EGFR/Vimentin/Folic Acid磁球检测肺癌循环肿瘤细胞初探

Preliminary Study on Detection of Circulating Tumor Cells in Lung Cancer by EGFR/Vimentin/Folic Acid Magnetic Sphere

背景与目的循环肿瘤细胞(circulating tumor cell, CTC)在肺癌的筛查及预后方面发挥着重要的作用,但较低的CTC分离效率和特异性对其临床应用有着明显的制约,本研究旨在探讨非小细胞肺癌(non-small cell lung cancer, NSCLC)患者CTC的新型高效分离方法,以期达到对NSCLC的早期诊断的目的。方法采用薄膜法制备表皮生长因子受体(epidermal growth factor receptor, EGFR)、波形蛋白(Vimentin)和叶酸(folic acid, FA)三种免疫脂质磁球,表征后通过细胞系进行分选方案的探索,构建对NSCLC CTC的最优分选方案,初步研究了其在临床上的应用价值。结果 EGFR、Vimentin和FA磁球磁球单独和联合使用对肺癌细胞株的平均捕获效率分别为78.0%、79.0%、82.0%和91.0%;在60例肺癌患者中,以每7.5 mL血液2个CTC为cutoff值,EGFR、Vimentin、FA磁球单独和联合使用阳性率分别为65.0%、33.3%、93.3%和100.0%,同时发现联合使用三种磁球检出的CTC数量与临床分期具有相关性(P<0.05)。结论联合使用三种磁球可以分离EGFR+、Vimentin+和FA+表达且形态完整的CTC,有利于的CTC相关下游分析,本研究提供了一种提高NSCLC CTC捕获效率的新方法,且验证了捕获的CTC计数方法可用于肺癌的辅助诊断。

Background and Objective Circulating tumor cells(CTC) play an important role in the screening and prognosis of lung cancer, but the low efficiency and specificity of CTC isolation obviously restrict its clinical application. The purpose of this study is to explore a new and efficient isolation method of CTC in patients with non-small cell lung cancer(NSCLC) in order to achieve the purpose of early diagnosis of NSCLC. Methods Three kinds of immunolipid magnetic spheres of epidermal growth factor receptor(EGFR), vimentin and folic acid(FA) were prepared by thin film method. After characterization, the sorting scheme of cell line was explored, the optimal sorting scheme of NSCLC CTC was constructed, and its clinical application value was studied. Results The average capture efficiency of EGFR, Vimentin and FA magnetic spheres used alone and in combination to lung cancer cell lines was 78%, 79%, 82% and 91%, respectively. In 60 patients with lung cancer, using 2 CTC per 7.5 mL blood as cutoff value, the positive rates of EGFR, Vimentin and FA magnets used alone and in combination were 65.0%, 33.3%, 93.3% and 100%, respectively. It was also found that the number of CTC detected by combined use of the three magnetic spheres was correlated with clinical stages(P<0.05). Conclusion The combination of three kinds of magnetic spheres can separate EGFR+, Vimentin+, FA+ expressed CTC, which is beneficial to the downstream analysis of CTC correlation. This study provides a new method to improve the efficiency of NSCLC CTC capture, and verifies that the captured CTC counting method can be used in the auxiliary diagnosis of lung cancer.