SLC7A5 is required for cancer cell growth under arginine-limited conditions.

Tumor cells must optimize metabolite acquisition between synthesis and uptake from a microenvironment characterized by hypoxia, lactate accumulation, and depletion of many amino acids, including arginine. We performed a metabolism-focused functional screen using CRISPR-Cas9 to identify pathways and factors that enable tumor growth in an arginine-depleted environment. Our screen identified the SLC-family transporter SLC7A5 as required for growth, and we hypothesized that this protein functions as a high-affinity citrulline transporter.

Accelerating evidence generation: Addressing critical challenges and charting a path forward.

Efficient evidence generation to assess the clinical and economic impact of medical therapies is critical amid rising healthcare costs and aging populations. However, drug development and clinical trials remain far too expensive and inefficient for all stakeholders. On October 25-26, 2023, the Duke Clinical Research Institute brought together leaders from academia, industry, government agencies, patient advocacy, and nonprofit organizations to explore how different entities and influencers in drug development and healthcare can realign incentive structures to efficiently accelerate evidence generation that addresses the highest public health needs.

Bacterial microcompartment utilization in the human commensal Nissle 1917.

Unlabelled: Bacterial microcompartments (BMCs) are self-assembled protein structures often utilized by bacteria as a modular metabolic unit, enabling the catalysis and utilization of less common carbon and nitrogen sources within a self-contained compartment. The BMC has been widely demonstrated in enteropathogens, such as , and current research is exploring its activity in the commensal species that populate the human gut. Nissle 1917 (EcN) is a strong colonizer and probiotic in gut microbial communities and has been used extensively for microbiome engineering.

Direct mitochondrial import of lactate supports resilient carbohydrate oxidation.

Lactate is the highest turnover circulating metabolite in mammals. While traditionally viewed as a waste product, lactate is an important energy source for many organs, but first must be oxidized to pyruvate for entry into the tricarboxylic acid cycle (TCA cycle). This reaction is thought to occur in the cytosol, with pyruvate subsequently transported into mitochondria via the mitochondrial pyruvate carrier (MPC).