bims-meluca 2019-01-20 papers

on Metabolism of non-small cell lung carcinoma

Issue of 2019–01–20
eight papers selected by
the Muñoz-Pinedo/Nadal (PReTT) lab, L’Institut d’Investigació Biomèdica de Bellvitge and Cristina Muñoz Pinedo, L’Institut d’Investigació Biomèdica de Bellvitge

Hypercapnic tumor microenvironment confers chemoresistance to lung cancer cells by reprogramming mitochondrial metabolism in vitro.
PILAR1, a novel prognostic LncRNA, reveals the presence of a unique subtype of lung adenocarcinoma patients with KEAP1 mutations.
Wogonin affects proliferation and the energy metabolism of SGC-7901 and A549 cells.
Overexpression of Ulk2 inhibits proliferation and enhances chemosensitivity to cisplatin in non-small cell lung cancer.
Genetic Variants in RUNX3, AMD1 and MSRA in the Methionine Metabolic Pathway and Survival in Non-small Cell Lung Cancer Patients.
HIF-1α and HIF-2α Differently Regulate the Radiation Sensitivity of NSCLC Cells.
Statins improve survival in patients previously treated with nivolumab for advanced non-small cell lung cancer: An observational study.
Effects of Statin Exposure and Lung Cancer Survival: A Systematic Review and Meta-Analysis.

Free Radic Biol Med. 2019 Jan 10. pii: S0891-5849(18)31303-0. [Epub ahead of print]

Hypercapnic tumor microenvironment confers chemoresistance to lung cancer cells by reprogramming mitochondrial metabolism in vitro.

Ryota Kikuchi, Yuki Iwai, Takao Tsuji, Yasutaka Watanabe, Nobuyuki Koyama, Kazuhiro Yamaguchi, Hiroyuki Nakamura, Kazutetsu Aoshiba.

  The tumor microenvironment has previously been reported to be hypercapnic (as high as ~84mmHg), although its effect on tumor cell behaviors is unknown. In this study, high CO2 levels, ranging from 5% to 15%, protected lung cancer cells from anticancer agents, such as cisplatin, carboplatin and etoposide, by suppressing apoptosis. The cytoprotective effect of a high CO2 level was independent of acidosis and was due to mitochondrial metabolic reprogramming that reduced mitochondrial respiration, as assessed by oxygen consumption, oxidative phosphorylation, mitochondrial membrane and oxidative potentials, eventually leading to reduced reactive oxidant species production. In contrast, high CO2 levels did not affect cisplatin-mediated DNA damage responses or the expression of Bcl-2 family proteins. Although high CO2 levels inhibited glycolysis, this inhibition was not mechanistically involved in high CO2-mediated reductions in mitochondrial respiration, because a high CO2 concentration inhibited isolated mitochondria. A cytoprotective effect of high CO2 levels on mitochondria DNA-depleted cells was not noted, lending support to our conclusion that high CO2 levels act on mitochondria to reduce the cytotoxicity of anticancer agents. High CO2-mediated cytoprotection was also noted in a 3D culture system. In conclusion, the hypercapnic tumor microenvironment reprograms mitochondrial respiratory metabolism causing chemoresistance in lung cancer cells. Thus, tumor hypercapnia may represent a novel target to improve chemosensitivity.

Keywords:  CO(2); Carboplatin; Cisplatin; Reactive oxygen species

DOI:  https://doi.org/10.1016/j.freeradbiomed.2019.01.014
Gene. 2019 Jan 09. pii: S0378-1119(19)30014-9. [Epub ahead of print]

PILAR1, a novel prognostic LncRNA, reveals the presence of a unique subtype of lung adenocarcinoma patients with KEAP1 mutations.

Pranjal Kumar, Seema Khadirnaikar, Sudhanshu Kumar Shukla.

  Lung Adenocarcinoma (LUAD) is the most common cause of lung cancer-related deaths. Long non-coding RNAs (LncRNAs) play an essential role in cancer development and progression. In this study, we identified PILAR1, a prognostic and overexpressed LncRNA, using multiple independent datasets of LUAD patients. Higher expression of PILAR1 was associated with survival in Dhanasekaran et al. (HR = 2.29, p-value = 0.017), TCGA (HR = 1.51, p-value = 0.017) and KM plotter (HR = 2.67, p-value ≤ 0.0001) cohorts. Mutational landscape of LUAD showed that KEAP1 mutation was exclusively present in PILAR1 expressing samples. Further, knockdown of PILAR1 significantly inhibited cell proliferation, colony formation and migration of A549 cells. Importantly, inhibition of PILAR1 made the A549 cells more sensitive to etoposide. Furthermore, pathway analysis using differentially expressed genes in PILAR1 knockdown cells compared to control cells identified enrichment of DNA repair genes suggesting towards the mechanism of PILAR1 mediated etoposide sensitivity. Taken together, we identified a prognostically robust LncRNA, PILAR1, which also regulates cell growth in lung cancer cells. PILAR1 expression identified a novel subtype of LUAD patients with the exclusive KEAP1 mutation.

