Heindl Stefan, Eggenstein Evelyn, Keller Simone, Kneissl Julia, Keller Gisela, Mutze Kathrin, Rauser Sandra, Gasteiger Georg, Drexler Ingo, Hapfelmeier Alexander, Höfler Heinz, Luber Birgit
Institut für Allgemeine Pathologie und Pathologische Anatomie, Technische Universität München, Klinikum rechts der Isar, Trogerstr. 18, 81675, Munich, Germany.
J Cancer Res Clin Oncol. 2012 May;138(5):843-58. doi: 10.1007/s00432-011-1128-4.
The therapeutic activity of the epidermal growth factor receptor (EGFR)-directed monoclonal antibody cetuximab in gastric cancer is currently being investigated. Reliable biomarkers for the identification of patients who are likely to benefit from the treatment are not available. The aim of the study was to examine the drug sensitivity of five gastric cancer cell lines towards cetuximab as a single agent and to establish predictive markers for chemosensitivity in this cell culture model. The effect of a combination of cetuximab with chemotherapy was compared between a sensitive and a nonsensitive cell line.
EGFR expression, activation and localisation, the presence and subcellular localisation of the cell adhesion molecule E-cadherin as well as MET activation were examined by Western blot analysis, flow cytometry and immunofluorescence staining. Cells were treated with varying concentrations of cetuximab and cisplatin and 5-fluorouracil in tumour-relevant concentrations. The biological endpoint was cell viability, which was measured by XTT cell proliferation assay. Response to treatment was evaluated using statistical methods.
We assessed the activity of cetuximab in five gastric cancer cell lines (AGS, KATOIII, MKN1, MKN28 and MKN45). The viability of two cell lines, MKN1 and MKN28, was significantly reduced by cetuximab treatment. High EGFR expression and low levels of receptor activation were associated with cetuximab responsiveness. MET activation as well as mutations of KRAS and CDH1 (gene encoding E-cadherin) was associated with cetuximab resistance.
These data indicate that our examinations may be clinically relevant, and the candidate markers should therefore be tested in clinical studies.
目前正在研究表皮生长因子受体（EGFR）导向的单克隆抗体西妥昔单抗在胃癌中的治疗活性。目前尚无可靠的生物标志物来识别可能从该治疗中获益的患者。本研究的目的是检测5种胃癌细胞系对西妥昔单抗单药的药物敏感性，并在该细胞培养模型中建立化疗敏感性的预测标志物。比较了西妥昔单抗与化疗联合应用在敏感和不敏感细胞系中的效果。
通过蛋白质免疫印迹分析、流式细胞术和免疫荧光染色检测EGFR表达、激活和定位、细胞粘附分子E-钙粘蛋白的存在及亚细胞定位以及MET激活情况。用与肿瘤相关浓度的不同浓度西妥昔单抗、顺铂和5-氟尿嘧啶处理细胞。生物学终点是细胞活力，通过XTT细胞增殖试验测定。使用统计方法评估治疗反应。
我们评估了西妥昔单抗在5种胃癌细胞系（AGS、KATOIII、MKN1、MKN28和MKN45）中的活性。西妥昔单抗处理显著降低了两种细胞系MKN1和MKN28的活力。高EGFR表达和低水平的受体激活与西妥昔单抗反应性相关。MET激活以及KRAS和CDH1（编码E-钙粘蛋白的基因）突变与西妥昔单抗耐药相关。
这些数据表明我们的检测可能具有临床相关性，因此候选标志物应在临床研究中进行测试。
