glutaminase and compound-968

Glutamine metabolism is one of the hallmarks of cancers which is described as an essential role in serving as a major energy and building blocks supply to cell proliferation in cancer cells. Many malignant tumor cells always display glutamine addiction. The "kidney-type" glutaminase (GLS1) is a metabolism enzyme which plays a significant part in glutaminolysis. Interestingly, GLS1 is often overexpressed in highly proliferative cancer cells to fulfill enhanced glutamine demand. So far, GLS1 has been proved to be a significant target during the carcinogenesis process, and emerging evidence reveals that its inhibitors could provide a benefit strategy for cancer therapy. Herein, we summarize the prognostic value of GLS1 in multiple cancer type and its related regulatory factors which are associated with antitumor activity. Moreover, this review article highlights the remarkable reform of discovery and development for GLS1 inhibitors. On the basis of case studies, our perspectives for targeting GLS1 and development of GLS1 antagonist are discussed in the final part.

Topics: Apoptosis; Benzophenanthridines; Cell Proliferation; Diazooxonorleucine; Disease Progression; Drug Resistance, Neoplasm; Genes, myc; Glutaminase; Glutamine; Humans; MicroRNAs; Neoplasm Proteins; Neoplasms; NF-kappa B; Oxidation-Reduction; Phosphates; Prognosis; Retinoblastoma Protein; Sulfides; Thiadiazoles

Glutamine is one of the primary nutrients utilized by cancer cells for energy production and biosynthesis. Hence, interfering with glutamine metabolism may impose anti-tumor effects.. In this study, we assessed the anti-tumorigenic effects of glutaminase-1 enzyme (GLS1) inhibition in endometrial cancer in vitro and in vivo.. The human endometrial cancer cell lines Ishikawa and HEC-1B were used. The effects of compound 968 on cell proliferation, cell cycle, apoptosis, cellular stress, and AKT/mTOR pathway inhibition were assessed. The synergistic effects of compound 968 and paclitaxel were also analyzed. The in vivo effect of compound 968 was evaluated using tumor xenografts.. We found that the GLS1-targeting compound 968 was able to reduce cancer cell proliferation in a dose- and time-dependent manner. Compound 968 combined with a low concentration of paclitaxel showed stronger inhibitory effects. Further analyses indicated that compound 968 induced cell cycle arrest at the G1 phase, as well as increased the production of cellular reactive oxygen species (ROS) and promoted cellular stress and cancer cell apoptosis. Additionally, the treatment of endometrial cancer with compound 968 downregulated the expression of GLS1 and cyclin D1 and upregulated the expression of P21 and E-cadherin. Moreover, the treatment of endometrial cancer cells with compound 968 significantly reduced the levels of phospho-S6 ribosomal protein and phospho-AKT (Ser473), indicative of AKT/mTOR/S6 signaling pathway inhibition. In xenograft mouse models of endometrial cancer, compound 968 significantly suppressed tumor growth. In addition, western blotting analysis indicated that GLS1 expression was upregulated in human endometrial cancer tissues.. Compound 968 may be a promising approach for the management of human endometrial cancer.

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Endometrial Neoplasms; Female; Glutaminase; Glutamine; Humans; Mice; Paclitaxel; Proto-Oncogene Proteins c-akt; TOR Serine-Threonine Kinases

Programmed cell death 1 ligand (PD-L1) blockade has been used therapeutically in the treatment of ovarian cancer, and potential combination treatment approaches are under investigation to improve the treatment response rate. The increased dependence on glutamine is widely observed in various type of tumors, including ovarian cancer. Kidney-type glutaminase (GLS), as one of the isotypes of glutaminase, is found to promote tumorigenesis. Here, we have demonstrated that the combined treatment with GLS inhibitor 968 and PD-L1 blockade enhances the immune response against ovarian cancer. Survival analysis using the Kaplan-Meier plotter dataset from ovarian cancer patients revealed that the expression level of GLS predicts poor survival and correlates with the immunosuppressive microenvironment of ovarian cancer. 968 inhibits the proliferation of ovarian cancer cells and enhances granzyme B secretion by CD8

