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1.
Oncogenesis ; 6(2): e299, 2017 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-28240737

RESUMO

Fatty acid synthase (FASN), the key enzyme for endogenous synthesis of fatty acids, is overexpressed and hyperactivated in a biologically aggressive subset of sex steroid-related tumors, including breast carcinomas. Using pharmacological and genetic approaches, we assessed the molecular relationship between FASN signaling and estrogen receptor alpha (ERα) signaling in breast cancer. The small compound C75, a synthetic slow-binding inhibitor of FASN activity, induced a dramatic augmentation of estradiol (E2)-stimulated, ERα-driven transcription. FASN and ERα were both necessary for the synergistic activation of ERα transcriptional activity that occurred following co-exposure to C75 and E2: first, knockdown of FASN expression using RNAi (RNA interference) drastically lowered (>100 fold) the amount of E2 required for optimal activation of ERα-mediated transcriptional activity; second, FASN blockade synergistically increased E2-stimulated ERα-mediated transcriptional activity in ERα-negative breast cancer cells stably transfected with ERα, but not in ERα-negative parental cells. Non-genomic, E2-regulated cross-talk between the ERα and MAPK pathways participated in these phenomena. Thus, treatment with the pure antiestrogen ICI 182 780 or the potent and specific inhibitor of MEK/ERK, U0126, was sufficient to abolish the synergistic nature of the interaction between FASN blockade and E2-stimulated ERα transactivation. FASN inhibition suppressed E2-stimulated breast cancer cell proliferation and anchorage-independent colony formation while promoting the reduction of ERα protein. FASN blockade resulted in the increased expression and nuclear accumulation of the cyclin-dependent kinase inhibitors p21WAF1/CIP1 and p27Kip1, two critical mediators of the therapeutic effects of antiestrogen in breast cancer, while inactivating AKT, a key mediator of E2-promoted anchorage-independent growth. The ability of FASN to regulate E2/ERα signaling may represent a promising strategy for anticancer treatment involving a new generation of FASN inhibitors.

2.
Nature ; 496(7445): 329-33, 2013 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-23598341

RESUMO

Massive present-day early-type (elliptical and lenticular) galaxies probably gained the bulk of their stellar mass and heavy elements through intense, dust-enshrouded starbursts--that is, increased rates of star formation--in the most massive dark-matter haloes at early epochs. However, it remains unknown how soon after the Big Bang massive starburst progenitors exist. The measured redshift (z) distribution of dusty, massive starbursts has long been suspected to be biased low in z owing to selection effects, as confirmed by recent findings of systems with redshifts as high as ~5 (refs 2-4). Here we report the identification of a massive starburst galaxy at z = 6.34 through a submillimetre colour-selection technique. We unambiguously determined the redshift from a suite of molecular and atomic fine-structure cooling lines. These measurements reveal a hundred billion solar masses of highly excited, chemically evolved interstellar medium in this galaxy, which constitutes at least 40 per cent of the baryonic mass. A 'maximum starburst' converts the gas into stars at a rate more than 2,000 times that of the Milky Way, a rate among the highest observed at any epoch. Despite the overall downturn in cosmic star formation towards the highest redshifts, it seems that environments mature enough to form the most massive, intense starbursts existed at least as early as 880 million years after the Big Bang.

3.
Rev Med Chir Soc Med Nat Iasi ; 112(1): 263-5, 2008.
Artigo em Romano | MEDLINE | ID: mdl-18677939

RESUMO

UNLABELLED: In the world the road traffic accidents are in the 3rd place at WHO cause-of-death statistics. One of the main causes of these accidents is driving fatigue as results of stress. The aim of this study is to monitoring the heart rate variability for identifying the grade of stress of the drivers. MATERIAL AND METHOD: For this stage of the study we design and build an device that recording the ECG signal and the heart rate. We analysed of line the heart rate variability for determining one possible link between the grade of fatigue and heart rate variability. The device use only two electrodes placed on the steering wheel. RESULTS: We use three categories of subjects: beginner drivers, amateur drivers with more than 3 year experience, and expert drivers. The monitoring is made for 30 minutes in intensive traffic. CONCLUSION: The preliminary results are satisfactory which determine us to continuing the research in this direction.


Assuntos
Acidentes de Trânsito/prevenção & controle , Condução de Veículo , Eletrocardiografia , Frequência Cardíaca , Fadiga/prevenção & controle , Humanos , Monitorização Fisiológica
4.
Clin. transl. oncol. (Print) ; 10(4): 219-226, abr. 2008. ilus
Artigo em Inglês | IBECS | ID: ibc-123437

