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1.
Environ Res ; 204(Pt A): 111989, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34506784

RESUMO

Organophosphorus chlorpyrifos (CPF) is currently considered an endocrine disruptor (ED), as it can imitate hormone actions both in vitro and in vivo. We recently reported that CPF induces migration and invasion in 2D cultures and changes the expression of key molecular markers involved in epithelial mesenchymal transition in MCF-7 and MDA-MB-231 cell lines. In this study, we investigated whether CPF could behave as a predisposing factor for tumors to become more metastatic and aggressive using 3D culture models. In MCF-7 cells, 0.05 µM CPF induced an increase in the number and size of mammospheres via estrogen receptor alpha (ERα) and c-SRC. Furthermore, 0.05 µM CPF increased the area of spheroids generated from MCF-7 cells, induced invasion using both Matrigel® and type 1 collagen matrices, and increased cell migration capacity via ERα in this 3D model. In turn, 50 µM CPF increased cell migration capacity and invasion using type 1 collagen matrix. In monolayers, CPF increased the phosphorylation and membrane translocation of c-SRC at both concentrations assayed. CPF at 0.05 µM boosted p-AKT, p-GSK-3ß and p-P38. While p-AKT rose in a ERα-dependent way, p-GSK-3ß was dependent on ERα- and c-SRC, and p-P38 was only dependent on c-SRC. On the other hand, the increase in p-AKT and p-P38 induced by 50 µM CPF was dependent on the c-SRC pathway. We also observed that 0.05 µM CPF increased IGF-1R and IRS-1 expression and that 50 µM CPF induced IGF-1Rß phosphorylation. In the MDA-MB-231 cell line, 0.05 and 50 µM CPF increased p-c-SRC. Finally, p-AKT and p-GSK-3ß were also induced by CPF at 0.05 and 50 µM, and an increase in p-P38 was observed at 50 µM. Taken together, these data provide support for the notion that CPF may represent a risk factor for breast cancer development and progression.


Assuntos
Neoplasias da Mama , Clorpirifos , Disruptores Endócrinos , Linhagem Celular Tumoral , Proliferação de Células , Clorpirifos/toxicidade , Disruptores Endócrinos/toxicidade , Feminino , Glicogênio Sintase Quinase 3 beta , Humanos , Fenótipo , Fosforilação
2.
Ecotoxicol Environ Saf ; 205: 111312, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32956863

RESUMO

Chlorpyrifos (CPF) is one of the most frequently used pesticide in extensive agriculture around the world and can be incorporated by humans and animals with possible consequences on health. The effects of this pesticide on carcinogenesis are not clear and there is no consensus concerning the risks of this compound. In previous work, we demonstrated that CPF induces proliferation of breast cancer cells both in vivo and in vitro. In this work we investigate whether CPF promotes the epithelial-mesenchymal transition (EMT) in breast cancer cells. Herein, we demonstrate that 50 µM CFP induces invasion in MCF-7 and MDA-MB-231 cells. In addition, 0.05 and 50 µM CPF increases migration in both cell lines. In MCF-7 cells, 0.05 and 50 µM CPF increase the metalloprotease MMP2 expression and decrease E-Cadherin and ß-Catenin expression diminishing their membrane location. Furthermore, 50 µM CPF induces Vimentin expression and Slug nuclear translocation in MCF-7 cells. 0.05 and 50 µM CPF increase MMP2 gelatinolytic activity and expression, decrease ß-Catenin expression and increase Vimentin expression in MDA-MB-231 cells. Inhibition of the oncoprotein c-Src reverses all the effects induced by CPF in MDA-MB-231 but not in MCF-7 indicating that c-Src is a kinase with a crucial role in the cells which grow in an estrogen-independent way. In MCF-7 cells both c-Src and estrogen receptor alpha must be blocked to completly inhibit the CPF-mediated effects. Our results show for the first time that the exposure to subthreshold concentrations of CPF promotes the modulation of EMT-molecular markers and pathways. These results, together with the ubiquitous distribution of the pesticide CPF, make it of utmost importance to take measures to minimize the risk of exposure to this compound.


