Brenner Walburgis, Benzing Frank, Gudejko-Thiel Justine, Fischer Renate, Färber Gloria, Hengstler Jan G, Seliger Barbara, Thüroff Joachim W
Department of Urology, University of Mainz, D-55131 Mainz, Germany.
Int J Oncol. 2004 Oct;25(4):1157-63.
Polarized cell movement represents an essential prerequisite for the progression and metastasis of malignant diseases. Protein kinase C (PKC) which physically associates with integrins has been implicated in the promotion of a migratory cell phenotype. In order to identify a direct link between PKC and integrins in renal cell carcinoma (RCC) the influence of PKC isoforms on integrin expression and possible consequences on proliferation and cell migration was analyzed in RCC cells. The constitutive expression of the PKC isoforms alpha, betaI, betaII, gamma, delta, epsilon, eta, theta, xi, lambda and micro was determined in the RCC cell line CCF-RC1. In addition, the influence of PKC inhibitors RO31-8220, GF109203X and GO6976 on the beta1, beta2 and beta3 integrin expression and cell proliferation of RCC cells was investigated by flow cytometry and by BrdU incorporation, respectively. Furthermore, the motility of CCF-RC1 cells was assessed through chamber chemotaxis analysis. All PKC isoforms tested were expressed in CCF-RC1 cells with the exception of PKClambda and theta. The PKC inhibitor RO31-8220 reduced beta1 integrin expression by 92% and inhibited proliferation by 42% of untreated cells, whereas cell migration remained uninfluenced by RO31-8220. GF109203X and GO6976 reduced beta1 integrin expression to approximately 50% of untreated cells. In contrast, beta2 and beta3 integrins were only weakly affected by RO31-8220, GF109203X and GO6976 treatment. The most significant influence on beta1 integrin expression was obtained by the PKC inhibitor RO31-8220. This leads to the assumption that PKCepsilon is involved in the regulation of beta1 integrin expression. Downregulation of beta1 integrins by RO31-8220 was associated with reduced proliferation, but did not influence migration. These findings provide a conceptual basis for treatment of renal cell carcinoma by interfering with tumor cell proliferation.
极化细胞运动是恶性疾病进展和转移的重要前提条件。与整合素存在物理关联的蛋白激酶C（PKC）被认为与促进迁移细胞表型有关。为了确定肾细胞癌（RCC）中PKC与整合素之间的直接联系，分析了PKC亚型对RCC细胞中整合素表达的影响以及对增殖和细胞迁移的可能影响。在RCC细胞系CCF-RC1中测定了PKC亚型α、βI、βII、γ、δ、ε、η、θ、ξ、λ和μ的组成性表达。此外，分别通过流式细胞术和BrdU掺入法研究了PKC抑制剂RO31-8220、GF109203X和GO6976对RCC细胞β1、β2和β3整合素表达及细胞增殖的影响。此外，通过小室趋化分析评估了CCF-RC1细胞的运动性。除PKCλ和θ外，所有测试的PKC亚型均在CCF-RC1细胞中表达。PKC抑制剂RO31-8220使β1整合素表达降低了92%，并使未处理细胞的增殖受到42%的抑制，而细胞迁移不受RO31-8220影响。GF109203X和GO6976使β1整合素表达降至未处理细胞的约50%。相比之下，β2和β3整合素仅受到RO31-8220、GF109203X和GO6976处理的微弱影响。PKC抑制剂RO31-8220对β1整合素表达的影响最为显著。这导致推测PKCε参与β1整合素表达的调节。RO31-8220对β1整合素的下调与增殖减少相关，但不影响迁移。这些发现为通过干扰肿瘤细胞增殖治疗肾细胞癌提供了概念基础。
