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1.
Invest New Drugs ; 38(1): 10-19, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30887252

RESUMO

In this study, we assess arginine auxotrophy in ovarian cancer cells and attempt to target them using arginine deprivation induced by a pegylated recombinant human Arginase I cobalt [HuArgI (Co)-PEG5000]. Ovarian cancer cells were sensitive to [HuArgI (Co)-PEG5000]-induced arginine deprivation with IC50 values in the low pM range. Addition of excess L-citrulline rescued only one of three cell lines tested, indicating that the majority of cell lines are completely auxotrophic for arginine. The expression pattern of argininosuccinate synthetase (ASS1) confirmed the degree of auxotrophy of ovarian cancer cell lines with completely auxotrophic cells not expressing ASS1 and partially auxotrophic cells expressing the enzyme. Ovarian cancer cell lines were negative for annexinV staining while showing loss of membrane integrity and absence of caspase activation, indicating caspase-independent, non-apoptotic cell death. [HuArgI (Co)-PEG5000]-induced arginine deprivation led to extensive and prolonged activation of autophagy, which proved to be deleterious to cell survival since its inhibition led to a significant decrease in cytotoxicity. This indicates that the activation of autophagy following arginine-deprivation, rather than being protective, mediates cell cytotoxicity leading to death by autophagy.


Assuntos
Arginase/administração & dosagem , Arginina/deficiência , Autofagia , Neoplasias Ovarianas/patologia , Polietilenoglicóis/administração & dosagem , Apoptose , Arginase/química , Proliferação de Células , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Polietilenoglicóis/química , Células Tumorais Cultivadas
2.
Cancer Cell Int ; 20: 150, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32390765

RESUMO

Arginine is a semi essential amino acid that is used in protein biosynthesis. It can be obtained from daily food intake or synthesized in the body through the urea cycle using l-citrulline as a substrate. Arginine has a versatile role in the body because it helps in cell division, wound healing, ammonia disposal, immune system, and hormone biosynthesis. It is noteworthy that l-arginine is the precursor for the biosynthesis of nitric oxide (NO) and polyamines. In the case of cancer cells, arginine de novo synthesis is not enough to compensate for their high nutritional needs, forcing them to rely on extracellular supply of arginine. In this review, we will go through the importance of arginine deprivation as a novel targeting therapy by discussing the different arginine deprivation agents and their mechanism of action. We will also focus on the factors that affect cell migration and on the influence of arginine on metastases through polyamine and NO.

3.
Cell Commun Signal ; 18(1): 144, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32900380

RESUMO

BACKGROUND: Lung cancer is the second most commonly occurring cancer. The ability to metastasize and spread to distant locations renders the tumor more aggressive. Members of the Rho subfamily of small GTP-binding proteins (GTPases) play a central role in the regulation of the actin cytoskeleton and in cancer cell migration and metastasis. In this study we investigated the role of the RhoA/Cdc42 GAP, StarD13, a previously described tumor suppressor, in malignancy, migration and invasion of the lung cancer cells A549. METHODS: We knocked down StarD13 expression in A549 lung cancer cells and tested the effect on cell migration and invadopodia formation using time lapse imaging and invasion assays. We also performed rescue experiments to determine the signaling pathways downstream of StarD13 and transfected the cells with FRET biosensors for RhoGTPases to identify the proteins involved in invadopodia formation. RESULTS: We observed a decrease in the level of expression of StarD13 in lung tumor tissues compared to normal lung tissues through immunohistochemistry. StarD13 also showed a lower expression in the lung adenocarcinoma cell line A549 compared to normal lung cells, WI38. In addition, the depletion of StarD13 increased cell proliferation and viability in WI38 and A549 cells, suggesting that StarD13 might potentially be a tumor suppressor in lung cancer. The depletion of StarD13, however, inhibited cell motility, conversely demonstrating a positive regulatory role in cell migration. This was potentially due to the constitutive activation of RhoA detected by pull down and FRET assays. Surprisingly, StarD13 suppressed cell invasion by inhibiting Cdc42-mediated invadopodia formation. Indeed, TKS4 staining and invadopodia assay revealed that StarD13 depletion increased Cdc42 activation as well as invadopodia formation and matrix degradation. Normal lung cells depleted of StarD13 also produced invadopodia, otherwise a unique hallmark of invasive cancer cells. Cdc42 knock down mimicked the effects of StarD13, while overexpression of a constitutively active Cdc42 mimicked the effects of its depletion. Finally, immunostaining and FRET analysis revealed the absence of StarD13 in invadopodia as compared to Cdc42, which was activated in invadopodia at the sites of matrix degradation. CONCLUSION: In conclusion, StarD13 plays distinct roles in lung cancer cell migration and invasion through its differential regulation of Rho GTPases. Video abstract.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Neoplasias Pulmonares/metabolismo , Podossomos/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Células A549 , Adenocarcinoma de Pulmão/patologia , Movimento Celular , Humanos , Neoplasias Pulmonares/patologia , Invasividade Neoplásica/patologia , Podossomos/patologia
4.
J Mammary Gland Biol Neoplasia ; 24(1): 17-38, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30194659

