V. Trapani - Academia.edu (original) (raw)
Papers by V. Trapani
Molecular Pharmacology, 2002
2-(4-Amino-3-methylphenyl) benzothiazole (NSC 674495; DF 203) demonstrates drug uptake and metabo... more 2-(4-Amino-3-methylphenyl) benzothiazole (NSC 674495; DF 203) demonstrates drug uptake and metabolism by tumor cells sensitive to the antiproliferative activity of the drug [J Med Chem 1999;42:4172-4184]. In insensitive cells, little metabolism occurs. Because CYP1A1 can metabolize DF 203, the aryl hydrocarbon receptor (AhR) may mediate drug action. We demonstrate here that DF 203 increases CYP1A1 and CYP1B1 transcription in sensitive MCF-7 cells, accompanied by AhR translocation to the nucleus, increase in xenobiotic-responsive element (XRE)-driven luciferase activity, and induction of protein/DNA complexes on the XRE sequence of the CYP1A1 promoter. MDA-MB-435 and PC3 cells, resistant to DF 203, did not show drug-induced CYP1A1 and CYP1B1 gene expression. AhR was observed to be constitutively localized in the nucleus, with no induction of XRE-driven luciferase activity in transiently transfected cells and weak or no induction of protein/DNA complexes on the XRE sequence of CYP1A1. Taken together, these data elucidate a novel basis for antitumor drug action: induction in sensitive cells of a metabolizing system for the drug itself. These results suggest that clarification of the basis for differential engagement of AhR-related signaling in different tumor cell types may aid in further preclinical development and perhaps early clinical studies.
ABSTRACT Although magnesium ions play a key role in many fundamental biological processes, inform... more ABSTRACT Although magnesium ions play a key role in many fundamental biological processes, information about its intracellular regulation is still scarce, due to the lack of appropriate detection methods. Here, we report the spectroscopic characterization of two diaza-18-crown-6 hydroxyquinoline derivatives (DCHQ) and we propose their application for the determination of total Mg2+ concentration and in confocal imaging as effective Mg2+ indicators. DCHQ derivatives 1 and 2 bind Mg2+ with much higher affinity than other available probes (Kd = 44 and 73 mM, respectively) with a concomitant strong fluorescence increase. On the other hand, the fluorescence intensity is not significantly affected by other divalent cations, most importantly Ca2+, or by pH changes within the physiological range. Evidence is provided on the use of fluorometric data to derive totalcellular Mg2+content, which is in agreement with atomic absorption data. Furthermore, we show that DCHQ compounds can be effectively employed to map intracellular ion distribution and movements in live cells by confocal microscopy. These findings suggest that DCHQ derivatives may serve as new probes for the study of Mg2+ regulation, allowing sensitive and straightforward detection of both static and dynamic signals.
Chemical Science, 2012
... intracellular magnesium†. Chiara Marraccini*a, Giovanna Farruggiab, Marco Lombardoc, Luca Pro... more ... intracellular magnesium†. Chiara Marraccini*a, Giovanna Farruggiab, Marco Lombardoc, Luca Prodic, Massimo Sgarzic, Valentina Trapanid, Claudio Trombinic, Federica I. Wolfd, Nelsi Zaccheronic and Stefano Iotti*ae. a Università ...
The Analyst, 2010
A wide variety of biochemical reactions and physiological functions are known to require magnesiu... more A wide variety of biochemical reactions and physiological functions are known to require magnesium; nonetheless, its regulatory mechanisms (both at the cellular and systemic level) are still poorly characterised. Derangement of magnesium homeostasis is associated with several relevant human pathologies, e.g. diabetes, neuromuscular disorders, hypertension and other cardiovascular diseases. The study of the regulation of magnesium has gained particular interest in the last decades thanks to the molecular characterisation of specific magnesium transporters and the exploitation of molecular biology techniques to clarify their cellular and physiological function(s). In contrast, experimental tools to trace cellular magnesium and to define its homeostasis in living cells have not witnessed a corresponding progress. It was not until recently that efforts were paid to design more appropriate fluorescent indicators that could translate the advances of live imaging techniques into the field of magnesium research. Herein we critically summarise the state of the art in intracellular magnesium detection by fluorescent probes and focus on the need for improving methods and techniques in this area. We highlight the advantages of last-generation fluorescent indicators and discuss a number of challenges and opportunities that the development of novel and better sensors for magnesium still faces.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2011
We report a novel experimental approach to derive quantitative concentration map of light element... more We report a novel experimental approach to derive quantitative concentration map of light elements in whole cells by combining two complementary nano-probe methods: X-ray fluorescence microscopy (XRFM) and atomic force microscopy (AFM). The concentration ...
