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2.
Crit Rev Oncol Hematol ; 157: 103173, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33278677

RESUMO

BACKGROUND: immune checkpoint inhibitors(ICIs) have shown contradictory results in patients with advanced gastro-oesophageal junction/gastric cancer(GOJ/GC). AIM: to identify specific patient subgroups that would derive survival benefit from ICIs. METHODS: a subgroup meta-analysis of randomised clinical trials(RCTs) was carried out. RESULTS: four phase-III-RCTs were identified with data on the following variables: primary location(Gastric vs GOJ); age(≤ 65 vs >65); gender(male vs female); ECOG PS(0 vs 1); ethnicity (Asian vs non-Asian), histology(intestinal vs diffuse), PD-L1 expression(≥ 1% vs < 1%). PD-L1 positivity was significantly associated with survival benefit from ICIs (HR: 0.82, p 0.047), with a significant interaction between PD-L1 expression and ICI efficacy (interaction HR: 1.41, p 0.02). Numerically, the second most relevant interaction was ICI efficacy and gender, with ICI being more effective in males. CONCLUSION: The PD-L1 positive patient subgroup derives significant survival benefit from ICI in GOJ/GC, however other predictors are eagerly needed to further refine patient selection.


Assuntos
Adenocarcinoma , Neoplasias Gástricas , Adenocarcinoma/tratamento farmacológico , Junção Esofagogástrica , Feminino , Humanos , Inibidores de Checkpoint Imunológico , Masculino , Receptor de Morte Celular Programada 1 , Neoplasias Gástricas/tratamento farmacológico
5.
Crit Rev Oncol Hematol ; 111: 133-143, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28259288

RESUMO

Excision repair cross-complementation group 1 (ERCC1) is a key component in DNA repair mechanisms and may influence the tumor DNA-targeting effect of the chemotherapeutic agent oxaliplatin. Germline ERCC1 polymorphisms may alter the protein expression and published data on their predictive and prognostic value have so far been contradictory. In the present article we review available evidence on the clinical role and utility of ERCC1 polymorphisms and, in the absence of a 'perfect' trial, what we call the 'sliding doors' trial, we present the data of ERCC1 genotyping in our local patient population. We found a useful predictive value for oxaliplatin-induced risk of anemia.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/enzimologia , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/genética , Reparo do DNA , DNA de Neoplasias/genética , Proteínas de Ligação a DNA/química , Endonucleases/química , Feminino , Humanos , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Polimorfismo de Nucleotídeo Único , Prognóstico , Proteína de Replicação C/química , Proteína de Replicação C/genética , Fatores de Transcrição/química , Fatores de Transcrição/genética
6.
Eur Rev Med Pharmacol Sci ; 19(24): 4801-10, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26744872

RESUMO

OBJECTIVE: Mantle cell lymphoma (MCL) is a non-Hodgkin lymphoma (NHL) featured by participation of the lymph nodes, spleen, blood and bone marrow with a short remission period to standard therapies and a median overall survival of 4-5 years. PATIENTS AND METHODS: In this study, we compare the levels of bcl-1/JH fusion products detected by q-PCR in the concurrent peripheral blood (PB) and bone marrow (BM) aspirate samples from 7 patients with MCL. RESULTS: In patients with moderate to high levels of bcl-1/JH copies, the results of q-PCR analysis of PB and BM aspirate samples correlate well. In patients with high levels of bcl-1/JH copies, instead, PB levels are a good indication of tumor burden. Finally, in patients with low levels of bcl-1/JH copies, the t(11;14) may be detected by identification of neoplastic cells. CONCLUSIONS: Our data suggest that PB can be reliably used in place of BM aspirate both for detection of translocation status during minimal residual disease monitoring and for a possible molecular relapse, especially in those patients who have moderate to high levels of bcl-1/JH copies. If these results will be confirmed on a wider number of MCL patients, future study will be required to address the issue.


