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Anton Simeonov - One of the best experts on this subject based on the ideXlab platform.
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inhibitors of the apurinic apyrimidinic endonuclease 1 ape1 nucleophosmin NPM1 interaction that display anti tumor properties
Molecular Carcinogenesis, 2016Co-Authors: Mattia Poletto, Pasqualina Liana Scognamiglio, Daniela Marasco, Matilde Clarissa Malfatti, Dorjbal Dorjsuren, Carlo Vascotto, Ajit Jadhav, David J Maloney, David M Wilson, Anton SimeonovAbstract:The apurinic/apyrimidinic endonuclease 1 (APE1) is a protein central to the base excision DNA repair pathway and operates in the modulation of gene expression through redox-dependent and independent mechanisms. Aberrant expression and localization of APE1 in tumors are recurrent hallmarks of aggressiveness and resistance to therapy. We identified and characterized the molecular association between APE1 and nucleophosmin (NPM1), a multifunctional protein involved in the preservation of genome stability and rRNA maturation. This protein–protein interaction modulates subcellular localization and endonuclease activity of APE1. Moreover, we reported a correlation between APE1 and NPM1 expression levels in ovarian cancer, with NPM1 overexpression being a marker of poor prognosis. These observations suggest that tumors that display an augmented APE1/NPM1 association may exhibit increased aggressiveness and resistance. Therefore, targeting the APE1/NPM1 interaction might represent an innovative strategy for the development of anticancer drugs, as tumor cells relying on higher levels of APE1 and NPM1 for proliferation and survival may be more sensitive than untransformed cells. We set up a chemiluminescence-based high-throughput screening assay in order to find small molecules able to interfere with the APE1/NPM1 interaction. This screening led to the identification of a set of bioactive compounds that impair the APE1/NPM1 association in living cells. Interestingly, some of these molecules display anti-proliferative activity and sensitize cells to therapeutically relevant genotoxins. Given the prognostic significance of APE1 and NPM1, these compounds might prove effective in the treatment of tumors that show abundant levels of both proteins, such as ovarian or hepatic carcinomas. © 2015 Wiley Periodicals, Inc.
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inhibitors of the apurinic apyrimidinic endonuclease 1 ape1 nucleophosmin NPM1 interaction that display anti tumor properties
Molecular Carcinogenesis, 2016Co-Authors: Mattia Poletto, Pasqualina Liana Scognamiglio, Daniela Marasco, Matilde Clarissa Malfatti, Dorjbal Dorjsuren, Carlo Vascotto, Ajit Jadhav, David J Maloney, David M Wilson, Anton SimeonovAbstract:The apurinic/apyrimidinic endonuclease 1 (APE1) is a protein central to the base excision DNA repair pathway and operates in the modulation of gene expression through redox-dependent and independent mechanisms. Aberrant expression and localization of APE1 in tumors are recurrent hallmarks of aggressiveness and resistance to therapy. We identified and characterized the molecular association between APE1 and nucleophosmin (NPM1), a multifunctional protein involved in the preservation of genome stability and rRNA maturation. This protein-protein interaction modulates subcellular localization and endonuclease activity of APE1. Moreover, we reported a correlation between APE1 and NPM1 expression levels in ovarian cancer, with NPM1 overexpression being a marker of poor prognosis. These observations suggest that tumors that display an augmented APE1/NPM1 association may exhibit increased aggressiveness and resistance. Therefore, targeting the APE1/NPM1 interaction might represent an innovative strategy for the development of anticancer drugs, as tumor cells relying on higher levels of APE1 and NPM1 for proliferation and survival may be more sensitive than untransformed cells. We set up a chemiluminescence-based high-throughput screening assay in order to find small molecules able to interfere with the APE1/NPM1 interaction. This screening led to the identification of a set of bioactive compounds that impair the APE1/NPM1 association in living cells. Interestingly, some of these molecules display anti-proliferative activity and sensitize cells to therapeutically relevant genotoxins. Given the prognostic significance of APE1 and NPM1, these compounds might prove effective in the treatment of tumors that show abundant levels of both proteins, such as ovarian or hepatic carcinomas.
