RESUMO
Intermittent hypobaric hypoxia (IHH) induced a decrease in sperm count and oxidative damage in epididymis. We have previously demonstrated that a blueberry-enriched polyphenol extract (BB-4) reduced the adverse effects of oxidative stress in rat testis under hypobaric hypoxia. The aim of this study was to evaluate whether BB-4 could reverse oxidative stress in epididymis. To evaluate the protective role of BB-4 in epididymis, male rats were exposed to IHH. Lipid peroxidation, (LPO) expression and activity of glutathione reductase (GR) were evaluated. Our results showed a reduction in LPO and a decrease in GR activity in rat epididymis exposed to IHH. These results suggest that BB-4 can prevent the effects of IHH in rat epididymis.
Assuntos
Mirtilos Azuis (Planta) , Epididimo/patologia , Hipóxia/prevenção & controle , Animais , Peroxidação de Lipídeos , Masculino , Ratos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
In Chile, due to the intensive activity developed in confining areas of the Andes Mountains ranging in altitude over 4000 asl, there has been an increasing intermittent movement of human resources to high altitude conditions. This unusual condition, defined as hypobaric hypoxia, affects notoriously in any living organism and there shows a series of physiological responses. Studies performed in rats under chronic hypobaric hypoxia and intermittent hypobaric hypoxia have registered changes in testicular morphology together with loss of spermatogenic cells in all stages of spermatogenic cycle. Furthermore, recent tests reinforced the existence of an oxidative metabolism in epididymis of rats subjected to hypobaric hypoxia due to the increase in the regulator enzyme expression of reactive oxygen species (ROS), This increase in the production of ROS induced a rise in apoptosis at germinal cell level, leading to a state of hypo-spermatogenesis that may jeopardise masculine fertility. Therefore, the eventual development of oxidative stress in spermatogenic cells and consequently the spermatozoids of workers subjected to high altitude, either chronic or intermittent, turns out to be critical when it poses as an imminent risk to the viability and quality of the reproductive cells of workers subjected to intermittent hypobaric hypoxia.
Assuntos
Genitália Masculina/metabolismo , Hipóxia/metabolismo , Estresse Oxidativo , Animais , Humanos , Infertilidade Masculina , MasculinoRESUMO
Evidence has accumulated on the role of reactive oxygen species (ROS) in metastasis since surgical removal of tumors generates oxidative stress promoting metastasis and cell growth. Metastasis consists of a cascade of events which allow the cell to survive in target tissues and influence several processes such as dissemination from tumor tissue, transport in blood/lymphatic vessels, invasion and homing of malignant cells. A cDNA oligoarray was used to determine whether alterations of metastatic genes are associated with oxidative stress in breast cancer cell lines. The cell lines used for the experiments were derived from a pre-existent in vitro breast cancer progression model originated in our laboratory. The cDNA array showed alterations in functional gene groups related with cell-cell and cell-matrix interaction molecules, such as caveolin-1; metastasis suppressor genes, such as CD44; metastasis-associated proteases, such as cathepsin D and the protease inhibitor, plasminogen activator inhibitor type 1. The changes of the selected genes were validated by differential display-RT-PCR as well as by protein expression assessed by Western blot analysis. It was found that the cell line, called Tumor2 with down-regulation of basal ROS and manganese superoxide dismutase (MnSOD) expression as a constitutive pattern of this cell line, presented alterations in genes that confer metastatic potential in comparison to the Alpha5 cell line, showing overexpression of basal MnSOD and high levels of ROS. Interesting, it was to found that CD44, considered a metastatic suppressor gene, was influenced by ROS, measured by hydrogen peroxide treatments, as seen by decreased CD44 protein expression in the Alpha5 cell line in a compensatory response to increased MnSOD protein expression. In conclusion, alterations of metastatic genes in malignant breast cancer cell lines were observed in relation to ROS and basal levels of antioxidant enzymes.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/metabolismo , Metástase Neoplásica/genética , Estresse Oxidativo/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/farmacologiaRESUMO
The presence of prostate cancer cells in bone marrow of patients with clinically localized disease is associated with increased chance of disease recurrence. The presence of prostate specific antigen (PSA) in bone marrow aspirates has been used to indicate the presence of micrometastasis. The aim of this study was to present a prospective study of prostate cancer patients to determine the presence of cells that express PSA in aspirates taken from bone marrow and to compare with bone marrow biopsy samples. Results indicated a significant difference between the frequency of cells detected in bone marrow aspirate and biopsy samples (P<0.0002) when all patients were considered. There was no difference between the frequencies of cells detected in bone marrow aspirate and biopsy of patients analyzed before treatment. However, there was a significant (P<0.003) difference between them after treatment. There was also a significant difference in the frequency of PSA positive cells detected (P<0.005) in Stages I to IV as well as in the frequency of cells detected (P<0.0002) when analyzed according to Gleason score. The present results explain the lack of correlation between positive aspirates and prognosis in numerous clinical cases.
