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1.
J Cell Physiol ; 239(5): e31229, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38426269

RESUMO

RNA-binding proteins (RBPs) play a crucial role in the regulation of posttranscriptional RNA networks, which can undergo dysregulation in many pathological conditions. Human antigen R (HuR) is a highly researched RBP that plays a crucial role as a posttranscriptional regulator. HuR plays a crucial role in the amplification of inflammatory signals by stabilizing the messenger RNA of diverse inflammatory mediators and key molecular players. The noteworthy correlations between HuR and its target molecules, coupled with the remarkable impacts reported on the pathogenesis and advancement of multiple diseases, position HuR as a promising candidate for therapeutic intervention in diverse inflammatory conditions. This review article examines the significance of HuR as a member of the RBP family, its regulatory mechanisms, and its implications in the pathophysiology of inflammation and cardiometabolic illnesses. Our objective is to illuminate potential directions for future research and drug development by conducting a comprehensive analysis of the existing body of research on HuR.


Assuntos
Doenças Cardiovasculares , Proteína Semelhante a ELAV 1 , Inflamação , Humanos , Proteína Semelhante a ELAV 1/metabolismo , Proteína Semelhante a ELAV 1/genética , Inflamação/genética , Inflamação/patologia , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/imunologia , Doenças Cardiovasculares/metabolismo , Animais , Regulação da Expressão Gênica , Doenças Metabólicas/genética , Doenças Metabólicas/imunologia , Doenças Metabólicas/metabolismo , Transdução de Sinais , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
2.
Adv Biol (Weinh) ; 6(7): e2200005, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35398976

RESUMO

The anticancer property of silver-copper metallic nanoparticles (AgCu-NPs) is of greater interest in cancer therapeutics; however, its off-target toxicity limits its therapeutic application. Exosomes emerge as one of the leading idiosyncratic nanocarrier choices for cancer therapeutics due to their size, stability, and phenotypic diversity; however, to encapsulate NPs in extracellular vesicles (EVs) without disrupting their inherited functions is far from the expectations. Here, the loading strategy of AgCu-NP conjugated with wheat germ agglutinin (AgCu-NP-WGA) in exosomes during biogenesis for the targeted delivery of anticancer therapeutics to breast cancer is reported. Based on the intrinsic mechanism of endocytosis of WGA, results show that internalization of WGA or AgCu-NP-WGA bypasses the lysosomal pathway and recycles in EVs. On the contrary, the transport of naked AgCu-NPs to lysosomes; mechanistically, an acidic environment causes oxidation of AgCu-NP. Next, the analysis of EVs harvested by differential centrifugation shows that only AgCu-NPs-WGA (Exo-NP) retain their metallic state. Furthermore, Exo-NP cytotoxicity results manifest that MCF10A-derived Exo-NPs are toxic to its homologous breast cancer cells (MCF-7 and MDA-MB 231) and nontoxic to heterologous cancers NC1-1975 and MCF 10A. In conclusion, this study shows the self-assembly of AgCu-NP in exosomes to target and deliver therapeutics for breast cancer.


Assuntos
Neoplasias da Mama , Exossomos , Nanopartículas Metálicas , Neoplasias da Mama/tratamento farmacológico , Cobre/farmacologia , Exossomos/metabolismo , Feminino , Humanos , Nanopartículas Metálicas/uso terapêutico , Prata/farmacologia , Aglutininas do Germe de Trigo/metabolismo
3.
Sci Rep ; 12(1): 3332, 2022 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-35228650

