Dichloroacetate Radiosensitizes Hypoxic Breast Cancer Cells

Mitochondrial metabolism is an attractive target for cancer therapy. Reprogramming metabolic pathways can potentially sensitize tumors with limited treatment options, such as triple-negative breast cancer (TNBC), to chemo- and/or radiotherapy. Dichloroacetate (DCA) is a specific inhibitor of the pyruvate dehydrogenase kinase (PDK), which leads to enhanced reactive oxygen species (ROS) production. ROS are the primary effector molecules of radiation and an increase hereof will enhance the radioresponse. In this study, we evaluated the effects of DCA and radiotherapy on two TNBC cell lines, namely EMT6 and 4T1, under aerobic and hypoxic conditions. As expected, DCA treatment decreased phosphorylated pyruvate dehydrogenase (PDH) and lowered both extracellular acidification rate (ECAR) and lactate production. Remarkably, DCA treatment led to a significant increase in ROS production (up to 15-fold) in hypoxic cancer cells but not in aerobic cells. Consistently, DCA radiosensitized hypoxic tumor cells and 3D spheroids while leaving the intrinsic radiosensitivity of the tumor cells unchanged. Our results suggest that although described as an oxidative phosphorylation (OXPHOS)-promoting drug, DCA can also increase hypoxic radioresponses. This study therefore paves the way for the targeting of mitochondrial metabolism of hypoxic cancer cells, in particular to combat radioresistance.

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Hemistepsin A suppresses colorectal cancer growth through inhibiting pyruvate dehydrogenase kinase activity

Scientific Reports ◽

10.1038/s41598-020-79019-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Ling Jin ◽

Eun-Yeong Kim ◽

Tae-Wook Chung ◽

Chang Woo Han ◽

So Young Park ◽

...

Keyword(s):

Colorectal Cancer ◽

Cancer Cells ◽

Pyruvate Dehydrogenase ◽

Cancer Metabolism ◽

Aerobic Glycolysis ◽

Lactate Production ◽

Pyruvate Dehydrogenase Kinase ◽

Cancer Drug ◽

Potential Candidate ◽

Mitochondrial Ros

AbstractMost cancer cells primarily produce their energy through a high rate of glycolysis followed by lactic acid fermentation even in the presence of abundant oxygen. Pyruvate dehydrogenase kinase (PDK) 1, an enzyme responsible for aerobic glycolysis via phosphorylating and inactivating pyruvate dehydrogenase (PDH) complex, is commonly overexpressed in tumors and recognized as a therapeutic target in colorectal cancer. Hemistepsin A (HsA) is a sesquiterpene lactone isolated from Hemistepta lyrata Bunge (Compositae). Here, we report that HsA is a PDK1 inhibitor can reduce the growth of colorectal cancer and consequent activation of mitochondrial ROS-dependent apoptotic pathway both in vivo and in vitro. Computational simulation and biochemical assays showed that HsA directly binds to the lipoamide-binding site of PDK1, and subsequently inhibits the interaction of PDK1 with the E2 subunit of PDH complex. As a result of PDK1 inhibition, lactate production was decreased, but oxygen consumption was increased. Mitochondrial ROS levels and mitochondrial damage were also increased. Consistent with these observations, the apoptosis of colorectal cancer cells was promoted by HsA with enhanced activation of caspase-3 and -9. These results suggested that HsA might be a potential candidate for developing a novel anti-cancer drug through suppressing cancer metabolism.

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A Novel Therapeutic Target, BACH1, Regulates Cancer Metabolism

Cells ◽

10.3390/cells10030634 ◽

2021 ◽

Vol 10 (3) ◽

pp. 634

Author(s):

Joselyn Padilla ◽

Jiyoung Lee

Keyword(s):

