Publications by authors named "Francesco Sola"

21 Publications

  • Page 1 of 1

Discovery of 2-[1-(4,4-Difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide (NMS-P118): A Potent, Orally Available, and Highly Selective PARP-1 Inhibitor for Cancer Therapy.

J Med Chem 2015 Sep 26;58(17):6875-98. Epub 2015 Aug 26.

Oncology, Nerviano Medical Sciences Srl , Viale Pasteur 10, 20014 Nerviano, Milan, Italy.

The nuclear protein poly(ADP-ribose) polymerase-1 (PARP-1) has a well-established role in the signaling and repair of DNA and is a prominent target in oncology, as testified by the number of candidates in clinical testing that unselectively target both PARP-1 and its closest isoform PARP-2. The goal of our program was to find a PARP-1 selective inhibitor that would potentially mitigate toxicities arising from cross-inhibition of PARP-2. Thus, an HTS campaign on the proprietary Nerviano Medical Sciences (NMS) chemical collection, followed by SAR optimization, allowed us to discover 2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide (NMS-P118, 20by). NMS-P118 proved to be a potent, orally available, and highly selective PARP-1 inhibitor endowed with excellent ADME and pharmacokinetic profiles and high efficacy in vivo both as a single agent and in combination with Temozolomide in MDA-MB-436 and Capan-1 xenograft models, respectively. Cocrystal structures of 20by with both PARP-1 and PARP-2 catalytic domain proteins allowed rationalization of the observed selectivity.
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http://dx.doi.org/10.1021/acs.jmedchem.5b00680DOI Listing
September 2015

Synthesis and biological evaluation of RGD peptidomimetic-paclitaxel conjugates bearing lysosomally cleavable linkers.

Chemistry 2015 Apr 17;21(18):6921-9. Epub 2015 Mar 17.

Università degli Studi di Milano, Dipartimento di Chimica, Via C. Golgi, 19, 20133, Milan (Italy), Fax: (+39) 02-5031-4072.

Two small-molecule-drug conjugates (SMDCs, 6 and 7) featuring lysosomally cleavable linkers (namely the Val-Ala and Phe-Lys peptide sequences) were synthesized by conjugation of the αvβ3-integrin ligand cyclo[DKP-RGD]-CH2NH2 (2) to the anticancer drug paclitaxel (PTX). A third cyclo[DKP-RGD]-PTX conjugate with a nonpeptide "uncleavable" linker (8) was also synthesized to be tested as a negative control. These three SMDCs were able to inhibit biotinylated vitronectin binding to the purified αVβ3-integrin receptor at nanomolar concentrations and showed good stability at pH 7.4 and pH 5.5. Cleavage of the two peptide linkers was observed in the presence of lysosomal enzymes, whereas conjugate 8, which possesses a nonpeptide "uncleavable" linker, remained intact under these conditions. The antiproliferative activities of the conjugates were evaluated against two isogenic cell lines expressing the integrin receptor at different levels: the acute lymphoblastic leukemia cell line CCRF-CEM (αVβ3-) and its subclone CCRF-CEM αVβ3 (αVβ3+). Fairly effective integrin targeting was displayed by the cyclo[DKP-RGD]-Val-Ala-PTX conjugate (6), which was found to differentially inhibit proliferation in antigen-positive CCRF-CEM αVβ3 versus antigen-negative isogenic CCRF-CEM cells. The total lack of activity displayed by the "uncleavable" cyclo[DKP-RGD]-PTX conjugate (8) clearly demonstrates the importance of the peptide linker for achieving the selective release of the cytotoxic payload.
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http://dx.doi.org/10.1002/chem.201500158DOI Listing
April 2015

Fragment-based hit discovery and structure-based optimization of aminotriazoloquinazolines as novel Hsp90 inhibitors.

Bioorg Med Chem 2014 Aug 14;22(15):4135-50. Epub 2014 Jun 14.