RESUMO

Vascular and inflammatory mechanisms are implicated in the development of cerebrovascular disease and corneal nerve loss occurs in patients with transient ischemic attack (TIA) and acute ischemic stroke (AIS). We have assessed whether serum markers of inflammation and vascular integrity are associated with the severity of corneal nerve loss in patients with TIA and AIS. Corneal confocal microscopy (CCM) was performed to quantify corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD) and corneal nerve fiber length (CNFL) in 105 patients with TIA (n = 24) or AIS (n = 81) and age matched control subjects (n = 56). Circulating levels of IL-6, MMP-2, MMP-9, E-Selectin, P-Selectin and VEGF were quantified in patients within 48 h of presentation with a TIA or AIS. CNFL (P = 0.000, P = 0.000), CNFD (P = 0.122, P = 0.000) and CNBD (P = 0.002, P = 0.000) were reduced in patients with TIA and AIS compared to controls, respectively with no difference between patients with AIS and TIA. The NIHSS Score (P = 0.000), IL-6 (P = 0.011) and E-Selectin (P = 0.032) were higher in patients with AIS compared to TIA with no difference in MMP-2 (P = 0.636), MMP-9 (P = 0.098), P-Selectin (P = 0.395) and VEGF (P = 0.831). CNFL (r = 0.218, P = 0.026) and CNFD (r = 0.230, P = 0.019) correlated with IL-6 and multiple regression analysis showed a positive association of CNFL and CNFD with IL-6 (P = 0.041, P = 0.043). Patients with TIA and AIS have evidence of corneal nerve loss and elevated IL6 and E-selectin levels. Larger longitudinal studies are required to determine the association between inflammatory and vascular markers and corneal nerve fiber loss in patients with cerebrovascular disease.


Assuntos
Ataque Isquêmico Transitório , AVC Isquêmico , Biomarcadores , Córnea/inervação , Selectina E , Humanos , Inflamação , Interleucina-6 , Ataque Isquêmico Transitório/complicações , Metaloproteinase 2 da Matriz , Metaloproteinase 9 da Matriz , Microscopia Confocal , Fator A de Crescimento do Endotélio Vascular
4.
Front Immunol ; 13: 1097117, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36741391

RESUMO

Immune checkpoint inhibitors (ICIs) including anti-PD-1 and anti-PD-L1 antibodies, have significantly changed the treatment outcomes of NSCLC patients with better overall survival. However, 15-40% of the patients still fail to respond to ICIs therapy. Identification of biomarkers associated with responses are mandated in order to increase the efficacy of such therapy. In this study we evaluated 27 serum-derived exosomal immuno-oncological proteins and 44 cytokines/chemokines before and after ICIs therapy in 17 NSCLC patients to identify surrogate biomarkers for treatment/monitoring patient stratification for maximum therapeutic benefit. We first confirmed the identity of the isolated exosomes to have their specific markers (CD63, CD81, HSP70 and CD91). We have demonstrated that baseline concentration of exosomal-PD-L1 (p<0.0001), exosomal-PD-L2 (p=0.0413) and exosomal-PD-1 (p=0.0131) from NSCLC patients were significantly higher than their soluble-free forms. Furthermore, the exosomal-PD-L1 was present in all the patients (100%), while only 71% of patients expressed tissue PD-L1. This indicates that exosomal-PD-L1 is a more reliable diagnostic biomarker. Interestingly, exosomal-PD-L2 expression was significantly higher (p=0.0193) in tissue PD-L1-negative patients compared to tissue PD-L1-positive patients. We have also shown that immuno-oncological proteins isolated from pre-ICIs treated patients were significantly higher in exosomes compared to their soluble-free counterparts (CD152, p=0.0008; CD80, p=0.0182; IDO, p=0.0443; Arginase, p<0.0001; Nectin-2, p<0.0001; NT5E, p<0.0001; Siglec-7, p<0.0001; Siglec-9, p=0.0335; CD28, p=0.0092; GITR, p<0.0001; MICA, p<0.0001). Finally, the changes in the expression levels of exosomal immuno-oncological proteins/cytokines and their correlation with tumor response to ICIs treatment were assessed. There was a significant downregulation of exosomal PD-L1 (p=0.0156), E-Cadherin (p=0.0312), ULBP1 (p=0.0156), ULBP3 (p=0.0391), MICA (p=0.0391), MICB (p=0.0469), Siglec7 (p=0.0078) and significant upregulation of exosomal PD-1 (p=0.0156) and IFN- γ (p=0.0156) in responding patients. Non-responding patients showed a significant increase in exosomal-PD-L1 (p=0.0078). Furthermore, responding-patients without liver-metastasis showed significant-upregulation of PD-1 (p=0.0070), and downregulation of ULBP1 (p=0.0137) and Siglec-7 (p=0.0037). Non-responding patients had significant-downregulation of ULBP3 (p=0.0317) in patient without brain-metastasis and significant-upregulation/downregulation of PD-L1 and ULBP3 (p=0.0262/0.0286) in patients with pulmonary-metastasis. We demonstrated for the first time that exosomal immuno-oncological proteins/cytokines are potential biomarkers to monitor response to ICIs therapy and can predict the clinical outcomes in NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Inibidores de Checkpoint Imunológico , Neoplasias Pulmonares , Humanos , Biomarcadores , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Citocinas/sangue , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Exossomos , Inibidores de Checkpoint Imunológico/uso terapêutico , Proteínas de Checkpoint Imunológico/sangue
5.
Brain Res ; 1740: 146860, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32353433

