HIGH QUALITY CTC ISOLATION USING MICROBUBBLES FOR DOWNSTREAM MOLECULAR ANALYSIS


Year of Award:
2013
Award Type:
R33
Project Number:
CA174554
RFA Number:
RFA-CA-13-004
Technology Track:
Biospecimen Science Technologies
PI/Project Leader:
LIU, YU-TSUENG
Other PI or Project Leader:
N/A
Institution:
UNIVERSITY OF CALIFORNIA SAN DIEGO
ABSTRACT Early cancer detection and intervention are crucial for long-term survival of eitherprimary or recurrent tumors. Circulating tumor cells (CTCs) could be isolated for thediagnosis, prognosis, and treatment planning of cancer. Genetic profiling and expressionanalysis of CTC could provide additional invaluable information for accurate diagnosisand prognosis. Moreover, in vitro culture of CTC can be applied for functional analysis ofcancer cells, such as drug sensitivity test. To achieve this goal, a transformativetechnology must be able to unmistakably isolate a few cancer cells using cost-effectiveand non-invasive procedures. Under the previous R21 IMAT award, we developed a novel technology for raretumor cell isolation. Lipid shell-perfluorocarbon buoyant microbubbles (MBs) coated withanti-EpCAM antibody immediately attached to tumor cells in unfractionated blood, andisolated the cells after a quick centrifugation step (Shi et al., PLoS One, 2013). A shortvideo clip to demonstrate this technology is included in this application. In conclusion,MB technique offers unique advantages over the existing immuno-enrichmenttechnologies: (a) Short processing time can avoid RNA and protein degradation; (b)Scalability (isolation of cells from large volume sample) can help obtain large numbers ofCTCs; (c) Specificity (minimal carryover of leukocytes) can improve sensitivity andspecificity of molecular analysis; (d) Flexibility (cells are collected in a very concentratedvolume of 5-10 ¨l and could be used for cell growth, immunostaining and/or molecularanalysis. The R33 phase of this proposal is focused to further develop MB isolationmethod to achieve high purity isolation of CTCs from metastatic brain cancers forenumeration and molecular and functional analyses. We set the following specific aimsof the study: (1) Optimize MB method to achieve high speed, high purity harvesting oftumor cells spiked in 7-20ml blood sample; (2) Applications of MB isolated CTCs forPCR analysis and culturing; (3) Validate the MB method for sensitivity and specificity ofCTC enumeration from blood of metastatic brain tumor patients using CellSearch systemas a benchmark. Simple but robust CTC isolation technologies that result in high quality CTCsample for downstream analysis will have transformative impact on clinical managementof malignancies and early diagnostics of asymptomatic cancers.