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2.
Int J Biochem Cell Biol ; 40(5): 848-54, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17543573

RESUMO

The early hematopoietic zinc finger protein/zinc finger protein 521 (EHZF/ZNF521) is a recently identified, 1131 amino-acid-long nuclear factor that contains 30 zinc fingers distributed in clusters throughout its sequence. A 13-AA motif, that binds to components of the nuclear remodelling and histone deacetylation (NuRD) complex and is conserved in several trascriptional co-repressors, is located at the amino-terminal end of the molecule. EHZF/ZNF521 expression is high in the most immature cells of the haematopoietic system and declines with differentiation. Its transcript is also abundant in brain, particularly in the cerebellum. Its murine counterpart, Evi3/Zfp521, is enriched in haematopoietic and neural stem cells, in cerebellar granule neuron precursors and in the developing striatum. Enforced expression of EHZF/ZNF521 in haematopoietic progenitors results in their expansion and in inhibition of differentiation. EHZF/ZNF521 is a member of the BMP signalling pathway and an inhibitor of the transcription factor OLF1/EBF1, implicated in the differentiation of neural progenitors and in the specification of the B-cell lineage. EHZF expression is observed in most acute myelogenous leukaemias and is particularly high in those with rearrangements of the MLL gene, where EHZF may contribute to the leukaemic phenotype. EHZF/ZNF521 is also abundant in medulloblastomas and other brain tumours. Taken together, the data available suggest a possible role for this factor in development, stem cell regulation and oncogenesis.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Células-Tronco/metabolismo , Animais , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Humanos , Camundongos , Neoplasias/etiologia , Dedos de Zinco
3.
Int J Biochem Cell Biol ; 40(10): 2110-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18372207

RESUMO

The tumor suppressor protein p53 triggers many of the cellular responses to DNA damage by regulating the transcription of a series of downstream target genes. p53 acts on the promoter of the target genes by interacting with the trimeric transcription factor NF-Y. H ferritin promoter activity is tightly dependent on a multiprotein complex called Bbf; on this complex NF-Y plays a major role. The aim of this work was to study the modulation of H ferritin expression levels by p53. CAT reporter assays indicate that: (i) p53 overexpression strongly downregulates the transcriptional efficiency driven by an H ferritin promoter construct containing only the NF-Y recognition sequence and that the phenomenon is reverted by p53 siRNA; (ii) the p53 C-terminal region is sufficient to elicitate this regulation and that a correct C-terminal acetylation is also required. The H ferritin promoter displays no p53-binding sites; chromatin immunoprecipitation assays indicate that p53 is recruited on this promoter by NF-Y. The p53-NF-Y interaction does not alter the NF-Y DNA-binding ability as indicated by electrophoretic mobility shift assay (EMSA) analysis. These results demonstrate that the gene coding for the H ferritin protein belongs to the family of p53-regulated genes, therefore adding a new level of complexity to the regulation of the H ferritin transcription and delineate a role for this protein in a series of cellular events triggered by p53 activation.


Assuntos
Apoferritinas/genética , Fator de Ligação a CCAAT/metabolismo , Regulação para Baixo/genética , Regiões Promotoras Genéticas/genética , Transcrição Gênica , Proteína Supressora de Tumor p53/metabolismo , Imunoprecipitação da Cromatina , Regulação para Baixo/efeitos dos fármacos , Doxorrubicina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Células HeLa , Humanos , Ligação Proteica/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/química , Fatores de Transcrição de p300-CBP/metabolismo
4.
Clin Cancer Res ; 13(19): 5903-9, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17908986

RESUMO

PURPOSE: B-cell-activating factor (BAFF) is a tumor necrosis factor superfamily member critical for the maintenance and homeostasis of normal B-cell development. It has been implicated in conferring a survival advantage to B-cell malignancies, including multiple myeloma (MM). EXPERIMENTAL DESIGN: Here, we validate the role of BAFF in the in vivo pathogenesis of MM examining BAFF and its receptors in the context of patient MM cells and show activity of anti-BAFF antibody in a severe combined immunodeficient model of human MM. RESULTS: Gene microarrays and flow cytometry studies showed increased transcripts and the presence of all three receptors for BAFF in CD138+ patient MM cells, as well as an increase in plasma BAFF levels in 51 MM patients. Functional studies show that recombinant BAFF protects MM cells against dexamethasone-induced apoptosis accompanied by an increase in survival proteins belonging to the BCL family. These in vitro studies led to the evaluation of a clinical grade-neutralizing antibody to BAFF in a severe combined immunodeficient human MM model. Anti-BAFF-treated animals showed decreased soluble human interleukin 6 receptor levels, a surrogate marker of viable tumor, suggesting direct anti-MM activity. This translated into a survival advantage of 16 days (P < 0.05), a decrease in tartrate-resistant acid phosphatase-positive osteoclasts, and a reduction in radiologically evident lytic lesions in anti-BAFF-treated animals. CONCLUSIONS: Our data show a role for BAFF as a survival factor in MM. Importantly, the in vivo antitumor activity of neutralizing anti-BAFF antibody provide the preclinical rationale for its evaluation in the treatment of MM.