Mattia Poletto - One of the best experts on this subject based on the ideXlab platform.
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inhibitors of the apurinic apyrimidinic endonuclease 1 ape1 nucleophosmin NPM1 interaction that display anti tumor properties
Molecular Carcinogenesis, 2016Co-Authors: Mattia Poletto, Pasqualina Liana Scognamiglio, Daniela Marasco, Matilde Clarissa Malfatti, Dorjbal Dorjsuren, Carlo Vascotto, Ajit Jadhav, David J Maloney, David M Wilson, Anton SimeonovAbstract:The apurinic/apyrimidinic endonuclease 1 (APE1) is a protein central to the base excision DNA repair pathway and operates in the modulation of gene expression through redox-dependent and independent mechanisms. Aberrant expression and localization of APE1 in tumors are recurrent hallmarks of aggressiveness and resistance to therapy. We identified and characterized the molecular association between APE1 and nucleophosmin (NPM1), a multifunctional protein involved in the preservation of genome stability and rRNA maturation. This protein-protein interaction modulates subcellular localization and endonuclease activity of APE1. Moreover, we reported a correlation between APE1 and NPM1 expression levels in ovarian cancer, with NPM1 overexpression being a marker of poor prognosis. These observations suggest that tumors that display an augmented APE1/NPM1 association may exhibit increased aggressiveness and resistance. Therefore, targeting the APE1/NPM1 interaction might represent an innovative strategy for the development of anticancer drugs, as tumor cells relying on higher levels of APE1 and NPM1 for proliferation and survival may be more sensitive than untransformed cells. We set up a chemiluminescence-based high-throughput screening assay in order to find small molecules able to interfere with the APE1/NPM1 interaction. This screening led to the identification of a set of bioactive compounds that impair the APE1/NPM1 association in living cells. Interestingly, some of these molecules display anti-proliferative activity and sensitize cells to therapeutically relevant genotoxins. Given the prognostic significance of APE1 and NPM1, these compounds might prove effective in the treatment of tumors that show abundant levels of both proteins, such as ovarian or hepatic carcinomas.
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inhibitors of the apurinic apyrimidinic endonuclease 1 ape1 nucleophosmin NPM1 interaction that display anti tumor properties
Molecular Carcinogenesis, 2016Co-Authors: Mattia Poletto, Pasqualina Liana Scognamiglio, Daniela Marasco, Matilde Clarissa Malfatti, Dorjbal Dorjsuren, Carlo Vascotto, Ajit Jadhav, David J Maloney, David M Wilson, Anton SimeonovAbstract:The apurinic/apyrimidinic endonuclease 1 (APE1) is a protein central to the base excision DNA repair pathway and operates in the modulation of gene expression through redox-dependent and independent mechanisms. Aberrant expression and localization of APE1 in tumors are recurrent hallmarks of aggressiveness and resistance to therapy. We identified and characterized the molecular association between APE1 and nucleophosmin (NPM1), a multifunctional protein involved in the preservation of genome stability and rRNA maturation. This protein–protein interaction modulates subcellular localization and endonuclease activity of APE1. Moreover, we reported a correlation between APE1 and NPM1 expression levels in ovarian cancer, with NPM1 overexpression being a marker of poor prognosis. These observations suggest that tumors that display an augmented APE1/NPM1 association may exhibit increased aggressiveness and resistance. Therefore, targeting the APE1/NPM1 interaction might represent an innovative strategy for the development of anticancer drugs, as tumor cells relying on higher levels of APE1 and NPM1 for proliferation and survival may be more sensitive than untransformed cells. We set up a chemiluminescence-based high-throughput screening assay in order to find small molecules able to interfere with the APE1/NPM1 interaction. This screening led to the identification of a set of bioactive compounds that impair the APE1/NPM1 association in living cells. Interestingly, some of these molecules display anti-proliferative activity and sensitize cells to therapeutically relevant genotoxins. Given the prognostic significance of APE1 and NPM1, these compounds might prove effective in the treatment of tumors that show abundant levels of both proteins, such as ovarian or hepatic carcinomas. © 2015 Wiley Periodicals, Inc.