Oncology, Nerviano Medical Sciences, Viale Pasteur 10, 20014 Nerviano (MI), Italy. Electronic address:

In the last decade the heat shock protein 90 (Hsp90) has emerged as a major therapeutic target and many efforts have been dedicated to the discovery of Hsp90 inhibitors as new potent anticancer agents. Here we report the identification of a novel class of Hsp90 inhibitors by means of a biophysical FAXS-NMR based screening of a library of fragments. The use of X-ray structure information combined with modeling studies enabled the fragment evolution of the initial triazoloquinazoline hit to a class of compounds with nanomolar potency and drug-like properties suited for further lead optimization.
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http://dx.doi.org/10.1016/j.bmc.2014.05.056DOI Listing
August 2014

Discovery of NMS-E973 as novel, selective and potent inhibitor of heat shock protein 90 (Hsp90).

Bioorg Med Chem 2013 Nov 19;21(22):7047-63. Epub 2013 Sep 19.

Nerviano Medical Sciences S.r.l., Oncology, Viale Pasteur 10, 20014 Nerviano, MI, Italy. Electronic address:

Novel small molecule inhibitors of heat shock protein 90 (Hsp90) were discovered with the help of a fragment based drug discovery approach (FBDD) and subsequent optimization with a combination of structure guided design, parallel synthesis and application of medicinal chemistry principles. These efforts led to the identification of compound 18 (NMS-E973), which displayed significant efficacy in a human ovarian A2780 xenograft tumor model, with a mechanism of action confirmed in vivo by typical modulation of known Hsp90 client proteins, and with a favorable pharmacokinetic and safety profile.
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http://dx.doi.org/10.1016/j.bmc.2013.09.018DOI Listing
November 2013

9-Fluorenone-2-Carboxylic Acid as a Scaffold for Tubulin Interacting Compounds.

Chempluschem 2013 Jul 13;78(7):663-669. Epub 2013 May 13.

Dipartimento di Chimica-INSTM-UdR, and Istituto di Scienze e tecnologie molecolari del CNR (CNR-ISTM), Università degli Studi di Milano, Via Golgi 19, 20133 Milano (Italy).

The introduction of a hydrophobic group at position 7 of 9-fluorenone-2-carboxylic acid generates new tubulin binders, the design of which is suggested by modeling studies. The synthesis is based on the use of 2,7-dibromo-fluorenone as starting material. The antiproliferative activity on two different cell lines, fluorescent microscopy, flow cytometry, and sedimentation assay tests confirmed the supposed mechanism.
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http://dx.doi.org/10.1002/cplu.201300036DOI Listing
July 2013

NMS-E973, a novel synthetic inhibitor of Hsp90 with activity against multiple models of drug resistance to targeted agents, including intracranial metastases.

Clin Cancer Res 2013 Jul 14;19(13):3520-32. Epub 2013 May 14.

Department of Biotechnology, Nerviano Medical Sciences Srl, Nerviano (MI), Italy.

Purpose: Recent developments of second generation Hsp90 inhibitors suggested a potential for development of this class of molecules also in tumors that have become resistant to molecular targeted agents. Disease progression is often due to brain metastases, sometimes related to insufficient drug concentrations within the brain. Our objective was to identify and characterize a novel inhibitor of Hsp90 able to cross the blood-brain barrier (BBB).

Experimental Design: Here is described a detailed biochemical and crystallographic characterization of NMS-E973. Mechanism-based anticancer activity was described in cell models, including models of resistance to kinase inhibitors. Pharmacokinetics properties were followed in plasma, tumor, liver, and brain. In vivo activity and pharmacodynamics, as well as the pharmacokinetic/pharmacodynamic relationships, were evaluated in xenografts, including an intracranially implanted melanoma model.

Results: NMS-E973, representative of a novel isoxazole-derived class of Hsp90 inhibitors, binds Hsp90α with subnanomolar affinity and high selectivity towards kinases, as well as other ATPases. It possesses potent antiproliferative activity against tumor cell lines and a favorable pharmacokinetic profile, with selective retention in tumor tissue and ability to cross the BBB. NMS-E973 induces tumor shrinkage in different human tumor xenografts, and is highly active in models of resistance to kinase inhibitors. Moreover, consistent with its brain penetration, NMS-E973 is active also in an intracranially implanted melanoma model.

