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1.
Genes Cells ; 29(4): 290-300, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38339971

RESUMO

Lung cancer frequently metastasizes to the bones. An in vivo model is urgently required to identify potential therapeutic targets for the prevention and treatment of lung cancer with bone metastasis. We established a lung adenocarcinoma cell subline (H322L-BO4) that specifically showed metastasis to the leg bones and adrenal glands. This was achieved by repeated isolation of metastatic cells from the leg bones of mice. The cells were intracardially injected into nude mice. Survival was prolonged for mice that received H322L-BO4 cells versus original cells (H322L). H322L-BO4 cells did not exhibit obvious changes in general in vitro properties associated with the metastatic potential (e.g., cell growth, migration, and invasion) compared with H322L cells. However, the phosphorylation of chromosome 9 open reading frame 10/oxidative stress-associated Src activator (C9orf10/Ossa) was increased in H322L-BO4 cells. This result confirmed the increased anchorage independence through C9orf10/Ossa-mediated activation of Src family tyrosine kinase. Reduction of C9orf10/Ossa by shRNA reduced cells' metastasis to the leg bone and prolonged survival in mice. These findings indicate that H322L-BO4 cells can be used to evaluate the effect of candidate therapeutic targets against bone metastatic lung cancer cells. Moreover, C9orf10/Ossa may be a useful target for treatment of lung cancer with bone metastasis.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Ósseas , Neoplasias Pulmonares , Animais , Camundongos , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Linhagem Celular Tumoral , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos Nus , Metástase Neoplásica/genética , Quinases da Família src/uso terapêutico , Humanos
2.
Mol Oncol ; 17(6): 1148-1166, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36688680

RESUMO

Tetraploidy is a hallmark of cancer cells, and tetraploidy-selective cell growth suppression is a potential strategy for targeted cancer therapy. However, how tetraploid cells differ from normal diploids in their sensitivity to anti-proliferative treatments remains largely unknown. In this study, we found that tetraploid cells are significantly more susceptible to inhibitors of a mitotic kinesin (CENP-E) than are diploids. Treatment with a CENP-E inhibitor preferentially diminished the tetraploid cell population in a diploid-tetraploid co-culture at optimum conditions. Live imaging revealed that a tetraploidy-linked increase in unsolvable chromosome misalignment caused substantially longer mitotic delay in tetraploids than in diploids upon moderate CENP-E inhibition. This time gap of mitotic arrest resulted in cohesion fatigue and subsequent cell death, specifically in tetraploids, leading to tetraploidy-selective cell growth suppression. In contrast, the microtubule-stabilizing compound paclitaxel caused tetraploidy-selective suppression through the aggravation of spindle multipolarization. We also found that treatment with a CENP-E inhibitor had superior generality to paclitaxel in its tetraploidy selectivity across a broader spectrum of cell lines. Our results highlight the unique properties of CENP-E inhibitors in tetraploidy-selective suppression and their potential use in the development of tetraploidy-targeting interventions in cancer.


Assuntos
Proteínas Cromossômicas não Histona , Neoplasias , Tetraploidia , Humanos , Linhagem Celular , Microtúbulos , Mitose , Paclitaxel/farmacologia , Proteínas Cromossômicas não Histona/antagonistas & inibidores
3.
Nat Commun ; 13(1): 7262, 2022 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-36433967

RESUMO

N-glycan-mediated activation of the thrombopoietin receptor (MPL) under pathological conditions has been implicated in myeloproliferative neoplasms induced by mutant calreticulin, which forms an endogenous receptor-agonist complex that traffics to the cell surface and constitutively activates the receptor. However, the molecular basis for this mechanism is elusive because oncogenic activation occurs only in the cell-intrinsic complex and is thus cannot be replicated with external agonists. Here, we describe the structure and function of a marine sponge-derived MPL agonist, thrombocorticin (ThC), a homodimerized lectin with calcium-dependent fucose-binding properties. In-depth characterization of lectin-induced activation showed that, similar to oncogenic activation, sugar chain-mediated activation persists due to limited receptor internalization. The strong synergy between ThC and thrombopoietin suggests that ThC catalyzes the formation of receptor dimers on the cell surface. Overall, the existence of sugar-mediated MPL activation, in which the mode of activation is different from the original ligand, suggests that receptor activation is unpredictably diverse in living organisms.