RESUMO

Connexins (Cxs), the building blocks of gap junctions (GJs), exhibit spatiotemporal patterns of expression and regulate the development and differentiation of the mammary gland, acting via channel-dependent and channel-independent mechanisms. Impaired Cx expression and localization are reported in breast cancer, suggesting a tumor suppressive role for Cxs. The signaling events that mediate the role of GJs in the development and tumorigenesis of the mammary gland remain poorly identified. The Wnt pathways, encompassing the canonical or the Wnt/ß-catenin pathway and the noncanonical ß-catenin-independent pathway, also play important roles in those processes. Indeed, aberrant Wnt signaling is associated with breast cancer. Despite the coincident roles of Cxs and Wnt pathways, the cross-talk in the breast tissue is poorly defined, although this is reported in a number of other tissues. Our previous studies revealed a channel-independent role for Cx43 in inducing differentiation or suppressing tumorigenesis of mammary epithelial cells by acting as a negative regulator of the Wnt/ß-catenin pathway. Here, we provide a brief overview of mammary gland development, with emphasis on the role of Cxs in development and tumorigenesis of this tissue. We also discuss the role of Wnt signaling in similar contexts, and review the literature illustrating interplay between Cxs and Wnt pathways.


Assuntos
Neoplasias da Mama/patologia , Carcinogênese/patologia , Junções Comunicantes/patologia , Glândulas Mamárias Animais/patologia , Glândulas Mamárias Humanas/patologia , Via de Sinalização Wnt , Animais , Conexinas/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/crescimento & desenvolvimento , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/crescimento & desenvolvimento , beta Catenina/metabolismo
5.
Int J Mol Sci ; 20(23)2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31795337

RESUMO

PURPOSE: Colorectal cancer (CRC) is the third most common type of cancer worldwide, and it represents over half of all gastrointestinal cancer deaths. Knowing that cancer cells have a high proliferation rate, they require high amounts of amino acids, including arginine. In addition, several tumor types have been shown to downregulate ASS-1 expression, becoming auxotrophic for arginine. Therefore, Arginine deprivation is one of the promising therapeutic approaches to target cancer cells. This can be achieved through the use of a recombinant human arginase, HuArgI(Co)-PEG5000, an arginine degrading enzyme. METHODS: In this present study, the cytotoxic effect of HuArgI(Co)-PEG5000 on CRC cell lines (HT-29, Caco-2, Sw837) is examined though cytotoxicity assays. Wound healing assays, invasion assays, and adhesion assays were also performed to detect the effect on metastasis. RESULTS: Wound healing and invasion assays revealed a decrease in cell migration and invasion after treatment with arginase. Cells that were treated with arginase also showed a decrease in adhesion, which coincided with a decrease in RhoA activation, demonstrated though the use of a FRET biosensor to detect RhoA activation in a single cell assay, and a decrease in MMP-9 expression. Treating cells with both arginase and L-citrulline, which significantly restores intracellular arginine levels, reversed the effect of HuArgI(Co)-PEG5000 on cell viability, migration, and invasion. CONCLUSION: We can, therefore, conclude that colorectal cancer is partially auxotrophic to arginine and that arginine depletion is a potential selective inhibitory approach for motility and invasion in colon cancer cells.