Assuntos
Neoplasias da Medula Óssea/secundário , Medula Óssea/patologia , Antígeno Prostático Específico/biossíntese , Neoplasias da Próstata/patologia , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha Fina , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de NeoplasiasRESUMO
Lung cancer can originate from exposure to exogenous and endogenous environmental carcinogens. The use of organophosphorus insecticides has significantly increased in agricultural environments and in urban settings. There is evidence that estrogen can increase lung cancer risk in women. The aim of the present study was to analyze morphological and molecular alterations induced by malathion (M) and 17beta-estradiol (E2) in rat lung tissues. There were four groups: saline solution (control) (100 microg/100 g body weight; BW), M (22 mg/100 g BW), E2 (30 microg/100 gr BW) and combination of both. The animals were injected over a 5-day period and sacrificed 240 days after treatments and lung tissues were excised and analyzed for morphological alterations. Morphometric analysis indicated that M plus E2-treated animals showed a significantly (P<0.05) higher incidence of parenchyma with alveolar proliferative lesions (PAPL), preneoplastic lesions in bronchiolar epithelium (hyperplasia, metaplasia, carcinoma in situ and invasive carcinoma) and atypical lymphatic morphology (lymphatic cell aggregates; LCA) than M or E2 alone-treated and control animals after 240 days. Molecular biology studies indicated that c-ErbB2 and Rho-A had higher protein expression in M plus E2-treated animals in comparison to control and either M- or E-treated animals. In summary, the combination of M and E2 sharply induced pathological lesions in lung alveolar parenchyma, bronchiolar epithelia and lymphatic tissues, in comparison to control animals or in animals treated with either substance alone. These results indicated an increase in risk of rodent lung tumor formation by environmental and endogenous substances.
Assuntos
Estradiol/toxicidade , Estrogênios/toxicidade , Inseticidas/toxicidade , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/patologia , Malation/toxicidade , Animais , Feminino , Imuno-Histoquímica , Pulmão/efeitos dos fármacos , Pulmão/patologia , Ratos , Ratos Sprague-Dawley , Receptor ErbB-2/biossíntese , Receptor ErbB-2/efeitos dos fármacos , Proteína rhoA de Ligação ao GTP/biossíntese , Proteína rhoA de Ligação ao GTP/efeitos dos fármacosRESUMO
The identification of genes involved in the process of neoplastic transformation is essential for analyzing the progression of breast cancer when induced by endogenous and exogenous agents, among which are the estrogens and the organophosphorous pesticides, respectively. It is important to consider the impact of such substances when they are present in combination. In vitro experimental models are needed in order to understand breast carcinogenesis. The aim of this work was to examine the effect of 17beta estradiol (estrogen) combined with either malathion or parathion on the transformation of human breast epithelial cells in vitro. Results showed that estrogen combined with either malathion or parathion altered cell proliferation and induced cell transformation as well as exhibited significant invasive capabilities as compared to the control MCF-10F cell line. Several genes were up-regulated by the effect of all of the treatments, such as the cyclins, cyclin D1 and cyclin-dependent kinase 4, IGFBP3 and IGFBP5, and keratin 18. The c-Ha-ras oncogene was up-regulated by the effect of malathion alone and with the combination of estrogen and either malathion or parathion. The DVL1 gene was up-regulated only with malathion alone and the combination of parathion with estrogen. Expression of the HSP 27, MCM2 and TP53 inducible protein 3 genes was up-regulated with malathion alone and with the combination of estrogen and either malathion or parathion while TP53 (Li-Fraumeni syndrome) was up-regulated by estrogen alone and malathion alone. Thus, we suggest that pesticides and estrogens affect human breast cells inducing molecular changes indicative of transformation.