RESUMO

Remote ischemic perconditioning (RIPerC) results in collateral enhancement and a reduction in middle cerebral artery occlusion (MCAO) induced ischemia. RIPerC likely activates multiple metabolic protective mechanisms, including effects on matrix metalloproteinases (MMPs) and protein kinases. Here we explore if RIPerC improves neuroprotection and collateral flow by modifying the activities of MMP-9 and AMPK/e-NOS. Age matched adult male Sprague Dawley rats were subjected to MCAO followed one hour later by RIPerC (3 cycles of 15 min ischemia). Animals were euthanized 24 h post-MCAO. Haematoxylin and Eosin (H&E) staining 24 h post-MCAO revealed a significant (p < 0.02) reduction in the infarction volume in RIPerC treated animals (24.9 ± 5.4%) relative to MCAO controls (42.5 ± 4.2, %). TUNEL staining showed a 42.6% reduction in the apoptotic cells with RIPerC treatment (p < 0.01). Immunoblotting in congruence with RT-PCR and Zymography showed that RIPerC significantly reduced MMP-9 expression and activity in RIPerC + MCAO group compared to MCAO group (218.3 ± 19.1% vs. 148.9 ± 12.05% (p < 0.01). Immunoblotting revealed that RIPerC was associated with a significant 2.5-fold increase in activation of p-AMPK compared to the MCAO group (p < 0.01) which was also associated with a significant increase in the e-NOS activity (p < 0.01). RIPerC resulted in reduction of infarction volume, decreased apoptotic cell death and attenuated MMP-9 activity. This together with the increased activity of p-AMPK and increase in p-eNOS may, in part explain the neuroprotection and sustained increase in blood flow observed with RIPerC following acute stroke.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Isquemia Encefálica/metabolismo , Precondicionamento Isquêmico/métodos , Metaloproteinase 9 da Matriz/metabolismo , Neuroproteção/fisiologia , Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Isquemia Encefálica/prevenção & controle , Precondicionamento Isquêmico/tendências , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia
6.
Mol Carcinog ; 59(8): 886-896, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32291806