Assuntos
Poríferos , Receptores de Trombopoetina , Animais , Lectinas , Poríferos/metabolismo , Receptores de Trombopoetina/metabolismo , Açúcares , Trombopoetina
4.
Oncogene ; 41(18): 2587-2596, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35338344

RESUMO

Diffuse-type gastric cancer (DGC) is a highly invasive subtype of gastric adenocarcinoma that frequently exhibits scattered peritoneal metastasis. Previous studies have shown that the genes of receptor tyrosine kinases (RTKs), such as fibroblast growth factor receptor 2 (FGFR2) or Met, are amplified in some DGC cell lines, leading to the constitutive activation of corresponding RTKs. In these cell lines, the survival of cancer cells appears to be dependent on the activation of RTKs. To gain novel insights into the downstream signaling pathways of RTKs specific to DGC, phosphotyrosine-containing proteins associated with activated FGFR2 were purified through two sequential rounds of immunoprecipitation from the lysates of two DGC cell lines. As a result, transferrin receptor 1 (TfR1) was identified as the binding partner of FGFR2. Biochemical analysis confirmed that TfR1 protein binds to FGFR2 and is phosphorylated at tyrosine 20 (Tyr20) in an FGFR2 kinase activity-dependent manner. The knockdown of TfR1 and treatment with an inhibitor of FGFR2 caused significant impairment in iron uptake and suppression of cellular proliferation in vitro. Moreover, the suppression of expression levels of TfR1 in the DGC cells significantly reduced their tumorigenicity and potency of peritoneal dissemination. It was indicated that TfR1, when phosphorylated by the binding partner FGFR2 in DGC cells, promotes proliferation and tumorigenicity of these cancer cells. These results suggest that the control of TfR1 function may serve as a therapeutic target in DGC with activated FGFR2.


Assuntos
Neoplasias Gástricas , Linhagem Celular Tumoral , Humanos , Fosforilação , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo , Neoplasias Gástricas/patologia , Tirosina/metabolismo
5.
Cancer Lett ; 526: 335-345, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34775002

RESUMO

Diffuse-type gastric carcinoma (DGC) has a poor prognosis due to its rapid diffusive infiltration and frequent peritoneal dissemination. DGC is associated with massive fibrosis caused by aberrant proliferation of cancer-associated fibroblasts (CAFs). Previously, we reported that direct heterocellular interaction between cancer cells and CAFs is important for the peritoneal dissemination of DGC. In this study, we aimed to identify and target the molecules that mediate such heterocellular interactions. Monoclonal antibodies (mAbs) against intact DGC cells were generated and subjected to high-throughput screening to obtain several mAbs that inhibit the adhesion of DGC cells to CAFs. Immunoprecipitation and mass spectrometry revealed that all mAbs recognized integrin α5 complexed with integrin ß1. Blocking integrin α5 in DGC cells or fibronectin, a ligand of integrin α5ß1, deposited on CAFs abrogated the heterocellular interaction. Administration of mAbs or knockout of integrin α5 in DGC cells suppressed their invasion led by CAFs in vitro and peritoneal dissemination in a mouse xenograft model. Altogether, these findings demonstrate that integrin α5 mediates the heterotypic cancer cell-fibroblast interaction during peritoneal dissemination of DGC and may thus be a therapeutic target.


Assuntos
Fibroblastos/metabolismo , Integrina alfa5/metabolismo , Neoplasias Gástricas/genética , Animais , Feminino , Humanos , Camundongos , Camundongos Nus , Ratos , Transfecção
6.
Cancers (Basel) ; 13(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34503119

RESUMO

Diffuse-type gastric carcinoma (DGC) exhibits aggressive progression associated with rapid infiltrative growth, massive fibrosis, and peritoneal dissemination. Gene amplification of Met and fibroblast growth factor receptor 2 (FGFR2) receptor tyrosine kinases (RTKs) has been observed in DGC. However, the signaling pathways that promote DGC progression downstream of these RTKs remain to be fully elucidated. We previously identified an oncogenic tyrosine phosphatase, SHP2, using phospho-proteomic analysis of DGC cells with Met gene amplification. In this study, we characterized SHP2 in the progression of DGC and assessed the therapeutic potential of targeting SHP2. Although SHP2 was expressed in all gastric carcinoma cell lines examined, its tyrosine phosphorylation preferentially occurred in several DGC cell lines with Met or FGFR2 gene amplification. Met or FGFR inhibitor treatment or knockdown markedly reduced SHP2 tyrosine phosphorylation. Knockdown or pharmacological inhibition of SHP2 selectively suppressed the growth of DGC cells addicted to Met or FGFR2, even when they acquired resistance to Met inhibitors. Moreover, SHP2 knockdown or pharmacological inhibition blocked the migration and invasion of Met-addicted DGC cells in vitro and their peritoneal dissemination in a mouse xenograft model. These results indicate that SHP2 is a critical regulator of the malignant progression of RTK-addicted DGC and may be a therapeutic target.