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g quadruplex dna recognition by nucleophosmin new insights from protein dissection
Biochimica et Biophysica Acta, 2014Co-Authors: Pasqualina Liana Scognamiglio, Concetta Di Natale, Marilisa Leone, Mattia Poletto, Luigi Vitagliano, Gianluca Tell, Daniela MarascoAbstract:Abstract Background Nucleophosmin (NPM1, B23) is a multifunctional protein that is involved in a variety of fundamental biological processes. NPM1/B23 deregulation is implicated in the pathogenesis of several human malignancies. This protein exerts its functions through the interaction with a multiplicity of biological partners. Very recently it is has been shown that NPM1/B23 specifically recognizes DNA G-quadruplexes through its C-terminal region. Methods Through a rational dissection approach of protein here we show that the intrinsically unfolded regions of NPM1/B23 significantly contribute to the binding of c-MYC G-quadruplex motif. Interestingly, the analysis of the ability of distinct NPM1/B23 fragments to bind this quadruplex led to the identifications of distinct NPM1/B23-based peptides that individually present a high affinity for this motif. Results These results suggest that the tight binding of NPM1/B23 to the G-quadruplex is achieved through the cooperation of both folded and unfolded regions that are individually able to bind it. The dissection of NPM1/B23 also unveils that its H1 helix is intrinsically endowed with an unusual thermal stability. Conclusions These findings have implications for the unfolding mechanism of NPM1/B23, for the G-quadruplex affinity of the different NPM1/B23 isoforms and for the design of peptide-based molecules able to interact with this DNA motif. General observation This study sheds new light in the molecular mechanism of the complex NPM1/G-quadruplex involved in acute myeloid leukemia (AML) disease.
Pier Paolo Pandolfi - One of the best experts on this subject based on the ideXlab platform.
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Macrophage Function is Regulated by NPM1-Mediated 2'-O-Methylation
2020Co-Authors: Paolo Sportoletti, John G. Clohessy, Daphna Nachmani, Luisa Riccardi, Arati Khanna-gupta, Jian Chen, Andrea Marra, Nancy Berliner, Pier Paolo PandolfiAbstract:The NPM1 gene is frequently a target of genetic alteration in hematological tumors, particularly of the myeloid lineage. Complete inactivation of NPM1 in the mouse disrupts primitive hematopoiesis and results in embryonic lethality. NPM1 heterozygosity produces features similar to those of MDS that progress to overt leukemia, and specific point mutations of NPM1 lead to bone marrow failure due to loss of hematopoietic stem cells. However, little is known about NPM1s role in mature, differentiated cells. Here we generated a conditional mouse mutant to inactivate NPM1 across the myelomonocytic lineage, and investigated its ability to influence macrophage maturation and function. We found that NPM1 is not required to maintain macrophage viability, while its loss in mature macrophages reduces production of reactive oxygen species, chemotactic properties and phagocytic capacity. Taking advantage of our recently established NPM1D180del mouse model of ribosome dysfunction and hematological disease, we identify cellular translation and rRNA 2-O-methlyation as a crucial element in controlling macrophage function. These analyses demonstrate a role for NPM1 in adult immune cells, and reveal the importance of translation regulation in macrophage function.
