bims-meluca Biomed News
on Metabolism of non-small cell lung carcinoma
Issue of 2019‒12‒15
ten papers selected by
Cristina Muñoz Pinedo
L’Institut d’Investigació Biomèdica de Bellvitge

  1. Cell Metab. 2019 Nov 28. pii: S1550-4131(19)30619-9. [Epub ahead of print]
      Rewiring of metabolic pathways is a hallmark of tumorigenesis as cancer cells acquire novel nutrient dependencies to support oncogenic growth. A major genetic subtype of lung adenocarcinoma with KEAP1/NRF2 mutations, which activates the endogenous oxidative stress response, undergoes significant metabolic rewiring to support enhanced antioxidant production. We demonstrate that cancers with high antioxidant capacity exhibit a general dependency on exogenous non-essential amino acids (NEAAs) that is driven by the Nrf2-dependent secretion of glutamate through system xc- (XCT), which limits intracellular glutamate pools that are required for NEAA synthesis. This dependency can be therapeutically targeted by dietary restriction or enzymatic depletion of individual NEAAs. Importantly, limiting endogenous glutamate levels by glutaminase inhibition can sensitize tumors without alterations in the Keap1/Nrf2 pathway to dietary restriction of NEAAs. Our findings identify a metabolic strategy to therapeutically target cancers with genetic or pharmacologic activation of the Nrf2 antioxidant response pathway by restricting exogenous sources of NEAAs.
    Keywords:  Keap1; NRF2; amino acid synthesis; asparaginase; glutamate; glutaminase; lung cancer; metabolism; non-essential amino acids; oxidative stress; system x(c)(−)
  2. Cancer Sci. 2019 Dec 11.
      Aberrant activation of NRF2 has been known as a critical prognostic factor that drives the malignant progression of various cancers. Cancer cells with persistent NRF2 activation heavily rely on NRF2 activity for therapeutic resistance and aggressive tumourigenic capacity. To clarify metabolic features of NRF2-activated lung cancers, we conducted targeted metabolomic (T-Met) and global metabolomic (G-Met) analyses of non-small-cell lung cancer (NSCLC) cell lines in combination with exome and transcriptome analyses. Exome analysis of 88 cell lines (49 adenocarcinoma, 14 large cell carcinoma, 15 squamous cell carcinoma and 10 others) identified non-synonymous mutations in the KEAP1, NRF2, and CUL3 genes. Judging from the elevated expression of NRF2 target genes, these mutations are expected to result in the constitutive stabilization of NRF2. 52 NSCLC cell lines (29 adenocarcinoma, 10 large cell carcinoma, 9 squamous cell carcinoma and 4 others) out of the 88 cell lines were subjected to T-Met analysis. Classification of the 52 cell lines into three groups according to the NRF2 target gene expression enabled us to draw typical metabolomic signatures induced by NRF2 activation. 18 NSCLC cell lines (14 adenocarcinoma, 2 large cell carcinoma, 1 squamous cell carcinoma and 1 others) were further chosen from the 52 cell lines for G-Met and detailed transcriptome analyses. G-Met analysis of their culture supernatants revealed novel metabolites associated with NRF2 activity, which may be potential diagnostic biomarkers of NRF2 activation. This study also provides useful information for the exploration of new metabolic nodes for selective toxicity towards NRF2-activated NSCLC.
    Keywords:  Culture supernatant; NRF2; metabolites; metabolome; non-small-cell lung cancer
  3. Cancers (Basel). 2019 Dec 05. pii: E1945. [Epub ahead of print]11(12):
      Glutamate-ammonia ligase (GLUL) is important for acid-base homeostasis, ammonia detoxification, cell signaling, and proliferation. Here, we reported that GLUL ablation conferred resistance to several anticancer drugs in specific cancer cell lines while leaving other cell lines non-resistant to the same drugs. To understand the biochemical mechanics supporting this drug resistance, we compared drug-resistant GLUL knockout (KO) A549 non-small-cell lung carcinoma (NSCLC) cells with non-resistant GLUL KO H1299 NSCLC cells and found that the resistant A549 cells, to a larger extent, depended on exogenous glucose for proliferation. As GLUL activity is linked to the tricarboxylic acid (TCA) cycle via reversed glutaminolysis, we probed carbon flux through both glycolysis and TCA pathways by means of 13C5 glutamine, 13C5 glutamate, and 13C6 glucose tracing. We observed increased labeling of malate and aspartate in A549 GLUL KO cells, whereas the non-resistant GLUL KO H1299 cells displayed decreased 13C-labeling. The malate and aspartate shuttle supported cellular NADH production and was associated with cellular metabolic fitness. Inhibition of the malate-aspartate shuttle with aminooxyacetic acid significantly impacted upon cell viability with an IC50 of 11.5 μM in resistant GLUL KO A549 cells compared to 28 μM in control A549 cells, linking resistance to the malate-aspartate shuttle. Additionally, rescuing GLUL expression in A549 KO cells increased drug sensitivity. We proposed a novel metabolic mechanism in cancer drug resistance where the increased capacity of the malate-aspartate shuttle increased metabolic fitness, thereby facilitating cancer cells to escape drug pressure.