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Benzophenanthridines; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Synergism; Female; Gene Expression Regulation, Neoplastic; Glutaminase; Humans; Immune Checkpoint Inhibitors; Mice; Ovarian Neoplasms; Treatment Outcome; Tumor Microenvironment; Xenograft Model Antitumor Assays

Glutamine metabolism is an important metabolic pathway for cancer cell survival, and there is a critical connection between tumor growth and glutamine metabolism. However, the role of GLS1 in hepatocellular carcinoma (HCC) progression remains to be elucidated. In this study, we reported that GLS1 expression was significantly increased in HCC tissues and correlated with serum AFP, tumor differentiation, lymphatic metastasis, TNM stage, and poorer patient outcome. We further showed that GLS1 promoted colony formation and cell proliferation of HCC cells. Furthermore, our data showed that GLS1 inhibitor compound 968 inhibited the proliferation of HCC cells in a dose-dependent manner. Importantly, we found that GLS1 overexpression increased p-AKT, p-GSK3β and cyclinD1 expression, and had no influence on total AKT and GSK3β protein level, indicating that GLS1 was involved in AKT/GSK3β/CyclinD1 pathway. It is suggested that GLS1 promotes proliferation in HCC cells probably via AKT/GSK3β/CyclinD1 pathway and may be a potential target for anti-hepatocellular carcinoma cancer.

Topics: Animals; Benzophenanthridines; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Disease Progression; Drug Delivery Systems; Female; Glutaminase; Glycogen Synthase Kinase 3 beta; Humans; Liver Neoplasms; Male; Mice; Mice, Nude; Middle Aged; Oncogenes; Proto-Oncogene Proteins c-akt; Retrospective Studies; Signal Transduction; Up-Regulation

Suppressing glutaminolysis does not always induce cancer cell death in glutamine dependent tumors because cells may switch to alternative energy sources. To reveal compensatory metabolic pathways, we investigated the metabolome-wide cellular response to inhibited glutaminolysis in cancer cells. Glutaminolysis inhibition with C.968 suppressed cell proliferation but was insufficient to induce cancer cell death. We found that lipid catabolism was activated as a compensation for glutaminolysis inhibition. Accelerated lipid catabolism, together with oxidative stress induced by glutaminolysis inhibition, triggered autophagy. Simultaneously inhibiting glutaminolysis and either beta oxidation with trimetazidine or autophagy with chloroquine both induced cancer cell death. Here we identified metabolic escape mechanisms contributing to cancer cell survival under treatment and we suggest potentially translational strategy for combined cancer therapy, given that chloroquine is an FDA approved drug. Our findings are first to show efficiency of combined inhibition of glutaminolysis and beta oxidation as potential anti-cancer strategy as well as add to the evidence that combined inhibition of glutaminolysis and autophagy may be effective in glutamine-addicted cancers.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Benzophenanthridines; Cell Line, Tumor; Cell Proliferation; Chloroquine; Glutaminase; Glutamine; Humans; Lipolysis; Metabolomics; Neoplasms; Oxidative Stress

Adipose-derived stem cells (ASCs) are abundantly present in the mammary microenvironment and can promote breast cancer malignancy by differentiating into myofibroblasts. However, it remains largely unclear which role tumor-derived extracellular vesicles (TEVs) play in this process. Here, we used microfabricated, type I collagen-based 3-D tissue culture platforms to investigate the effect of breast cancer cell-derived TEVs on ASCs myofibroblast differentiation and consequential changes in extracellular matrix remodeling and vascular sprouting. TEVs collected from MDA MB-231 human metastatic breast cancer cells (MDAs) promoted ASC myofibroblast differentiation in both 2-D and 3-D cultures as indicated by increased alpha smooth muscle actin (α-SMA) and fibronectin (Fn) levels. Correspondingly, TEV-treated ASCs were more contractile, secreted more vascular endothelial growth factor (VEGF), and promoted angiogenic sprouting of human umbilical vein endothelial cells (HUVECs). These changes were dependent on transforming growth factor beta (TGF-β)-related signaling and tumor cell glutaminase activity as their inhibition decreased TEV-related myofibroblastic differentiation of ASCs and related functional consequences. In summary, our data suggest that TEVs are important signaling factors that contribute to ASC desmoplastic reprogramming in the tumor microenvironment, and suggest that tumor cell glutamine metabolism may be used as a therapeutic target to interfere with this process.