Assuntos
Movimento Celular/efeitos dos fármacos , Clorpirifos/toxicidade , Disruptores Endócrinos/toxicidade , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Praguicidas/toxicidade , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteína Tirosina Quinase CSK/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Relação Dose-Resposta a Droga , Transição Epitelial-Mesenquimal/genética , Receptor alfa de Estrogênio/genética , Feminino , Humanos , Células MCF-7 , Metaloproteinase 2 da Matriz/genética , Transdução de Sinais
3.
J Small Anim Pract ; 61(8): 504-511, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32692404

RESUMO

OBJECTIVE: To describe the clinical features and outcome of functional thyroid tumours in dogs. MATERIALS AND METHODS: Retrospective multi-institutional study of 70 dogs diagnosed with thyroid mass and concurrent hyperthyroidism. Clinical data regarding presentation, treatment, outcome and functional thyroid status were retrieved. RESULTS: Overall median survival of dogs with functional thyroid tumours was 35.1 months and 1- and 3-year survival rates were 83 and 49%, respectively. Median survival time was 72.6 months for dogs treated with surgical excision and 15.7 months for dogs that did not receive surgery. Of the 50 dogs treated by surgery and for which thyroid status was known following treatment, 64% developed hypothyroidism after surgery. Histopathologically confirmed metastasis was identified in 3% of dogs. CLINICAL SIGNIFICANCE: Dogs with functional thyroid tumours may survive a long time after surgical excision, although post-operative hypothyroidism is common.


Assuntos
Doenças do Cão , Hipotireoidismo/veterinária , Neoplasias da Glândula Tireoide/veterinária , Animais , Cães , Estudos Retrospectivos , Resultado do Tratamento
4.
J Steroid Biochem Mol Biol ; 186: 96-104, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30290214

RESUMO

Chlorpyrifos (CPF) is an organophosphorus pesticide used for agricultural pest control all over the world. We have previously demonstrated that environmental concentrations of this pesticide alter mammary gland histological structure and hormonal balance in rats chronically exposed. In this work, we analyzed the effects of CPF on mammary tumors development. Our results demonstrated that CPF increases tumor incidence and reduces latency of NMU-induced mammary tumors. Although no changes were observed in tumor growth rate, we found a reduced steroid hormone receptor expression in the tumors of animals exposed to the pesticide. Moreover, we analyzed the role of epigenetic mechanisms in CPF effects. Our results indicated that CPF alters HDAC1 mRNA expression in mammary gland, although no changes were observed in DNA methylation. In summary, we demonstrate that the exposure to CPF promotes mammary tumors development with a reduced steroid receptors expression. It has also been found that CPF affects HDAC1 mRNA levels in mammary tissue pointing that CPF may act as a breast cancer risk factor.


Assuntos
Neoplasias da Mama/induzido quimicamente , Neoplasias da Mama/genética , Clorpirifos/efeitos adversos , Epigênese Genética/efeitos dos fármacos , Metilnitrosoureia , Praguicidas/efeitos adversos , Animais , Neoplasias da Mama/patologia , Metilação de DNA/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona Desacetilase 1/genética , Humanos , Ratos , Ratos Sprague-Dawley
5.
Toxicol Lett ; 270: 72-79, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28215542

RESUMO

Hexachlorobenzene (HCB) is an organochlorine pollutant widely distributed in the environment around the entire world. Previous reports from our group and others have demonstrated that this compound is as an endocrine disruptor. We have also reported that HCB presents a co-carcinogenic effect in N-Nitroso-N-methyl-urea-induced mammary tumours in rats. In this work, we studied the effects of HCB on cell cycle progression and cell cycle regulating protein expression in the estrogen-sensitive breast cancer cell line, MCF-7. Here, we show that HCB alters cell cycle in a concentration-dependent way. The lowest assessed concentration (0.005µM) promotes the cell cycle progression, enhances cyclin D1 expression, and reduces the nuclear localization of p27 accompanied by an increased interaction between p27 and c-Src kinase. On the other hand, 5µM HCB delays the cell cycle progression and promotes the formation of the cyclin E-CDK2-p27 protein complex. Our results show that HCB stimulates cell proliferation through cell cycle modulation and c-Src involvement in MCF-7 cells. Here, we report for the first time that differential mechanisms of action of HCB on mammary cell cycle progression are triggered at different concentrations of this pollutant.