Assuntos
Genes bcl-1 , Linfoma de Célula do Manto/genética , Medula Óssea/patologia , Células da Medula Óssea , Transplante de Medula Óssea , Genes bcl-1/genética , Humanos , Linfoma de Célula do Manto/sangue , Recidiva Local de Neoplasia , Reação em Cadeia da Polimerase em Tempo Real , Indução de Remissão , Translocação Genética
7.
Cell Death Dis ; 4: e724, 2013 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-23846226

RESUMO

Sexual hormones, estrogens and androgens, determine biological response in a tissue- and gender-specific manner and have a pivotal role in endocrine-mediated tumorigenesis. In situ estrogen production by aromatase is a critical determinant for breast cancer growth and progression. On the contrary, clinical and in vitro studies indicate that androgens have a protective role in mammary carcinogenesis. Here, we demonstrated, in hormone-dependent breast cancer cells, the existence of a functional interplay between the androgen receptor (AR), the orphan nuclear receptor DAX-1 and the aromatase enzyme involved in the inhibition of the estrogen-dependent breast cancer cell proliferation exerted by androgen signaling. Indeed, our results revealed, in MCF-7 cells, that ligand-activated AR induces the expression of the orphan nuclear receptor DAX-1 by direct binding to a newly identified androgen-response-element within the DAX-1 proximal promoter. In turn, androgen-induced DAX-1 is recruited, in association with the corepressor N-CoR, within the SF-1/LRH-1 containing region of the aromatase promoter, thereby repressing aromatase expression and activity. In elucidating a novel mechanism by which androgens, through DAX-1, inhibit aromatase expression in breast cancer cell lines, these findings reinforce the theory of androgen- opposing estrogen-action, opening new avenues for therapeutic intervention in estrogen-dependent breast tumors.


Assuntos
Aromatase/metabolismo , Proliferação de Células , Receptor Nuclear Órfão DAX-1/genética , Estrogênios/fisiologia , Androgênios/farmacologia , Apoptose , Aromatase/genética , Sequência de Bases , Neoplasias da Mama , Receptor Nuclear Órfão DAX-1/metabolismo , Repressão Enzimática , Feminino , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Nandrolona/análogos & derivados , Nandrolona/farmacologia , Neoplasias Hormônio-Dependentes , Regiões Promotoras Genéticas , Receptores Androgênicos/metabolismo , Elementos de Resposta
8.
Transplant Proc ; 45(5): 1969-70, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23769085

RESUMO

BACKGROUND: Combined liver-kidney transplantation (LKT) is considered to be a safe procedure, but the appropriate immunosuppressive regimen is unclear. PATIENTS AND METHODS: Between January 1997 and October 2011, 55 patients were listed for LKT: 45 (82%) were effectively transplanted, 5 (9.2%) died whereon here the waiting list, 3 (5.5%) temporarily out of waiting list, 1 (1.8%) was on waiting list and 1 (1.8%) refused LKT. Five LKTs treated with cyclosporine (CyA) were excluded from the analysis. Mean recipient age was 50.32 ± 10.32 years (14-65), MELD score at time of LKT was 19.22 ± 4.69 (8-29), mean waiting list time was 8.14 ± 9.50 months (0.1-35.76), and follow-up, 4.09 ± 3.02 years (0.01-10.41). Main indications for LKT were policystic disease (n = 15; 37%), hepatitis virus C (HCV)-related cirrhosis (n = 9; 22%) metabolic disease (n = 5; 13%), hepatitis virus B (HBV) cirrhosis (n = 4; 10%), alcoholic cirrhosis (n = 4; 10%), and cholestatic disease (n = 3; 8%). Immunosuppressive regimen was based on tacrolimus and steroids in 40 cases with induction therapy with alemtuzumab (Campath; 0.3 mg/kg) in 13 of 40 instances cases administered on day 0 and day 7. RESULTS: Postoperative mortality was 2.5%. Acute cellular rejection episodes were biopsy-proven in 2 (5%) cases, post-LKT infections developed in 17 cases (42.5%), and de novo cancer developed in 3 (7.5%) cases. Similar 5-year overall survivals were obtained irrespective of the LKT indication: 100% in cholestatic and alcoholic cirrhosis patients, 86% in policystic disease, 75% in metabolic disease and HBV patients, and 66% in HCV cirrhosis. Overall survivals for the alemtuzumab vs without-induction therapy groups at 1, 3, and 5-years were 100%, 85.7%, and 85.7% vs 76%, 76%, and 70%, respectively (P = .04). CONCLUSION: An immunosuppressive regimen based on tacrolimus and steroids with induction therapy with alemtuzumab was safe, with excellent long-term results for combined LKT.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Transplante de Rim , Transplante de Fígado , Adolescente , Adulto , Idoso , Alemtuzumab , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Listas de Espera , Adulto Jovem
10.
Transplant Proc ; 40(6): 1814-5, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18675057