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up regulation of translation eukaryotic initiation factor 4e in nucleophosmin 1 haploinsufficient cells results in changes in ccaat enhancer binding protein α activity implications in myelodysplastic syndrome and acute myeloid leukemia
Journal of Biological Chemistry, 2012Co-Authors: Arati Khannagupta, Paolo Sportoletti, Pier Paolo Pandolfi, Nirmalee Abayasekara, Michelle Levine, Maria Virgilio, Stephanie Halene, Jeeyeong Jeong, Nancy BerlinerAbstract:Abstract NPM1 is a ubiquitously expressed nucleolar phosphoprotein, the gene for which maps to chromosome 5q35 in close proximity to a commonly deleted region associated with (del)5q, a type of myelodysplastic syndrome (MDS). This region is also a frequent target of deletions in de novo and therapy-related MDS/acute myeloid leukemia. Previous studies have shown that NPM1+/− mice develop an MDS-like disease that transforms to acute myeloid leukemia over time. To better understand the mechanism by which NPM1 haploinsufficiency causes an MDS phenotype, we generated factor-dependent myeloid cell lines from the bone marrow of NPM1+/+ and NPM1+/− mice and demonstrated compromised neutrophil-specific gene expression in the MNPM1+/− cells. We attribute these observations to increased levels of the shorter, dominant negative leukemogenic isoform (p30) of CCAAT enhancer-binding protein α (C/EBPα). We show that this increase is caused, in part, by elevated levels of the activated translation initiation factor eIF4E, overexpression of which also increases translation of C/EBPαp30 in HEK293 cells. In a positive feedback loop, eIF4E expression is further elevated both at the mRNA and protein levels by C/EBPαp30 but not by the full-length C/EBPαp42. Re-expression of C/EBPαp42 or NPM1 but not C/EBPαp30 in MNPM1+/− cells partially rescues the myeloid phenotype. Our observations suggest that the aberrant feed-forward pathway that keeps eIF4E and C/EBPαp30 elevated in NPM1+/− cells contributes to the MDS phenotype associated with NPM1 deficiency.
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up regulation of translation eukaryotic initiation factor 4e in nucleophosmin 1 haploinsufficient cells results in changes in ccaat enhancer binding protein α activity implications in myelodysplastic syndrome and acute myeloid leukemia
Journal of Biological Chemistry, 2012Co-Authors: Arati Khannagupta, Paolo Sportoletti, Nirmalee Abayasekara, Michelle Levine, Maria Virgilio, Stephanie Halene, Jeeyeong Jeong, Hong Sun, Navid Nia, Pier Paolo PandolfiAbstract:NPM1 is a ubiquitously expressed nucleolar phosphoprotein, the gene for which maps to chromosome 5q35 in close proximity to a commonly deleted region associated with (del)5q, a type of myelodysplastic syndrome (MDS). This region is also a frequent target of deletions in de novo and therapy-related MDS/acute myeloid leukemia. Previous studies have shown that NPM1+/− mice develop an MDS-like disease that transforms to acute myeloid leukemia over time. To better understand the mechanism by which NPM1 haploinsufficiency causes an MDS phenotype, we generated factor-dependent myeloid cell lines from the bone marrow of NPM1+/+ and NPM1+/− mice and demonstrated compromised neutrophil-specific gene expression in the MNPM1+/− cells. We attribute these observations to increased levels of the shorter, dominant negative leukemogenic isoform (p30) of CCAAT enhancer-binding protein α (C/EBPα). We show that this increase is caused, in part, by elevated levels of the activated translation initiation factor eIF4E, overexpression of which also increases translation of C/EBPαp30 in HEK293 cells. In a positive feedback loop, eIF4E expression is further elevated both at the mRNA and protein levels by C/EBPαp30 but not by the full-length C/EBPαp42. Re-expression of C/EBPαp42 or NPM1 but not C/EBPαp30 in MNPM1+/− cells partially rescues the myeloid phenotype. Our observations suggest that the aberrant feed-forward pathway that keeps eIF4E and C/EBPαp30 elevated in NPM1+/− cells contributes to the MDS phenotype associated with NPM1 deficiency.