RESUMO

Fatty acid synthase (FASN) is a novel druggable target for metabolically treating and preventing human malignancies. We envisioned that if loss of sensitivity to C75 (a slow-binding FASN inhibitor) occurs in parallel with loss of FASN expression and/or activity, a mathematical assessment of the nature of the interaction between investigational FASN modulators and C75 may predict the ability of experimental compounds to regulate FASN. We statistically compared the arithmetical sums of the anti-proliferative effects obtained when FASN modulators and C75 were used as single agents to those observed experimentally when agents were actually combined in a sequential schedule (i.e., FASN modulator-->C75). A reduced sensitivity to C75 (antagonism) occurred when compounds down-regulated FASN activity/expression, while an enhanced C75 efficacy (synergism) was found following exposure to FASN up-regulators. This "C75-sensitivity test" might offer an easy, rapid and objective method to identify FASN inhibitors with potential anticancer value in human cancer (AU)


No disponible


Assuntos
Humanos , Masculino , Feminino , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Ácido Graxo Sintase Tipo I/administração & dosagem , Ácido Graxo Sintase Tipo I , Modelos Teóricos , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Interferência de RNA , 4-Butirolactona/análogos & derivados , 4-Butirolactona/farmacologia , Western Blotting/métodos , Western Blotting , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/farmacologia , Ácido Graxo Sintase Tipo I/química , Imunofluorescência/métodos
5.
Cell Prolif ; 41(1): 59-85, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18211286

RESUMO

OBJECTIVES: More than 50 years ago, we learned that breast cancer cells (and those of many other types of tumour) endogenously synthesize 95% of fatty acids (FAs) de novo, despite having adequate nutritional lipid supply. Today, we know that breast cancer cells benefit from this phenomenon in terms of enhanced cell proliferation, survival, chemoresistance and metastasis. However, the exact role of the major lipogenic enzyme fatty acid synthase (FASN) as cause, correlate or facilitator of breast cancer remains unidentified. MATERIALS AND METHODS: To evaluate a causal effect of FASN-catalysed endogenous FA biosynthesis in the natural history of breast cancer disease, HBL100 cells (an SV40-transformed in vitro model for near-normal gene expression in the breast epithelium), and MCF10A cells (a non-transformed, near diploid, spontaneously immortalized human mammary epithelial cell line) were acutely forced to overexpress the human FASN gene. RESULTS: Following transient transfection with plasmid pCMV6-XL4 carrying full-length human FASN cDNA (gi: NM 004104), HBL100 cells enhanced their endogenous lipid synthesis while acquiring canonical oncogenic properties such as increased size and number of colonies in semisolid (i.e. soft-agar) anchorage-independent cultures. Anchorage-dependent cell proliferation assays in low serum (0.1% foetal bovine serum), MTT-based assessment of cell metabolic status and cell death ELISA-based detection of apoptosis-induced DNA-histone fragmentation, together revealed that sole activation of endogenous FA biosynthesis was sufficient to significantly enhance breast epithelial cell proliferation and survival. When analysing molecular mechanisms by which acute activation of de novo FA biosynthesis triggered a transformed phenotype, HBL100 cells, transiently transfected with pCMV6-XL4/FASN, were found to exhibit a dramatic increase in the number of phosphor-tyrosine (Tyr)-containing proteins, as detected by 4G10 antiphosphor-Tyr monoclonal antibody. Phosphor-Tyr-specific antibodies recognizing the phosphorylation status of either the 1173 Tyr residue of epidermal growth factor receptor (HER1) or the 1248 Tyr residue of HER2, further revealed that FASN-induced Tyr-phosphorylation at approximately 180 kDa region mainly represented that of these key members of the HER (erbB) network, which remained switched-off in mock-transfected HBL100 cells. ELISA and immunoblotting procedures demonstrated that FASN overactivation significantly increased (> 200%) expression levels of epidermal growth factor receptor and HER2 proteins in HBL100 cells. Proteome Profilertrade mark antibody arrays capable of simultaneously detecting relative levels of phosphorylation of 42 phospho-receptor Tyr-kinases (RTKs) confirmed that acute activation of endogenous FA biosynthesis specifically promoted hyper-Tyr-phosphorylation of HER1 and HER2 in MCF10A cells. This FASN-triggered HER1/HER2-breast cancer-like phenotype was specifically inhibitable either by FASN inhibitor C75 or by Tyr-kinase inhibitors (TKIs) gefitinib (Iressa) and lapatinib (Tykerb) but not by chemotherapeutic agents such as cisplatin. Transient overexpression of FASN dramatically increased HBL100 breast epithelial cells' sensitivity to cytotoxic effects of C75, gefitinib and lapatinib (approximately 8, 10 and > 15 times, respectively), while significantly decreasing (approximately 3 times) cisplatin efficacy. CONCLUSIONS: Although we cannot definitely establish FASN as a novel oncogene in breast cancer, this study reveals for the first time that exacerbated endogenous FA biosynthesis in non-cancerous epithelial cells is sufficient to induce a cancer-like phenotype functionally dependent on the HER1/HER2 duo. These findings may perhaps radically amend our current perspective of endogenously synthesized fat, as on its own, it appears to actively increase signal-to-noise ratio in the HER1/HER2-driven progression of human breast epithelial cells towards malignancy.