RESUMO

BACKGROUND: The use of the Model for End-stage Liver Disease (MELD) score to prioritize patients on liver waiting lists and to share organs among centers was effective according to US data, but few reports are available in Europe. MATERIALS AND METHODS: We evaluated the outcome of 887 patients listed between April 2004 and July 2006 in a common list by two transplant centers (University of Bologna [BO] and University of Modena [MO] ordered according to the MELD system. Patients with hepatocellular carcinoma had a score calculated according to their real MELD, tumor stage, and waiting time. RESULTS: Five hundred eighty-six (67%) patients were listed from BO and 291 (33%) from MO. The clinical features of recipients (sex, age, blood group, and real MELD) were comparable between centers. The number of liver transplantations performed was 307, and 273 (89%) recipients had a calculated MELD >or=20. Liver transplantations were equally distributed according to the number of patients listed: 215 out of 586 (36.7%) for BO and 92 out of 291 (31.6%) for MO. The median real MELD of patients transplanted was 20, and 246 out of 307 (80.1%) grafts transplanted were functioning. The dropouts from the list were 124 (14%), and 87 (70%) of these patients had a calculated MELD >or=20. CONCLUSION: The MELD system was effective to share livers among the two Italian centers. According to this policy, livers were allocated to the recipients with the highest probability of dropout and who had a satisfactory survival after liver transplantation.


Assuntos
Hepatectomia , Falência Hepática/cirurgia , Transplante de Fígado/estatística & dados numéricos , Coleta de Tecidos e Órgãos/métodos , Obtenção de Tecidos e Órgãos/métodos , Adolescente , Adulto , Idoso , Cadáver , Carcinoma Hepatocelular/cirurgia , Feminino , Humanos , Itália , Doadores Vivos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Alocação de Recursos/métodos , Doadores de Tecidos/estatística & dados numéricos , Resultado do Tratamento , Listas de Espera
11.
Ann Oncol ; 18 Suppl 6: vi81-5, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17591841

RESUMO

BACKGROUND: Insulin receptor substrate 1 (IRS-1) is a signaling molecule that exerts a key role in mediating cross talk between estrogen receptor alpha (ERalpha) and insulin-like growth factor 1 (IGF-1) in breast cancer cells. Previously, we demonstrated that a fraction of IRS-1 binds ERalpha, translocates to the nucleus, and modulates ERalpha-dependent transcription at estrogen response elements (ERE). Here, we studied structure-function relationships of the ERalpha:IRS-1 complex under IGF-1 and/or estradiol (E2) stimulation. MATERIALS AND METHODS: ERalpha and IRS-1 deletion mutants were used to analyze structural and functional ERalpha/IRS-1 interactions. IRS-1 binding to ERE and IRS-1 role in ERalpha-dependent ERE transcription was examined by chromatin immunoprecipitation and gene reporter analysis, respectively. The requirement for IRS-1 in ERalpha function was tested with RNAi technology. RESULTS: Nuclear translocation of IRS-1 was induced by E2, IGF-1, and a combination of both stimuli. ERalpha/IRS-1 binding was direct and involved the activation function-1 (AF-1)/DNA binding domain (DBD) region of ERalpha and two discrete regions of IRS-1 (the N-terminal pleckstrin homology domain and a region within the C-terminus). IRS-1 knock down abrogated IGF-1-dependent transcriptional activity of unliganded ERalpha, but induced the activity of liganded ERalpha. CONCLUSIONS: ERalpha/IRS-1 interactions are direct and involve the ERalpha AF-1/DBD domain and IRS-1 domains mapping within N- and C-terminus. IRS-1 may act as a repressor of liganded ERalpha and coactivator of unliganded ERalpha.