Cancer Cells ◽

Cancer Patients ◽

Transcriptional Activation ◽

Pyruvate Dehydrogenase ◽

Therapeutic Target ◽

Cancer Metabolism ◽

Aerobic Glycolysis ◽

Mitochondrial Metabolism ◽

Pyruvate Dehydrogenase Kinase ◽

Migration And Invasion

BTB domain and CNC homology 1 (BACH1) is a transcription factor that is highly expressed in tumors including breast and lung, relative to their non-tumor tissues. BACH1 is known to regulate multiple physiological processes including heme homeostasis, oxidative stress response, senescence, cell cycle, and mitosis. In a tumor, BACH1 promotes invasion and metastasis of cancer cells, and the expression of BACH1 presents a poor outcome for cancer patients including breast and lung cancer patients. Recent studies identified novel functional roles of BACH1 in the regulation of metabolic pathways in cancer cells. BACH1 inhibits mitochondrial metabolism through transcriptional suppression of mitochondrial membrane genes. In addition, BACH1 suppresses activity of pyruvate dehydrogenase (PDH), a key enzyme that converts pyruvate to acetyl-CoA for the citric acid (TCA) cycle through transcriptional activation of pyruvate dehydrogenase kinase (PDK). Moreover, BACH1 increases glucose uptake and lactate secretion through the expression of metabolic enzymes involved such as hexokinase 2 (HK2) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) for aerobic glycolysis. Pharmacological or genetic inhibition of BACH1 could reprogram by increasing mitochondrial metabolism, subsequently rendering metabolic vulnerability of cancer cells against mitochondrial respiratory inhibition. Furthermore, inhibition of BACH1 decreased antioxidant-induced glycolysis rates as well as reduced migration and invasion of cancer cells, suggesting BACH1 as a potentially useful cancer therapeutic target.

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Inhibition of mitochondrial pyruvate dehydrogenase kinase: a proposed mechanism by which melatonin causes cancer cells to overcome cytosolic glycolysis, reduce tumor biomass and reverse insensitivity to chemotherapy

Melatonin Research ◽

10.32794/mr11250033 ◽

2019 ◽

Vol 2 (3) ◽

pp. 105-119 ◽

Cited By ~ 19

Author(s):

Russel J Reiter ◽

Ramaswamy Sharma ◽

Qiang Ma ◽

Sergio Rosales-Corral ◽

Dario Acuna-Castroviejo ◽

...

Keyword(s):

Breast Cancer ◽

Oxidative Phosphorylation ◽

Cancer Cells ◽

Pyruvate Dehydrogenase ◽

Warburg Effect ◽

Breast Cancer Cells ◽

Pyruvate Dehydrogenase Kinase ◽

Cell Phenotype ◽

Acetyl Coa ◽

The Warburg Effect

This review presents a hypothesis to explain the role of melatonin in regulating glucose metabolism in cancer cells. Many cancer cells use cytosolic glycolysis (the Warburg effect) to produce energy (ATP). Under these conditions, glucose is primarily converted to lactate which is released into the blood in large quantities. The Warburg effect gives cancer cells advantages in terms of enhanced macromolecule synthesis required for accelerated cellular proliferation, reduced cellular apoptosis which enhances tumor biomass and a greater likelihood of metastasis. Based on available data, high circulating melatonin levels at night serve as a signal for breast cancer cells to switch from cytosolic glycolysis to mitochondrial glucose oxidation and oxidative phosphorylation for ATP production. In this situation, melatonin promotes the synthesis of acetyl-CoA from pyruvate; we speculate that melatonin does this by inhibiting the mitochondrial enzyme pyruvate dehydrogenase kinase (PDK) which normally inhibits pyruvate dehydrogenase complex (PDC), the enzyme that controls the pyruvate to acetyl-CoA conversion. Acetyl-CoA has several important functions in the mitochondria; it feeds into the citric acid cycle which improves oxidative phosphorylation and, additionally, it is a necessary co-factor for the rate limiting enzyme, arylalkylamine N-acetyltransferase, in mitochondrial melatonin synthesis. When breast cancer cells are using cytosolic glycolysis (during the day) they are of the cancer phenotype; at night when they are using mitochondria to produce ATP via oxidative phosphorylation, they have a normal cell phenotype. If this day:night difference in tumor cell metabolism is common in other cancers, it indicates that these tumor cells are only cancerous part of the time. We also speculate that high nighttime melatonin levels also reverse the insensitivity of tumors to chemotherapy.

