Application of LDH assay for therapeutic efficacy evaluation of ex vivo tumor models

Funding Information: This work was supported by AbbVie and by iNOVA4Health – UIDB/04462/2020, a program financially supported by Fundação para a Ciência e Tecnologia (FCT) / Ministério da Educação e Ciência, through national funds. RM and TFM were recipients of PhD fellowships funded by FCT (SFRH/BD/132163/2017 and PD/BD/128377/2017, respectively) and CB was funded by “The Discoveries Centre for Regenerative and Precision Medicine” (European Commission Horizon 2020 Research and Innovation programme, under the Grant Agreement 739572). Publisher Copyright: © 2021, The Author(s).The current standard preclinical oncology models are not able to fully recapitulate therapeutic targets and clinically relevant disease biology, evidenced by the 90% attrition rate of new therapies in clinical trials. Three-dimensional (3D) culture systems have the potential to enhance the relevance of preclinical models. However, the limitations of currently available cellular assays to accurately evaluate therapeutic efficacy in these models are hindering their widespread adoption. We assessed the compatibility of the lactate dehydrogenase (LDH) assay in 3D spheroid cultures against other commercially available readout methods. We developed a standardized protocol to apply the LDH assay to ex vivo cultures, considering the impact of culture growth dynamics. We show that accounting for growth rates and background release levels of LDH are sufficient to make the LDH assay a suitable methodology for longitudinal monitoring and endpoint assessment of therapeutic efficacy in both cell line-derived xenografts (xenospheres) and patient-derived explant cultures. This method has the added value of being non-destructive and not dependent on reagent penetration or manipulation of the parent material. The establishment of reliable readout methods for complex 3D culture systems will further the utility of these tumor models in preclinical and co-clinical drug development studies.publishersversionpublishe

Exploring Metabolic Signatures of Ex Vivo Tumor Tissue Cultures for Prediction of Chemosensitivity in Ovarian Cancer

Predicting patient response to treatment and the onset of chemoresistance are still major challenges in oncology. Chemoresistance is deeply influenced by the complex cellular interactions occurring within the tumor microenvironment (TME), including metabolic crosstalk. We have previously shown that ex vivo tumor tissue cultures derived from ovarian carcinoma (OvC) resections retain the TME components for at least four weeks of culture and implemented assays for assessment of drug response. Here, we explored ex vivo patient-derived tumor tissue cultures to uncover metabolic signatures of chemosensitivity and/or resistance. Tissue cultures derived from nine OvC cases were challenged with carboplatin and paclitaxel, the standard-of-care chemotherapeutics, and the metabolic footprints were characterized by LC-MS. Partial least-squares discriminant analysis (PLS-DA) revealed metabolic signatures that discriminated high-responder from low-responder tissue cultures to ex vivo drug exposure. As a proof-of-concept, a set of potential metabolic biomarkers of drug response was identified based on the receiver operating characteristics (ROC) curve, comprising amino acids, fatty acids, pyrimidine, glutathione, and TCA cycle pathways. Overall, this work establishes an analytical and computational platform to explore metabolic features of the TME associated with response to treatment, which can leverage the discovery of biomarkers of drug response and resistance in OvC.publishersversionpublishe

Protocols and characterization data for 2D, 3D, and slice-based tumor models from the PREDECT project

Two-dimensional (2D) culture of cancer cells in vitro does not recapitulate the three-dimensional (3D) architecture, heterogeneity and complexity of human tumors. More representative models are required that better reflect key aspects of tumor biology. These are essential studies of cancer biology and immunology as well as for target validation and drug discovery. The Innovative Medicines Initiative (IMI) consortium PREDECT (www.predect.eu) characterized in vitro models of three solid tumor types with the goal to capture elements of tumor complexity and heterogeneity. 2D culture and 3D mono-and stromal cocultures of increasing complexity, and precision-cut tumor slice models were established. Robust protocols for the generation of these platforms are described. Tissue microarrays were prepared from all the models, permitting immunohistochemical analysis of individual cells, capturing heterogeneity. 3D cultures were also characterized using image analysis. Detailed step-by-step protocols, exemplary datasets from the 2D, 3D, and slice models, and refined analytical methods were established and are presented.Peer reviewe

Systematic review on the recurrence of postoperative nausea and vomiting after a first episode in the recovery room – implications for the treatment of PONV and related clinical trials

BACKGROUND: Despite the presence of a plethora of publications on the prevention of postoperative nausea and vomiting (PONV) only little is known how to treat established symptoms. Besides the high effort of performing these efficacy trials (much more patients must give their consent than are actually included in a study) and ethical concerns, little is known about the rate of re-occurring PONV/vomiting after placebo. As a consequence investigators will have difficulties defining a clinically relevant effect for the new treatment which is crucial for any planning. A quantitative systematic review was performed in order to provide more reliable estimates of the incidence of re-occurring PONV/vomiting after placebo and to help investigators defining a clinically relevant treatment effect. METHODS: A systematic search of the literature was performed using an extended search strategy of a previous review. Data on the recurrence of PONV (any nausea or emetic symptom) and vomiting (retching or vomiting) was extracted from published reports treating PONV with placebo and unpublished results from two observational trials where no treatment was given. A nonlinear random effects model was used to calculate estimates of the recurrence of symptoms and their 95%-confidence intervals (95%-CI). RESULTS: A total of 29 trials (including the unpublished data) were eligible for the calculations. Depending on the length of observation after administering placebo or no treatment the recurrence rate of PONV was between 65% (95%-CI: 53%...75%) and 84% (95%-CI: 73%...91%) and that of vomiting was between 65% (95%-CI: 44%...81%) and 78% (95%-CI: 59%...90%). CONCLUSION: Almost all trials showed a considerable and consistently high rate of recurrence of emetic symptoms after placebo highlighting the need for a consequent antiemetic treatment. Future (placebo) controlled efficacy trials may use the presented empirical estimates for defining clinically relevant effects and for statistical power considerations

Dr Elisabeth Visser. Götter und Kulte im ptolemäischen Alexandrien. Amsterdam, N. V. Noord-Hollandsche Uitg. Mij (Allard Pierson-Stichting, Universi- teit Amsterdam. Archaeologisch-historische Bijdragen. V.)

Boghaert A. Dr Elisabeth Visser. Götter und Kulte im ptolemäischen Alexandrien. Amsterdam, N. V. Noord-Hollandsche Uitg. Mij (Allard Pierson-Stichting, Universi- teit Amsterdam. Archaeologisch-historische Bijdragen. V.). In: L'antiquité classique, Tome 7, fasc. 2, 1938. pp. 429-430

Dr Elisabeth Visser. Götter und Kulte im ptolemäischen Alexandrien. Amsterdam, N. V. Noord-Hollandsche Uitg. Mij (Allard Pierson-Stichting, Universi- teit Amsterdam. Archaeologisch-historische Bijdragen. V.)

Boghaert A. Dr Elisabeth Visser. Götter und Kulte im ptolemäischen Alexandrien. Amsterdam, N. V. Noord-Hollandsche Uitg. Mij (Allard Pierson-Stichting, Universi- teit Amsterdam. Archaeologisch-historische Bijdragen. V.). In: L'antiquité classique, Tome 7, fasc. 2, 1938. pp. 429-430

Grand cortege historique et allegorique organise a Bruxelles pour le 75e anniversaire de l'independance nationale. Programme & notice.

LEIDSSTELSELOPLADEN-RUG0