In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and mainte... more In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and maintenance of stem-like/aggressive features in prostate cancer (PCa) cells comparing zoledronic acid (ZA)-resistant DU145R80 with their parental DU145 cells. ANXA1 is over-expressed in DU145R80 cells and its down-regulation abolishes their resistance to ZA. Moreover, ANXA1 induces DU145 and DU145R80 invasiveness acting through formyl peptide receptors (FPRs). Also, ANXA1 knockdown is able to inhibit epithelial to mesenchymal transition (EMT) and to reduce focal adhesion kinase (FAK) and metalloproteases (MMP)-2/9 expression in PCa cells. DU145R80 show a cancer stem cell (CSC)-like signature with a high expression of CSC markers including CD44, CD133, NANOG, Snail, Oct4 and ALDH7A1 and CSC-related genes as STAT3. Interestingly, ANXA1 knockdown induces these cells to revert from a putative prostate CSC to a more differentiated phenotype resembling DU145 PCa cell signature. Similar results are obtained concerning some drug resistance-related genes such as ATP Binding Cassette G2 (ABCG2) and Lung Resistant Protein (LRP). Our study provides new insights on the role of ANXA1 protein in PCa onset and progression.
Tuberculosis is an increasing threat, owing to the spread of AIDS and to the development of resis... more Tuberculosis is an increasing threat, owing to the spread of AIDS and to the development of resistance of the causative organism, Mycobacterium tuberculosis, to the currently available drugs. Dihydrofolate reductase (DHFR) is an important enzyme of the folate cycle; inhibition of DHFR inhibits growth and causes cell death. The crystal structure of M. tuberculosis DHFR revealed a glycerol tightly bound close to the binding site for the substrate dihydrofolate; this glycerol-binding motif is absent from the human enzyme. A series of pyrimidine-2,4-diamines was designed with a two-carbon tether between a glycerol-mimicking triol and the 6-position of the heterocycle; these compounds also carried aryl substituents at the 5-position. These, their diastereoisomers, analogues lacking two hydroxy groups and analogues lacking the two-carbon spacing linker were synthesised by acylation of the anions derived from phenylacetonitriles with ethyl (4S,5R)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane-4-propanoate, ethyl (4S,5S)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane-4-propanoate, tetrahydrooxepin-2-one and 2,3-O-isopropylidene-d-erythronolactone, respectively, to give the corresponding alpha-acylphenylacetonitriles. Formation of the methyl enol ethers, condensation with guanidine and deprotection gave the pyrimidine-2,4-diamines. Preliminary assay of the abilities of these compounds to inhibit the growth of TB5 Saccharomyces cerevisiae carrying the DHFR genes from M. tuberculosis, human and yeast indicated that 5-phenyl-6-((3R,4S)-3,4,5-trihydroxypentyl)pyrimidine-2,4-diamine selectively inhibited M. tuberculosis DHFR and had little effect on the human or yeast enzymes.
Annexin A1 (ANXA1), a 37 kDa multifunctional protein, is over-expressed in tissues from patients ... more Annexin A1 (ANXA1), a 37 kDa multifunctional protein, is over-expressed in tissues from patients of pancreatic carcinoma (PC) where the protein seems to be associated with malignant transformation and poor prognosis. The expression and localization of ANXA1 in MIA PaCa-2, PANC-1, BxPC-3 and CAPAN-2 cells were detected by Western Blotting and Immunofluorescence assay. Expression and activation of Formyl Peptide Receptors (FPRs) were shown through flow cytometry/PCR and FURA assay, respectively. To investigate the role of ANXA1 in PC cell migration and invasion, we performed in vitro wound-healing and matrigel invasion assays. In all the analyzed PC cell lines, a huge expression and a variable localization of ANXA1 in sub-cellular compartments were observed. We confirmed the less aggressive phenotype of BxPC-3 and CAPAN-2 compared with PANC-1 and MIA PaCa-2 cells, through the evaluation of Epithelial-Mesenchymal Transition (EMT) markers. Then, we tested MIA PaCa-2 and PANC-1 cell migr...
