Short term starvation potentiates the efficacy of chemotherapy in triple negative breast cancer via metabolic reprogramming.

BACKGROUND: Chemotherapy (CT) is central to the treatment of triple negative breast cancer (TNBC), but drug toxicity and resistance place strong restrictions on treatment regimes. Fasting sensitizes cancer cells to a range of chemotherapeutic agents and also ameliorates CT-associated adverse effects. However, the molecular mechanism(s) by which fasting, or short-term starvation (STS), improves the efficacy of CT is poorly characterized. METHODS: The differential responses of breast cancer or near normal cell lines to combined STS and CT were assessed by cellular viability and integrity assays (Hoechst and PI staining, MTT or H2DCFDA staining, immunofluorescence), metabolic profiling (Seahorse analysis, metabolomics), gene expression (quantitative real-time PCR) and iRNA-mediated silencing. The clinical significance of the in vitro data was evaluated by bioinformatical integration of transcriptomic data from patient data bases: The Cancer Genome Atlas (TCGA), European Genome-phenome Archive (EGA), Gene Expression Omnibus (GEO) and a TNBC cohort. We further examined the translatability of our findings in vivo by establishing a murine syngeneic orthotopic mammary tumor-bearing model. RESULTS: We provide mechanistic insights into how preconditioning with STS enhances the susceptibility of breast cancer cells to CT. We showed that combined STS and CT enhanced cell death and increased reactive oxygen species (ROS) levels, in association with higher levels of DNA damage and decreased mRNA levels for the NRF2 targets genes NQO1 and TXNRD1 in TNBC cells compared to near normal cells. ROS enhancement was associated with compromised mitochondrial respiration and changes in the metabolic profile, which have a significant clinical prognostic and predictive value. Furthermore, we validate the safety and efficacy of combined periodic hypocaloric diet and CT in a TNBC mouse model. CONCLUSIONS: Our in vitro, in vivo and clinical findings provide a robust rationale for clinical trials on the therapeutic benefit of short-term caloric restriction as an adjuvant to CT in triple breast cancer treatment.

How an outbreak became a pandemic: a chronological analysis of crucial junctures and international obligations in the early months of the COVID-19 pandemic.

Understanding the spread of SARS-CoV-2, how and when evidence emerged, and the timing of local, national, regional, and global responses is essential to establish how an outbreak became a pandemic and to prepare for future health threats. With that aim, the Independent Panel for Pandemic Preparedness and Response has developed a chronology of events, actions, and recommendations, from December, 2019, when the first cases of COVID-19 were identified in China, to the end of March, 2020, by which time the outbreak had spread extensively worldwide and had been characterised as a pandemic. Datapoints are based on two literature reviews, WHO documents and correspondence, submissions to the Panel, and an expert verification process. The retrospective analysis of the chronology shows a dedicated initial response by WHO and some national governments, but also aspects of the response that could have been quicker, including outbreak notifications under the International Health Regulations (IHR), presumption and confirmation of human-to-human transmission of SARS-CoV-2, declaration of a Public Health Emergency of International Concern, and, most importantly, the public health response of many national governments. The chronology also shows that some countries, largely those with previous experience with similar outbreaks, reacted quickly, even ahead of WHO alerts, and were more successful in initially containing the virus. Mapping actions against IHR obligations, the chronology shows where efficiency and accountability could be improved at local, national, and international levels to more quickly alert and contain health threats in the future. In particular, these improvements include necessary reforms to international law and governance for pandemic preparedness and response, including the IHR and a potential framework convention on pandemic preparedness and response.

Hydroxycarboxylic acid receptor 3 and GPR84 - Two metabolite-sensing G protein-coupled receptors with opposing functions in innate immune cells.

G protein-coupled receptors (GPCRs) are key regulatory proteins of immune cell function inducing signaling in response to extracellular (pathogenic) stimuli. Although unrelated, hydroxycarboxylic acid receptor 3 (HCA3) and GPR84 share signaling via Gαi/o proteins and the agonist 3-hydroxydecanoic acid (3HDec). Both receptors are abundantly expressed in monocytes, macrophages and neutrophils but have opposing functions in these innate immune cells. Detailed insights into the molecular mechanisms and signaling components involved in immune cell regulation by GPR84 and HCA3 are still lacking. Here, we report that GPR84-mediated pro-inflammatory signaling depends on coupling to the hematopoietic cell-specific Gα15 protein in human macrophages, while HCA3 exclusively couples to Gαi protein. We show that activated GPR84 induces Gα15-dependent ERK activation, increases intracellular Ca2+ and IP3 levels as well as ROS production. In contrast, HCA3 activation shifts macrophage metabolism to a less glycolytic phenotype, which is associated with anti-inflammatory responses. This is supported by an increased release of anti-inflammatory IL-10 and a decreased secretion of pro-inflammatory IL-1ß. In primary human neutrophils, stimulation with HCA3 agonists counteracts the GPR84-induced neutrophil activation. Our analyses reveal that 3HDec acts solely through GPR84 but not HCA3 activation in macrophages. In summary, this study shows that HCA3 mediates hyporesponsiveness in response to metabolites derived from dietary lactic acid bacteria and uncovers that GPR84, which is already targeted in clinical trials, promotes pro-inflammatory signaling via Gα15 protein in macrophages.

