scholarly journals Lysine 53 Acetylation of Cytochrome c in Prostate Cancer: Warburg Metabolism and Evasion of Apoptosis

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 802
Author(s):  
Viktoriia Bazylianska ◽  
Hasini A. Kalpage ◽  
Junmei Wan ◽  
Asmita Vaishnav ◽  
Gargi Mahapatra ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cytochrome C ◽  
Warburg Effect ◽  
Structural Features ◽  
Intrinsic Apoptosis ◽  
Metabolic Switch ◽  
Cancer Hallmarks ◽  
Dynamics Simulations ◽  
The Warburg Effect

Prostate cancer is the second leading cause of cancer-related death in men. Two classic cancer hallmarks are a metabolic switch from oxidative phosphorylation (OxPhos) to glycolysis, known as the Warburg effect, and resistance to cell death. Cytochrome c (Cytc) is at the intersection of both pathways, as it is essential for electron transport in mitochondrial respiration and a trigger of intrinsic apoptosis when released from the mitochondria. However, its functional role in cancer has never been studied. Our data show that Cytc is acetylated on lysine 53 in both androgen hormone-resistant and -sensitive human prostate cancer xenografts. To characterize the functional effects of K53 modification in vitro, K53 was mutated to acetylmimetic glutamine (K53Q), and to arginine (K53R) and isoleucine (K53I) as controls. Cytochrome c oxidase (COX) activity analyzed with purified Cytc variants showed reduced oxygen consumption with acetylmimetic Cytc compared to the non-acetylated Cytc (WT), supporting the Warburg effect. In contrast to WT, K53Q Cytc had significantly lower caspase-3 activity, suggesting that modification of Cytc K53 helps cancer cells evade apoptosis. Cardiolipin peroxidase activity, which is another proapoptotic function of the protein, was lower in acetylmimetic Cytc. Acetylmimetic Cytc also had a higher capacity to scavenge reactive oxygen species (ROS), another pro-survival feature. We discuss our experimental results in light of structural features of K53Q Cytc, which we crystallized at a resolution of 1.31 Å, together with molecular dynamics simulations. In conclusion, we propose that K53 acetylation of Cytc affects two hallmarks of cancer by regulating respiration and apoptosis in prostate cancer xenografts.

The warburg effect and tumour cell survival in human GBMs

2007 ◽  
Vol 30 (4) ◽  
pp. 97 ◽  
Author(s):  
A Wolf ◽  
J Mukherjee ◽  
A Guha
Keyword(s):  
Cytochrome C ◽  
Cell Survival ◽  
Expression Profile ◽  
Tumour Cell ◽  
Warburg Effect ◽  
Glycolytic Enzymes ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
The Warburg Effect

Introduction: GBMs are resistant to apoptosis induced by the hypoxic microenvironment and standard therapies including radiation and chemotherapy. We postulate that the Warburg effect, a preferential glycolytic phenotype of tumor cells even under aerobic conditions, plays a role in these aberrant pro-survival signals. In this study we quantitatively examined the expression profile of hypoxia-related glycolytic genes within pathologically- and MRI-defined “centre” and “periphery” of GBMs. We hypothesize that expression of hypoxia-induced glycolytic genes, particularly hexokinase 2 (HK2), favours cell survival and modulates resistance to tumour cell apoptosis by inhibiting the intrinsic mitochondrial apoptotic pathway. Methods: GBM patients underwent conventional T1-weighted contrast-enhanced MRI and MR spectroscopy studies on a 3.0T GE scanner, prior to stereotactic sampling (formalin and frozen) from regions which were T1-Gad enhancing (“centre”) and T2-positive, T1-Gad negative (“periphery”). Real-time qRT-PCR was performed to quantify regional gene expression of glycolytic genes including HK2. In vitro functional studies were performed in U87 and U373 GBM cell lines grown in normoxic (21% pO2) and hypoxic (< 1%pO2) conditions, transfected with HK2 siRNA followed by measurement of cell proliferation (BrdU), apoptosis (activated caspase 3/7, TUNEL, cytochrome c release) and viability (MTS assay). Results: There exists a differential expression profile of glycolytic enzymes between the hypoxic center and relatively normoxic periphery of GBMs. Under hypoxic conditions, there is increased expression of HK2 at the mitochondrial membrane in GBM cells. In vitro HK2 knockdown led to decreased cell survival and increased apoptosis via the intrinsic mitochondrial pathway, as seen by increased mitochondrial release of cytochrome-C. Conclusions: Increased expression of HK2 in the centre of GBMs promotes cell survival and confers resistance to apoptosis, as confirmed by in vitro studies. In vivo intracranial xenograft studies with injection of HK2-shRNA are currently being performed. HK2 and possibly other glycolytic enzymes may provide a target for enhanced therapeutic responsiveness thereby improving prognosis of patients with GBMs.