Assuntos
Anticorpos/química , Fator Ativador de Células B/fisiologia , Mieloma Múltiplo/genética , Mieloma Múltiplo/imunologia , Osteoclastos/metabolismo , Fosfatase Ácida/metabolismo , Animais , Fator Ativador de Células B/imunologia , Linhagem Celular Tumoral , Sobrevivência Celular , Perfilação da Expressão Gênica , Humanos , Interleucina-6/metabolismo , Isoenzimas/metabolismo , Camundongos , Camundongos SCID , Proteínas Recombinantes/química , Fosfatase Ácida Resistente a Tartarato , Resultado do Tratamento
5.
J Mol Med (Berl) ; 85(7): 707-21, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17571248

RESUMO

The interleukin-2 is a cytokine that is essential for lymphocytic survival and function. Ectopic expression of the IL-2 receptor in epithelial tissues has been reported previously, although the functional significance of this expression is still being investigated. We provided novel structural and functional information on the expression of the IL-2 receptor in kidney cancer cells and in other normal and neoplastic human epithelial tissues. In A-498 kidney cancer cells, we showed that IL-2 binding to its own receptor triggers a signal transduction pathway leading to the inhibition of proliferation and apoptosis. We found that the inhibition of proliferation is associated with Erk1/2 dephosphorylation, whereas the survival signals appear to be mediated by Sgk1 activation. This investigation focuses on the IL-2 induced regulation of Sgk1 and describes a role of the IL-2 receptor and Sgk1 in the regulation of epithelial tumor cell death and survival.


Assuntos
Apoptose , Proliferação de Células , Proteínas Imediatamente Precoces/fisiologia , Interleucina-2/fisiologia , Neoplasias Renais/patologia , Proteínas Serina-Treonina Quinases/fisiologia , Linhagem Celular Tumoral , Sobrevivência Celular , Regulação da Expressão Gênica , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Neoplasias Renais/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Interleucina-2/análise , Transdução de Sinais
6.
Int J Biochem Cell Biol ; 39(1): 220-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17005433

RESUMO

BRCA1 is a nuclear phosphoprotein that plays a key role in many cell functions, including DNA repair, control of transcription, recombination and cell cycle homeostasis. Inherited missense mutations in the BRCA1 gene may predispose to breast and ovarian cancer, but the molecular mechanisms underlying BRCA1-induced tumorigenesis are still to be elucidated. Functional studies performed so far have contributed to the characterization of several single-nucleotide variants, mostly located at the BRCT domain, but very little is known about modifications in the protein pattern occurring in cells carrying these mutations. To shed more light in the molecular events triggered by missense mutations affecting breast cancer susceptibility genes, we have analyzed the whole cell proteome of stably transfected HeLa cell lines bearing three distinct single aminoacid changes in the BRCA1 protein (Ser1841Asn, Met1775Arg and Trp1837Arg) by means of liquid chromatography coupled to tandem-mass spectrometry. The results show that the Met1775Arg and the Trp1837Arg do not produce significant changes in the proteomic pattern compared to cells transfected with the wild-type BRCA1 cDNA. On the other hand, a different profile is detected in the BRCA1 Ser1841Asn-bearing cell line. In this particular subset, our attention has been focused on two proteins--the tumor protein D52 (TD52) and the folate receptor alpha (FOL1)--whose expression has been already reported to be upregulated in breast cancer, as well as in other tumors. Our findings indicate that Ser1841Asn BRCA1 mutation is able to activate specific protein pathways that are not triggered by other single aminoacid changes and pinpoint to the role TD52 and FOL1 as potential markers in breast cancer patients carrying this particular BRCA1 gene alteration.