Assuntos
Antineoplásicos/farmacologia , Arginase/farmacologia , Arginina/metabolismo , Neoplasias Colorretais/tratamento farmacológico , Invasividade Neoplásica/prevenção & controle , Polietilenoglicóis/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Humanos , Invasividade Neoplásica/patologia
6.
BMC Complement Altern Med ; 17(1): 36, 2017 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-28073348

RESUMO

BACKGROUND: Previous studies in our laboratory showed that the Lebanese Daucus carota ssp. carota (wild carrot) oil extract possesses in vitro and in vivo anticancer activities. The present study aims to examine the cytotoxic effect of Daucus carota oil fractions on human epidermal keratinocytes and evaluate the chemopreventive activity of the pentane diethyl ether fraction on DMBA/TPA induced skin carcinogenesis in mice. METHODS: Wild carrot oil extract was chromatographed to yield four fractions (F1, 100% pentane; F2, 50:50 pentane:diethyl ether; F3, 100% diethyl ether; F4 93:7 chloroform:methanol). The cytotoxic effect of fractions (10, 25, 50 and 100 µg/mL) was tested on human epidermal keratinocytes (non-tumorigenic HaCaT cells and tumorigenic HaCaT-ras variants) using WST a ssay. Cell cycle phase distribution of tumorigenic HaCaT-ras variants was determined by flow cytometry post-treatment with F2 fraction. Apoptosis related proteins were also assessed using western blot. The antitumor activity of F2 fraction was also evaluated using a DMBA/TPA induced skin carcinoma in Balb/c mice. RESULTS: All fractions exhibited significant cytotoxicity, with HaCaT cells being 2.4-3 times less sensitive than HaCaT-ras A5 (benign tumorigenic), and HaCaT-ras II4 (malignant) cells. GC-MS analysis revealed the presence of a major compound (around 60%) in the pentane/diethylether fraction (F2), identified as 2-himachalen-6-ol. Treatment of HaCaT-ras A5 and HaCaT-ras II4 cells with F2 fraction resulted in the accumulation of cells in the sub-G1 apoptotic phase and decreased the population of cells in the S and G2/M phases. Additionally, F2 fraction treatment caused an up-regulation of the expression of pro-apoptotic (Bax) and down-regulation of the expression of anti-apoptotic (Bcl2) proteins. A decrease in the phosphorylation of AKT and ERK was also observed. Intraperitoneal treatment with F2 fraction (50 or 200 mg/kg) in the DMBA/TPA skin carcinogenesis mouse model showed a significant inhibition of papilloma incidence (mice with papilloma), yield (number of papilloma/mouse) and volume (tumor relative size) at weeks 15, 18 and 21. CONCLUSION: The present data reveal that F2 fraction has a remarkable antitumor activity against DMBA/TPA-induced skin carcinogenesis, an effect that may be mediated through inhibition of the MAPK/ERK and PI3K/AKT pathways.


Assuntos
Proliferação de Células/efeitos dos fármacos , Daucus carota/química , Queratinócitos/citologia , Substâncias Protetoras/administração & dosagem , Neoplasias Cutâneas/prevenção & controle , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Apoptose/efeitos dos fármacos , Ciclina D1/genética , Ciclina D1/metabolismo , Fase G1/efeitos dos fármacos , Humanos , Queratinócitos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/fisiopatologia , Acetato de Tetradecanoilforbol/toxicidade , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
7.
J Neurooncol ; 122(1): 75-85, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25567351