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upregulation of eif4e in nucleophosmin 1 NPM1 haploinsufficient cells alters ccaat enhancer binding protein alpha c ebpα activity implications for mds and aml
Blood, 2011Co-Authors: Nirmalee Abayasekara, Paolo Sportoletti, Pier Paolo Pandolfi, Nancy Berliner, N Bolli, Michelle Levine, Hong Sun, Navid Nia, Matthew Silver, Arati KhannaguptaAbstract:Abstract 2432 NPM1 , is a highly conserved, ubiquitous nucleolar phosphoprotein that belongs to the nucleoplasmin family of nuclear chaperones. NPM1 −/− mice die at mid-gestation (E11.5) from anemia, underscoring the gene9s role in embryonic development. NPM1 is one of the most frequently mutated genes in AML. Mutations in NPM1 are found in 50% of normal karyotype AML patients, and mutant NPM1 (NPMc+) is aberrantly located in the cytoplasm of leukemic blasts in about 35% of all AML patients. Furthermore, NPM1 maps to a region on chromosome 5q that is the target of deletions in both de novo and therapy-associated human MDS. NPM1 thus acts as a haploinsufficient tumor suppressor in the hematological compartment, although the mechanism of its contribution to dysmyelopoiesis remains unknown. NPM-1 +/− mice develop a hematological syndrome similar to that observed in human MDS, and develop AML over time. The NPM1 deficient model therefore provides a platform to interrogate the molecular basis of MDS. We identified nucleophosmin ( NPM1 ) in a screen for protein binding partners of C/EBPα. C/EBPα is a single exon gene, but is expressed as two isoforms that arise by alternate translation start sites to yield a full length C/EBPα p42 and a truncated dominant negative C/EBPα p30 isoform. Translational control of isoform expression is orchestrated by a conserved upstream open reading frame (uORF) in the 59 untranslated region (59UTR) and modulated by the translation initiation factors eIF4E and eIF2. We generated factor-dependent myeloid cell lines from the bone marrow of NPM1 +/+ and NPM1 +/− mice. These lines are IL-3-dependent and inducible toward neutrophil maturation with GM-CSF and/ or all- trans retinoic acid (ATRA). Neutrophils derived from MNPM1 +/− cells display defective neutrophil-specific gene expression, including a cassette of C/EBPα-dependent genes. These observations led us to postulate that myeloid abnormalities in NPM1 deficiency reflect an aberrant NPM1-C/EBPα axis. We show that NPM1 haploinsufficiency upregulates eIF4E (eukaryotic initiation factor 4E) (but not eIF2), which binds the mRNA-Cap (m 7 -GTP) as part of the mRNA translation initiation complex, eIF4F. Increased eIF4E is observed in about 30% of all malignancies. Initial increased eIF4E levels in MNPM +/− cells likely reflect transcriptional activation by the oncoprotein c-Myc, protein levels of which are also elevated in MNPM1 +/− cells. We propose that increased eIF4E then induces increased C/EBPαp30 translation. C/EBPαp30 is a dominant negative inhibitor of full length C/EBPαp42 activity and disrupts normal neutrophil development. Furthermore, we demonstrate that C/EBPαp30 but not C/EBPαp42, activates the eIF4E promoter. We propose a positive feedback loop, wherein increased C/EBPαp30 induced by eIF4E further increases the expression of eIF4E. Our data suggest that NPM1 deficiency modulates neutrophil-specific gene expression by altering C/EBPα. We propose an aberrant feed-forward mechanism that increases levels of both eIF4E and C/EBPαp30 and likely contributes to MDS associated with NPM1 deficiency. Disclosures: No relevant conflicts of interest to declare.
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NPM1 is a haploinsufficient suppressor of myeloid and lymphoid malignancies in the mouse
Blood, 2008Co-Authors: Paolo Sportoletti, Samia M. Majid, John G. Clohessy, Andrea Viale, Julie Teruya-feldstein, Silvia Grisendi, Ke Cheng, Pier Paolo PandolfiAbstract:Nucleophosmin (NPM1) gene has been heavily implicated in cancer pathogenesis both as a putative proto-oncogene and tumor suppressor gene. NPM1 is the most frequently mutated gene in acute myeloid leukemia (AML), while deletion of 5q, where NPM1 maps, is frequent in patients with myelodysplastic syndromes (MDS). We have previously shown that mice heterozygous for NPM1 (NPM1+/-) develop a hematologic syndrome with features of human MDS. Here we analyzed NPM1+/- mutants to determine their susceptibility to cancer. NPM1+/- mice displayed a greater propensity to develop malignancies compared with NPM1+/+ mice. The NPM1+/- cohort frequently developed hematologic malignancies of both myeloid and lymphoid origin with myeloid malignancies displaying the highest incidence. Malignant cells retained the wild-type allele with normal localization and expression of NPM1 at the protein level, suggesting that complete NPM1 loss is not a prerequisite for tumorigenesis. Our results conclusively demonstrate that NPM1 acts as a haploinsufficient tumor suppressor in the hematopoietic compartment.
