Citations

Abstract Background: Tumor surface PD-L1 (B7-H1) signals through T-cell surface receptor PD-1 to suppress antitumor immunity. PD-1 inhibitors like pembrolizumab block this pathway to prevent tumor escape from immunosurveillance. These PD-1 checkpoint inhibitors achieve objective response in 20-30% of patients with melanoma (1-3). As the majority of these patients are resistant to this treatment, there is a critical need to combat PD-1 checkpoint inhibitor resistance in melanoma. What is the mechanism of PD-1 checkpoint inhibitor resistance in melanoma? Our group has reported that soluble PD-L1 (sPD-L1, sB7-H1) is elevated in the serum of patients with PD-1 inhibitor-resistant melanoma and non-small cell lung cancer (NSCLC) (4). We have also shown that soluble PD-L1 is produced by cleavage from other tumor types and leads to apoptosis in CD8+ T-cells (5). The aim of this study is to confirm the source of sPD-L1 in human melanoma and its relation to outcomes. Methods: B7H1-expressing transgenic melanoma cells (Mel-B7H1) were treated with an array of protease inhibitors over 24 hours. Cells were then pelleted and supernatants were analyzed by ELISA for sPD-L1 (sB7-H1) production. Tumor serum samples were also analyzed by ELISA for sPD-L1 production.Tumor pathology slides from patients with melanoma (serum donors from the above study) were stained by immunohistochemistry with antibodies against proteases ADAM10 or ADAM17. Slides were visualized by microscopy for the presence of these antigens. Activated human CD8+ T-cells were cultured with recombinant human B7-H1 (PD-L1) protein, sPD-L1-rich, or sPD-L1-depleted supernatants from a tumor cell line in the presence of placebo or PD-1 checkpoint inhibitor antibodies. Cell survival was measured at 48 hours by flow cytometry.Results: ADAM10 inhibitor GI254023X, ADAM17 inhibitor TAPI-0, and broad metalloprotease inhibitor TAPI-2 inhibited Mel-B7H1 production of sB7H1 (p<0.001, 0.095, and 0.001 respectively). Specific inhibitors of other metalloproteases did not significantly alter sB7H1 production. PD-L1 transcription levels were not significantly altered. Tumor pathology slides from patients with high serum sPD-L1 exhibited high ADAM10 and/or ADAM17 staining. Conversely, tumors from patients with low-sPD-L1levels tended to exhibit low ADAM10 and/or ADAM17 staining. Recombinant PD-L1 and PD-L1-rich supernatants induced cell death of CD8+ T-cells, whereas PBS control solution and PD-L1-depleted supernatants did not. Supraphysiologic doses of pembrolizumab decreased cell death in PD-L1-rich supernatant-treated CD8+ T-cells. Conclusions: Matrix metalloprotease inhibitors ADAM10 and ADAM17 mediate sPD-L1 production from melanoma cells. In samples from patients with melanoma, immunohistochemical staining of these proteases in tumor tissue correlates with serum sPD-L1 levels. As we have shown previously, sPD-L1 induces apoptosis of activated CD8+ T-cells, which may explain PD-1 inhibitor resistance in most patients with melanoma.We posit that sPD-L1 outcompetes PD-1 inhibitors to suppress tumor immunosurveillance. Our results suggest that the combination of ADAM10/17 inhibitor and PD-1 checkpoint inhibitor may overcome this mechanism of PD-1 resistance in melanoma and other cancers. Future studies will determine (A) how a combined ADAM10/17 inhibitor and PD-1 inhibitor may function in clinical use, (B) how tumor-derived sPD-L1 signals downstream to cause apoptosis in T-cells, and (C) whether surface ADAM10/17 predict surface PD-L1 staining in melanoma. References: 1. Ribas et al., Lancet Oncol 2015;16(8):908–18. 2. Hamid et al., Ann Oncol 2016;27:6. 3. Weber et al., Lancet Oncol 2015:16(4):375–84. 4. Dronca et al., J Clin Oncol 2017:35(15):11534. 5. Orme et al., AACR Adv Malig Lymphoma 2018. Citation Format: Jacob J. Orme, Khalid Jazieh, Susan Harrington, Matthew Ball, Tariq U. Azam, Xin (Cindy) Liu, Tiancheng Xie, Aaron Mansfield, Roxana S. Dronca, Haidong Dong. Tumor-associated ADAM10 and ADAM17 produce soluble PD-L1 (sPD-L1, sB7-H1) and affect downstream tumor immunity – A resistance mechanism to PD-1 checkpoint blockade in melanoma [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A210.

Abstract Genome-wide association studies (GWAS) have so far identified 25 loci associated with glioma risk, with most showing specificity for either glioblastoma (GBM) or non-GBM tumors. The majority of these GWAS susceptibility variants reside in noncoding regions and the causal genes underlying the associations are largely unknown. Here we performed a transcriptome-wide association study to search for novel risk loci and candidate causal genes at known GWAS loci using Genotype-Tissue Expression Project (GTEx) data to predict cis-predicted gene expression in relation to GBM and non-GBM risk in conjunction with GWAS summary statistics on 12,488 glioma cases (6,183 GBM and 5,820 non-GBM) and 18,169 controls. Imposing a Bonferroni-corrected significance level of P < 5.69 × 10−6, we identified 31 genes, including GALNT6 at 12q13.33, as a candidate novel risk locus for GBM (mean Z = 4.43; P = 5.68 × 10−6). GALNT6 resides at least 55 Mb away from any previously identified glioma risk variant, while all other 30 significantly associated genes were located within 1 Mb of known GWAS-identified loci and were not significant after conditioning on the known GWAS-identified variants. These data identify a novel locus (GALNT6 at 12q13.33) and 30 genes at 12 known glioma risk loci associated with glioma risk, providing further insights into glioma tumorigenesis. Significance: This study identifies new genes associated with glioma risk, increasing understanding of how these tumors develop.