Keywords:  Cell growth; Chemosensitivity; Immune cells; Long non-coding RNA (LncRNA); Lung adenocarcinoma; Prognosis

DOI:  https://doi.org/10.1016/j.gene.2018.12.060
Exp Ther Med. 2019 Jan;17(1): 911-918

Wogonin affects proliferation and the energy metabolism of SGC-7901 and A549 cells.

Shu-Jing Wang, Jian-Kai Zhao, Shuang Ren, Wei-Wei Sun, Wen-Jun Zhang, Jia-Ning Zhang.

  Many studies have focused on the identification of therapeutic targets for the treatment of certain types of cancer. Wogonin is a natural flavonoid compound that exhibits a potent anti-cancer effect. The underlying mechanism of wogonin may therefore reveal an effective way to identify novel therapeutic targets. In the current study, growth curves and MTT assays were performed to determine the effects of wogonin in human gastric cancer cells (SGC-7901) and human lung adenocarcinoma cells (A549), respectively. Changes in morphology were observed using hematoxylin and eosin (H&E) staining. The activities of key enzymes in the glycolysis and tricarboxylic acid cycle were measured using spectrophotometry. Western blot analysis was performed to determine the expression levels of hypoxia inducible factor-1α (HIF-1α) and monocarboxylate transporter-4 (MCT-4). Wogonin inhibited cell proliferation in a time- and dose-dependent manner in SGC-7901 and A549 cells. H&E staining suggested that wogonin induced cell morphology changes. In SGC-7901 cells, lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) activities and adenosine triphosphate (ATP) generation were decreased significantly by wogonin treatment compared with the untreated control. In A549 cells, wogonin significantly reduced LDH activity, but exhibited no significant effects on kinase activities or ATP generation. Furthermore, wogonin significantly decreased HIF-1α and MCT-4 protein expression in SGC-7901 cells, but not in A549 cells. The results demonstrated that wogonin inhibited the energy metabolism, cell proliferation and angiogenesis in SGC-7901 and A549 cells by negatively regulating HIF-1α and MCT-4 expression. The differential regulatory roles of wogonin in metabolism-associated enzymes in human gastric cancer and lung adenocarcinoma cells indicated its various antitumor mechanisms. The different metabolic regulatory mechanisms exhibited by wogonin in different tumor tissues should therefore be considered for antitumor therapy.

Keywords:  A549 cells; SGC-7901 cells; adenosine triphosphate; energy metabolism; enzyme; wogonin

DOI:  https://doi.org/10.3892/etm.2018.7023
Oncol Lett. 2019 Jan;17(1): 79-86

Overexpression of Ulk2 inhibits proliferation and enhances chemosensitivity to cisplatin in non-small cell lung cancer.

Hong Cheng, Ze-Tian Yang, Yu-Quan Bai, Yan-Fei Cai, Jin-Ping Zhao.

  The aim of the present study was to examine the function of unc-51 like autophagy activating kinase 2 (Ulk2) in non-small cell lung cancer (NSCLC). Western blotting was used to analyze the protein expression of Ulk2 in seven pairs of cancerous and adjacent non-cancerous NSCLC specimens. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was used to determine the mRNA expression of Ulk2 in 20 pairs of tumor and adjacent normal tissues. Two NSCLC cell lines, A549 and H460, were transfected with an Ulk2 overexpression plasmid or empty vector; cell proliferation and chemosensitivity were measured using an MTT assay, and flow cytometry and western blotting were used to evaluate apoptosis. A nude mouse tumorigenesis experiment was used to assess tumor volume in vivo, using A549 cells stably overexpressing Ulk2 and control cells. The protein expression levels of Ulk2 were significantly lower in 6/7 (85.7%) cases of NSCLC compared with in non-cancerous tissues, as determined by western blotting (P<0.05). The mRNA expression levels of Ulk2 were significantly lower in 16/20 (70.0%) NSCLC specimens compared with in non-cancerous tissues, as revealed by RT-qPCR (P<0.05). Overexpression of Ulk2 significantly inhibited the proliferation of A549 and H460 cells (P<0.05) and sensitized the NSCLC cell lines to cisplatin- and etoposide-induced inhibition of proliferation, and to cisplatin-induced apoptosis, with a significant difference identified compared with the control group (P<0.05). Overexpression of Ulk2 significantly increased basal autophagy levels in A549 and H460 cells (P<0.05). Thus, Ulk2-induced enhanced chemosensitivity was suggested to be partly mediated through increased autophagy. The overexpression of Ulk2 significantly suppressed tumor volume in vivo (P<0.05). Overexpression of Ulk2 inhibits cancer cell proliferation and enhances chemosensitivity to cisplatin in NSCLC.