Pasqualina Liana Scognamiglio - One of the best experts on this subject based on the ideXlab platform.
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inhibitors of the apurinic apyrimidinic endonuclease 1 ape1 nucleophosmin NPM1 interaction that display anti tumor properties
Molecular Carcinogenesis, 2016Co-Authors: Mattia Poletto, Pasqualina Liana Scognamiglio, Daniela Marasco, Matilde Clarissa Malfatti, Dorjbal Dorjsuren, Carlo Vascotto, Ajit Jadhav, David J Maloney, David M Wilson, Anton SimeonovAbstract:The apurinic/apyrimidinic endonuclease 1 (APE1) is a protein central to the base excision DNA repair pathway and operates in the modulation of gene expression through redox-dependent and independent mechanisms. Aberrant expression and localization of APE1 in tumors are recurrent hallmarks of aggressiveness and resistance to therapy. We identified and characterized the molecular association between APE1 and nucleophosmin (NPM1), a multifunctional protein involved in the preservation of genome stability and rRNA maturation. This protein-protein interaction modulates subcellular localization and endonuclease activity of APE1. Moreover, we reported a correlation between APE1 and NPM1 expression levels in ovarian cancer, with NPM1 overexpression being a marker of poor prognosis. These observations suggest that tumors that display an augmented APE1/NPM1 association may exhibit increased aggressiveness and resistance. Therefore, targeting the APE1/NPM1 interaction might represent an innovative strategy for the development of anticancer drugs, as tumor cells relying on higher levels of APE1 and NPM1 for proliferation and survival may be more sensitive than untransformed cells. We set up a chemiluminescence-based high-throughput screening assay in order to find small molecules able to interfere with the APE1/NPM1 interaction. This screening led to the identification of a set of bioactive compounds that impair the APE1/NPM1 association in living cells. Interestingly, some of these molecules display anti-proliferative activity and sensitize cells to therapeutically relevant genotoxins. Given the prognostic significance of APE1 and NPM1, these compounds might prove effective in the treatment of tumors that show abundant levels of both proteins, such as ovarian or hepatic carcinomas.
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inhibitors of the apurinic apyrimidinic endonuclease 1 ape1 nucleophosmin NPM1 interaction that display anti tumor properties
Molecular Carcinogenesis, 2016Co-Authors: Mattia Poletto, Pasqualina Liana Scognamiglio, Daniela Marasco, Matilde Clarissa Malfatti, Dorjbal Dorjsuren, Carlo Vascotto, Ajit Jadhav, David J Maloney, David M Wilson, Anton SimeonovAbstract:The apurinic/apyrimidinic endonuclease 1 (APE1) is a protein central to the base excision DNA repair pathway and operates in the modulation of gene expression through redox-dependent and independent mechanisms. Aberrant expression and localization of APE1 in tumors are recurrent hallmarks of aggressiveness and resistance to therapy. We identified and characterized the molecular association between APE1 and nucleophosmin (NPM1), a multifunctional protein involved in the preservation of genome stability and rRNA maturation. This protein–protein interaction modulates subcellular localization and endonuclease activity of APE1. Moreover, we reported a correlation between APE1 and NPM1 expression levels in ovarian cancer, with NPM1 overexpression being a marker of poor prognosis. These observations suggest that tumors that display an augmented APE1/NPM1 association may exhibit increased aggressiveness and resistance. Therefore, targeting the APE1/NPM1 interaction might represent an innovative strategy for the development of anticancer drugs, as tumor cells relying on higher levels of APE1 and NPM1 for proliferation and survival may be more sensitive than untransformed cells. We set up a chemiluminescence-based high-throughput screening assay in order to find small molecules able to interfere with the APE1/NPM1 interaction. This screening led to the identification of a set of bioactive compounds that impair the APE1/NPM1 association in living cells. Interestingly, some of these molecules display anti-proliferative activity and sensitize cells to therapeutically relevant genotoxins. Given the prognostic significance of APE1 and NPM1, these compounds might prove effective in the treatment of tumors that show abundant levels of both proteins, such as ovarian or hepatic carcinomas. © 2015 Wiley Periodicals, Inc.
