glutaminase and Adenocarcinoma

Pancreatic adenocarcinoma is a leading cause of cancer mortality in western countries with a uniformly poor prognosis. Unfortunately, there has been little in the way of novel therapeutics for this malignancy over the last several decades. Derangements in metabolic circuitry favoring excess glycolysis are increasingly recognized as a key hallmark of cancer.. The role of alterations in glutamine metabolism in pancreatic tumor progression has been elucidated in animal models and human cells lines, and there has been considerable interest in exploiting these aberrations for the treatment of pancreatic cancer. Other strategies targeting NQO1/GLS1 inhibition, NAD+ synthesis, and TCA cycle intermediates are being actively studied in the clinic. Aberrant metabolism in pancreatic cancer poses a unique therapeutic strategy. We review preclinical and clinical studies looking to exploit alterations in the metabolic circuitry of pancreatic cancer.

Topics: Acrylamides; Adenocarcinoma; Antineoplastic Agents; Citric Acid Cycle; Glutaminase; Glutamine; Humans; Mitochondria; Molecular Targeted Therapy; NAD; NAD(P)H Dehydrogenase (Quinone); Pancreatic Neoplasms; Piperidines

Colon cancer is a highly anabolic entity with upregulation of glycolysis, glutaminolysis, and de novo synthesis of fatty acids, which also induces a hypercatabolic state in the patient. The blockade of either cancer anabolism or host catabolism has been previously proven to be a successful anticancer experimental treatment. However, it is still unclear whether the simultaneous blockade of both metabolic counterparts can limit malignant survival and the energetic consequences of such an approach. In this chapter, by using the CT26.WT murine colon adenocarcinoma cell line as a model of study, we provide a method to simultaneously perform a pharmacological blockade of tumor anabolism and host catabolism, as a feasible therapeutic approach to treat cancer, and to limit its energetic supply.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Colonic Neoplasms; Diazooxonorleucine; Drug Screening Assays, Antitumor; Fatty Acid Synthase, Type I; Fatty Acids; Female; Glutaminase; Glutamine; Glycolysis; Hexokinase; Indazoles; Mice; Mice, Inbred BALB C; Molecular Targeted Therapy; Orlistat; Smegmamorpha

Treating KRAS-mutant lung adenocarcinoma (LUAD) remains a major challenge in cancer treatment given the difficulties associated with directly inhibiting the KRAS oncoprotein. One approach to addressing this challenge is to define mutations that frequently co-occur with those in KRAS, which themselves may lead to therapeutic vulnerabilities in tumors. Approximately 20% of KRAS-mutant LUAD tumors carry loss-of-function mutations in the KEAP1 gene encoding Kelch-like ECH-associated protein 1 (refs. 2, 3, 4), a negative regulator of nuclear factor erythroid 2-like 2 (NFE2L2; hereafter NRF2), which is the master transcriptional regulator of the endogenous antioxidant response. The high frequency of mutations in KEAP1 suggests an important role for the oxidative stress response in lung tumorigenesis. Using a CRISPR-Cas9-based approach in a mouse model of KRAS-driven LUAD, we examined the effects of Keap1 loss in lung cancer progression. We show that loss of Keap1 hyperactivates NRF2 and promotes KRAS-driven LUAD in mice. Through a combination of CRISPR-Cas9-based genetic screening and metabolomic analyses, we show that Keap1- or Nrf2-mutant cancers are dependent on increased glutaminolysis, and this property can be therapeutically exploited through the pharmacological inhibition of glutaminase. Finally, we provide a rationale for stratification of human patients with lung cancer harboring KRAS/KEAP1- or KRAS/NRF2-mutant lung tumors as likely to respond to glutaminase inhibition.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Clustered Regularly Interspaced Short Palindromic Repeats; Genes, ras; Glutaminase; Glutamine; Humans; Hydrolysis; Kelch-Like ECH-Associated Protein 1; Lung Neoplasms; Mice

Cancer cells remodel their metabolic programmes to meet the requirements of rapid proliferation. Glutaminase (GLS1) is a mitochondrial enzyme that converts glutamine to glutamate. Our aim was to investigate, for the first time, GLS1 protein expression in colorectal cancer and to evaluate its clinical significance. Immunohistochemical analysis was performed on tissue microarrays containing pairs of cancer and adjacent normal tissues from colorectal cancer patients (n=257). The expression of GLS1 protein in normal colonic tissues and colorectal cancer was measured by western blotting. Proliferation and cell death were evaluated in colorectal cancer cell lines after GLS1 inhibitor treatment. Compared with normal tissues (18.15%), we observed that the expression of GLS1 increased significantly in colorectal cancer (80.24%; P<0.0001) by immunohistochemical analysis, and the elevation of GLS1 protein expression levels in fresh colorectal cancer samples versus normal colonic tissues were also observed by western blotting. Furthermore, GLS1 expression levels were significantly associated with deeper tumour infiltration (P=0.0002), and the pathological pattern of tubular adenocarcinoma (p=0.0008). In addition, treatment with the GLS1 inhibitor suppressed proliferation and induced apoptosis in HT29 and SW480 cell lines. These results suggest that the expression of GLS1 is upregulated and correlates with clinicopathological factors in colorectal cancer. GLS1 exhibits functional importance in colon cancer tumorigenesis. Moreover, GLS1 may serve as a target for colorectal cancer therapy.

