Post on 22-Jan-2016
description
“Isolation of rare circulating tumour cells in cancerpatients 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
• 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 Workflow1. 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