Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Prostate ; 82(10): 1025-1039, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35365850

RESUMEN

BACKGROUND: Prostate cancer is a bone metastatic cancer and is the second leading cause of cancer-related death in men. Prolonged progression-free survival of prostate cancer patients is associated with high regucalcin expression in the tumor tissues. This study investigates the underlying mechanism by which regucalcin prevents bone metastatic activity of prostate cancer cells. METHODS: Human prostate cancer PC-3 or DU-145 wild-type cells or regucalcin-overexpressing PC-3 or DU-145 cells (transfectants) were cultured in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum. RESULTS: Overexpressed regucalcin suppressed the migration and invasion of bone metastatic human prostate cancer cells in vitro, and it reduced the levels of key proteins in metastasis including Ras, Akt, MAPK, RSK-2, mTOR, caveolin-1, and integrin ß1. Invasion of prostate cancer cells was promoted by coculturing with preosteoblastic MC3T3-E1 or preosteoclastic RAW264.7 cells. Coculturing with cancer cells and bone cells repressed the growth of preosteoblastic cells and enhanced osteoclastogenesis of preosteoclastic cells, and these alterations were caused by a conditioned medium from cancer cell culture. Disordered differentiation of bone cells was prevented by regucalcin overexpression. Production of tumor necrosis factor-α (TNF-α) in cancer cells was blocked by overexpressed regucalcin. Of note, the effects of conditioned medium on bone cells were prevented by NF-κB inhibitor. TNF-α may be important as a mediator in the crosstalk between cancer cells and bone cells. CONCLUSION: Overexpression of regucalcin suppressed the migration, invasion, and bone metastatic activity of human prostate cancer cells. This study may provide a new strategy for therapy with the regucalcin gene transfer.


Asunto(s)
Neoplasias Óseas , Proteínas de Unión al Calcio , Péptidos y Proteínas de Señalización Intracelular , Neoplasias de la Próstata , Neoplasias Óseas/secundario , Proteínas de Unión al Calcio/biosíntesis , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/metabolismo , Diferenciación Celular , Medios de Cultivo Condicionados , Humanos , Péptidos y Proteínas de Señalización Intracelular/biosíntesis , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Células PC-3 , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Factor de Necrosis Tumoral alfa/metabolismo
2.
Oncology ; 100(7): 399-412, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35340010

RESUMEN

INTRODUCTION: Regucalcin plays a multifunctional role in the regulation of cellular function including metabolism, signaling process, and transcriptional activity in maintaining cell homeostasis. Downregulated expression or activity of regucalcin contributes to the development of malignancies in various types of human cancer. Survival of cancer patients, including metastatic prostate cancer, is prolonged with high expression of regucalcin in the tumor tissues. METHODS: We elucidate whether extracellular regucalcin conquers the growth, migration, invasion, and adhesion of metastatic human prostate cancer PC-3 and DU-145 cells. RESULTS: Extracellular regucalcin (0.1, 1, and 10 nM) of physiologic levels (1 nM at human serum) inhibited colony formation and growth of PC-3 and DU-145 cells, while it did not have an effect on cell death. Repressive effects of extracellular regucalcin on the proliferation were not exhibited by the presence of inhibitors of the cell cycle, intracellular signaling process, and transcriptional activity, suggesting that the signals of extracellular regucalcin are transmitted to block cell growth. Furthermore, extracellular regucalcin (0.1, 1, or 10 nM) inhibited migration, invasion, and adhesion of PC-3 and DU-145 cells. Mechanistically, extracellular regucalcin (10 nM) decreased the levels of various signaling proteins including Ras, posphatidylinositol-3 kinase, mitogen-activated protein kinase, mechanistic target of rapamycin, RSK-2, caveolin-1, and integrin ß1 in PC-3 cells. DISCUSSION AND CONCLUSION: Thus, extracellular regucalcin may play a suppressive role in growth, migration, invasion, and adhesion, which are involved in the metastatic activity of human prostate cancer cells, via affecting diverse signaling processes. This study may provide a new strategy in preventing metastatic prostate cancer with exogenous regucalcin.


