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1.
Health Econ ; 32(1): 175-193, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36221234

RESUMO

Intimate Partner Violence (IPV) continues to be a major public health concern that can both respond to economic policies and affect economic outcomes. Few studies regarding IPV, however, take a gender inclusive approach towards its identification. Using a sample of both men and women from rural Kenya, we are the first, to our knowledge, to conduct a list experiment with cohabiting married couples to identify the prevalence of physical violence on both men and women. We find that 14 percent of respondents agree with the statement "my spouse regularly hits me". In contrast to other survey evidence that uses direct elicitation, we find no differences in the prevalence of male-to-female and female-to-male violence. We provide supporting evidence that bidirectional IPV accounts for the lack of gender differences. A complete understanding of the typology of IPV can be crucial for policies seeking IPV reduction.


Assuntos
Violência por Parceiro Íntimo , Feminino , Masculino , Humanos , Quênia/epidemiologia , Fatores de Risco , Prevalência , Violência , Parceiros Sexuais
2.
Int J Mol Sci ; 24(1)2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36614121

RESUMO

Although the overall survival of advanced soft-tissue sarcoma (STS) patients has increased in recent years, the median progression-free survival is lower than 5 months, meaning that there is an unmet need in this population. Among second-line treatments for advanced STS, eribulin is an anti-microtubule agent that has been approved for liposarcoma. Here, we tested the combination of eribulin with gemcitabine in preclinical models of L-sarcoma. The effect in cell viability was measured by MTS and clonogenic assay. Cell cycle profiling was studied by flow cytometry, while apoptosis was measured by flow cytometry and Western blotting. The activity of eribulin plus gemcitabine was evaluated in in vivo patient-derived xenograft (PDX) models. In L-sarcoma cell lines, eribulin plus gemcitabine showed to be synergistic, increasing the number of hypodiploid events (increased subG1 population) and the accumulation of DNA damage. In in vivo PDX models of L-sarcomas, eribulin combined with gemcitabine was a viable scheme, delaying tumour growth after one cycle of treatment, being more effective in leiomyosarcoma. The combination of eribulin and gemcitabine was synergistic in L-sarcoma cultures and it showed to be active in in vivo studies. This combination deserves further exploration in the clinical context.


Assuntos
Leiomiossarcoma , Sarcoma , Neoplasias de Tecidos Moles , Humanos , Gencitabina , Sarcoma/patologia , Leiomiossarcoma/patologia , Furanos/farmacologia , Furanos/uso terapêutico , Cetonas/farmacologia , Cetonas/uso terapêutico , Neoplasias de Tecidos Moles/patologia
3.
Cancers (Basel) ; 12(6)2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32549380

RESUMO

Conflicting results have been reported regarding the prevalence of screen-detected human epidermal growth factor receptor 2 (HER2)-positive breast carcinomas and non-screen detected HER2-positive breast carcinomas. To address this issue, we evaluated the prevalence of HER2-positive breast carcinomas in two independent regional screening programs in Spain. The clinicopathologic and immunohistochemical characteristics of 479 (306 and 173) screen-detected breast carcinomas and 819 (479 and 340) non-screen-detected breast carcinomas diagnosed in women between 50 and 69-year-olds were compared. The prevalence of HER2-positive breast carcinomas was 8.8% and 6.4% in the two series of screen-detected tumors, compared with 16.4% and 13% in non-screen-detected carcinomas. These differences were statistically significant. This lower prevalence of HER2-positive in-screen-detected breast carcinomas was observed in both hormone receptor positive (luminal HER2) and hormone-receptor-negative (HER2 enriched) tumors. In addition, a lower prevalence of triple-negative and a higher prevalence of luminal-A breast carcinomas was observed in screen-detected tumors. Moreover, a literature review pointed out important differences in subrogate molecular types in screen-detected breast carcinomas among reported series, mainly due to study design, technical issues and racial differences.

