RESUMO
Human xenografts are extremely useful models to study the biology of human cancers and the effects of novel potential therapies. Deregulation of metabolism, including changes in amino acids (AAs), is a common characteristic of many human neoplasms. Plasma AAs undergo daily variations, driven by circadian endogenous and exogenous factors. We compared AAs concentration in triple negative breast cancer MDA-MB-231 cells and MCF10A non-tumorigenic immortalized breast epithelial cells. We also measured plasma AAs in mice bearing xenograft MDA-MB-231 and compared their levels with non-tumor-bearing control animals over 24 h. In vitro studies revealed that most of AAs were significantly different in MDA-MB-231 cells when compared with MCF10A. Plasma concentrations of 15 AAs were higher in cancer cells, two were lower and four were observed to shift across 24 h. In the in vivo setting, analysis showed that 12 out of 20 AAs varied significantly between tumor-bearing and non-tumor bearing mice. Noticeably, these metabolites peaked in the dark phase in non-tumor bearing mice, which corresponds to the active time of these animals. Conversely, in tumor-bearing mice, the peak time occurred during the light phase. In the early period of the light phase, these AAs were significantly higher in tumor-bearing animals, yet significantly lower in the middle of the light phase when compared with controls. This pilot study highlights the importance of well controlled experiments in studies involving plasma AAs in human breast cancer xenografts, in addition to emphasizing the need for more precise examination of exometabolomic changes using multiple time points.
Assuntos
Aminoácidos/sangue , Ritmo Circadiano/fisiologia , Neoplasias Mamárias Experimentais/fisiopatologia , Neoplasias de Mama Triplo Negativas/fisiopatologia , Aminoácidos/metabolismo , Animais , Neoplasias da Mama/fisiopatologia , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Transplante de Neoplasias , Projetos PilotoRESUMO
Mathematical modelling approaches have become increasingly abundant in cancer research. Tumour infiltration extent and its spatial organization depend both on the tumour type and stage and on the bio-physicochemical characteristics of the microenvironment. This sets a complex scenario that often requires a multidisciplinary and individually adjusted approach. The ultimate goal of this work is to present an experimental/numerical combined method for the development of a three-dimensional mathematical model with the ability to reproduce the growth and infiltration patterns of a given avascular microtumour in response to different microenvironmental conditions. The model is based on a diffusion-convection reaction equation that considers logistic proliferation, volumetric growth, a rim of proliferative cells at the tumour surface, and invasion with diffusive and convective components. The parameter values of the model were fitted to experimental results while radial velocity and diffusion coefficients were made spatially variable in a case-specific way through the introduction of a shape function and a diffusion-limited-aggregation (DLA)-derived fractal matrix, respectively, according to the infiltration pattern observed. The in vitro model consists of multicellular tumour spheroids (MTSs) of an epithelial mammary tumour cell line (LM3) immersed in a collagen I gel matrix with a standard culture medium ("naive" matrix) or a conditioned medium from adipocytes or preadipocytes ("conditioned" matrix). It was experimentally determined that both adipocyte and preadipocyte conditioned media had the ability to change the MTS infiltration pattern from collective and laminar to an individual and atomized one. Numerical simulations were able to adequately reproduce qualitatively and quantitatively both kinds of infiltration patterns, which were determined by area quantification, analysis of fractal dimensions and lacunarity, and Bland-Altman analysis. These results suggest that the combined approach presented here could be established as a new framework with interesting potential applications at both the basic and clinical levels in the oncology area.
