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Frontiers in Cell and Developmental... 2021Mutations of H-Ras, a member of the RAS family, are preferentially found in cutaneous squamous cell carcinomas (SCCs). H-Ras has been reported to induce autophagy, which...
Mutations of H-Ras, a member of the RAS family, are preferentially found in cutaneous squamous cell carcinomas (SCCs). H-Ras has been reported to induce autophagy, which plays an essential role in tissue homeostasis in multiple types of cancer cells and in fibroblasts, however, the potential role of H-Ras in regulating autophagy in human keratinocytes has not been reported. In this study, we found that the stable expression of the G12V mutant of H-RAS (H-Ras ) induced autophagy in human keratinocytes, and interestingly, the induction of autophagy was strongly blocked by inhibiting the calcineurin/nuclear factor of activated T cells (NFAT) pathway with either a calcineurin inhibitor (Cyclosporin A) or a NFAT inhibitor (VIVIT), or by the small interfering RNA (siRNA) mediated knockdown of calcineurin B1 or NFATc1 , as well as To characterize the role of the calcineurin/NFAT pathway in H-Ras induced autophagy, we found that H-Ras promoted the nuclear translocation of NFATc1, an indication of the activation of the calcineurin/NFAT pathway, in human keratinocytes. However, activation of NFATc1 either by the forced expression of NFATc1 or by treatment with phenformin, an AMPK activator, did not increase the formation of autophagy in human keratinocytes. Further study revealed that inhibiting the calcineurin/NFAT pathway actually suppressed H-Ras expression in H-Ras overexpressing cells. Finally, chromatin immunoprecipitation (ChIP) assays showed that NFATc1 potentially binds the promoter region of H-Ras and the binding efficiency was significantly enhanced by the overexpression of H-Ras , which was abolished by treatment with the calcineurin/NFAT pathway inhibitors cyclosporine A (CsA) or VIVIT. Taking these data together, the present study demonstrates that the calcineurin/NFAT signaling pathway controls H-Ras expression and interacts with the H-Ras pathway, involving the regulation of H-Ras induced autophagy in human keratinocytes.
PubMed: 34350189
DOI: 10.3389/fcell.2021.720111 -
ELife Jun 2021Chemotherapy resistance is a critical barrier in cancer treatment. Metabolic adaptations have been shown to fuel therapy resistance; however, little is known regarding...
Chemotherapy resistance is a critical barrier in cancer treatment. Metabolic adaptations have been shown to fuel therapy resistance; however, little is known regarding the generality of these changes and whether specific therapies elicit unique metabolic alterations. Using a combination of metabolomics, transcriptomics, and functional genomics, we show that two anthracyclines, doxorubicin and epirubicin, elicit distinct primary metabolic vulnerabilities in human breast cancer cells. Doxorubicin-resistant cells rely on glutamine to drive oxidative phosphorylation and glutathione synthesis, while epirubicin-resistant cells display markedly increased bioenergetic capacity and mitochondrial ATP production. The dependence on these distinct metabolic adaptations is revealed by the increased sensitivity of doxorubicin-resistant cells and tumor xenografts to buthionine sulfoximine (BSO), a drug that interferes with glutathione synthesis, compared with epirubicin-resistant counterparts that are more sensitive to the biguanide phenformin. Overall, our work reveals that metabolic adaptations can vary with therapeutics and that these metabolic dependencies can be exploited as a targeted approach to treat chemotherapy-resistant breast cancer.
Topics: Animals; Antibiotics, Antineoplastic; Breast Neoplasms; Cell Line, Tumor; Doxorubicin; Drug Resistance, Neoplasm; Epirubicin; Female; Mice; Mice, Inbred NOD; Mice, SCID
PubMed: 34181531
DOI: 10.7554/eLife.65150 -
Proceedings of the National Academy of... Jun 2021Epstein-Barr virus (EBV) is a ubiquitous herpesvirus that typically causes asymptomatic infection but can promote B lymphoid tumors in the immune suppressed. In vitro,...
