Abstract 3080: Comparison of CellSearch with polymeric microfluidic devices for CTC isolation using EpCAM-negative tumor cell lines of malignant pleural mesothelioma

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Background. The CellSearch system is the most commonly used technique approved by the FDA to isolate and quantify circulation tumor cells (CTCs). However, in this system, the efficiency of CTC isolation is influenced by the epithelial cell adhesion molecule (EpCAM). Therefore, it is difficult to isolate CTCs in the setting of the epithelial to mesenchymal transition (EMT), malignant pleural mesothelioma and so on. We developed polymeric microfluidic devices for CTC isolation (CTC-chip) and compared the efficacy of CellSearch with CTC-chip using EpCAM-negative tumor cell lines of malignant pleural mesothelioma. Methods. In order to evaluate the accuracy of the number of CTCs, we used PBS samples and peripheral blood samples (blood samples) collected from healthy donors to which spiking the tumor cell lines ACC-MESO1 and ACC-MESO4. Both tumor cell lines (obtained from ATCC) were derived from malignant pleural mesothelioma, positive for mesothelin and podoplanin and negative for EpCAM. The recovery rate was evaluated using two methods. CellSearch was performed according to the normal method, while CTC-chip was performed using a two coating pattern with anti-mesothelin antibody (chip1) and anti-podoplanin antibody (chip2). Results. In the PBS samples, the recovery rate of captured ACC-MESO1 was 8.6%/98%/99% (CellSearch/chip 1/chip 2), while those of ACC-MESO4 was 21.1%/97%/99%, respectively. In the blood samples, the recovery rate of captured ACC-MESO1 was 1.2%/6.2%/13.3% (CellSearch/chip 1/chip 2), while that of ACC-MESO4 was 6.0%/3.7%/11.6%, respectively. Conclusions. Our experiments showed that the recovery rate of each sample was higher using CTC-chip than that obtained with CellSearch. Moreover, CTC-chip coated anti-podoplanin antibody exhibited a higher recovery rate than coated anti-mesothelin antibody. Future studies using experiments of CTC isolation in cancer patients with malignant pleural mesothelioma are thus required. Citation Format: Yasuhiro Chikaishi, Tomoko So, Masaru Takenaka, Soichi Oka, Ayako Hirai, Takashi Iwanami, Hidehiko Shimokawa, Kazue Yoneda, Yoshika Nagata, Hidetaka Uramoto, Takeshi Ohnaga, Fumihiro Tanaka. Comparison of CellSearch with polymeric microfluidic devices for CTC isolation using EpCAM-negative tumor cell lines of malignant pleural mesothelioma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3080. doi:10.1158/1538-7445.AM2014-3080