Assuntos
Modelos Biológicos , Invasividade Neoplásica/patologia , Invasividade Neoplásica/fisiopatologia , Microambiente Tumoral/fisiologia , Células 3T3-L1 , Adipócitos/citologia , Animais , Linhagem Celular Tumoral , Meios de Cultivo Condicionados , Feminino , Imageamento Tridimensional , Neoplasias Mamárias Experimentais/patologia , Neoplasias Mamárias Experimentais/fisiopatologia , Camundongos , Inoculação de Neoplasia , Esferoides Celulares/patologia , Esferoides Celulares/fisiologiaRESUMO
The origin of human tumors has been attributed to the exposure to several environmental chemicals and implicated in the increase of incidence in breast cancer. Progression of breast cancer follows a complex multistep process that seems to depend on various exogenous and endogenous factors. The aim of this study was to examine the effects of the organo-phosphorous pesticide malathion in the presence of estrogen on neoplastic transformation of rat mammary glands. Virgin female rats were sacrificed after 30, 124 and 240 days of 5-day injections twice a day. There were four groups: i) control, ii) malathion (22 mg/100 g body weight, BW), iii) 17ß-estradiol (30 µg/100 g BW) and iv) combination of both. Progressive alterations in ducts were observed by the effect of malathion in comparison to control after 240 days. Ducts markedly increased in size and number of cells per square millimeter and tumors similar to ductal carcinoma were originated. The increase in number of proliferative ducts per square millimeter was significantly (P<0.05) higher in malathion-treated animals compared to the other groups. Progressive alterations in lobules with estrogen treatment were found after 240 days. Lobules became markedly abnormal, referred to as secretory lobules, increased in number and size and the tumors originated were similar to lobular carcinoma. The increase in number of secretory lobules was significantly (P<0.05) higher in estrogen- treated animals compared to the other groups. Treatment with the combination of malathion and estrogen gave rise to tumors constituted of both proliferative ducts and secretory lobules as well as formation of estrogen metabolites such as 2 and 4 catechol estrogens in the blood of the animals after 240 days. We concluded that morphological changes and alterations in the blood of the animals can be used as biomarkers for mammary gland cancer.
Assuntos
Biomarcadores/sangue , Estrogênios de Catecol/sangue , Neoplasias Mamárias Experimentais/sangue , Neoplasias Mamárias Experimentais/fisiopatologia , Animais , Biomarcadores/metabolismo , Estrogênios de Catecol/metabolismo , Estrogênios de Catecol/farmacologia , Feminino , Malation/farmacologia , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Experimentais/patologia , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND AND PURPOSE: Breast cancer, the most common cancer in women in most countries, is a highly stressful disease. Catecholamines released during stress bind to adrenoceptors and we have recently described alpha(2)-adrenoceptors in human breast cell lines, linked to enhanced cell proliferation. The purpose was to assess the in vivo effects of compounds acting on alpha(2)-adrenoceptors in a reliable model of breast cancer. EXPERIMENTAL APPROACH: The expression of alpha(2)-adrenoceptors was confirmed by immunocytochemistry, immunofluorescence and reverse transcription-PCR in the mouse mammary tumour cell line MC4-L5. Proliferation was assessed by [(3)H]thymidine incorporation and tumours were measured daily. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP digoxigenin nick-end labelling. KEY RESULTS: Incubation for 2 days with alpha(2)-adrenoceptor agonists (clonidine and dexmedetomidine) significantly enhanced proliferation of the mouse mammary tumour cell line MC4-L5. These agonists also significantly stimulated tumour growth of the progestin-dependent tumour C4-HD even in the presence of medroxyprogesterone acetate (MPA). In every tumour tested (C4-HD, CC4-2-HD and CC4-3-HI), regardless of MPA sensitivity, clonidine significantly enhanced tumour growth in the absence of MPA. The alpha(2)-adrenoceptor antagonists, yohimbine and rauwolscine, completely reversed the effects of clonidine. However, the group receiving yohimbine alone showed a nonsignificant but constant increase in tumour growth, whereas rauwolscine alone diminished tumour growth significantly, behaving as a reverse agonist. In CC4-3-HI tumours, rauwolscine treatment enhanced apoptosis and diminished the mitotic index, whereas clonidine had the inverse effect. CONCLUSIONS AND IMPLICATIONS: Alpha(2)-adrenoceptor agonists enhanced tumour growth and rauwolscine behaved in vivo as a reverse agonist, suggesting that it may be tested for adjuvant treatment.