7.
Oncogenesis ; 10(3): 25, 2021 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33677467

RESUMO

Met gene amplification has been found in a subset of malignant carcinomas, including diffuse-type gastric carcinoma (DGC), which has a poor prognosis owing to rapid infiltrative invasion and frequent peritoneal dissemination. Met is considered a promising therapeutic target for DGC. However, DGC cells with Met gene amplification eventually acquire resistance to Met inhibitors. Therefore, identification of alternate targets that mediate Met signaling and confer malignant phenotypes is critical. In this study, we conducted a phosphoproteomic analysis of DGC cells possessing Met gene amplification and identified Pleckstrin Homology Domain Containing A5 (PLEKHA5) as a protein that is tyrosine-phosphorylated downstream of Met. Knockdown of PLEKHA5 selectively suppressed the growth of DGC cells with Met gene amplification by inducing apoptosis, even though they had acquired resistance to Met inhibitors. Moreover, PLEKHA5 silencing abrogated the malignant phenotypes of Met-addicted DGC cells, including peritoneal dissemination in vivo. Mechanistically, PLEKHA5 knockdown dysregulates glycolytic metabolism, leading to activation of the JNK pathway that promotes apoptosis. These results indicate that PLEKHA5 is a novel downstream effector of amplified Met and is required for the malignant progression of Met-addicted DGC.

8.
Cancer Sci ; 111(7): 2431-2439, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32415892

RESUMO

MYCN gene amplification is consistently associated with poor prognosis in patients with neuroblastoma, a pediatric tumor arising from the sympathetic nervous system. Conventional anticancer drugs, such as alkylating agents and platinum compounds, have been used for the treatment of high-risk patients with MYCN-amplified neuroblastoma, whereas molecule-targeting drugs have not yet been approved. Therefore, the development of a safe and effective therapeutic approach is highly desired. Although thymidylate synthase inhibitors are widely used for colorectal and gastric cancers, their usefulness in neuroblastoma has not been well studied. Here, we investigated the efficacies of approved antifolates, methotrexate, pemetrexed, and raltitrexed (RTX), on MYCN-amplified and nonamplified neuroblastoma cell lines. Cell growth-inhibitory assay revealed that RTX showed a superior inhibitory activity against MYCN-amplified cell lines. We found no significant differences in the protein expression levels of the antifolate transporter or thymidylate synthase, a primary target of RTX, among the cell lines. Because thymidine supplementation could rescue the RTX-induced cell growth suppression, the effect of RTX was mainly due to the reduction in dTTP synthesis. Interestingly, RTX treatments induced single-stranded DNA damage response in MYCN-amplified cells to a greater extent than in the nonamplified cells. We propose that the high DNA replication stress and elevated levels of DNA damage, which are a result of deregulated expression of MYCN target genes, could be the cause of increased sensitivity to RTX.


Assuntos
Dano ao DNA , Amplificação de Genes , Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/genética , Quinazolinas/farmacologia , Tiofenos/farmacologia , Timidilato Sintase/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células , Relação Dose-Resposta a Droga , Humanos , Redes e Vias Metabólicas , Neuroblastoma/metabolismo
9.
Oncol Rep ; 42(4): 1507-1516, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31524271

RESUMO

CUB domain­containing protein 1 (CDCP1) is phosphorylated by Src family kinases (SFK), and is thought to serve an important role in tumor metastasis through downstream signaling subsequent to its interaction with protein kinase C δ. The present study investigated the mechanisms of activation for CDCP1 signaling, and demonstrated that CDCP1 is able to activate SFK via a homophilic complex of the extracellular complement C1r/C1s, urchin embryonic growth factor, bone morphogenetic protein 1 (CUB) 2 domain. Deletion of the extracellular CDCP1 region abolished homophilic complex formation of CDCP1 and the ability to promote cancer cell migration. When the culture medium was supplemented with recombinant CUB2 domain protein fused with maltose binding protein (rMBP­CUB2), CDCP1 homophilic complex formation was effectively inhibited. rMBP­CUB2 also inhibited SFK activation and the migratory capacity of invasive human lung adenocarcinoma A549 cells, and human pancreatic BxPC3 cells. These findings demonstrated a novel function for the extracellular CUB2 domain of CDCP1, promoting cancer cell migration via SFK activation on the plasma membrane. It was also indicated that the region blocking the homophilic binding site may be a potential therapeutic target against CDCP1­dependent tumor invasion.