RESUMO

Inhibiting the disease progression in KRAS-driven cancers after diagnosis has been a difficult task for clinicians to manage due to the lack of effective intervention/preventive therapies. KRAS-driven cancers depend on sustained KRAS signaling. Although developing inhibitors of KRAS signaling has proven difficult in the past, the quest for identifying newer agents has not stopped. Based on studies showing terpenoids as modulators of KRAS-regulated downstream molecular pathways, we asked if this chemical family has an affinity of inhibiting KRAS protein activity. Using crystal structure as a bait in silico, we identified 20 terpenoids for their KRAS protein-binding affinity. We next carried out biological validation of in silico data by employing in situ, in vitro, patient-derived explant ex vivo, and KPC transgenic mouse models. In this report, we provide a comprehensive analysis of a lup-20(29)-en-3b-ol (lupeol) as a KRAS inhibitor. Using nucleotide exchange, isothermal titration calorimetry, differential scanning fluorimetry, and immunoprecipitation assays, we show that lupeol has the potential to reduce the guanosine diphosphate/guanosine triphosphate exchange of KRAS protein including mutant KRASG12V . Lupeol treatment inhibited the KRAS activation in KRAS-activated cell models (NIH-panel, colorectal, lung, and pancreatic intraepithelial neoplasia) and patient tumor explants ex vivo. Lupeol reduced the three-dimensional growth of KRAS-activated cells. The pharmacokinetic analysis showed the bioavailability of lupeol after consumption via oral and intraperitoneal routes in animals. Tested under prevention settings, the lupeol consumption inhibited the development of pancreatic intraepithelial neoplasia in LSL-KRASG12D/Pdx-cre mice (pancreatic ductal adenocarcinoma progression model). These data suggest that the selected members of the triterpene family (such as lupeol) could be exploited as clinical agents for preventing the disease progression in KRAS-driven cancers which however warrants further investigation.


Assuntos
Anti-Inflamatórios/farmacologia , Transformação Celular Neoplásica/efeitos dos fármacos , Modelos Animais de Doenças , Neoplasias Pancreáticas/tratamento farmacológico , Triterpenos Pentacíclicos/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Animais , Apoptose , Proliferação de Células , Transformação Celular Neoplásica/patologia , Progressão da Doença , Feminino , Humanos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Neoplasias Pancreáticas
7.
Transl Oncol ; 12(8): 1056-1071, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31174057

RESUMO

Therapy failure and metastasis-associated mortality are stumbling blocks in the management of PDAC in patients. Failure of therapy is associated to intense hypoxic conditions of tumors. To develop effective therapies, a complete understanding of hypoxia-associated changes in genetic landscape of tumors during disease progression is needed. Because artificially immortalized cell lines do not rightly represent the disease progression, studying genetics of tumors in spontaneous models is warranted. In the current study, we generated a spectrum of spontaneous human (UM-PDC1; UM-PDC2) and murine (HI-PanL, HI-PancI, HI-PanM) models representing localized, invasive, and metastatic PDAC from a patient and transgenic mice (K-rasG12D/Pdxcre/Ink4a/p16-/). These spontaneous models grow vigorously under hypoxia and exhibit activated K-ras signaling, progressive loss of PTEN, and tumorigenicity in vivo. Whereas UM-PDC1 form localized tumors, the UM-PDC2 metastasize to lungs in mice. In an order of progression, these models exhibit genomic instability marked by gross chromosomal rearrangements, centrosome-number variations, Aurora-kinase/H2AX colocalization, loss of primary cilia, and α-tubulin acetylation. The RNA sequencing of hypoxic models followed by qRT-PCR validation and gene-set enrichment identified Intestine-Specific Homeobox factor (ISX)-driven molecular pathway as an indicator PDAC aggressivness. TCGA-PAAD clinical data analysis showed high ISX expression correlation to poor survival of PDAC patients, particularly women. The functional studies showed ISX as a regulator of i) invasiveness and migratory potential and ii) VEGF, MMP2, and NFκB activation in PDAC cells. We suggest that ISX is a potential druggable target and newly developed spontaneous cell models are valuable tools for studying mechanism and testing therapies for PDAC.

