2beta1 integrin-mediated malignancy in the type I collagen-rich 3D tumor microenvironment of pancreatic cancer.
我们之前的研究表明，二价阳离子可调节α2β1 整合素介导的胰腺癌细胞与 I 型胶原在二维（2D）水平上的相互作用，包括细胞黏附、迁移和增殖。目前，我们在一种新型的 3D 体外模型中研究了二价阳离子依赖性α2β1 整合素介导的胰腺癌细胞在 I 型胶原上的黏附和增殖。
在 2D 和 3D 条件下，使用细胞黏附、增殖和抗体抑制实验以及显微镜和免疫印迹技术进行了这些研究。
与 2D 条件一样，3D 条件下细胞在 I 型胶原上的黏附也依赖于 Mg，且被 Ca 抑制。3D 条件下的增殖也依赖于 Mg，但在促进最大细胞黏附的 Mg 浓度和低于 Mg 的 Ca 浓度存在时达到最大值。免疫印迹研究表明，在 2D 和 3D 的 I 型胶原上观察到的细胞间黏附的二价阳离子依赖性变化与 E-钙黏蛋白和β-连环蛋白表达的变化有关。抗体抑制实验进一步表明，在改变的二价阳离子条件下，α2β1 整合素特异性介导 3D 中 I 型胶原上的增殖。
二价阳离子变化可能会激活富含 I 型胶原的胰腺癌细胞肿瘤微环境中的α2β1 整合素介导的恶性行为。