Epstein-Barr virus (EBV) is a ubiquitous herpesvirus that typically causes asymptomatic infection but can promote B lymphoid tumors in the immune suppressed. In vitro, EBV infection of primary B cells stimulates glycolysis during immortalization into lymphoblastoid cell lines (LCLs). Lactate export during glycolysis is crucial for continued proliferation of many cancer cells-part of a phenomenon known as the "Warburg effect"- and is mediated by monocarboxylate transporters (MCTs). However, the role of MCTs has yet to be studied in EBV-associated malignancies, which display Warburg-like metabolism in vitro. Here, we show that EBV infection of B lymphocytes directly promotes temporal induction of MCT1 and MCT4 through the viral proteins EBNA2 and LMP1, respectively. Functionally, MCT1 was required for early B cell proliferation, and MCT4 up-regulation promoted acquired resistance to MCT1 antagonism in LCLs. However, dual MCT1/4 inhibition led to LCL growth arrest and lactate buildup. Metabolic profiling in LCLs revealed significantly reduced oxygen consumption rates (OCRs) and NAD+/NADH ratios, contrary to previous observations of increased OCR and unaltered NAD+/NADH ratios in MCT1/4-inhibited cancer cells. Furthermore, U-C-glucose labeling of MCT1/4-inhibited LCLs revealed depleted glutathione pools that correlated with elevated reactive oxygen species. Finally, we found that dual MCT1/4 inhibition also sensitized LCLs to killing by the electron transport chain complex I inhibitors phenformin and metformin. These findings were extended to viral lymphomas associated with EBV and the related gammaherpesvirus KSHV, pointing at a therapeutic approach for targeting both viral lymphomas.
Topics: B-Lymphocytes; Cell Line, Tumor; Cell Proliferation; Epstein-Barr Virus Infections; Glucose; Glutathione; Herpesvirus 4, Human; Herpesvirus 8, Human; Humans; Lactic Acid; Lymphoma; Metformin; Monocarboxylic Acid Transporters; NAD; Oxygen Consumption; Phenformin; Reactive Oxygen Species; Up-Regulation
PubMed: 34161263
DOI: 10.1073/pnas.2022495118 -
Nature Communications Jun 2021Bioenergetic perturbations driving neoplastic growth increase the production of reactive oxygen species (ROS), requiring a compensatory increase in ROS scavengers to...
Bioenergetic perturbations driving neoplastic growth increase the production of reactive oxygen species (ROS), requiring a compensatory increase in ROS scavengers to limit oxidative stress. Intervention strategies that simultaneously induce energetic and oxidative stress therefore have therapeutic potential. Phenformin is a mitochondrial complex I inhibitor that induces bioenergetic stress. We now demonstrate that inflammatory mediators, including IFNγ and polyIC, potentiate the cytotoxicity of phenformin by inducing a parallel increase in oxidative stress through STAT1-dependent mechanisms. Indeed, STAT1 signaling downregulates NQO1, a key ROS scavenger, in many breast cancer models. Moreover, genetic ablation or pharmacological inhibition of NQO1 using β-lapachone (an NQO1 bioactivatable drug) increases oxidative stress to selectively sensitize breast cancer models, including patient derived xenografts of HER2+ and triple negative disease, to the tumoricidal effects of phenformin. We provide evidence that therapies targeting ROS scavengers increase the anti-neoplastic efficacy of mitochondrial complex I inhibitors in breast cancer.
Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Cell Line, Tumor; Drug Synergism; Electron Transport Complex I; Energy Metabolism; Female; Glutathione; Humans; Interferon-gamma; MCF-7 Cells; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Mice, Knockout; Mice, SCID; NAD(P)H Dehydrogenase (Quinone); Naphthoquinones; Oxidative Stress; Phenformin; Poly I-C; Reactive Oxygen Species; STAT1 Transcription Factor; Xenograft Model Antitumor Assays
PubMed: 34083537
DOI: 10.1038/s41467-021-23396-2 -
Cancers May 2021In the Cancers paper, we observed the increase ALDH1L1 protein expression following oncogenesis, as well as a therapeutic effect, by deleting the gene in mice, a model...
Reply to Krupenko et al. Comment on "Lee et al. The Combination of Loss of ALDH1L1 Function and Phenformin Treatment Decreases Tumor Growth in KRAS-Driven Lung Cancer 2020, , 1382".
In the Cancers paper, we observed the increase ALDH1L1 protein expression following oncogenesis, as well as a therapeutic effect, by deleting the gene in mice, a model of spontaneous non-small cell lung cancer (NSCLC) [...].