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g quadruplex dna recognition by nucleophosmin new insights from protein dissection
Biochimica et Biophysica Acta, 2014Co-Authors: Pasqualina Liana Scognamiglio, Concetta Di Natale, Marilisa Leone, Mattia Poletto, Luigi Vitagliano, Gianluca Tell, Daniela MarascoAbstract:Abstract Background Nucleophosmin (NPM1, B23) is a multifunctional protein that is involved in a variety of fundamental biological processes. NPM1/B23 deregulation is implicated in the pathogenesis of several human malignancies. This protein exerts its functions through the interaction with a multiplicity of biological partners. Very recently it is has been shown that NPM1/B23 specifically recognizes DNA G-quadruplexes through its C-terminal region. Methods Through a rational dissection approach of protein here we show that the intrinsically unfolded regions of NPM1/B23 significantly contribute to the binding of c-MYC G-quadruplex motif. Interestingly, the analysis of the ability of distinct NPM1/B23 fragments to bind this quadruplex led to the identifications of distinct NPM1/B23-based peptides that individually present a high affinity for this motif. Results These results suggest that the tight binding of NPM1/B23 to the G-quadruplex is achieved through the cooperation of both folded and unfolded regions that are individually able to bind it. The dissection of NPM1/B23 also unveils that its H1 helix is intrinsically endowed with an unusual thermal stability. Conclusions These findings have implications for the unfolding mechanism of NPM1/B23, for the G-quadruplex affinity of the different NPM1/B23 isoforms and for the design of peptide-based molecules able to interact with this DNA motif. General observation This study sheds new light in the molecular mechanism of the complex NPM1/G-quadruplex involved in acute myeloid leukemia (AML) disease.
Daniela Marasco - One of the best experts on this subject based on the ideXlab platform.
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inhibitors of the apurinic apyrimidinic endonuclease 1 ape1 nucleophosmin NPM1 interaction that display anti tumor properties
Molecular Carcinogenesis, 2016Co-Authors: Mattia Poletto, Pasqualina Liana Scognamiglio, Daniela Marasco, Matilde Clarissa Malfatti, Dorjbal Dorjsuren, Carlo Vascotto, Ajit Jadhav, David J Maloney, David M Wilson, Anton SimeonovAbstract:The apurinic/apyrimidinic endonuclease 1 (APE1) is a protein central to the base excision DNA repair pathway and operates in the modulation of gene expression through redox-dependent and independent mechanisms. Aberrant expression and localization of APE1 in tumors are recurrent hallmarks of aggressiveness and resistance to therapy. We identified and characterized the molecular association between APE1 and nucleophosmin (NPM1), a multifunctional protein involved in the preservation of genome stability and rRNA maturation. This protein-protein interaction modulates subcellular localization and endonuclease activity of APE1. Moreover, we reported a correlation between APE1 and NPM1 expression levels in ovarian cancer, with NPM1 overexpression being a marker of poor prognosis. These observations suggest that tumors that display an augmented APE1/NPM1 association may exhibit increased aggressiveness and resistance. Therefore, targeting the APE1/NPM1 interaction might represent an innovative strategy for the development of anticancer drugs, as tumor cells relying on higher levels of APE1 and NPM1 for proliferation and survival may be more sensitive than untransformed cells. We set up a chemiluminescence-based high-throughput screening assay in order to find small molecules able to interfere with the APE1/NPM1 interaction. This screening led to the identification of a set of bioactive compounds that impair the APE1/NPM1 association in living cells. Interestingly, some of these molecules display anti-proliferative activity and sensitize cells to therapeutically relevant genotoxins. Given the prognostic significance of APE1 and NPM1, these compounds might prove effective in the treatment of tumors that show abundant levels of both proteins, such as ovarian or hepatic carcinomas.