Assuntos
Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/fisiologia , Fosfoproteínas/fisiologia , Transporte Ativo do Núcleo Celular/genética , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Estradiol/fisiologia , Receptor alfa de Estrogênio/antagonistas & inibidores , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Proteínas Substratos do Receptor de Insulina , Fator de Crescimento Insulin-Like I/fisiologia , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/fisiologia , Fosfoproteínas/antagonistas & inibidores , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Ligação Proteica/genética , Estrutura Terciária de Proteína/genética , Receptor de Insulina/fisiologia , Receptores de Interferon/genética , Receptores de Interferon/metabolismo , Receptores de Interferon/fisiologia , Proteínas Repressoras/fisiologia , Relação Estrutura-Atividade
12.
Int J Biol Markers ; 22(1): 39-42, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17393360

RESUMO

The FHIT gene, a member of the histidine triad gene family, is a tumor suppressor gene exhibiting deletions in the majority of human cancers. Aberrant transcripts of this gene have been found in about 50% of esophageal, stomach and colon carcinomas. Little is known about the molecular mechanisms involved in malignant transformation of the lining cells of the anus. In this study FHIT gene expression was investigated in this particular kind of human cancer. FHIT expression was comparatively analyzed at the mRNA level, by RT-PCR, in squamous anal cancers, normal anal tissue and peripheral blood samples. cDNA analyses showed variability in FHIT transcripts, without apparent effects on the predicted amino acid sequence. These different FHIT mRNAs could represent transcripts from an alternative splicing event. Our data indicate that the FHIT mRNA detected in anal cancers and in normal samples is heterogeneous. Immunohistochemical data suggest that the Fhit protein is expressed only in a fraction of the tumor cells, while it is strongly expressed in the epithelial cells of glands of the normal anal mucosa. The absence or poor expression of the Fhit protein in anal cancers suggests a role for this tumor suppressor gene product, as a risk factor, in the onset of this human cancer, as reported before for other human gastrointestinal tumors.


Assuntos
Hidrolases Anidrido Ácido/biossíntese , Neoplasias do Ânus/metabolismo , Proteínas de Neoplasias/biossíntese , Neoplasias do Ânus/genética , Sequência de Bases , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Dados de Sequência Molecular , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Transplant Proc ; 38(5): 1477-80, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16797338

RESUMO

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLDs) are an uncommon but important cause of morbidity and mortality in solid organ transplant recipients. They are often the result of Epstein-Barr virus (EBV)-induced proliferation of B-lymphocytes in the setting of immunosuppression. PATIENTS AND METHODS: We retrospectively analyzed four cases of PTLD after liver transplantation. In all patients immunosuppression was reduced and anti-CD20 monoclonal antibody (rituximab) was administered. In two of four patients, EBV viral load was positive in the peripheral blood, and gancyclovir was therefore also prescribed. Chemotherapy (CHOP) was used as a rescue in the event of treatment failure. RESULTS: Even if no severe adverse events were observed during the treatment period, our treatment approach to PTLD was not effective, and only one patient out of four is still alive. CONCLUSIONS: Well-designed clinical trials are necessary to evaluate the role of this combined approach in the treatment of PTLD in liver transplant recipients.