RESUMO

In this study, we attempt to target Arginine auxotrophy in glioblastoma multiforme (GBM) cells using a pegylated recombinant human Arginase I cobalt [HuArgI (Co)-PEG5000]. We tested and characterized the activity of HuArgI (Co)-PEG5000 on a panel of 9 GBM cell lines and on human fetal glial cells (SVG-p12). HuArgI (Co)-PEG5000 was cytotoxic to all GBM cells tested. SVG-p12 cells were not sensitive demonstrating the selective cytotoxicity of HuArgI (Co)-PEG5000-induced arginine deprivation. Addition of L-citrulline led to the rescue of 6 GBM cell lines but only at concentrations of 11.4 mM, reflecting the extent of arginine auxotrophy in GBM. The ability of L-citrulline to rescue cells was dependent on the expression of argininosuccinate synthetase-1 (ASS1) with the cells that were not rescued by L-citrulline being negative for ASS1 expression. Knocking-down ASS1 reversed the ability of L-citrulline to rescue GBM cells, further illustrating the dependence of arginine auxotrophy on ASS1 expression. Inhibition of autophagy increased cell sensitivity to HuArgI (Co)-PEG5000 indicating that, following arginine deprivation, autophagy plays a protective role in GBM cells. Analysis of the type of cell death revealed a lack of AnnexinV staining and caspase activation in HuArgI (Co)-PEG5000-treated cells, indicating that arginine deprivation induces caspase-independent, non-apoptotic cell death in GBM. We have shown that GBM cells are auxotrophic for arginine and can be selectively targeted using HuArgI (Co)-PEG5000-induced arginine depletion, thus demonstrating that L-Arginine deprivation is a potent and selective potential treatment for GBM.


Assuntos
Apoptose/efeitos dos fármacos , Arginase/farmacologia , Arginina/metabolismo , Glioblastoma/patologia , Polietilenoglicóis/farmacologia , Argininossuccinato Sintase/antagonistas & inibidores , Argininossuccinato Sintase/metabolismo , Autofagia , Western Blotting , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citometria de Fluxo , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Humanos , Proteínas Recombinantes/metabolismo , Células Tumorais Cultivadas
8.
Exp Cell Res ; 321(2): 109-22, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24333506

RESUMO

Malignant astrocytomas are highly invasive into adjacent and distant regions of the normal brain. Rho GTPases are small monomeric G proteins that play important roles in cytoskeleton rearrangement, cell motility, and tumor invasion. In the present study, we show that the knock down of StarD13, a GTPase activating protein (GAP) for RhoA and Cdc42, inhibits astrocytoma cell migration through modulating focal adhesion dynamics and cell adhesion. This effect is mediated by the resulting constitutive activation of RhoA and the subsequent indirect inhibition of Rac. Using Total Internal Reflection Fluorescence (TIRF)-based Förster Resonance Energy Transfer (FRET), we show that RhoA activity localizes with focal adhesions at the basal surface of astrocytoma cells. Moreover, the knock down of StarD13 inhibits the cycling of RhoA activation at the rear edge of cells, which makes them defective in retracting their tail. This study highlights the importance of the regulation of RhoA activity in focal adhesions of astrocytoma cells and establishes StarD13 as a GAP playing a major role in this process.


Assuntos
Astrocitoma/patologia , Movimento Celular , Adesões Focais/metabolismo , Proteínas Supressoras de Tumor/fisiologia , Proteína rhoA de Ligação ao GTP/metabolismo , Astrocitoma/genética , Astrocitoma/metabolismo , Adesão Celular/efeitos dos fármacos , Adesão Celular/genética , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Adesões Focais/efeitos dos fármacos , Adesões Focais/genética , Proteínas Ativadoras de GTPase , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , RNA Interferente Pequeno/farmacologia , Distribuição Tecidual/efeitos dos fármacos , Distribuição Tecidual/genética , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor/antagonistas & inibidores , Proteína rhoA de Ligação ao GTP/antagonistas & inibidores , Proteína rhoA de Ligação ao GTP/genética
9.
Pharm Biol ; 53(9): 1285-94, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25856705

