11 results on '"Vazquez-Martin, Alejandro"'
Search Results
2. Polo-like kinase 1 directs the AMPK-mediated activation of myosin regulatory light chain at the cytokinetic cleavage furrow independently of energy balance.
- Author
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Vazquez-Martin A, Cufí S, Oliveras-Ferraros C, and Menendez JA
- Subjects
- AMP-Activated Protein Kinases analysis, Cell Line, Tumor, Cytokinesis, Energy Metabolism, Humans, Mitosis, Myosin Light Chains analysis, Phosphorylation, Protein Binding, Spindle Apparatus metabolism, Polo-Like Kinase 1, AMP-Activated Protein Kinases metabolism, Cell Cycle Proteins metabolism, Myosin Light Chains metabolism, Protein Serine-Threonine Kinases metabolism, Proto-Oncogene Proteins metabolism
- Abstract
It has been recently proposed that AMP-activated protein kinase (AMPK) might indirectly promote the phosphorylation of MRLC (myosin II regulatory light chain) at Ser19 to regulate the transition from metaphase to anaphase and the completion of cytokinesis. Although these findings provide biochemical support for our earlier observations showing that the active form of the α catalytic AMPK subunit associates dynamically with essential mitotic regulators, several important issues remained unexplored. Does glucose starvation alter the ability of AMPK to bind to the mitotic apparatus and travel from centrosomes to the spindle midzone during mitosis and cytokinesis? Does AMPK activate MRLC exclusively at the cleavage furrow during cytokinesis? What is the mitosis-specific stimulus that activates the mito-cytokinetic AMPK/MRLC axis regardless of energy deprivation? First, we confirm that exogenous glucose deprivation fails to alter the previously described distribution of phospho-AMPKα(Thr172) in all of the mitotic phases and does not disrupt its apparent association with the mitotic spindle and other structures involved in cell division. Second, we establish for the first time that phospho-AMPKα(Thr172) colocalizes exclusively with Ser19-phosphorylated MRLC at the cleavage furrow of dividing cells, a previously unvisualized interaction between phospho-AMPKα(Thr172) and phospho-MRLC(Ser19) that occurs in cleavage furrows, intercellular bridges and the midbody during cell division that appears to occur irrespective of glucose availability. Third, we reveal for the first time that the inhibition of AMPK mitotic activity in response to PLK1 inhibition completely prevents the co-localization of phospho-AMPKα(Thr172) and phospho-MRLC(Ser19) during the final stages of cytokinesis and midbody ring formation. Because PLK1 inhibition efficiently suppresses the AMPK-mediated activation of MRLC at the cytokinetic cleavage furrow, we propose a previously unrecognized role for AMPK in ensuring that cytokinesis occurs at the proper place and time by establishing a molecular dialog between PLK1 and MRLC in an energy-independent manner.
- Published
- 2012
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3. Metabolomic fingerprint reveals that metformin impairs one-carbon metabolism in a manner similar to the antifolate class of chemotherapy drugs.
- Author
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Corominas-Faja B, Quirantes-Piné R, Oliveras-Ferraros C, Vazquez-Martin A, Cufí S, Martin-Castillo B, Micol V, Joven J, Segura-Carretero A, and Menendez JA
- Subjects
- AMP-Activated Protein Kinase Kinases, Ataxia Telangiectasia Mutated Proteins, Breast Neoplasms drug therapy, Breast Neoplasms metabolism, Carbon metabolism, Female, Glutathione metabolism, Humans, Hypoglycemic Agents therapeutic use, MCF-7 Cells, Metabolome, Metformin therapeutic use, Nucleotides metabolism, Purines, Thymidine, AMP-Activated Protein Kinases metabolism, Cell Cycle Proteins metabolism, DNA-Binding Proteins metabolism, Folic Acid Antagonists pharmacology, Hypoglycemic Agents pharmacology, Metformin pharmacology, Protein Serine-Threonine Kinases metabolism, Tumor Suppressor Proteins metabolism
- Abstract
Metabolomic fingerprint of breast cancer cells treated with the antidiabetic drug metformin revealed a significant accumulation of 5-formimino-tetrahydrofolate, one of the tetrahydrofolate forms carrying activated one-carbon units that are essential for the de novo synthesis of purines and pyrimidines. De novo synthesis of glutathione, a folate-dependent pathway interconnected with one-carbon metabolism was concomitantly depleted in response to metformin. End-product reversal studies demonstrated that thymidine alone leads to a significant but incomplete protection from metformin's cytostatic effects. The addition of the substrate hypoxanthine for the purine salvage pathway produces major rightward shifts in metformin's growth inhibition curves. Metformin treatment failed to activate the DNA repair protein ATM kinase and the metabolic tumor suppressor AMPK when thymidine and hypoxanthine were present in the extracellular milieu. Our current findings suggest for the first time that metformin can function as an antifolate chemotherapeutic agent that induces the ATM/AMPK tumor suppressor axis secondarily following the alteration of the carbon flow through the folate-related one-carbon metabolic pathways.