In vitro and in vivo investigations of novel 1,4-napthoquinone sulphomethylene carbohydrate conjugates in prostate cancer.

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 104-104
Author(s):  
Tobias Busenbender ◽  
Sergey Dyshlovoy ◽  
Moritz Kaune ◽  
Lukas Boeckelmann ◽  
Tobias Lange ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Er Stress ◽  
Cancer Cells ◽  
Warburg Effect ◽  
Human Prostate ◽  
Human Prostate Cancer ◽  
Apoptotic Pathway ◽  
The Warburg Effect

104 Background: The Warburg effect describes the ability of cancer cells to consume larger amounts of glucose in comparison to normal tissue, due to the overexpression of insulin-independent glucose transporters (e.g. GLUT1). This effect can be used to enhance the selectivity and reduce side effects of cytotoxic anticancer molecules by its conjugation to sugar residues, thus, generating cytotoxic agents showing higher selectivity to cancer cells. In continuation of our research on anticancer natural 1,4-naphthoquinones we have investigated a large series of novel semi-synthetic molecules containing 1,4-naphthoquinones element conjugated with glucose molecule via -S-CH2- bond. Methods: We performed screening examinations for 35 novel synthetic molecules in human prostate cancer in vitro. The selected most active compounds were tested in several human prostate cancer cell lines harboring different levels of drug resistance, as well as in non-malignant cells to specify their selectivity. Compounds with the highest cytotoxicity and selectivity were further investigated. The mode of action was assessed including effects on apoptosis induction, oxidative stress, mitochondria, AR-signaling as well as glucose uptake and ER stress were assessed. In vivo dose finding and efficacy analyses were performed. Results: We identified two promising derivatives, showing IC50s at low micro- and nanomolar concentrations. Glucose depletion from the culture media led to increased cytotoxicity and cotreatment with a GLUT1-inhibitor showed an antagonistic effect, suggesting a concurrent uptake and therefore a Warburg effect targeting. The selected compounds exhibited most pronounced cytotoxic activity in DU145 cells as well as 22Rv1 cells. Non-malignant cells were generally less affected. The mode of action involves a loss of mitochondrial membrane potential, a release of cytochrome c and AIF into the cytosol and an upregulation of caspase-9, caspase-3 and cleaved PARP, as well as downregulation of Bcl-2 and Survivin, indicating that mitochondria are a major target, leading to the activation of the intrinsic apoptotic pathway. Early events in treated cells are ROS production and calcium release into the cytosol, a marker of ER-stress. Furthermore, downregulation of the AR and its signaling was observed on mRNA- and protein-level. In vivo experiments revealed antitumor activity in a 22Rv1-xenograft mouse model without severe side effects. Conclusions: In conclusion, we were able to identify two glucose-conjugated 1,4-naphthoquinones exhibiting potent in vitro and in vivoactivity and selectivity in human prostate cancer cells due to the Warburg effect targeting. Cytotoxic activity was exerted via initial ROS production and ER stress leading to mitochondrial damage and the induction of the intrinsic apoptotic pathway.

scholarly journals miR-206 regulates a metabolic switch in nasopharyngeal carcinoma by suppressing HK2 expression

2020 ◽  
Author(s):  
Chunying Luo ◽  
Min Liu ◽  
Jianwei Zhang ◽  
Guoqiang Su ◽  
Zhonghua Wei
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Warburg Effect ◽  
Carcinoma Cells ◽  
Luciferase Reporter ◽  
Metabolic Shift ◽  
Invasion And Metastasis ◽  
Metabolic Switch ◽  
And Function ◽  
The Relationship

