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1.
Support Care Cancer ; 16(8): 869-77, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18224349

RESUMO

GOALS OF WORK: The way to inform cancer patients varies widely among different countries. In most Mediterranean countries, the traditional approach has been of partial disclosure of the truth. The intent of our work was to find if the attitude in Italy has changed in recent years and if differences still exist among different geographical regions in our country. Both patients' and physicians' attitudes vary in Italy depending on geographical area. In the South, the focus is on traditional values and full involvement of patients' family, with limited communication to (and limited autonomy of) the patient. Such attitude is less pronounced in Central Italy, whereas the North is more oriented to open communication and full decisional autonomy of the patient. MATERIALS AND METHODS: Approximately 600 consecutive patients in three different centres in Northern, Central and Southern Italy (respectively, Udine, Ancona and Catanzaro) were asked to answer a 26-item questionnaire on communication aspects to investigate the quality of the information given and potential differences between geographical areas. RESULTS: Questionnaires were completed by 587 patients (median age 60 years, 57% women), mainly with gastrointestinal (32%) or breast cancer (30%). About 370 patients (63%) had active disease at time of interview. A high proportion of patients were correctly informed on diagnosis (86%) and therapy (84%). On the contrary, patients fully aware of their prognosis were only about 43%. Nevertheless, most patients (60%) stated they were completely satisfied with the information received. There were differences between geographical areas on various information aspects, with patients from Southern Italy being, in general, less informed. CONCLUSIONS: In Italy, the cultural attitude towards communication in oncology is changing on both the physician and the patient side. There are still significant geographical differences, but there is a general trend suggesting improved awareness about diagnosis and treatment, with the notable exception of prognosis.


Assuntos
Acesso à Informação , Neoplasias , Educação de Pacientes como Assunto , Institutos de Câncer , Comunicação , Características Culturais , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Relações Médico-Paciente , Prognóstico , Inquéritos e Questionários
2.
Leukemia ; 21(12): 2519-26, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17882285

RESUMO

Atiprimod (Atip) is a novel oral agent with anti-inflammatory properties. Although its in vitro activity and effects on signaling in multiple myeloma (MM) have been previously reported, here we investigated its molecular and in vivo effects in MM. Gene expression analysis of MM cells identified downregulation of genes involved in adhesion, cell-signaling, cell cycle and bone morphogenetic protein (BMP) pathways and upregulation of genes implicated in apoptosis and bone development, following Atip treatment. The pathway analysis identified integrin, TGF-beta and FGF signaling as well as Wnt/beta-catenin, IGF1 and cell-cycle regulation networks as being most modulated by Atip treatment. We further evaluated its in vivo activity in three mouse models. The subcutaneous model confirmed its in vivo activity and established its dose; the SCID-hu model using INA-6 cells, confirmed its ability to overcome the protective effects of BM milieu; and the SCID-hu model using primary MM cells reconfirmed its activity in a model closest to human disease. Finally, we observed reduced number of osteoclasts and modulation of genes related to BMP pathways. Taken together, these data demonstrate the in vitro and in vivo antitumor activity of Atip, delineate potential molecular targets triggered by this agent, and provide a preclinical rational for its clinical evaluation in MM.


Assuntos
Antineoplásicos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Redes e Vias Metabólicas/efeitos dos fármacos , Mieloma Múltiplo/tratamento farmacológico , Compostos de Espiro/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Reabsorção Óssea/tratamento farmacológico , Adesão Celular/efeitos dos fármacos , Adesão Celular/genética , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/metabolismo , Linhagem Celular Tumoral/transplante , Perfilação da Expressão Gênica , Humanos , Redes e Vias Metabólicas/genética , Camundongos , Camundongos Nus , Camundongos SCID , Mieloma Múltiplo/metabolismo , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Transdução de Sinais/efeitos dos fármacos , Compostos de Espiro/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Cell Death Differ ; 14(5): 952-62, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17332776