Human Mutation, 2014
A 0.8 kb intronic duplication in MAGT1 and a single base pair deletion in the last exon of ATRX w... more A 0.8 kb intronic duplication in MAGT1 and a single base pair deletion in the last exon of ATRX were identified using a chromosome X-specific microarray and exome sequencing in a family with five males demonstrating intellectual disability (ID) and unusual skin findings (e.g., generalized pruritus). MAGT1 is an Mg²⁺ transporter previously associated with primary immunodeficiency and ID, whereas mutations in ATRX cause ATRX-ID syndrome. In patient cells, the function of ATRX was demonstrated to be abnormal based on altered RNA/protein expression, hypomethylation of rDNA, and abnormal cytokinesis. Dysfunction of MAGT1 was reflected in reduced RNA/protein expression and Mg²⁺ influx. The mutation in ATRX most likely explains the ID, whereas MAGT1 disruption could be linked to abnormal skin findings, as normal magnesium homeostasis is necessary for skin health. This work supports observations that multiple mutations collectively contribute to the phenotypic variability of syndromic ID, and emphasizes the importance of correlating clinical phenotype with genomic and cell function analyses.
We present in this paper a novel methodology that combines scanning x-ray fluorescencee microscop... more We present in this paper a novel methodology that combines scanning x-ray fluorescencee microscopy and atomic force microscopy. The combination of these two techniques allows the determination of a concentration map of Mg in whole (not sectioned) cells.
Magnesium is the most abundant intracellular divalent cation. We present an innovative experiment... more Magnesium is the most abundant intracellular divalent cation. We present an innovative experimental approach to localizing intracellular magnesium that combines elemental and morphological information from individual cells with high-resolution spatial information. Integration of information from scanning fluorescence X-ray microscopy with information from atomic force microscopy was used to generate a magnesium concentration map and to determine the X-ray linear absorption
Molecular Pharmacology, 2002
2-(4-Amino-3-methylphenyl) benzothiazole (NSC 674495; DF 203) demonstrates drug uptake and metabo... more 2-(4-Amino-3-methylphenyl) benzothiazole (NSC 674495; DF 203) demonstrates drug uptake and metabolism by tumor cells sensitive to the antiproliferative activity of the drug [J Med Chem 1999;42:4172-4184]. In insensitive cells, little metabolism occurs. Because CYP1A1 can metabolize DF 203, the aryl hydrocarbon receptor (AhR) may mediate drug action. We demonstrate here that DF 203 increases CYP1A1 and CYP1B1 transcription in sensitive MCF-7 cells, accompanied by AhR translocation to the nucleus, increase in xenobiotic-responsive element (XRE)-driven luciferase activity, and induction of protein/DNA complexes on the XRE sequence of the CYP1A1 promoter. MDA-MB-435 and PC3 cells, resistant to DF 203, did not show drug-induced CYP1A1 and CYP1B1 gene expression. AhR was observed to be constitutively localized in the nucleus, with no induction of XRE-driven luciferase activity in transiently transfected cells and weak or no induction of protein/DNA complexes on the XRE sequence of CYP1A1. Taken together, these data elucidate a novel basis for antitumor drug action: induction in sensitive cells of a metabolizing system for the drug itself. These results suggest that clarification of the basis for differential engagement of AhR-related signaling in different tumor cell types may aid in further preclinical development and perhaps early clinical studies.
ABSTRACT Although magnesium ions play a key role in many fundamental biological processes, inform... more ABSTRACT Although magnesium ions play a key role in many fundamental biological processes, information about its intracellular regulation is still scarce, due to the lack of appropriate detection methods. Here, we report the spectroscopic characterization of two diaza-18-crown-6 hydroxyquinoline derivatives (DCHQ) and we propose their application for the determination of total Mg2+ concentration and in confocal imaging as effective Mg2+ indicators. DCHQ derivatives 1 and 2 bind Mg2+ with much higher affinity than other available probes (Kd = 44 and 73 mM, respectively) with a concomitant strong fluorescence increase. On the other hand, the fluorescence intensity is not significantly affected by other divalent cations, most importantly Ca2+, or by pH changes within the physiological range. Evidence is provided on the use of fluorometric data to derive totalcellular Mg2+content, which is in agreement with atomic absorption data. Furthermore, we show that DCHQ compounds can be effectively employed to map intracellular ion distribution and movements in live cells by confocal microscopy. These findings suggest that DCHQ derivatives may serve as new probes for the study of Mg2+ regulation, allowing sensitive and straightforward detection of both static and dynamic signals.
