Cancer Letters, 2010, 292(1):54-63.

Combined cetuximab and genistein treatment shows additive anti-cancer effect on oral squamous cell carcinoma

Sung-Jin Park, Yu-Kyoung Kim, Ju-Yong Park, et al

Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul, South Korea; Dental Research Institute, Seoul National University, Seoul, South Korea; Oral Cancer Clinic, National Cancer Center, Seoul, South Korea

The purpose of this study was to evaluate the potency of EGFR pathway inhibition achieved by combining cetuximab, an anti-EGFR monoclonal antibody, and genistein, a tyrosine kinase inhibitor, which target extracellular and intracellular domains of the receptor, respectively, in oral squamous cell carcinoma (OSCC) in vitro and in vivo. Two OSCC cell lines, HSC3 and KB, were treated with cetuximab (C, 0-400ug/ml), genistein (G, 0-80uM), or a combination of both at a range of concentrations. Downstream protein expression of EGFR, p-EGFR, and p-Akt were evaluated by Western blot. Cell proliferation and apoptosis indices were calculated to assess anti-cancer effects in vitro. The in vivo effects of cetuximab and genistein on tumor cell growth were examined using an OSCC xenografted nude mouse model and immunohistochemical analyses of proliferation (PCNA) and microvessel density (CD31). Treatment of cells with dual anti-EGFR agents reduced the expressions of p-EGFR, and p-Akt in HSC3 cell line, but there was no significant difference in downregulation between cetuximab alone and in combination with genistein in KB cells. Both HSC3 and KB cells showed a dose-dependent decrease in cell proliferation significantly with single agent treatment and combination (p<0.05). In low concentration, combined cetuximab and genistein therapy resulted in additive growth inhibition and more apoptosis compared to that achieved with single-agent exposure in both cell lines. A combination of cetuximab and genistein significantly inhibited tumor growth and caused a substantial growth delay in in vivo models of both cell lines while each single-agent exposure caused no delay of tumor growth. Immunohistochemical staining with PCNA revealed that the group receiving combined cetuximab and genistein exhibited the lowest number of proliferating cells and microvessel density (p<0.05). Combined therapy with genistein and cetuximab can add the potency of EGFR signaling inhibition. Because not all OSCC cell types appear to respond uniformly, however, selective targeting of distinct molecular pathways is required for effective clinical response.

爱尔兰《癌症快报》2010年6月

西妥昔单抗和金雀异黄素的联合治疗对口腔鳞状细胞癌表现出增强的抗肿瘤效应

朴松金，金宇京，朴玉勇等

韩国汉城国立大学牙医学院口腔颌面外科系，韩国首尔国立大学牙科研究所，韩国首尔国立癌症中心口腔癌临床

本研究的目的在于评估西妥昔单抗（一种抗 EGFR 单克隆抗体）和金雀异黄素（一种酪氨酸激酶抑制剂）针对口腔鳞状细胞癌 (OSCC) 体内和体外细胞内部与外部受体联合起来共同抑制 EGFR 通路的效力。两种口腔鳞状细胞癌的细胞系，HSC3 和 KB，被西妥昔单抗 (C，0-400ug/ml)，金雀异黄素 （G，0-80uM），或者在一定浓度范围内两者共同来处理。EGFR，p-EGFR 和 p-Akt的下游蛋白表达可以通过免疫印迹法进行评价。细胞增殖和凋亡指数被计算用来评估体外抗肿瘤作用。使用口腔鳞状细胞癌裸鼠移植瘤模型和免疫组织化学法对扩散 (PCNA) 和微血管密度 (CD31) 的分析，考察了西妥昔单抗和金雀异黄素对肿瘤细胞生长的体内影响。用两种抗 EGFR 的抗体来处理细胞，降低了p-EGFR 和p-Akt在 HSC3 细胞系的表达，但是在KB 细胞中单独用西妥昔单抗和结合金雀异黄素使用导致下调两者没有显著差异。当使用单独试剂和组合 试剂使细胞大幅度增殖时，HSC3 和 KB 细胞都表现出对剂量依赖性的降低(p < 0.05)。在浓度较低时，西妥昔单抗与染料木黄酮的联合疗法导致增强的生长抑制作用和相比于单一试剂处理两种细胞系更多的细胞凋亡。虽然在单独使用一种试剂时没有引起肿瘤生长的延迟，西妥昔单抗和金雀异黄素的联合使用明显抑制了肿瘤的生长，并且导致两种细胞系体内模型的大幅度生长延迟。用PCNA进行的免疫组织化学染色揭示了接受西妥昔单抗和金雀异黄素联合治疗的实验组表现出最低数目的细胞增殖和微血管密度 (p < 0.05)。金雀异黄素与西妥昔单抗的联合疗法可以增强EGFR信号抑制的作用。因为并不是所有OSCC的类型看起来好像反应一致，然而，选择性针对不同的分子途径需要有效的临床反应。