Asunto(s)
Péptidos y Proteínas de Señalización Intracelular , Neoplasias de la Próstata , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/metabolismo , Proteínas de Unión al Calcio/farmacología , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino
3.
Anticancer Drugs ; 32(5): 558-566, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-33595948

RESUMEN

Hepatocellular carcinoma (HCC) is one of the most prevalent malignant diseases and causes a third of cancer-related death. The prognosis and effective treatment of advanced HCC remains poor in spite of the development of novel therapeutic strategies. In the present study, we investigate anticancer effects of the botanical molecule p-hydroxycinnamic acid (HCA) in the HepG2 liver cancer model in vitro. Culturing with HCA (10-1000 nM) suppressed colony formation and growth of HepG2 cells. Mechanistically, culturing with HCA decreased levels of Ras, PI3K, Akt, MAPK, NF-κB p65 and ß-catenin, which are linked to processes of cell signaling and transcription, and increased levels of retinoblastoma and regucalcin, which are suppressors for carcinogenesis. These alterations may lead to the suppression of cell growth. Furthermore, culturing with HCA (10-1000 nM) stimulated cell death due to increased caspase-3 levels. Interestingly, the effects of HCA on the growth and death of HepG2 cells were inhibited by culturing with CH223191, an antagonist of aryl hydrocarbon receptor (AHR), suggesting that the flavonoid effects are, at least partly, mediated by activation of AHR signaling. Notably, HCA blocked stimulatory effects of Bay K 8644, an agonist of L-type calcium channel, on the growth of HepG2 cells. Thus, our study demonstrates that HCA suppresses the growth and stimulates the death of human liver cancer HepG2 cells in vitro. The botanical molecule HCA may therefore be a useful tool in the treatment of HCC, providing a novel strategy for the therapy of human liver cancers.


Asunto(s)
Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ácidos Cumáricos/farmacología , Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/farmacología , Compuestos Azo/farmacología , Células Hep G2 , Humanos , Pirazoles/farmacología , Receptores de Hidrocarburo de Aril/antagonistas & inhibidores , Transducción de Señal
4.
Eur J Inorg Chem ; 2021(20): 1921-1928, 2021 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-34248416

RESUMEN

A series of gold(I) complexes with the general formula [Au(L2)(L')] (L2=4-phenyl-N-(prop-2-yn-1-yl)quinazoline-2-carboxamide, L'=PPh3 (triphenylphosphine), 1; TPA (1,3,5-triaza-7-phosphaadamantane), 2, and Me2-imy (1,3-dimethylimidazol-2-ylidene), 3) were synthesized and fully characterized by spectroscopic methods. The alkynyl ligand L2 belongs to the quinazoline carboxamide class of ligands that are known to bind to the translocator protein (TSPO) at the outer mitochondrial membrane. 1 and 2 exert cytotoxic effects in bladder cancer cells with IC50 values in the low micromolar range. Further mechanistic analysis indicated that the two complexes both act by inducing reactive oxygen species and caspase-mediated apoptosis. The complexes inhibit thioredoxin reductase, an established target of anticancer gold(I) complexes. Docking studies confirmed that after ligand exchange the free ligand L2 can interact with the TSPO binding site.

5.
Proc Natl Acad Sci U S A ; 115(2): E190-E199, 2018 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-29279389

RESUMEN

Directed migration is essential for cell motility in many processes, including development and cancer cell invasion. RSKs (p90 ribosomal S6 kinases) have emerged as central regulators of cell migration; however, the mechanisms mediating RSK-dependent motility remain incompletely understood. We have identified a unique signaling mechanism by which RSK2 promotes cell motility through leukemia-associated RhoGEF (LARG)-dependent Rho GTPase activation. RSK2 directly interacts with LARG and nucleotide-bound Rho isoforms, but not Rac1 or Cdc42. We further show that epidermal growth factor or FBS stimulation induces association of endogenous RSK2 with LARG and LARG with RhoA. In response to these stimuli, RSK2 phosphorylates LARG at Ser1288 and thereby activates RhoA. Phosphorylation of RSK2 at threonine 577 is essential for activation of LARG-RhoA. Moreover, RSK2-mediated motility signaling depends on RhoA and -B, but not RhoC. These results establish a unique RSK2-dependent LARG-RhoA signaling module as a central organizer of directed cell migration and invasion.


Asunto(s)
Movimiento Celular , Factores de Intercambio de Guanina Nucleótido Rho/metabolismo , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Serina/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Línea Celular Tumoral , Activación Enzimática , Células HEK293 , Humanos , Mutación , Fosforilación , Interferencia de ARN , Factores de Intercambio de Guanina Nucleótido Rho/genética , Proteínas Quinasas S6 Ribosómicas 90-kDa/genética , Serina/genética , Transducción de Señal/genética , Treonina/metabolismo , Proteínas de Unión al GTP rho/genética
6.
Gastroenterology ; 156(8): 2297-2312, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30836096