    Keywords:  GLUL; LC-MS; NSCLC; drug resistance; glutamine; glycolysis; metabolism; metabolomics; targeted metabolomics
  4. Cancer Med. 2019 Dec 12.
      BACKGROUND: Previous studies indicated that type 2 diabetes mellitus (T2DM) is related to an increased lung cancer risk, but its role in the prognosis of NSCLC remains conflicting. This study investigated the impact of blood glucose control on the outcomes in NSCLC patients with T2DM treated with platinum-based doublets.METHODS: Clinicopathological and survival data from 191 T2DM patients with advanced NSCLC, who received platinum-based chemotherapy, were retrospectively analyzed. Based on the blood glucose conditions during chemotherapy, patients were classified into poor (n = 84) and good control (n = 107) groups. Progression-free survival (PFS) was assessed using the Kaplan-Meier method.
    RESULTS: The median PFS among patients with good glycemic control [197.0 (95% CI: 136.3-257.7) days] was longer than that among those with poor control [132.0 (95% CI: 112.5-151.5) days] (P = .0003). Further subgroup analysis of lung squamous carcinoma and adenocarcinoma patients showed that the median PFS of the good control group was also significantly longer than that of the poor control group [179.0 (95% CI: 78.4-279.6) days vs 125.0 (95% CI: 110.9-139.1) days, P = .0014; 197.0 (95% CI: 124.3-269.7) days vs 154.0 (95% CI: 129.9-178.1) days, P = .0359; respectively]. The incidence rates of side effects were similar among patients with good glycemic control and those with poor glycemic control (all P > .05).
    CONCLUSIONS: Satisfactory glycemic control during platinum-based chemotherapy might provide a survival benefit to T2DM patients with NSCLC. Further studies are warranted to confirm our findings.
    Keywords:  glycemic control level; non-small cell lung cancer; platinum-based chemotherapy; progression-free survival; type 2 diabetes mellitus
  5. Am J Transl Res. 2019 ;11(11): 6860-6876
      Platinum-based chemotherapy is still widely applied for the treatment of advanced non-small cell lung cancer (NSCLC). However, acquired chemoresistance compromises the curative effect of this drug. In this study, we found that glucose-6-phosphate dehydrogenase (G6PD), a critical enzyme of the pentose phosphate pathway, contributed to cisplatin resistance in NSCLC. The experimental results showed that transforming growth factor beta 1 (TGFβ1) increased the expression of G6PD by activating the forkhead box protein M1-high mobility group AT-hook 1-G6PD (FOXM1-HMGA1-G6PD) transcriptional regulatory pathway, in which TGFβ1 inhibited the ubiquitination and degradation of FOXM1 protein. Additionally, HMGA1 induced TGFβ1 expression, and neutralized TGFβ1 in the culture medium downregulated HMGA1 levels, suggesting the existence of a TGFβ1-FOXM1-HMGA1-TGFβ1 positive feedback loop and its role in maintaining G6PD expression. Further investigations showed that exogenous TGFβ1 enhanced the cisplatin resistance of NSCLC cells, while disrupting the FOXM1-HMGA1-G6PD pathway, thereby sensitizing the cells to cisplatin. Consistently, the TGFβ1-FOXM1-HMGA1-G6PD axis was confirmed in NSCLC tissues, and overactivation of this axis predicted poor survival in NSCLC patients. Collectively, the results of this study demonstrate that the TGFβ1-FOXM1-HMGA1-TGFβ1 positive feedback loop plays a crucial role in the cisplatin resistance of NSCLC by upregulating the expression of G6PD, providing a potential therapeutic target to restore chemosensitivity in cisplatin-resistant NSCLC.