- Published
- 2012
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- View/download PDF
4. AMPK: a bona fide resident of the mitotic spindle midzone.
- Author
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Menendez JA and Vazquez-Martin A
- Subjects
- AMP-Activated Protein Kinases chemistry, Aurora Kinases, Chromosomal Proteins, Non-Histone metabolism, Humans, Mitosis, Phosphorylation, Protein Serine-Threonine Kinases metabolism, Spindle Apparatus metabolism, AMP-Activated Protein Kinases metabolism, Spindle Apparatus enzymology
- Published
- 2012
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5. Activation of AMP-activated protein kinase (AMPK) provides a metabolic barrier to reprogramming somatic cells into stem cells.
- Author
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Vazquez-Martin A, Vellon L, Quirós PM, Cufí S, Ruiz de Galarreta E, Oliveras-Ferraros C, Martin AG, Martin-Castillo B, López-Otín C, and Menendez JA
- Subjects
- Animals, Biphenyl Compounds, Cellular Reprogramming, Fibroblasts cytology, Fibroblasts drug effects, Humans, Hypoglycemic Agents pharmacology, Induced Pluripotent Stem Cells metabolism, Kruppel-Like Factor 4, Kruppel-Like Transcription Factors genetics, Kruppel-Like Transcription Factors metabolism, Metformin pharmacology, Mice, Mice, Inbred C57BL, Octamer Transcription Factor-3 genetics, Octamer Transcription Factor-3 metabolism, Proto-Oncogene Proteins c-myc genetics, Proto-Oncogene Proteins c-myc metabolism, Pyrones pharmacology, SOXB1 Transcription Factors genetics, SOXB1 Transcription Factors metabolism, Thiophenes pharmacology, Tumor Suppressor Protein p53 deficiency, Tumor Suppressor Protein p53 genetics, Tumor Suppressor Protein p53 metabolism, AMP-Activated Protein Kinases metabolism, Induced Pluripotent Stem Cells cytology
- Abstract
The ability of somatic cells to reprogram their ATP-generating machinery into a Warburg-like glycolytic metabotype while overexpressing stemness genes facilitates their conversion into either induced pluripotent stem cells (iPSCs) or tumor-propagating cells. AMP-activated protein kinase (AMPK) is a metabolic master switch that senses and decodes intracellular changes in energy status; thus, we have evaluated the impact of AMPK activation in regulating the generation of iPSCs from nonstem cells of somatic origin. The indirect and direct activation of AMPK with the antidiabetic biguanide metformin and the thienopyridone A-769662, respectively, impeded the reprogramming of mouse embryonic and human diploid fibroblasts into iPSCs. The AMPK activators established a metabolic barrier to reprogramming that could not be bypassed, even through p53 deficiency, a fundamental mechanism to greatly improve the efficiency of stem-cell production. Treatment with metformin or A-769662 before the generation of iPSC colonies was sufficient to drastically decrease iPSC generation, suggesting that AMPK activation impedes early stem cell genetic reprogramming. Monitoring the transcriptional activation status of each individual reprogramming factor (i.e., Oct4, Sox2, Klf4 and c-Myc) revealed that AMPK activation notably prevented the transcriptional activation of Oct4, the master regulator of the pluripotent state. AMPK activation appears to impose a normalized metabolic flow away from the required pro-immortalizing glycolysis that fuels the induction of stemness and pluripotency, endowing somatic cells with an energetic infrastructure that is protected against reprogramming. AMPK-activating anti-reprogramming strategies may provide a roadmap for the generation of novel cancer therapies that metabolically target tumor-propagating cells.
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- 2012
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6. Polo-like kinase 1 regulates activation of AMP-activated protein kinase (AMPK) at the mitotic apparatus.