RESUMEN

BACKGROUND & AIMS: Interleukin 6 (IL6) and tumor necrosis factor contribute to the development of colitis-associated cancer (CAC). We investigated these signaling pathways and the involvement of G protein subunit alpha i1 (GNAI1), GNAI2, and GNAI3 in the development of CAC in mice and humans. METHODS: B6;129 wild-type (control) or mice with disruption of Gnai1, Gnai2, and/or Gnai3 or conditional disruption of Gnai2 in CD11c+ or epithelial cells were given dextran sulfate sodium (DSS) to induce colitis followed by azoxymethane (AOM) to induce carcinogenesis; some mice were given an antibody against IL6. Feces were collected from mice, and the compositions of microbiomes were analyzed by polymerase chain reactions. Dendritic cells (DCs) and myeloid-derived suppressor cells (MDSCs) isolated from spleen and colon tissues were analyzed by flow cytometry. We performed immunoprecipitation and immunoblot analyses of colon tumor tissues, MDSCs, and mouse embryonic fibroblasts to study the expression levels of GNAI1, GNAI2, and GNAI3 and the interactions of GNAI1 and GNAI3 with proteins in the IL6 signaling pathway. We analyzed the expression of Gnai2 messenger RNA by CD11c+ cells in the colonic lamina propria by PrimeFlow, expression of IL6 in DCs by flow cytometry, and secretion of cytokines in sera and colon tissues by enzyme-linked immunosorbent assay. We obtained colon tumor and matched nontumor tissues from 83 patients with colorectal cancer having surgery in China and 35 patients with CAC in the United States. Mouse and human colon tissues were analyzed by histology, immunoblot, immunohistochemistry, and/or RNA-sequencing analyses. RESULTS: GNAI1 and GNAI3 (GNAI1;3) double-knockout (DKO) mice developed more severe colitis after administration of DSS and significantly more colonic tumors than control mice after administration of AOM plus DSS. Development of increased tumors in DKO mice was not associated with changes in fecal microbiomes but was associated with activation of nuclear factor (NF) κB and signal transducer and activator of transcription (STAT) 3; increased levels of GNAI2, nitric oxide synthase 2, and IL6; increased numbers of CD4+ DCs and MDSCs; and decreased numbers of CD8+ DCs. IL6 was mainly produced by CD4+/CD11b+, but not CD8+, DCs in DKO mice. Injection of DKO mice with a blocking antibody against IL6 reduced the expansion of MDSCs and the number of tumors that developed after CAC induction. Incubation of MDSCs or mouse embryonic fibroblasts with IL6 induced activation of either NF-κB by a JAK2-TRAF6-TAK1-CHUK/IKKB signaling pathway or STAT3 by JAK2. This activation resulted in expression of GNAI2, IL6 signal transducer (IL6ST, also called GP130) and nitric oxide synthase 2, and expansion of MDSCs; the expression levels of these proteins and expansion of MDSCs were further increased by the absence of GNAI1;3 in cells and mice. Conditional disruption of Gnai2 in CD11c+ cells of DKO mice prevented activation of NF-κB and STAT3 and changes in numbers of DCs and MDSCs. Colon tumor tissues from patients with CAC had reduced levels of GNAI1 and GNAI3 and increased levels of GNAI2 compared with normal tissues. Further analysis of a public human colorectal tumor DNA microarray database (GSE39582) showed that low Gani1 and Gnai3 messenger RNA expression and high Gnai2 messenger RNA expression were significantly associated with decreased relapse-free survival. CONCLUSIONS: GNAI1;3 suppresses DSS-plus-AOM-induced colon tumor development in mice, whereas expression of GNAI2 in CD11c+ cells and IL6 in CD4+/CD11b+ DCs appears to promote these effects. Strategies to induce GNAI1;3, or block GNAI2 and IL6, might be developed for the prevention or therapy of CAC in patients.


Asunto(s)
Transformación Celular Neoplásica/genética , Colitis/patología , Neoplasias del Colon/patología , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/genética , Animales , Biopsia con Aguja , Carcinogénesis , Colitis/genética , Neoplasias del Colon/genética , Modelos Animales de Enfermedad , Regulación hacia Abajo/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Inmunohistoquímica , Interleucina-16/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Distribución Aleatoria , Valores de Referencia , Sensibilidad y Especificidad , Transducción de Señal/genética
7.
Mol Cell Biochem ; 472(1-2): 173-185, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32591915