Abstract Background: Many studies have shown that microRNAs play key functions in nasopharyngeal carcinoma proliferation, invasion and metastasis. However, whether the dysregulated level of miRNAs contributes to the metabolic shift in nasopharyngeal carcinoma is not completely understood.Objectives: This study was conducted to explore the expression and function of miR-206 in nasopharyngeal carcinoma.Methods: miR-206 expression level was examined by real-time PCR. miR-206 inhibitor, mimics, and scrambled control were transiently transfected into nasopharyngeal carcinoma cells and their effects on colony formation, glucose uptake, and lactate secretion were observed in vitro. Moreover, the relationship between the levels of miR-206 and HK2 was examined by luciferase reporter and assay western blot.Results: In our study, we reported downregulation of miR-206 expression leads to metabolic change in nasopharyngeal carcinoma cells. miR-206 controls this function by enhancing HK2 expression. The enhancement of aerobic metabolism activity induced by miR-206 leads to the rapid proliferation of nasopharyngeal carcinoma cells.Conclusions: Our data demonstrated that miR-206 was involved in the regulation of Warburg effect in nasopharyngeal carcinoma by suppressing HK2 expression.

scholarly journals Proton export drives the Warburg Effect

2021 ◽  
Author(s):  
Shonagh Russell ◽  
Liping Xu ◽  
Yoonseok Kam ◽  
Dominique Abrahams ◽  
Bryce Ordway ◽  
...  
Keyword(s):  
Warburg Effect ◽  
Cancer Metabolism ◽  
Aerobic Glycolysis ◽  
Lactate Production ◽  
Glycolytic Enzymes ◽  
Hek293 Cells ◽  
Driver Mutations ◽  
The Warburg Effect

Aggressive cancers commonly ferment glucose to lactic acid at high rates, even in the presence of oxygen. This is known as aerobic glycolysis, or the “Warburg Effect”. It is widely assumed that this is a consequence of the upregulation of glycolytic enzymes. Oncogenic drivers can increase the expression of most proteins in the glycolytic pathway, including the terminal step of exporting H+ equivalents from the cytoplasm. Proton exporters maintain an alkaline cytoplasmic pH, which can enhance all glycolytic enzyme activities, even in the absence of oncogene-related expression changes. Based on this observation, we hypothesized that increased uptake and fermentative metabolism of glucose could be driven by the expulsion of H+ equivalents from the cell. To test this hypothesis, we stably transfected lowly-glycolytic MCF-7, U2-OS, and glycolytic HEK293 cells to express proton exporting systems: either PMA1 (yeast H+-ATPase) or CAIX (carbonic anhydrase 9). The expression of either exporter in vitro enhanced aerobic glycolysis as measured by glucose consumption, lactate production, and extracellular acidification rate. This resulted in an increased intracellular pH, and metabolomic analyses indicated that this was associated with an increased flux of all glycolytic enzymes upstream of pyruvate kinase. These cells also demonstrated increased migratory and invasive phenotypes in vitro, and these were recapitulated in vivo by more aggressive behavior, whereby the acid-producing cells formed higher grade tumors with higher rates of metastases. Neutralizing tumor acidity with oral buffers reduced the metastatic burden. Therefore, cancer cells with increased H+ export increase intracellular alkalization, even without oncogenic driver mutations, and this is sufficient to alter cancer metabolism towards a Warburg phenotype.

scholarly journals The roles of sphingosine kinases 1 and 2 in regulating the Warburg effect in prostate cancer cells

2013 ◽  
Vol 25 (4) ◽  
pp. 1011-1017 ◽  
Author(s):  
David G. Watson ◽  
Francesca Tonelli ◽  
Manal Alossaimi ◽  
Leon Williamson ◽  
Edmond Chan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Warburg Effect ◽  
Prostate Cancer Cells ◽  
Sphingosine Kinases ◽  
The Warburg Effect

scholarly journals Lactic Acidosis in Prostate Cancer: Consider the Warburg Effect

2017 ◽  
Vol 10 (3) ◽  
pp. 1085-1091 ◽  
Author(s):  
Johannes C. van der Mijn ◽  
Mathijs J. Kuiper ◽  
Carl E.H. Siegert ◽  
Annabeth E. Wassenaar ◽  
Carel J.M. van Noesel ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Lactic Acidosis ◽  
Warburg Effect ◽  
Blood Gas Analysis ◽  
Tp53 Gene ◽  
Gas Analysis ◽  
Metabolic Reprogramming ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
The Warburg Effect