Keywords:  autophagy; cell proliferation; chemosensitivity; non-small cell lung cancer; unc-51-like autophagy activating kinase 2

DOI:  https://doi.org/10.3892/ol.2018.9604
Int J Cancer. 2019 Jan 16.

Genetic Variants in RUNX3, AMD1 and MSRA in the Methionine Metabolic Pathway and Survival in Non-small Cell Lung Cancer Patients.

Ka Chen, Hongliang Liu, Zhensheng Liu, Sheng Luo, Edward F Patz, Patricia G Moorman, Li Su, Sipeng Shen, David C Christiani, Qingyi Wei.

  Abnormal methionine dependence in cancer cells has led to methionine restriction as a potential therapeutic strategy. We hypothesized that genetic variants involved in methionine-metabolic genes are associated with survival in non-small cell lung cancer (NSCLC) patients. Therefore, we investigated associations of 16,378 common single-nucleotide polymorphisms (SNPs) in 97 methionine-metabolic pathway genes with overall survival (OS) in NSCLC patients using genotyping data from two published genome-wide association study (GWAS) datasets. In the single-locus analysis, 1,005 SNPs were significantly associated with NSCLC OS (P < 0.05 and false-positive report probability < 0.2) in the discovery dataset. Three SNPs (RUNX3 rs7553295G>T, AMD1 rs1279590G>A and MSRA rs73534533C>A) were replicated in the validation dataset and their meta-analysis showed that adjusted hazards ratio [HR] of 0.82 [95% confidence interval (CI) =0.75-0.89] and Pmeta =2.86 x 10-6 , 0.81 (0.73-0.91) and Pmeta =4.63 x 10-4 , and 0.77 (0.68-0.89) and Pmeta =2.07 x 10-4 , respectively). A genetics score of protective genotypes of these three SNPs revealed an increased OS in a dose-response manner (Ptrend <.0001). Further expression quantitative trait loci (eQTL) analysis showed significant associations between these genotypes and gene mRNA expression levels. Moreover, differential expression analysis further supported a tumor-suppressive effect of MSRA, with lower mRNA levels in both lung squamous carcinoma and adenocarcinoma (P <.0001 and <.0001, respectively) than in adjacent normal tissues. Additionally, low mutation rates of these three genes indicated the critical roles of these functional SNPs in cancer progression. Taken together, these genetic variants of methionine-metabolic pathway genes may be promising predictors of survival in NSCLC patients. This article is protected by copyright. All rights reserved.

Keywords:  Genome-wide association study; Methionine; Non-small cell lung cancer; Single-nucleotide polymorphism; Survival

DOI:  https://doi.org/10.1002/ijc.32128
Cells. 2019 Jan 12. pii: E45. [Epub ahead of print]8(1):

HIF-1α and HIF-2α Differently Regulate the Radiation Sensitivity of NSCLC Cells.

Eloy Moreno Roig, Arjan J Groot, Ala Yaromina, Tessa C Hendrickx, Lydie M O Barbeau, Lorena Giuranno, Glenn Dams, Jonathan Ient, Veronica Olivo Pimentel, Marike W van Gisbergen, Ludwig J Dubois, Marc A Vooijs.

  The hypoxia-inducible transcription factors (HIF)-1/2α are the main oxygen sensors which regulate the adaptation to intratumoral hypoxia. The aim of this study was to assess the role of the HIF proteins in regulating the radiation response of a non-small cell lung cancer (NSCLC) in vitro model. To directly assess the unique and overlapping functions of HIF-1α and HIF-2α, we use CRISPR gene-editing to generate isogenic H1299 non-small cell lung carcinoma cells lacking HIF-1α, HIF-2α or both. We found that in HIF1 knockout cells, HIF-2α was strongly induced by hypoxia compared to wild type but the reverse was not seen in HIF2 knockout cells. Cells lacking HIF-1α were more radiation resistant than HIF2 knockout and wildtype cells upon hypoxia, which was associated with a reduced recruitment of γH2AX foci directly after irradiation and not due to differences in proliferation. Conversely, double-HIF1/2 knockout cells were most radiation sensitive and had increased γH2AX recruitment and cell cycle delay. Compensatory HIF-2α activity in HIF1 knockout cells is the main cause of this radioprotective effect. Under hypoxia, HIF1 knockout cells uniquely had a strong increase in lactate production and decrease in extracellular pH. Using genetically identical HIF-α isoform-deficient cells we identified a strong radiosensitizing of HIF1, but not of HIF2, which was associated with a reduced extracellular pH and reduced glycolysis.