RESUMEN

Hepatocellular carcinoma is one of the most prevalent malignant diseases and causes a third of cancer-related death. The consequences of altered calcium homeostasis in cancer cells may contribute to tumor progression. Regucalcin plays an inhibitory role in calcium signaling linked to transcription regulation. Regucalcin gene expression is downregulated in the tumor tissues of liver cancer patients, suggesting an involvement as a suppressor in hepatocarcinogenesis. We investigated whether Bay K 8644, an agonist of the L-type Ca2+ channel, promotes the growth of human liver cancer and if the effect of Bay K 8644 is suppressed by overexpressed regucalcin using the HepG2 cell model. The colony formation and growth of HepG2 cells were promoted by culturing with Bay K 8644 (0.1-10 nM). This effect was suppressed by inhibitors of signaling processes linked to cell proliferation, including PD98059 and wortmannin. Death of HepG2 cells was stimulated by Bay K 8644 with higher concentrations (25 and 100 nM). The effects of Bay K 8644 on cell growth and death were abolished by verapamil, an antagonist of calcium channel. Mechanistically, culturing with Bay K 8644 increased levels of mitogen-activated protein kinase (MAPK) and phospho-MAPK. Notably, overexpressed regucalcin suppressed Bay K 8644-promoted growth and death of HepG2 cells. Furthermore, overexpressed regucalcin prevented growth and increased death induced by thapsigargin, which induces the release of intracellular stored calcium. Thus, higher regucalcin expression suppresses calcium signaling linked to the growth of liver cancer cells, providing a novel strategy in treatment of hepatocellular carcinoma with delivery of the regucalcin gene.


Asunto(s)
Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/efectos adversos , Agonistas de los Canales de Calcio/efectos adversos , Canales de Calcio Tipo L/química , Proteínas de Unión al Calcio/metabolismo , Carcinoma Hepatocelular/prevención & control , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Neoplasias Hepáticas/prevención & control , Apoptosis , Proteínas de Unión al Calcio/genética , Carcinoma Hepatocelular/etiología , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Proliferación Celular , Humanos , Técnicas In Vitro , Péptidos y Proteínas de Señalización Intracelular/genética , Neoplasias Hepáticas/etiología , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Células Tumorales Cultivadas
8.
Hum Mol Genet ; 26(8): 1458-1464, 2017 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-28175314

RESUMEN

Peptidyl-tRNA hydrolase 2 (PTRH2) regulates integrin-mediated pro-survival and apoptotic signaling. PTRH2 is critical in muscle development and regulates myogenic differentiation. In humans a biallelic mutation in the PTRH2 gene causes infantile-onset multisystem disease with progressive muscle weakness. We report here that the Ptrh2 knockout mouse model recapitulates the progressive congenital muscle pathology observed in patients. Ptrh2 null mice demonstrate multiple degenerating and regenerating muscle fibers, increased central nuclei, elevated creatine kinase activity and endomysial fibrosis. This progressive muscle pathology resembles the muscular dystrophy phenotype in humans and mice lacking the α7 integrin. We demonstrate that in normal muscle Ptrh2 associates in a complex with the α7ß1 integrin at the sarcolemma and Ptrh2 expression is decreased in α7 integrin null muscle. Furthermore, Ptrh2 expression is altered in skeletal muscle of classical congenital muscular dystrophy mouse models. Ptrh2 levels were up-regulated in dystrophin deficient mdx muscle, which correlates with the elevated levels of the α7ß1 integrin observed in mdx muscle and Duchenne muscular dystrophy patients. Similar to the α7 integrin, Ptrh2 expression was decreased in laminin-α2 dyW null gastrocnemius muscle. Our data establishes a PTRH2 mutation as a novel driver of congenital muscle degeneration and identifies a potential novel target to treat muscle myopathies.


Asunto(s)
Hidrolasas de Éster Carboxílico/genética , Integrinas/genética , Proteínas Mitocondriales/genética , Músculo Esquelético/patología , Distrofia Muscular de Duchenne/genética , Animales , Hidrolasas de Éster Carboxílico/biosíntesis , Distrofina/genética , Distrofina/metabolismo , Regulación del Desarrollo de la Expresión Génica , Humanos , Integrinas/biosíntesis , Ratones , Ratones Endogámicos mdx , Ratones Noqueados , Proteínas Mitocondriales/biosíntesis , Desarrollo de Músculos/genética , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patología , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/patología , Sarcolema/genética , Sarcolema/patología
9.
J Cell Sci ; 128(9): 1707-17, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25770104

RESUMEN

Muscle differentiation requires a complex signaling cascade that leads to the production of multinucleated myofibers. Genes regulating the intrinsic mitochondrial apoptotic pathway also function in controlling cell differentiation. How such signaling pathways are regulated during differentiation is not fully understood. Bit-1 (also known as PTRH2) mutations in humans cause infantile-onset multisystem disease with muscle weakness. We demonstrate here that Bit-1 controls skeletal myogenesis through a caspase-mediated signaling pathway. Bit-1-null mice exhibit a myopathy with hypotrophic myofibers. Bit-1-null myoblasts prematurely express muscle-specific proteins. Similarly, knockdown of Bit-1 expression in C2C12 myoblasts promotes early differentiation, whereas overexpression delays differentiation. In wild-type mice, Bit-1 levels increase during differentiation. Bit-1-null myoblasts exhibited increased levels of caspase 9 and caspase 3 without increased apoptosis. Bit-1 re-expression partially rescued differentiation. In Bit-1-null muscle, Bcl-2 levels are reduced, suggesting that Bcl-2-mediated inhibition of caspase 9 and caspase 3 is decreased. Bcl-2 re-expression rescued Bit-1-mediated early differentiation in Bit-1-null myoblasts and C2C12 cells with knockdown of Bit-1 expression. These results support an unanticipated yet essential role for Bit-1 in controlling myogenesis through regulation of Bcl-2.