4.
Mol Cancer Ther ; 15(7): 1713-25, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27196755

RESUMO

Prostate cancer is the leading cause of cancer-related death among men in developed countries. Although castration therapy is initially effective, prostate cancers progress to hormone-refractory disease and in this case taxane-based chemotherapy is widely used. Castration-resistant prostate cancer cells often develop resistance to chemotherapy agents and the search for new therapeutic strategies is necessary. In this article, we demonstrate that PKCδ silencing favors mitotic arrest after paclitaxel treatment in PC3 and LNCaP cells; however, this is associated with resistance to paclitaxel-induced apoptosis. In prostate cancer cells, PKCδ seems to exert a proapoptotic role, acting as a negative regulator of the canonical Wnt/ß-catenin pathway. PKCδ silencing induces activation of Wnt/ß-catenin pathway and the expression of its target genes, including Aurora kinase A, which is involved in activation of Akt and both factors play a key role in GSK3ß inactivation and consequently in the stabilization of ß-catenin and antiapoptotic protein Mcl-1. We also show that combined treatments with paclitaxel and Wnt/ß-catenin or Akt inhibitors improve the apoptotic response to paclitaxel, even in the absence of PKCδ. Finally, we observe that high Gleason score prostate tumors lose PKCδ expression and this correlates with higher activation of ß-catenin, inactivation of GSK3ß, and higher levels of Aurora kinase A and Mcl-1 proteins. These findings suggest that targeting Wnt/ß-catenin or Akt pathways may increase the efficacy of taxane chemotherapy in advanced human prostate cancers that have lost PKCδ expression. Mol Cancer Ther; 15(7); 1713-25. ©2016 AACR.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Paclitaxel/farmacologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Proteína Quinase C-delta/deficiência , Via de Sinalização Wnt/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Apoptose/genética , Aurora Quinase A/genética , Aurora Quinase A/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Cromonas/farmacologia , Expressão Gênica , Inativação Gênica , Humanos , Masculino , Mitose/efeitos dos fármacos , Mitose/genética , Modelos Biológicos , Morfolinas/farmacologia , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , beta Catenina/metabolismo
5.
Histopathology ; 69(2): 239-49, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26708058

RESUMO

AIMS: Neoadjuvant therapy is used in many patients with breast cancer before surgery, with the aim of reducing the tumour size, allowing conservative resections. Sentinel node biopsy is a conservative procedure for handling the axilla in breast cancer; however, the use of this technique after neoadjuvant treatment is under discussion. For sentinel node assay, methods based on the detection of cytokeratin 19 (CK19) mRNA, such as one-step nucleic acid amplification (OSNA), are available. However, if systemic therapy could alter protein expression, then CK19 would not be a good target for analysing these nodes. The aim of this study was to evaluate the immunohistochemical expression of CK19 within different cancer types, and to compare its expression in breast tumours and axillary nodes before and after treatment. METHODS AND RESULTS: CK19 immunostaining was studied in 162 tumour and node samples before and after treatment. Statistical studies using the McNemar test and chi-square test were performed. CK19 expression was found in 155 cases. We compared CK19 expression in tumour and node biopsies before and after treatment, and we found a lack of significant CK19 expression changes. CONCLUSIONS: Our study has confirmed the preservation of CK19 protein expression in breast cancer cells after neoadjuvant therapy. On the basis of these results, quantification-based methods such as the OSNA CK19 assay, could be an accurate tool with which to analyse the sentinel nodes, regardless of whether they had been obtained before or after treatment.


Assuntos
Neoplasias da Mama/metabolismo , Queratina-19/metabolismo , Técnicas de Amplificação de Ácido Nucleico/métodos , Idoso , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Queratina-19/genética , Excisão de Linfonodo , Linfonodos/patologia , Metástase Linfática , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estadiamento de Neoplasias , Biópsia de Linfonodo Sentinela
6.
Mol Cancer Ther ; 13(10): 2372-83, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25122070