Assuntos
Agonistas de Receptores Adrenérgicos alfa 2 , Agonistas alfa-Adrenérgicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Neoplasias Mamárias Experimentais/tratamento farmacológico , Antagonistas de Receptores Adrenérgicos alfa 2 , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Linhagem Celular Tumoral , Clonidina/farmacologia , Dexmedetomidina/farmacologia , Agonismo Inverso de Drogas , Feminino , Neoplasias Mamárias Experimentais/fisiopatologia , Acetato de Medroxiprogesterona/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Receptores Adrenérgicos alfa 2/metabolismo , Ioimbina/farmacologiaRESUMO
Tumor necrosis factor alpha (TNF alpha) enhances proliferation of chemically-induced mammary tumors and of T47D human cell line through not fully understood pathways. Here, we explored the intracellular signaling pathways triggered by TNF alpha, the participation of TNF alpha receptor (TNFR) 1 and TNFR2 and the molecular mechanism leading to breast cancer growth. We demonstrate that TNFalpha induced proliferation of C4HD murine mammary tumor cells and of T47D cells through the activation of p42/p44 MAPK, JNK, PI3-K/Akt pathways and nuclear factor-kappa B (NF-kappa B) transcriptional activation. A TNF alpha-specific mutein selectively binding to TNFR1 induced p42/p44 MAPK, JNK, Akt activation, NF-kappa B transcriptional activation and cell proliferation, just like wild-type TNF alpha, while a mutein selective for TNFR2 induced only p42/p44 MAPK activation. Interestingly, blockage of TNFR1 or TNFR2 with specific antibodies was enough to impair TNF alpha signaling and biological effect. Moreover, in vivo TNF alpha administration supported C4HD tumor growth. We also demonstrated, for the first time, that injection of a selective inhibitor of NF-kappa B activity, Bay 11-7082, resulted in regression of TNF alpha-promoted tumor. Bay 11-7082 blocked TNF alpha capacity to induce cell proliferation and up-regulation of cyclin D1 and of Bcl-xLin vivo and in vitro. Our results reveal evidence for TNF alpha as a breast tumor promoter, and provide novel data for a future therapeutic approach using TNF alpha antagonists and NF-kappa B pharmacological inhibitors in established breast cancer treatment.
Assuntos
Carcinoma Ductal de Mama/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Neoplasias Mamárias Experimentais/fisiopatologia , Neoplasias Hormônio-Dependentes/fisiopatologia , Receptores Tipo I de Fatores de Necrose Tumoral/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Animais , Proteínas Reguladoras de Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Carcinógenos , Carcinoma Ductal de Mama/induzido quimicamente , Carcinoma Ductal de Mama/tratamento farmacológico , Linhagem Celular Tumoral , Feminino , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/tratamento farmacológico , Acetato de Medroxiprogesterona , Camundongos , Camundongos Endogâmicos BALB C , Proteína Quinase 1 Ativada por Mitógeno/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/efeitos dos fármacos , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Neoplasias Hormônio-Dependentes/induzido quimicamente , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Nitrilas/farmacologia , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Transdução de Sinais/imunologia , Sulfonas/farmacologia , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/imunologiaRESUMO
Breast cancer is the most common worldwide neoplasia in women. The totality of etiology factors of breast cancer is unknown and thus an effective preventive strategy has not been developed. Risk factors associated to breast cancer can be grouped into three broad categories: a) family history (hereditary) factors, b) endocrine and reproductive factors and c) environmental and life-style factors including diet. Animal models of chemical induced mammary carcinogenesis with 7, 12-dimethylbenz[a]anthracene and N-methyl-N-nitrosourea have been useful in the study of biology, treatment and prevention of breast cancer. In this review we show the usefulness and advantages of animal models in the study of nutritional factors associated with breast cancer in order to propose new prevention strategies. We review briefly different experimental approaches as well as some physiologic effects and mechanisms of some nutritional factors studied with animal models of mammary carcinogenesis. Nutritional factors reviewed were: a) energy restriction and high-fat intake, b) soy and phytoestrogens, c) retinoids and carotenoids, d) conjugated linoleic acid, and e) brown seaweed and iodine.