Lactic acidosis is a commonly observed clinical condition that is associated with a poor prognosis, especially in malignancies. We describe a case of an 81-year-old patient who presented with symptoms of tachypnea and general discomfort. Arterial blood gas analysis showed a high anion gap acidosis with a lactate level of 9.5 mmol/L with respiratory compensation. CT scanning showed no signs of pulmonary embolism or other causes of impaired tissue oxygenation. Despite treatment with sodium bicarbonate, the patient developed an adrenalin-resistant cardiac arrest, most likely caused by the acidosis. Autopsy revealed Gleason score 5 + 5 metastatic prostate cancer as the most probable cause of the lactic acidosis. Next-generation sequencing indicated a nonsense mutation in the TP53 gene (887delA) and an activating mutation in the PIK3CA gene (1634A>G) as candidate molecular drivers. This case demonstrates the prevalence and clinical relevance of metabolic reprogramming, frequently referred to as “the Warburg effect,” in patients with prostate cancer.

scholarly journals Senescence-inducing stress promotes proteolysis of phosphoglycerate mutase via ubiquitin ligase Mdm2

2014 ◽  
Vol 204 (5) ◽  
pp. 729-745 ◽  
Author(s):  
Takumi Mikawa ◽  
Takeshi Maruyama ◽  
Koji Okamoto ◽  
Hitoshi Nakagama ◽  
Matilde E. Lleonart ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Warburg Effect ◽  
Cultured Cells ◽  
Glycolytic Enzyme ◽  
Phosphoglycerate Mutase ◽  
Proliferative Potential ◽  
Downstream Effector ◽  
Direct Binding ◽  
The Warburg Effect

Despite the well-documented clinical significance of the Warburg effect, it remains unclear how the aggressive glycolytic rates of tumor cells might contribute to other hallmarks of cancer, such as bypass of senescence. Here, we report that, during oncogene- or DNA damage–induced senescence, Pak1-mediated phosphorylation of phosphoglycerate mutase (PGAM) predisposes the glycolytic enzyme to ubiquitin-mediated degradation. We identify Mdm2 as a direct binding partner and ubiquitin ligase for PGAM in cultured cells and in vitro. Mutations in PGAM and Mdm2 that abrogate ubiquitination of PGAM restored the proliferative potential of primary cells under stress conditions and promoted neoplastic transformation. We propose that Mdm2, a downstream effector of p53, attenuates the Warburg effect via ubiquitination and degradation of PGAM.

scholarly journals III. Cellular ultrastructures in situ as key to understanding tumor energy metabolism: biological significance of the Warburg effect

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 10 ◽  
Author(s):  
Halina Witkiewicz ◽  
Phil Oh ◽  
Jan E Schnitzer
Keyword(s):  
Warburg Effect ◽  
Cancer Metabolism ◽  
Biological Significance ◽  
Tissue Growth ◽  
High Rate ◽  
Intermediate Form ◽  
Malignant Cells ◽  
Metabolic Switch ◽  
The Warburg Effect

Despite the universality of metabolic pathways, malignant cells were found to have their metabolism reprogrammed to generate energy by glycolysis even under normal oxygen concentrations (the Warburg effect). Therefore, the pathway energetically 18 times less efficient than oxidative phosphorylation was implicated to match increased energy requirements of growing tumors. The paradox was explained by an abnormally high rate of glucose uptake, assuming unlimited availability of substrates for tumor growth in vivo. However, ultrastructural analysis of tumor vasculature morphogenesis showed that the growing tissue regions did not have continuous blood supply and intermittently depended on autophagy for survival. Erythrogenic autophagy, and resulting ATP generation by glycolysis, appeared critical to initiating vasculature formation where it was missing. This study focused on ultrastructural features that reflected metabolic switch from aerobic to anaerobic. Morphological differences between and within different types of cells were evident in tissue sections. In cells undergoing nucleo-cytoplasmic conversion into erythrosomes (erythrogenesis), gradual changes led to replacing mitochondria with peroxisomes, through an intermediate form connected to endoplasmic reticulum. Those findings related to the issue of peroxisome biogenesis and to the phenomenon of hemogenic endothelium. Mitochondria were compacted also during mitosis. In vivo, cells that lost and others that retained capability to use oxygen coexisted side-by-side; both types were important for vasculature morphogenesis and tissue growth. Once passable, the new vasculature segment could deliver external oxygen and nutrients. Nutritional and redox status of microenvironment had similar effect on metabolism of malignant and non-malignant cells demonstrating the necessity to maintain structure-energy equivalence in all living cells. The role of glycolysis in initiating vasculature formation, and in progression of cell cycle through mitosis, indicated that Warburg effect had a fundamental biological significance extending to non-malignant tissues. The approach used here could facilitate integration of accumulated cyber knowledge on cancer metabolism into predictive science.

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