- Author
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Vazquez-Martin A, Oliveras-Ferraros C, Cufí S, and Menendez JA
- Subjects
- AMP-Activated Protein Kinases metabolism, Benzimidazoles pharmacology, Centrosome metabolism, Chromosome Segregation, Cytokinesis drug effects, Energy Metabolism, Female, Fluorescent Antibody Technique, HeLa Cells, Humans, Kinetochores metabolism, Microscopy, Confocal, Mitosis, Phosphorylation drug effects, Protein Kinase Inhibitors pharmacology, Thiophenes pharmacology, Polo-Like Kinase 1, AMP-Activated Protein Kinases antagonists & inhibitors, Cell Cycle Proteins antagonists & inhibitors, Cell Cycle Proteins metabolism, Protein Serine-Threonine Kinases antagonists & inhibitors, Protein Serine-Threonine Kinases metabolism, Proto-Oncogene Proteins antagonists & inhibitors, Proto-Oncogene Proteins metabolism, Signal Transduction, Spindle Apparatus metabolism
- Abstract
AMP-activated protein kinase (AMPK) is being primarily studied as a central metabolic stress sensor, which regulates cell survival and growth-related metabolic pathways to preserve intracellular ATP levels in response to energy deprivation. Evidence is now accumulating that AMPK plays also an obligatory role to ensure proper cell division and faithful chromosomal segregation during mitosis. Increased phosphorylation in the AMPK catalytic subunit (AMPKα) was found in a proteomic study for kinases activated during G2/M and, more recently, activated AMPKα (PP-AMPKα(Thr172)) has been observed to transiently associate with several mitotic structures including centrosomes, spindle poles, the central spindle midzone and the midbody throughout all of the mitotic stages and cytokinesis. How AMPKα activation is controlled spatially and temporally during mitosis, however, remained undiscovered. Because Polo-like Kinases (PLKs) regulate many aspects of mitotic progression including centrosome maturation, bipolar spindle assembly, chromosome congression & segregation, and cytokinesis, we decided to combine an immunofluorescence microscopy analysis with a chemical biology approach employing a small-molecule PLK1 inhibitor to dissect a putative relationship between PLK1 and AMPKα during G2/M transition. PLK1 and PP-AMPKα(Thr172) were found to display a major spatio-temporal overlap early at centrosomes, from prophase until anaphase, and late at the midbody, during telophase and cytokinesis. Moreover, short-term treatment with the thiophene derivative GW843682X, a selective PLK inhibitor that has 400-fold greater potency for PLK1 than for PLK2 or PLK3, fully abolished mitotic activation of AMPKα. Upon long-term PLK1 inhibition, PP-AMPKα(Thr172) was barely detected surrounding the spindle poles of prometaphase-like arrested cells displaying the "polo" phenotype. Similarly, PP-AMPKα(Thr172) was largely inhibited in GW843682X-treated cells exhibiting cytokinesis failure and binucleate cell formation. Given that PLK1 is a well-recognized master regulatory kinase for the numerous protein substrates involved in mitosis, our current description of a causal link between PLK1 activity and mitotic phosphorylation of AMPKα may provide fundamental insights into how the energy sensor AMPK is directly coupled to mitotic cell division and cell cycle exist.
- Published
- 2011
- Full Text
- View/download PDF
7. AMPK: Evidence for an energy-sensing cytokinetic tumor suppressor.
- Author
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Vazquez-Martin A, Oliveras-Ferraros C, Lopez-Bonet E, and Menendez JA
- Subjects
- AMP-Activated Protein Kinases metabolism, Animals, Cell Line, Tumor, Cell Nucleus drug effects, Cell Proliferation drug effects, Humans, Metformin pharmacology, Mitosis drug effects, Tumor Suppressor Proteins metabolism, AMP-Activated Protein Kinases physiology, Energy Metabolism physiology, Evolution, Molecular, Mitosis physiology, Neoplasms physiopathology, Tumor Suppressor Proteins physiology
- Abstract
The AMP-activated protein kinase (AMPK) system, an evolutionary conserved low-energy checkpoint, functions as a canonical suppressor of cell proliferation. Proliferating cells, however, should also ensure a proper spatio-temporal bond between AMPK-sensed cell's metabolic status and cell division. A crucial linkage between cell proliferation and AMPK-interpreted cell bioenergetics appears to take place during the M-phase of the cell cycle. A recent description of a physical interplay between the active form the alpha-catalytic AMPK subunit with essential mitotic regulators in the centrosome and midbody has provided direct evidence that tumor-suppressive properties for AMPK closely relate to its ability to exquisitely coordinate sensing of energy resources and the fundamental biological process of genome division during mitosis and cytokinesis. Based on recent findings in our laboratory observing abortive cytokinesis followed by nuclear shape reorganization, mitotic catastrophe, polyploidization events, and cell giantism in p53-null cancer cells pharmacologically manipulated to exhibit sustained activation of AMPK, we now propose that AMPK is a novel and biologically significant participant with a tumor suppressive activity in the mitotic/cytokinetic phase of the cell cycle. In this scenario, molecular co-evolution of the energy-sensing cytokinetic tumor suppressor AMPK within the chronic biophysical constraints of the tumor microenvironment may inherently promote a continuous generation of structural and numerical changes in chromosomes favoring generation of nascent tumor cells and/or tumor-initiating cells over tumor cell death.