Chemical Science, 2012
... intracellular magnesium†. Chiara Marraccini*a, Giovanna Farruggiab, Marco Lombardoc, Luca Pro... more ... intracellular magnesium†. Chiara Marraccini*a, Giovanna Farruggiab, Marco Lombardoc, Luca Prodic, Massimo Sgarzic, Valentina Trapanid, Claudio Trombinic, Federica I. Wolfd, Nelsi Zaccheronic and Stefano Iotti*ae. a Università ...
The Analyst, 2010
A wide variety of biochemical reactions and physiological functions are known to require magnesiu... more A wide variety of biochemical reactions and physiological functions are known to require magnesium; nonetheless, its regulatory mechanisms (both at the cellular and systemic level) are still poorly characterised. Derangement of magnesium homeostasis is associated with several relevant human pathologies, e.g. diabetes, neuromuscular disorders, hypertension and other cardiovascular diseases. The study of the regulation of magnesium has gained particular interest in the last decades thanks to the molecular characterisation of specific magnesium transporters and the exploitation of molecular biology techniques to clarify their cellular and physiological function(s). In contrast, experimental tools to trace cellular magnesium and to define its homeostasis in living cells have not witnessed a corresponding progress. It was not until recently that efforts were paid to design more appropriate fluorescent indicators that could translate the advances of live imaging techniques into the field of magnesium research. Herein we critically summarise the state of the art in intracellular magnesium detection by fluorescent probes and focus on the need for improving methods and techniques in this area. We highlight the advantages of last-generation fluorescent indicators and discuss a number of challenges and opportunities that the development of novel and better sensors for magnesium still faces.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2011
We report a novel experimental approach to derive quantitative concentration map of light element... more We report a novel experimental approach to derive quantitative concentration map of light elements in whole cells by combining two complementary nano-probe methods: X-ray fluorescence microscopy (XRFM) and atomic force microscopy (AFM). The concentration ...
Human Mutation, 2014
A 0.8 kb intronic duplication in MAGT1 and a single base pair deletion in the last exon of ATRX w... more A 0.8 kb intronic duplication in MAGT1 and a single base pair deletion in the last exon of ATRX were identified using a chromosome X-specific microarray and exome sequencing in a family with five males demonstrating intellectual disability (ID) and unusual skin findings (e.g., generalized pruritus). MAGT1 is an Mg²⁺ transporter previously associated with primary immunodeficiency and ID, whereas mutations in ATRX cause ATRX-ID syndrome. In patient cells, the function of ATRX was demonstrated to be abnormal based on altered RNA/protein expression, hypomethylation of rDNA, and abnormal cytokinesis. Dysfunction of MAGT1 was reflected in reduced RNA/protein expression and Mg²⁺ influx. The mutation in ATRX most likely explains the ID, whereas MAGT1 disruption could be linked to abnormal skin findings, as normal magnesium homeostasis is necessary for skin health. This work supports observations that multiple mutations collectively contribute to the phenotypic variability of syndromic ID, and emphasizes the importance of correlating clinical phenotype with genomic and cell function analyses.
We present in this paper a novel methodology that combines scanning x-ray fluorescencee microscop... more We present in this paper a novel methodology that combines scanning x-ray fluorescencee microscopy and atomic force microscopy. The combination of these two techniques allows the determination of a concentration map of Mg in whole (not sectioned) cells.
Magnesium is the most abundant intracellular divalent cation. We present an innovative experiment... more Magnesium is the most abundant intracellular divalent cation. We present an innovative experimental approach to localizing intracellular magnesium that combines elemental and morphological information from individual cells with high-resolution spatial information. Integration of information from scanning fluorescence X-ray microscopy with information from atomic force microscopy was used to generate a magnesium concentration map and to determine the X-ray linear absorption