XCMS-MRM and METLIN-MRM: a cloud library and public resource for targeted analysis of small molecules.

We report XCMS-MRM and METLIN-MRM ( http://xcmsonline-mrm.scripps.edu/ and http://metlin.scripps.edu/ ), a cloud-based data-analysis platform and a public multiple-reaction monitoring (MRM) transition repository for small-molecule quantitative tandem mass spectrometry. This platform provides MRM transitions for more than 15,500 molecules and facilitates data sharing across different instruments and laboratories.

Revitalization of integrated disease surveillance and response in Sierra Leone post Ebola virus disease outbreak.

BACKGROUND: The Ministry of Health and Sanitation (MOHS) in Sierra Leone partially rolled out the implementation of Integrated Disease Surveillance and Response (IDSR) in 2003. After the Ebola virus disease outbreak in 2014-2015, there was need to strengthen IDSR to ensure prompt detection and response to epidemic-prone diseases. We describe the processes, successes and challenges of revitalizing public health surveillance in a country recovering from a protracted Ebola virus disease outbreak. METHODS: The revitalization process began with adaptation of the revised IDSR guidelines and development of customized guidelines to suit the health care systems in Sierra Leone. Public health experts defined data flow, system operations, case definitions, frequency and channels of reporting and dissemination. Next, phased training of IDSR focal persons in each health facility and the distribution of data collection and reporting tools was done. Monitoring activities included periodic supportive supervision and data quality assessments. Rapid response teams were formed to investigate and respond to disease outbreak alerts in all districts. RESULTS: Submission of reports through the IDSR system began in mid-2015 and by the 35th epidemiologic week, all district health teams were submitting reports. The key performance indicators measuring the functionality of the IDSR system in 2016 and 2017 were achieved (WHO Africa Region target ≥80%); the annual average proportion of timely weekly health facility reports submitted to the next level was 93% in 2016 and 97% in 2017; the proportion of suspected outbreaks and public health events detected through the IDSR system was 96% (n = 87) in 2016 and 100% (n = 85) in 2017. CONCLUSION: With proper planning, phased implementation and adequate investment of resources, it is possible to establish a functional IDSR system in a country recovering from a public health crisis. A functional IDSR system requires well trained workforce, provision of the necessary tools and guidelines, information, communication and technology infrastructure to support data transmission, provision of timely feedback as well as logistical support.

Current Status and Future Prospects of Clinically Exploiting Cancer-specific Metabolism-Why Is Tumor Metabolism Not More Extensively Translated into Clinical Targets and Biomarkers?

Tumor cells exhibit a specialized metabolism supporting their superior ability for rapid proliferation, migration, and apoptotic evasion. It is reasonable to assume that the specific metabolic needs of the tumor cells can offer an array of therapeutic windows as pharmacological disturbance may derail the biochemical mechanisms necessary for maintaining the tumor characteristics, while being less important for normally proliferating cells. In addition, the specialized metabolism may leave a unique metabolic signature which could be used clinically for diagnostic or prognostic purposes. Quantitative global metabolic profiling (metabolomics) has evolved over the last two decades. However, despite the technology's present ability to measure 1000s of endogenous metabolites in various clinical or biological specimens, there are essentially no examples of metabolomics investigations being translated into actual utility in the cancer clinic. This review investigates the current efforts of using metabolomics as a tool for translation of tumor metabolism into the clinic and further seeks to outline paths for increasing the momentum of using tumor metabolism as a biomarker and drug target opportunity.

Tuning Metabolome Coverage in Reversed Phase LC-MS Metabolomics of MeOH Extracted Samples Using the Reconstitution Solvent Composition.

Considering the physicochemical diversity of the metabolome, untargeted metabolomics will inevitably discriminate against certain compound classes. Efforts are nevertheless made to maximize the metabolome coverage. Contrary to the main steps of a typical liquid chromatography-mass spectrometry (LC-MS) metabolomics workflow, such as metabolite extraction, the sample reconstitution step has not been optimized for maximal metabolome coverage. This sample concentration step typically occurs after metabolite extraction, when dried samples are reconstituted in a solvent for injection on column. The aim of this study was to evaluate the impact of the sample reconstitution solvent composition on metabolome coverage in untargeted LC-MS metabolomics. Lysogeny Broth medium samples reconstituted in MeOH/H2O ratios ranging from 0 to 100% MeOH and analyzed with untargeted reversed phase LC-MS showed that the highest number of metabolite features (n = 1500) was detected in samples reconstituted in 100% H2O. As compared to a commonly used reconstitution solvent mixture of 50/50 MeOH/H2O, our results indicate that the small fraction of compounds increasing in peak area response by the addition of MeOH to H2O, 5%, is outweighed by the fraction of compounds with decreased response, 57%. We evaluated our results on human serum samples from lymphoma patients and healthy control subjects. Reconstitution in 100% H2O resulted in a higher number of significant metabolites discriminating between these two groups than both 50% and 100% MeOH. These findings show that the sample reconstitution step has a clear impact on the metabolome coverage of MeOH extracted biological samples, highlighting the importance of the reconstitution solvent composition for untargeted discovery metabolomics.