Topics: Actins; Adipocytes; Antibodies, Monoclonal; Benzophenanthridines; Biomarkers; Cell Culture Techniques; Cell Differentiation; Cell Line; Cell Line, Tumor; Cytokines; Epithelial Cells; Extracellular Matrix; Extracellular Vesicles; Female; Fibronectins; Gene Expression Regulation; Glutaminase; Human Umbilical Vein Endothelial Cells; Humans; Mitogen-Activated Protein Kinase 9; Myofibroblasts; Neovascularization, Pathologic; Signal Transduction; Stem Cells; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) erlotinib has been approved based on the clinical benefit in non-small cell lung cancer (NSCLC) patients over the past decade. Unfortunately, cancer cells become resistant to this agent via various mechanisms, and this limits the improvement in patient outcomes. Thus, it is urgent to develop novel agents to overcome erlotinib resistance. Here, we propose a novel strategy to overcome acquired erlotinib resistance in NSCLC by inhibiting glutaminase activity. Compound 968, an inhibitor of the glutaminase C (GAC), when combined with erlotinib potently inhibited the cell proliferation of erlotinib-resistant NSCLC cells HCC827ER and NCI-H1975. The combination of compound 968 and erlotinib not only decreased GAC and EGFR protein expression but also inhibited GAC activity in HCC827ER cells. The growth of erlotinib-resistant cells was glutamine-dependent as proved by GAC gene knocked down and rescue experiment. More importantly, compound 968 combined with erlotinib down-regulated the glutamine and glycolysis metabolism in erlotinib-resistant cells. Taken together, our study provides a valuable approach to overcome acquired erlotinib resistance by blocking glutamine metabolism and suggests that combination of EGFR-TKI and GAC inhibitor maybe a potential treatment strategy for acquired erlotinib-resistant NSCLC.

Topics: Apoptosis; Benzophenanthridines; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Erlotinib Hydrochloride; Flow Cytometry; Glutaminase; Humans; Lung Neoplasms; Mitochondria; Protein Kinase Inhibitors; RNA Interference; Time Factors

Reprogrammed metabolism and redox homeostasis are potential targets of cancer therapy. Our previous study demonstrated that the kidney form of glutaminase (GLS1) is highly expressed in hepatocellular carcinoma (HCC) cells and can be used as a target for effective anticancer therapy. Dihydroartemisinin (DHA) increases intracellular reactive oxygen species (ROS) levels leading to cytotoxicity in cancer cells. However, the heterogeneity of cancer cells often leads to differing responses to oxidative lesions. For instance, cancer cells with high ratio of GSH/GSSG, a critical ROS scavenger, are resistant to ROS-induced cytotoxicity. We postulate that a combinatorial strategy firstly disrupting redox homeostasis followed by DHA might yield a profound antitumor efficacy. In this study, when HCC cells were treated with a GLS1 inhibitor 968, the ROS elimination capacity was significantly reduced in HCC cells, which rendered HCC cells but not normal endothelial cells more sensitive to DHA-mediated cytotoxicity. We further confirmed that this synergistic antitumor efficacy was mediated by excessive ROS generation in HCC cells. NAC, a ROS inhibitor, partly rescued the combinatorial cytotoxic effect of 968 and DHA. Given that GLS1 is a potential antitumor target and DHA has been safely used in clinic, our findings provide new insight into liver cancer therapy targeting glutamine metabolism combined with the ROS generator DHA, which can be readily translated into cancer clinical trials.