10.
Artigo em Inglês | MEDLINE | ID: mdl-30978513

RESUMO

We screened 868 marine extracts in search of hematopoietic molecules resulted in findings of several extracts that proliferated Ba/F3-HuMpl cells but not the cells expressed with other hematopoietic cytokine receptors, EPO and G-CSF. Separation of the most potent extract of a Micronesian sponge Corticium sp., guided by the cell proliferation assay using Ba/F3-HuMpl cells resulted in an isolation of thrombocorticin (ThC), a novel 14 kDa protein as an active principal. ThC displayed concentration-dependent proliferation of Ba/F3-HuMpl cells, and had a stronger activity than that of eltrombopag, a small molecule drug used to treat thrombocytopenia. ThC induced phosphorylation of STAT5, suggesting that it activates Jak/STAT pathway as in the case of TPO. These results together indicated that ThC is a specific agonist for c-Mpl, although the size and shape differs largely from TPO. Here we present isolation, characterization and biological activity of ThC.


Assuntos
Poríferos/química , Proteínas/farmacologia , Receptores de Trombopoetina/agonistas , Animais , Linhagem Celular , Camundongos , Proteínas/química , Transdução de Sinais/efeitos dos fármacos
11.
Mar Drugs ; 17(4)2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30965587

RESUMO

A novel protein, soritesidine (SOR) with potent toxicity was isolated from the marine sponge Spongosorites sp. SOR exhibited wide range of toxicities over various organisms and cells including brine shrimp (Artemia salina) larvae, sea hare (Aplysia kurodai) eggs, mice, and cultured mammalian cells. Toxicities of SOR were extraordinary potent. It killed mice at 5 ng/mouse after intracerebroventricular (i.c.v.) injection, and brine shrimp and at 0.34 µg/mL. Cytotoxicity for cultured mammalian cancer cell lines against HeLa and L1210 cells were determined to be 0.062 and 12.11 ng/mL, respectively. The SOR-containing fraction cleaved plasmid DNA in a metal ion dependent manner showing genotoxicity of SOR. Purified SOR exhibited molecular weight of 108.7 kDa in MALDI-TOF MS data and isoelectric point of approximately 4.5. N-terminal amino acid sequence up to the 25th residue was determined by Edman degradation. Internal amino acid sequences for fifteen peptides isolated from the enzyme digest of SOR were also determined. None of those amino acid sequences showed similarity to existing proteins, suggesting that SOR is a new proteinous toxin.


Assuntos
Toxinas Marinhas/toxicidade , Poríferos , Sequência de Aminoácidos , Animais , Aplysia/efeitos dos fármacos , Artemia/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Bioensaio/métodos , Linhagem Celular Tumoral , Humanos , Japão , Larva/efeitos dos fármacos , Masculino , Toxinas Marinhas/administração & dosagem , Toxinas Marinhas/química , Toxinas Marinhas/isolamento & purificação , Camundongos , Peso Molecular , Testes de Mutagenicidade/métodos
12.
Cell Death Discov ; 4: 56, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29760954

RESUMO

Anaplastic lymphoma kinase (ALK) is an oncogenic receptor tyrosine kinase that is activated by gene amplification and mutation in neuroblastomas. ALK inhibitors can delay the progression of ALK-driven cancers, but are of limited use owing to ALK inhibitor resistance. Here, we show that resistance to ALK inhibitor in ALK-driven neuroblastomas can be attenuated by combination treatment with a p53 activator. Either ALK inhibition or p53 activator treatment induced cell cycle arrest, whereas combination treatment induced apoptosis, and prevented tumour relapse both in vitro and in vivo. This shift toward apoptosis, and away from cell-cycle arrest, in the presence of an ALK inhibitor and a p53 activator, is mediated by inhibition of the ALK-AKT-FOXO3a axis leading to a specific upregulation of SOX4. SOX4 cooperates with p53 to upregulate the pro-apoptotic protein PUMA. These data therefore suggest a novel combination therapy strategy for treating ALK-driven neuroblastomas.

