Abstract

Click Chip Enables Non-Invasive mRNA Analysis in Circulating Tumor Cells

Yazhen Zhu, Assistant Project Scientist, David Geffen School of Medicine at UCLA

Recent research focus in the field of circulating tumor cells (CTCs) has moved beyond the simple capture or enumeration of CTCs and gravitated towards approaches that allow for in-depth molecular analysis. CTCs house intact mRNA, providing more reliable gene signatures in tumors non-invasively. Exploring the use of CTC-derived mRNA offers a non-invasive diagnostic solution for understanding underlying tumor biology, guiding treatment intervention, and monitoring disease progression. Recently, we demonstrated a new covalent chemistry-enabled CTC capture/release platform – “Click Chip”. This platform is designed by integrating bioorthogonal ligation-mediated CTC capture (sensitive and rapid) and disulfide cleavage-driven CTC release (mild, specific, and rapid) on nanostructured substrates to enable efficient purification of CTCs with high-quality CTC-derived mRNA. The CTC-derived mRNA was subjected to RT-droplet digital PCR (RT-ddPCR) or Nanostring nCounter platform. In our proof of concept study, ALK/ROS1 rearrangements were quantified using CTC-mRNA recovered by Click Chips and matched with those identified in biopsy specimen in late-stage ALK/ROS1 positive NSCLC patients. Further, CTC-mRNA recovered from HCC patients by Click Chips can be used for HCC-specific mRNA profiling for predicting HCC prognosis. This streamlined workflow is optimum for non-invasive gene expression profiling based on high-quality CTC-derived mRNA.