Assuntos
Proteína BRCA1/biossíntese , Biomarcadores Tumorais/biossíntese , Neoplasias da Mama/metabolismo , Proteínas de Transporte/biossíntese , Mutação de Sentido Incorreto , Proteínas de Neoplasias/biossíntese , Receptores de Superfície Celular/biossíntese , Substituição de Aminoácidos , Proteína BRCA1/genética , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Proteínas de Transporte/genética , Feminino , Receptores de Folato com Âncoras de GPI , Regulação Neoplásica da Expressão Gênica/genética , Predisposição Genética para Doença , Células HeLa , Humanos , Proteínas de Neoplasias/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Proteômica , Receptores de Superfície Celular/genética
7.
Int J Cancer ; 121(10): 2317-30, 2007 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-17657738

RESUMO

Interferon alpha (IFNalpha) induces an EGF-Ras-->Raf-1-->Erk dependent survival pathway counteracting apoptosis induced by the cytokine. In this paper we have evaluated the effects of the combination between farnesyl-transferase inhibitor (FTI) R115777 and IFNalpha on the growth inhibition and apoptosis of cancer cells. Simultaneous exposure to R115777 and IFNalpha produced synergistic both antiproliferative and proapoptotic effects. In these experimental conditions, IFNalpha and R115777 completely antagonized the increased activity of both Ras and Erk-1/2 induced by IFNalpha and strongly reduced Akt activity. Furthermore, treatment with R115777 in combination with IFNalpha regimen induced tumor growth delay on established KB cell xenografts in nude mice, while the single agents were almost inactive. R115777 was again able to antagonize the Ras-dependent survival pathway induced by IFNalpha also in vivo. Raf-1, one of the downstream targets of Ras, has been reported to activate bcl-2 through displacement and/or phosphorylation of Bad. We have found that IFNalpha induced mitochondrial localization of Raf-1 that was antagonized by R115777. Moreover, IFNalpha increased Raf-1/bcl-2 immuno-conjugate formation and intracellular co-localization and enhanced phosphorylation of Bad at Ser 112 and again R115777 counteracted all these effects. Moreover, the use of plasmids encoding for dominant negative or dominant positive Raf-1 antagonized and potentiated, respectively, the co-immunoprecipitation between Raf-1 and bcl-2. In conclusion, FTI R115777 strongly potentiates the antitumor activity of IFNalpha both in vitro and in vivo through the inhibition of different survival pathways that are dependent from isoprenylation of intracellular proteins such as ras.


Assuntos
Apoptose/efeitos dos fármacos , Farnesiltranstransferase/metabolismo , Interferon-alfa/metabolismo , Quinolonas/toxicidade , Animais , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Imuno-Histoquímica , Interferon-alfa/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Fosfosserina/metabolismo , Transporte Proteico , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-raf/metabolismo , Quinolonas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas ras/metabolismo
8.
Oncogene ; 24(11): 1882-94, 2005 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-15674339

RESUMO

PTEN/MMAC1/TEP1: (hereafter PTEN) is a tumor suppressor gene (located at 10q23) that is frequently mutated or deleted in sporadic human tumors. PTEN encodes a multifunctional phosphatase, which negatively regulates cell growth, migration and survival via the phosphatidylinositol 3'-kinase/AKT signalling pathway. Accordingly, Pten+/- mice develop various types of tumors including teratocarcinomas and teratomas. We have investigated PTEN expression in 60 bioptic specimens of germ cell tumors (32 seminomas, 22 embryonal carcinomas and six teratomas) and 22 intratubular germ cell neoplasias (ITGCN) adjacent to the tumors for PTEN protein and mRNA expression. In total, 10 testicular biopsies were used as controls. In the testis, PTEN was abundantly expressed in germ cells whereas it was virtually absent from 56% of seminomas as well as from 86% of embryonal carcinomas and virtually all teratomas. On the contrary, ITGCN intensely expressed PTEN, indicating that loss of PTEN expression is not an early event in testicular tumor development. The loss of PTEN expression occurs mainly at the RNA level as determined by in situ hybridization of cellular mRNA (17/22) but also it may involve some kind of post-transcriptional mechanisms in the remaining 25% of cases. Analysis of microsatellites D10S551, D10S541 and D10S1765 in GCTs (n=22) showed LOH at the PTEN locus at 10q23 in at least 36% of GCTs (three embryonal carcinoma, three seminoma, two teratoma); one seminoma and one embryonal (9%) carcinoma presented an inactivating mutation in the PTEN gene (2/22). Finally, we demonstrated that the phosphatidylinositol 3'-kinase/AKT pathway, which is regulated by the PTEN phosphatase, is crucial in regulating the proliferation of the NT2/D1 embryonal carcinoma cells, and that the cyclin-dependent kinase inhibitor p27(kip1) is a key downstream target of this pathway.