Topics: Acetylcysteine; Antineoplastic Agents, Phytogenic; Apoptosis; Artemisinins; Benzophenanthridines; Cell Line; Cell Line, Tumor; Drug Combinations; Drug Synergism; Endothelial Cells; Enzyme Inhibitors; Gene Expression; Glutaminase; Glutathione; Glutathione Disulfide; Hepatocytes; Humans; Organ Specificity; Reactive Oxygen Species

The mechanistic target of rapamycin (mTOR) is hyperactivated in many types of cancer, rendering it a compelling drug target; however, the impact of mTOR inhibition on metabolic reprogramming in cancer is incompletely understood. Here, by integrating metabolic and functional studies in glioblastoma multiforme (GBM) cell lines, preclinical models, and clinical samples, we demonstrate that the compensatory upregulation of glutamine metabolism promotes resistance to mTOR kinase inhibitors. Metabolomic studies in GBM cells revealed that glutaminase (GLS) and glutamate levels are elevated following mTOR kinase inhibitor treatment. Moreover, these mTOR inhibitor-dependent metabolic alterations were confirmed in a GBM xenograft model. Expression of GLS following mTOR inhibitor treatment promoted GBM survival in an α-ketoglutarate-dependent (αKG-dependent) manner. Combined genetic and/or pharmacological inhibition of mTOR kinase and GLS resulted in massive synergistic tumor cell death and growth inhibition in tumor-bearing mice. These results highlight a critical role for compensatory glutamine metabolism in promoting mTOR inhibitor resistance and suggest that rational combination therapy has the potential to suppress resistance.

Topics: Aged; Animals; Antineoplastic Combined Chemotherapy Protocols; Benzophenanthridines; Brain Neoplasms; Cell Line, Tumor; Citric Acid Cycle; Drug Resistance, Neoplasm; Drug Synergism; Energy Metabolism; Gas Chromatography-Mass Spectrometry; Glioblastoma; Glutamic Acid; Glutaminase; Glutamine; Glycolysis; Humans; Indoles; Ketoglutaric Acids; Magnetic Resonance Spectroscopy; Male; Metabolome; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Targeted Therapy; Neoplasm Proteins; Protein Kinase Inhibitors; Purines; RNA, Small Interfering; Rotarod Performance Test; Signal Transduction; Temporal Lobe; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

The interplay of metabolism and epigenetic regulatory mechanisms has become a focal point for a better understanding of cancer development and progression. In this study, we have acquired data supporting previous observations that demonstrate glutamine metabolism affects histone modifications in human breast cancer cell lines. Treatment of non-invasive epithelial (T-47D and MDA-MB-361) and invasive mesenchymal (MDA-MB-231 and Hs-578T) breast cancer cell lines with the glutaminase inhibitor, Compound 968, resulted in cytotoxicity in all cell lines, with the greatest effect being observed in MDA-MB-231 breast cancer cells. Compound 968-treatment induced significant downregulation of 20 critical cancer-related genes, the majority of which are anti-apoptotic and/or promote metastasis, including AKT, BCL2, BCL2L1, CCND1, CDKN3, ERBB2, ETS1, E2F1, JUN, KITLG, MYB, and MYC. Histone H3K4me3, a mark of transcriptional activation, was reduced at the promoters of all but one of these critical cancer genes. The decrease in histone H3K4me3 at global and gene-specific levels correlated with reduced expression of SETD1 and ASH2L, genes encoding the histone H3K4 methyltransferase complex. Further, the expression of other epigenetic regulatory genes, known to be downregulated during apoptosis (e.g., DNMT1, DNMT3B, SETD1 and SIRT1), was also downregulated by Compound 968. These changes in gene expression and histone modifications were accompanied by the activation of apoptosis, and decreased invasiveness and resistance of MDA-MB-231 cells to chemotherapeutic drug doxorubicin. The results of this study provide evidence to a link between cytotoxicity caused by inhibiting glutamine metabolism with alterations of the epigenome of breast cancer cells and suggest that modification of intracellular metabolism may enhance the efficiency of epigenetic therapy.

Topics: Apoptosis; Benzophenanthridines; Breast Neoplasms; Cell Line, Tumor; Cell Survival; DNA (Cytosine-5-)-Methyltransferase 1; DNA (Cytosine-5-)-Methyltransferases; DNA Methyltransferase 3B; DNA-Binding Proteins; Enzyme Inhibitors; Epigenesis, Genetic; Female; Gene Expression Regulation, Neoplastic; Glutaminase; Glutamine; Histone-Lysine N-Methyltransferase; Histones; Humans; Nuclear Proteins; Promoter Regions, Genetic; Sirtuin 1; Transcription Factors