Grzesiak John J, Smith Kathy C, Chalberg Cheryl, Burton Douglas W, Deftos Leonard J, Bouvet Michael
Department of Surgery, University of California, San Diego and Veterans Affairs, San Diego Healthcare System, San Diego, CA 92161, USA.
Int J Gastrointest Cancer. 2005;36(3):131-46. doi: 10.1385/IJGC:36:3:131.
We have shown in FG pancreatic cancer cells that alpha2beta1 integrin-mediated type I collagen adhesion decreases parathyroid hormone-related protein (PTHrP), interleukin-6 (IL-6), and interleukin-8 (IL-8) expression, decreases the localization of E-cadherin and beta-catenin in cell-cell contacts, increases cell migration, and increases glycogen synthase kinase 3 (GSK3) and protein kinase B (PKB/Akt) phosphorylation states relative to alpha5beta1 integrin-mediated fibronectin (Fn) adhesion.
To extend our observations in FG cells to other pancreatic cancer cell lines, and to determine whether E-cadherin-mediated cell-cell adhesion and its downstream effectors were functionally involved in the ECM-mediated regulation of PTHrP, IL-6, and IL-8.
We used standard biochemical techniques to determine ECM-specific differences in E-cadherin and beta-catenin localization, GSK3 and PKB/Akt phosphorylation, haptokinetic cell migration, and cytokine expression in pancreatic cancer cells. We also conducted functional studies using pharmacological inhibitors for GSK3 and PKB/Akt, as well as elevated Mg2+/Ca2+ ratios similar to pancreatic juice, and examined their effects on cytokine expression.
Differences in E-cadherin and beta-catenin localization along with GSK3 and PKB/Akt phosphorylation occur in multiple pancreatic cancer cell lines, resulting in differences in ECM-mediated haptokinesis and cytokine expression that are generally consistent with previous observations in FG cells. Our functional studies also suggest that E-cadherin-mediated cell-cell adhesion and downstream effectors are involved in PTHrP, IL-6, and IL-8 expression.
These data indicate that alpha2beta1 integrin-mediated type I collagen adhesion disrupts cell-cell adhesion architecture, resulting in increased migration and decreased PTHrP, IL-6, and IL-8 expression in pancreatic cancer cells.
我们已经在FG胰腺癌细胞中证实，α2β1整合素介导的I型胶原黏附可降低甲状旁腺激素相关蛋白（PTHrP）、白细胞介素-6（IL-6）和白细胞介素-8（IL-8）的表达，减少E-钙黏蛋白和β-连环蛋白在细胞间接触部位的定位，增加细胞迁移，并相对于α5β1整合素介导的纤连蛋白（Fn）黏附增加糖原合酶激酶3（GSK3）和蛋白激酶B（PKB/Akt）的磷酸化状态。
将我们在FG细胞中的观察结果扩展到其他胰腺癌细胞系，并确定E-钙黏蛋白介导的细胞间黏附及其下游效应分子是否在细胞外基质（ECM）介导的PTHrP、IL-6和IL-8调节中发挥功能作用。
我们使用标准生化技术来确定胰腺癌细胞中E-钙黏蛋白和β-连环蛋白定位、GSK3和PKB/Akt磷酸化、触觉运动细胞迁移以及细胞因子表达方面的ECM特异性差异。我们还使用GSK3和PKB/Akt的药理学抑制剂以及类似于胰液的升高的Mg2+/Ca2+比值进行功能研究，并检查它们对细胞因子表达的影响。
多种胰腺癌细胞系中存在E-钙黏蛋白和β-连环蛋白定位以及GSK3和PKB/Akt磷酸化的差异，导致ECM介导的触觉运动和细胞因子表达存在差异，这与之前在FG细胞中的观察结果总体一致。我们的功能研究还表明，E-钙黏蛋白介导的细胞间黏附及其下游效应分子参与了PTHrP、IL-6和IL-8的表达。
这些数据表明，α2β1整合素介导的I型胶原黏附破坏了细胞间黏附结构，导致胰腺癌细胞迁移增加以及PTHrP、IL-6和IL-8表达降低。