Assuntos
Mama/efeitos dos fármacos , Mama/metabolismo , Estrogênios/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genes Neoplásicos , Malation/toxicidade , Paration/toxicidade , Mama/citologia , Linhagem Celular , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Perfilação da Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , FenótipoRESUMO
The association between breast cancer initiation and prolonged exposure to estrogen suggests that this hormone may also have an etiologic role in such a process. On the other hand, many studies have found an association between human cancer and exposure to agricultural pesticides such as parathion, an organophosphorous pesticide used in agriculture to control mosquito plagues. However, the key factors behind the initiation of breast cancer remain to be elucidated. The aim of this study was to determine the effect of 17beta estradiol (estrogen) and parathion on protein expression in cell transformation of human breast epithelial cells in vitro. Estrogen and parathion alone and in combination induced malignant transformation of an immortalized human breast epithelial cell line, MCF-I0F, as indicated by anchorage independency and invasive capabilities. The results indicate that a combination of estrogen and parathion increased the expression of related cell adhesion proteins such as Dvl, Notch, CD146 and beta catenin. In conclusion, it can be suggested that pesticides affect human breast cell adhesion changes indicative of transformation.
Assuntos
Mama/efeitos dos fármacos , Moléculas de Adesão Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Estradiol/toxicidade , Inseticidas/toxicidade , Paration/toxicidade , Proteínas Adaptadoras de Transdução de Sinal/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Mama/metabolismo , Antígeno CD146/efeitos dos fármacos , Antígeno CD146/metabolismo , Linhagem Celular Tumoral , Transformação Celular Neoplásica/efeitos dos fármacos , Proteínas Desgrenhadas , Feminino , Humanos , Imuno-Histoquímica , Fosfoproteínas/efeitos dos fármacos , Fosfoproteínas/metabolismo , Receptores Notch/efeitos dos fármacos , Receptores Notch/metabolismo , beta Catenina/efeitos dos fármacos , beta Catenina/metabolismoRESUMO
Environmental chemicals may be involved in the etiology of breast cancer. Among them, organophosphorous compounds are the most widely used pesticides because of their extensive use in agriculture, medicine and industry. The risk of breast cancer is associated with prolonged exposure to female hormones and is attributed to estrogen since prolonged stimulation by steroid hormones may increase cell division. The aim of the present study was to identify the differentially expressed genes encoding enzymes that are important to drug transport and metabolism in parathion- and estrogen-treated human breast epithelial cell lines using cDNA microarrays. MCF-l0F, an immortalized human breast epithelial cell line was treated with parathion and estrogen, either alone or in combination, and malignant cells were developed through a series of sequential steps. Differential expression from the drug metabolism gene array showed that 17 genes were found to be altered either by parathion or estrogen alone, or the combination of both. Among the genes altered by parathion in comparison to the control were CHST5, CHST6 and CHST7 (sulfotransferases); CYP2F1, CYP3A7 and CYP4F3 (CYPs); GSTP1, GSTT2 and MGST1 (GSTs); MT1X (metallothionein); TPMT (methyltransferase); UGT1A1 and UGT2B (UDP glycosyltransferases). The same genes were down-regulated in estrogen alone including several metallothioneins (MT1A, MT1E, MT1H, MT1L and MT2A). The combination of parathion and estrogen induced down-regulation of three sulfotransferases, CYP2F1 and CYP4F3, MGST1, all metallothioneins and TPMT genes. There was no change in CYP3A7, GSTP1, GSTT2, UGT1A1 and UGT2B genes in the presence of both substances. It can be concluded from this study that organophosphorous pesticides such as parathion in the presence of estradiol induced changes in human drug metabolism gene expression in breast cells.
