Integrated microfluidic and imaging platform for a kinase activity radioassay to analyze minute patient cancer samples

摘要

Oncogenic kinase activity and the resulting aberrant growth and survival signaling is a common driving force of cancer. Accordingly, many successful molecularly targeted anti-cancer therapeutics are directed at inhibiting kinase activity. To assess kinase activity in minute patient samples, we have developed an immunocapture-based in vitro kinase assay on an integrated polydimethylsiloxane (PDMS) microfluidics platform that can reproducibly measure kinase activity from as few as 3,000 cells. For this platform, we adopted the standard radiometric ³²P-ATP labeled phosphate transfer assay. Implementation on a microfluidic device required us to develop methods for repeated trapping and mixing of solid-phase affinity micro beads. We also developed a solid state beta-particle camera imbedded directly below the microfluidic device for real-time quantitative detection of the signal from this and other microfluidic radio bioassays. We demonstrate that the resulting integrated device can measure ABL kinase activity from BCR-ABL positive leukemia patient samples. The low sample input requirement of the device creates new potential for direct kinase activity experimentation and diagnostics on patient blood, bone marrow, and needle biopsy samples.