Arias-Pinilla Gustavo A, Dalgleish Angus G, Mudan Satvinder, Bagwan Izhar, Walker Anthony J, Modjtahedi Helmout
School of Life Sciences, Pharmacy and Chemistry, Kingston University London, Kingston-upon-Thames, Surrey, UK.
Department of Cellular and Molecular Medicine, St George's University of London, London, UK.
Oncotarget. 2018 Apr 13;9(28):19994-20007. doi: 10.18632/oncotarget.25017.
Pancreatic cancer is one of the most aggressive and lethal types of cancer, and more effective therapeutic agents are urgently needed. Overexpressed cell surface antigens are ideal targets for therapy with monoclonal antibody (mAb)-based drugs, but none have been approved for the treatment of pancreatic cancer. Here, we report development of two novel mouse mAbs, KU42.33C and KU43.13A, against the human pancreatic cancer cell line BxPC-3. Using ELISA, flow cytometry, competitive assay and immunoprecipitation followed by mass spectrometry, we discovered that these two mAbs target two distinct epitopes on the external domain of CD109 that are overexpressed by varying amounts in human pancreatic cancer cell lines. Treatment with these two naked antibodies alone did not affect tumour cell growth or migration . Of the two mAbs, only KU42.33C was useful in determining the expression of CD109 in tumour cells by Western blot and immunohistochemistry. Interestingly, immunohistochemistry of human pancreatic carcinoma tissue arrays with mAb KU42.33C showed that 94% of the 65 human pancreatic adenocarcinoma cases were CD109 positive, with no expression in normal pancreatic tissues. Our results suggest that these two novel mAbs are excellent tools for determining the expression level of CD109 in the tumour specimens and sera of patients with a wide range of cancers, in particular pancreatic cancer, and for investigating its diagnostic, prognostic and predictive value. Further research is warranted and should aim to unravel the therapeutic potential of the humanised forms or conjugated versions of such antibodies in patients whose tumours overexpress CD109 antigen.
胰腺癌是最具侵袭性和致命性的癌症类型之一，因此迫切需要更有效的治疗药物。过表达的细胞表面抗原是基于单克隆抗体（mAb）的药物治疗的理想靶点，但目前尚无获批用于治疗胰腺癌的此类药物。在此，我们报告了两种新型小鼠单克隆抗体KU42.33C和KU43.13A的研发情况，它们针对人胰腺癌细胞系BxPC-3。通过酶联免疫吸附测定（ELISA）、流式细胞术、竞争试验和免疫沉淀后质谱分析，我们发现这两种单克隆抗体靶向CD109胞外域上两个不同的表位，在人胰腺癌细胞系中这两个表位的表达量有所不同。单独使用这两种裸抗体进行治疗不会影响肿瘤细胞的生长或迁移。在这两种单克隆抗体中，只有KU42.33C可用于通过蛋白质免疫印迹法（Western blot）和免疫组织化学法测定肿瘤细胞中CD109的表达。有趣的是，用单克隆抗体KU42.33C对人胰腺癌组织芯片进行免疫组织化学分析显示，在65例人胰腺腺癌病例中，94%的病例CD109呈阳性，而在正常胰腺组织中无表达。我们的结果表明，这两种新型单克隆抗体是用于确定广泛癌症患者，尤其是胰腺癌患者肿瘤标本和血清中CD109表达水平，以及研究其诊断、预后和预测价值的优良工具。有必要进行进一步研究，其目标应是揭示此类抗体的人源化形式或偶联形式对肿瘤过表达CD109抗原患者的治疗潜力。