Assuntos
Receptores ErbB/metabolismo , Ácido Graxo Sintases/genética , Glândulas Mamárias Humanas/enzimologia , Receptor ErbB-2/metabolismo , Animais , Apoptose , Linhagem Celular , Proliferação de Células , Ativação Enzimática , Ensaio de Imunoadsorção Enzimática , Células Epiteliais/enzimologia , Humanos , Glândulas Mamárias Humanas/citologia , Camundongos , Transfecção
6.
Clin Transl Oncol ; 10(1): 30-4, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18208790

RESUMO

We are accumulating evidence to suggest that 17(th) century Renaissance foodways -largely based on the old "Mediterranean dietary traditions"- may provide new nutraceutical management strategies against HER2-positive breast cancer disease in the 21st century. Epidemiological and experimental studies begin to support the notion that "The Sacred Law of Salads" (i.e., "raw vegetables... plenty of generous (olive) oil") -originally proposed in 1614 by Giacomo Castelvetro in its book The Fruit, Herbs & Vegetables of Italy- might be considered the first (unintended) example of customised diets for breast cancer prevention based on individual genetic make-up (i.e., nutraceuticals against human breast carcinomas bearing HER2 oncogene amplification/overexpression). First, the so-called salad vegetables dietary pattern (i.e., a high consumption of raw vegetables and olive oil) appears to exert a protective effect mostly confined to the HER2-positive breast cancer subtype, with no significant influence on the occurrence of HER2-negative breast cancers. Second, all the main olive oil constituents (i.e., the omega-9 monounsaturated fatty acid oleic acid and polyphenolic compounds such as the secoiridoid oleuropein or the lignan 1-[+]-acetoxypinoresinol) dramatically reduce HER2 expression and specifically induce apoptotic cell death in cultured HER2- positive breast cancer cells, with marginal effects against HER2-negative cells. Third, an olive oil-rich diet negatively influences experimental mammary tumorigenesis in rats likewise decreasing HER2 expression levels. If early 1600s Castelvetro's salads can be used as dietary protocols capable to protecting women against biologically aggressive HER2-positive breast cancer subtypes is an intriguing prospect that warrants to be evaluated in human pilot studies in the future. Here, at least, we would like to recognise Giacomo Castelvetro as the father of modern nutritional genomics in oncology.


Assuntos
Neoplasias da Mama/prevenção & controle , Genes Supressores de Tumor , Genes erbB-2 , Óleos de Plantas/administração & dosagem , Verduras , Neoplasias da Mama/genética , Feminino , Humanos , Azeite de Oliva
7.
Clin. transl. oncol. (Print) ; 10(1): 30-34, ene. 2008.
Artigo em Inglês | IBECS | ID: ibc-123403

RESUMO

We are accumulating evidence to suggest that 17(th) century Renaissance foodways -largely based on the old "Mediterranean dietary traditions"- may provide new nutraceutical management strategies against HER2-positive breast cancer disease in the 21st century. Epidemiological and experimental studies begin to support the notion that "The Sacred Law of Salads" (i.e., "raw vegetables... plenty of generous (olive) oil") -originally proposed in 1614 by Giacomo Castelvetro in its book The Fruit, Herbs & Vegetables of Italy- might be considered the first (unintended) example of customised diets for breast cancer prevention based on individual genetic make-up (i.e., nutraceuticals against human breast carcinomas bearing HER2 oncogene amplification/overexpression). First, the so-called salad vegetables dietary pattern (i.e., a high consumption of raw vegetables and olive oil) appears to exert a protective effect mostly confined to the HER2-positive breast cancer subtype, with no significant influence on the occurrence of HER2-negative breast cancers. Second, all the main olive oil constituents (i.e., the omega-9 monounsaturated fatty acid oleic acid and polyphenolic compounds such as the secoiridoid oleuropein or the lignan 1-[+]-acetoxypinoresinol) dramatically reduce HER2 expression and specifically induce apoptotic cell death in cultured HER2- positive breast cancer cells, with marginal effects against HER2-negative cells. Third, an olive oil-rich diet negatively influences experimental mammary tumorigenesis in rats likewise decreasing HER2 expression levels. If early 1600s Castelvetro's salads can be used as dietary protocols capable to protecting women against biologically aggressive HER2-positive breast cancer subtypes is an intriguing prospect that warrants to be evaluated in human pilot studies in the future. Here, at least, we would like to recognise Giacomo Castelvetro as the father of modern nutritional genomics in oncology (AU)


Assuntos
Humanos , Feminino , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/prevenção & controle , Genes Supressores de Tumor , Genes erbB-2 , Óleos de Plantas/administração & dosagem , Óleos de Plantas/metabolismo , Verduras , Neoplasias da Mama/genética
8.
Rev Med Chir Soc Med Nat Iasi ; 112(4): 1115-9, 2008.
Artigo em Romano | MEDLINE | ID: mdl-20209797