Notch signaling plays a key role in virtually all tissues
and organs in metazoans; however, limi... more Notch signaling plays a key role in virtually all tissues
and organs in metazoans; however, limited examples are
available for the regulatory role of this pathway in adult
quiescent stem cells. We performed a temporal and ontological
assessment of effectors of the Notch pathway that
indicated highest activity in freshly isolated satellite cells
and, unexpectedly, a sharp decline before the first mitosis,
and subsequently in proliferating, satellite cell-derived
myoblasts. Using genetic tools to conditionally abrogate
canonical Notch signaling during homeostasis, we demonstrate
that satellite cells differentiate spontaneously and
contribute to myofibers, thereby resulting in a severe
depletion of the stem cell pool. Furthermore, whereas loss
of Rbpj function provokes some satellite cells to proliferate
before fusing, strikingly, the majority of mutant cells
terminally differentiate unusually from the quiescent
state, without passing through S-phase. This study establishes
Notch signaling pathway as the first regulator of
cellular quiescence in adult muscle stem cells.
Histone deacetylases (HDACs) play a central role in the epigenetic regulation of gene expression.... more Histone deacetylases (HDACs) play a central role in the epigenetic regulation of gene expression. Aberrant activity of HDACs has been found in several human cancers leading to the development of HDAC inhibitors (HDACi) as anti-tumors drugs. In fact, over the last years, a number of HDACi have been evaluated in clinical trials; these drugs have the common ability to hyperacetylate both histone and non-histone targets, resulting in a variety of effects on both cancer cells and immune responses. Clinical trials of HDACi conducted in solid tumors and hematological malignancies have shown a better clinical efficacy of these drugs in hematological malignancies. In this review, will be highlighted the mechanisms of action underlying the clinical responses obtained with these drugs and the doubts regarding the use of HDACi in cancer therapy.
Annexin A1 (ANXA1) is a calcium- and phospholipid-binding protein involved in a broad range of ce... more Annexin A1 (ANXA1) is a calcium- and phospholipid-binding protein involved in a broad range of cellular events. This study used molecular and microscopy approaches to explore the role of ANXA1 in mouse myoblast C2C12 cell differentiation. We report that ANXA1 expression increases during differentiation and that the down-regulation of ANXA1 significantly inhibits the differentiation process. ANXA1 is expressed in vivo in both quiescent and activated satellite cells and is highly localized in the cells that migrate in the lumen of regenerating fibers after an acute injury. Endogenous ANXA1 co-localizes with actin fibers at the protruding ends of undifferentiated but not differentiated cells suggesting a role of the protein in cell migration. Furthermore, ANXA1 neutralizing antibody reduces MyHC expression, decreases myotube formation and significantly inhibits cell migration. The data reported here suggest for the first time that ANXA1 plays a role in myogenic differentiation.
In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and mainte... more In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and maintenance of stem-like/aggressive features in prostate cancer (PCa) cells comparing zoledronic acid (ZA)-resistant DU145R80 with their parental DU145 cells. ANXA1 is over-expressed in DU145R80 cells and its down-regulation abolishes their resistance to ZA. Moreover, ANXA1 induces DU145 and DU145R80 invasiveness acting through formyl peptide receptors (FPRs). Also, ANXA1 knockdown is able to inhibit epithelial to mesenchymal transition (EMT) and to reduce focal adhesion kinase (FAK) and metalloproteases (MMP)-2/9 expression in PCa cells. DU145R80 show a cancer stem cell (CSC)-like signature with a high expression of CSC markers including CD44, CD133, NANOG, Snail, Oct4 and ALDH7A1 and CSC-related genes as STAT3. Interestingly, ANXA1 knockdown induces these cells to revert from a putative prostate CSC to a more differentiated phenotype resembling DU145 PCa cell signature. Similar results are obtained concerning some drug resistance-related genes such as ATP Binding Cassette G2 (ABCG2) and Lung Resistant Protein (LRP). Our study provides new insights on the role of ANXA1 protein in PCa onset and progression.