8.
Clin Cancer Res ; 24(24): 6421-6432, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30087142

RESUMO

PURPOSE: Metastasis is the major cause of mortality in prostate cancer patients. Factors such as genetic makeup and race play critical role in the outcome of therapies. This study was conducted to investigate the relevance of BMI1 in metastatic prostate cancer disease in Caucasian and African-Americans. EXPERIMENTAL DESIGN: We employed race-specific prostate cancer models, clinical specimens, clinical data mining, gene-microarray, transcription-reporter assay, chromatin-immunoprecipitation (ChIP), IHC, transgenic-(tgfl/fl) zebrafish, and mouse metastasis models. RESULTS: BMI1 expression was observed to be elevated in metastatic tumors (lymph nodes, lungs, bones, liver) of Caucasian and African-American prostate cancer patients. The comparative analysis of stage III/IV tumors showed an increased BMI1 expression in African-Americans than Caucasians. TCGA and NIH/GEO clinical data corroborated to our findings. We show that BMI1 expression (i) positively correlates to metastatic (MYC, VEGF, cyclin D1) and (ii) negative correlates to tumor suppressor (INKF4A/p16, PTEN) levels in tumors. The correlation was prominent in African-American tumors. We show that BMI1 regulates the transcriptional activation of MYC, VEGF, INKF4A/p16, and PTEN. We show the effect of pharmacological inhibition of BMI1 on the metastatic genome and invasiveness of tumor cells. Next, we show the anti-metastatic efficacy of BMI1-inhibitor in transgenic zebrafish and mouse metastasis models. Docetaxel as monotherapy has poor outcome on the growth of metastatic tumors. BMI1 inhibitor as an adjuvant improved the taxane therapy in race-based in vitro and in vivo models. CONCLUSIONS: BMI1, a major driver of metastasis, represents a promising therapeutic target for treating advanced prostate cancer in patients (including those belonging to high-risk group).


Assuntos
Biomarcadores Tumorais , Negro ou Afro-Americano , Complexo Repressor Polycomb 1/genética , Neoplasias da Próstata/genética , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Modelos Animais de Doenças , Docetaxel/farmacologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Terapia de Alvo Molecular , Metástase Neoplásica , Estadiamento de Neoplasias , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , População Branca , Peixe-Zebra
9.
PLoS One ; 12(7): e0180895, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28704451

RESUMO

The X-linked inhibitor of apoptosis (XIAP) is a viable molecular target for anticancer drugs that overcome apoptosis-resistance of malignant cells. XIAP is an inhibitor of apoptosis, mediating through its association with BIR3 domain of caspase 9. Embelin, a quinone derivative isolated from the Embelia ribes plant, has been shown to exhibit chemopreventive, anti-inflammatory, and apoptotic activities via inhibiting XIAP activity. In this study, we found that embelin causes a dose-dependent suppression of proliferation in leukemic cell lines K562 and U937. Embelin mediated inhibition of proliferation correlates with induction of apoptosis. Furthermore, embelin treatment causes loss of mitochondrial membrane potential and release of cytochrome c, resulting in subsequent activation of caspase-3 followed by polyadenosin-5'-diphosphate-ribose polymerase (PARP) cleavage. In addition, embelin treatment of leukemic cells results in a decrease of constitutive phosphorylations/activation level of AKT and downregulation of XIAP. Gene silencing of XIAP and AKT expression showed a link between XIAP expression and activated AKT in leukemic cells. Interestingly, targeting of XIAP and PI3-kinase/AKT signaling augmented inhibition of proliferation and induction of apoptosis in leukemic cells. Altogether these findings raise the possibility that embelin alone or in combination with inhibitors of PI3-kinase/AKT pathway may have therapeutic usage in leukemia and possibly other malignancies with up-regulated XIAP pathway.


Assuntos
Benzoquinonas/farmacologia , Cromonas/farmacologia , Leucemia/metabolismo , Morfolinas/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células K562 , Leucemia/tratamento farmacológico , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
10.
Int J Cancer ; 135(11): 2493-506, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24752651