- Published
- 2009
- Full Text
- View/download PDF
8. The active form of the metabolic sensor: AMP-activated protein kinase (AMPK) directly binds the mitotic apparatus and travels from centrosomes to the spindle midzone during mitosis and cytokinesis.
- Author
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Vazquez-Martin A, Oliveras-Ferraros C, and Menendez JA
- Subjects
- Anaphase physiology, Animals, Aurora Kinase A, Aurora Kinase B, Aurora Kinases, Cell Line, Tumor, Chromosome Segregation, Humans, Mice, Protein Serine-Threonine Kinases metabolism, Spindle Apparatus ultrastructure, Telophase physiology, Tubulin metabolism, AMP-Activated Protein Kinases metabolism, Centrosome enzymology, Cytokinesis, Mitosis, Spindle Apparatus enzymology
- Abstract
The metabolic rheostat AMP-activated protein kinase (AMPK) is unexpectedly required for proper cell division and faithful chromosomal segregation during mitosis. Although it is conceptually attractive to assume that AMPK-interpreted microenvironmental bioenergetics may strictly engage cell's energy status, cell grow, and cell division to avoid that energy stresses trigger cell death, the ultimate framework of AMPK activity towards chromosomal and cytoskeletal mitotic regulation is a question that remains unanswered. We herein reveal that the active form of the alpha-catalytic AMPK subunit (P-AMPKalpha(Thr172))-but not its total form (AMPKalpha)-transiently associates with several mitotic structures including centrosomes, spindle poles, the central spindle midzone and the midbody throughout all of the mitotic stages and cytokinesis in human cancer-derived epithelial cells. At prophase, P-AMPKalpha(Thr172) associates with the two asters of microtubules that begin to nucleate from mature centrosomes. The overlapping localization of P-AMPKalpha(Thr172) with the mitotic centrosomal Aurora-A kinase is also apparent on the microtubules near the spindle poles in metaphase and in early anaphase. This Aurora A-like centrosomal localization of P-AMPKalpha(Thr172) cannot be detected following chromatid separation following anaphase-telophase transition. Rather, toward the end of anaphase and in telophase P-AMPKalpha(Thr172) reactivity exhibited a similar but not identical localization to that occupied by the bona fide chromosomal passenger proteins INCENCP and Aurora-B. This localization of P-AMPKalpha(Thr172) at the central spindle and midbody persisted during the furrowing process and, at the completion of telophase, staining of P-AMPKalpha(Thr172) as doublet was apparent on either side of the midbody within the intercellular cytokinetic bridge. An identical mitotic geography of P-AMPKalpha(Thr172) was observed in cancer cells lacking the AMPK kinase LKB1, in non-cancerous human epithelial cells, and in mouse fibroblasts. The active form of AMPKalpha bound to the mitotic apparatus may physically tether the bioenergetic state of a cell to the four-dimensional regulation of the chromosomal and cytoskeletal mitotic events, thus suggesting a putative cytokinetic suppressor function. In this newly discovered scenario, we suggest a primordial mitotic role for the alpha catalytic AMPK subunit in the eukaryotic evolutionary process as it may ensure, at the cell level, an exquisite coordination between sensing of energy resources and the fundamental biological process of genome division.
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- 2009
- Full Text
- View/download PDF
9. Genome-wide inhibitory impact of the AMPK activator metformin on [kinesins, tubulins, histones, auroras and polo-like kinases] M-phase cell cycle genes in human breast cancer cells.