PubMed: 34066916
DOI: 10.3390/cancers13092238 -
Cancers Apr 2021We read with interest the article by Lee et al [...].
Is ALDH1L1 Elevated in Lung Cancer? Comment on: Lee, S.-H.; et al. "The Combination of Loss of ALDH1L1 Function and Phenformin Treatment Decreases Tumor Growth in KRAS-Driven Lung Cancer" 2020, , 1382.
We read with interest the article by Lee et al [...].
PubMed: 33918472
DOI: 10.3390/cancers13071691 -
Trends in Cancer Aug 2021Biguanides are a class of antidiabetic drugs that includes phenformin and metformin; however, the former was withdrawn from approval in many countries due to its... (Review)
Review
Biguanides are a class of antidiabetic drugs that includes phenformin and metformin; however, the former was withdrawn from approval in many countries due to its toxicity. Findings from retrospective epidemiological studies in diabetic populations and preclinical laboratory models have demonstrated that biguanides possess antitumor activities that suggest their repurposing for cancer prevention and treatment. However, a better understanding of how these biguanides behave as antitumor agents is needed to guide their improved applications in cancer therapy, spurring increased interest in their pharmacology. Here, we present evidence for proposed mechanisms of action related to their antitumor activity, including their effects on central carbon metabolism in cancer cells and immune-modulating activity, and then review progress on biguanide repurposing in cancer therapeutics and the possible re-evaluation of phenformin as a cancer therapeutic agent.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Biguanides; Cell Line, Tumor; Clinical Trials as Topic; Disease Models, Animal; Drug Repositioning; Drug Synergism; Humans; Immune Checkpoint Inhibitors; Neoplasms; Oxidative Phosphorylation; Protein Kinase Inhibitors; Tumor Microenvironment; Xenograft Model Antitumor Assays
PubMed: 33865798
DOI: 10.1016/j.trecan.2021.03.001 -
Hereditas Apr 2021Type 2 Diabetes Mellitus (T2DM) is an independent risk factor of hepatocellular carcinoma (HCC). However, the related genes and modules to hepatocarcinogenesis and...
BACKGROUND
Type 2 Diabetes Mellitus (T2DM) is an independent risk factor of hepatocellular carcinoma (HCC). However, the related genes and modules to hepatocarcinogenesis and progression in T2DM remain unclear.
METHODS
The microarray data from Gene Expression Omnibus (GEO) were analyzed to screen differentially expressed genes (DEGs) of T2DM and HCC dataset. Then, weighted gene co-expression network analysis (WGCNA) was performed on these DEGs to detect the modules and genes, respectively. Common genes in modules with clinical interests of T2DM and HCC were obtained and annotated via GOSemSim package and Metascape. Genes related to late-stage HCC and high glycated haemoglobin (HbA1c) were also identified. These genes were validated by UALCAN analysis and univariate cox regression based on The Cancer Genome Atlas (TCGA). Finally, another two independent datasets were applied to confirm the results of our study.
RESULTS
A total of 1288 and 1559 DEGs of T2DM and HCC were screened, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment revealed several shared pathways in two diseases, such as pathways in cancer and metabolism. A total of 37 common genes correlated with T2DM and HCC were then identified with WGCNA. Furthermore, 12 genes from modules associated with late-stage HCC and high HbA1c were regarded as hub genes. Among these genes, 8 genes associated with tumor invasion and metastasis were validated by UALCAN analysis. Moreover, downregulations of ACAT1, SLC2A2, PCK1 and ABAT were significantly associated with poorer prognosis in HCC patients with elevated HbA1c. Additionally, the expressions of PCK1 and ABAT were raised in HepG2 cells pre-treated with metformin and phenformin.
CONCLUSIONS
The present study confirmed several metabolic genes related to hyperglycemia and malignant tumor, which may provide not only new insights into the pathogenesis of hepatocarcinogenesis and progression in T2DM, but also novel therapeutic targets for T2DM patients with HCC in the future.
