Patient-derived micro-organospheres enable clinical precision oncology.

Patient-derived xenografts (PDXs) and patient-derived organoids (PDOs) have been shown to model clinical response to cancer therapy. However, it remains challenging to use these models to guide timely clinical decisions for cancer patients. Here, we used droplet emulsion microfluidics with temperature control and dead-volume minimization to rapidly generate thousands of micro-organospheres (MOSs) from low-volume patient tissues, which serve as an ideal patient-derived model for clinical precision oncology. A clinical study of recently diagnosed metastatic colorectal cancer (CRC) patients using an MOS-based precision oncology pipeline reliably assessed tumor drug response within 14 days, a timeline suitable for guiding treatment decisions in the clinic. Furthermore, MOSs capture original stromal cells and allow T cell penetration, providing a clinical assay for testing immuno-oncology (IO) therapies such as PD-1 blockade, bispecific antibodies, and T cell therapies on patient tumors.

On the potential of in vitro organ-chip models to define temporal pharmacokinetic-pharmacodynamic relationships.

Functional human-on-a-chip systems hold great promise to enable quantitative translation to in vivo outcomes. Here, we explored this concept using a pumpless heart only and heart:liver system to evaluate the temporal pharmacokinetic/pharmacodynamic (PKPD) relationship for terfenadine. There was a time dependent drug-induced increase in field potential duration in the cardiac compartment in response to terfenadine and that response was modulated using a metabolically competent liver module that converted terfenadine to fexofenadine. Using this data, a mathematical model was developed to predict the effect of terfenadine in preclinical species. Developing confidence that microphysiological models could have a transformative effect on drug discovery, we also tested a previously discovered proprietary AstraZeneca small molecule and correctly determined the cardiotoxic response to its metabolite in the heart:liver system. Overall our findings serve as a guiding principle to future investigations of temporal concentration response relationships in these innovative in vitro models, especially, if validated across multiple time frames, with additional pharmacological mechanisms and molecules representing a broad chemical diversity.

Calcineurin-dependent cardiomyopathy is activated by TRPC in the adult mouse heart.

The manner in which Ca2+-sensitive signaling proteins are activated in contracting cardiomyocytes is an intriguing theoretical problem given that the cytoplasm is continually bathed with systolic Ca2+ concentrations that should maximally activate most Ca2+-sensitive signaling kinases and phosphatases. Store-operated Ca2+ entry, partially attributed to transient receptor potential (TRP) proteins, can mediate activation of the Ca2+-sensitive phosphatase calcineurin in nonexcitable cells. Here we investigated the gain-of-function phenotype associated with TRPC3 expression in the mouse heart using transgenesis to examine the potential role of store-operated Ca2+ entry in regulating cardiac calcineurin activation and ensuing hypertrophy/myopathy. Adult myocytes isolated from TRPC3 transgenic mice showed abundant store-operated Ca2+ entry that was inhibited with SKF96365 but not verapamil or KB-R7943. Associated with this induction in store-operated Ca2+ entry, TRPC3 transgenic mice showed increased calcineurin-nuclear factor of activated T cells (NFAT) activation in vivo, cardiomyopathy, and increased hypertrophy after neuroendocrine agonist or pressure overload stimulation. The cardiomyopathic phenotype and increased hypertrophy after pressure overload stimulation were blocked by targeted disruption of the calcineurin Abeta gene. Thus, enhanced store-operated Ca2+ entry in the heart can regulate calcineurin-NFAT signaling in vivo, which could secondarily impact the hypertrophic response and cardiomyopathy.