    Keywords:  Non-small-cell lung cancer (NSCLC); cisplatin resistance; forkhead box protein M1 (FOXM1); glucose-6-phosphate dehydrogenase (G6PD); high-mobility group A1 (HMGA1); transforming growth factor β1 (TGFβ1)
  6. Rev Esp Med Nucl Imagen Mol. 2019 Dec 06. pii: S2253-654X(19)30193-3. [Epub ahead of print]
      OBJECTIVE: The present study evaluates the prognostic value of metabolic parameters related to the primary tumor on pretreatment 18F FDG PET/CT in patients with advanced stage lung adenocarcinoma.MATERIAL AND METHODS: This retrospective study included 258 patients with advanced stage lung adenocarcinoma who underwent pretreatment PET/CT scan, and for whom epidermal growth factor receptor (EGFR)/anaplastic lymphoma kinase (ALK) status was available. The maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) related to the primary tumor at the baseline PET and various clinical factors were recorded. The relation between these factors and overall survival (OS) and progression-free survival (PFS) was evaluated.
    RESULTS: The study included 258 patients with stage IIIB-IV lung adenocarcinoma (72 female, 186 male, mean age 60.4±10.4 years), 210 of which died and 243 of which progressed at the time of analysis. The median OS and PFS of the patients were 16±1.9 and 5±0.5 months, respectively. The present study revealed no significant relation between OS or PFS and gender, smoking status, presence of distant metastasis, age and tumor size. There was no significant difference in the OS and PFS of patients testing negative for EGFR mutations/ALK rearrangements and those testing positive for both or either of the EGFR mutations and ALK rearrangements. OS was significantly longer in patients with low MTV(p=0.011) and those with low TLG(p=0.012) than high ones. However, no significant relation was found between SUVmax and SUVmean values and OS, and between all PET parameters and PFS.
    CONCLUSION: MTV and TLG reflecting the metabolic tumor burden can predict OS in patients with advanced lung adenocarcinoma.
    Keywords:  Cáncer pulmonar de células no pequeñas; FDG PET/CT; FDG PET/TC; MTV; Nonsmall cell lung cancer; Prognosis; Pronóstico; SUVmax; SUVmáx; Supervivencia; Survival; TLG
  7. Cancers (Basel). 2019 Dec 03. pii: E1925. [Epub ahead of print]11(12):
      BACKGROUND: Muscle mass and physical function (PF) are common co-primary endpoints in cancer cachexia trials, but there is a lack of data on how these outcomes interact over time. The aim of this secondary analysis of data from a trial investigating multimodal intervention for cancer cachexia ( NCT01419145) is to explore whether changes in muscle mass and PF are associated with weight loss and cachexia status at baseline.METHODS: Secondary analysis was conducted using data from a phase II randomized controlled trial including 46 patients with stage III-IV non-small cell lung cancer (n = 26) or inoperable pancreatic cancer (n = 20) due to commence chemotherapy. Cachexia status at baseline was classified according to international consensus. Muscle mass (assessed using computed tomography (CT)) and PF outcomes, i.e., Karnofsky performance status (KPS), self-reported PF (self-PF), handgrip strength (HGS), 6-minute walk test (6MWT), and physical activity (PA), were measured at baseline and after six weeks.
    RESULTS: When compared according to cachexia status at baseline, patients with no/pre-cachexia had a mean loss of muscle mass (-5.3 cm2, p = 0.020) but no statistically significant change in PF outcomes. Patients with cachexia also lost muscle mass but to a lesser extent (-2.8 cm2, p = 0.146), but demonstrated a statistically significant decline in PF; KPS (-3.8 points, p = 0.030), self-PF (-8.8 points, p = 0.027), and HGS (-2.7 kg, p = 0.026).
    CONCLUSIONS: Weight loss history and cachexia status at baseline are of importance if one aims to detect changes in PF outcomes in cancer cachexia trials. To improve the use of co-primary endpoints that include PF in future trials, outcomes that have the potential to detect change relative to weight loss should be investigated further.
    Keywords:  cachexia; cancer; endpoints; grip strength; muscle mass; physical performance; weight loss
  8. J Cachexia Sarcopenia Muscle. 2019 Dec 11.
      BACKGROUND: Cachexia, highly prevalent in patients with non-small cell lung cancer (NSCLC), impairs quality of life and is associated with reduced tolerance and responsiveness to cancer therapy and decreased survival. MicroRNAs (miRNAs) are small non-coding RNAs that play a central role in post-transcriptional gene regulation. Changes in intramuscular levels of miRNAs have been implicated in muscle wasting conditions. Here, we aimed to identify miRNAs that are differentially expressed in skeletal muscle of cachectic lung cancer patients to increase our understanding of cachexia and to allow us to probe their potential as therapeutic targets.METHODS: A total of 754 unique miRNAs were profiled and analysed in vastus lateralis muscle biopsies of newly diagnosed treatment-naïve NSCLC patients with cachexia (n = 8) and age-matched and sex-matched healthy controls (n = 8). miRNA expression analysis was performed using a TaqMan MicroRNA Array. In silico network analysis was performed on all significant differentially expressed miRNAs. Differential expression of the top-ranked miRNAs was confirmed using reverse transcription-quantitative real-time PCR in an extended group (n = 48) consisting of NSCLC patients with (n = 15) and without cachexia (n = 11) and healthy controls (n = 22). Finally, these miRNAs were subjected to univariate and multivariate Cox proportional hazard analysis using overall survival and treatment-induced toxicity data obtained during the follow-up of this group of patients.