13.
Biochem Biophys Res Commun ; 495(2): 1942-1947, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29247652

RESUMO

RhoA is a member of Rho family small GTPases that regulates diverse cellular functions. Recent large-scale sequencing studies have identified recurrent somatic mutations of RHOA in diffuse-type gastric carcinoma (DGC), indicating that RHOA is a driver of DGC. In this study, we investigated the possible abnormalities of RHOA in a panel of gastric carcinoma (GC) cell lines. Pulldown assay and immunoblot analysis showed that the activity and expression of RhoA were detectable in all GC cell lines tested, except for two DGC cell lines, HSC-59 and GSU. RHOA coding region sequencing revealed that aberrant alternative splicing of RHOA occurred in these cell lines. Quantitative real-time PCR analysis showed that the expression of wild-type RHOA was nearly undetectable, whereas splicing variants were almost exclusively expressed in HSC-59 and GSU cell lines. However, the expression levels of RHOA splicing variants were very low and the corresponding proteins were not detected by immunoblotting. Moreover, the splicing isoforms of RhoA protein were neither efficiently expressed nor activated even if ectopically expressed in cells. These results indicate that aberrant alternative splicing of RHOA results in the loss of its activity and expression in DGC cells.


Assuntos
Processamento Alternativo/genética , Regulação Neoplásica da Expressão Gênica/genética , Isoformas de Proteínas/genética , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/genética , Proteína rhoA de Ligação ao GTP/genética , Linhagem Celular Tumoral , Ativação Enzimática/genética , Humanos , Mutação/genética
14.
Biochem Biophys Res Commun ; 495(1): 1292-1299, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29162448

RESUMO

Development of resistance against temozolomide (TMZ) in glioblastoma (GBM) after continuous treatment with TMZ is one of the critical problems in clinical GBM therapy. Intracellular cholesterol regulates cancer cell biology, but whether intracellular cholesterol is involved in TMZ resistance of GBM cells remains unclear. The involvement of intracellular cholesterol in acquired resistance against TMZ in GBM cells was investigated. Intracellular cholesterol levels were measured in human U251 MG cells with acquired TMZ resistance (U251-R cells) and TMZ-sensitive control U251 MG cells (U251-Con cells), and found that the intracellular cholesterol level was significantly lower in U251-R cells than in U251-Con cells. In addition, treatment by intracellular cholesterol remover, methyl-beta cyclodextrin (MßCD), or intracellular cholesterol inducer, soluble cholesterol (Chol), regulated TMZ-induced U251-Con cell death in line with changes in intracellular cholesterol level. Involvement of death receptor 5 (DR5), a death receptor localized in the plasma membrane, was evaluated. TMZ without or with MßCD and/or Chol caused accumulation of DR5 into the plasma membrane lipid raft and formed a complex with caspase-8, an extrinsic caspase cascade inducer, reflected in the induction of cell death. In addition, treatment with caspase-8 inhibitor or knockdown of DR5 dramatically suppressed U251-Con cell death induced by combination treatment with TMZ, MßCD, and Chol. Combined treatment of Chol with TMZ reversed the TMZ resistance of U251-R cells and another GBM cell model with acquired TMZ resistance, whereas clinical antihypercholesterolemia agents at physiological concentrations suppressed TMZ-induced cell death of U251-Con cells. These findings suggest that intracellular cholesterol level affects TMZ treatment of GBM mediated via a DR5-caspase-8 mechanism.


Assuntos
Caspase 8/metabolismo , Colesterol/metabolismo , Dacarbazina/análogos & derivados , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Microdomínios da Membrana/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Antineoplásicos Alquilantes/administração & dosagem , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Dacarbazina/administração & dosagem , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/patologia , Humanos , Líquido Intracelular/metabolismo , Microdomínios da Membrana/efeitos dos fármacos , Temozolomida
15.
Eur J Cell Biol ; 96(7): 685-694, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28797528