RESUMO

PTTG1 protein, the human securin, has a central role in sister chromatid separation during mitosis, and its altered expression has been reported in many tumor types. Paclitaxel is a widely used chemotherapeutic drug, whose mechanism of action is related to its ability to arrest cells in mitosis and the subsequent induction of the intrinsic apoptotic pathway. By using two prostate cancer cell lines with different responses to paclitaxel treatment, we have identified two situations in which PTTG1 influences cell fate differentially. In slippage-prone PC3 cells, both PTTG1 downregulation and overexpression induce an increase in mitotic cells that is associated with diminished apoptosis after paclitaxel treatment. In LNCaP cells, however, PTTG1 downregulation prevents mitotic entry and, subsequently, inhibits mitosis-associated, paclitaxel-induced apoptosis. In contrast, PTTG1 overexpression induces an increase in mitotic cells and apoptosis after paclitaxel treatment. We have also identified a role for Mcl-1 protein in preventing apoptosis during mitosis in PC3 cells, as simultaneous PTTG1 and Mcl-1 silencing enhances mitosis-associated apoptosis after paclitaxel treatment. The finding that a more efficient mitotic arrest alone in PC3 cells is not enough to increase apoptosis was also confirmed with the observation that a selected paclitaxel-resistant PC3 cell line showed an apoptosis-resistant phenotype associated with increased mitosis upon paclitaxel treatment. These findings could contribute to identify putative responsive and nonresponsive cells and help us to approach incomplete responses to paclitaxel in the clinical setting.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Paclitaxel/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Securina/biossíntese , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Regulação para Baixo , Inativação Gênica , Humanos , Masculino , Mitose/efeitos dos fármacos , Mitose/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/biossíntese , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Securina/genética , Transfecção
7.
Eur J Cancer ; 49(2): 500-10, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22819078

RESUMO

Pituitary tumour transforming gene (pttg1) encodes Securin, a protein involved in the inhibition of sister chromatid separation binding to Separase until the onset of anaphase. Separase is a cysteine-protease that degrades cohesin to segregate the sister chromatids to opposite poles of the cell. The amount of Securin is strongly regulated because it should allow Separase activation when it is degraded by the anaphase promoting complex/cyclosome, should arrest the cell cycle after DNA damage, when it is degraded through SKP1-CUL1-ßTrCP ubiquitin ligase, and its overexpression induces tumour formation and correlates with metastasis in multiple tumours. Securin is a phosphoprotein that contains 32 potentially phosphorylatable residues. We mutated and analysed most of them, and found a single mutant, hSecT60A, that showed enhanced oncogenic properties. Our fluorescence activated cell sorting analysis, fluorescence in situ hybridisation assays, tumour cell migration and invasion experiments and gene expression by microarrays analysis clearly involved hSecT60A in chromosomal instability and cell invasion. These results show, for the first time, that a single mutation in pttg1 is sufficient to trigger the oncogenic properties of Securin. The finding of this point mutation in patients might be used as an effective strategy for early detection of cancer.


Assuntos
Transformação Celular Neoplásica/genética , Instabilidade Cromossômica , Proteínas de Neoplasias/genética , Neoplasias/genética , Mutação Puntual , Animais , Células COS , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Chlorocebus aethiops , Expressão Gênica , Células HCT116 , Células HeLa , Humanos , Análise em Microsséries , Invasividade Neoplásica , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Securina , Treonina/genética , Transfecção
8.
Clin Exp Metastasis ; 29(4): 349-58, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22274591

RESUMO

PTPL1, a non-receptor type protein tyrosine phosphatase, has been involved in the regulation of apoptosis and invasiveness of various tumour cell types, but its role in prostate cancer remained to be investigated. We report here that downregulation of PTPL1 by small interfering RNA in PC3 cells decreases cell proliferation and concomitantly reduces the expression of cell cycle-related proteins such as cyclins E and B1, PCNA, PTTG1 and phospho-histone H3. PTPL1 downregulation also increases the invasion ability of PC3 cells through Matrigel coated membranes. cDNA array of PTPL1-silenced PC3 cells versus control cells showed an upregulation of invasion-related genes such as uPA, uPAR, tPA, PAI-1, integrin α6 and osteopontin. This increased expression was also confirmed in PTPL1-silenced DU145 prostate cancer cells by quantitative real time PCR and western blot. These findings suggest that PTPL1 is an important mediator of central cellular processes such as proliferation and invasion.