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CAIX-Mediated Control of LIN28/let-7 Axis Contributes to Metabolic Adaptation of Breast Cancer Cells to Hypoxia

International Journal of Molecular Sciences ◽

10.3390/ijms21124299 ◽

2020 ◽

Vol 21 (12) ◽

pp. 4299 ◽

Cited By ~ 3

Author(s):

Adriana Gibadulinova ◽

Petra Bullova ◽

Hynek Strnad ◽

Kamil Pohlodek ◽

Dana Jurkovicova ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Pyruvate Dehydrogenase ◽

Biological Effects ◽

Pyruvate Dehydrogenase Kinase ◽

Metabolic Adaptation ◽

Breast Cancer Cell Lines ◽

Adaptation To Hypoxia ◽

Stem Cell Markers ◽

Breast Cancer Patients

Solid tumors, including breast cancer, are characterized by the hypoxic microenvironment, extracellular acidosis, and chemoresistance. Hypoxia marker, carbonic anhydrase IX (CAIX), is a pH regulator providing a selective survival advantage to cancer cells through intracellular neutralization while facilitating tumor invasion by extracellular acidification. The expression of CAIX in breast cancer patients is associated with poor prognosis and metastases. Importantly, CAIX-positive hypoxic tumor regions are enriched in cancer stem cells (CSCs). Here we investigated the biological effects of CA9-silencing in breast cancer cell lines. We found that CAIX-downregulation in hypoxia led to increased levels of let-7 (lethal-7) family members. Simultaneously with the increase of let-7 miRNAs in CAIX-suppressed cells, LIN28 protein levels decreased, along with downstream metabolic pathways: pyruvate dehydrogenase kinase 1 (PDK1) and phosphorylation of its substrate, pyruvate dehydrogenase (PDH) at Ser-232, causing attenuation of glycolysis. In addition to perturbed glycolysis, CAIX-knockouts, in correlation with decreased LIN28 (as CSC reprogramming factor), also exhibit reduction of the further CSC-associated markers NANOG (Homeobox protein NANOG) and ALDH1 (Aldehyde dehydrogenase isoform 1). Oppositely, overexpression of CAIX leads to the enhancement of LIN28, ALDH1, and NANOG. In conclusion, CAIX-driven regulation of the LIN28/let-7 axis augments glycolytic metabolism and enhances stem cell markers expression during CAIX-mediated adaptation to hypoxia and acidosis in carcinogenesis.

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Recent Advances on Therapeutic Peptides for Breast Cancer Treatment

Current Protein and Peptide Science ◽

10.2174/1389203721999201117123616 ◽

2020 ◽

Vol 21 ◽

Author(s):

Samad Beheshtirouy ◽

Farhad Mirzaei ◽

Shirin Eyvazi ◽

Vahideh Tarhriz

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Tumor Cells ◽

Breast Cancer Cells ◽

Specific Binding ◽

High Specificity ◽

The Novel ◽

Anti Cancer ◽

Therapeutic Peptides ◽

Low Toxicity

: Breast cancer is a heterogeneous malignancy which is the second cause of mortality among women in the world. Increasing the resistance to anti-cancer drugs in breast cancer cells persuades researchers to search the novel therapies approaches for the treatment of the malignancy. Among the novel methods, therapeutic peptides which target and disrupt tumor cells have been of great interest. Therapeutic peptides are short amino acids monomer chains with high specificity to bind and modulate a protein interaction of interest. Several advantages of peptides such as specific binding on tumor cells surface, low molecular weight and low toxicity on normal cells make the peptides as an appealing therapeutic agents against solid tumors, particularly breast cancer. Also, National Institutes of Health (NIH) describes therapeutic peptides as suitable candidate for the treatment of drug-resistant breast cancer. In this review, we attempt to review the different therapeutic peptides against breast cancer cells which can be used in treatment and diagnosis of the malignancy. Meanwhile, we presented an overview of peptide vaccines which have been developed for the treatment of breast cancer.

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Matrix Stiffness Modulates Metabolic Interaction between Human Stromal and Breast Cancer Cells to Stimulate Epithelial Motility

Metabolites ◽

10.3390/metabo11070432 ◽

2021 ◽

Vol 11 (7) ◽

pp. 432

Author(s):

Iván Ponce ◽

Nelson Garrido ◽

Nicolás Tobar ◽

Francisco Melo ◽

Patricio C. Smith ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Cancer Progression ◽