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inhibitors of the apurinic apyrimidinic endonuclease 1 ape1 nucleophosmin NPM1 interaction that display anti tumor properties
Molecular Carcinogenesis, 2016Co-Authors: Mattia Poletto, Pasqualina Liana Scognamiglio, Daniela Marasco, Matilde Clarissa Malfatti, Dorjbal Dorjsuren, Carlo Vascotto, Ajit Jadhav, David J Maloney, David M Wilson, Anton SimeonovAbstract:The apurinic/apyrimidinic endonuclease 1 (APE1) is a protein central to the base excision DNA repair pathway and operates in the modulation of gene expression through redox-dependent and independent mechanisms. Aberrant expression and localization of APE1 in tumors are recurrent hallmarks of aggressiveness and resistance to therapy. We identified and characterized the molecular association between APE1 and nucleophosmin (NPM1), a multifunctional protein involved in the preservation of genome stability and rRNA maturation. This protein–protein interaction modulates subcellular localization and endonuclease activity of APE1. Moreover, we reported a correlation between APE1 and NPM1 expression levels in ovarian cancer, with NPM1 overexpression being a marker of poor prognosis. These observations suggest that tumors that display an augmented APE1/NPM1 association may exhibit increased aggressiveness and resistance. Therefore, targeting the APE1/NPM1 interaction might represent an innovative strategy for the development of anticancer drugs, as tumor cells relying on higher levels of APE1 and NPM1 for proliferation and survival may be more sensitive than untransformed cells. We set up a chemiluminescence-based high-throughput screening assay in order to find small molecules able to interfere with the APE1/NPM1 interaction. This screening led to the identification of a set of bioactive compounds that impair the APE1/NPM1 association in living cells. Interestingly, some of these molecules display anti-proliferative activity and sensitize cells to therapeutically relevant genotoxins. Given the prognostic significance of APE1 and NPM1, these compounds might prove effective in the treatment of tumors that show abundant levels of both proteins, such as ovarian or hepatic carcinomas. © 2015 Wiley Periodicals, Inc.
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g quadruplex dna recognition by nucleophosmin new insights from protein dissection
Biochimica et Biophysica Acta, 2014Co-Authors: Pasqualina Liana Scognamiglio, Concetta Di Natale, Marilisa Leone, Mattia Poletto, Luigi Vitagliano, Gianluca Tell, Daniela MarascoAbstract:Abstract Background Nucleophosmin (NPM1, B23) is a multifunctional protein that is involved in a variety of fundamental biological processes. NPM1/B23 deregulation is implicated in the pathogenesis of several human malignancies. This protein exerts its functions through the interaction with a multiplicity of biological partners. Very recently it is has been shown that NPM1/B23 specifically recognizes DNA G-quadruplexes through its C-terminal region. Methods Through a rational dissection approach of protein here we show that the intrinsically unfolded regions of NPM1/B23 significantly contribute to the binding of c-MYC G-quadruplex motif. Interestingly, the analysis of the ability of distinct NPM1/B23 fragments to bind this quadruplex led to the identifications of distinct NPM1/B23-based peptides that individually present a high affinity for this motif. Results These results suggest that the tight binding of NPM1/B23 to the G-quadruplex is achieved through the cooperation of both folded and unfolded regions that are individually able to bind it. The dissection of NPM1/B23 also unveils that its H1 helix is intrinsically endowed with an unusual thermal stability. Conclusions These findings have implications for the unfolding mechanism of NPM1/B23, for the G-quadruplex affinity of the different NPM1/B23 isoforms and for the design of peptide-based molecules able to interact with this DNA motif. General observation This study sheds new light in the molecular mechanism of the complex NPM1/G-quadruplex involved in acute myeloid leukemia (AML) disease.