RESUMO

Interferon alpha (IFNalpha) induces both apoptosis and a counteracting epidermal growth factor Erk-dependent survival response in cancer cells. In this report, IFNalpha increased eukaryotic elongation factor 1A (eEF-1A) protein expression by inhibition of eEF-1A degradation via a proteasome-dependent pathway. The reduction of the expression level of eEF-1A by RNA interference enhanced the apoptosis induced by IFNalpha on the same cells. Moreover, IFNalpha induced the phosphorylation of both serine and threonine in eEF-1A. These effects were paralleled by an increased co-immunoprecipitation and colocalization of eEF-1A with C-Raf. The suppression of C-Raf kinase activity with the inhibitor BAY 43-9006 completely antagonized the increase of both eEF-1A phosphorylation and expression and of C-Raf/eEF-1A colocalization induced by IFNalpha and enhanced apoptosis and eEF-1A ubiquitination. Cell transfection with the mutated K48R ubiquitin increased EF-1A expression and desensitized tumor cells to the modulating effects of IFNalpha. The dynamic simulation of 3Dstructure of eEF-1A identified putative serine and threonine phosphorylation sites. In conclusion, the interaction between eEF-1A and C-Raf increases eEF-1A stability and induces a survival activity.


Assuntos
Apoptose/efeitos dos fármacos , Interferon-alfa/farmacologia , Neoplasias Pulmonares/patologia , Proteínas Oncogênicas/metabolismo , Fator 1 de Elongação de Peptídeos/metabolismo , Proteínas Proto-Oncogênicas c-raf/metabolismo , Linhagem Celular Tumoral , Humanos , Imunoprecipitação , Neoplasias Pulmonares/metabolismo , Fosforilação/efeitos dos fármacos , Fosfosserina/metabolismo , Fosfotreonina/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , RNA Interferente Pequeno/metabolismo , Ubiquitina/metabolismo
6.
Ann Oncol ; 17 Suppl 7: vii124-7, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16760274

RESUMO

Target-based therapy has been a promising anti-cancer strategy in the preclinical setting, but its efficacy is still limited in clinical practice. The latter was probably due to the lack of identification of molecular targets in order to predict clinical response and for the existence of multiple survival compensatory downstream pathways. Therefore, the use of downstream targets could be useful in order to avoid these overcoming pathways. One of these targets is Raf-kinase. In this review we describe the structure and functions of the components of Raf-kinase family and their relevance in proliferation and survival of tumor cells. Moreover, we illustrate the signal transduction pathways regulated by Raf-kinases. The main preclinical and clinical results obtained with the use of the Raf-kinase inhibitor BAY 43-9006 or sorafenib are also described. The multi-target function of sorafenib is also explained and the disclosure of new therapeutic opportunities based on the dual inhibition of cancer proliferation and neo-angiogenesis is discussed. In conclusion, Raf-kinase appears an appealing therapeutic target, even it other preclinical and clinical studies are warranted in order to evaluate the activity of sorafenib both in monotherapy and in combination with other agents.


Assuntos
Antineoplásicos/farmacologia , Benzenossulfonatos/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Quinases raf/antagonistas & inibidores , Animais , Humanos , Niacinamida/análogos & derivados , Compostos de Fenilureia , Sorafenibe , Quinases raf/metabolismo
7.
Int J Biol Macromol ; 39(1-3): 122-6, 2006 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-16580720

RESUMO

UN1 is a membrane glycoprotein that is expressed in immature human thymocytes, a subpopulation of peripheral T lymphocytes, the HPB acute lymphoblastic leukemia (ALL) T-cell line and fetal thymus. We previously reported the isolation of a monoclonal antibody (UN1 mAb) recognizing the UN1 protein that was classified as "unclustered" at the 5th and 6th International Workshop and Conference on Human Leukocyte Differentiation Antigens. UN1 was highly expressed in breast cancer tissues and was undetected in non-proliferative lesions and in normal breast tissues, indicating a role for UN1 in the development of a tumorigenic phenotype of breast cancer cells. In this study, we report a partial purification of the UN1 protein from HPB-ALL T cells by anion-exchange chromatography followed by immunoprecipitation with the UN1 mAb and MALDI-TOF MS analysis. This analysis should assist in identifying the amino acid sequence of UN1.