Stromal Cells ◽

Glucose Transporter ◽

Lactate Production ◽

Resonance Energy ◽

Metabolic Reprogramming ◽

Dependent Manner ◽

Functional Link

Breast tumors belong to the type of desmoplastic lesion in which a stiffer tissue structure is a determinant of breast cancer progression and constitutes a risk factor for breast cancer development. It has been proposed that cancer-associated stromal cells (responsible for this fibrotic phenomenon) are able to metabolize glucose via lactate production, which supports the catabolic metabolism of cancer cells. The aim of this work was to investigate the possible functional link between these two processes. To measure the effect of matrix rigidity on metabolic determinations, we used compliant elastic polyacrylamide gels as a substrate material, to which matrix molecules were covalently linked. We evaluated metabolite transport in stromal cells using two different FRET (Fluorescence Resonance Energy Transfer) nanosensors specific for glucose and lactate. Cell migration/invasion was evaluated using Transwell devices. We show that increased stiffness stimulates lactate production and glucose uptake by mammary fibroblasts. This response was correlated with the expression of stromal glucose transporter Glut1 and monocarboxylate transporters MCT4. Moreover, mammary stromal cells cultured on stiff matrices generated soluble factors that stimulated epithelial breast migration in a stiffness-dependent manner. Using a normal breast stromal cell line, we found that a stiffer extracellular matrix favors the acquisition mechanistical properties that promote metabolic reprograming and also constitute a stimulus for epithelial motility. This new knowledge will help us to better understand the complex relationship between fibrosis, metabolic reprogramming, and cancer malignancy.

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Genetic Perturbation of Pyruvate Dehydrogenase Kinase 1 Modulates Growth, Angiogenesis and Metabolic Pathways in Ovarian Cancer Xenografts

Cells ◽

10.3390/cells10020325 ◽

2021 ◽

Vol 10 (2) ◽

pp. 325

Author(s):

Carolina Venturoli ◽

Ilaria Piga ◽

Matteo Curtarello ◽

Martina Verza ◽

Giovanni Esposito ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Pyruvate Dehydrogenase ◽

Metabolic Pathways ◽

Negative Impact ◽

Digital Pathology ◽

Pyruvate Dehydrogenase Kinase ◽

Ovarian Cancer Cells ◽

Pyruvate Dehydrogenase Kinase 1

Pyruvate dehydrogenase kinase 1 (PDK1) blockade triggers are well characterized in vitro metabolic alterations in cancer cells, including reduced glycolysis and increased glucose oxidation. Here, by gene expression profiling and digital pathology-mediated quantification of in situ markers in tumors, we investigated effects of PDK1 silencing on growth, angiogenesis and metabolic features of tumor xenografts formed by highly glycolytic OC316 and OVCAR3 ovarian cancer cells. Notably, at variance with the moderate antiproliferative effects observed in vitro, we found a dramatic negative impact of PDK1 silencing on tumor growth. These findings were associated with reduced angiogenesis and increased necrosis in the OC316 and OVCAR3 tumor models, respectively. Analysis of viable tumor areas uncovered increased proliferation as well as increased apoptosis in PDK1-silenced OVCAR3 tumors. Moreover, RNA profiling disclosed increased glucose catabolic pathways—comprising both oxidative phosphorylation and glycolysis—in PDK1-silenced OVCAR3 tumors, in line with the high mitotic activity detected in the viable rim of these tumors. Altogether, our findings add new evidence in support of a link between tumor metabolism and angiogenesis and remark on the importance of investigating net effects of modulations of metabolic pathways in the context of the tumor microenvironment.

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The Mechanical Fingerprint of Circulating Tumor Cells (CTCs) in Breast Cancer Patients

Cancers ◽

10.3390/cancers13051119 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1119

Author(s):

