Browsing by Subject "glutamine"

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    Genetic variants in glutamine metabolic pathway genes predict cutaneous melanoma‐specific survival
    (Wiley, 2019-11) Chen, Ka; Liu, Hongliang; Liu, Zhensheng; Bloomer, Wendy; Amos, Christopher I.; Lee, Jeffrey E.; Li, Xin; Nan, Hongmei; Wei, Qingyi; Epidemiology, School of Public Health
    Glutamine dependence is a unique metabolic defect seen in cutaneous melanoma (CM), directly influencing the treatment and prognosis. Here, we investigated the associations between 6025 common single‐nucleotide polymorphisms (SNPs) in 77 glutamine metabolic pathway genes with CM‐specific survival (CMSS) using genotyping datasets from two published genome‐wide association studies (GWASs). In the single‐locus analysis, 76 SNPs were found to be significantly associated with CMSS (P < .050, false‐positive report probability < 0.2 and Bayesian false discovery probability < 0.8) in the discovery dataset, of which seven SNPs were replicated in the validation dataset and three SNPs (HAL rs17676826T > C, LGSN rs12663017T > A, and NOXRED1 rs8012548A > G) independently predicted CMSS, with an effect‐allele attributed adjusted hazards ratio of 1.52 (95% confidence interval = 1.19‐1.93) and P < .001, 0.68 (0.54‐0.87) and P = .002 and 0.62 (0.46‐0.83) and P = .002, respectively. The model including the number of unfavorable genotypes (NUGs) of these three SNPs and covariates improved the five‐year CMSS prediction (P = .012) than the one with other covariates only. Further expression quantitative trait loci (eQTL) analysis found that the LGSN rs12663017 A allele was significantly associated with increased messenger RNA (mRNA) expression levels (P = 8.89 × 10 −11) in lymphoblastoid cell lines of the 1000 Genomes Project database. In the analysis of the genotype tissue expression (GTEx) project datasets, HAL rs17676826 C and NOXRED1 rs8012548 G alleles were significantly associated with their mRNA expression levels in sun‐exposed skin of the lower leg (P = 6.62 × 10−6 and 1.37 × 10−7, respectively) and in sun‐not‐exposed suprapubic skin (P < .001 and 1.43 × 10−8, respectively). Taken together, these genetic variants of glutamine‐metabolic pathway genes may be promising predictors of survival in patients with CM.
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    Glucose-independent Acetate Metabolism Promotes Melanoma Cell Survival and Tumor Growth
    (American Society for Biochemistry and Molecular Biology, 2016-10-14) Lakhter, Alexander J.; Hamilton, James; Konger, Raymond L.; Brustovetsky, Nickolay; Broxmeyer, Hal E.; Naidu, Samisubbu R.; Microbiology and Immunology, School of Medicine
    Tumors rely on multiple nutrients to meet cellular bioenergetics and macromolecular synthesis demands of rapidly dividing cells. Although the role of glucose and glutamine in cancer metabolism is well understood, the relative contribution of acetate metabolism remains to be clarified. We show that glutamine supplementation is not sufficient to prevent loss of cell viability in a subset of glucose-deprived melanoma cells, but synergizes with acetate to support cell survival. Glucose-deprived melanoma cells depend on both oxidative phosphorylation and acetate metabolism for cell survival. Acetate supplementation significantly contributed to maintenance of ATP levels in glucose-starved cells. Unlike acetate, short chain fatty acids such as butyrate and propionate failed to prevent loss of cell viability from glucose deprivation. In vivo studies revealed that in addition to nucleo-cytoplasmic acetate assimilating enzyme ACSS2, mitochondrial ACSS1 was critical for melanoma tumor growth in mice. Our data indicate that acetate metabolism may be a potential therapeutic target for BRAF mutant melanoma.