Asunto(s)
Hidrolasas de Éster Carboxílico/metabolismo , Diferenciación Celular , Desarrollo de Músculos , Animales , Apoptosis , Hidrolasas de Éster Carboxílico/deficiencia , Caspasa 3/metabolismo , Línea Celular , Técnicas de Silenciamiento del Gen , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Biológicos , Fibras Musculares Esqueléticas/patología , Mioblastos/enzimología , Mioblastos/patología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , ARN Interferente Pequeño/metabolismo , Transfección
11.
J Nat Prod ; 78(3): 543-7, 2015 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-25585025

RESUMEN

Two new polycyclic alkaloids, neopetrocyclamines A and B (1 and 2), along with the known metabolites papuamine (3) and haliclonadiamine (4), were isolated from the Indonesian sponge Neopetrosia cf exigua. Neopetrocyclamine A contains a formamidinium moiety, a rare functional group. While these compounds share the same basic biosynthetic building blocks, the size of the ring system differs in 1 and 2 because of the formamidinium moiety. Biological evaluations of 1-4 revealed that papuamine is cytotoxic against glioblastoma SF-295 cells (GI50 = 0.8 µM).


Asunto(s)
Alcaloides/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Diaminas/aislamiento & purificación , Compuestos Policíclicos/aislamiento & purificación , Poríferos/química , Alcaloides/química , Alcaloides/farmacología , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Diaminas/química , Diaminas/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Indonesia , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Compuestos Policíclicos/química , Compuestos Policíclicos/farmacología
12.
Carcinogenesis ; 35(5): 1084-91, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24464785

RESUMEN

Ras is frequently activated in cutaneous squamous cell carcinoma, a prevalent form of skin cancer. However, the pathways that contribute to Ras-induced transformation have not been entirely elucidated. We have previously demonstrated that in transgenic mice, overexpression of the Ras activator RasGRP1 promotes the formation of spontaneous skin tumors and enhances malignant progression in the multistage carcinogenesis skin model that relies on the oncogenic activation of H-Ras. Utilizing a RasGRP1 knockout mouse model (RasGRP1 KO), we now show that lack of RasGRP1 reduced the susceptibility to skin tumorigenesis. The dependency on RasGRP1 was associated with a diminished response to the phorbol ester tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Specifically, we found impairment of epidermal hyperplasia induced by TPA through keratinocyte proliferation. Using a keratinocyte cell line that carries a ras oncogenic mutation, we also demonstrated that RasGRP1 could further activate Ras in response to TPA. Thus, we propose that RasGRP1 upregulates signaling from Ras and contributes to epidermal tumorigenesis by increasing the total dosage of active Ras.


Asunto(s)
Transformación Celular Neoplásica/genética , Eliminación de Gen , Factores de Intercambio de Guanina Nucleótido/genética , Neoplasias Cutáneas/genética , Piel/metabolismo , Animales , Transformación Celular Neoplásica/metabolismo , Codón , Marcación de Gen , Genes ras , Hiperplasia/tratamiento farmacológico , Hiperplasia/genética , Ratones , Ratones Noqueados , Mutación , Piel/patología , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Acetato de Tetradecanoilforbol/efectos adversos , Activación Transcripcional/efectos de los fármacos
13.
J Biol Chem ; 287(52): 43424-37, 2012 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-23118220

RESUMEN

Modulation of integrin activation is important in many cellular functions including adhesion, migration, and assembly of the extracellular matrix. RSK2 functions downstream of Ras/Raf and promotes tumor cell motility and metastasis. We therefore investigated whether RSK2 affects integrin function. We report that RSK2 mediates Ras/Raf inactivation of integrins. As a result, we find that RSK2 impairs cell adhesion and integrin-mediated matrix assembly and promotes cell motility. Active RSK2 appears to affect integrins by reducing actin stress fibers and disrupting focal adhesions. Moreover, RSK2 co-localizes with the integrin activator talin and is present at integrin cytoplasmic tails. It is thereby in a position to modulate integrin activation and integrin-mediated migration. Activation of RSK2 promotes filamin phosphorylation and binding to integrins. We also find that RSK2 is activated in response to integrin ligation to fibronectin. Thus, RSK2 could participate in a feedback loop controlling integrin function. These results reveal RSK2 as a key regulator of integrin activity and provide a novel mechanism by which it may promote cell migration and cancer metastasis.