Assuntos
Transformação Celular Neoplásica , Genes Supressores de Tumor , Germinoma/genética , Monoéster Fosfórico Hidrolases/genética , Neoplasias Testiculares/genética , Proteínas Supressoras de Tumor/genética , Animais , Neoplasias da Mama , Linhagem Celular Tumoral , Cromossomos Humanos Par 10 , Feminino , Citometria de Fluxo , Humanos , Hibridização In Situ , Perda de Heterozigosidade , Masculino , Camundongos , PTEN Fosfo-Hidrolase , RNA Mensageiro/genética , Testículo/citologia , Testículo/embriologia , Testículo/patologia
9.
Hum Mutat ; 27(7): 715, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16786532

RESUMO

The BRCA1 tumor suppressor gene encodes a phosphoprotein involved in many cellular key functions including DNA repair, transcription regulation, cell-cycle control and apoptosis. Most of these functions are strictly related to the ability of BRCA1 to interact with the other partners of a multimeric complex called BASC. Among these components, an important role is played by the human homolog of the bacterial MutL, MLH1. In this study, we have identified the BRCA1 binding domains to MLH1 and demonstrated that three distinct mutations in one of these interaction domains can produce, in vitro, a microsatellite instability phenotype, one of the hallmarks of an imbalance in the mismatch DNA repair machinery. These data support a model in which a structural modification in a critical domain of the BRCA1 gene product secondary to single amino acid mutations, may be able, per se, to impair the DNA damage response pathway, inducing genomic instability and eventually leading to breast carcinogenesis.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Proteínas de Transporte/metabolismo , Genes BRCA1 , Instabilidade Genômica , Mutação de Sentido Incorreto , Proteínas Nucleares/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Alelos , Proteína BRCA1/química , Proteína BRCA1/metabolismo , Sítios de Ligação , Reparo do DNA/fisiologia , Células HeLa , Humanos , Repetições de Microssatélites , Modelos Genéticos , Proteína 1 Homóloga a MutL , Fenótipo , Estrutura Terciária de Proteína , Transfecção
10.
Gene ; 377: 1-5, 2006 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16797877

RESUMO

The H ferritin promoter spans approximately 150 bp, upstream of the transcription start and is composed by two cis-elements in position -132 (A box) and -62 (B-box), respectively. The A box is recognized by the transcription factor Sp1, and the B-box by a protein complex called Bbf, which includes the CAAT binding factor NF-Y. In this study we performed a functional analysis of an H ferritin promoter allele carrying a G to T substitution adjacent to the Bbf binding site, in position -69. In vitro studies with reporter constructs revealed a significantly reduced transcriptional activity of this allele compared to that of the w.t. promoter that was mirrored by a decrease in Bbf binding. In vivo, this variant genotype is accompanied by a reduced amount of the H mRNA in peripheral blood lymphocytes.


Assuntos
Ferritinas/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Alelos , Sequência de Bases , Sítios de Ligação/genética , Fator de Ligação a CCAAT/metabolismo , DNA/genética , DNA/metabolismo , Expressão Gênica , Células HeLa , Humanos , Técnicas In Vitro , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição Sp1/metabolismo , Transcrição Gênica
11.
Eur J Cancer ; 42(11): 1530-8, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16820292

RESUMO

The understanding of molecular events involved in multiple myeloma (MM) development as well as of mechanisms underlying sensitivity/resistance to anticancer drugs has been dramatically increased by the wide-spread use of modern technologies for genetic analysis, global gene expression and proteomic profiling. Such analytical approaches, which are presently supported by reliable bioinformatic tools, have depicted a new scenario for the development of molecular-based anti-MM agents and for predicting clinical outcome. IgH translocations or a hyperdiploid state are emerging as early genetic signatures of MM which lead to deregulated expression of cyclin D. At present however, the major challenge remains the definition of the potential role of cytogenetic techniques and molecular profiling technologies in individual patient management. Here we will describe the prospective potential and current achievements of such technologies which might produce major advancements in the treatment of this still incurable disease.


Assuntos
Análise Citogenética/métodos , Terapia Genética/métodos , Mieloma Múltiplo/genética , Aberrações Cromossômicas , Perfilação da Expressão Gênica/métodos , Humanos , Mieloma Múltiplo/patologia , Mieloma Múltiplo/terapia , Plasmócitos/patologia , Proteômica/métodos
12.
Cancer Chemother Pharmacol ; 57(1): 34-9, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16010592