RESUMO

CONTEXT: Wild carrot, Daucus carota L. ssp. carota (Apiacae), is widely distributed throughout the world and has various uses in traditional medicine in Lebanon. OBJECTIVE: The present study aimed to fractionate and analyze the chemical composition of the Daucus carota oil extract (DCOE) fractions and to evaluate their antioxidant and hepatoprotective properties in vitro and in vivo. MATERIALS AND METHODS: DCOE was chromatographed on silica gel column to produce four fractions: pentane (F1), 50:50 pentane:diethyl ether (F2), diethyl ether (F3), and 93:7 chloroform: methanol (F4). Qualitative and quantitative analyses of oil fractions were performed by GC-MS and HPLC techniques. The in vitro antioxidant properties were assessed using DPPH, FIC, and ferric-reducing antioxidant power (FRAP) assays. The hepatoprotective property was determined by examining the levels of serum markers (alanine transaminase (ALT) and aspartate transaminase (AST)) and hepatic antioxidant (superoxide dismutase (SOD), catalase (CAT), and glutathione-S-transferase (GST)) enzymes in CCl4-intoxicated mice pretreated with intraperitoenal 50, 100, or 200 mg/kg b.w. of the oil fractions for 5 d. RESULTS: GCMS analysis of F2 revealed the presence of 2-himachalen-6-ol (61.4%) which is reported for the first time in Daucus carota species. F3 and F4 were rich in phenolics and flavonoids and demonstrated significant DPPH activity (IC50 = 0.29 and 0.38 mg/ml, respectively) and high FRAP values (225.11 and 437.59 µmol FeSO4/g, respectively). The sesquiterpene-rich fraction F1 had the highest FIC ability (IC50 = 0.28 mg/ml). Pretreatment with F1 and F4 reversed the CCl4-induced decrease in SOD, CAT, and GST levels and reduced significantly hepatic damage. DISCUSSION AND CONCLUSION: The current results suggested that wild carrot oil fractions exhibited a unique chemical composition and possessed significant antioxidant activities as well as hepatoprotective effects against CCl4-induced hepatotoxicity.


Assuntos
Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Daucus carota , Fígado/efeitos dos fármacos , Extratos Vegetais/farmacologia , Óleos de Plantas/farmacologia , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Biomarcadores/sangue , Compostos de Bifenilo/química , Tetracloreto de Carbono , Fracionamento Químico , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/patologia , Cromatografia Líquida de Alta Pressão , Citoproteção , Daucus carota/química , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Enzimas/sangue , Cromatografia Gasosa-Espectrometria de Massas , Fígado/enzimologia , Fígado/patologia , Camundongos Endogâmicos BALB C , Oxirredução , Fitoterapia , Picratos/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Óleos de Plantas/química , Óleos de Plantas/isolamento & purificação , Plantas Medicinais
10.
Chemotherapy ; 60(5-6): 302-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-26088465

RESUMO

Daucus carota (DC) is a herb used in folklore medicine in Lebanon to treat numerous diseases including cancer. Recent studies in our laboratory on DC oil and its fractions revealed potent anticancer activities in vitro and in vivo. The present study aims to investigate the effect of the most potent DC fraction, pentane/diethyl ether (50:50), on lung, skin, breast and glioblastoma cancer cell motility and invasion. Upon treatment, a pronounced decrease in cancer cell motility was observed in the 4 cell lines. The treatment also led to a decrease in cancer cell invasion and an increased cell adhesion. Additionally, the DC fraction caused a decrease in the activation of the ρ-GTPases Rac and CDC42, a finding that may partially explain the treatment-induced decrease in cell motility. The current study demonstrates a crucial effect of the DC pentane/diethyl ether fraction on cancer cell motility and metastasis, making it a potential candidate for cancer therapy specifically targeting cancer motility and metastasis.


Assuntos
Movimento Celular/efeitos dos fármacos , Daucus carota , Éter/uso terapêutico , Invasividade Neoplásica/prevenção & controle , Pentanos/uso terapêutico , Extratos Vegetais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Éter/isolamento & purificação , Éter/farmacologia , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Melanoma Experimental , Invasividade Neoplásica/patologia , Pentanos/isolamento & purificação , Pentanos/farmacologia , Extratos Vegetais/isolamento & purificação , Folhas de Planta , Óleos de Plantas/isolamento & purificação , Óleos de Plantas/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia
11.
BMC Complement Altern Med ; 14: 387, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25300932