Assuntos
Ciclo Celular/efeitos dos fármacos , Ciclina E/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Hexaclorobenzeno/toxicidade , Proteínas Oncogênicas/metabolismo , Quinases da Família src/metabolismo , Proteína Tirosina Quinase CSK , Divisão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ciclina D1/genética , Ciclina D1/metabolismo , Ciclina E/genética , Quinase 2 Dependente de Ciclina/genética , Inibidor de Quinase Dependente de Ciclina p27/genética , Humanos , Células MCF-7 , Proteínas Oncogênicas/genética , Fosforilação , Quinases da Família src/genética
6.
Ital J Pediatr ; 42(1): 87, 2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27658827

RESUMO

BACKGROUND: Infants born at 34 to 36 weeks of gestation (late preterm) are at greater risk for adverse outcomes than those born at 37 weeks of gestation or later. Aim of this paper is to examine risk factors for late preterm births and to investigate the complications of the transition period in late preterm infants (LPIs). METHODS: All consecutive late preterm deliveries, excluded stillbirths, were included. Maternal and neonatal data, need for delivery room resuscitative procedures, temperature at birth (T1) and two hours after the admission (T2) were analyzed in all LPIs stratified by Gestational Age (GA) and divided into three groups (34, 35 and 36 weeks). RESULTS: Two hundred seventy-six LPIs were analyzed. Pregnancy complications were present in 72 mothers (26.1 %), more frequently at 34 weeks of gestation respect to 35 and 36 weeks (p = 0.008, p = 0.006 respectively). Forty seven LPIs (17.1 %) needed for any resuscitation and 37 (13.4 %) were ventilated at birth. LPIs at 34 weeks were significantly more likely to receive ventilation respect to those at 35 and 36. At T1 the mean temperature resulted lower at 34 weeks respect to 36 weeks (p = 0.03). At T2 respect to T1, the rate of normothermic neonates increased at 35 and 36 weeks (p = 0.003, p = 0.005, respectively). Hypoglicemia rate was similar among the groups; 66.7 % of hypoglicemic neonates were hypothermic at T1. The rate of respiratory diseases and NICU admission decreased with increasing GA. Higher number of neonates ventilated at birth developed respiratory disorders respect to those unventilated (40.5 % vs 8.4 %; p < 0.001). CONCLUSIONS: Transition period in LPIs may become critical, as resuscitation strategies can be required and heat loss can occur. LPIs, especially at 34 gestational weeks, are higher-risk group needing adequate and targeted management at birth.

7.
Lupus ; 24(3): 231-4, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25504650

RESUMO

Neonatal antiphospholipid syndrome (neonatal APS) seems to be exceedingly rare, as the antiphospholipid antibodies (aPL) related thrombosis in the neonatal period. The pathogenesis of perinatal aPL related thrombosis may be explained both by the transplacental passage of the maternal antibodies and by the production of de novo antibodies by the neonate. However, few cases of neonatal APS are reported in the literature, especially regarding arterial thrombotic events. In particular, only two cases of neonatal aPL related isolated cerebral sinovenous thrombosis (CSVT) are described in the literature. Despite its frequency, CSVT results in significant mortality and morbidity, probably also due to the difficulty in early diagnosis and then in correct managing in the neonatal period. A diagnosis of neonatal APS should be considered in the evaluation of neonates with CSVT, as well as in any case of neonatal thrombosis, to correctly manage the affected neonates and counsel the mother for future pregnancies.


Assuntos
Síndrome Antifosfolipídica/complicações , Trombose Intracraniana/imunologia , Humanos , Recém-Nascido , Masculino
8.
Meat Sci ; 82(2): 247-51, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20416745

RESUMO

The objective of this study was to evaluate the effect of sweet lupin (Lupinusalbus L. var. Multitalia) as a substitute for soybean (Glicinemax [L] Merr.) in feed on the productive performance and meat quality of Podolian young bulls. The steers were divided into 2 homogeneous groups and were fed durum wheat (Triticumdurum L.), straw and a complete pellet feed containing 20% sweet lupin seeds or 16.5% soybean. Productive performances were similar for both groups. The values of pH, measured on Longissimuslumborum and Semitendinosus muscles 24h after slaughter, were similar. No differences were shown between groups regarding the colour characteristics of both muscles or the tenderness of the cooked meat. No statistical differences were found between diets regarding the fatty acid profile of meats, except for a significantly higher incidence of linoleic acid in the meat obtained from animals on soybean feed. In conclusion, comparable results were obtained when soybean was replaced with sweet lupin seeds in complete pellet feed for Podolian steers.