Assuntos
Células Epiteliais , Estrogênios/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Metabólica/genética , Inseticidas/farmacologia , Glândulas Mamárias Humanas/citologia , Paration/farmacologia , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/fisiologia , Feminino , Perfilação da Expressão Gênica , Humanos , Análise de Sequência com Séries de OligonucleotídeosRESUMO
Breast cancer is the most common cancer in women worldwide. Transformation of a normal cell to a malignant one results from mutations in genes that encode key regulatory proteins. Growth factors are proteins secreted by a variety of transformed cells and tumors and function as autocrine regulators of growth. Biomarkers associated with cancer were examined in human breast epithelial cells transformed by high-LET radiation in the presence of 17beta-estradiol. An established cancer model was used in these studies. The MCF-10F cells that were irradiated with double doses of alpha-particles in the presence of estrogen (60 cGy + E/60 cGy + E, named Alpha 5) showed gradual phenotypic changes relative to control, including tumorigenicity in heterologous animals. Protein expression was determined by quantification of immunofluorescence staining coupled with confocal microscopy. The transforming growth factor alpha, epidermal growth factor, ERK1 and fibroblast growth factor-1 (Int2) protein expression was analyzed. Increased protein expression was observed in non-tumorigenic and tumorigenic alpha-irradiated and estrogen-treated cells. However, Stat-1alpha and pS2 protein expression was only increased in the tumorigenic Alpha 5 and Tumor 2 cell lines. It can be concluded that high-LET radiation in the presence of estrogen-induced changes in the proteins associated with growth factors and their overexpression may be a critical step in the cascade of events that characterize progression in breast cancer.
Assuntos
Neoplasias da Mama/fisiopatologia , Substâncias de Crescimento/biossíntese , Neoplasias Induzidas por Radiação/fisiopatologia , Biomarcadores/análise , Mama/citologia , Transformação Celular Neoplásica , Células Epiteliais/efeitos da radiação , Feminino , Perfilação da Expressão Gênica , Substâncias de Crescimento/fisiologia , Humanos , Microscopia Confocal , Fenótipo , Células Tumorais CultivadasRESUMO
We have studied the effects of the organophosphorous pesticide malathion on cell viability, actin cytoskeleton, cell adhesion complex E-cadherin/beta-catenin, and Rho and Rac1 GTPases from the human mammary carcinoma cell line MCF-7. Malathion induced cell lethality, determined by the MTT assay, depending on the treatment conditions. Cells incubated with low concentrations of malathion, 16-32 microg/ml, showed high survival rates (>95%) at any evaluated time (1-5 days), whereas complete cell lethality was found using 512 microg/ml and 5 days of treatment. Deep morphological changes were induced with high doses of 64 and 128 microg/ml, and long incubation time (5 days); cells showed perinuclear vacuoles, rounding, shrinkage, and a gradual loss of adhesion. These changes were related to a decrease in the expression of the adhesion molecules, E-cadherin and beta-catenin, and to the distribution and reactivity of actin microfilaments to TRITC-phalloidin. Disruption of microfilaments, accompanied by the collapse of actin to perinuclear region, were characteristic of cells with loss of adhesion. At lower concentrations, some cells presented deformations on the plasma membrane as lamellipodia-like structures, which were particularly evident from 32 to 128 microg/ml. Conversely, we observed an increase in the expression of Rho and Rac1 GTPases, modulators of actin cytoskeleton and cell adhesion.