- Author
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Oliveras-Ferraros C, Vazquez-Martin A, and Menendez JA
- Subjects
- Aurora Kinases, Breast Neoplasms metabolism, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Cell Line, Tumor, Histones genetics, Histones metabolism, Humans, Kinesins genetics, Kinesins metabolism, Protein Serine-Threonine Kinases metabolism, Signal Transduction, Tubulin genetics, Tubulin metabolism, AMP-Activated Protein Kinases metabolism, Breast Neoplasms genetics, Breast Neoplasms pathology, Cell Division genetics, Gene Expression Regulation, Neoplastic genetics, Genome, Human genetics, Metformin metabolism
- Abstract
Prompted by the ever-growing scientific rationale for examining the antidiabetic drug metformin as a potential antitumor agent in breast cancer disease, we recently tested the hypothesis that the assessment of metformin-induced global changes in gene expression-as identified using 44 K (double density) Agilent's whole human genome arrays-could reveal gene-expression signatures that would allow proper selection of breast cancer patients who should be considered for metformin-based clinical trials. Using Database for Annotation, Visualization and Integrated Discovery bioinformatics (DAVID) resources we herein reveal that, at doses that lead to activation of the AMP-activated protein kinase (AMPK), metformin not only downregulates genes coding for ribosomal proteins (i.e., protein and macromolecule biosynthesis) but unexpectedly suppresses numerous mitosis-related gene families including kinesins, tubulins, histones, auroras and polo-like kinases. This is, to our knowledge, the first genome-scale evidence of a mitotic core component in the transcriptional response of human breast cancer cells to metformin. These findings further support a tight relationship between the activation status of AMPK and the chromosomal and cytoskeletal checkpoints of cell mitosis at the transcriptional level.
- Published
- 2009
- Full Text
- View/download PDF
10. Mitotic kinase dynamics of the active form of AMPK (phospho-AMPKalphaThr172) in human cancer cells.
- Author
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Vazquez-Martin A, López-Bonet E, Oliveras-Ferraros C, Pérez-Martínez MC, Bernadó L, and Menendez JA
- Subjects
- Aurora Kinase B, Aurora Kinases, Cell Line, Tumor, Chromosomal Proteins, Non-Histone metabolism, G1 Phase, Histones metabolism, Humans, Phosphorylation, Protein Serine-Threonine Kinases metabolism, S Phase, AMP-Activated Protein Kinases metabolism, Mitosis, Neoplasms enzymology
- Abstract
When interrogating the activation status of AMP-activated protein kinase-measured as AMPKalpha(Thr172) phosphorylation-in tissue sections of human carcinomas and in cultured human cancer cells, the spatiotemporal dynamics of AMPK activity during the G(1)/S-to-M-phase transition strikingly resembles that of well-characterized "chromosomal passenger" proteins such as Aurora B, INCENP or Histone H3. The mitotic kinase behavior of the active form of AMPK may represent a candidate molecular link through which energy status directly influences tumorigenesis. A definitive elucidation of phospho-AMPKalpha(Thr172) in coordinating the chromosomal and cytoskeletal events of mitosis might radically amend our current perception of other AMPK-related diseases such as obesity, cardiac hypertrophy or accelerated aging syndromes.
- Published
- 2009
- Full Text
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11. AMPK-sensed cellular energy state regulates the release of extracellular Fatty Acid Synthase.
- Author
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Oliveras-Ferraros C, Vazquez-Martin A, Fernández-Real JM, and Menendez JA
- Subjects
- AMP-Activated Protein Kinases antagonists & inhibitors, AMP-Activated Protein Kinases genetics, Aminoimidazole Carboxamide analogs & derivatives, Aminoimidazole Carboxamide pharmacology, Antibodies, Monoclonal immunology, Cell Line, Tumor, Culture Media, Conditioned, Cytosol enzymology, Energy Metabolism, Fatty Acid Synthase, Type I antagonists & inhibitors, Fatty Acid Synthase, Type I immunology, Humans, Isoenzymes antagonists & inhibitors, Isoenzymes immunology, Isoenzymes metabolism, Neoplasms enzymology, RNA, Small Interfering genetics, Ribonucleotides pharmacology, AMP-Activated Protein Kinases metabolism, Adenosine Monophosphate metabolism, Adenosine Triphosphate metabolism, Fatty Acid Synthase, Type I metabolism
- Abstract
Fatty Acid Synthase (FASN), a 250-kDa cytosolic multi-enzyme catalyzing eukaryotic de novo FA biogenesis, unexpectedly localizes in cancer cell culture supernatants and in the blood of cancer patients. High levels of "extracellular FASN" have recently been found in supernatants from Hepatitis C Virus-infected liver cells. The ultimate mechanism regulating FASN release, however, remained completely undefined. When the AMPK-activating drug AICAR was used to simulate an elevated AMP/ATP ratio in breast cancer cells, ELISA-based analyses revealed that extracellular FASN dramatically augmented in a dose- and time-dependent manner. Immunoblotting procedures using a battery of anti-FASN antibodies further confirmed that, in response to AMPK activation, FASN protein is depleted from the cytosol to accumulate as different FASN isoforms in the extracellular milieu. siRNA-induced blockade of AMPK expression largely attenuated AICAR-promoted FASN release. FASN release might represent a previously unrecognized mechanism through which AMPK monitor and restores cellular energy state in response to increasing AMP/ATP ratios.
- Published
- 2009
- Full Text
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