9.
J Endocrinol Invest ; 29(7): 619-24, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16957410

RESUMO

OBJECTIVE: The relative contribution of fasting and post-prandial glucose to glycated hemoglobin (HbA1c) is controversial. In the present study, we assessed the relationship with HbA1c of fasting and post-prandial glucose measured in a more naturalistic setting, through home glucose self-monitoring or with a continuous glucose monitoring system (CGM). MATERIALS AND METHODS: A consecutive series of 300 patients with Type 2 diabetes were enrolled in the study, provided that they performed blood glucose self-monitoring. HbA1c and fasting plasma glucose (FPG) were measured at enrolment. RESULTS: Both fasting plasma and capillary glucose showed a significant correlation with HbA1c (r=0.66 and 0.61, respectively; p<0.001). When home glucose monitoring was considered, both mean fasting and post-prandial glucose showed a significant correlation with HbA1c (r=0.71 and 0.73, respectively). In patients in the lower tertile of body mass index (BMI), HbA1c showed a significant correlation at multivariate analysis with post-prandial glucose, but not with fasting glucose. In patients with HbA1c >7%, both fasting and post-prandial glucose showed a significant correlation, after adjustment for age and BMI, with HbA1c (both p<0.01); conversely, in those with HbA1c < or =7%, such a correlation could be observed for fasting (p<0.01), but not for post-prandial glucose. CONCLUSION: In conclusion, both fasting and post-prandial glucose contribute to the determination of HbA1c . Home glucose self-monitoring appears to provide a more accurate assessment of metabolic control than a single plasma glucose measurement in experimental conditions. Fasting glucose could provide a greater contribution to HbA1c in patients with lower HbA1c, while post-prandial glucose seems to play a major role in leaner Type 2 diabetic subjects.


Assuntos
Glicemia/análise , Diabetes Mellitus Tipo 2/sangue , Jejum/sangue , Hemoglobinas Glicadas/análise , Período Pós-Prandial , Idoso , Automonitorização da Glicemia/estatística & dados numéricos , Pressão Sanguínea , Índice de Massa Corporal , Colesterol/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estatística como Assunto
12.
Med Princ Pract ; 13(4): 220-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15181328

RESUMO

OBJECTIVE: The aim of this work was to analyze the effect of estradiol (E(2)), medroxyprogesterone and the two selective estrogen receptor modulators (SERMs) (tamoxifen (Tam) and raloxifene (Ral)) on the estrogen receptor (ER) conformers profile performed by size exclusion HPLC in relation to hormone dependence of mammary tumors. MATERIALS AND METHODS: Two types of mammary tumors were studied: tumors transplanted in BALB/c mice that are medroxyprogesterone acetate (MPA)-dependent for growth, and tumors induced in Sprague-Dawley rats by intraperitoneal injection of N-nitroso-N-methylurea (NMU). Tumors from mice treated with MPA, E(2), Tam or Ral and NMU-treated rats were analyzed and compared to that of control. RESULTS: The tumor conformer profiles were as follows: control and MPA-treated mice showed only one peak (oligomeric form); E(2)-treated mice also showed only one peak (dimer); Tam-treated mice showed one peak corresponding to a possible proteolytic fragment, and Ral-treated mice showed two peaks (oligomeric and a possible proteolytic fragment). On the other hand, NMU-induced mammary tumors from rats showed three peaks (oligomeric, monomeric and proteolytic). CONCLUSION: Our findings may indicate that SERMs affect the aggregation state of ER and thereby its ability to modulate genomic transcription mechanisms related to growth rate.