Topics: Adenocarcinoma; Aged; Blotting, Western; Colorectal Neoplasms; Female; Glutaminase; Humans; Immunohistochemistry; Male; Microscopy, Fluorescence; Middle Aged; Tissue Array Analysis; Up-Regulation

The transcription factor p63 is critical for many biological processes, including development and maintenance of epidermal tissues and tumorigenesis. Here, we report that the TAp63 isoforms regulate cell metabolism through the induction of the mitochondrial glutaminase 2 (GLS2) gene both in primary cells and tumor cell lines. By ChIP analysis and luciferase assay, we confirmed that TAp63 binds directly to the p53/p63 consensus DNA binding sequence within the GLS2 promoter region. Given the critical role of p63 in epidermal differentiation, we have investigated the regulation of GLS2 expression during this process. GLS2 and TAp63 expression increases during the in vitro differentiation of primary human keratinocytes, and depletion of GLS2 inhibits skin differentiation both at molecular and cellular levels. We found that GLS2 and TAp63 expression are concomitantly induced in cancer cells exposed to oxidative stresses. siRNA-mediated depletion of GLS2 sensitizes cells to ROS-induced apoptosis, suggesting that the TAp63/GLS2 axis can be functionally important as a cellular antioxidant pathway in the absence of p53. Accordingly, we found that GLS2 is upregulated in colon adenocarcinoma. Altogether, our findings demonstrate that GLS2 is a bona fide TAp63 target gene, and that the TAp63-dependent regulation of GLS2 is important for both physiological and pathological processes.

Topics: Adenocarcinoma; Apoptosis; Cell Differentiation; Cell Line, Tumor; Colonic Neoplasms; Cytoprotection; DNA Damage; Glutaminase; Histone Deacetylase Inhibitors; Humans; Keratinocytes; Reactive Oxygen Species; Skin; Stress, Physiological; Transcription Factors; Tumor Suppressor Proteins; Up-Regulation

Glutaminase, the principal enzyme of glutamine hydrolysis, breaks down glutamine to supply energy and intermediates for cell growth and is present in high concentrations in replicating tissues such as intestinal epithelium and malignant tumors. In the host with cancer, glutaminase activity in the gut mucosa diminishes as the tumor grows, but the regulation of this response is unknown. Because cytokines may regulate the altered glutamine metabolism that is characteristic of the host with cancer, we studied the effects of cytokines on gut mucosal glutaminase expression in vitro using the human enterocytic Caco-2 cell line.. Differentiated confluent cells were incubated with interleukin (IL)-1, IL-6, tumor necrosis factor, or interferon-gamma (IFN-gamma). After a 12-h incubation, glutaminase-specific activity and kinetic parameters (maximal enzyme activity [Vmax] and enzyme affinity [Km]) were determined. Glutaminase protein concentration was determined by Western blot analysis using a rabbit antirat polyclonal antibody. Total cellular RNA was extracted for Northern hybridization and radiolabeled with a glutaminase cDNA probe.. Of the cytokines studied, only IFN-gamma altered glutaminase activity. Kinetic studies indicated a decrease in activity secondary to a 25% decrease in Vmax with no change in Km, consistent with a reduction in the number of glutaminase molecules rather than a change in enzyme affinity. Glutaminase protein was decreased 50% in IFN-gamma-treated cells when compared with controls. This decrease was dose-independent and was associated with a concomitant 75% decrease in glutaminase messenger RNA levels. These reductions in message and protein translated into a 60-80% decrease in functional glutaminase-specific activity.. This IFN-gamma-mediated decrease in glutaminase activity may be one mechanism by which gut glutamine metabolism is diminished as the tumor grows and becomes the principal organ of glutamine use.

Topics: Adenocarcinoma; Cell Line, Transformed; Cells, Cultured; Colonic Neoplasms; Epithelium; Glutaminase; Humans; Interferon-gamma; Interleukin-1; Interleukin-6; Intestines; RNA, Messenger; Spectrophotometry; Tumor Necrosis Factor-alpha

Topics: Adenocarcinoma; Adenocarcinoma, Papillary; Animals; Carcinoma; Carcinoma, Squamous Cell; Glutaminase; Humans; Hydrogen-Ion Concentration; Isoenzymes; Kidney; Kinetics; Liver; Lung; Lung Neoplasms; Mitosis; Neoplasm Metastasis; Organometallic Compounds; Phosphates; Rats; Species Specificity

Topics: Adenocarcinoma; Adenoma; Animals; Carcinoma 256, Walker; Carcinoma, Squamous Cell; Fibrosarcoma; Glutaminase; Growth; Mammary Neoplasms, Experimental; Mathematics; Neoplasm Transplantation; Neoplasms; Neoplasms, Experimental; Osteosarcoma; Rats; Time Factors