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Background: Metabolic perturbations arising from malignant transformation have not been systematically characterized in human lung cancers in situ. Stable isotope resolved metabolomic analysis (SIRM) enables functional analysis of gene dysregulations in lung cancer. To this purpose, metabolic changes were investigated by infusing uniformly labeled 13 C-glucose into human lung cancer patients, followed by resection and processing of paired non-cancerous lung and non small cell carcinoma tissues. NMR and GC-MS were used for 13 C-isotopomer-based metabolomic analysis of the extracts of tissues and blood plasma.

Summary The lactate dehydrogenase-A (LDH-A) enzyme catalyzes the inter-conversion of pyruvate and lactate, is upregulated in human cancers and is associated with aggressive tumor outcomes. Here we use a novel inducible murine model and demonstrate that inactivation of LDH-A in mouse models of NSCLC driven by oncogenic K-RAS or EGFR leads to decreased tumorigenesis and disease regression in established tumors. We also show that abrogation of LDH-A results in reprogramming of pyruvate metabolism, with decreased lactic fermentation in vitro, in vivo, and ex vivo. This was accompanied by re-activation of mitochondrial function in vitro but not in vivo or ex vivo. Finally, using a specific small molecule LDH-A inhibitor, we demonstrated that LDH-A is essential for cancer initiating cell survival and proliferation. Thus, LDH-A can be a viable therapeutic target for NSCLC including cancer stem cell-dependent drug resistant tumors.

Macrophages have been linked to tumor initiation, progression, metastasis, and treatment resistance. However, the transcriptional regulation of macrophages driving the protumor function remains elusive. Here, we demonstrate that the transcription factor c-Maf is a critical controller for immunosuppressive macrophage polarization and function in cancer. c-Maf controls many M2-related genes and has direct binding sites within a conserved noncoding sequence of the Csf-1r gene and promotes M2-like macrophage-mediated T cell suppression and tumor progression. c-Maf also serves as a metabolic checkpoint regulating the TCA cycle and UDP-GlcNAc biosynthesis, thus promoting M2-like macrophage polarization and activation. Additionally, c-Maf is highly expressed in tumor-associated macrophages (TAMs) and regulates TAM immunosuppressive function. Deletion of c-Maf specifically in myeloid cells results in reduced tumor burden with enhanced antitumor T cell immunity. Inhibition of c-Maf partly overcomes resistance to anti-PD-1 therapy in a subcutaneous LLC tumor model. Similarly, c-Maf is expressed in human M2 and tumor-infiltrating macrophages/monocytes as well as circulating monocytes of human non-small cell lung carcinoma (NSCLC) patients and critically regulates their immunosuppressive activity. The natural compound β-glucan downregulates c-Maf expression on macrophages, leading to enhanced antitumor immunity in mice. These findings establish a paradigm for immunosuppressive macrophage polarization and transcriptional regulation by c-Maf and suggest that c-Maf is a potential target for effective tumor immunotherapy.

Metabolomics provides a readout of the state of metabolism in cells or tissue and their responses to external perturbations. For this reason, the approach has great potential in clinical diagnostics. Clinical metabolomics using stable isotope resolved metabolomics (SIRM) for pathway tracing represents an important new approach to obtaining metabolic parameters in human cancer subjects in situ. Here we provide an overview of the technology development of labeling from cells in culture and mouse models. The high throughput analytical methods NMR and mass spectrometry, especially Fourier transform ion cyclotron resonance, for analyzing the resulting metabolite isotopomers and isotopologues are described with examples of applications in cancer biology. Special technical considerations for clinical applications of metabolomics using stable isotope tracers are described. The whole process from concept to analysis will be exemplified by our on-going study of nonsmall cell lung cancer (NSCLC) metabolomics. This powerful new approach has already provided important new insights into metabolic adaptations in lung cancer cells, including the upregulation of anaplerosis via pyruvate carboxylation in NSCLC.

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The current diagnostic criteria for hepatoid adenocarcinoma of lung include typical acinar or papillary adenocarcinoma and a component resembling hepatocellular carcinoma and expressing a-fetoprotein (AFP). Distinguishing hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung is difficult in patients with both lung and liver masses and in patients at risk for lung and liver cancer because of smoking and viral hepatitis, respectively. We studied morphologic features of hepatoid adenocarcinoma of lung and established an immunohistochemical panel to facilitate distinction of hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung. Five cases of hepatoid adenocarcinoma of lung were stained with hematoxylin and eosin and mucicarmine for histomorphologic evaluation. The 14-marker immunohistochemical profile was established for hepatoid adenocarcinoma of lung and compared with that of hepatocellular carcinoma. Two cases of hepatoid adenocarcinoma of lung had signet-ring cell components. Three cases were pure hepatoid adenocarcinoma without components of acinar or papillary adenocarcinoma, signet-ring cells or neuroendocrine carcinoma. Like hepatocellular carcinoma, hepatoid adenocarcinoma of lung expresses CK8 (5/5), CK18 (5/5), AFP (3/5) and HepPar1 (5/5), shows cytoplasmic staining with TTF-1 (5/5) and does not express CK14 (0/5). Unlike hepatocellular carcinoma, it expresses CK5/6 (1/5), CK7 (3/5), CK19 (4/5), CK20 (1/5), HEA125 (5/5), MOC31 (5/5), monoclonal CEA (3/5) and napsin A (1/5). An immunohistochemical panel that includes a variety of cytokeratins, monoclonal CEA and EpCAM markers (HEA125 and MOC31) facilitates distinction of hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung, especially when correlated with clinical and radiologic findings. We propose modification of the current diagnostic criteria for hepatoid adenocarcinoma of lung. Tumor composition can be either pure hepatoid adenocarcinoma or hepatoid adenocarcinoma with components of typical acinar or papillary adenocarcinoma, signet-ring cells or neuroendocrine carcinoma. AFP expression is not requisite for diagnosis as long as other markers of hepatic differentiation are expressed.

Early detection of lung cancer is a key factor for increasing the survival rates of lung cancer patients. The analysis of exhaled breath is promising as a noninvasive diagnostic tool for diagnosis of lung cancer. We demonstrate the quantitative analysis of carbonyl volatile organic compounds (VOCs) and identification of lung cancer VOC markers in exhaled breath using unique silicon microreactor technology. The microreactor consists of thousands of micropillars coated with an ammonium aminooxy salt for capture of carbonyl VOCs in exhaled breath by means of oximation reactions. Captured aminooxy-VOC adducts are analyzed by nanoelectrospray Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometry (MS). The concentrations of 2-butanone, 2-hydroxyacetaldehyde, 3-hydroxy-2-butanone, and 4-hydroxyhexenal (4-HHE) in the exhaled breath of lung cancer patients (n = 97) were significantly higher than in the exhaled breath of healthy smoker and nonsmoker controls (n = 88) and patients with benign pulmonary nodules (n = 32). The concentration of 2-butanone in exhaled breath of patients (n = 51) with stages II though IV non–small cell lung cancer (NSCLC) was significantly higher than in exhaled breath of patients with stage I (n = 34). The carbonyl VOC profile in exhaled breath determined using this new silicon microreactor technology provides for the noninvasive detection of lung cancer.