Assuntos
Neoplasias Mamárias Experimentais/metabolismo , Cloridrato de Raloxifeno/farmacologia , Receptores de Estrogênio/metabolismo , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tamoxifeno/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Metilnitrosoureia , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Hormônio-Dependentes/metabolismo , Conformação Proteica , Ratos , Ratos Sprague-Dawley , Receptores de Estrogênio/química
14.
Oncol. clín ; 7(4): 810-814, nov. 2002. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-330243

RESUMO

La insulina, miembro de la familia de factores de crecimiento que incluyen al factor de crecimiento tipo insulina I (IGF-I) y II (IGF-II), presenta efectos mitogénicos sobre células epiteliales mamarias normales y malignas (Goodwin y col., 2002). Se postula que altos niveles de insulina permiten identificar mujeres con una mala evolución de su cáncer de mama, en quienes deberán aplicarse estrategias terapéuticas más efectivas. Se estudiaron 32 pacientes con cáncer de mama, de las cuales 18 presentaron carcinoma ductal invasor, incluidos 3 multifocales (56 por ciento), 6 carcinoma lobulillar infiltrante (19 por ciento), 3 carcinoma papilar (10 por ciento) y el resto otros tipos (15 por ciento). Dos pacientes (7 por ciento) presentan diabetes mellitus no-insulino dependiente. Los niveles de insulina plasmática en ayunas determinados por RIA (Insulin-CT kit) resultaron en: 18 pacientes (56 por ciento) con niveles normales (5,5 a 19,9 µUI/ml), el resto (44 por ciento) con insulinemias superiores al normal. La insulinemia plasmática en ayunas en voluntarias sanas resultó ser de 13,9ñ4,3 µUI/ml (n=10)...


Assuntos
Humanos , Adulto , Feminino , Pessoa de Meia-Idade , Neoplasias da Mama , Carcinoma Intraductal não Infiltrante , Carcinoma Lobular , Carcinoma Papilar , Insulina , Antagonistas da Insulina , Biomarcadores Tumorais , Neoplasias da Mama , Insulina , Metástase Linfática , Prognóstico , Receptores de Estrogênio , Receptores de Progesterona , Receptores de Somatomedina , Taxa de Sobrevida
15.
Oncol. clín ; 7(4): 810-814, nov. 2002. ilus, tab
Artigo em Espanhol | BINACIS | ID: bin-6882

RESUMO

La insulina, miembro de la familia de factores de crecimiento que incluyen al factor de crecimiento tipo insulina I (IGF-I) y II (IGF-II), presenta efectos mitogénicos sobre células epiteliales mamarias normales y malignas (Goodwin y col., 2002). Se postula que altos niveles de insulina permiten identificar mujeres con una mala evolución de su cáncer de mama, en quienes deberán aplicarse estrategias terapéuticas más efectivas. Se estudiaron 32 pacientes con cáncer de mama, de las cuales 18 presentaron carcinoma ductal invasor, incluidos 3 multifocales (56 por ciento), 6 carcinoma lobulillar infiltrante (19 por ciento), 3 carcinoma papilar (10 por ciento) y el resto otros tipos (15 por ciento). Dos pacientes (7 por ciento) presentan diabetes mellitus no-insulino dependiente. Los niveles de insulina plasmática en ayunas determinados por RIA (Insulin-CT kit) resultaron en: 18 pacientes (56 por ciento) con niveles normales (5,5 a 19,9 AUI/ml), el resto (44 por ciento) con insulinemias superiores al normal. La insulinemia plasmática en ayunas en voluntarias sanas resultó ser de 13,9ñ4,3 AUI/ml (n=10)...(AU)


Assuntos
Humanos , Adulto , Feminino , Pessoa de Meia-Idade , Idoso , Neoplasias da Mama/diagnóstico , Biomarcadores Tumorais , Carcinoma Intraductal não Infiltrante , Carcinoma Lobular , Carcinoma Papilar , Insulina/sangue , Antagonistas da Insulina/uso terapêutico , Neoplasias da Mama/fisiopatologia , Neoplasias da Mama/patologia , Prognóstico , Insulina/diagnóstico , Receptores de Estrogênio , Metástase Linfática , Receptores de Progesterona , Receptores de Somatomedina , Taxa de Sobrevida
16.
Artigo em Inglês | MEDLINE | ID: mdl-11574288