Assuntos
Imunossupressores/efeitos adversos , Transplante de Fígado/imunologia , Transtornos Linfoproliferativos/induzido quimicamente , Idoso , Anticorpos/uso terapêutico , Antígenos CD20/imunologia , Ciclosporina/efeitos adversos , Infecções por Vírus Epstein-Barr/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/induzido quimicamente , Estudos Retrospectivos , Tacrolimo/efeitos adversos , Carga Viral
14.
J Mol Endocrinol ; 36(1): 91-105, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16461930

RESUMO

In the present study, the molecular mechanism underlying the up-regulatory effect of estradiol (E2) on mouse insulin receptor substrate-1 (IRS-1) promoter was investigated in CHO cells on which the same promoter had first been functionally characterized. The mouse IRS-1 promoter bears four consensus half Estrogen Responsive Elements (ERE) sequences and thirteen AP-1- and ten Sp1-binding elements. We performed molecular dissection of this promoter gene providing 3' different deleted constructs, containing the same AP-1 rich region with a progressively increased number of ERE half sites located downstream. None of these constructs was responsive to E2, while a downstream region (nt -1420 to -160) rich in GC elements was induced by E2. However, the latter region lost its intrinsic E2 responsiveness when the whole IRS-1 promoter was mutated for deletion in all four ERE half sites. Deletion analysis of the ERE half sites demonstrated that only ERE located at the position -1500 to -1495, close to the GC-rich region, was able to maintain the induced activatory effect of E2 on the IRS-1 gene. Electrophoretic mobility shift and chromatin immunoprecipitation assays identified the region containing the half ERE/Sp1 (nt -1500 to -1477) as the one conferring E2 responsiveness to the whole promoter. This effect occurs through the functional interaction between E2/ERalpha and Sp1.


Assuntos
Receptor alfa de Estrogênio/metabolismo , Fosfoproteínas/genética , Regiões Promotoras Genéticas , Fator de Transcrição Sp1/metabolismo , Animais , Sequência de Bases , Western Blotting , Células CHO , Linhagem Celular Tumoral , Cricetinae , Primers do DNA , Ensaio de Desvio de Mobilidade Eletroforética , Humanos , Proteínas Substratos do Receptor de Insulina , Camundongos , Mutagênese Sítio-Dirigida , Ligação Proteica
15.
Horm Metab Res ; 36(5): 336-40, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15156414

RESUMO

While obesity is a known risk factor for postmenopausal breast cancer, the molecular mechanisms involved are unclear. Systemic levels of leptin, the product of the ob (obesity) gene, are increased in obese individuals (body mass index, BMI, over 25) and are higher in women than men. Leptin has been found to stimulate the growth of breast cancer cells in vitro. Our goal was to determine whether leptin was 1) present in nipple aspirate fluid (NAF), and 2) whether NAF leptin levels were associated with a) levels in serum, b) obesity, and c) breast cancer. We collected and evaluated NAF specimens from 83 subjects and serum specimens from 49 subjects. NAF leptin was detectable in 16/41 (39 %) of premenopausal and 21/42 (50 %) postmenopausal subjects. NAF leptin was significantly lower (p = 0.042) in premenopausal than postmenopausal women with a BMI < 25, but not in those with a higher BMI. NAF leptin was significantly associated with BMI in premenopausal (p = 0.011) but not in postmenopausal women. Serum leptin was associated with BMI in both premenopausal and postmenopausal women (p = 0.0001 for both). NAF and serum leptin were associated in premenopausal (p = 0.02) but not postmenopausal women. Neither NAF nor serum leptin was associated with premenopausal or postmenopausal breast cancer. Our findings include that 1) leptin is present in the breast and detectable in a subset of NAF samples, 2) NAF leptin in premenopausal but not postmenopausal women parallels serum leptin levels, and 3) neither NAF nor serum levels of leptin were associated with premenopausal or postmenopausal breast cancer.