RESUMO

High-risk populations exhibit early transformation of localized prostate cancer (CaP) disease to metastasis which results in the mortality of such patients. The paucity of knowledge about the molecular mechanism involved in acquiring of metastatic behavior by primary tumor cells and non-availability of reliable phenotype-discriminating biomarkers are stumbling blocks in the management of CaP disease. Here, we determine the role and translational relevance of ROBO1 (an organogenesis-associated gene) in human CaP. Employing CaP-progression models and prostatic tissues of Caucasian and African-American patients, we show that ROBO1 expression is localized to cell-membrane and significantly lost in primary and metastatic tumors. While Caucasians exhibited similar ROBO1 levels in primary and metastatic phenotype, a significant difference was observed between tumor phenotypes in African-Americans. Epigenetic assays identified promoter methylation of ROBO1 specific to African-American metastatic CaP cells. Using African-American CaP models for further studies, we show that ROBO1 negatively regulates motility and invasiveness of primary CaP cells, and its loss causes these cells to acquire invasive trait. To understand the underlying mechanism, we employed ROBO1-expressing/ROBO1-C2C3-mutant constructs, immunoprecipitation, confocal-microscopy and luciferase-reporter techniques. We show that ROBO1 through its interaction with DOCK1 (at SH3-SH2-domain) controls the Rac-activation. However, loss of ROBO1 results in Rac1-activation which in turn causes E-Cadherin/ß-catenin cytoskeleton destabilization and induction of cell migration. We suggest that ROBO1 is a predictive biomarker that has potential to discriminate among CaP types, and could be exploited as a molecular target to inhibit the progression of disease as well as treat metastasis in high-risk populations such as African-Americans.


Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Genes Supressores de Tumor , Proteínas do Tecido Nervoso/metabolismo , Neoplasias da Próstata/etnologia , Neoplasias da Próstata/patologia , Receptores Imunológicos/metabolismo , População Branca/estatística & dados numéricos , Western Blotting , Caderinas/genética , Caderinas/metabolismo , Movimento Celular , Proliferação de Células , Estudos de Coortes , Progressão da Doença , Imunofluorescência , Regulação Neoplásica da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Masculino , Metástase Neoplásica , Estadiamento de Neoplasias , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Fenótipo , Regiões Promotoras Genéticas/genética , Neoplasias da Próstata/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores Imunológicos/antagonistas & inibidores , Receptores Imunológicos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas , Cicatrização , beta Catenina/genética , beta Catenina/metabolismo , Proteínas rac de Ligação ao GTP/genética , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas Roundabout
11.
PLoS One ; 8(10): e78479, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24167630

RESUMO

Blocking the androgen receptor (AR) activity is the main goal of therapies for advanced prostate cancer (PCa). However, relapse with a more aggressive, hormone refractory PCa arises, which harbors restored AR activity. One mechanism of such reactivation occurs through acquisition of AR mutations that enable its activation by various steroidal and non-steroidal structures. Thus, natural and chemical compounds that contribute to inappropriate (androgen-independent) activation of the AR become an area of intensive research. Here, we demonstrate that genistein, a soy phytoestrogen binds to both the wild and the Thr877Ala (T877A) mutant types of AR competitively with androgen, nevertheless, it exerts a pleiotropic effect on PCa cell proliferation and AR activity depending on the mutational status of the AR. Genistein inhibited, in a dose-dependent way, cell proliferation and AR nuclear localization and expression in LAPC-4 cells that have wild AR. However, in LNCaP cells that express the T877A mutant AR, genistein induced a biphasic effect where physiological doses (0.5-5 µmol/L) stimulated cell growth and increased AR expression and transcriptional activity, and higher doses induced inhibitory effects. Similar biphasic results were achieved in PC-3 cells transfected with AR mutants; T877A, W741C and H874Y. These findings suggest that genistein, at physiological concentrations, potentially act as an agonist and activate the mutant AR that can be present in advanced PCa after androgen ablation therapy.