Conclusions: Overall, the efficacy profile of NMS-E973 suggests a potential for development in different clinical settings, including tumors that have become resistant to molecular targeted agents, particularly in cases of tumors which reside beyond the BBB.
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http://dx.doi.org/10.1158/1078-0432.CCR-12-3512DOI Listing
July 2013

NMS-P937, an orally available, specific small-molecule polo-like kinase 1 inhibitor with antitumor activity in solid and hematologic malignancies.

Mol Cancer Ther 2012 Apr 7;11(4):1006-16. Epub 2012 Feb 7.

Nerviano Medical Sciences Srl, Nerviano, Milan, Italy.

Polo-like kinase 1 (PLK1) is a serine/threonine protein kinase considered to be the master player of cell-cycle regulation during mitosis. It is indeed involved in centrosome maturation, bipolar spindle formation, chromosome separation, and cytokinesis. PLK1 is overexpressed in a variety of human tumors and its overexpression often correlates with poor prognosis. Although five different PLKs are described in humans, depletion or inhibition of kinase activity of PLK1 is sufficient to induce cell-cycle arrest and apoptosis in cancer cell lines and in xenograft tumor models. NMS-P937 is a novel, orally available PLK1-specific inhibitor. The compound shows high potency in proliferation assays having low nanomolar activity on a large number of cell lines, both from solid and hematologic tumors. NMS-P937 potently causes a mitotic cell-cycle arrest followed by apoptosis in cancer cell lines and inhibits xenograft tumor growth with clear PLK1-related mechanism of action at well-tolerated doses in mice after oral administration. In addition, NMS-P937 shows potential for combination in clinical settings with approved cytotoxic drugs, causing tumor regression in HT29 human colon adenocarcinoma xenografts upon combination with irinotecan and prolonged survival of animals in a disseminated model of acute myelogenous leukemia in combination with cytarabine. NMS-P937, with its favorable pharmacologic parameters, good oral bioavailability in rodent and nonrodent species, and proven antitumor activity in different preclinical models using a variety of dosing regimens, potentially provides a high degree of flexibility in dosing schedules and warrants investigation in clinical settings.
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http://dx.doi.org/10.1158/1535-7163.MCT-11-0765DOI Listing
April 2012

Phosphorylation of TCTP as a marker for polo-like kinase-1 activity in vivo.

Anticancer Res 2010 Dec;30(12):4973-85

BU Oncology, Nerviano Medical Sciences srl, 20014 Nerviano, Italy.

Polo-like kinase 1 (PLK1) is the master regulator of mitosis and a target for anticancer therapy. To develop a marker of PLK1 activity in cells and tumour tissues, this study focused on translational controlled tumour protein (TCTP) and identified serine 46 as a site phosphorylated by PLK1 in vitro. Using an antibody raised against phospho-TCTP-Ser46, it was demonstrated that phosphorylation at this site correlates with PLK1 level and kinase activity in cells. Moreover, PLK1 depletion by siRNA or inactivation by specific inhibitors caused a correspondent decrease in phospho-TCTP-Ser46 signal validating this site as a direct marker of PLK1. Using this marker, the study characterized PLK1 inhibitors in cells by setting up a high-content assay and finally immunohistochemical assay suitable for following inhibitor activity in preclinical tumour models and possibly in clinical studies was developed.
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December 2010

Targeting the mitotic checkpoint for cancer therapy with NMS-P715, an inhibitor of MPS1 kinase.

Cancer Res 2010 Dec;70(24):10255-64

Department of Cell Biology-Oncology, Nerviano Medical Sciences, Viale Pasteur 10, Nerviano 20014, Italy.

MPS1 kinase is a key regulator of the spindle assembly checkpoint (SAC), a mitotic mechanism specifically required for proper chromosomal alignment and segregation. It has been found aberrantly overexpressed in a wide range of human tumors and is necessary for tumoral cell proliferation. Here we report the identification and characterization of NMS-P715, a selective and orally bioavailable MPS1 small-molecule inhibitor, which selectively reduces cancer cell proliferation, leaving normal cells almost unaffected. NMS-P715 accelerates mitosis and affects kinetochore components localization causing massive aneuploidy and cell death in a variety of tumoral cell lines and inhibits tumor growth in preclinical cancer models. Inhibiting the SAC could represent a promising new approach to selectively target cancer cells.
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http://dx.doi.org/10.1158/0008-5472.CAN-10-2101DOI Listing
December 2010

4,5-Dihydro-1H-pyrazolo[4,3-h]quinazolines as potent and selective Polo-like kinase 1 (PLK1) inhibitors.