Assuntos
Antígenos de Neoplasias/isolamento & purificação , Glicoproteínas/isolamento & purificação , Proteínas de Membrana/isolamento & purificação , Sialoglicoproteínas/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Antígenos de Neoplasias/química , Antígenos de Neoplasias/metabolismo , Neoplasias da Mama/química , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Feto/química , Feto/metabolismo , Glicoproteínas/química , Glicoproteínas/metabolismo , Humanos , Leucossialina , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Sialoglicoproteínas/química , Sialoglicoproteínas/metabolismo , Timo/química , Timo/metabolismo
8.
Int J Gynecol Cancer ; 16 Suppl 1: 79-85, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16515572

RESUMO

We carried out a phase II nonrandomized study to examine the level of activity of oxaliplatin, pegylated liposomal doxorubicin, and cyclophosphamide in a patient population with relapsed ovarian cancer pretreated with platinum derivatives and paclitaxel. Patients received oxaliplatin (85 mg/m2), pegylated liposomal doxorubicin (30 mg/m2), and cyclophosphamide (750 mg/m2). A total of 49 patients (39 assessable for toxicity and response) were enrolled in this trial. Neutropenia grade 3 was observed in six patients (15%) and anemia grade 3 in one patient (0.2%). Fatigue grade 1-2 occurred in 26 patients (66%), nausea/vomiting grade 1 in 23 patients (58%), and alopecia grade 1-2 in 19 patients (48%). Twenty-one (53%) patients experienced grade 1-2 peripheral neuropathy. The overall response rate was 46% (95% CI 23.6-68.7). Median progression-free survival was 28 weeks (range 12-52 weeks) and median survival was 45 weeks (range 26-136+ weeks). The mean duration of response was 34 weeks (range 16-52 weeks). In platinum-resistant and -refractory ovarian cancer patients, the overall response rate was 37% (CI 95% 14.4-60.8) with a progression-free survival of 28 weeks (range 12-52 weeks) and a median survival of 42 weeks (range 28-84 weeks). This combination chemotherapy is generally well tolerated and is an active second-line regimen against ovarian cancer.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Doxorrubicina/análogos & derivados , Feminino , Humanos , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Polietilenoglicóis/administração & dosagem , Análise de Sobrevida
10.
Anticancer Res ; 25(2A): 1023-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15868942

RESUMO

The biological effects produced by low power millimeter waves (MMW) were studied on the RPMI 7932 human melanoma cell line. Three different frequency-type irradiation modes were used: the 53.57-78.33 GHz wide-band frequency range, the 51.05 GHz and the 65.00 GHz monochromatic frequencies. In all three irradiation conditions, the radiation energy was low enough not to increase the temperature of the cellular samples. Three hours of radiation treatment, applied every day to the melanoma cell samples, were performed at each frequency exposure condition. The wide-band irradiation treatment effectively inhibited cell growth, while both the monochromatic irradiation treatments did not affect the growth trend of RPMI 7932 cells. A light microscopy analysis revealed that the low-intensity wide-band millimeter radiation induced significant morphological alterations on these cells. Furthermore, a histochemical study revealed the low proliferative state of the irradiated cells. This work provides further evidence of the antiproliferative effects on tumor cells induced by low power MMW in the 50-80 GHz frequency range of the electromagnetic spectrum.


Assuntos
Campos Eletromagnéticos , Melanoma/radioterapia , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Humanos , Luz , Melanoma/patologia , Microscopia , Micro-Ondas
11.
Curr Drug Targets ; 6(3): 289-300, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15857289

RESUMO

Cellular receptors for the Epidermal Growth Factor are considered important targets for the experimental treatment of human cancer. Monoclonal antibodies as well as small tyrosine kinase inhibitors have been developed and have undergone extensive evaluation in preclinical and clinical studies. Most of these studies have been conceived on the general idea that epidermal growth factor receptor (EGFR) plays a critical role on the growth and survival of human tumors. This assumption has been derived by the successful development of BCR/ABL tyrosine kinase inhibitors in human chronic myeloid leukemia as well as on the activity of antiCD20 monoclonal antibodies in lymphoproliferative disease and of anti HER2 agents in breast tumors overexpressing the targeted antigens. It is now becoming clear that factors regulating sensitivity to kinase inhibitors may differ from monoclonal antibodies and that the molecules targeted by interferring drugs must be prioritaire for growth and survival of those specific tumors in order to achieve valuable results. Recent evidence of major responses to the EGFR inhibitor Gefitinib in tumors harboring activating mutations in the EGFR appears on line with this concept. In this article we will discuss the significance of targeting the EGFR driven survival pathways. Specifically, we will afford the point of EGFR survival signalling prioritization by means of pharmacological treatment. Finally, we will address the role of profiling technologies and of novel computational system biology-based approaches for identification of innovative strategies for effective targeting of EGFR driven survival pathways.