RESUMO

Treatment with exogenous spermidine enhanced acute malathion toxicity during larval development of the toad Bufo arenarum Hensel. The polyamine was rapidly incorporated in the larvae with a subsequent metabolization to putrescine and spermine, which were excreted to the media. Endogenous polyamine levels were not changed by either spermidine or malathion treatments. However, 0.5-mM spermidine modified malathion uptake and bioavailability increasing the concentration of the xenobiotic in the larvae. The amount of reduced thiols was decreased by both compounds, but the depletion was insufficient to induce cytotoxicity. The oxidative degradation of polyamines competes for the pool of reduced glutathione used in the conjugation of malathion in the larvae, thus leading to the reported potentiation of toxicity. Our results suggest that exposure to thiols-depleting agents may induce alteration of organophosphate degradation in amphibian larvae.


Assuntos
Bufo arenarum/crescimento & desenvolvimento , Malation/toxicidade , Sinergistas de Praguicidas/farmacologia , Espermidina/farmacologia , Compostos de Sulfidrila/metabolismo , Animais , Disponibilidade Biológica , Biotransformação/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Dissulfeto de Glutationa/efeitos dos fármacos , Larva/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Malation/farmacocinética , Oxirredução , Sinergistas de Praguicidas/farmacocinética , Espermidina/farmacocinética
17.
Oncol. clín ; 5(3): 426-435, sept. 2000. ilus
Artigo em Espanhol | LILACS | ID: lil-318469

RESUMO

Las terapias oncológicas conllevan generalmente efectos secundarios indeseados por lo que el mejor conocimiento de los mecanismos regulatorios del desarrollo y crecimiento tumoral puede abrir el camino a enfoques terapeúticos más adecuados. El objetivo de éste trabajo fue profundizar el estudio de la implicancia de factores que regulan el crecimiento del cáncer mamario empleando un modelo experimental químicamente inducido en rata, el que presenta similitudes con el cáncer mamario humano principalmente en lo que respecta a la regulación hormonal de su crecimiento. El tumor mamario fue inducido químicamente en ratas normales y diabéticas. Se analizó la expresión de receptores a factor de crecimiento insulínico tipo I (RIGF-I), el que forma parte de un sistema formado por factores de crecimiento, sus receptores y proteínas transportadas; éste sistema se encuentra alterado en pacientes con diabetes mellitus no dependiente de insulina. También se analizó la expresión de las proteínas c-FOS y PCNA (antígeno nuclear de proliferación celular), ambas relacionadas con la proliferación celular. Los resultados experimentales mostraron significativas diferencias en los tumores mamarios desarrollados: los de las ratas diabéticas presentaron mayor período de latencia (p<0,001), menor número de tumores desarrollados por rata (p<0,02) y una velocidad de crecimiento menor (p<0,05) con respecto a los tumores desarrollados en ratas normales. Asimismo, mostraron un patrón histológico de marcada benignidad, en contraste con los adenocarcinomas malignos ductales desarrollados en los animales normales. La expresión de las proteínas c-FOS y PCNA detectada por métodos inmunohistoquímicos fue significativamente menor en los tumores de las ratas diabéticas que en ratas normales. En cuanto a la expresión de RIGF-I, los resultados indicaron que la misma estaría regulada por las hormonas esteroides en animales diabéticos y normales. El trabajo permitió analizar experimentalmente la interrelación entre factores de crecimiento insulínicos y hormonas esteroides en el desarrollo y crecimiento tumoral mamario, particularmente cuando están presentes la patología mamaria y la diabetes


Assuntos
Animais , Ratos , Antígeno Nuclear de Célula em Proliferação , Neoplasias Mamárias Experimentais , Receptor IGF Tipo 1 , Antagonistas de Estrogênios , Diabetes Mellitus , Diabetes Mellitus Experimental , Genes fos , Imuno-Histoquímica , Neoplasias Mamárias Experimentais , Compostos de Metilureia , Receptor IGF Tipo 1 , Tamoxifeno
18.
Oncol. clín ; 5(3): 426-435, sept. 2000. ilus
Artigo em Espanhol | BINACIS | ID: bin-7535