Assuntos
Dieta , Modelos Animais de Doenças , Neoplasias Mamárias Experimentais , 9,10-Dimetil-1,2-benzantraceno , Animais , Carcinógenos , Carotenoides/administração & dosagem , Dieta/efeitos adversos , Dieta com Restrição de Carboidratos , Ingestão de Energia , Ácidos Graxos/administração & dosagem , Feminino , Iodo/administração & dosagem , Neoplasias Mamárias Experimentais/etiologia , Neoplasias Mamárias Experimentais/fisiopatologia , Neoplasias Mamárias Experimentais/prevenção & controle , Metilnitrosoureia , Camundongos , Ratos , Retinoides/administração & dosagem , Fatores de Risco , Alga Marinha , Glycine maxRESUMO
Using medroxyprogesterone acetate (MPA) as a carcinogen, we were able to induce in BALB/c female mice, several progestin-dependent mammary ductal carcinomas that regress completely with estrogen or antiprogestins and are maintained by serial transplantations in syngeneic mice. Progestin-independent variants were subsequently generated or appeared spontaneously. Based on their response to estrogen or antiprogestins, we subdivided them into responsive progestin-independent (R-PI) variants which regress completely and unresponsive progestin-independent (UR-PI) carcinomas which are resistant to both families of compounds. In this study we have investigated progesterone receptor (PR) expression in six responsive progestin-dependent, six R-PI, and three UR-PI tumors. Progestin-dependent and R-PI tumors disclosed a higher expression of the PR(A) isoform as compared with PR(B), as well as an additional band of 78 kDa that was not detected in uterine tissue; all were down-regulated by progestins. UR-PI tumors expressed lower levels of all bands in western blots, but were highly reactive by immunohistochemistry. PR RNA expression was detected in both, UR-PI and R-PI tumors. PR binding was comparable in progestin-dependent and R-PI tumors. In the three UR-PI tumors, only 29/61 (48%) of the samples evaluated showed low binding levels, the rest were negative. This report is the first to describe in an experimental model of breast cancer the expression of PR isoforms and their distribution. Our results suggest the expression of functionally altered isoforms in a subgroup of mammary carcinomas, which may explain their lack of hormone response.
Assuntos
Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/fisiopatologia , Regulação Neoplásica da Expressão Gênica , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/fisiopatologia , Acetato de Medroxiprogesterona/efeitos adversos , Congêneres da Progesterona/efeitos adversos , Progestinas/farmacologia , Receptores de Progesterona/biossíntese , Animais , Western Blotting , Regulação para Baixo , Estrogênios/farmacologia , Feminino , Imuno-Histoquímica , Acetato de Medroxiprogesterona/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Congêneres da Progesterona/administração & dosagem , RNA/biossínteseRESUMO
Carcinomas mamarios murinos, originalmente inducidos por acetato de medroxiprogesterona, con crecimiento autónomo y receptores de estrógenos y progesterona regresionan con estradiol (E2) o con antiprogestágenos. Con el objeto de analizar los mecanismos de la regresión tumoral, estudiamos las características morfológicas y la participación de los reguladores del ciclo celular tales como p21, p27, p53 y MDM2 mediante inmunohistoquímica utilizando dos tumores sensibles al E2 o a los antiprogestágenos y uno sensible al E2 y antiprogestágenos resistente. La regresión se asocia a disminución del parénquima tumoral con aumento del estroma, a un efecto antiproliferativo y proapoptótico y a la inducción de proteínas inhibitorias del ciclo celular tales como p21 y p27. Sin embargo el patrón de expresión de los reguladores del ciclo celular varió. En los tumores sensibles a ambos tratamientos aumentó p21 y p27, los valores basales de p53 fueron altos y los de MDM2 bajos. En el tumor sensible sólo a E2 aumentó únicamente p27 y p21 permaneció en valores bajos acompañados por altos niveles basales de p53 y MDM2. Estos hallazgos sugieren que p21 podría ser esencial para la acción de los antiprogestágenos y que alteraciones en la vía p21/p53 podrían participar en la resistencia al tratamiento hormonal. (AU)
