Patients with non-small cell lung cancer (NSCLC) often benefit from treatment with tyrosine kinase inhibitors (TKIs), particularly if the tumors express activating mutations for EGFR. While screening patients for EGFR activating mutations can help predict which tumors will respond to the drug, there are times when EGFR genotyping does not accurately predict drug response. In a recent issue of PLoS ONE, Guisier et al. develop a method to rapidly assess the sensitivity of tumors to TKIs using probe-based confocal endomicroscopy (pCLE) and the fluorescent caspase substrate, NucView™ 488.
The researchers transplanted tumor cell lines that were known to be either sensitive or insensitive to the TKI Erlotinib into nude mice. After tumors developed, they explanted the tumors and briefly treated them ex-vivo with DMSO or drug, and then stained with NucView™ to monitor apoptosis. NucView™ fluorescence positively labeled tumors from known drug-sensitive cell lines, but not tumors from resistant cell lines. They then used pCLE to image the tumors in vivo. Again, NucView™ fluorescence identified tumors from Erlotinib-sensitive cell lines, but not resistant cells. If validated in humans, this technique could be used to quickly determine which patients would be most likely to respond to a drug, saving time and improving outcomes.
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Guisier F, Bohn P, Patout M, Piton N, Farah I, Vera P, et al. (2017) In- and ex-vivo molecular imaging of apoptosis to assess sensitivity of non-small cell lung cancer to EGFR inhibitors using probe-based confocal laser endomicroscopy. PLoS ONE 12(7): e0180576. https://doi.org/10.1371/journal.pone.0180576