Tuberculosis is an increasing threat, owing to the spread of AIDS and to the development of resis... more Tuberculosis is an increasing threat, owing to the spread of AIDS and to the development of resistance of the causative organism, Mycobacterium tuberculosis, to the currently available drugs. Dihydrofolate reductase (DHFR) is an important enzyme of the folate cycle; inhibition of DHFR inhibits growth and causes cell death. The crystal structure of M. tuberculosis DHFR revealed a glycerol tightly bound close to the binding site for the substrate dihydrofolate; this glycerol-binding motif is absent from the human enzyme. A series of pyrimidine-2,4-diamines was designed with a two-carbon tether between a glycerol-mimicking triol and the 6-position of the heterocycle; these compounds also carried aryl substituents at the 5-position. These, their diastereoisomers, analogues lacking two hydroxy groups and analogues lacking the two-carbon spacing linker were synthesised by acylation of the anions derived from phenylacetonitriles with ethyl (4S,5R)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane-4-propanoate, ethyl (4S,5S)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane-4-propanoate, tetrahydrooxepin-2-one and 2,3-O-isopropylidene-d-erythronolactone, respectively, to give the corresponding alpha-acylphenylacetonitriles. Formation of the methyl enol ethers, condensation with guanidine and deprotection gave the pyrimidine-2,4-diamines. Preliminary assay of the abilities of these compounds to inhibit the growth of TB5 Saccharomyces cerevisiae carrying the DHFR genes from M. tuberculosis, human and yeast indicated that 5-phenyl-6-((3R,4S)-3,4,5-trihydroxypentyl)pyrimidine-2,4-diamine selectively inhibited M. tuberculosis DHFR and had little effect on the human or yeast enzymes.
Annexin A1 (ANXA1), a 37 kDa multifunctional protein, is over-expressed in tissues from patients ... more Annexin A1 (ANXA1), a 37 kDa multifunctional protein, is over-expressed in tissues from patients of pancreatic carcinoma (PC) where the protein seems to be associated with malignant transformation and poor prognosis. The expression and localization of ANXA1 in MIA PaCa-2, PANC-1, BxPC-3 and CAPAN-2 cells were detected by Western Blotting and Immunofluorescence assay. Expression and activation of Formyl Peptide Receptors (FPRs) were shown through flow cytometry/PCR and FURA assay, respectively. To investigate the role of ANXA1 in PC cell migration and invasion, we performed in vitro wound-healing and matrigel invasion assays. In all the analyzed PC cell lines, a huge expression and a variable localization of ANXA1 in sub-cellular compartments were observed. We confirmed the less aggressive phenotype of BxPC-3 and CAPAN-2 compared with PANC-1 and MIA PaCa-2 cells, through the evaluation of Epithelial-Mesenchymal Transition (EMT) markers. Then, we tested MIA PaCa-2 and PANC-1 cell migr...
Notch signaling plays a key role in virtually all tissues
and organs in metazoans; however, limi... more Notch signaling plays a key role in virtually all tissues
and organs in metazoans; however, limited examples are
available for the regulatory role of this pathway in adult
quiescent stem cells. We performed a temporal and ontological
assessment of effectors of the Notch pathway that
indicated highest activity in freshly isolated satellite cells
and, unexpectedly, a sharp decline before the first mitosis,
and subsequently in proliferating, satellite cell-derived
myoblasts. Using genetic tools to conditionally abrogate
canonical Notch signaling during homeostasis, we demonstrate
that satellite cells differentiate spontaneously and
contribute to myofibers, thereby resulting in a severe
depletion of the stem cell pool. Furthermore, whereas loss
of Rbpj function provokes some satellite cells to proliferate
before fusing, strikingly, the majority of mutant cells
terminally differentiate unusually from the quiescent
state, without passing through S-phase. This study establishes
Notch signaling pathway as the first regulator of
cellular quiescence in adult muscle stem cells.
Histone deacetylases (HDACs) play a central role in the epigenetic regulation of gene expression.... more Histone deacetylases (HDACs) play a central role in the epigenetic regulation of gene expression. Aberrant activity of HDACs has been found in several human cancers leading to the development of HDAC inhibitors (HDACi) as anti-tumors drugs. In fact, over the last years, a number of HDACi have been evaluated in clinical trials; these drugs have the common ability to hyperacetylate both histone and non-histone targets, resulting in a variety of effects on both cancer cells and immune responses. Clinical trials of HDACi conducted in solid tumors and hematological malignancies have shown a better clinical efficacy of these drugs in hematological malignancies. In this review, will be highlighted the mechanisms of action underlying the clinical responses obtained with these drugs and the doubts regarding the use of HDACi in cancer therapy.
