Inhibition of NAD+-Dependent Metabolic Processes Induces Cellular Necrosis and Tumor Regression in Rhabdomyosarcoma Models.

PURPOSE: Deregulated metabolism in cancer cells represents a vulnerability that may be therapeutically exploited to benefit patients. One such target is nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD+ salvage pathway. NAMPT is necessary for efficient NAD+ production and may be exploited in cells with increased metabolic demands. We have identified NAMPT as a dependency in rhabdomyosarcoma (RMS), a malignancy for which novel therapies are critically needed. Here we describe the effect of NAMPT inhibition on RMS proliferation and metabolism in vitro and in vivo. EXPERIMENTAL DESIGN: Assays of proliferation and cell death were used to determine the effects of pharmacologic NAMPT inhibition in a panel of ten molecularly diverse RMS cell lines. Mechanism of the clinical NAMPTi OT-82 was determined using measures of NAD+ and downstream NAD+-dependent functions, including energy metabolism. We used orthotopic xenograft models to examine tolerability, efficacy, and drug mechanism in vivo. RESULTS: Across all ten RMS cell lines, OT-82 depleted NAD+ and inhibited cell growth at concentrations ≤1 nmol/L. Significant impairment of glycolysis was a universal finding, with some cell lines also exhibiting diminished oxidative phosphorylation. Most cell lines experienced profound depletion of ATP with subsequent irreversible necrotic cell death. Importantly, loss of NAD and glycolytic activity were confirmed in orthotopic in vivo models, which exhibited complete tumor regressions with OT-82 treatment delivered on the clinical schedule. CONCLUSIONS: RMS is highly vulnerable to NAMPT inhibition. These findings underscore the need for further clinical study of this class of agents for this malignancy.

The Role of Procurement Biopsies in Kidney Acceptance Decision Making and Kidney Discard: Perceptions of Physicians, Nurse Coordinators, and OPO Staff and Directors.

Procurement biopsies suffer from challenges with quality and reproducibility and are linked to kidney discard. Nonetheless, procurement biopsies are obtained for the majority of kidneys in the United States, and biopsy findings are commonly relied upon in kidney acceptance decisions. Methods: We conducted in-depth, semistructured interviews with 30 surgeons, nephrologists, nurse coordinators, and organ procurement organization (OPO) staff and directors to assess perceptions of factors contributing to kidney discard and strategies to reduce kidney discard, with a focus on the role of procurement biopsies. Thematic analysis was used to analyze qualitative data. Results: Three main themes emerged: (1) participants emphasized the importance of biopsy findings in making acceptance decisions but expressed concerns about a lack of standardization and quality control; (2) participants reported large variations in the level of importance placed on biopsy findings, the level of reliance on glomerulosclerosis in particular, and the cutoffs used; and (3) participants disagreed about how often procurement biopsies should be taken, with some supporting stricter limits on which kidneys are biopsied and others preferring a biopsy for most kidney offers. Conclusions: These findings support the development of standard practices for which kidneys require biopsy, how the biopsy material is prepared, and how the biopsy is interpreted. Variability in kidney acceptance practices across centers and the use of biopsy findings in guiding recipient selection also lend support to policies to allocate kidneys with suboptimal histological findings to the centers that are willing to use such kidneys and the patients who could most benefit from such offers.

Patient and Clinician Perceptions of Informed Consent and Decision Making About Accepting KDPI > 85 Kidneys.

BACKGROUND: Although the impact of the kidney donor profile index (KDPI) on kidney discard is well researched, less is known about how patients make decisions about whether to give consent for KDPI > 85 kidney offers. METHODS: We conducted in-depth, semistructured interviews with 16 transplant recipients, 15 transplant candidates, and 23 clinicians (transplant surgeons, nephrologists, and nurse coordinators) to assess and compare perceptions of transplant education, informed consent for KDPI > 85 kidneys' and the decision-making process for accepting kidney offers. Thematic analysis was used to analyze qualitative data. RESULTS: Four themes emerged: (1) patients reported uncertainty about the meaning of KDPI or could not recall information about KDPI; (2) patients reported uncertainty about their KDPI > 85 consent status and a limited role in KDPI > 85 consent decision making; (3) patients' reported willingness to consider KDPI > 85 kidneys depended on their age, health status, and experiences with dialysis, and thus it changed over time; (4) patients' underestimated the survival benefit of transplantation compared with dialysis, which could affect their KDPI > 85 consent decision making. CONCLUSIONS: To better support patients' informed decision making about accepting KDPI > 85 kidneys, centers must ensure that all patients receive education about the trade-offs between accepting a KDPI > 85 kidney and remaining on dialysis. Additionally, education about KDPI and discussions about informed consent for KDPI > 85 kidneys must be repeated at multiple time points while patients are on the waiting list.