RESUMO

OBJECTIVE: A combination regimen of temozolomide (TMZ) and pegylated liposomal doxorubicin has been evaluated in the treatment of brain metastases from solid tumours. STUDY DESIGN: Nineteen consecutive patients (pts) have been enrolled in a prospective phase II trial and treated with TMZ 200 mg/m2 (days 1-5) and pegylated liposomal doxorubicin 35 mg/m2 (day 1) every 28 days. The study was prospectively projected according to the Simon's two-stage optimal design. RESULTS: Major toxicities have been grade III neutropenia and thrombocytopenia in one patient (pt) and grade III erythrodisesthesia in two pts. Three pts achieved a complete response (CR) and four a partial response (PR), for an overall response rate of 36.8% (95% CI: 19.1-59.2), which exceeded the target activity in the study design. A significant improvement in quality of life was demonstrated by FACT-G analysis. The median Progression Free Survival (PFS) was 5.5 (95% CI: 2.7-8.2) months while the median Overall Survival (OS) was 10.0 months (95% CI: 6.3-13.7). CONCLUSIONS: The TMZ/pegylated liposomal doxorubicin regimen was well tolerated with an encouraging activity in brain metastases from solid tumours.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/secundário , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Encefálicas/mortalidade , Dacarbazina/administração & dosagem , Dacarbazina/efeitos adversos , Dacarbazina/análogos & derivados , Dacarbazina/uso terapêutico , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Doxorrubicina/uso terapêutico , Esquema de Medicação , Feminino , Humanos , Injeções Intravenosas , Lipossomos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Temozolomida
13.
Oncol Rep ; 16(4): 811-5, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16969499

RESUMO

Women with BRCA1 gene mutations have an increased risk for breast and ovarian cancer (BOC). Classification of missense variants as neutral or disease causing is still a challenge and has major implications for genetic counseling. BRCA1 is organized in an N-terminal ring-finger domain and two BRCT (breast cancer C-terminus) domains, involved in protein-protein interaction. The integrity of the C-terminal, BRCT repeat region is also critical for BRCA1 tumor suppressor function. Several molecular partners of BRCA1 have so far been identified; among them, the tumor suppressor protein p53 seems to play a major role. This study was aimed at evaluating the impact of two missense mutations, namely the W1837R and the S1841N, previously identified in BOC patients and located in the BRCT domain of the BRCA1 gene, on the binding capacity of this protein to p53. Co-immunoprecipitation assays of E. coli-expressed wild-type and mutated BRCTs challenged with a HeLa cell extract revealed, for the S1841N variant a significant reduction in the binding activity to p53, while the W1837R mutant showed an inverse effect. Furthermore, a clonogenic soft agar growth assay performed on HeLa cells stably transfected with either wild-type or mutant BRCA1 showed a marked decrease of the growth in wild-type BRCA1-overexpressing cells and in BRCA1S1841N-transfected cells, while no significant changes were detected in the BRCA1W1837R-transfected cells. These results demonstrate that: i) distinct single nucleotide changes in the BRCT domain of BRCA1 affect binding of this protein to the tumor suppressor p53, and ii) the two missense mutations here described are likely to play a role in breast tumorigenesis. We suggest that in vitro/in vivo experiments testing the effects of unclassified BRCA1 gene variants should therefore be taken in to consideration and that increased surveillance should be adopted in individuals bearing these two BRCA1 missense alterations.


Assuntos
Neoplasias da Mama/genética , Genes BRCA1 , Mutação de Sentido Incorreto , Proteína Supressora de Tumor p53/metabolismo , Ágar/química , Alelos , Neoplasias da Mama/metabolismo , Proliferação de Células , Escherichia coli/metabolismo , Feminino , Células HeLa , Humanos , Técnicas In Vitro , Modelos Genéticos , Ligação Proteica , Estrutura Terciária de Proteína
14.
Clin Cancer Res ; 11(11): 4251-8, 2005 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15930364

RESUMO

Interleukin-6 (IL-6) protects multiple myeloma cells against apoptosis induced by glucocorticoids. Here, we investigated whether inhibition of the IL-6 signaling pathway by the IL-6 receptor superantagonist Sant7 enhances the in vivo antitumor effects of dexamethasone on the IL-6-dependent multiple myeloma cell line INA-6. For this purpose, we used a novel murine model of human multiple myeloma in which IL-6-dependent INA-6 multiple myeloma cells were directly injected into human bone marrow implants in severe combined immunodeficient (SCID) mice (SCID-hu). The effect of in vivo drug treatments on multiple myeloma cell growth was monitored by serial determinations of serum levels of soluble IL-6 receptor (shuIL-6R), which is released by INA-6 cells and served as a marker of tumor growth. In SCID-hu mice engrafted with INA-6 cells, treatment with either Sant7 or dexamethasone alone did not induce significant reduction in serum shuIL-6R levels. In contrast, the combination of Sant7 with dexamethasone resulted in a synergistic reduction in serum shuIL-6R levels after 6 consecutive days of treatment. Gene expression profiling of INA-6 cells showed down-regulation of proliferation/maintenance and cell cycle control genes, as well as up-regulation of apoptotic genes in multiple myeloma cells triggered by Sant7 and dexamethasone combination. In vitro colony assays showed inhibition of myeloid and erythroid colonies from normal human CD34(+) progenitors in response to dexamethasone, whereas Sant7 neither inhibited colony growth nor potentiated the inhibitory effect of dexamethasone. Taken together, these results indicate that inhibition of IL-6 signaling by Sant7 significantly potentiates the therapeutic action of dexamethasone against multiple myeloma cells, providing the preclinical rationale for clinical trials of Sant7 in combination with dexamethasone to improve patient outcome in multiple myeloma.