Assuntos
Antineoplásicos/uso terapêutico , Receptores ErbB/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Animais , Apoptose , Sobrevivência Celular , Dimerização , Receptores ErbB/genética , Receptores ErbB/fisiologia , Humanos , Mutação , Interferência de RNA , Transdução de Sinais
12.
Ann Oncol ; 15(5): 726-32, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15111339

RESUMO

BACKGROUND: We describe a multistep model of cancer genetic counselling designed to promote awareness, and disease surveillance and preventive measures for hereditary and familial breast and ovarian cancer. PATIENTS AND METHODS: Step T0 of the model entails information giving; this is followed by pedigree analysis and risk estimation (T1), risk communication and genetic testing (T2), and genetic test result communication (T3). User consent was required to proceed from one step to the next. Surveillance and preventive measures are proposed to at-risk users. Of the 311 subjects who requested cancer genetic counselling, consent data to each counselling step were available for 295: 93 were disease-free, 187 had breast cancer, 12 had ovarian cancer and three had breast plus ovarian cancer. RESULTS: Consent was high at T0 (98.39%), T1 (96.40%) and T2 (99.65%). Consent decreased at the crucial points of counselling: T2 (87.71%) and T3 [genetic test result communication (85.08%), and extension of counselling to and testing of relatives (65.36%)]. CONCLUSIONS: The model fosters the user's knowledge about cancer and favours identification of at-risk subjects. Furthermore, by promoting awareness about genetic testing and surveillance measures, the algorithm enables users to make a fully informed choice of action in case of predisposing or familial cancer risk.


Assuntos
Neoplasias da Mama/genética , Aconselhamento Genético , Predisposição Genética para Doença , Testes Genéticos , Consentimento Livre e Esclarecido , Neoplasias Ovarianas/genética , Feminino , Humanos , Educação de Pacientes como Assunto , Linhagem , Fatores de Risco
14.
Leukemia ; 18(1): 11-7, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14574329

RESUMO

The activity of NF-kappaB/Rel transcription factors can downmodulate apoptosis in normal and neoplastic cells of the hematologic and other compartments, contributing in maintaining neoplastic clone survival and impairing response to therapy. Alterations in nfkappab or ikappaB genes are documented in some hematologic neoplasias, while in others dysfunction in NF-kappaB/Rel-activating signaling pathways can be recognized. The prosurvival properties of NF-kappaB/Rel appear to rely on the induced expression of molecules (caspase inhibitors, Bcl2 protein family members, etc.), which interfere with the apoptosis pathway. Constitutive NF-kappaB/Rel activity in some hematologic malignancies could be advantageous for neoplastic clone expansion by counteracting stress stimuli (consumption of growth factors and metabolites) and immune system-triggered apoptosis; it is furthermore likely to play a central role in determining resistance to therapy. Based on this evidence, NF-kappaB/Rel-blocking approaches have been introduced in antineoplastic strategies. The identification of NF-kappaB/Rel target genes relevant for survival in specific neoplasias is required in order to address tailored therapies and avoid possible detrimental effects due to widespread NF-kappaB/Rel inhibition. Moreover, comparative analyses of normal hematopoietic progenitors and neoplastic cell sensitivities to inhibitors of NF-kappaB/Rel and their target genes will allow to evaluate the impact of these tools on normal bone marrow.


Assuntos
Apoptose , Neoplasias Hematológicas/patologia , Células-Tronco Hematopoéticas/patologia , NF-kappa B/fisiologia , Proteínas Proto-Oncogênicas c-rel/fisiologia , Animais , Humanos , Transdução de Sinais/efeitos dos fármacos
15.
J Biochem ; 133(6): 757-65, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12869532