Asunto(s)
Movimiento Celular/fisiología , Integrinas/metabolismo , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Animales , Células CHO , Adhesión Celular/fisiología , Proteínas Contráctiles/genética , Proteínas Contráctiles/metabolismo , Cricetinae , Cricetulus , Activación Enzimática/fisiología , Filaminas , Células HeLa , Humanos , Integrinas/genética , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Metástasis de la Neoplasia , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patología , Fosforilación/fisiología , Proteínas Quinasas S6 Ribosómicas 90-kDa/genética , Talina/genética , Talina/metabolismo , Quinasas raf/genética , Quinasas raf/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
14.
Life Sci ; 314: 121328, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36584916

RESUMEN

AIMS: Regucalcin, which plays a multifunctional role in cell regulation, contributes as a suppressor in carcinogenesis. Survival of cancer patients is prolonged with high expression of regucalcin in tumor tissues. Ovarian cancer is the most lethal in gynecologic malignancies. This study elucidates the repressive role of regucalcin on the growth of human ovarian cancer SK-OV-3 cells that are resistant to cytotoxic cancer drugs. MATERIALS AND METHODS: SK-OV-3 wild type-cells and regucalcin-overexpressing cells (transfectants) were cultured in Dulbecco's Modification of Eagle's Medium containing 10 % fetal bovine serum. KEY FINDINGS: Colony formation and proliferation of SK-OV-3 cells were repressed by regucalcin overexpression. The suppressive effects of regucalcin on proliferation were independent of cell death. The proliferation of SK-OV-3 wild-type cells was repressed by various inhibitors, including cell cycle, signaling processes, and transcriptional activity. The effects of all inhibitors were not revealed in transfectants, suggesting the involvement of multiple signaling pathways in regucalcin effects. Of note, the overexpressed regucalcin declined the levels of Ras, Akt, mitogen-activating protein kinase, NF-κB p65, ß-catenin, and STAT3, while it raised the levels of tumor suppressors p53 and Rb, and cell cycle inhibitor p21. Interestingly, the stimulatory effects of epidermal growth factor (EGF) on cell proliferation were blocked in regucalcin-overexpressing cells. Extracellular regucalcin repressed the proliferation independent of the death of SK-OV-3 cells and blocked EGF-enhanced cell proliferation. SIGNIFICANCES: The overexpressed regucalcin may repress cell proliferation by targeting diverse signal pathways, including EGF signaling. This study offers a novel approach to the treatment of ovarian cancer with regucalcin.


Asunto(s)
Antineoplásicos , Neoplasias Ováricas , Humanos , Femenino , Factor de Crecimiento Epidérmico/farmacología , Proliferación Celular , Transducción de Señal , Línea Celular Tumoral , Antineoplásicos/farmacología
15.
J Biol Chem ; 286(16): 14713-23, 2011 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-21383007

RESUMEN

Loss of properly regulated cell death and cell survival pathways can contribute to the development of cancer and cancer metastasis. Cell survival signals are modulated by many different receptors, including integrins. Bit-1 is an effector of anoikis (cell death due to loss of attachment) in suspended cells. The anoikis function of Bit-1 can be counteracted by integrin-mediated cell attachment. Here, we explored integrin regulation of Bit-1 in adherent cells. We show that knockdown of endogenous Bit-1 in adherent cells decreased cell survival and re-expression of Bit-1 abrogated this effect. Furthermore, reduction of Bit-1 promoted both staurosporine and serum-deprivation induced apoptosis. Indeed knockdown of Bit-1 in these cells led to increased apoptosis as determined by caspase-3 activation and positive TUNEL staining. Bit-1 expression protected cells from apoptosis by increasing phospho-IκB levels and subsequently bcl-2 gene transcription. Protection from apoptosis under serum-free conditions correlated with bcl-2 transcription and Bcl-2 protein expression. Finally, Bit-1-mediated regulation of bcl-2 was dependent on focal adhesion kinase, PI3K, and AKT. Thus, we have elucidated an integrin-controlled pathway in which Bit-1 is, in part, responsible for the survival effects of cell-ECM interactions.