    RESULTS: We identified 28 significant differentially expressed miRNAs, of which five miRNAs were up-regulated and 23 were down-regulated. In silico miRNA-target prediction analysis showed 158 functional gene targets, and pathway analysis identified 22 pathways related to the degenerative or regenerative processes of muscle tissue. Subsequently, the expression of six top-ranked miRNAs was measured in muscle biopsies of the entire patient group. Five miRNAs were detectable with reverse transcription-quantitative real-time PCR analysis, and their altered expression (expressed as fold change, FC) was confirmed in muscle of cachectic NSCLC patients compared with healthy control subjects: miR-424-5p (FC = 4.5), miR-424-3p (FC = 12), miR-450a-5p (FC = 8.6), miR-144-5p (FC = 0.59), and miR-451a (FC = 0.57). In non-cachectic NSCLC patients, only miR-424-3p was significantly increased (FC = 5.6) compared with control. Although the statistical support was not sufficient to imply these miRNAs as individual predictors of overall survival or treatment-induced toxicity, when combined in multivariate analysis, miR-450-5p and miR-451a resulted in a significant stratification between short-term and long-term survival.
    CONCLUSIONS: We identified differentially expressed miRNAs putatively involved in lung cancer cachexia. These findings call for further studies to investigate the causality of these miRNAs in muscle atrophy and the mechanisms underlying their differential expression in lung cancer cachexia.
    Keywords:  AtromiRs; Cancer cachexia; NSCLC; Skeletal muscle; miRNAs
  9. Sci Rep. 2019 Dec 10. 9(1): 18699
      Most cancer cells rely on glycolysis to generate ATP, even when oxygen is available. However, merely inhibiting the glycolysis is insufficient for the eradication of cancer cells. One main reason for this is that cancer cells have the potential to adapt their metabolism to their environmental conditions. In this study, we investigated how cancer cells modify their intracellular metabolism when glycolysis is suppressed, using PANC-1 pancreatic cancer cells and two other solid tumor cell lines, A549 and HeLa. Our study revealed that glycolytically suppressed cells upregulated mitochondrial function and relied on oxidative phosphorylation (OXPHOS) to obtain the ATP necessary for their survival. Dynamic changes in intracellular metabolic profiles were also observed, reflected by the reduced levels of TCA cycle intermediates and elevated levels of most amino acids. Glutamine and glutamate were important for this metabolic reprogramming, as these were largely consumed by influx into the TCA cycle when the glycolytic pathway was suppressed. During the reprogramming process, activated autophagy was involved in modulating mitochondrial function. We conclude that upon glycolytic suppression in multiple types of tumor cells, intracellular energy metabolism is reprogrammed toward mitochondrial OXPHOS in an autophagy-dependent manner to ensure cellular survival.
  10. Br J Cancer. 2019 Dec 10.
      Malignant pleural mesothelioma (MPM) is a rare malignancy of mesothelial cells with increasing incidence, and in many cases, dismal prognosis due to its aggressiveness and lack of effective therapies. Environmental and occupational exposure to asbestos is considered the main aetiological factor for MPM. Inhaled asbestos fibres accumulate in the lungs and induce the generation of reactive oxygen species (ROS) due to the presence of iron associated with the fibrous silicates and to the activation of macrophages and inflammation. Chronic inflammation and a ROS-enriched microenvironment can foster the malignant transformation of mesothelial cells. In addition, MPM cells have a highly glycolytic metabolic profile and are positive in 18F-FDG PET analysis. Loss-of-function mutations of BRCA-associated protein 1 (BAP1) are a major contributor to the metabolic rewiring of MPM cells. A subset of MPM tumours show loss of the methyladenosine phosphorylase (MTAP) locus, resulting in profound alterations in polyamine metabolism, ATP and methionine salvage pathways, as well as changes in epigenetic control of gene expression. This review provides an overview of the perturbations in metabolism and ROS homoeostasis of MPM cells and the role of these alterations in malignant transformation and tumour progression.