Assuntos
Ciclo Celular , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteína Tirosina Fosfatase não Receptora Tipo 13/metabolismo , Western Blotting , Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica , Humanos , Integrina alfa6/genética , Integrina alfa6/metabolismo , Masculino , Invasividade Neoplásica/genética , Osteopontina/genética , Osteopontina/metabolismo , Fenótipo , Inibidor 1 de Ativador de Plasminogênio/genética , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Neoplasias da Próstata/enzimologia , RNA Interferente Pequeno/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Ativador de Plasminogênio Tipo Uroquinase/genética , Receptores de Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Ativador de Plasminogênio Tecidual/genética , Ativador de Plasminogênio Tecidual/metabolismo , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacos , Ativador de Plasminogênio Tipo Uroquinase/genética , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
9.
Breast Cancer Res Treat ; 133(3): 917-28, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22076480

RESUMO

Taxanes are being used for the treatment of breast cancer. However, cancer cells frequently develop resistance to these drugs with the subsequent recurrence of the tumor. MDA-MB-231 and T-47D breast cancer cell lines were used to assess the effect of paclitaxel treatment on apoptosis and cell cycle, the possible mechanisms of paclitaxel resistance as well as the enhancement of paclitaxel-induced apoptosis based on its combination with phenylethyl isothiocyanate (PEITC). T-47D cells undergo apoptosis in response to paclitaxel treatment. The induction of apoptosis was associated with a robust mitotic arrest and the disruption of Bcl-xL/Bak interaction. By contrary, MDA-MB-231 cells were insensitive to paclitaxel-induced apoptosis and this was associated with a high percentage of cells that slip out of paclitaxel-imposed mitotic arrest and also with the maintenance of Bcl-xL/Bak interaction. The sequential treatment of MDA-MB-231 cells with PEITC followed by paclitaxel inhibited the slippage induced by paclitaxel and increased the apoptosis induction achieved with any of the drugs alone. In breast cancer tissues, high Bcl-xL expression was correlated with a shorter time of disease-free survival in patients treated with a chemotherapeutic regimen that contains paclitaxel, in a statistically significant way. Thus, resistance to paclitaxel in MDA-MB-231 cells is related to the inability to disrupt the Bcl-xL/Bak interaction and increased slippage. In this context, the combination of a drug that induces a strong mitotic arrest, such as paclitaxel, with another that inhibits slippage, such as PEITC, translates into increased apoptotic induction.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/metabolismo , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Paclitaxel/farmacologia , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína bcl-X/metabolismo , Antineoplásicos Fitogênicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Linhagem Celular Tumoral , Feminino , Humanos , Isotiocianatos/farmacologia , Paclitaxel/uso terapêutico , Ligação Proteica
10.
Urology ; 76(4): 1017.e1-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20708221

RESUMO

OBJECTIVES: To investigate the expression of Hsp60 protein in prostate cancer biopsy samples, and its association with prognostic clinical parameters and hormone resistance and survival. Molecular chaperones are involved in protein folding, protein degradation, and protein trafficking among subcellular compartments. METHODS: We selected 107 patients with localized and locally advanced prostate cancer at our hospital from 1999 through 2004. We performed an analysis by western blot and immunohistochemistry on paraffin-embedded tissue sections. Clinical data were used to determine associations between immunohistochemical expression of Hsp60 and tumor behavior. RESULTS: The expression level of Hsp60 was significantly increased in tumors with high Gleason score (P < .001). Hsp60 expression was also significantly associated with initial serum PSA levels (P < .01) and with the presence of lymph node metastasis (P < .003). In 50 locally advanced cancers treated by androgen ablation we found an association between high Hsp60-expressing tumors and an early onset of hormone refractory disease (P < .02) and reduced cancer-specific survival (P < .05). CONCLUSIONS: Hsp60 protein is overexpressed in poorly differentiated prostate cancers. Hsp60 expression is strongly associated with prognostic clinical parameters, such as Gleason score, initial serum PSA levels, and lymph node metastasis and with the onset of hormone-refractory disease and reduced cancer-specific survival. Identification of such markers could be of relevance in the clinical management of prostate cancer.


Assuntos
Adenocarcinoma/química , Antineoplásicos Hormonais/uso terapêutico , Biomarcadores Tumorais/análise , Chaperonina 60/análise , Resistencia a Medicamentos Antineoplásicos , Proteínas de Neoplasias/análise , Neoplasias da Próstata/química , Adenocarcinoma/sangue , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Androgênios , Antineoplásicos Hormonais/farmacologia , Diferenciação Celular , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Metástase Linfática , Masculino , Neoplasias Hormônio-Dependentes/química , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Neoplasias Hormônio-Dependentes/patologia , Modelos de Riscos Proporcionais , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Análise de Sobrevida
11.
BMC Cancer ; 8: 110, 2008 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-18426563