Assuntos
Actinas/química , Actinas/metabolismo , Neoplasias da Mama/tratamento farmacológico , Inibidores da Colinesterase/farmacologia , Citoesqueleto/metabolismo , Malation/farmacologia , Western Blotting , Caderinas/biossíntese , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Sobrevivência Celular , Corantes/farmacologia , Proteínas do Citoesqueleto/biossíntese , Citoesqueleto/efeitos dos fármacos , Eletroforese , Humanos , Inseticidas/farmacologia , Microscopia de Fluorescência , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologia , Fatores de Tempo , Transativadores/biossíntese , beta Catenina , Proteínas rac1 de Ligação ao GTP/biossíntese , Proteínas rho de Ligação ao GTP/biossínteseRESUMO
Environmental substances may be involved in the etiology of breast cancers. Many studies have found an association between cancer in humans and exposure to agricultural pesticides. Organophosphorous pesticides have been used to control mosquito plagues. Parathion and malathion, organophosphorous pesticides are cholinesterase inhibitors responsible for the hydrolysis of body choline esters, including acetylcholine at cholinergic synapses. Their primary target of action in insects is the nervous system whereby they inhibit the enzyme acetylcholinesterase at synaptic junction. Atropine is a parasympatholytic alkaloid used as an antidote to acetylcholinesterase inhibitors. We have established an experimental breast cancer model, where epithelial cells in the rat mammary gland underwent a stepwise transformation into malignant cells by exposure to pesticides (Cabello et al, 2001). The aim of this work was to examine whether pesticides were able to induce progression of malignant transformation of a human breast epithelial cell line, MCF7. These results showed that parathion and malathion increased PCNA and induced mutant p53 protein expression of MCF7 cells in comparison to controls and atropine inhibited such action. These results indicated that organophosphorous pesticides can induce more changes in this malignant breast cell line, inducing another step in the progression of the transformation process and atropine on the other hand inhibited the effect of such substances.
Assuntos
Adenocarcinoma/induzido quimicamente , Neoplasias da Mama/induzido quimicamente , Transformação Celular Neoplásica/induzido quimicamente , Células Epiteliais/efeitos dos fármacos , Inseticidas/toxicidade , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Atropina/farmacologia , Mama/citologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Contagem de Células , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Inibidores da Colinesterase/toxicidade , Progressão da Doença , Relação Dose-Resposta a Droga , Feminino , Humanos , Malation/toxicidade , Parassimpatolíticos/farmacologia , Paration/toxicidade , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Environmental chemicals may be involved in the etiology of breast cancers. Many studies have addressed the association between cancer in humans and agricultural pesticide exposure. Organophosphorous pesticides have been used extensively to control mosquito plagues. Parathion and malathion are organophosphorous pesticides extensively used to control a wide range of sucking and chewing pests of field crops, fruits, and vegetables. They have many structural similarities with naturally occurring compounds, and their primary target of action in insects is the nervous system; they inhibit the release of the enzyme acetylcholinesterase at the synaptic junction. Eserine, parathion, and malathion are cholinesterase inhibitors responsible for the hydrolysis of body choline esters, including acetylcholine at cholinergic synapses. Atropine, a parasympatholytic alkaloid, is used as an antidote to acetylcholinesterase inhibitors. The aim of this study was to examine whether pesticides were able to induce malignant transformation of the rat mammary gland and to determine whether alterations induced by these substances increase the cholinergic activation influencing such transformation. These results showed that eserine, parathion, and malathion increased cell proliferation of terminal end buds of the 44-day-old mammary gland of rats, followed by formation of 8.6, 14.3, and 24.3% of mammary carcinomas, respectively, after about 28 months. At the same time, acetylcholinesterase activity decreased in the serum of these animals from 9.78 +/- 0.78 U/mL in the control animals to 3.05 +/- 0.06 U/mL; 2.57 +/- 0.15 U/mL; and 3.88 +/- 0.44 U/mL in the eserine-, parathion-, and malathion-treated groups, respectively. However, atropine alone induced a significant (p < 0.05) decrease in the acetylcholinesterase activity from the control value of 9.78 +/- 0.78 to 4.38 +/- 0.10 for atropine alone, to 1.32 +/- 0.06 for atropine in combination with eserine, and 2.39 +/- 0.29 for atropine with malathion, and there was no mammary tumor formation. These results indicate that organophosphorous pesticides induce changes in the epithelium of mammary gland influencing the process of carcinogenesis, and such alterations occur at the level of nervous system by increasing the cholinergic stimulation.