Assuntos
Neoplasias da Mama/epidemiologia , Leptina/sangue , Leptina/metabolismo , Mamilos/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Índice de Massa Corporal , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa , Pré-Menopausa
16.
Ann Ital Chir ; 74(2): 165-8, 2003.
Artigo em Italiano | MEDLINE | ID: mdl-14577112

RESUMO

Spigelian hernia, or ventro-lateral hernia is a rare clinical condition, it represents about 1.5% of hernial formation cases of the abdominal wall. It is localised laterally to the rectus muscle and emerges from the semilunar arch. The line, which joins the IX rib to the pubic tubercle, defines the limit between muscular and aponeurotic portion of trasversus abdominis muscle. Diagnosis often results misunderstood. As a matter of fact, this hernia has typically an intraparietal localization and the clinical picture seldom presents characteristic signs. The hernial sac and its content can be appreciated subcutaneously in only 2% of cases. It is estimated that about 50% of patients affected by this condition have a certain diagnosis before surgery. The early clinical signs are generally aspecific and deceitful, represented by oppressive grief and rarely by an abdominal wall tumor; it occurs that it starts with a complication: intestinal occlusion (23%), subocclusion (8%), strangulation (20%, but some authors report percentage up to 50%). We report 5 cases who came to our observation during the last 7 years; all patients underwent elective surgery, and specifically 3 patients in day surgery. Starting from the discussion of these cases, we review anatomy, etiology, clinical nature, instrumental investigation and surgical technique of this rare kind of hernia, comparing our experience to literature reported case histories.


Assuntos
Hérnia Ventral/cirurgia , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Hérnia Ventral/diagnóstico , Hérnia Ventral/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Reto do Abdome/patologia , Reto do Abdome/cirurgia , Estudos Retrospectivos
18.
Br J Cancer ; 86(6): 917-23, 2002 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-11953824

RESUMO

We used subtractive library screening to identify the changes that occur in gene expression during thyroid cell neoplastic transformation. Complementary DNA from normal thyroid cells (HTC 2) was subtracted from a complementary DNA library constructed from a human thyroid papillary carcinoma cell line. The library was screened for genes upregulated in human thyroid papillary carcinoma cell line cells, and several cDNA clones were isolated. One of these clones has a sirtuin core and high homology with the human silent information regulator protein family. This clone, designated "SIR-T8", was overexpressed in human thyroid carcinoma cell lines and tissues, but not in adenomas. The human SIR-T8 protein has a molecular weight of 39 kDa and is primarily located in the cytoplasm under the nuclear membrane. The SIR-T8 gene is located on chromosome 17q25-1.


Assuntos
Histona Desacetilases/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae , Telomerase/genética , Neoplasias da Glândula Tireoide/genética , Transativadores/genética , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Expressão Gênica , Biblioteca Gênica , Humanos , Dados de Sequência Molecular , Sirtuína 1 , Sirtuína 2 , Sirtuínas , Células Tumorais Cultivadas
19.
Cancer Res ; 61(18): 6747-54, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11559546

