European Registration of Cancer Care financed by European Society of Surgical Oncology, Champalimaud Foundation Lisbon, Bas Mulder Award granted by the Alpe d'Huzes Foundation and Dutch Cancer Society, and European Research Council Advanced Grant.

Cancer is as unique as the person fighting it. With the exception of a few biomarker-driven therapies, patients go through rounds of trial-and-error approaches to find the best treatment. Using patient-derived cell lines, we show that zebrafish larvae xenotransplants constitute a fast and highly sensitive in vivo model for differential therapy response, with resolution to reveal intratumor functional cancer heterogeneity. We screened international colorectal cancer therapeutic guidelines and determined distinct functional tumor behaviors (proliferation, metastasis, and angiogenesis) and differential sensitivities to standard therapy. We observed a general higher sensitivity to FOLFIRI [5-fluorouracil(FU)+irinotecan+folinic acid] than to FOLFOX (5-FU+oxaliplatin+folinic acid), not only between isogenic tumors but also within the same tumor. We directly compared zebrafish xenografts with mouse xenografts and show that relative sensitivities obtained in zebrafish are maintained in the rodent model. Our data also illustrate how mutations can provide proliferation advantages in relation to KRASWT and how chemotherapy can unbalance this advantage, selecting for a minor clone resistant to chemotherapy. Zebrafish xenografts provide remarkable resolution to measure Cetuximab sensitivity. Finally, we demonstrate the feasibility of using primary patient samples to generate zebrafish patient-derived xenografts (zPDX) and provide proof-of-concept experiments that compare response to chemotherapy and biological therapies between patients and zPDX. Altogether, our results suggest that zebrafish larvae xenografts constitute a promising fast assay for precision medicine, bridging the gap between genotype and phenotype in an in vivo setting.

Summary Severe sepsis remains a poorly understood systemic inflammatory condition with high mortality rates and limited therapeutic options in addition to organ support measures. Here we show that the clinically approved group of anthracyclines acts therapeutically at a low dose regimen to confer robust protection against severe sepsis in mice. This salutary effect is strictly dependent on the activation of DNA damage response and autophagy pathways in the lung, as demonstrated by deletion of the ataxia telangiectasia mutated (Atm) or the autophagy-related protein 7 (Atg7) specifically in this organ. The protective effect of anthracyclines occurs irrespectively of pathogen burden, conferring disease tolerance to severe sepsis. These findings demonstrate that DNA damage responses, including the ATM and Fancony Anemia pathways, are important modulators of immune responses and might be exploited to confer protection to inflammation-driven conditions, including severe sepsis.

We have previously reported an increase in interleukin (IL)-1β and IL-17 levels, and a continuous activation of caspase-1 in early rheumatoid arthritis (RA) patients. These results suggest that drugs targeting IL-1β regulatory pathways, in addition to tumor necrosis factor (TNF), may constitute promising therapeutic agents in early RA. We have recently used a THP-1 macrophage-like cell line to screen 2320 compounds for those that down-regulate both IL-1β and TNF secretion. Celastrol was one of the most promising therapeutic candidates identified in that study. Our main goal in the present work was to investigate whether administration of celastrol is able to attenuate inflammation in a rat model of adjuvant-induced arthritis (AIA). Moreover, since IL-1β is known to play a role in the polarization of Th17 cells, we also investigate whether administration of digoxin, a specific inhibitor of Th17 cells polarization, is able to attenuate inflammation in the same rat model. We found that celastrol administration significantly suppressed joint inflammation. The histological and immunohistochemical evaluation revealed that celastrol-treated rats had a normal joint structure with complete abrogation of the inflammatory infiltrate and cellular proliferation. In contrast, we observed that digoxin administration significantly ameliorated inflammation but only if administrated in the early phase of disease course (after 4 days of disease induction), and it was not efficient at inhibiting the infiltration of immune cells within the joint and in preventing damage. Thus, our results suggest that celastrol has significant anti-inflammatory and anti-proliferative properties and can constitute a potential anti-inflammatory drug with therapeutic efficacy in the treatment of immune-mediated inflammatory diseases such as RA. Furthermore, we find that early inhibition of Th17 cells polarization ameliorates arthritis but it is not as effective as celastrol.