RESUMO

BACKGROUND: On its physiological cellular context, PTTG1 controls sister chromatid segregation during mitosis. Within its crosstalk to the cellular arrest machinery, relies a checkpoint of integrity for which gained the over name of securin. PTTG1 was found to promote malignant transformation in 3T3 fibroblasts, and further found to be overexpressed in different tumor types. More recently, PTTG1 has been also related to different processes such as DNA repair and found to trans-activate different cellular pathways involving c-myc, bax or p53, among others. PTTG1 over-expression has been correlated to a worse prognosis in thyroid, lung, colorectal cancer patients, and it can not be excluded that this effect may also occur in other tumor types. Despite the clinical relevance and the increasing molecular characterization of PTTG1, the reason for its up-regulation remains unclear. METHOD: We analysed PTTG1 differential expression in PC-3, DU-145 and LNCaP tumor cell lines, cultured in the presence of the methyl-transferase inhibitor 5-Aza-2'-deoxycytidine. We also tested whether the CpG island mapping PTTG1 proximal promoter evidenced a differential methylation pattern in differentiated thyroid cancer biopsies concordant to their PTTG1 immunohistochemistry status. Finally, we performed whole-genome LOH studies using Affymetix 50 K microarray technology and FRET analysis to search for allelic imbalances comprising the PTTG1 locus. CONCLUSION: Our data suggest that neither methylation alterations nor LOH are involved in PTTG1 over-expression. These data, together with those previously reported, point towards a post-transcriptional level of misregulation associated to PTTG1 over-expression.


Assuntos
Metilação de DNA , Epigênese Genética/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Proteínas de Neoplasias/metabolismo , Carcinoma/metabolismo , Técnicas de Cultura de Células , Linhagem Celular Tumoral/metabolismo , Genótipo , Humanos , Masculino , Proteínas de Neoplasias/genética , Neoplasias da Próstata/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Securina , Neoplasias da Glândula Tireoide/metabolismo , Regulação para Cima
12.
Clin Endocrinol (Oxf) ; 68(2): 190-7, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17803695

RESUMO

OBJECTIVE: The Bcl-2 family proteins are essential mediators in the apoptotic process. Our aim was to investigate whether anti-apoptotic Bcl-xL and pro-apoptotic Bax were over-expressed in a large series of differentiated thyroid carcinomas (DTC) and to study their association with tumour presentation at diagnosis and prognosis. DESIGN AND PATIENTS: We examined the immunohistochemical expression of Bcl-xL and Bax in benign nodular thyroid disease (BNTD) and DTC and their association with clinicopathological parameters. Thyroid tissue samples were collected from an unselected series of patients undergoing surgical resection for DTC (n = 74) or BNTD (n = 15). RESULTS: Among DTC cases, expression of Bcl-xL was found to be high in 43.2% and low or absent in 56.8%. Expression of Bax was high in 75.7% and low or absent in 24.3%. Non-neoplastic thyroid tissue was largely unstained for both proteins. Among BNTD cases, expression of Bcl-xL was high in 13.3% and low or absent in 86.6%. Expression of Bax was high in 14.3% and low or absent in 86.6%. A significant association was found between Bcl-xL expression and the presence of high-risk histological subtype (P < 0.05), and regional lymph node (P < 0.01) and distant metastases (P < 0.01). The association between high Bcl-xL expression levels and a longer time of persistent disease after radioiodine ablation was also significant (P < 0.01). Bcl-xL expression was confirmed as an independent prognostic factor for persistent disease in DTC (relative risk, 2.5; 95% confidence interval, 1.1-5.9; P < 0.05). CONCLUSIONS: Immunohistochemical expression of Bcl-xL might be a valuable tool in the prediction of tumour aggressiveness in DTC.