Bioorg Med Chem Lett 2010 Nov 17;20(22):6489-94. Epub 2010 Sep 17.

Nerviano Medical Sciences srl, Business Unit Oncology, Viale Pasteur 10, 20014 Nerviano, Milan, Italy.

A series of 4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline derivatives was optimized as Polo-like kinase 1 inhibitors. Extensive SAR afforded a highly potent and selective PLK1 compound. The compound showed good antiproliferative activity when tested in a panel of tumor cell lines with PLK1 related mechanism of action and with good in vivo antitumor efficacy in two xenograft models after i.v. administration.
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http://dx.doi.org/10.1016/j.bmcl.2010.09.060DOI Listing
November 2010

Cell division cycle 7 kinase inhibitors: 1H-pyrrolo[2,3-b]pyridines, synthesis and structure-activity relationships.

J Med Chem 2009 Jul;52(14):4380-90

Nerviano Medical Sciences, 20014 Nerviano, Milano, Italy.

Cdc7 kinase has recently emerged as an attractive target for cancer therapy and low-molecular-weight inhibitors of Cdc7 kinase have been found to be effective in the inhibition of tumor growth in animal models. In this paper, we describe synthesis and structure-activity relationships of new 1H-pyrrolo[2,3-b]pyridine derivatives identified as inhibitors of Cdc7 kinase. Progress from (Z)-2-phenyl-5-(1H-pyrrolo[2,3-b]pyridin-3-ylmethylene)-3,5-dihydro-4H-imidazol-4-one (1) to [(Z)-2-(benzylamino)-5-(1H-pyrrolo[2,3-b]pyridin-3-ylmethylene)-1,3-thiazol-4(5H)-one] (42), a potent ATP mimetic inhibitor of Cdc7 kinase with IC(50) value of 7 nM, is also reported.
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http://dx.doi.org/10.1021/jm900248gDOI Listing
July 2009

High-content analysis of kinase activity in cells.

Comb Chem High Throughput Screen 2008 Aug;11(7):523-36

Department of Cell Biology, Oncology Business Unit, Nerviano Medical Sciences Srl, Nerviano, Milano, Italy.

High-content analysis (HCA) is a term used to describe techniques involving multiplexed analysis of fluorescent markers to measure multiple cellular responses to biological stimuli or drug treatment. HCA is usually based on automated microscopy or related technologies, and its value lies in providing multiparametric information on single cells within a population. During the last decade, several HCA approaches have been developed and applied to assess cellular mechanism of action of pharmacologically relevant compounds identified through biochemical screening or similar in vitro methods. With automation and instrument development, these approaches have evolved to the extent that the technique is now routinely used in screening applications, including primary HTS on compound collections. Here, we review the field and discuss in particular the application of HCA to the discovery of small molecule inhibitors targeting kinases which are implicated in Oncology.
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http://dx.doi.org/10.2174/138620708785204126DOI Listing
August 2008

A Cdc7 kinase inhibitor restricts initiation of DNA replication and has antitumor activity.

Nat Chem Biol 2008 Jun 11;4(6):357-65. Epub 2008 May 11.

Nerviano Medical Sciences Oncology, Via Pasteur 10, 20014 Nerviano, Italy.

Cdc7 is an essential kinase that promotes DNA replication by activating origins of replication. Here, we characterized the potent Cdc7 inhibitor PHA-767491 (1) in biochemical and cell-based assays, and we tested its antitumor activity in rodents. We found that the compound blocks DNA synthesis and affects the phosphorylation of the replicative DNA helicase at Cdc7-dependent phosphorylation sites. Unlike current DNA synthesis inhibitors, PHA-767491 prevents the activation of replication origins but does not impede replication fork progression, and it does not trigger a sustained DNA damage response. Treatment with PHA-767491 results in apoptotic cell death in multiple cancer cell types and tumor growth inhibition in preclinical cancer models. To our knowledge, PHA-767491 is the first molecule that directly affects the mechanisms controlling initiation as opposed to elongation in DNA replication, and its activities suggest that Cdc7 kinase inhibition could be a new strategy for the development of anticancer therapeutics.
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http://dx.doi.org/10.1038/nchembio.90DOI Listing
June 2008

Loss of huntingtin function complemented by small molecules acting as repressor element 1/neuron restrictive silencer element silencer modulators.