RESUMO

UNLABELLED: Remote monitoring of chronic diseases can improve health outcomes and potentially lower health care costs. The high number of the patients, suffering of chronically diseases, who wish to stay at home rather then in a hospital increasing the need of homecare monitoring and have lead to a high demand of wearable medical devices. Also, extended patient monitoring during normal activity has become a very important target. MATERIAL AND METHOD: In this paper are presented the design of the wireless monitoring devices based on ultra low power circuits, high storage memory flash, bluetooth communication and the firmware for the management of the monitoring device. RESULTS: The monitoring device is built using an ultra low power microcontroller (MSP430 from Texas Instruments) that offers the advantage of high integration of some circuits. The custom made electronic boards used for biosignal acquisition are also included modules for storage device (SD/MMC card) with FAT32 file system and Bluetooth device for short-range communication used for data transmission between monitoring device and PC or PDA. CONCLUSION: The work was focused on design and implementation of an ultra low power wearable device able to acquire patient vital parameters, causing minimal discomfort and allowing high mobility. The proposed wireless device could be used as a warning system for monitoring during normal activity.


Assuntos
Doença Crônica , Monitorização Ambulatorial/instrumentação , Monitorização Ambulatorial/métodos , Redes de Comunicação de Computadores , Desenho de Equipamento , Humanos , Consulta Remota/instrumentação
9.
Clin. transl. oncol. (Print) ; 8(11): 812-820, nov. 2006. ilus
Artigo em Inglês | IBECS | ID: ibc-126238

RESUMO

BACKGROUND: Data derived from epidemiological and experimental studies suggest that alphalinolenic acid (ALA; 18:3n-3), the main omega-3 polyunsaturated fatty acid (PUFA) present in the Western diet, may have protective effects in breast cancer risk and metastatic progression. A recent pilot clinical trial assessing the effects of ALA-rich dietary flaxseed on tumor biological markers in postmenopausal patients with primary breast cancer demonstrated significant reductions in tumor growth and in HER2 (erbB-2) oncogene expression. HYPOTHESIS: The molecular mechanism by which ALA inhibits breast cancer cell growth and metastasis formation may involve a direct regulation of HER2, a well-characterized oncogene playing a key role in the etiology, progression and response to some chemo- and endocrine therapies in approximately 20% of breast carcinomas. METHODS: Using HER2-specific ELISA, flow cytometry, immunofluorescence microscopy, Western blotting, RT-PCR and HER2 promoter-reporter analyses, we characterized the effects of exogenous supplementation with ALA on the expression of HER2 oncogene, a master key player in the onset and metastasis formation of breast cancer disease. Metabolic status (MTT) assays were performed to evaluate the nature of the cytotoxic interaction between ALA and the humanized anti-HER2 monoclonal antibody trastuzumab (Herceptin). To study these issues we used BT-474 and SKBr-3 breast cancer cells, which naturally exhibit amplification of the HER2 oncogene. RESULTS: ALA treatment dramatically suppressed the expression of HER2-coded p185Her-2/neu oncoprotein as determined by ELISA, flow cytometry, immunofluorescence microscopy and immunoblotting techniques. Interestingly, ALA-induced down-regulation of p185Her-2/neu correlated with a transcriptional response as no HER2 mRNA signal could be detected by RT-PCR upon treatment with optimal concentrations of ALA (up to 20 microM). Consistent with these findings, ALA exposure was found to dramatically repress the activity of a Luciferase reporter gene driven by the HER2 promoter. Moreover, the nature of the cytotoxic interaction between ALA and trastuzumab (Herceptin) revealed a significant synergism as assessed by MTT-based cell viability assays. CONCLUSIONS: i) These findings reveal that the omega-3 PUFA ALA suppresses overexpression of HER2 oncogene at the transcriptional level, which, in turn, interacts synergistically with anti-HER2 trastuzumab- based immunotherapy. ii) Our results molecularly support a recent randomized double-blind placebo-controlled clinical trial suggesting that ALA may be a potential dietary alternative or adjunct to currently used drugs in the management of HER2-positive breast carcinomas. iii) Considering our previous findings demonstrating the <> of the omega-6 PUFA linolenic acid (LA; 18:2n-6) and the <> of the omega-3 PUFA docosahexaenoic acid (DHA; 22:6n-3) and of the omega-9 monounsaturated fatty acid oleic acid (OA; 18:1n-9), it is reasonable to suggest that a low omega-6/omega-3 PUFA ratio and elevated MUFA levels, the two prominent <> of the <>, should be extremely efficient at blocking HER2 expression in breast cancer cells (AU)


Assuntos
Humanos , Feminino , Anticorpos Monoclonais Humanizados , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/prevenção & controle , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/prevenção & controle , Genes erbB-2 , /antagonistas & inibidores , /biossíntese , Linhagem Celular Tumoral , Linhagem Celular Tumoral/metabolismo , Dieta Mediterrânea , Gorduras na Dieta , Ácidos Graxos , Indução Enzimática
11.
Ann Oncol ; 16(8): 1253-67, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15870086

