One hour in vivo-like phenotypic screening system for anti-cancer drugs using a high precision surface plasmon resonance device

[Background/Aims] In anti-cancer drug (candidate) screening, the demand exists for evaluation at physiological concentrations similar to in vivo. This is often performed by three-dimensionally (3D) cultured cells. It necessitates a long culture period of 2-4 weeks with tedious experimental procedures based on endpoint assay and labeling agents causing low reliability. The previous device methods depend on the pharmaceutical mode of action, little related to the conventional method. Furthermore, a separate set of experiments is required to obtain both efficacy and toxicity. Here, we report on a high precision surface plasmon resonance-3D system to overcome all these problems sensing dynamic cellular reaction against target compound(s) by laser.

[Results] We developed the system with average fluctuation of 50 ndeg/s combined with two-dimensionally cultured cells attached onto a sensor chip by applying collagen on the top. The 3D cell activity was shortly obtained by this without cell division. New system gave real-time monitoring of mitochondrial membrane potential (MMP) within live cells without both labeling and invasion. It allowed in vivo-like phenotypic screening for anti-cancer drugs within 1h of drug addition. The data were collected as the stable linear signal change parts for at least 5 min after 25 min following drug addition. The results provided compatibility to clinically related chemosensitivity test (P<0.001) using two cell lines of pancreatic cancer and three anti-cancer drugs to represent differences in individual gene expression and drug mode of action. Early MMP change rate is concluded as a key to quantitatively predict the efficacy and toxicity.