RESUMO

BACKGROUND: Daucus carota L.ssp.carota (wild carrot), an herb used in folk medicine worldwide, was recently demonstrated to exhibit anticancer activity. In this study we examined the anticancer effect of Daucus carota oil extract (DCOE) fractions on the human breast adenocarcinoma cell lines MDA-MB-231 and MCF-7 and clarified the mechanism of action. METHODS AND RESULTS: Using the WST assay, the pentane fraction (F1) and 1:1 pentane:diethyl ether fraction (F2) were shown to possess the highest cytotoxicity against both cell lines. Flow cytometric analysis revealed that both fractions induced the accumulation of cells in the sub-G1 phase, increase in apoptotic cell death and chromatin condensation. The increase in apoptosis in response to treatment was also apparent in the increase in BAX and the decrease in Bcl-2 levels as well as the proteolytic cleavage of both caspase-3 and PARP as revealed by Western blot. Furthermore, treatment of MDA-MB-231 cells with either fraction significantly reduced the level of phosphorylated Erk but did not show any effect on phosphorylated Akt. The combined treatment with a potent PI3K inhibitor (wortmannin) and F1 or F2 fraction had a synergistic inhibitory effect on cell survival which shows that these two drugs work on different pathways. CONCLUSIONS: These results suggest that the pentane-based fractions of DCOE possess potential anti-cancer activity that is mainly mediated through the Erk pathway.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/fisiopatologia , Ciclo Celular/efeitos dos fármacos , Daucus carota/química , Extratos Vegetais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Pentanos , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo
12.
J Recept Signal Transduct Res ; 33(1): 10-3, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23316797

RESUMO

RhoGTPases are defined as a family of 20 small G proteins playing important roles in almost every cellular process. RhoGTPases are guanine nucleotide-binding proteins existing in two forms: the active form which is GTP bound and the inactive one that being GDP bound. RhoGTPase-activating proteins known as RhoGAPs constitute one of the major classes of regulators of RhoGTPases. They act as negative regulators of the RhoGTPases by enhancing their slow intrinsic GTPase activity. STARD13, a GTPase activating protein (GAP) for RhoGTPases, has been described as a tumor suppressor in hepatocellular carcinoma. In the present review, we discuss the family of RhoGTPases, their regulation and their RhoGAPs, focusing mainly on STARD13.


Assuntos
Proteínas Ativadoras de GTPase/metabolismo , Transdução de Sinais/fisiologia , Proteínas Supressoras de Tumor/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Ativação Enzimática , Humanos
13.
Phytother Res ; 27(5): 737-44, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22815230

RESUMO

Daucus carota L. ssp. carota (Apiacea) is used in traditional medicine in Lebanon and in different regions throughout the world. The present study investigates the in vitro anticancer activities of Daucus carota oil extract (DCOE) on four human cancer cell lines as well as its in vitro antioxidant activity. DCOE was extracted from the dried umbels with 50:50 acetone-methanol. The oil extract was analyzed by gas chromatography-mass spectrometry and screened for its antioxidant properties in vitro using 1,1-diphenyl-2-picryl hydrazyl free radical scavenging assay (DPPH), ferrous ion chelating assay (FIC) and the ferric reducing antioxidant power assay (FRAP). The anticancer activity of the oil extract against human colon (HT-29, Caco-2) and breast (MCF-7, MDA-MB-231) cancer cell lines was evaluated using the trypan blue exclusion method and the WST-1 cell proliferation assay. DCOE exhibited antioxidant activity in all assays used. The FRAP value was 164 ± 5.5 µmol FeSO4 /g, and the IC50 values for DPPH and FIC assays were 2.1 ± 0.03 mg/ml and 0.43 ± 0.02 mg/ml, respectively. Also, DCOE demonstrated a significant increase in cell death and decrease in cell proliferation. The effect of DCOE on the cell lines exhibited time and dose-dependent responses. The present study established that DCOE possesses both antioxidant and promising anticancer activities.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Daucus carota/química , Extratos Vegetais/farmacologia , Antineoplásicos Fitogênicos/química , Antioxidantes/química , Morte Celular , Linhagem Celular Tumoral , Proliferação de Células , Flavonoides/análise , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Fenóis/análise , Extratos Vegetais/química
14.
Int J Oncol ; 62(2)2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36579669

RESUMO

Genetic alterations drive tumor onset and progression. However, the cross­talk between tumor cells and the benign components of the surrounding stroma can also promote the initiation, progression and metastasis of solid tumors. These cellular and non­cellular stromal components form the tumor microenvironment (TME), which co­evolves with tumor cells. Their dynamic and mutualistic interactions are currently considered to be among the distinctive hallmarks of cancer. Biochemical and physical cues from the TME serve an essential role in regulating tumor onset and progression. They are also associated with resistance to treatment and poor prognosis in patients with cancer. Therefore, a deep understanding of the TME is vital for developing potent anticancer therapeutics and improving patient outcomes. The present review aims to review the biology of both cellular and non­cellular constituents of the TME and novel findings regarding their contribution to core as well as emerging cancer hallmarks. The present review also describes key TME markers that are either targeted in interventional clinical trials or serve as promising potential anticancer therapies. Understanding TME components and their intercellular interactions is key toward identifying the mechanisms of progression and treatment resistance. Such understanding is of utmost significance for personalized and effective cancer therapy strategies.


