Download Isolation of rare circulating tumour cells in cancer

“Isolation of rare circulating
tumour cells in cancer
patients by microchip
technology”
Nagrath et al.
Nature 2007
Peter Bojo
Big Picture
• Potential uses of CTCs
– Choice of therapy
– Monitoring of therapy
– Explaining the biology of metastasis
• Microchip is one of many CTC
technologies
– Immunomagnetic beads
– Total RNA qPCR
Microchip Design
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Blood pumped through forest of posts
~80,000 posts on a ~10cmX10cm chip
EpCAM antibodies on posts
Testing with cancer cell spiked solutions
determines:
– Flow rate ~1mL/hr
– High capture efficiency even for low EpCAM
expression levels ~60%
– Identical capture efficiency for whole blood and lysed
blood
Microchip Workflow
1. Take whole blood sample,
flow through optimized chip
2. Stain with DAPI, cytokeratin,
and CD45 antibodies. 47% purity
3. Analyze CTC sensitivity, viability,
and predictive ability
Cancer Patient CTC Experiment
• NSCLC, prostate, pancreatic, breast, and
colon cancer samples.
• Metastatic and non-metastatic prostate
cancer samples.
• Isolated between 5 and 1300 CTCs per
patient in 115/116 cases.
• 0 CTCs in healthy samples
• High sensitivity
Predictive Ability for Cancer Treatment
Conclusions
• Microchip is a competitive CTC enrichment
technology
• Uses unprocessed blood
• High purity of isolated cells:
47%
• High sensitivity:
99%
• Capture efficiency:
~60%
• High cell viability:
98%
• Further Study warranted for:
– CTC count and tumor size correlation
– Comparable numbers of CTCs in localized and
metastatic cancers