Keywords:  HIF; hypoxia; metabolism; radiotherapy

DOI:  https://doi.org/10.3390/cells8010045
Mol Clin Oncol. 2019 Jan;10(1): 137-143

Statins improve survival in patients previously treated with nivolumab for advanced non-small cell lung cancer: An observational study.

Miwako Omori, Yusuke Okuma, Taiki Hakozaki, Yukio Hosomi.

  There are a number of suggested predictive factors of nivolumab for non-small cell lung cancer (NSCLC), however, there is not enough evidence to determine a single factor that can predict the efficacy of nivolumab. As the progress of biomarkers for cancer treatment is improving, it has been speculated that certain clinical factors serve an important role when predicting the outcome of chemotherapy. A total of 67 patients treated with nivolumab for NSCLC from 2016-2017 were prospectively investigated. Age, sex, the Eastern Cooperative Oncology Group Performance Status, histology, epidermal growth factor receptor (EGFR) mutation, history of chemotherapy, smoking status, use of statins, use of fibrates, use of dipeptidyl peptidase-4 (DPP-4) inhibitors, and use of metformin were examined as clinical factors. Statistical analyses were performed using the Kaplan-Meier method and Cox regression adjusted for risk factors and the tumor response of 67 patients was assessed. The patients had a median age of 67 years (range, 36-87 years), and 46 males and 21 females were enrolled; performance status 0/1 was 59. Cases were categorized as adenocarcinoma (n=41), squamous cell carcinoma (n=17) and other (n=9). A total of 13 patients (19.4%) had EGFR mutations. These clinical factors were not statistically significant in overall survival (OS). Clinical laboratory findings, complications and use of medical agents including antidiabetes mellitus or lipidemia were also analyzed. Statins exhibited statistical significance for response (P=0.02). Time-to-treatment failure (TTF) in statin-use group was not reached [95% confidence interval (CI): 1.9-not reached] and was 4.0 months (95% CI: 2.0-5.4) in the non-statin group (P=0.039). The median OS in statin-use group was not reached (95% CI: 8.7-not reached) and was 16.5 months (95% CI: 7.5-not reached) in the non-statin group (P=0.058). NSCLC patients previously treated with nivolumab who were administered statins exhibited an increased response rate and longer TTF. This response was not statistically significant in OS.

Keywords:  nivolumab; non-small cell lung cancer; prognosis; statin

DOI:  https://doi.org/10.3892/mco.2018.1765
Pharmacol Res. 2019 Jan 11. pii: S1043-6618(18)31870-X. [Epub ahead of print]

Effects of Statin Exposure and Lung Cancer Survival: A Systematic Review and Meta-Analysis.

Yafei Chen, Xiaoli Li, Rui Zhang, Yuhong Xia, Zhuo Shao, Zubing Mei.

  Statin exposure has been reported to improve survival in several cancers. However, studies evaluating the association between statins and prognostic outcomes in patients with lung cancer are conflicting and heterogeneous. Pubmed, EMBASE and reference lists of included studies were searched to identify studies investigating the association between statin exposure and lung cancer prognosis. The primary outcome measure was overall survival (OS) and secondary ones included cancer-specific survival (CSS) and recurrence-free survival (RFS). Hazard ratios (HRs) with 95% confidence intervals (95% CIs) of these outcomes were pooled using random-effects models. Thirteen studies with data from 99,297 individuals satisfying the inclusion criteria were identified. Studies were ranked to be at low to moderate risk of bias. Meta-analysis showed that statin exposure was significantly associated with improved OS (pooled HR 0.79, 95% CI 0.72 to 0.86), CSS (pooled HR 0.83, 95% CI 0.77 to 0.89) and RFS (pooled HR 0.85, 95% CI 0.81 to 0.89). Subgroup analyses showed that statin users after diagnosis of lung cancer had more survival benefit for OS (HR 0.68, 95% CI 0.51 to 0.92) than those before diagnosis (HR 0.86, 95% CI 0.81 to 0.90) and current users (HR 0.79, 95% CI 0.62 to 1.02) (P for interaction < 0.001). Besides, statin users were likely to have more survival benefits in stage IV lung cancer patients (HR 0.77, 95% CI 0.74 to 0.79) than in mixed stage (I-IV or I-III) patients (P for interaction = 0.004). Statin exposure is associated with significantly improved survival in patients with lung cancer. Future studies are warranted to further demonstrate the therapeutic role of statins in specific lung cancer patients.

Keywords:  HMG-CoA reductase inhibitor; lung cancer; meta-analysis; mortality; prognosis; statins

DOI:  https://doi.org/10.1016/j.phrs.2019.01.016