Assuntos
Neoplasias , Microambiente Tumoral , Humanos , Microambiente Tumoral/genética , Neoplasias/patologia
15.
Oncol Lett ; 25(2): 46, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36644133

RESUMO

Glioblastoma, also referred to as glioblastoma multiforme (GBM), is grade IV astrocytoma characterized by being fast-growing and the most aggressive brain tumor. In adults, it is the most prevalent type of malignant brain tumor. Despite the advancements in both diagnosis tools and therapeutic treatments, GBM is still associated with poor survival rate without any statistically significant improvement in the past three decades. Patient's genome signature is one of the key factors causing the development of this tumor, in addition to previous radiation exposure and other environmental factors. Researchers have identified genomic and subsequent molecular alterations affecting core pathways that trigger the malignant phenotype of this tumor. Targeting intrinsically altered molecules and pathways is seen as a novel avenue in GBM treatment. The present review shed light on signaling pathways and intrinsically altered molecules implicated in GBM development. It discussed the main challenges impeding successful GBM treatment, such as the blood brain barrier and tumor microenvironment (TME), the plasticity and heterogeneity of both GBM and TME and the glioblastoma stem cells. The present review also presented current advancements in GBM molecular targeted therapy in clinical trials. Profound and comprehensive understanding of molecular participants opens doors for innovative, more targeted and personalized GBM therapeutic modalities.

16.
J Neurooncol ; 108(3): 333-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22528793

RESUMO

Gliomas are the most common type of malignant primary brain tumor in humans, accounting for 80 % of malignant cases. Expression and activity of Rho GTPases, which coordinate several cellular processes including cell-cycle progression and cell migration, are commonly altered in many types of primary brain tumor. Here we review the suggested effects of deregulated Rho GTPase signaling on brain tumor malignancy, highlighting the controversy in the field. For instance, whereas expression of RhoA and RhoB has been found to be significantly reduced in astrocytic tumors, other studies have reported Rho-dependent LPA-induced migration in glioma cells. Moreover, whereas the Rac1 expression level has been found to be reduced in astrocytic tumor, it was overexpressed and induced invasion in medulloblastoma tumors. In addition to the Rho GTPases themselves, several of their downstream effectors (including ROCK, mDia, and N-WASP) and upstream regulators (including GEFs, GAPs, PI3K, and PTEN) have also been implicated in primary brain tumors.


Assuntos
Neoplasias Encefálicas/enzimologia , Neoplasias Encefálicas/patologia , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Humanos , Invasividade Neoplásica
17.
Proc Natl Acad Sci U S A ; 106(48): 20258-63, 2009 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19915146

RESUMO

We previously proposed a model of Class IA PI3K regulation in which p85 inhibition of p110alpha requires (i) an inhibitory contact between the p85 nSH2 domain and the p110alpha helical domain, and (ii) a contact between the p85 nSH2 and iSH2 domains that orients the nSH2 so as to inhibit p110alpha. We proposed that oncogenic truncations of p85 fail to inhibit p110 due to a loss of the iSH2-nSH2 contact. However, we now find that within the context of a minimal regulatory fragment of p85 (the nSH2-iSH2 fragment, termed p85ni), the nSH2 domain rotates much more freely (tau(c) approximately 12.7 ns) than it could if it were interacting rigidly with the iSH2 domain. These data are not compatible with our previous model. We therefore tested an alternative model in which oncogenic p85 truncations destabilize an interface between the p110alpha C2 domain (residue N345) and the p85 iSH2 domain (residues D560 and N564). p85ni-D560K/N564K shows reduced inhibition of p110alpha, similar to the truncated p85ni-572(STOP). Conversely, wild-type p85ni poorly inhibits p110alphaN345K. Strikingly, the p110alphaN345K mutant is inhibited to the same extent by the wild-type or truncated p85ni, suggesting that mutation of p110alpha-N345 is not additive with the p85ni-572(STOP) mutation. Similarly, the D560K/N564K mutation is not additive with the p85ni-572(STOP) mutant for downstream signaling or cellular transformation. Thus, our data suggests that mutations at the C2-iSH2 domain contact and truncations of the iSH2 domain, which are found in human tumors, both act by disrupting the C2-iSH2 domain interface.