RESUMO

Interferon-alpha (IFNalpha) can induce apoptosis, a process regulated by a complex network of cell factors. Among these, eukaryotic initiation factor-5A (eIF-5A) is peculiar because its activity is modulated by the post-translational formation of the amino acid hypusine. Here we report the effects of IFNalpha and epidermal growth factor (EGF) on apoptosis and eIF-5A activity in human epidermoid oropharyngeal KB and lung H1355 cancer cells. We found that 48-h exposure to 1000 and 2000 IU/ml IFNalpha induced about 50% growth inhibition and apoptosis in H1355 and KB cells, respectively, and the addition of EGF completely antagonized this effect. When IFNalpha induced apoptosis, a hyperactivation of MEK-1 and ERK signalling and a decrease of the hypusine-containing form and, thus, of eIF-5A activity were recorded. The latter effect was again antagonized by the addition of EGF to IFNalpha-pretreated cells, probably through the activation of the EGF-->ERK-dependent pathway, since the addition of the specific MEK-1 inhibitor PD098059 abrogated the recovery of intracellular hypusine content induced by EGF in IFNalpha-pretreated cancer cells. Subsequently, we evaluated if the hypusine synthesis inhibitor (and eIF-5A inactivator) N1-guanyl-1,7-diaminoheptane (GC7) synergized with IFNalpha in the induction of cell growth inhibition and apoptosis. The analysis of the isobologram of IFNalpha and GC7 demonstrated a strong synergism between the two drugs in inducing cell growth inhibition. We also found that GC7 and IFNalpha had a synergistic effect on apoptosis. These data suggest that the apoptosis induced by IFNalpha could be regulated by eIF-5A that, therefore, could represent a useful target for the potentiation of IFNalpha antitumor activity.


Assuntos
Antineoplásicos/farmacologia , Fator de Crescimento Epidérmico/farmacologia , Guanina/análogos & derivados , Interferon-alfa/farmacologia , Lisina/análogos & derivados , Fatores de Iniciação de Peptídeos/metabolismo , Proteínas de Ligação a RNA , Apoptose , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Guanina/farmacologia , Humanos , Células KB , Lisina/biossíntese , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fatores de Iniciação de Peptídeos/antagonistas & inibidores , Fosforilação , Processamento de Proteína Pós-Traducional , Fator de Iniciação de Tradução Eucariótico 5A
16.
Br J Cancer ; 88(12): 1971-8, 2003 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-12799645

RESUMO

Bisphosphonates (BPs) are an emerging class of drugs mostly used in the palliative care of cancer patients. We investigated the in vitro activity of the most potent antiresorptive BP, zoledronic acid (ZOL), on the growth and survival of three human pancreatic cancer (PC) cell lines (BxPC-3, CFPAC-1 and PANC-1). Pancreatic cancer frequently has a dysregulated p21(ras) pathway and therefore appears to be a suitable target for BPs that interfere with the prenylation of small GTP-binding proteins such as p21(ras). We found that ZOL induces growth inhibition (IC(50):10-50 micro M) and apoptotic death of PC cells. The proapoptotic effect was correlated to cleavage/activation of caspase-9 and poly(ADP)-ribose polymerase, but not of caspase-3. Moreover, we studied the p21(ras) signalling in cells exposed to ZOL and detected a reduction of p21(ras) and Raf-1 content and functional downregulation of the terminal enzyme ERK/MAPkinase and of the pKB/Akt survival pathway. Finally, we observed that ZOL induces significant cytoskeletal rearrangements. In conclusion, we demonstrated that ZOL induces growth inhibition and apoptosis on PC cells and interferes with growth and survival pathways downstream to p21(ras). These findings might be relevant for expanding application of BPs in cancer treatment.


Assuntos
Apoptose/efeitos dos fármacos , Difosfonatos/farmacologia , Imidazóis/farmacologia , Neoplasias Pancreáticas/tratamento farmacológico , Divisão Celular/efeitos dos fármacos , Humanos , MAP Quinase Quinase 1 , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-raf/metabolismo , Células Tumorais Cultivadas , Ácido Zoledrônico
18.
Br J Cancer ; 88(8): 1285-91, 2003 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-12698198