Annexin A1 (ANXA1) is a calcium- and phospholipid-binding protein involved in a broad range of ce... more Annexin A1 (ANXA1) is a calcium- and phospholipid-binding protein involved in a broad range of cellular events. This study used molecular and microscopy approaches to explore the role of ANXA1 in mouse myoblast C2C12 cell differentiation. We report that ANXA1 expression increases during differentiation and that the down-regulation of ANXA1 significantly inhibits the differentiation process. ANXA1 is expressed in vivo in both quiescent and activated satellite cells and is highly localized in the cells that migrate in the lumen of regenerating fibers after an acute injury. Endogenous ANXA1 co-localizes with actin fibers at the protruding ends of undifferentiated but not differentiated cells suggesting a role of the protein in cell migration. Furthermore, ANXA1 neutralizing antibody reduces MyHC expression, decreases myotube formation and significantly inhibits cell migration. The data reported here suggest for the first time that ANXA1 plays a role in myogenic differentiation.
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Papers by Valentina Bizzarro
and organs in metazoans; however, limited examples are
available for the regulatory role of this pathway in adult
quiescent stem cells. We performed a temporal and ontological
assessment of effectors of the Notch pathway that
indicated highest activity in freshly isolated satellite cells
and, unexpectedly, a sharp decline before the first mitosis,
and subsequently in proliferating, satellite cell-derived
myoblasts. Using genetic tools to conditionally abrogate
canonical Notch signaling during homeostasis, we demonstrate
that satellite cells differentiate spontaneously and
contribute to myofibers, thereby resulting in a severe
depletion of the stem cell pool. Furthermore, whereas loss
of Rbpj function provokes some satellite cells to proliferate
before fusing, strikingly, the majority of mutant cells
terminally differentiate unusually from the quiescent
state, without passing through S-phase. This study establishes
Notch signaling pathway as the first regulator of
cellular quiescence in adult muscle stem cells.
activity of HDACs has been found in several human cancers leading to the development of HDAC inhibitors (HDACi) as
anti-tumors drugs. In fact, over the last years, a number of HDACi have been evaluated in clinical trials; these drugs have
the common ability to hyperacetylate both histone and non-histone targets, resulting in a variety of effects on both cancer
cells and immune responses. Clinical trials of HDACi conducted in solid tumors and hematological malignancies have
shown a better clinical efficacy of these drugs in hematological malignancies. In this review, will be highlighted the
mechanisms of action underlying the clinical responses obtained with these drugs and the doubts regarding the use of
HDACi in cancer therapy.
and organs in metazoans; however, limited examples are
available for the regulatory role of this pathway in adult
quiescent stem cells. We performed a temporal and ontological
assessment of effectors of the Notch pathway that
indicated highest activity in freshly isolated satellite cells
and, unexpectedly, a sharp decline before the first mitosis,
and subsequently in proliferating, satellite cell-derived
myoblasts. Using genetic tools to conditionally abrogate
canonical Notch signaling during homeostasis, we demonstrate
that satellite cells differentiate spontaneously and
contribute to myofibers, thereby resulting in a severe
depletion of the stem cell pool. Furthermore, whereas loss
of Rbpj function provokes some satellite cells to proliferate
before fusing, strikingly, the majority of mutant cells
terminally differentiate unusually from the quiescent
state, without passing through S-phase. This study establishes
Notch signaling pathway as the first regulator of
cellular quiescence in adult muscle stem cells.
activity of HDACs has been found in several human cancers leading to the development of HDAC inhibitors (HDACi) as
anti-tumors drugs. In fact, over the last years, a number of HDACi have been evaluated in clinical trials; these drugs have
the common ability to hyperacetylate both histone and non-histone targets, resulting in a variety of effects on both cancer
cells and immune responses. Clinical trials of HDACi conducted in solid tumors and hematological malignancies have
shown a better clinical efficacy of these drugs in hematological malignancies. In this review, will be highlighted the
mechanisms of action underlying the clinical responses obtained with these drugs and the doubts regarding the use of
HDACi in cancer therapy.