Innate immune activation by checkpoint inhibition in human patient-derived lung cancer tissues.

Although Pembrolizumab-based immunotherapy has significantly improved lung cancer patient survival, many patients show variable efficacy and resistance development. A better understanding of the drug's action is needed to improve patient outcomes. Functional heterogeneity of the tumor microenvironment (TME) is crucial to modulating drug resistance; understanding of individual patients' TME that impacts drug response is hampered by lack of appropriate models. Lung organotypic tissue slice cultures (OTC) with patients' native TME procured from primary and brain-metastasized (BM) non-small cell lung cancer (NSCLC) patients were treated with Pembrolizumab and/or beta-glucan (WGP, an innate immune activator). Metabolic tracing with 13C6-Glc/13C5,15N2-Gln, multiplex immunofluorescence, and digital spatial profiling (DSP) were employed to interrogate metabolic and functional responses to Pembrolizumab and/or WGP. Primary and BM PD-1+ lung cancer OTC responded to Pembrolizumab and Pembrolizumab + WGP treatments, respectively. Pembrolizumab activated innate immune metabolism and functions in primary OTC, which were accompanied by tissue damage. DSP analysis indicated an overall decrease in immunosuppressive macrophages and T cells but revealed microheterogeneity in immune responses and tissue damage. Two TMEs with altered cancer cell properties showed resistance. Pembrolizumab or WGP alone had negligible effects on BM-lung cancer OTC but Pembrolizumab + WGP blocked central metabolism with increased pro-inflammatory effector release and tissue damage. In-depth metabolic analysis and multiplex TME imaging of lung cancer OTC demonstrated overall innate immune activation by Pembrolizumab but heterogeneous responses in the native TME of a patient with primary NSCLC. Metabolic and functional analysis also revealed synergistic action of Pembrolizumab and WGP in OTC of metastatic NSCLC.

De novo synthesis of serine and glycine fuels purine nucleotide biosynthesis in human lung cancer tissues.

Nucleotide synthesis is essential to proliferating cells, but the preferred precursors for de novo biosynthesis are not defined in human cancer tissues. We have employed multiplexed stable isotope-resolved metabolomics to track the metabolism of [13C6]glucose, D2-glycine, [13C2]glycine, and D3-serine into purine nucleotides in freshly resected cancerous and matched noncancerous lung tissues from nonsmall cell lung cancer (NSCLC) patients, and we compared the metabolism with established NSCLC PC9 and A549 cell lines in vitro Surprisingly, [13C6]glucose was the best carbon source for purine synthesis in human NSCLC tissues, in contrast to the noncancerous lung tissues from the same patient, which showed lower mitotic indices and MYC expression. We also observed that D3-Ser was preferentially incorporated into purine rings over D2-glycine in both tissues and cell lines. MYC suppression attenuated [13C6]glucose, D3-serine, and [13C2]glycine incorporation into purines and reduced proliferation in PC9 but not in A549 cells. Using detailed kinetic modeling, we showed that the preferred use of glucose as a carbon source for purine ring synthesis in NSCLC tissues involves cytoplasmic activation/compartmentation of the glucose-to-serine pathway and enhanced reversed one-carbon fluxes that attenuate exogenous serine incorporation into purines. Our findings also indicate that the substrate for de novo nucleotide synthesis differs profoundly between cancer cell lines and fresh human lung cancer tissues; the latter preferred glucose to exogenous serine or glycine but not the former. This distinction in substrate utilization in purine synthesis in human cancer tissues should be considered when targeting one-carbon metabolism for cancer therapy.

Identifying Esophagectomy Patients at Risk for Predischarge Versus Postdischarge Venous Thromboembolism.

BACKGROUND: Current guidelines recommend postoperative venous thromboembolism (VTE) chemoprophylaxis for moderate-risk patients (3% rate or greater) and extended-duration chemoprophylaxis for high-risk patients (6% or greater). Large-scale studies of and recommendations for esophagectomy patients are lacking. This study was designed to evaluate the timing, rates, and predictors of postesophagectomy VTE. METHODS: Patients undergoing esophagectomies for cancer were identified from the 2005 to 2012 American College of Surgeons National Surgical Quality Improvement database. Timing and rates of VTE (deep venous thrombosis or pulmonary embolism, or both) were calculated. Events were stratified as predischarge or postdischarge. Perioperative factors associated with 30-day rates of predischarge and postdischarge VTE were analyzed. RESULTS: Of 3,208 patients analyzed, the surgical approach was Ivor-Lewis (n = 1,131, 35.3%), transhiatal (n = 945, 29.5%), three-field (n = 587, 18.3%), thoracoabdominal (n = 364, 11.3%), and nongastric conduit reconstruction (n = 181, 5.6%). Rates were 2.0% pulmonary embolism, 3.7% deep venous thrombosis, and 5.1% VTE. Overall median length of stay was 11 days (versus 19 days, p < 0.001, if predischarge VTE). Predischarge VTE occurred on median day 9, whereas postdischarge VTE occurred on day 19 (p < 0.001). Only 17% of VTE occurred after discharge. Multivariate analysis identified being male (odds ratio [OR] 2.09, p = 0.018), white race (OR 1.93, p = 0.004), prolonged ventilation (OR 3.24, p < 0.001), and other major complications (OR 1.90, p = 0.005) as independent predictors of predischarge VTE. Older age (OR 1.06 per year, p = 0.006) and major complications (OR 3.14, p = 0.004) were independently associated with postdischarge VTE. CONCLUSIONS: Postesophagectomy VTE occurs in a clinically significant proportion of esophageal cancer patients with identifiable risk factors for predischarge and postdischarge events. Elderly patients and patients with major complications are most likely to benefit from extended-duration chemoprophylaxis.