RESUMO

Germline mutations of the tumour suppressor gene BRCA1 are involved in the predisposition and development of breast cancer and account for 20-45% of all hereditary cases. There is an increasing evidence that these tumours are characterised by a specific phenotype and pattern of gene expression. We have hypothesised that differences in chemosensitivity might parallel molecular heterogeneity of hereditary and sporadic breast tumours. To this end, we have investigated the chemosensitivity of the BRCA1-defective HCC1937 breast cancer cell line, and the BRCA1-competent MCF-7 (hormone-sensitive) and MDA-MB231 (hormone-insensitive) breast cancer cell lines using the MTT assay. The 50% inhibitory concentration (IC(50)) for the individual compounds were derived by interpolate plot analysis of the logarithmic scalar concentration curve after a 48 h exposure. HCC1937 cells were significantly (P<0.005) more sensitive to cisplatin (CDDP) (IC(50) : 30-40 microM) compared with MCF-7 (IC(50) : 60-70 microM) and MDA-MB231 (IC(50) : 90-100 microM) cells. On the other hand, BRCA1-defective breast cancer cells were significantly less sensitive to doxorubicin (Dox) (IC(50) : 45-50 microM) compared with MCF-7 (IC(50) : 1-5 microM) and MDA-MB231 (IC(50) : 5-10 microM) (P<0.02), as well as to paclitaxel (Tax) (IC(50) : >2 microM for HCC1937, 0.1-0.2 microM for MCF-7 and 0.01-0.02 microM for MDA-MB231) (P<0.001). Full-length BRCA1 cDNA transfection of BRCA1-defective HCC1937 cells led to the reconstituted expression of BRCA1 protein in HCC1937/(WT)BRCA1-derived cell clone, but did not reduce tumour cell growth in soft agar. BRCA1 reconstitution reverted the hypersensitivity to CDDP (P<0.02), and restored the sensitivity to Dox (P<0.05) and Tax (P<0.001), compared with parental HCC1937 cells. Taken together, our findings suggest a specific chemosensitivity profile of BRCA1-defective cells in vitro, which is dependent on BRCA1 protein expression, and suggest prospective preclinical and clinical investigation for the development of tailored therapeutical approaches in this setting.


Assuntos
Antineoplásicos/toxicidade , Proteína BRCA1/deficiência , Proteína BRCA1/genética , Apoptose/efeitos dos fármacos , Neoplasias da Mama/genética , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/toxicidade , Feminino , Humanos , Paclitaxel/toxicidade
20.
Cell Death Differ ; 10(2): 218-29, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12700650

RESUMO

The mechanisms of tumor cell resistance to interferon-alpha (IFNalpha) are at present mostly unsolved. We have previously demonstrated that IFNalpha induces apoptosis on epidermoid cancer cells and EGF antagonizes this effect. We have also found that IFNalpha-induced apoptosis depends upon activation of the NH(2)-terminal Jun kinase-1 (Jnk-1) and p(38) mitogen-activated protein kinase, and that these effects are also antagonized by EGF. At the same time, IFNalpha increases the expression and function of the epidermal growth factor receptor (EGF-R). Here we report that the apoptosis induced by IFNalpha occurs together with activation of caspases 3, 6 and 8 and that EGF also antagonizes this effect. On the basis of these results, we have hypothesized that the increased EGF-R expression and function could represent an inducible survival response that might protect tumor cells from apoptosis caused by IFNalpha via extracellular signal regulated kinase 1 and 2 (Erk-1/2) cascades. We have found an increased activity of Ras and Raf-1 in IFNalpha-treated cells. Moreover, IFNalpha induces a 50% increase of the phosphorylated isoforms and enzymatic activity of Erk-1/2. We have also demonstrated that the inhibition of Ras activity induced by the transfection of the dominant negative Ras plasmid RASN17 and the inhibition of Mek-1 with PD098059 strongly potentiates the apoptosis induced by IFNalpha. Moreover, the selective inhibition of this pathway abrogates the counteracting effect of EGF on the IFNalpha-induced apoptosis. All these findings suggest that epidermoid tumor cells counteract the IFNalpha-induced apoptosis through a survival pathway that involves the hyperactivation of the EGF-dependent Ras->Erk signalling. The selective targeting of this pathway appears to be a promising approach in order to enhance the antitumor activity of IFNalpha.


Assuntos
Apoptose/efeitos dos fármacos , Fator de Crescimento Epidérmico/metabolismo , Interferon-alfa/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas ras/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Caspases/metabolismo , Sobrevivência Celular , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/efeitos dos fármacos , Receptores ErbB/metabolismo , Flavonoides/farmacologia , Humanos , Interferon-alfa/metabolismo , Células KB , Proteína Quinase 1 Ativada por Mitógeno/efeitos dos fármacos , Proteína Quinase 3 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-raf/análise , Proteínas Proto-Oncogênicas c-raf/efeitos dos fármacos
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