Assuntos
Dexametasona/farmacologia , Interleucina-6/análogos & derivados , Mieloma Múltiplo/tratamento farmacológico , Receptores de Interleucina-6/antagonistas & inibidores , Animais , Antígenos CD34/análise , Antineoplásicos Hormonais/administração & dosagem , Antineoplásicos Hormonais/uso terapêutico , Apoptose/genética , Linhagem Celular Tumoral , Análise por Conglomerados , Ensaio de Unidades Formadoras de Colônias , Dexametasona/uso terapêutico , Modelos Animais de Doenças , Sinergismo Farmacológico , Quimioterapia Combinada , Citometria de Fluxo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/imunologia , Humanos , Interleucina-6/farmacologia , Interleucina-6/uso terapêutico , Masculino , Camundongos , Camundongos SCID , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Receptores de Interleucina-6/metabolismo
15.
Cancer Res ; 64(13): 4629-36, 2004 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-15231675

RESUMO

HuN901 is a humanized monoclonal antibody that binds with high affinity to CD56, the neuronal cell adhesion molecule. HuN901 conjugated with the maytansinoid N(2')-deacetyl-N(2')-(3-mercapto-1-oxopropyl)-maytansine (DM1), a potent antimicrotubular cytotoxic agent, may provide targeted delivery of the drug to CD56 expressing tumors. Based on gene expression profiles of primary multiple myeloma (MM) cells showing expression of CD56 in 10 out of 15 patients (66.6%) and flow cytometric profiles of MM (CD38(bright)CD45(lo)) cells showing CD56 expression in 22 out of 28 patients (79%), we assessed the efficacy of huN901-DM1 for the treatment of MM. We first examined the in vitro cytotoxicity and specificity of huN901-DM1 on a panel of CD56(+) and CD56(-) MM cell lines, as well as a CD56(-) Waldenstrom's macroglobulinemia cell line. HuN901-DM1 treatment selectively decreased survival of CD56(+) MM cell lines and depleted CD56(+) MM cells from mixed cultures with a CD56(-) cell line or adherent bone marrow stromal cells. In vivo antitumor activity of huN901-DM1 was then studied in a tumor xenograft model using a CD56(+) OPM2 human MM cell line in SCID mice. We observed inhibition of serum paraprotein secretion, inhibition of tumor growth, and increase in survival of mice treated with huN901-DM1. Our data therefore demonstrate that huN901-DM1 has significant in vitro and in vivo antimyeloma activity at doses that are well tolerated in a murine model. Taken together, these data provide the framework for clinical trials of this agent to improve patient outcome in MM.


Assuntos
Anticorpos Monoclonais/farmacologia , Antígeno CD56/metabolismo , Imunotoxinas/farmacologia , Maitansina/farmacologia , Mieloma Múltiplo/tratamento farmacológico , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/metabolismo , Antígeno CD56/biossíntese , Adesão Celular/fisiologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Imunotoxinas/metabolismo , Masculino , Maitansina/administração & dosagem , Maitansina/análogos & derivados , Camundongos , Camundongos SCID , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/metabolismo , Moléculas de Adesão de Célula Nervosa/biossíntese , Moléculas de Adesão de Célula Nervosa/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Oncogene ; 23(41): 6900-13, 2004 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-15286715

RESUMO

Pamidronate (PAM) and zoledronic acid (ZOL) are aminobisphosphonates (BPs) able to affect the isoprenylation of intracellular small G proteins. We have investigated the antitumor activity of BPs and R115777 farnesyl transferase inhibitor (FTI) against epidermoid cancer cells. In human epidermoid head and neck KB and lung H1355 cancer cells, 48 h exposure to PAM and ZOL induced growth inhibition (IC(50) 25 and 10 microM, respectively) and apoptosis and abolished the proliferative and antiapoptotic stimuli induced by epidermal growth factor (EGF). In these experimental conditions, ZOL induced apoptosis through the activation of caspase 3 and a clear fragmentation of PARP was also demonstrated. A strong decrease of basal ras activity and an antagonism on its stimulation by EGF was recorded in the tumor cells exposed to BPs. These effects were paralleled by impaired activation of the survival enzymes extracellular signal regulated kinase 1 and 2 (Erk-1/2) and Akt that were not restored by EGF. Conversely, farnesol induced a recovery of ras activity and antagonized the proapoptotic effects induced by BPs. The combined treatment with BPs and R115777 resulted in a strong synergism both in growth inhibition and apoptosis in KB and H1355 cells. The synergistic activity between the drugs allowed BPs to produce tumor cell growth inhibition and apoptosis at in vivo achievable concentrations (0.1 micromolar for both drugs). Moreover, the combination was highly effective in the inhibition of ras, Erk and Akt activity, while farnesol again antagonized these effects. In conclusion, the combination of BPs and FTI leads to enhanced antitumor activity at clinically achievable drug concentrations that resides in the inhibition of farnesylation-dependent survival pathways and warrants further studies for clinical translation.