Asunto(s)
Hidrolasas de Éster Carboxílico/metabolismo , Regulación de la Expresión Génica , Proteínas Mitocondriales/metabolismo , Animales , Apoptosis , Células CHO , Caspasa 3/metabolismo , Adhesión Celular , Supervivencia Celular , Cricetinae , Cricetulus , Medio de Cultivo Libre de Suero/farmacología , Fibronectinas/química , Proteínas Fluorescentes Verdes/química , Humanos , Integrinas/metabolismo , Ratones , Metástasis de la Neoplasia , Plásmidos/metabolismo , Transfección
16.
Int J Cancer ; 131(7): 1556-68, 2012 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-22213050

RESUMEN

ERK and RSK2 drive proliferation and invasion of many cancers. Phosphoprotein enriched in astrocytes 15 (PEA15) binds ERK and RSK2 and high PEA15 levels can impair ERK- and RSK2-dependent transcription. PEA15 expression also inversely correlates with cell motility and invasiveness. We therefore tested PEA15 effects on neuroblastoma cells in vitro. We further analyzed PEA15 expression in the context of clinical and genetic features of neuroblastoma in tumor samples to determine its correlation with disease progression. Affymetrix microarray analysis was performed using 24 different neuroblastoma cell lines. Cell lines expressing low to intermediate levels of PEA15 were chosen for in vitro functional studies. The cell line results were verified by Affymetrix analysis of three different neuroblastic tumor types (total of 110 samples) PEA15 overexpression inhibited neuroblastoma migration in vitro. We verified that inhibition of motility required PEA15 interaction with its binding partners ERK and RSK2. Additionally, synthetic inhibitors of RSK2 suppressed integrin-dependent migration. PEA15 expression correlates with clinical parameters and a 25% increase in patient survival rate. The highest PEA15 levels were found in low stage, more differentiated and less metastatic neuroblastic tumors, and correlated with lack of MYCN amplification. PEA15 blocks neuroblastoma migration through inhibition of ERK/RSK2 signaling. PEA15 expression levels correlate with favorable clinical features suggesting that PEA15 limits metastatic progression of neuroblastoma. Thus, PEA15 and its partners ERK and RSK2 are potential targets for the development of new therapeutics to impede progression of minimal residual disease in patients with high-risk neuroblastoma.


Asunto(s)
Movimiento Celular/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Neuroblastoma/diagnóstico , Neuroblastoma/genética , Fosfoproteínas/genética , Animales , Proteínas Reguladoras de la Apoptosis , Células COS , Adhesión Celular/genética , Línea Celular Tumoral , Chlorocebus aethiops , Aberraciones Cromosómicas , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Amplificación de Genes , Humanos , Integrinas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteína Proto-Oncogénica N-Myc , Neuroblastoma/mortalidad , Proteínas Nucleares/genética , Proteínas Oncogénicas/genética , Fosfoproteínas/metabolismo , Pronóstico , Unión Proteica , ARN Mensajero/metabolismo , Proteínas Quinasas S6 Ribosómicas 90-kDa/antagonistas & inhibidores , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo
17.
Small GTPases ; 13(1): 196-204, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34304710

RESUMEN

The Ras homologous (Rho) protein family of GTPases (RhoA, RhoB and RhoC) are the members of the Ras superfamily and regulate cellular processes such as cell migration, proliferation, polarization, adhesion, gene transcription and cytoskeletal structure. Rho GTPases function as molecular switches that cycle between GTP-bound (active state) and GDP-bound (inactive state) forms. Leukaemia-associated RhoGEF (LARG) is a guanine nucleotide exchange factor (GEF) that activates RhoA subfamily GTPases by promoting the exchange of GDP for GTP. LARG is selective for RhoA subfamily GTPases and is an essential regulator of cell migration and invasion. Here, we describe the mechanisms by which LARG is regulated to facilitate the understanding of how LARG mediates functions like cell motility and to provide insight for better therapeutic targeting of these functions.


Asunto(s)
Leucemia , Proteína de Unión al GTP rhoA , Humanos , Factores de Intercambio de Guanina Nucleótido Rho/genética , Factores de Intercambio de Guanina Nucleótido Rho/metabolismo , Factores de Intercambio de Guanina Nucleótido ras/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Proteína de Unión al GTP rhoB/metabolismo , Proteínas ras/metabolismo , Guanosina Trifosfato , Proteínas de Unión al GTP rho/metabolismo
18.
Life Sci ; 306: 120795, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35835253