J Biol Chem 2007 Aug 12;282(34):24554-62. Epub 2007 Jun 12.

Centre for Stem Cell Research and Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, Milan 20133, Italy.

Increased levels of the repressor element 1/neuron restrictive silencer element (RE1/NRSE) silencing activity promoter, and a consequent reduction in the transcription of many RE1/NRSE-bearing neuronal genes, including brain-derived neurotrophic factor (BDNF), have been demonstrated in Huntington disease (HD) and represent one possible effector of its selective neuronal vulnerability. Restoring the expression levels of neuronal genes in diseased neurons therefore seems to be an attractive therapeutic approach. To this end, we have developed a cell-based reporter assay for monitoring RE1/NRSE silencing activity and validated it by genetically inactivating the RE1/NRSE or pharmacologically stimulating global transcription. In a pilot compound screen, we identified three closely related structural analogues that up-regulate reporter expression at low nanomolar concentrations, and follow-up studies have shown that they efficaciously increase endogenous BDNF levels in HD cells. Moreover, one of the compounds increases the viability of HD cells. Our findings suggest a new avenue for the development of drugs for HD and other neurodegenerative disorders based on the pharmacological up-regulation of the production of the neuronal survival factor BDNF and of other RE1/NRSE-regulated neuronal genes.
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http://dx.doi.org/10.1074/jbc.M609885200DOI Listing
August 2007

PHA-680632, a novel Aurora kinase inhibitor with potent antitumoral activity.

Clin Cancer Res 2006 Jul;12(13):4080-9

Nerviano Medical Sciences S.r.l.-Oncology, Milan, Italy.

Purpose: Aurora kinases play critical roles during mitosis in chromosome segregation and cell division. The aim of this study was to determine the preclinical profile of a novel, highly selective Aurora kinase inhibitor, PHA-680632, as a candidate for anticancer therapy.

Experimental Design: The activity of PHA-680632 was assayed in a biochemical ATP competitive kinase assay. A wide panel of cell lines was evaluated for antiproliferative activity. Cell cycle analysis. Immunohistochemistry, Western blotting, and Array Scan were used to follow mechanism of action and biomarker modulation. Specific knockdown of the targets by small interfering RNA was followed to validate the observed phenotypes. Efficacy was determined in different xenograft models and in a transgenic animal model of breast cancer.

Results: PHA-680632 is active on a wide range of cancer cell lines and shows significant tumor growth inhibition in different animal tumor models at well-tolerated doses. The mechanism of action of PHA-680632 is in agreement with inhibition of Aurora kinases. Histone H3 phosphorylation in Ser10 is mediated by Aurora B kinase, and our kinetic studies on its inhibition by PHA-680632 in vitro and in vivo show that phosphorylation of histone H3 is a good biomarker to follow activity of PHA-680632.

Conclusions: PHA-680632 is the first representative of a new class of Aurora inhibitors with a high potential for further development as an anticancer therapeutic. On treatment, different cell lines respond differentially, suggesting the absence of critical cell cycle checkpoints that could be the basis for a favorable therapeutic window.
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http://dx.doi.org/10.1158/1078-0432.CCR-05-1964DOI Listing
July 2006

Quantification of the proliferation index of human dermal fibroblast cultures with the ArrayScan high-content screening reader.

Drug Discov Today 2005 ;Suppl:31-42

DRO-Oncology, Pharmacology Department, Pharmacia Corporation, Nerviano, Italy.

High-throughput cell-based assays are becoming a powerful approach in the drug discovery process. The ArrayScan high-content screening (HCS) reader is a cytometer based on a fully automated fluorescence microscope that is able to obtain quantitative information on the intensity and localization of fluorescence signals within single cells over a wide cell population. The aim of this work was to set up an automated HCS multiparameter analysis for the quantification of the in vitro proliferation index of normal human dermal fibroblast (NHDF) cultures. The authors stimulated starved NHDF with insulin-like growth factor-1, platelet-derived growth factor, epidermal growth factor, fibroblast growth factor, or serum, and they quantified the proliferation index by measuring the expression of Ki-67 antigen, the incorporation of bromodeoxyuridine (BrdU), and the phosphorylation of the retinoblastoma protein (pRb). This approach also allowed quantification of the mitotic index by phospho-histone H3 staining and the percentage of cells in the S-phase by BrdU incorporation. The proliferation data from the ArrayScan assays were validated by comparison with a reference enzyme-linked immunosorbent assay (ELISA) and by flow cytometry. The measured proliferation indices were highly reproducible in repeated measures and independent experiments. The authors therefore propose that the ArrayScan HCS system could be used for high-throughput multiparameter analysis and quantification of the proliferation of cellular cultures.
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June 2013

Cdc7 inhibition reveals a p53-dependent replication checkpoint that is defective in cancer cells.

Cancer Res 2004 Oct;64(19):7110-6

Department of Biology, Nerviano Medical Science, Nerviano, Italy.

Cdc7 is an evolutionarily conserved kinase that regulates S phase by promoting replication origin activation. Down-regulation of Cdc7 by small interfering RNA in a variety of tumor cell lines causes an abortive S phase, leading to cell death by either p53-independent apoptosis or aberrant mitosis. Unlike replication fork blockade, Cdc7-depleted tumor cells do not elicit a robust checkpoint response; thus, inhibitory signals preventing additional cell cycle progression are not generated. In normal fibroblasts, however, a p53-dependent pathway actively prevents progression through a lethal S phase in the absence of sufficient Cdc7 kinase. We show that in this experimental system, p53 is required for the lasting maintenance of this checkpoint and for cell viability. With this work we reveal and begin to characterize a novel mechanism that regulates DNA synthesis in human cells, and we suggest that inhibition of Cdc7 kinase represents a promising approach for the development of a new generation of anticancer agents.
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http://dx.doi.org/10.1158/0008-5472.CAN-04-1547DOI Listing
October 2004

The death domain protein p84N5, but not the short isoform p84N5s, is cell cycle-regulated and shuttles between the nucleus and the cytoplasm.

FEBS Lett 2004 Sep;574(1-3):13-9

Department of Biology, Nerviano Medical Science, 20014 Nerviano, Italy.

P84N5 is a death domain containing protein that interacts with the tumor suppressor retinoblastoma protein and induces apoptosis. We cloned and characterized two novel alternatively spliced versions of p84N5. The p84N5 short isoform (p84N5s) lacks the death domain and does not induce apoptosis. We showed that p84N5, but not p84N5s, is cell cycle regulated. We found that p84N5-GFP chimera can rapidly shuttle between the nucleus and the cytoplasm. Taken together, these observations suggest that p84N5 may transmit signals from the nucleus to cytoplasmic effectors.
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http://dx.doi.org/10.1016/j.febslet.2004.07.074DOI Listing
September 2004

Quantification of the proliferation index of human dermal fibroblast cultures with the ArrayScan high-content screening reader.

J Biomol Screen 2004 Apr;9(3):232-43

DRO-Oncology, Pharmacology Department, Pharmacia Corporation, Nerviano, Italy.

High-throughput cell-based assays are becoming a powerful approach in the drug discovery process. The ArrayScan high-content screening (HCS) reader is a cytometer based on a fully automated fluorescence microscope that is able to obtain quantitative information on the intensity and localization of fluorescence signals within single cells over a wide cell population. The aim of this work was to set up an automated HCS multiparameter analysis for the quantification of the in vitro proliferation index of normal human dermal fibroblast (NHDF) cultures. The authors stimulated starved NHDF with insulin-like growth factor-1, platelet-derived growth factor, epidermal growth factor, fibroblast growth factor, or serum, and they quantified the proliferation index by measuring the expression of Ki-67 antigen, the incorporation of bromodeoxyuridine (BrdU), and the phosphorylation of the retinoblastoma protein (pRb). This approach also allowed quantification of the mitotic index by phospho-histone H3 staining and the percentage of cells in the S-phase by BrdU incorporation. The proliferation data from the ArrayScan assays were validated by comparison with a reference enzyme-linked immunosorbent assay (ELISA) and by flow cytometry. The measured proliferation indices were highly reproducible in repeated measures and independent experiments. The authors therefore propose that the ArrayScan HCS system could be used for high-throughput multiparameter analysis and quantification of the proliferation of cellular cultures.
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http://dx.doi.org/10.1177/1087057103262836DOI Listing
April 2004

Essential role of human CDT1 in DNA replication and chromatin licensing.

J Cell Sci 2002 Apr;115(Pt 7):1435-40

DRO-Oncology, Pharmacology Department, Pharmacia Corp., Via Pasteur 10, 20014 Nerviano, Italy.

Formation of pre-replicative complexes at origins is an early cell cycle event essential for DNA duplication. A large body of evidence supports the notion that Cdc6 protein, through its interaction with the origin recognition complex, is required for pre-replicative complex assembly by loading minichromosome maintenance proteins onto DNA. In fission yeast and Xenopus, this reaction known as the licensing of chromatin for DNA replication also requires the newly identified Cdt1 protein. We studied the role of hCdt1 protein in the duplication of the human genome by antibody microinjection experiments and analyzed its expression during the cell cycle in human non-transformed cells. We show that hCdt1 is essential for DNA replication in intact human cells, that it executes its function in a window of the cell cycle overlapping with pre-replicative complex formation and that it is necessary for the loading of minichromosome maintenance proteins onto chromatin. Intriguingly, we observed that hCdt1 protein, in contrast to other licensing factors, is already present in serum-deprived G0 arrested cells and its levels increase only marginally upon re-entry in the cell cycle.
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April 2002

Endothelial cells overexpressing basic fibroblast growth factor (FGF-2) induce vascular tumors in immunodeficient mice.

Angiogenesis 1997 ;1(1):102-116

Pharmacia-Upjohn, Nerviano, 20014 Milan, Italy.

Basic fibroblast growth factor (FGF-2) is expressed in vascular endothelium during tumor neovascularization and angioproliferative diseases, including vascular tumors and Kaposi's sarcoma (KS). We have investigated the in vivo biological consequences of endothelial cell activation by endogenous FGF-2 in a mouse aortic endothelial cell line transfected with a retroviral expression vector harboring a human FGF-2 cDNA and the neomycin resistance gene. FGF-2 transfectants, named pZipbFGF2-MAE cells, caused the rapid growth of highly vascularized, non-infiltrating tumors when injected in nude mice. In contrast, lesions grew poorly when cells were injected in immunocompetent syngeneic animals. Histologically, the tumors had the appearance of hemangioendothelioma with spindled areas resembling KS and with numerous CD31+ blood vessels and lacunae. Southern blot analysis of tumor DNA, as well as disaggregation of the lesion followed by in vitro cell culture, revealed that less than 10% of the cells in the tumor mass retain FGF-2 overexpression and neomycin resistance at 6-8 weeks post-injection. Nevertheless, in vitro G418 selection allowed the isolation from the tumor of a FGF-2-overexpressing cell population showing biochemical and biological characteristics similar to those of pZipbFGF2-MAE cells, including the capacity to originate vascular lesions when re-injected in nude mice. To evaluate the effect of angiostatic compounds on the growth and vascularization of pZipbFGF2-MAE cell-induced lesions, nude mice were treated weekly (100mg/kg, i.p.) with the angiostatic sulfonated distamycin A derivative 2,2'-(carbonyl-bis-[imino-N-methyl-4,2-pyrrole carbonyl-imino-{N-methyl-4,2-pyrrole}carbonylimino])-bis-(1,5-naphthalene) disulfonic acid (PNU 153429). The results demonstrate that PNU 153429 inhibits the growth of the lesions and causes a approximately 50% decrease in CD31+ microvessel density. In conclusion, the data indicate that FGF-2-overexpressing endothelial cells cause vascular lesions in immunodeficient mice which may represent a novel model for opportunistic vascular tumors suitable for the evaluation of angiostatic compounds.
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http://dx.doi.org/10.1023/A:1018309200629DOI Listing
January 1997