Assuntos
Alquil e Aril Transferases/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Difosfonatos/farmacologia , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Células KB/efeitos dos fármacos , Quinolonas/farmacologia , Caspases/fisiologia , Divisão Celular/efeitos dos fármacos , Sinergismo Farmacológico , Fator de Crescimento Epidérmico/farmacologia , Farnesiltranstransferase , Humanos , Células KB/citologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Pamidronato , Prenilação de Proteína , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ácido Zoledrônico
17.
Cancer Lett ; 223(2): 285-91, 2005 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-15896463

RESUMO

Germline mutations within the mismatch repair (MMR) genes are generally found in colorectal cancer (CRC) patients with a positive family history for the presence of the neoplasia. Clinical standard criteria have been established to define hereditary-non-polyposis-colorectal cancer (HNPCC)-prone families. Interestingly, the number of MMR gene mutations found in kindreds not fulfilling these criteria is still increasing. In this work we report the identification of a novel germline mutation of the hMSH2 gene, in two CRC-bearing subjects. The two probands belong to a large kindred from South Italy with no history suggestive for cancer aggregation. On the other hand, the early-onset of the neoplasia as well as the presence of a high number of tumor infiltrating lymphocytes (TILs) in the histological specimens of both patients, prompted us to perform a comprehensive genetic analysis. This analysis included the evaluation of the microsatellite instability (MSI) status with five markers according to the National Cancer Institute recommendations, followed by direct sequencing of the hMLH1 and hMSH2 genes. Both probands were found to carry a germline missense (277 C>T) mutation leading to the change (L93F) of an amino acid residue in a highly conserved domain of the MSH2 protein. This mutation is accompanied by the loss of expression of the hMSH2 gene in the tumor tissue. Our findings suggest that in the presence of the above-mentioned criteria it may be useful to perform a molecular analysis of the MMR genes, even if the pedigree does not show marked aggregation of cancers.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Mutação de Sentido Incorreto , Proteínas Proto-Oncogênicas/genética , Adulto , Pareamento Incorreto de Bases , Estudos de Casos e Controles , Análise Mutacional de DNA , Reparo do DNA , Enzimas Reparadoras do DNA , Éxons , Feminino , Regulação Neoplásica da Expressão Gênica , Mutação em Linhagem Germinativa , Humanos , Imuno-Histoquímica , Itália , Masculino , Repetições de Microssatélites , Proteína 2 Homóloga a MutS , Linhagem
18.
Int J Oncol ; 26(5): 1257-63, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15809716

RESUMO

Germ-line mutations in the breast cancer susceptibility BRCA1 gene account for approximately half of hereditary breast cancer cases and most of breast/ovarian cancer cases. We speculated whether breast hereditary cancers might be differentially sensitive to antitumor agents such as the mitotic spindle poisons Vinca alcaloid vinorelbine (VNR) and the taxoid docetaxel (DOC), which are commonly used in the treatment of breast cancer. We investigated the sensitivity of the BRCA1-mutated HCC1937 (derived from a BRCA1 related hereditary tumor) and BRCA1 competent MCF-7 and MDA-MB468 sporadic breast cancer cell lines to these drugs. We found that HCC1937 cells were significantly more sensitive to VNR as compared to MCF-7 or MDA-MB468 cells. Instead, BRCA1-mutated breast cancer cells exposed to DOC showed similar sensitivity as compared to BRCA1-competent MCF-7 or were less sensitive than MDA-MB468. In order to assess the role of BRCA1 in this specific pattern of chemosensitivity, we transfected the BRCA1-mutated HCC1937 cells with a full-length BRCA1 cDNA and the stable clone (HCC1937/WTBRCA1) was exposed to both drugs. Full-length BRCA1 transfection led to a significant induction of resistance to VNR, whereas only a weak but not significant increase of sensitivity to DOC was detected. Moreover, VNR induced apoptotic cell death and cytoskeletal rearrangements in HCC1937 cells. We further investigated whether a defective targeting of mitotic spindle by the mutated BRCA1 gene product might be involved in the differential sensitivity to VNR. We demonstrated that mutated BRCA1 was indeed capable of co-localizing with alpha-tubulin in the mitotic spindle, suggesting therefore that different mechanisms should account for these effects. In conclusion, our data suggest that BRCA1-mutated tumors might be differentially sensitive to anti-microtubule agents, supporting the rationale for clinical trials to improve the outcome of hereditary breast cancer patients by tailored treatments.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/genética , Genes BRCA1 , Taxoides/farmacologia , Vimblastina/análogos & derivados , Vimblastina/farmacologia , Apoptose , Neoplasias da Mama/patologia , Citoesqueleto/patologia , Análise Mutacional de DNA , Docetaxel , Resistencia a Medicamentos Antineoplásicos , Feminino , Mutação em Linhagem Germinativa , Humanos , Microtúbulos/patologia , Fuso Acromático/patologia , Células Tumorais Cultivadas , Vinorelbina
19.
Am J Obstet Gynecol ; 193(4): 1344-52, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16202724