RESUMEN

AIMS: RGPR-p117 was originally discovered as a novel transcription factor, which specifically binds to a nuclear factor I (NFI) consensus motif TTGGC(N)6CC in the promoter region of the regucalcin gene. RGPR-p117 is also called as Lztr2 and SEC16B. The role of RGPR-p117 in cell regulation is poorly understood. This study was undertaken to determine whether the overexpression of RGPR-p117 impacts the proliferation of normal rat kidney proximal tubular epithelial NRK-52E cells in vitro. MAIN METHODS: The NRK-52E wild-type cells and RGPR-p117-overexpressing NRK-52E cells were cultured in DMEM containing fetal bovine serum. KEY FINDINGS: The overexpression of RGPR-p117 repressed colony formation and proliferation of NRK-52E cells. Interestingly, RGPR-p117 overexpression blocked cell proliferation promoted by culturing with Bay K 8644, a calcium-entry agonist, and phorbol 12-myristate 13-acetate, an activator of protein kinase C. The depressive effects of RGPR-p117 overexpression on cell proliferation were not occurred by culturing with various inhibitors of cell cycle and intracellular signaling processes. RGPR-p117 overexpression increased the translocation of RGPR-p117 into the nucleus of NRK-52E cells. Mechanistically, RGPR-p117 overexpression diminished the levels of Ras, PI3 kinase, Akt, mitogen-activated protein kinase, and mTOR, while it raised the levels of p53, Rb, p21, and regucalcin. Furthermore, RGPR-p117 overexpression protected cell death caused by apoptosis-inducing factors, suggesting that the suppressive effects of RGPR-p117 on cell growth are independent of cell death. SIGNIFICANCE: The present study demonstrates that the overexpressed transcription factor RGPR-p117 suppresses cell proliferation via targeting diverse signaling processes, suggesting a role of RGPR-p117 in cell regulation.


Asunto(s)
Proteínas de Unión al Calcio , Proteínas de Unión al ADN/metabolismo , Animales , Proteínas de Unión al Calcio/metabolismo , Proliferación Celular , Proteínas de Unión al ADN/genética , Células Epiteliales/metabolismo , Riñón/metabolismo , Factores de Transcripción NFI/genética , Regiones Promotoras Genéticas , Ratas , Transducción de Señal
19.
Front Cell Dev Biol ; 10: 1015665, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36684450

RESUMEN

The 90 kDa ribosomal S6 kinases (RSKs) are serine threonine kinases comprising four isoforms. The isoforms can have overlapping functions in regulation of migration, invasion, proliferation, survival, and transcription in various cancer types. However, isoform specific differences in RSK1 versus RSK2 functions in gene regulation are not yet defined. Here, we delineate ribosomal S6 kinases isoform-specific transcriptional gene regulation by comparing transcription programs in RSK1 and RSK2 knockout cells using microarray analysis. Microarray analysis revealed significantly different mRNA expression patterns between RSK1 knockout and RSK2 knockout cell lines. Importantly some of these functions have not been previously recognized. Our analysis revealed RSK1 has specific roles in cell adhesion, cell cycle regulation and DNA replication and repair pathways, while RSK2 has specific roles in the immune response and interferon signaling pathways. We further validated that the identified gene sets significantly correlated with mRNA datasets from cancer patients. We examined the functional significance of the identified transcriptional programs using cell assays. In alignment with the microarray analysis, we found that RSK1 modulates the mRNA and protein expression of Fibronectin1, affecting cell adhesion and CDK2, affecting S-phase arrest in the cell cycle, and impairing DNA replication and repair. Under similar conditions, RSK2 showed increased ISG15 transcriptional expression, affecting the immune response pathway and cytokine expression. Collectively, our findings revealed the occurrence of RSK1 and RSK2 specific transcriptional regulation, defining separate functions of these closely related isoforms.

20.
FASEB J ; 24(8): 2818-28, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20354143

RESUMEN

PEA-15 is a death effector domain-containing phosphoprotein that binds ERK and restricts it to the cytoplasm. PEA-15 also binds to FADD and thereby blocks apoptosis induced by death receptors. Abnormal expression of PEA-15 is associated with type II diabetes and some cancers; however, its physiological function remains unclear. To determine the function of PEA-15 in vivo, we used C57BL/6 mice in which the PEA-15 coding region was deleted. We thereby found that PEA-15 regulates T-cell proliferation. PEA-15-null mice did not have altered thymic or splenic lymphocyte cellularity or differentiation. However, PEA-15 deficient T cells had increased CD3/CD28-induced nuclear translocation of ERK and increased activation of IL-2 transcription and secretion in comparison to control wild-type littermates. Indeed, activation of the T-cell receptor in wild-type mice caused PEA-15 release of ERK. In contrast, overexpression of PEA-15 in Jurkat T cells blocked nuclear translocation of ERK and IL-2 transcription. Finally, PEA-15-null T cells showed increased IL-2 dependent proliferation on stimulation. No differences in T cell susceptibility to apoptosis were found. Thus, PEA-15 is a novel player in T-cell homeostasis. As such this work may have far reaching implications in understanding how the immune response is controlled.


Asunto(s)
Fosfoproteínas/fisiología , Receptores de Antígenos de Linfocitos T/fisiología , Transducción de Señal , Transporte Activo de Núcleo Celular , Animales , Proteínas Reguladoras de la Apoptosis , Proliferación Celular , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Interleucina-2/genética , Células Jurkat , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosfoproteínas/deficiencia , Fosfoproteínas/inmunología , Linfocitos T/citología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA