Faoro Leonardo, Cervantes Gustavo M, Ferguson Benjamin D, Seiwert Tanguy Y, Yala Soheil, Vigneswaran Wicki T, Westerhoff Maria, Tretiakova Maria S, Ferguson Mark K, Moura Glaci L, Husain Aliya N, Vokes Everett E, Salgia Ravi
Section of Hematology/Oncology, Department of Medicine, University of Chicago Pritzker School of Medicine, and University of Chicago Cancer Research Center, Chicago, IL 60637, USA.
J Carcinog. 2009;8:15. doi: 10.4103/1477-3163.57857.
Treatment of non-small cell lung cancer (NSCLC) remains a difficult task in oncology. Targeted inhibition of oncogenic proteins is promising. In this study, we evaluate the expression of MET and PKCbeta and in vitro effects of their inhibition using SU11274 and enzastaurin (LY317615.HCl) respectively.
Patient samples were analyzed by immunohistochemistry for expression of PKCbeta and MET, utilizing tissue microarrays under an IRB-approved protocol. Expression of PKCbeta and MET was evaluated in cell lines by immunoblotting. Treatment with SU1174 against MET and enzastaurin against PKCbeta was performed in H1993 and H358 cell lines, and cell proliferation and downstream signaling (phosphorylation of MET, AKT, FAK, and GSK3beta) were evaluated by immunoblotting. Statistical analysis was performed using SPSS 16.0.
Expression of MET positively correlated with lymph node metastases (p=.0004), whereas PKCbeta showed no correlation (p=0.204). MET and PKCbeta expression were also strongly correlated (p<0.001). Expression of MET was observed in 5/8 cell lines (H358, H1703, A549, H1993, H2170; absent from H522, H661, or SW1573), whereas PKCbeta expression was observed in 8/8 cell lines. Cell proliferation was significantly impaired by treatment with SU11274 and enzastaurin, and their effects were synergistic in combination (CI=0.32 and 0.09). Phosphorylation of MET, FAK, AKT, and GSK3beta were strongly inhibited with both agents in combination.
Concomitant inhibition of MET and PKCbeta significantly increased cytotoxicity in vitro against NSCLC, disrupting important downstream signaling pathways. Further evaluation in animal models is warranted.
非小细胞肺癌（NSCLC）的治疗仍是肿瘤学中的一项艰巨任务。对致癌蛋白进行靶向抑制具有前景。在本研究中，我们分别评估了MET和PKCβ的表达以及使用SU11274和恩杂他滨（LY317615.HCl）对它们进行抑制的体外效果。
在一项经机构审查委员会批准的方案下，利用组织芯片通过免疫组织化学分析患者样本中PKCβ和MET的表达。通过免疫印迹法评估细胞系中PKCβ和MET的表达。在H1993和H358细胞系中用SU1174针对MET以及用恩杂他滨针对PKCβ进行处理，并通过免疫印迹法评估细胞增殖和下游信号传导（MET、AKT、FAK和GSK3β的磷酸化）。使用SPSS 16.0进行统计分析。
MET的表达与淋巴结转移呈正相关（p = 0.0004），而PKCβ无相关性（p = 0.204）。MET和PKCβ的表达也呈强相关（p < 0.001）。在8个细胞系中的5个（H358、H1703、A549、H1993、H2170；H522、H661或SW1573中未检测到）观察到MET的表达，而在所有8个细胞系中均观察到PKCβ的表达。用SU11274和恩杂他滨处理显著损害细胞增殖，且它们的联合作用具有协同性（协同指数分别为0.32和0.09）。两种药物联合使用时，MET、FAK、AKT和GSK3β的磷酸化均受到强烈抑制。
同时抑制MET和PKCβ在体外对NSCLC的细胞毒性显著增加，破坏了重要的下游信号传导途径。有必要在动物模型中进行进一步评估。