Topics: Biomarkers, Tumor; Carcinoma, Hepatocellular; Diabetes Mellitus, Type 2; Gene Ontology; Glycated Hemoglobin; Hep G2 Cells; Humans; Liver Neoplasms; Oligonucleotide Array Sequence Analysis; Risk Factors
PubMed: 33865459
DOI: 10.1186/s41065-021-00177-x -
The FEBS Journal Oct 2021Many metabolic phenotypes in cancer cells are also characteristic of proliferating nontransformed mammalian cells, and attempts to distinguish between phenotypes...
Many metabolic phenotypes in cancer cells are also characteristic of proliferating nontransformed mammalian cells, and attempts to distinguish between phenotypes resulting from oncogenic perturbation from those associated with increased proliferation are limited. Here, we examined the extent to which metabolic changes corresponding to oncogenic KRAS expression differed from those corresponding to epidermal growth factor (EGF)-driven proliferation in human mammary epithelial cells (HMECs). Removal of EGF from culture medium reduced growth rates and glucose/glutamine consumption in control HMECs despite limited changes in respiration and fatty acid synthesis, while the relative contribution of branched-chain amino acids to the TCA cycle and lipogenesis increased in the near-quiescent conditions. Most metabolic phenotypes measured in HMECs expressing mutant KRAS were similar to those observed in EGF-stimulated control HMECs that were growing at comparable rates. However, glucose and glutamine consumption as well as lactate and glutamate production were lower in KRAS-expressing cells cultured in media without added EGF, and these changes correlated with reduced sensitivity to GLUT1 inhibitor and phenformin treatment. Our results demonstrate the strong dependence of metabolic behavior on growth rate and provide a model to distinguish the metabolic influences of oncogenic mutations and nononcogenic growth.
Topics: Animals; Breast; Breast Neoplasms; Carcinogenesis; Cell Proliferation; Epidermal Growth Factor; Epithelial Cells; Female; Gene Expression Regulation, Neoplastic; Glucose; Glucose Transporter Type 1; Glutamic Acid; Glutamine; Humans; Lactic Acid; Mammary Glands, Human; Proto-Oncogene Proteins p21(ras); Tumor Cells, Cultured
PubMed: 33811729
DOI: 10.1111/febs.15858 -
Proceedings of the National Academy of... Mar 2021-amplified neuroblastoma is a lethal subset of pediatric cancer. MYCN drives numerous effects in the cell, including metabolic changes that are critical for oncogenesis....
-amplified neuroblastoma is a lethal subset of pediatric cancer. MYCN drives numerous effects in the cell, including metabolic changes that are critical for oncogenesis. The understanding that both compensatory pathways and intrinsic redundancy in cell systems exists implies that the use of combination therapies for effective and durable responses is necessary. Additionally, the most effective targeted therapies exploit an "Achilles' heel" and are tailored to the genetics of the cancer under study. We performed an unbiased screen on select metabolic targeted therapy combinations and correlated sensitivity with over 20 subsets of cancer. We found that -amplified neuroblastoma is hypersensitive to the combination of an inhibitor of the lactate transporter MCT1, AZD3965, and complex I of the mitochondrion, phenformin. Our data demonstrate that MCT4 is highly correlated with resistance to the combination in the screen and lowly expressed in -amplified neuroblastoma. Low MCT4 combines with high expression of the MCT2 and MCT1 chaperone CD147 in -amplified neuroblastoma, altogether conferring sensitivity to the AZD3965 and phenformin combination. The result is simultaneous disruption of glycolysis and oxidative phosphorylation, resulting in dramatic disruption of adenosine triphosphate (ATP) production, endoplasmic reticulum stress, and cell death. In mouse models of -amplified neuroblastoma, the combination was tolerable at concentrations where it shrank tumors and did not increase white-blood-cell toxicity compared to single drugs. Therefore, we demonstrate that a metabolic combination screen can identify vulnerabilities in subsets of cancer and put forth a metabolic combination therapy tailored for -amplified neuroblastoma that demonstrates efficacy and tolerability in vivo.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Basigin; Cell Line, Tumor; Cell Proliferation; Electron Transport Complex I; Gene Amplification; Humans; Mice; Mitochondria; Monocarboxylic Acid Transporters; N-Myc Proto-Oncogene Protein; Neuroblastoma; Phenformin; Pyrimidinones; Symporters; Thiophenes; Xenograft Model Antitumor Assays
PubMed: 33762304
DOI: 10.1073/pnas.2009620118