RESUMO

OBJECTIVE: This study was undertaken to compare the quality of life (QoL) in women with early stage endometrial cancer treated with 2 different surgical approaches. STUDY DESIGN: Eighty-four women with clinical stage I endometrial cancer were enrolled in a prospective randomized controlled trial design and treated with laparoscopic or laparotomic approach. Another 40 women matched for demographic characteristics were studied as controls. In patients, before and after surgery, and in their matched controls, QoL was evaluated by using the Short-Form Healthy Survey (SF-36) and the climacteric symptoms using the Kupperman Index (KI). RESULTS: After randomization, no difference was detected in data recorded between the groups. At entry, QoL was similar in both treatment groups but significantly (P < .05) worse in comparison with controls. Throughout the study, QoL was significantly (P < .05) higher in laparoscopic group versus laparotomic group. After KI adjustment our data did not change. CONCLUSION: In early stage endometrial cancer, the laparoscopic approach provides significant benefits compared with laparotomy in terms of QoL.


Assuntos
Neoplasias do Endométrio/cirurgia , Laparoscopia , Laparotomia , Qualidade de Vida , Neoplasias do Endométrio/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Prospectivos
20.
Eur J Cancer ; 40(18): 2829-36, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15571967

RESUMO

Inhibition of nuclear factor (NF)-kappaB/Rel can sensitise many tumour cells to death-inducing stimuli, including chemotherapeutic agents, and there are data suggesting that disruption of NF-kappaB may be of therapeutic interest in melanoma. We found that rapamycin sensitised a human melanoma cell line, established from a patient, to the cytolytic effects of doxorubicin. Doxorubicin is a striking NF-kappaB/Rel-inducer, we therefore investigated if rapamycin interfered with the pathway of NF-kappaB/Rel activation, i.e. IkappaBalpha-phosphorylation, -degradation and NF-kappaB/Rel nuclear translocation, and found that the macrolide agent caused a block of IKK kinase activity that was responsible for a reduced nuclear translocation of transcription factors. Western blots for Bcl-2 and c-IAP1 showed increased levels of these anti-apoptotic proteins in cells incubated with doxorubicin, in accordance with NF-kappaB/Rel activation, while rapamycin clearly downmodulated these proteins, in line with its pro-apoptotic ability. The effect of the macrolide on NF-kappa B/Rel induction appeared to be independent of the block in the PI3k/Akt pathway, because it could not be reproduced by the phosphatidyl inositol 3 kinase (PI3k) inhibitor, wortmannin. Recently, the immunophilin, FKBP51, has been shown to be essential for the function of IKK kinase. We found high expression levels of FKBP51 in melanoma cells. Moreover, we confirmed the involvement of this immunophilin in the control of IKK activity. Indeed, IkappaBalpha could not be degraded when FKBP51 was downmodulated by short-interfering RNAs (siRNAs). These findings provide a possible mechanism for the downmodulation of NF-kappaB by rapamycin, since the macrolide agent specifically inhibits FKBP51 isomerase activity. In conclusion, our study demonstrates that rapamycin blocked NF-kappaB/Rel activation independently of PI3k/Akt inhibition suggesting that the macrolide agent could synergise with NF-kappaB-inducing anti-cancer drugs in PTEN-positive tumours.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Doxorrubicina/farmacologia , Melanoma/patologia , NF-kappa B/antagonistas & inibidores , Sirolimo/farmacologia , Androstadienos/farmacologia , Western Blotting , Linhagem Celular Tumoral , Humanos , Proteínas Inibidoras de Apoptose , Melanoma/tratamento farmacológico , NF-kappa B/efeitos dos fármacos , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Neoplásico/análise , Fator de Transcrição RelA , Transfecção , Ubiquitina-Proteína Ligases , Wortmanina
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