Assuntos
Animais , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/fisiopatologia , Terapia de Reposição Hormonal , Estrogênios/administração & dosagem , Estrogênios/uso terapêutico , Indução de Remissão , Medroxiprogesterona/toxicidade , Estradiol/uso terapêutico , Proteína Supressora de Tumor p53/ultraestrutura , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Progesterona/antagonistas & inibidores , Camundongos Endogâmicos BALB C , Camundongos , Proteína Oncogênica p21(ras)/ultraestrutura , Mitose , ApoptoseRESUMO
A differential effect of pregnancy on the growth of subcutaneous implants of four murine tumors has been observed. Two tumors lacking receptors for progesterone and estrogen [methylcholanthrene-induced fibrosarcoma (MC-C) and spontaneous lymphoid leukemia (LB)] exhibited slow kinetics throughout the course of pregnancy, although inhibition was stronger beyond day 10. On the other hand, one of two tumors bearing receptors for progesterone and estrogen [medroxyprogesterone (MPA)-induced mammary adenocarcinoma (C7HI)] exhibited three phases: up to days 8-10 of gestation the tumor grew faster than in virgins, between days 8-10 and 15 it reached a plateau, and beyond day 15 a sharp reduction in tumor mass was observed. The other tumor [mouse mammary tumor virus (MMTV)-induced mammary carcinoma(T2280)] behaved as a typical pregnancy-dependent tumor (i.e., it grew in pregnant but not in virgin mice, regressed soon after delivery, and reassumed its growth at the middle of a second round of pregnancy). Neither MPA nor estrogen affected MC-C and LB tumor growth. On the other hand, MPA-treated mice enhanced C7HI tumor and reciprocally C7HI tumor-bearing mice treated with estrogen strongly inhibited tumor growth. As for T2280, neither MPA nor estrogen alone could promote tumor growth and, in consequence, no tumor developed. However, when MPA plus estrogen was administered in a schedule simulating the successive appearance of these hormones in pregnancy, T2280 grew even faster than in pregnant mice. When the four tumors were implanted in mice bearing grafts of embryonal tissues (teratomas), all of them were inhibited. This antitumor effect was similar to that observed in pregnancy when tumors unresponsive to progesterone and estrogen were tested. On the other hand, with tumors bearing progesterone and estrogen receptors, differences in tumor growth were detected in pregnant and teratoma-bearing mice. This suggested the existence during pregnancy of two factors potentially acting on tumor growth. First, a progesterone and estrogen-mediated hormonal component, which would exert either inhibitory or stimulatory effects only evidenced with tumors bearing hormonal receptors. Secondly, an antitumor effect proportional to the growing embryonal mass, inhibiting all tumors independently of their origin or hormone responsiveness. This antitumor effect could be attributed to a beat-resistant serum factor (1,000-1,200 Da molecular weight) presumably associated with the pathway of the arachidonic acid metabolism. The interplay between the hormonal component and the serum factor associated with embryonal mass could account for some of the largely heterogeneous and otherwise unexplained effects of pregnancy on tumor growth reported in the literature and illustrated by the four tumors studied here.