RESUMO

Las terapias oncológicas conllevan generalmente efectos secundarios indeseados por lo que el mejor conocimiento de los mecanismos regulatorios del desarrollo y crecimiento tumoral puede abrir el camino a enfoques terapeúticos más adecuados. El objetivo de éste trabajo fue profundizar el estudio de la implicancia de factores que regulan el crecimiento del cáncer mamario empleando un modelo experimental químicamente inducido en rata, el que presenta similitudes con el cáncer mamario humano principalmente en lo que respecta a la regulación hormonal de su crecimiento. El tumor mamario fue inducido químicamente en ratas normales y diabéticas. Se analizó la expresión de receptores a factor de crecimiento insulínico tipo I (RIGF-I), el que forma parte de un sistema formado por factores de crecimiento, sus receptores y proteínas transportadas; éste sistema se encuentra alterado en pacientes con diabetes mellitus no dependiente de insulina. También se analizó la expresión de las proteínas c-FOS y PCNA (antígeno nuclear de proliferación celular), ambas relacionadas con la proliferación celular. Los resultados experimentales mostraron significativas diferencias en los tumores mamarios desarrollados: los de las ratas diabéticas presentaron mayor período de latencia (p<0,001), menor número de tumores desarrollados por rata (p<0,02) y una velocidad de crecimiento menor (p<0,05) con respecto a los tumores desarrollados en ratas normales. Asimismo, mostraron un patrón histológico de marcada benignidad, en contraste con los adenocarcinomas malignos ductales desarrollados en los animales normales. La expresión de las proteínas c-FOS y PCNA detectada por métodos inmunohistoquímicos fue significativamente menor en los tumores de las ratas diabéticas que en ratas normales. En cuanto a la expresión de RIGF-I, los resultados indicaron que la misma estaría regulada por las hormonas esteroides en animales diabéticos y normales. El trabajo permitió analizar experimentalmente la interrelación entre factores de crecimiento insulínicos y hormonas esteroides en el desarrollo y crecimiento tumoral mamario, particularmente cuando están presentes la patología mamaria y la diabetes (AU)


Assuntos
Animais , Ratos , Neoplasias Mamárias Experimentais/fisiopatologia , Receptor IGF Tipo 1 , Antígeno Nuclear de Célula em Proliferação , Neoplasias Mamárias Experimentais/patologia , Receptor IGF Tipo 1/efeitos dos fármacos , Diabetes Mellitus , Diabetes Mellitus Experimental , Genes fos , Compostos de Metilureia , Antagonistas de Estrogênios , Imuno-Histoquímica , Tamoxifeno
20.
Eur J Cancer ; 34(6): 889-94, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9797703

RESUMO

The aim of this study was to develop an experimental model for the study of cancer associated with diabetes. For diabetes induction, Sprague-Dawley rats were given streptozotocin (STZ, 90 mg/kg body weight (BW), by intraperitoneal injection on the second day of life. For mammary tumour induction, rats were injected with 50 mg/kg BW of N-nitroso-N-methylurea (NMU) at 50, 80 and 110 days old. The neoplastic process and the effect of tamoxifen treatment was examined in non-diabetic and diabetic rats. The latency period, NMU-induced tumour incidence and the number of tumours per rat in diabetic rats versus controls were 117 +/- 7 days versus 79 +/- 9 days (P < 0.001); 93% versus 95% (NS); and 5.2 +/- 1.6 versus 2.7 +/- 0.5 (P < 0.02). A more benign histological pattern for tumours in diabetic animals was observed. Mammary tumours in diabetic rats grew more slowly than in controls. Tamoxifen (1 mg/kg/day) treated diabetic rats showed tumour regression in 67% of NMU-induced mammary tumours versus 53% in controls (NS). Our results show that tumour progression seems to be affected by diabetes in this experimental model. We suggest this is the result of changes to insulin-like growth factors and their receptors, which occur in diabetics, and our future research will examine this hypothesis.


Assuntos
Anticarcinógenos/uso terapêutico , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/complicações , Neoplasias Mamárias Experimentais/etiologia , Tamoxifeno/uso terapêutico , Animais , Antibacterianos , Carcinógenos/toxicidade , Divisão Celular , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/patologia , Feminino , Insulina/sangue , Neoplasias Mamárias Experimentais/sangue , Neoplasias Mamárias Experimentais/patologia , Metilnitrosoureia/toxicidade , Ratos , Estreptozocina
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