RESUMO

BACKGROUND: Orlistat (Xenicaltrade mark), a US Food and Drug Administration (FDA)-approved drug for bodyweight loss, has recently been demonstrated to exhibit antitumor properties towards prostate cancer cells by virtue of its ability to block the lipogenic activity of fatty acid synthase (FAS). FAS (oncogenic antigen-519) is up-regulated in about 50% of breast cancers, is an indicator of poor prognosis, and has recently been functionally associated with the Her2/neu (erbB-2) oncogene. MATERIALS AND METHODS: We assessed the antitumoral effects of orlistat against the human breast cancer cell line SK-Br3, an in vitro paradigm of FAS and Her2/neu overexpression in breast cancer. RESULTS: Cell cycle analyses revealed that micromolar concentrations of orlistat induced, in a time- and dose-dependent manner, significant changes in the distribution of cell populations including a complete loss of G2-M phase, S-phase accumulation and a concomitant increase in the emerging sub-G1 (apoptotic) cells. Poly (ADP-ribose) polymerase (PARP) cleavage, an early event required for cells committed to apoptosis, was more predominant in orlistat-treated G1 phase cells. When we characterized signaling molecules participating in the cellular events following orlistat-induced inhibition of FAS activity and preceded inhibition of breast cancer cell proliferation, a dramatic down-regulation of Her2/neu-coded p185(Her2/neu) oncoprotein was found in orlistat-treated SK-Br3 cells (>90% reduction). Interestingly, a significant accumulation of the DNA-binding protein PEA3, a member of the Ets transcription factor family that specifically targets a PEA3-binding motif present on the Her2/neu gene promoter and down-regulates its activity, was observed in orlistat-treated SK-Br3 cells. When a Luciferase reporter gene driven by the Her2/neu promoter was transiently transfected in SK-Br3 cells, orlistat exposure was found to dramatically repress the promoter activity of Her2/neu gene, whereas a Her2/neu promoter bearing a mutated binding DNA sequence was not subject to negative regulation by orlistat, thus demonstrating that the intact PEA3 binding site on the Her2/neu promoter is required for the orlistat-induced transcriptional repression of Her2/neu overexpression. RNA interference (RNAi)-mediated silencing of FAS gene expression similarly repressed Her2/neu gene expression in a PEA3-dependent manner, thus ruling out a role for non-FAS orlistat-mediated effects. When the combination of orlistat and the anti-Her2/neu antibody trastuzumab (Herceptintrade mark) in either concurrent (orlistat + trastuzumab) or sequential (orlistat --> trastuzumab; trastuzumab --> orlistat) schedules was tested for synergism, addition or antagonism using the combination index (CI) method of Chou-Talalay, co-exposure of orlistat and trastuzumab demonstrated strong synergistic effects (CI10-90 = 0.110-0.847), whereas sequential exposure to orlistat followed by trastuzumab (CI10-90 = 0.380-1.210) and trastuzumab followed by orlistat (CI10-90 = 0.605-1.278) mainly showed additive or antagonistic interactions. Indeed, orlistat-induced FAS inhibition synergistically promoted apoptotic cell death when concurrently combined with trastuzumab as determined by an ELISA for histone-associated DNA fragments. Importantly, the degree of FAS expression in a panel of human breast cancer cell lines was predictive of sensitivity to orlistat-induced anti-proliferative effects as determined by a MTT-based characterization of metabolically viable breast cancer cells. Moreover, hypersensitivity to orlistat-induced cytotoxicity was observed in MCF-7 breast cancer cells engineered to overexpress Her2/neu (MCF-7/Her2-18 cells), which exhibit a significant up-regulation of FAS expression and activity. CONCLUSIONS: These findings reveal that the development of more potent and/or bioavailable orlistat's variants targeting the lipogenic activity of FAS may open a novel therapeutic avenue for treating Her2/neu-overexpressing breast carcinomas.


Assuntos
Fármacos Antiobesidade/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Lactonas/farmacologia , Receptor ErbB-2/metabolismo , Fatores de Transcrição/metabolismo , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados , Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Regulação para Baixo , Sinergismo Farmacológico , Quimioterapia Combinada , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Immunoblotting , Lipase/antagonistas & inibidores , Luciferases/metabolismo , Orlistate , Poli(ADP-Ribose) Polimerases/metabolismo , Regiões Promotoras Genéticas/genética , RNA Interferente Pequeno/farmacologia , Receptor ErbB-2/genética , Receptores do Fator de Necrose Tumoral/antagonistas & inibidores , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/metabolismo , Transcrição Gênica , Trastuzumab , Células Tumorais Cultivadas , Receptor fas
12.
Eur J Cancer Prev ; 14(3): 263-70, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15901996