Assuntos
Hormônios/fisiologia , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/fisiopatologia , Complicações Neoplásicas na Gravidez/fisiopatologia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Adenocarcinoma/fisiopatologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Estrogênios/farmacologia , Feminino , Fibrossarcoma/tratamento farmacológico , Fibrossarcoma/patologia , Fibrossarcoma/fisiopatologia , Hormônios/farmacologia , Indometacina/farmacologia , Leucemia Linfoide/tratamento farmacológico , Leucemia Linfoide/patologia , Leucemia Linfoide/fisiopatologia , Masculino , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/patologia , Neoplasias Mamárias Experimentais/fisiopatologia , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Neoplasias Experimentais/patologia , Neovascularização Patológica , Gravidez , Complicações Neoplásicas na Gravidez/patologia , Progesterona/metabolismo , Progesterona/farmacologia , Receptores de Progesterona/metabolismo , Teratoma/patologia , Teratoma/fisiopatologiaRESUMO
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 , TamoxifenoRESUMO
We have examined the relationship between the procoagulant activity of F3II mouse mammary carcinoma cells and the production of urokinase, a profibrinolytic serine protease involved in tumor invasion and hematogenous metastasis. F3II cells were capable of inducing the conversion of purified fibrinogen to fibrin in the presence of calcium and plasma traces. Immunocytochemical examination of semi-confluent monolayers demonstrated that F3II cells also synthesized high levels of urokinase. Although fibrinogen did not modify profibrinolytic activity produced by F3II monolayers, fibrin formation increased tumor-derived urokinase activity by two-fold. The present data provide new insights into the cooperative role of coagulation and fibrinolysis facilitating and perpetuating tumor invasion.
Assuntos
Fibrina/farmacologia , Neoplasias Mamárias Experimentais/patologia , Neoplasias Mamárias Experimentais/fisiopatologia , Ativadores de Plasminogênio/biossíntese , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Animais , Meios de Cultivo Condicionados , Feminino , Fibrinogênio/farmacologia , Neoplasias Mamárias Experimentais/enzimologia , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , Células Tumorais Cultivadas , Ativador de Plasminogênio Tipo Uroquinase/biossínteseRESUMO
We have analyzed the anti-invasive properties of the selective synthetic urokinase inhibitor 4-iodo benzo[b]thiopene-2-carboxamidine (B428) in the mouse mammary carcinoma model F3II. At non-cytotoxic concentrations (10-20 microM), B428 blocked secreted and cell-associated tumor-derived urokinase activity as well as whole cell plasminogen-dependent casein degradation. Pretreatment of F3II monolayers with B428 enhanced membrane bound uPA, suggesting that the compound may modify urokinase receptor mobilization and urokinase-dependent cell signaling. B428 exerted a dose-dependent inhibition of Matrigel invasion by F3II cells and also reduced tumor cell adhesion and migration using the same doses. Our data indicate that uPA and its cell surface receptor are involved in attachment, migration, and invasion of mammary tumor cells, and that the three processes can be blocked by a synthetic urokinase inhibitor.
Assuntos
Amidinas/farmacologia , Antineoplásicos/farmacologia , Adesão Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Neoplasias Mamárias Experimentais/fisiopatologia , Invasividade Neoplásica/prevenção & controle , Tiofenos/farmacologia , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Animais , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Meios de Cultivo Condicionados , Feminino , Fibronectinas , Neoplasias Mamárias Experimentais/irrigação sanguínea , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Células Tumorais Cultivadas , Ativador de Plasminogênio Tipo Uroquinase/biossínteseRESUMO
We studied the effect of tumoral microenvironments on metastatic phenotypes. Therefore, murine mammary adenocarcinoma cells cultured in vivo in diffusion chambers (DC) were implanted intraperitoneally in BALB/c mice. The behavior of DC-cultured cells was compared with that of cells obtained from tumors growing subcutaneously or intraperitoneally and from primary cultures in vitro of the former. DC-cultured and control cells were inoculated into normal mice to evaluate their tumorigenicity and metastasizing ability. We found that DC-cultured cells were less tumorigenic and metastatic both in spontaneous and in experimental metastasis assays. The host response to tumor progression resulted in an early leukocytosis, probably due to the overproduction of a hematopoietic factor by the tumor cells. Finally, it was found that DC-cultured cells produced lower levels of urokinase-type plasminogen activator activity, while no differences were found in the metalloproteinase production compared to cells obtained from a tumor growing subcutaneously.
