蛋白质组学分析鉴定原发肿瘤中的生物标志物，以预测肝转移新辅助化疗的反应。

Proteomic analysis to identify biomarkers in the primary tumour that predict response to neoadjuvant chemotherapy in liver metastases.

机构信息

Institute of Translational Medicine, University of Liverpool, Liverpool, UK.

出版信息

Lancet. 2015 Feb 26;385 Suppl 1:S95. doi: 10.1016/S0140-6736(15)60410-X.

DOI:10.1016/S0140-6736(15)60410-X

PMID:26312918

Abstract

BACKGROUND

Colorectal cancer is the fourth commonest cancer in the UK, and the second commonest cause of cancer-related death. A knowledge of the biological phenotype of colorectal liver metastases would be invaluable to inform clinical decision making; however, deriving this information from the metastatic lesions is not feasible until after resection. We aimed to use proteomic analysis to identify biomarkers in the primary tumour that predict response to neoadjuvant chemotherapy in liver metastases.

METHODS

Fresh tissue from both primary colorectal tumour and liver metastases from 17 patients was subjected to proteomic analysis using isobaric tagging for relative quantification. Data were analysed with Protein Pilot (Ab Sciex, Framingham, MA, USA), with stratification of patients into those showing low or high response to chemotherapy permitting the identification of potential predictive biomarkers. These markers were subsequently validated by immunohistochemistry on a tissue microarray of 63 patients.

FINDINGS

We identified 5768 discrete proteins. Five of them predicted histopathological response to fluorouracil-based chemotherapy regimens, of which the FAD binding protein NQO1 was subsequently validated by immunohistochemistry. When compared with the chemotherapeutic agent alone, knockdown of the corresponding gene with small interfering RNA decreased cell viability when co-incubated with fluorouracil (77·1% vs 46·6%, p=0·037) and irinotecan (41·7% vs 24·4%, p=0·006). Similar results were also seen after inhibition of protein activity by pretreating cells with dicoumarol.

INTERPRETATION

These results show that proteomic sequencing of matched metastatic colorectal cancer samples is feasible, with high protein coverage. The high degree of similarity between the primary and secondary proteomes suggests that primary tissue is predictive of the metastatic phenotype. NQO1 expression in the primary tumour predicts response to neoadjuvant chemotherapy in the liver metastases, and inhibition of this protein at both genetic and functional levels improves chemosensitivity.

FUNDING

Cancer Research UK.

摘要

背景

结直肠癌是英国第四大常见癌症，也是癌症相关死亡的第二大常见原因。了解结直肠肝转移的生物学表型对于指导临床决策将是非常有价值的；然而，在切除之前，从转移灶中获取这些信息是不可行的。我们旨在使用蛋白质组学分析来鉴定原发性肿瘤中的生物标志物，以预测肝转移对新辅助化疗的反应。

方法

对 17 名患者的原发性结直肠肿瘤和肝转移灶的新鲜组织进行同位素质谱标记相对定量蛋白质组学分析。使用 Protein Pilot（Ab Sciex，马萨诸塞州弗雷明汉）进行数据分析，对患者进行分层，分为对化疗反应低或高的患者，以确定潜在的预测生物标志物。随后在 63 例患者的组织微阵列上通过免疫组织化学法对这些标志物进行验证。

发现

我们鉴定出 5768 个离散蛋白。其中 5 个蛋白可预测基于氟尿嘧啶的化疗方案的组织病理学反应，其中 FAD 结合蛋白 NQO1 随后通过免疫组织化学法得到验证。与单独使用化疗药物相比，用小干扰 RNA 敲低相应基因与氟尿嘧啶（77.1%对 46.6%，p=0.037）和伊立替康（41.7%对 24.4%，p=0.006）共孵育时降低了细胞活力。在用双香豆素预处理细胞抑制蛋白活性后也观察到类似的结果。