Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.
Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain. Statistics Department. University of Barcelona (UB), Barcelona, Spain.
Clin Cancer Res. 2014 Dec 15;20(24):6346-56. doi: 10.1158/1078-0432.CCR-14-0361. Epub 2014 Oct 16.
The lack of secreted biomarkers measurable by noninvasive tests hampers the development of effective targeted therapies against cancer. Our hypothesis is that cetuximab (an anti-EGFR mAb) induces a specific secretome in colorectal cancer cells that could be exploited for biomarker discovery.
Considering the strong correlation between mutated KRAS and a lack of response to cetuximab therapy, we addressed whether performing secretome-based proteomics on isogenic colorectal cancer cells sharing the KRAS mutations found on patients would yield candidate-secreted biomarkers useful in the clinical setting. Because 2D culture did not optimally model the sensitivity/resistance to cetuximab observed in colorectal cancer patients, we moved to 3D spheroids, developing a methodology for both cell-based assays and quantitative proteomics.
A large comparative quantitative proteomic analysis of the 3D secretomes of colorectal cancer isogenic cells treated with cetuximab uncovered an EGFR pathway-centric secretome found only when cells grow in 3D. The validation of the secretome findings in plasma of colorectal cancer patients, suggests that phosphorylated-EGFR (pEGFR) is a candidate-secreted biomarker of response to cetuximab.
We have proved that 3D spheroids from colorectal cancer cells generate secretomes with a drug-sensitivity profile that correlates well with patients with colorectal cancer, illustrating molecular connections between intracellular and extracellular signaling. Furthermore, we show how the secretion of pEGFR is associated with the sensitivity of colorectal cancer cells to cetuximab and the response of patients with colorectal cancer to the drug. Our work could allow the noninvasive monitoring of anti-EGFR treatment in patients with colorectal cancer.
缺乏可通过非侵入性测试测量的分泌生物标志物，阻碍了针对癌症的有效靶向治疗的发展。我们的假设是，西妥昔单抗（一种抗 EGFR mAb）诱导结直肠癌细胞产生一种特异性的分泌组，可用于发现生物标志物。
鉴于突变型 KRAS 与对西妥昔单抗治疗反应缺乏之间的强烈相关性，我们研究了对具有患者中发现的 KRAS 突变的同基因结直肠癌细胞进行基于分泌组的蛋白质组学分析是否会产生在临床环境中有用的候选分泌生物标志物。由于 2D 培养不能最佳地模拟结直肠癌细胞对西妥昔单抗的敏感性/耐药性，我们转向 3D 球体，开发了用于细胞基础测定和定量蛋白质组学的方法。
对用西妥昔单抗处理的结直肠癌细胞的 3D 分泌组进行的大型比较定量蛋白质组学分析揭示了一种仅在细胞 3D 生长时才发现的 EGFR 通路为中心的分泌组。在结直肠癌患者的血浆中验证分泌组发现表明，磷酸化-EGFR（pEGFR）是对西妥昔单抗反应的候选分泌生物标志物。
我们已经证明，来自结直肠癌细胞的 3D 球体产生的分泌组具有与结直肠癌患者相关性良好的药物敏感性谱，说明了细胞内和细胞外信号之间的分子联系。此外，我们展示了 pEGFR 的分泌如何与结直肠癌细胞对西妥昔单抗的敏感性以及结直肠癌患者对该药物的反应相关。我们的工作可以允许对结直肠癌患者的抗 EGFR 治疗进行非侵入性监测。