Assuntos
Adenocarcinoma/fisiopatologia , Neoplasias Mamárias Experimentais/fisiopatologia , Adenocarcinoma/patologia , Adenocarcinoma/secundário , Animais , Contagem de Células Sanguíneas , Cultura em Câmaras de Difusão/métodos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Neoplasias Mamárias Experimentais/patologia , Metaloendopeptidases/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Fenótipo , Células Tumorais Cultivadas , Ativador de Plasminogênio Tipo Uroquinase/biossínteseRESUMO
The close interaction between receptors and other transcription factors suggests that their corresponding transducing signals can trigger functional and structural changes in other related molecules. The effect of a progestinic agent, medroxyprogesterone acetate (MPA), on some of the estrogen-receptor (ER) parameters was studied in 2 murine mammary tumor sublines with different progestin hormone dependence for their respective growth. The relative binding affinity of estradiol and tamoxifen for the ER, the receptor content and the ER isoforms studied by HPLC were determined in the hormone-autonomous (HA) and the hormone-dependent (HD) tumor sublines. In the HA subline administration of MPA did not modify the tumor growth rate, whereas this was accelerated in the HD subline. The ER content was clearly increased in the HD tumor subline, but not in the HA subline, compared with the untreated controls. In contrast, the E2 and tamoxifen relative binding affinity for the ER and the isoform profiles were affected by MPA treatment in the HA, but not in the HD tumor subline. The functional change (decrease in relative binding affinity) can be attributed to the appearance of a lower-molecular-size ER isoform under the progestinic treatment. Modifications in one receptor molecule by the action of ligands corresponding to another type of receptor show the interconection between transcription factors and the necessity of broadening conventional concepts regarding hormone dependence in mammary tumorigenesis.
Assuntos
Neoplasias Mamárias Experimentais/fisiopatologia , Acetato de Medroxiprogesterona/farmacologia , Receptores de Estrogênio/metabolismo , Animais , Estradiol/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Tamoxifeno/metabolismoRESUMO
The addition of neoplastic cells (NC) isolated from murine mammary gland adenocarcinomas having moderate and high metastatic ability on in vitro heparinized mice platelet rich plasma (PRP) induced platelet aggregation. One non-metastatic line did not induce aggregation. The aggregatory effect was not correlated with the metastatic abilities. None of the three types of tumors did cause aggregation on whole blood or PRP of rats. These adenocarcinomas seem to be suitable models to study in vitro the interactions between platelets and tumor cells having metastatic and non-metastatic potentials.
Assuntos
Adenocarcinoma/fisiopatologia , Neoplasias Mamárias Experimentais/fisiopatologia , Agregação Plaquetária/fisiologia , Adenocarcinoma/patologia , Animais , Feminino , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Metástase Neoplásica , Ratos , Ratos Wistar , Células Tumorais CultivadasRESUMO
Urokinase-type plasminogen activator (u-PA) plays an important role in tumor growth and metastasis. The aim of this work was to study the u-PA production, in vitro and in vivo, in a transplantable murine mammary adenocarcinoma (M3), moderately metastatic to lung, and in a related tumor variant (MM3), highly metastatic to the same organ, during tumor development. At different times post-transplantation, tumors were employed to prepare either primary cell cultures or homogenates. PA activity from conditioned media (CM), cell lysates (CLs) and tumor homogenates (THs) was quantitated by means of a fibrinolytic assay. Immunoneutralization and zymographic assays were performed to identify the PA present in both tumors. PA activity in CM, CLs and THs, that was undetectable at early stages, increased significantly along the growth of M3 adenocarcinoma. Secreted PA activity in MM3 CM was measurable at early stages and consistently increased up to 37 days post-transplantation, but a marked fall of activity was found at 48 days. PA activity in MM3 THs exhibited the same enhancement and late fall found in vitro. A positive correlation was observed between tumor size and THs PA values in both tumors. The PA present in cell cultures and THs was identified as of the u-PA type. These results support the hypothesis that high u-PA levels are important for tumor invasion and that the stage of tumor development is a critical factor in their PA activity.