Objective The aim of this study is to investigate the association between emergency department (ED) organizational models and the risk of death within 7 days of ED discharge. Patients and methods We included Danish ED discharges between 1 January 2011 and 24 December 2014 that led to death within 7 days of discharge. The inclusion criterion was age older than 18 years. The exclusion criterion was further in-hospital admission. First model (Virtual): other departments employ interns who perform ED tasks. They are responsible for ED patient care and prioritize their task order between their own department and the ED. Second model (Hybrid): the ED/other departments perform tasks; interns/consultants are employed by the ED/other departments. The ED/other departments have patient care responsibility. Third model (Independent): the ED performs all tasks; employs interns/consultants; and have patient care responsibility. Sex, age, Charlson Comorbidity Index score, and primary diagnosis were used to describe patient characteristics. We calculated the risk of death within 7 days of discharge using multiple logistic regression analysis. Results In 805 out of 201 299 discharges included in the study, the patient died within 7 days. Compared with the Virtual model, the odds ratio for death within 7 days of discharge was 0.72 (95% confidence interval: 0.59–0.92) for the Independent model and 0.75 (95% confidence interval: 0.61–0.92) for the Hybrid+Virtual model. Increased risk was associated with male sex, older age, and a medium or a high Charlson Comorbidity Index score. Conclusion Compared with discharges from a Virtual model, the risk of death within 7 days of discharge was lower if the ED had an Independent or a Hybrid+Virtual model.

AbstractBACKGROUNDClinical practice guidelines recommend estimation of glomerular filtration rate (eGFR) using validated equations based on serum creatinine (eGFRcr), cystatin C (eGFRcys), or both (eGFRcr-cys). However, when compared with the measured GFR (mGFR), only eGFRcr-cys meets recommended performance standards. Our goal was to develop a more accurate eGFR method using a panel of metabolites without creatinine, cystatin C, or demographic variables.METHODSAn ultra-performance liquid chromatography–tandem mass spectrometry assay for acetylthreonine, phenylacetylglutamine, pseudouridine, and tryptophan was developed, and a 20-day, multiinstrument analytical validation was conducted. The assay was tested in 2424 participants with mGFR data from 4 independent research studies. A new GFR equation (eGFRmet) was developed in a random subset (n = 1615) and evaluated in the remaining participants (n = 809). Performance was assessed as the frequency of large errors [estimates that differed from mGFR by at least 30% (1 − P30); goal <10%].RESULTSThe assay had a mean imprecision (≤10% intraassay, ≤6.9% interassay), linearity over the quantitative range (r2 > 0.98), and analyte recovery (98.5%–113%). There was no carryover, no interferences observed, and analyte stability was established. In addition, 1 − P30 in the validation set for eGFRmet (10.0%) was more accurate than eGFRcr (13.1%) and eGFRcys (12.0%) but not eGFRcr-cys (8.7%). Combining metabolites, creatinine, cystatin C, and demographics led to the most accurate equation (7.0%). Neither equation had substantial variation among population subgroups.CONCLUSIONSThe new eGFRmet equation could serve as a confirmatory test for GFR estimation.

Sepsis continues to be a leading cause of mortality and morbidity in the intensive care unit. Cardiovascular dysfunction in sepsis is associated with worse short- and long-term outcomes. Sepsis-related myocardial dysfunction is noted in 20%–65% of these patients and manifests as isolated or combined left or right ventricular systolic or diastolic dysfunction Echocardiography is the most commonly used modality for the diagnosis of sepsis-related myocardial dysfunction. With the increasing use of ultrasonography in the intensive care unit, there is a renewed interest in sepsis-related myocardial dysfunction. This review summarises the current scope of literature focused on sepsis-related myocardial dysfunction and highlights the use of basic and advanced echocardiographic techniques for the diagnosis of sepsis-related myocardial dysfunction and the management of sepsis and septic shock.

Abstract Airway smooth muscle (ASM) regulation of airway structure and contractility is critical in fetal/neonatal physiology in health and disease. Fetal lungs experience higher Ca 2+ environment that may impact extracellular Ca 2+ ([Ca 2+ ] o ) sensing receptor (CaSR). Well‐known in the parathyroid gland, CaSR is also expressed in late embryonic lung mesenchyme. Using cells from 18‐22 week human fetal lungs, we tested the hypothesis that CaSR regulates intracellular Ca 2+ ([Ca 2+ ] i ) in fetal ASM (fASM). Compared with adult ASM, CaSR expression was higher in fASM, while fluorescence Ca 2+ imaging showed that [Ca 2+ ] i was more sensitive to altered [Ca 2+ ] o . The fASM [Ca 2+ ] i responses to histamine were also more sensitive to [Ca 2+ ] o (0–2 mM) compared with an adult, enhanced by calcimimetic R568 but blunted by calcilytic NPS2143. [Ca 2+ ] i was enhanced by endogenous CaSR agonist spermine (again higher sensitivity compared with adult). Inhibition of phospholipase C (U73122; siRNA) or inositol 1,4,5‐triphosphate receptor (Xestospongin C) blunted [Ca 2+ ] o sensitivity and R568 effects. NPS2143 potentiated U73122 effects. Store‐operated Ca 2+ entry was potentiated by R568. Traction force microscopy showed responsiveness of fASM cellular contractility to [Ca 2+ ] o and NPS2143. Separately, fASM proliferation showed sensitivity to [Ca 2+ ] o and NPS2143. These results demonstrate functional CaSR in developing ASM that modulates airway contractility and proliferation.