Combined cell surface carbonic anhydrase 9 and CD147 antigens enable high-efficiency capture of circulating tumor cells in clear cell renal cell carcinoma patients

Circulating tumor cells (CTCs) have emerged as promising tools for noninvasive cancer detection and prognosis. Most conventional approaches for capturing CTCs use an EpCAM-based enrichment strategy, which does not work well in cancers that show low or no expression of EpCAM, such as renal cell carcinoma (RCC). In this study, we developed a new set of cell surface markers including CA9 and CD147 as alternative CTC-capture antigens specifically designed for RCC patients. We showed that the expression of both CA9 and CD147 was prevalent in a RCC patient cohort (n=70) by immunohistochemical analysis, with both molecules in combination covering 97.1% of cases. The NanoVelcro platform combined with CA9-/CD147-capture antibodies demonstrated significantly higher efficiency for capturing both CTC-mimicking renal cancer cells and RCC CTCs in peripheral blood, compared to the conventional EpCAM-based method. Using immunofluorescence cytological validation at the single-cell level, we were able to identify bona fide CTCs in RCC patient blood following the well-accepted criteria in our CTC-capture system. We further demonstrated a significant association of CTC numbers as well as the CTC expression status of Vimentin, a mesenchymal marker, with disease progression, including pathologic features and clinical staging. These results provide new insights into developing novel, effective targets/approaches for capturing CTCs, making CTCs a valuable tool for improved cancer detection, prognosis and treatment in RCC.

Oncotarget. 2016 Aug 01 [Epub ahead of print]

Shijie Liu, Zuhong Tian, Lei Zhang, Shuang Hou, Sijun Hu, Junshen Wu, Yuming Jing, Huimin Sun, Fei Yu, Libo Zhao, Ruoxiang Wang, Hsian-Rong Tseng, Haiyen E Zhau, Leland W K Chung, Kaichun Wu, Hao Wang, Jason Boyang Wu, Yongzhan Nie, Chen Shao

Department of Urology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., State Key Laboratory of Cancer Biology & Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., Department of Epidemiology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging, California Nanosystems Institute, University of California, Los Angeles, CA 90095, USA., State Key Laboratory of Cancer Biology & Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., Department of Urology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., Department of Urology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., Department of Urology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., Department of Urology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China., Uro-Oncology Research Program, Department of Medicine, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA., Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging, California Nanosystems Institute, University of California, Los Angeles, CA 90095, USA., Uro-Oncology Research Program, Department of Medicine, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA., Uro-Oncology Research Program, Department of Medicine, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA., State Key Laboratory of Cancer Biology & Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Nanotechnology, Beijing 100190, China., Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane, WA 99202, USA., State Key Laboratory of Cancer Biology & Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China., Department of Urology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China.