RESUMO

Omega-3 polyunsaturated fatty acid (PUFA), docosahexaenoic acid (DHA; 22:6n-3) and other omega-3 and omega-6 PUFAs have raised interest as novel anticancer agents by exerting selective cytotoxic effects on human cancer cells without affecting normal tissues. Here, we examined the in vitro relationship between exogenous supplementation with DHA and breast cancer chemosensitivity to taxanes. We measured cell viability in the highly metastatic human breast cancer cell line MDA-MB-231 exposed sequentially to DHA followed by paclitaxel (Taxol) or docetaxel (Taxotere). As DHA by itself showed cytotoxic effects, possible synergistic interactions between DHA and taxanes were assessed, employing the combination index (CI) method and the isobologram analysis. Both methods showed a strong synergism (CI approximately 0.5; P<0.005) between DHA and taxanes in MDA-MB-231 cells. When the increase in taxanes efficacy was measured by dividing the IC50 values (50% inhibitory concentrations) obtained when the cells were exposed to taxanes alone by those after DHA pre-exposure, we found that DHA enhanced the cytotoxic activity of taxanes against MDA-MB-231 cells in a dose-dependent manner (up to 13- and 5-fold increase in Taxol and Taxotere efficacy, respectively). Importantly, sequential exposure to DHA followed by taxanes also yielded strong synergism in Her-2/neu (c-erbB-2)-overexpressing and taxanes-resistant SK-Br3 and BT-474 breast cancer cells. Moreover, exogenous supplementation with DHA significantly decreased the expression of Her-2/neu-codified p185(Her-2/neu) oncoprotein (up to 78% reduction in BT-474 cells). Our results provide experimental support to the hypothesis that omega-3 PUFAs can be used as modulators of tumor cell chemosensitivity and provide the rationale for in vivo preclinical investigation. In addition, this is the first study demonstrating that omega-3 PUFA DHA downregulates Her-2/neu oncogene expression in human breast cancer cells.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Ácidos Docosa-Hexaenoicos/farmacologia , Ácidos Graxos Ômega-3/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Receptor ErbB-2/biossíntese , Antineoplásicos Fitogênicos/toxicidade , Docetaxel , Relação Dose-Resposta a Droga , Regulação para Baixo , Feminino , Humanos , Paclitaxel/toxicidade , Taxoides/toxicidade , Células Tumorais Cultivadas
13.
Ann Oncol ; 16(3): 359-71, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15642702

RESUMO

BACKGROUND: The relationship between the intake of olive oil, the richest dietary source of the monounsaturated fatty acid oleic acid (OA; 18:1n-9), and breast cancer risk and progression has become a controversial issue. Moreover, it has been suggested that the protective effects of olive oil against breast cancer may be due to some other components of the oil rather than to a direct effect of OA. METHODS: Using flow cytometry, western blotting, immunofluorescence microscopy, metabolic status (MTT), soft-agar colony formation, enzymatic in situ labeling of apoptosis-induced DNA double-strand breaks (TUNEL assay analyses), and caspase-3-dependent poly-ADP ribose polymerase (PARP) cleavage assays, we characterized the effects of exogenous supplementation with OA on the expression of Her-2/neu oncogene, which plays an active role in breast cancer etiology and progression. In addition, we investigated the effects of OA on the efficacy of trastuzumab (Herceptin), a humanized monoclonal antibody binding with high affinity to the ectodomain of the Her-2/neu-coded p185(Her-2/neu) oncoprotein. To study these issues we used BT-474 and SKBr-3 breast cancer cells, which naturally exhibit amplification of the Her-2/neu oncogene. RESULTS: Flow cytometric analyses demonstrated a dramatic (up to 46%) reduction of cell surface-associated p185(Her-2/neu) following treatment of the Her-2/neu-overexpressors BT-474 and SK-Br3 with OA. Indeed, this effect was comparable to that found following exposure to optimal concentrations of trastuzumab (up to 48% reduction with 20 microg/ml trastuzumab). Remarkably, the concurrent exposure to OA and suboptimal concentrations of trastuzumab (5 microg/ml) synergistically down-regulated Her-2/neu expression, as determined by flow cytometry (up to 70% reduction), immunoblotting, and immunofluorescence microscopy studies. The nature of the cytotoxic interaction between OA and trastuzumab revealed a strong synergism, as assessed by MTT-based cell viability and anchorage-independent soft-agar colony formation assays. Moreover, OA co-exposure synergistically enhanced trastuzumab efficacy towards Her-2/neu overexpressors by promoting DNA fragmentation associated with apoptotic cell death, as confirmed by TUNEL and caspase-3-dependent PARP cleavage. In addition, treatment with OA and trastuzumab dramatically increased both the expression and the nuclear accumulation of p27(Kip1), a cyclin-dependent kinase inhibitor playing a key role in the onset and progression of Her-2/neu-related breast cancer. Finally, OA co-exposure significantly enhanced the ability of trastuzumab to inhibit signaling pathways downstream of Her-2/neu, including phosphoproteins such as AKT and MAPK. CONCLUSIONS: These findings demonstrate that OA, the main monounsaturated fatty acid of olive oil, suppresses Her-2/neu overexpression, which, in turn, interacts synergistically with anti-Her-2/neu immunotherapy by promoting apoptotic cell death of breast cancer cells with Her-2/neu oncogene amplification. This previously unrecognized property of OA offers a novel molecular mechanism by which individual fatty acids may regulate the malignant behavior of breast cancer cells and therefore be helpful in the design of future epidemiological studies and, eventually, dietary counseling.