Assuntos
Anticarcinógenos/farmacologia , Genisteína/farmacologia , Mutação de Sentido Incorreto , Proteínas de Neoplasias/biossíntese , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/biossíntese , Substituição de Aminoácidos , Androgênios/química , Androgênios/farmacologia , Anticarcinógenos/química , Linhagem Celular Tumoral , Núcleo Celular/genética , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genisteína/química , Humanos , Masculino , Proteínas de Neoplasias/agonistas , Proteínas de Neoplasias/química , Fitosteróis/química , Fitosteróis/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Glycine max/química
12.
Genes Cancer ; 4(5-6): 224-34, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-24069509

RESUMO

S100A4, a calcium-binding protein, is known for its role in the metastatic spread of tumor cells, a late event of cancer disease. This is the first report showing that S100A4 is not merely a metastatic protein but also an oncoprotein that plays a critical role in the development of tumors. We earlier showed that S100A4 expression progressively increases in prostatic tissues with the advancement of prostate cancer (CaP) in TRAMP, an autochthonous mouse model. To study the functional significance of S100A4 in CaP, we generated a heterozygously deleted S100A4 (TRAMP/S100A4(+/-)) genotype by crossing TRAMP with S100A4(-/-) mice. TRAMP/S100A4(+/-) did not show a lethal phenotype, and transgenes were functional. As compared to age-matched TRAMP littermates, TRAMP/S100A4(+/-) mice exhibited 1) an increased tumor latency period (P < 0.001), 2) a 0% incidence of metastasis, and 3) reduced prostatic weights (P < 0.001). We generated S100A4-positive clones from S100A4-negative CaP cells and tested their potential. S100A4-positive tumors grew at a faster rate than S100A4-negative tumors in vitro and in a xenograft mouse model. The S100A4 protein exhibited growth factor-like properties in multimode (intracellular and extracellular) forms. We observed that 1) the growth-promoting effect of S100A4 is due to its activation of NFκB, 2) S100A4-deficient tumors exhibit reduced NFκB activity, 3) S100A4 regulates NFκB through the RAGE receptor, and 4) S100A4 and RAGE co-localize in prostatic tissues of mice. Keeping in view its growth-promoting role, we suggest that S100A4 qualifies as an excellent candidate to be exploited for therapeutic agents to treat CaP in humans.

13.
PLoS One ; 8(5): e60664, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23671559

RESUMO

For advanced prostate cancer (CaP), the progression of tumors to the state of chemoresistance and paucity of knowledge about the mechanism of chemoresistance are major stumbling blocks in the management of this disease. Here, we provide compelling evidence that BMI1 polycomb group protein and a stem cell factor plays a crucial role in determining the fate of tumors vis-à-vis chemotherapy. We show that progressive increase in the levels of BMI1 occurs during the progression of CaP disease in humans. We show that BMI1-rich tumor cells are non-responsive to chemotherapy whereas BMI1-silenced tumor cells are responsive to therapy. By employing microarray, ChIP, immunoblot and Luciferase reporter assays, we identified a unique mechanism through which BMI1 rescues tumor cells from chemotherapy. We found that BMI1 regulates (i) activity of TCF4 transcriptional factor and (ii) binding of TCF4 to the promoter region of anti-apoptotic BCL2 gene. Notably, an increased TCF4 occupancy on BCL2 gene was observed in prostatic tissues exhibiting high BMI1 levels. Using tumor cells other than CaP, we also showed that regulation of TCF4-mediated BCL2 by BMI1 is universal. It is noteworthy that forced expression of BMI1 was observed to drive normal cells to hyperproliferative mode. We show that targeting BMI1 improves the outcome of docetaxel therapy in animal models bearing chemoresistant prostatic tumors. We suggest that BMI1 could be exploited as a potential molecular target for therapeutics to treat chemoresistant tumors.


Assuntos
Apoptose , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Complexo Repressor Polycomb 1/fisiologia , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Fatores de Transcrição/metabolismo , Animais , Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Senescência Celular , Cisplatino/farmacologia , Docetaxel , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Células HT29 , Humanos , Masculino , Metribolona/farmacologia , Camundongos , Camundongos Nus , Transplante de Neoplasias , Regiões Promotoras Genéticas , Próstata/metabolismo , Neoplasias da Próstata/patologia , Ligação Proteica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transdução de Sinais , Taxoides/farmacologia , Congêneres da Testosterona/farmacologia , Fator de Transcrição 4
14.
PLoS One ; 8(1): e52993, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23308129