Assuntos
Fosfatidilinositol 3-Quinases/metabolismo , Estrutura Terciária de Proteína/genética , Transdução de Sinais/fisiologia , Análise de Variância , Animais , Western Blotting , Linhagem Celular , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Camundongos , Modelos Biológicos , Mutação/genética , Fosfatidilinositol 3-Quinases/genética , Transdução de Sinais/genética
19.
Mycopathologia ; 174(2): 107-19, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22391823

RESUMO

Candida albicans is a common opportunistic pathogen that causes a wide variety of diseases in a human immunocompromised host leading to death. In a pathogen, cell wall proteins are important for stability as well as for acting as antigenic determinants and virulence factors. Pir32 is a cell wall protein and member of the Pir protein family previously shown to be upregulated in response to macrophage contact and whose other member, Pir1, was found to be necessary for cell wall rigidity. The purpose of this study is to characterize Pir32 by generating a homozygous null strain and comparing the phenotype of the null with that of the wild-type parental strain as far as filamentation, virulence in a mouse model of disseminated candidiasis, resistance to oxidative stress and cell wall disrupting agents, in addition to adhesion, biofilm capacities, and cell wall chitin content. Our mutant was shown to be hyperfilamentous, resistant to sodium dodecyl sulfate, hydrogen peroxide, sodium chloride, and more virulent in a mouse model when compared to the wild type. These results were unexpected, considering that most cell wall mutations weaken the wall and render it more susceptible to external stress factors and suggests the possibility of a cell surface compensatory mechanism. As such, we measured cell wall chitin deposition and found a twofold increase in the mutant, possibly explaining the above-observed phenotypes.


Assuntos
Candida albicans/fisiologia , Parede Celular/metabolismo , Quitina/metabolismo , Proteínas Fúngicas/genética , Deleção de Genes , Estresse Fisiológico , Animais , Candida albicans/citologia , Candida albicans/metabolismo , Candida albicans/patogenicidade , Candidíase/microbiologia , Candidíase/patologia , Modelos Animais de Doenças , Peróxido de Hidrogênio/toxicidade , Camundongos , Camundongos Endogâmicos BALB C , Viabilidade Microbiana/efeitos dos fármacos , Microscopia , Pressão Osmótica , Estresse Oxidativo , Cloreto de Sódio/metabolismo , Dodecilsulfato de Sódio/toxicidade , Virulência
20.
Oncol Rep ; 48(5)2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36102321

RESUMO

Cancer still ranks as one of the top causes of morbidity and mortality despite recent improvements in standard chemotherapy, radiotherapy, and surgery. This underlines some of the difficulties in creating successful therapeutic strategies, but it also highlights the shortcomings of conventional methods. In order to enhance the standard treatment of cancer patients, biology­driven therapies are emerging towards more specific and effective clinical options. In the present review, both conventional and novel methods for cancer treatment were addressed, with a particular focus on Glioblastoma multiforme (GBM) therapies. GBM is one of the most challenging cancers for conventional treatments, and survival rates of patients remain very low. In the present review, focus was addressed on employed chemo­ and radiotherapies along with developing novel targeted and immunotherapies assessed in clinical trials on patients with GBM or yet to be evaluated clinically. It was aimed to evaluate efficiency of treatments in suppressing GBMs, roadblocks and challenges. A brief discussion of a few promising delivery methods for targeted drug and gene therapy for cancer was also provided. Increment advancements in this field emphasizes the significance of combining different treatment strategies for improved survival and quality of patients' lives.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/terapia , Sistemas de Liberação de Medicamentos , Glioblastoma/tratamento farmacológico , Glioblastoma/terapia , Humanos , Imunoterapia
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