Isolation of circulating tumor cells (CTC) and peritoneal tumor cells (PTC) by cytology-based filtration platform and its application to monitoring therapeutic effect

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K10524
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Digestive surgery
• Research Institution: Aichi Cancer Center Research Institute
• Principal Investigator: ITO Seiji 愛知県がんセンター(研究所), 分子腫瘍学分野, 研究員 (50393129)
• Research Collaborator: ITO yuichi ; NAKANISHI hayao
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 血液中循環がん細胞(CTC) / 腹腔洗浄液中がん細胞(PTC) / 細胞診 / フィルター型デバイス / 自動分離装置 / 薬物治療 / Liquid biopsy

Outline of Final Research Achievements

In the present study, we newly developed a cytology-based, automated CTC/PTC isolation device for liquid biopsy. This platform consists of three steps; enrichment of CTCs with filter, transfer of CTCs to glass slide and staining with Pap and immunocytochemistry. CTC (PTC) are identified under light microscopy as cytokeratin (CEA)-positive cells with atypical morphology. Some genetic analysis such as FISH is also possible. Pilot clinical study showed that CTC number was higher in drainage vein blood (DVB) than peripheral blood, suggesting that CTCs in DVB are potential source for genetic analysis. Furthermore, using gastric cancer mouse CTC model, we demonstrated transient increase in CTC number early after T-DM1 therapy, suggesting mobilization of CTCs in rapid response to drug therapy. These results indicate that current CTC (PTC) detection platform would be a powerful diagnostic tool for early detection of metastasis and monitoring drug sensitivity in clinical setting.

Free Research Field

消化器外科学

Academic Significance and Societal Importance of the Research Achievements

本研究でCTCの同定を迅速、低コストに光学顕微鏡下で行うことが可能なデバイスを新たに開発し、市中病院でもCTCの測定をルチーン検査として行うことができる可能性が示唆された。デバイスのFilter径を大きくすることにより従来の洗浄細胞診に比べ高感度かつ半定量的なPTCの検出が可能となった。またDVBを用いることにより一定数以上のCTCの回収が可能となりCTCの遺伝子解析の可能性が示唆された。一方、ヒト胃癌のCTCマウスモデルを確立し、T-DM1治療後早期に一過性にCTC数が増加すること、すなわちCTCが動員される可能性を見出した。CTCモニターによる抗がん剤感受性評価の可能性が示唆された。