Assuntos
Neoplasias da Glândula Tireoide/metabolismo , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismo , Western Blotting , Humanos , Imuno-Histoquímica , Doenças da Glândula Tireoide/metabolismo , Glândula Tireoide/metabolismo , Glândula Tireoide/patologia
13.
Endocrinology ; 147(10): 4960-7, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16794010

RESUMO

Androgen-sensitive prostate cancer cells turn androgen resistant through complex mechanisms that involve dysregulation of apoptosis. We investigated the role of antiapoptotic Bcl-xL in the progression of prostate cancer as well as the interactions of Bcl-xL with proapoptotic Bax and Bak in androgen-dependent and -independent prostate cancer cells. Immunohistochemical analysis was used to study the expression of Bcl-xL in a series of 139 prostate carcinomas and its association with Gleason grade and time to hormone resistance. Expression of Bcl-xL was more abundant in prostate carcinomas of higher Gleason grades and significantly associated with the onset of hormone-refractory disease. In vivo interactions of Bcl-xL with Bax or Bak in untreated and camptothecin-treated LNCaP and PC3 cells were investigated by means of coimmunoprecipitation. In the absence of any stimuli, Bcl-xL interacts with Bax and Bak in androgen-independent PC3 cells but only with Bak in androgen-dependent LNCaP cells. Interactions of Bcl-xL with Bax and Bak were also evidenced in lysates from high-grade prostate cancer tissues. In LNCaP cells treated with camptothecin, an inhibitor of topoisomerase I, the interaction between Bcl-xL and Bak was absent after 36 h, Bcl-xL decreased gradually and Bak increased coincidentally with the progress of apoptosis. These results support a model in which Bcl-xL would exert an inhibitory effect over Bak via heterodimerization. We propose that these interactions may provide mechanisms for suppressing the activity of proapoptotic Bax and Bak in prostate cancer cells and that Bcl-xL expression contributes to androgen resistance and progression of prostate cancer.


Assuntos
Antineoplásicos Hormonais/farmacologia , Apoptose/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias da Próstata/genética , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína bcl-X/genética , Antineoplásicos Fitogênicos/farmacologia , Western Blotting , Camptotecina/farmacologia , Linhagem Celular Tumoral , Humanos , Imuno-Histoquímica , Imunoprecipitação , Masculino , Fenótipo , Proteína Killer-Antagonista Homóloga a bcl-2/biossíntese , Proteína X Associada a bcl-2/genética
14.
J Clin Endocrinol Metab ; 91(4): 1404-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16418208

RESUMO

CONTEXT: Human securin pituitary tumor-transforming gene (hPTTG) is overexpressed in a variety of primary neoplasias, including differentiated thyroid cancer (DTC). OBJECTIVE: The objective of this study was to examine the immunohistochemical expression of hPTTG in DTC and its association with known prognostic factors. DESIGN: hPTTG expression was analyzed by immunostaining on paraffin-embedded tissues. Clinical data were used to determine any associations between the expression of hPTTG and prognostic variables of DTC. A median follow-up of 43 months allowed us to analyze the persistence of disease and the response to radioiodine therapy. SETTING: The study was conducted at a tertiary university hospital. PATIENTS: Ninety-five patients undergoing surgical resection for DTC (n = 60) or benign nodular thyroid disease (n = 35) were studied. MAIN OUTCOME MEASURE: The main outcome measure was the association between hPTTG expression and prognostic factors in DTC. RESULTS: Among DTC cases, 21 (35%) had low and 39 (65%) had high hPTTG immunostaining. Adjacent nonneoplastic thyroid tissue was largely unstained. Among benign nodular thyroid disease cases, immunostaining was detected focally in eight (22.8%). A significant association was found between hPTTG expression and the presence of nodal (P < 0.01) or distant metastases (P < 0.05). A significant association with TNM was also found, because 83.3% of advanced TNM stages showed elevated hPTTG (P < 0.05). The association between hPTTG overexpression and decreased radioiodine uptake during follow-up was also significant (P < 0.05). The expression levels of hPTTG were confirmed as an independent prognostic factor for persistent disease (relative risk, 3.0; 95% confidence interval, 1.1-8.7; P < 0.05). CONCLUSIONS: Immunohistochemical analysis of hPTTG is of potential value in the determination of tumor aggressiveness in DTC.


Assuntos
Proteínas de Neoplasias/biossíntese , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Adenoma/genética , Adenoma/metabolismo , Adenoma/patologia , Idoso , Feminino , Regulação Neoplásica da Expressão Gênica/fisiologia , Bócio Nodular/genética , Bócio Nodular/metabolismo , Bócio Nodular/patologia , Humanos , Imuno-Histoquímica , Iodetos/metabolismo , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Inclusão em Parafina , Prognóstico , Modelos de Riscos Proporcionais , Securina , Neoplasias da Glândula Tireoide/metabolismo
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