RESUMO

The insulin-like growth factor I receptor (IGF-IR) is a ubiquitous and multifunctional tyrosine kinase that has been implicated in breast cancer development. In estrogen receptor (ER)-positive breast tumors, the levels of the IGF-IR and its substrate, insulin-receptor substrate 1 (IRS-1), are often elevated, and these characteristics have been linked with increased radioresistance and cancer recurrence. In vitro, activation of the IGF-IR/IRS-1 pathway in ER-positive cells improves growth and counteracts apoptosis induced by anticancer treatments. The function of the IGF-IR in hormone-independent breast cancer is not clear. ER-negative breast cancer cells often express low levels of the IGF-IR and fail to respond to IGF-I with mitogenesis. On the other hand, anti-IGF-IR strategies effectively reduced metastatic potential of different ER-negative cell lines, suggesting a role of this receptor in late stages of the disease. Here we examined IGF-IR signaling and function in ER-negative MDA-MB-231 breast cancer cells and their IGF-IR-overexpressing derivatives. We demonstrated that IGF-I acts as a chemoattractant for these cells. The extent of IGF-I-induced migration reflected IGF-IR levels and required the activation of phosphatidylinositol 3-kinase (PI-3K) and p38 kinases. The same pathways promoted IGF-I-dependent motility in ER-positive MCF-7 cells. In contrast with the positive effects on cell migration, IGF-I was unable to stimulate growth or improve survival in MDA-MB-231 cells, whereas it induced mitogenic and antiapoptotic effects in MCF-7 cells. Moreover, IGF-I partially restored growth in ER-positive cells treated with PI-3K and ERK1/ERK2 inhibitors, whereas it had no protective effects in ER-negative cells. The impaired IGF-I growth response of ER-negative cells was not caused by a low IGF-IR expression, defective IGF-IR tyrosine phosphorylation, or improper tyrosine phosphorylation of IRS-1. Also, the acute (15-min) IGF-I activation of PI-3 and Akt kinases was similar in ER-negative and ER-positive cells. However, a chronic (2-day) IGF-I exposure induced the PI-3K/Akt pathway only in MCF-7 cells. The reactivation of this pathway in ER-negative cells by overexpression of constitutively active Akt mutants was not sufficient to significantly improve proliferation or survival (with or without IGF-I), which indicated that other pathways are also required to support these functions. Our results suggest that in breast cancer cells, IGF-IR can control nonmitogenic processes regardless of the ER status, whereas IGF-IR growth-related functions may depend on ER expression.


Assuntos
Neoplasias da Mama/patologia , Proteínas Serina-Treonina Quinases , Receptor IGF Tipo 1/fisiologia , Receptores de Estrogênio/fisiologia , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Ativação Enzimática , Humanos , Fator de Crescimento Insulin-Like I/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Receptor IGF Tipo 1/biossíntese , Receptor IGF Tipo 1/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Transfecção , Células Tumorais Cultivadas , Proteínas Quinases p38 Ativadas por Mitógeno
20.
J Biol Chem ; 276(43): 39892-7, 2001 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-11518717

RESUMO

Hyperactivation of the insulin-like growth factor I receptor (IGF-IR) contributes to primary breast cancer development, but the role of the IGF-IR in tumor metastasis is unclear. Here we studied the effects of the IGF-IR on intercellular connections mediated by the major epithelial adhesion protein, E-cadherin (E-cad). We found that IGF-IR overexpression markedly stimulated aggregation in E-cad-positive MCF-7 breast cancer cells, but not in E-cad-negative MDA-MB-231 cells. However, when the IGF-IR and E-cad were co-expressed in MDA-MB-231 cells, cell-cell adhesion was substantially increased. The IGF-IR-dependent cell-cell adhesion of MCF-7 cells was not related to altered expression of E-cad or alpha-, beta-, or gamma-catenins but coincided with the up-regulation of another element of the E-cad complex, zonula occludens-1 (ZO-1). ZO-1 expression (mRNA and protein) was induced by IGF-I and was blocked in MCF-7 cells with a tyrosine kinase-defective IGF-IR mutant. By co-immunoprecipitation, we found that ZO-1 associates with the E-cad complex and the IGF-IR. High levels of ZO-1 coincided with an increased IGF-IR/alpha-catenin/ZO-1-binding and improved ZO-1/actin association, whereas down-regulation of ZO-1 by the expression of an anti-ZO-1 RNA inhibited IGF-IR-dependent cell-cell adhesion. The results suggested that one of the mechanisms by which the activated IGF-IR regulates E-cad-mediated cell-cell adhesion is overexpression of ZO-1 and the resulting stronger connections between the E-cad complex and the actin cytoskeleton. We hypothesize that in E-cad-positive cells, the IGF-IR may produce antimetastatic effects.


Assuntos
Neoplasias da Mama/metabolismo , Caderinas/metabolismo , Junções Intercelulares , Proteínas de Membrana/metabolismo , Fosfoproteínas/metabolismo , Receptor IGF Tipo 1/metabolismo , Adesão Celular , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas de Membrana/genética , Modelos Biológicos , Fosfoproteínas/genética , Ligação Proteica , Proteína da Zônula de Oclusão-1
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