Assuntos
Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ácido Oleico/farmacologia , Receptor ErbB-2/biossíntese , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados , Apoptose , Proliferação de Células , Gorduras na Dieta , Interações Medicamentosas , Feminino , Citometria de Fluxo , Humanos , Marcação In Situ das Extremidades Cortadas , Azeite de Oliva , Óleos de Plantas/química , Trastuzumab , Células Tumorais Cultivadas
14.
Rev Med Chir Soc Med Nat Iasi ; 109(2): 440-4, 2005.
Artigo em Romano | MEDLINE | ID: mdl-16607817

RESUMO

In many medical fields the recovery of muscular activity or its improvement up to the level of the optimal parameters is required. Apart from the classical solution for rehabilitation (physical exercises) the use of electrical stimulation has become quite frequent of late. The paper presents an interface that detects the electromyographic (EMG) activity, assesses it, and generates appropriate electrical stimuli, by means of a specific type of fuzzy control system, in order to control the dynamics of the EMG. The proposed interface will detect the motion and muscular activity, it will evaluate and generate the electrical stimulus using a fuzzy system tuned by dynamic of motion. The application will transmit e-Health information to the physician via Internet, synthetic, at request using TCP/IP stack and SMS services for wireless communication.


Assuntos
Serviços de Assistência Domiciliar , Internet , Monitorização Ambulatorial/instrumentação , Doenças Neuromusculares/reabilitação , Eletromiografia/métodos , Lógica Fuzzy , Humanos , Monitorização Ambulatorial/métodos , Interface Usuário-Computador
16.
Int J Oncol ; 23(5): 1407-12, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14532983

RESUMO

Black cohosh is an increasingly popular alternative to estrogen replacement therapy for the relief of menopausal symptoms, primarily hot flushes. However, an important consideration for long-term therapy is potential toxicity and carcinogenicity. Therefore, we undertook a study to assess the estrogenic activity of black cohosh to examine its safety for those with, or at high risk of developing, breast cancer. Several assays were utilized as listed: RNAse protection assays, which ascertain the regulation of the expression of E2-responsive genes; estrogen-responsive-element (ERE)-luciferase, which determines modulation of the ER function by transactivation of the ERE; the Ishikawa cell system, which has an E2-regulated endogenous alkaline phosphatase; and colony formation of ER-expressing breast cancer cells, which indicates possible progression of early stage breast cancer into a more aggressive state. Black cohosh extracts did not demonstrate estrogenic activity in any of these assay systems. This is an encouraging step in the assessment of the safety of black cohosh for treatment of menopausal hot flushes.


Assuntos
Neoplasias da Mama/patologia , Cimicifuga/metabolismo , Estrogênios/metabolismo , Menopausa/efeitos dos fármacos , Extratos Vegetais , Fosfatase Alcalina/metabolismo , Neoplasias da Mama/tratamento farmacológico , Adesão Celular , Divisão Celular , Linhagem Celular Tumoral , Humanos , RNA Mensageiro/metabolismo , Receptores de Estrogênio/metabolismo , Ribonucleases/metabolismo
17.
Endocr Relat Cancer ; 10(2): 141-52, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12790776

RESUMO

CYR61 (CNN1), a member of the cysteine rich 61/connective tissue growth factor/nephroblastoma overexpressed (CYR61/CTFG/NOV) family of growth regulators (CNN), is a pro-angiogenic factor that mediates diverse roles in development, cell proliferation, and tumorigenesis. We have recently shown that CYR61 is overexpressed in invasive and metastatic human breast cancer cells. Accordingly, elevated levels of CYR61 in breast cancer are associated with more advanced disease. Unfortunately, the exact mechanisms by which CYR61 promotes an aggressive breast cancer phenotype are still largely unknown. This review examines the functional role of CYR61 in breast cancer disease, presenting evidence that CYR61 signaling may play a major role in estrogen- as well as growth factor-dependent breast cancer progression. We also emphasize the functional significance of the molecular connection of CYR61 and its integrin receptor alpha(v)beta(3) enhancing breast cancer aggressiveness. Moreover, we describe experimental evidence that establishes a novel role for CYR61 determining the protection of human breast cancer cells against chemotherapy-induced apoptosis through its interactions with the integrin receptor alpha(v)beta(3). All these findings delineate a new noteworthy function of a CYR61/alpha(v)beta(3) autocrine-paracrine signaling pathway within both angiogenesis and breast cancer progression, which would allow a dual anti-angiogenic and anti-tumor benefit with a single drug.