RESUMO

BACKGROUND: Lack of reliable predictive biomarkers is a stumbling block in the management of prostate cancer (CaP). Prostate-specific antigen (PSA) widely used in clinics has several caveats as a CaP biomarker. African-American CaP patients have poor prognosis than Caucasians, and notably the serum-PSA does not perform well in this group. Further, some men with low serum-PSA remain unnoticed for CaP until they develop disease. Thus, there is a need to identify a reliable diagnostic and predictive biomarker of CaP. Here, we show that BMI1 stem-cell protein is secretory and could be explored for biomarker use in CaP patients. METHODOLOGY/PRINCIPAL FINDINGS: Semi-quantitative analysis of BMI1 was performed in prostatic tissues of TRAMP (autochthonous transgenic mouse model), human CaP patients, and in cell-based models representing normal and different CaP phenotypes in African-American and Caucasian men, by employing immunohistochemistry, immunoblotting and Slot-blotting. Quantitative analysis of BMI1 and PSA were performed in blood and culture-media of siRNA-transfected and non-transfected cells by employing ELISA. BMI1 protein is (i) secreted by CaP cells, (ii) increased in the apical region of epithelial cells and stromal region in prostatic tumors, and (iii) detected in human blood. BMI1 is detectable in blood of CaP patients in an order of increasing tumor stage, exhibit a positive correlation with serum-PSA and importantly is detectable in patients which exhibit low serum-PSA. The clinical significance of BMI1 as a biomarker could be ascertained from observation that CaP cells secrete this protein in higher levels than cells representative of benign prostatic hyperplasia (BPH). CONCLUSIONS/SIGNIFICANCE: BMI1 could be developed as a dual bio-marker (serum and biopsy) for the diagnosis and prognosis of CaP in Caucasian and African-American men. Though compelling these data warrant further investigation in a cohort of African-American patients.


Assuntos
Complexo Repressor Polycomb 1/sangue , Próstata/patologia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/diagnóstico , Negro ou Afro-Americano , Animais , Biópsia , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Complexo Repressor Polycomb 1/análise , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas/análise , População Branca
15.
Curr Drug Targets ; 13(14): 1907-16, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23140299

RESUMO

Androgen is a key for the activation of Androgen Receptor (AR) in most of the disease conditions, however androgen-independent activation of AR is also found in aggressive type human malignancies. An intense search for the inhibitors of AR is underway to cure AR-dependent diseases. In addition to targeting various components of AR signaling pathway, compounds which directly target AR are under preclinical and clinical investigation. Various In vitro and preclinical animal studies suggest that different natural compounds have potential to act against AR. Some natural compounds have been found to be pharmacologically effective against AR irrespective of varying routs of administration viz; oral, intra-peritoneal and intravenous. This mini-review summarizes the studies conducted with different natural agents in determining their pharmacological utility against AR signaling.


Assuntos
Antagonistas de Receptores de Andrógenos/administração & dosagem , Sistemas de Liberação de Medicamentos/tendências , Nível de Saúde , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Receptores Androgênicos/metabolismo , Antagonistas de Receptores de Andrógenos/metabolismo , Androgênios/metabolismo , Animais , Sistemas de Liberação de Medicamentos/métodos , Humanos , Masculino , Neoplasias Hormônio-Dependentes/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
16.
Biologics ; 6: 267-76, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22956858

RESUMO

The treatment landscape for patients with castration-resistant prostate cancer (CRPC) is undergoing significant changes with the advent of new therapies and multidisciplinary efforts by scientists and clinicians. As activation of multiple molecular pathways in the neoplastic prostate makes it impossible for single-target drugs to be completely effective in treating CRPC, this has led to combination therapy strategy, where several molecules involved in tumor growth and disease progression are targeted by a therapeutic regimen. In the present review, we provide an update on the molecular pathways that play an important role in the pathogenesis of CRPC and discuss the current wave of new treatments to combat this lethal disease.

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