Ivonne Nel ◽

Erik W. Morawetz ◽

Dimitrij Tschodu ◽

Josef A. Käs ◽

Bahriye Aktas

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Cancer Patients ◽

Tumor Cells ◽

Circulating Tumor Cells ◽

Hematopoietic Cells ◽

Surrogate Marker ◽

Clinical Samples ◽

Breast Cancer Patients ◽

Shape Restoration

Circulating tumor cells (CTCs) are a potential predictive surrogate marker for disease monitoring. Due to the sparse knowledge about their phenotype and its changes during cancer progression and treatment response, CTC isolation remains challenging. Here we focused on the mechanical characterization of circulating non-hematopoietic cells from breast cancer patients to evaluate its utility for CTC detection. For proof of premise, we used healthy peripheral blood mononuclear cells (PBMCs), human MDA-MB 231 breast cancer cells and human HL-60 leukemia cells to create a CTC model system. For translational experiments CD45 negative cells—possible CTCs—were isolated from blood samples of patients with mamma carcinoma. Cells were mechanically characterized in the optical stretcher (OS). Active and passive cell mechanical data were related with physiological descriptors by a random forest (RF) classifier to identify cell type specific properties. Cancer cells were well distinguishable from PBMC in cell line tests. Analysis of clinical samples revealed that in PBMC the elliptic deformation was significantly increased compared to non-hematopoietic cells. Interestingly, non-hematopoietic cells showed significantly higher shape restoration. Based on Kelvin–Voigt modeling, the RF algorithm revealed that elliptic deformation and shape restoration were crucial parameters and that the OS discriminated non-hematopoietic cells from PBMC with an accuracy of 0.69, a sensitivity of 0.74, and specificity of 0.63. The CD45 negative cell population in the blood of breast cancer patients is mechanically distinguishable from healthy PBMC. Together with cell morphology, the mechanical fingerprint might be an appropriate tool for marker-free CTC detection.

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Arginine Methyltransferase PRMT1 Regulates p53 Activity in Breast Cancer

Life ◽

10.3390/life11080789 ◽

2021 ◽

Vol 11 (8) ◽

pp. 789

Author(s):

Li-Ming Liu ◽

Qiang Tang ◽

Xin Hu ◽

Jing-Jing Zhao ◽

Yuan Zhang ◽

...

Keyword(s):

Breast Cancer ◽

Cell Growth ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Asymmetric Dimethylarginine ◽

Human Cancer ◽

Specific Inhibitor ◽

Dependent Manner ◽

Breast Tumorigenesis ◽

Stress Signals

The protein p53 is one of the most important tumor suppressors, responding to a variety of stress signals. Mutations in p53 occur in about half of human cancer cases, and dysregulation of the p53 function by epigenetic modifiers and modifications is prevalent in a large proportion of the remainder. PRMT1 is the main enzyme responsible for the generation of asymmetric-dimethylarginine, whose upregulation or aberrant splicing has been observed in many types of malignancies. Here, we demonstrate that p53 function is regulated by PRMT1 in breast cancer cells. PRMT1 knockdown activated the p53 signal pathway and induced cell growth-arrest and senescence. PRMT1 could directly bind to p53 and inhibit the transcriptional activity of p53 in an enzymatically dependent manner, resulting in a decrease in the expression levels of several key downstream targets of the p53 pathway. We were able to detect p53 asymmetric-dimethylarginine signals in breast cancer cells and breast cancer tissues from patients, and the signals could be significantly weakened by silencing of PRMT1 with shRNA, or inhibiting PRMT1 activity with a specific inhibitor. Furthermore, PRMT1 inhibitors significantly impeded cell growth and promoted cellular senescence in breast cancer cells and primary tumor cells. These results indicate an important role of PRMT1 in the regulation of p53 function in breast tumorigenesis.

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Emerging roles of cancer-testis antigenes, semenogelin 1 and 2, in neoplastic cells

Cell Death Discovery ◽

10.1038/s41420-021-00482-4 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Oleg Shuvalov ◽

Alyona Kizenko ◽

Alexey Petukhov ◽

Olga Fedorova ◽

Alexandra Daks ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Tumor Cells ◽

Reproductive System ◽

Seminal Fluid ◽

Cancer Development ◽

Migration And Invasion ◽

Malignant Cells ◽

Cancer Testis

AbstractCancer-testicular Antigens (CTAs) belong to a group of proteins that under normal conditions are strictly expressed in a male’s reproductive tissues. However, upon malignisation, they are frequently re-expressed in neoplastic tissues of various origin. A number of studies have shown that different CTAs affect growth, migration and invasion of tumor cells and favor cancer development and metastasis. Two members of the CTA group, Semenogelin 1 and 2 (SEMG1 and SEMG2, or SEMGs) represent the major component of human seminal fluid. They regulate the motility and capacitation of sperm. They are often re-expressed in different malignancies including breast cancer. However, there is almost no information about the functional properties of SEMGs in cancer cells. In this review, we highlight the role of SEMGs in the reproductive system and also summarize the data on their expression and functions in malignant cells of various origins.

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