New insights into marine group III Euryarchaeota, from dark to light

Marine Euryarchaeota remain among the least understood major components of marine microbial communities. Marine group II Euryarchaeota (MG-II) are more abundant in surface waters (4–20% of the total prokaryotic community), whereas marine group III Euryarchaeota (MG-III) are generally considered low-abundance members of deep mesopelagic and bathypelagic communities. Using genome assembly from direct metagenome reads and metagenomic fosmid clones, we have identified six novel MG-III genome sequence bins from the photic zone (Epi1–6) and two novel bins from deep-sea samples (Bathy1–2). Genome completeness in those genome bins varies from 44% to 85%. Photic-zone MG-III bins corresponded to novel groups with no similarity, and significantly lower GC content, when compared with previously described deep-MG-III genome bins. As found in many other epipelagic microorganisms, photic-zone MG-III bins contained numerous photolyase and rhodopsin genes, as well as genes for peptide and lipid uptake and degradation, suggesting a photoheterotrophic lifestyle. Phylogenetic analysis of these photolyases and rhodopsins as well as their genomic context suggests that these genes are of bacterial origin, supporting the hypothesis of an MG-III ancestor that lived in the dark ocean. Epipelagic MG-III occur sporadically and in relatively small proportions in marine plankton, representing only up to 0.6% of the total microbial community reads in metagenomes. None of the reconstructed epipelagic MG-III genomes were present in metagenomes from aphotic zone depths or from high latitude regions. Most low-GC bins were highly enriched at the deep chlorophyll maximum zones, with the exception of Epi1, which appeared evenly distributed throughout the photic zone worldwideThis work was supported by projects MEDIMAX BFPU2013–48007-P from the Spanish Ministerio de Economía y CompetitividadMaCuMBA Project 311975 of the European Commission FP7Project AQUAMET II/2014/012 from the Generalitat Valenciana and by the French Agence Nationale de la Recherche (ANR-08-GENM-024–001,EVOLDEEP).JHM was supported with a PhD fellowship from the Spanish Ministerio de Economía y Competitividad

Engineering patient-on-a-chip models for personalized cancer medicine

Traditional in vitro and in vivo models typically used in cancer research have demonstrated a low predictive power for human response. This leads to high attrition rates of new drugs in clinical trials, which threaten cancer patient prognosis. Tremendous efforts have been directed towards the development of a new generation of highly predictable preclinical models capable to reproduce in vitro the biological complexity of the human body. Recent advances in nanotechnology and tissue engineering have enabled the development of predictive organs-on-a-chip models of cancer with advanced capabilities. These models can reproduce in  vitro the complex three-dimensional physiology and interactions that occur between organs and tissues in vivo, offering multiple advantages when compared to traditional models. Importantly, these models can be tailored to the biological complexity of individual cancer patients resulting into biomimetic and personalized cancer patient-on-a-chip platforms. The individualized models provide a more accurate and physiological environment to predict tumor progression on patients and their response to drugs. In this chapter, we describe the latest advances in the field of cancer patient-on-a-chip, and discuss about their main applications and current challenges. Overall, we anticipate that this new paradigm in cancer in vitro models may open up new avenues in the field of personalized â cancer â medicine, which may allow pharmaceutical companies to develop more efficient drugs, and clinicians to apply patient-specific therapies. The authors acknowledge the financial support from the European Union Framework Programme for Research and Innovation Horizon 2020 on Forefront Research in 3D Disease Cancer Models as in vitro Screening Technologies (FoReCaST) under grant agreement no. 668983. D.C. and S.C.K also acknowledge the support from the Portuguese Foundation for Science and Technology (FCT) under the scope of the project Modelling Cancer Metastasis into the Human Microcirculation System using a Multiorgan-on-a-Chip Approach (2MATCH) (02/SAICT/2017 – n° 028070) funded by the Programa Operacional Regional do Norte supported by FEDER. Conflicts of interest: none