Assuntos
Adenocarcinoma/metabolismo , Indutores da Angiogênese/fisiologia , Neoplasias da Mama/metabolismo , Proteínas Imediatamente Precoces/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Adenocarcinoma/patologia , Neoplasias da Mama/patologia , Adesão Celular/fisiologia , Divisão Celular/fisiologia , Movimento Celular/fisiologia , Proteína Rica em Cisteína 61 , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Invasividade Neoplásica , Neoplasias Hormônio-Dependentes/metabolismo , Neoplasias Hormônio-Dependentes/patologia
18.
Oncol Rep ; 8(6): 1203-14, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11605034

RESUMO

Heregulin (HRG) is one of the groups of polypeptide growth factors that activate the erbB-2 receptor via induction of heterodimerization with erbB-3 and erbB-4 receptors. The biological effects of HRG have been extensively studied. The vast majority of the reports indicate that HRG induces cell growth in breast cancer cells expressing normal levels of erbB-2 and growth inhibition and apoptosis in cells over-expressing erbB-2. However, the mechanism by which HRG promotes cell growth inhibition and apoptosis is still unknown. Previously we reported that constitutive expression of HRG in an erbB-2-overexpressing cell line (SKBr-3) induced growth arrest and apoptosis. We also demonstrated that constitutive expression of HRG promoted a marked morphological change, G2/M delay of the cell cycle, and DNA fragmentation. In this study, we demonstrate the mechanism by which HRG induces these cellular effects. The doubling time of the SK/HRG cells increased in relation to the level of HRG expression, and the level of HRG expression dictates the morphological change of the cells as well as their ability to grow or not grow in an anchorage-independent manner. We demonstrate that these effects are accompanied by downregulation of both erbB-2 and erbB-3 receptors at the transcriptional and translational levels and that down-regulation of the erbB-receptors results in reduced receptor tyrosine phosphorylation. The decrease in erbB-receptor phosphorylation in turn results in a marked reduction of ERK activity and a significant increase in JNK activity. Consequently, overexpression of HRG promoted the expression of PEA3, an Ets nuclear transcription factor. Taken together, our data demonstrate that the cellular effects induced by constitutive expression of HRG in SKBr-3 cells are correlated with the level of HRG expression. This is a first report demonstrating that HRG induction of apoptosis is directly correlated with decreased MAPK activity, increased JNK activity resulting in upregulation of PEA3 and down-regulation of the erbB-2 receptor. Overall, these data provide important clues regarding the mechanism and downstream molecules involved in HRG induction of apoptosis that can be used as targets for therapeutic prevention.


Assuntos
Apoptose/fisiologia , Regulação da Expressão Gênica/fisiologia , Proteínas Quinases JNK Ativadas por Mitógeno , Neuregulina-1/fisiologia , Receptor ErbB-2/fisiologia , Receptor ErbB-3/fisiologia , Transdução de Sinais/fisiologia , Animais , Ciclo Celular , Regulação para Baixo , Humanos , MAP Quinase Quinase 4 , Sistema de Sinalização das MAP Quinases/fisiologia , Quinases de Proteína Quinase Ativadas por Mitógeno , Proteínas Quinases Ativadas por Mitógeno , RNA Mensageiro , Fatores de Transcrição , Células Tumorais Cultivadas , Regulação para Cima
20.
Cancer Res ; 60(20): 5603-7, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11059746

RESUMO

We have previously shown that expression of heregulin (HRG) is closely correlated with breast cancer progression. We have subsequently isolated Cyr61, a ligand for the alpha(v)beta3 integrin that is differentially expressed in HRG-positive cells, and have shown that it is expressed in all of the invasive and metastatic breast cancer cell lines tested. Preliminary evaluation of Cyr61 expression in breast tumor biopsies revealed expression of Cyr61 in about 30% of invasive breast carcinomas. Significantly, we demonstrated that Cyr61 is a downstream effector of HRG action, because a Cyr61-neutralizing antibody abolished the ability of HRG-expressing cells to migrate in vitro. Furthermore, we have shown that HRG-expressing cells denote higher levels of alpha(v)beta3 expression, and we have established that Cyr61 action is mediated, at least in part, through its receptor alpha(v)beta3, because a functional blocking antibody of the alpha(v)beta3 blocked the Matrigel outgrowth of HRG-expressing cells. These results strongly suggest that Cyr61 is necessary for HRG-mediated chemomigration and that Cyr61 plays a functional role in breast cancer progression, possibly through its interactions with the alpha(v)beta3 receptor.


Assuntos
Indutores da Angiogênese/fisiologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Substâncias de Crescimento/fisiologia , Proteínas Imediatamente Precoces/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular , Indutores da Angiogênese/biossíntese , Indutores da Angiogênese/metabolismo , Anticorpos/farmacologia , Biópsia , Movimento Celular/fisiologia , Proteína Rica em Cisteína 61 , Progressão da Doença , Substâncias de Crescimento/biossíntese , Substâncias de Crescimento/metabolismo , Humanos , Proteínas Imediatamente Precoces/biossíntese , Proteínas Imediatamente Precoces/metabolismo , Metástase Neoplásica , Neuregulina-1/biossíntese , Receptores de Estrogênio/biossíntese , Receptores de Vitronectina/metabolismo , Células Tumorais Cultivadas
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