RESUMO

Invadopodia are ventral membrane protrusions formed by cancer cells that degrade the extracellular matrix (ECM) during tumor invasion and metastasis. Formation of invadopodia is initiated by the assembly of actin filaments (F-actin) that results from the coordinated activation of several actin regulatory proteins. Actinin-1 and actinin-4 are actin bundling proteins expressed in non-muscle cells and actinin-4 is preferentially associated with malignant phenotypes of carcinoma cells. In this study, we investigated the role of actinin-1 and -4 in invadopodia formation. Expression of both actinin-1 and -4 tended to be higher in invasive and metastatic breast carcinoma cell lines than in non-invasive ones. Immunofluorescence analysis revealed that actinin-1 and -4 colocalized at core actin structures of invadopodia. Time-lapse imaging showed that appearance of both actinins at invadopodia is concomitant with the assembly of F-actin. Knockdown of either actinin-1 or actinin-4 suppressed the formation of invadopodia and degradation of the ECM by carcinoma cells. Interestingly, overexpression of actinin-4, but not actinin-1, significantly promoted the formation of invadopodia and this activity required the actin binding domains and the unique N-terminal motif that exists only in actinin-4. These results demonstrate that both actinin-1 and actinin-4 participate in the assembly of F-actin at invadopodia. Additionally, actinin-4 may have a selective advantage in accelerating invadopodia-mediated invasion of carcinoma cells.


Assuntos
Actinina/genética , Neoplasias da Mama/genética , Podossomos/genética , Actinas/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Cortactina/genética , Matriz Extracelular/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Invasividade Neoplásica/genética , Podossomos/metabolismo , Imagem com Lapso de Tempo
16.
Mar Drugs ; 15(6)2017 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-28574432

RESUMO

Egg lectins occur in a variety of animals ranging from mollusks to vertebrates. A few examples of molluscan egg lectins have been reported, including that of the sea hare Aplysia kurodai; however, their biological functions in the egg remain unclarified. We report the isolation, determination of primary structure, and possible functions of A.kurodai lectin (AKL) from the egg mass of A. kurodai. We obtained AKL as an inseparable mixture of isoproteins with a relative molecular mass of approximately 32 kDa by affinity purification. The hemagglutinating activity of AKL against rabbit erythrocytes was inhibited most potently by galacturonic acid and moderately by xylose. Nucleotide sequencing of corresponding cDNA obtained by rapid amplification of cDNA ends (RACE) allowed us to deduce complete amino acid sequences. The mature polypeptides consisted of 218- or 219-amino acids with three repeated domains. The amino acid sequence had similarities to hypothetical proteins of Aplysia spp., or domain DUF3011 of uncharacterized bacterial proteins. AKL is the first member of the DUF3011 family whose function, carbohydrate recognition, was revealed. Treatment of the egg with galacturonic acid, an AKL sugar inhibitor, resulted in deformation of the veliger larvae, suggesting that AKL is involved in organogenesis in the developmental stage of A. kurodai.


Assuntos
Aplysia/genética , Aplysia/metabolismo , Lebres/genética , Lebres/metabolismo , Ácidos Hexurônicos/metabolismo , Lectinas/genética , Lectinas/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sequência de Bases , DNA Complementar/genética , Eritrócitos/metabolismo , Coelhos
17.
Cancer Sci ; 108(5): 1049-1057, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28256037

RESUMO

CUB domain-containing protein-1 (CDCP1) is a trans-membrane protein predominantly expressed in various cancer cells and involved in tumor progression. CDCP1 is phosphorylated at tyrosine residues in the intracellular domain by Src family kinases and recruits PKCδ to the plasma membrane through tyrosine phosphorylation-dependent association with the C2 domain of PKCδ, which in turn induces a survival signal in an anchorage-independent condition. In this study, we used our cell-free screening system to identify a small compound, glycoconjugated palladium complex (Pd-Oqn), which significantly inhibited the interaction between the C2 domain of PKCδ and phosphorylated CDCP1. Immunoprecipitation assays demonstrated that Pd-Oqn hindered the intercellular interaction of phosphorylated CDCP1 with PKCδ and also suppressed the phosphorylation of PKCδ but not that of ERK or AKT. In addition, Pd-Oqn inhibited the colony formation of gastric adenocarcinoma 44As3 cells in soft agar as well as their invasion. In mouse models, Pd-Oqn markedly reduced the peritoneal dissemination of gastric adenocarcinoma cells and the tumor growth of pancreatic cancer orthotopic xenografts. These results suggest that the novel compound Pd-Oqn reduces tumor metastasis and growth by inhibiting the association between CDCP1 and PKCδ, thus potentially representing a promising candidate among therapeutic reagents targeting protein-protein interaction.


Assuntos
Proliferação de Células/efeitos dos fármacos , Metástase Neoplásica/tratamento farmacológico , Proteínas de Neoplasias/metabolismo , Proteína Quinase C-delta/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Células A549 , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Células HEK293 , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos
18.
Cancer Sci ; 107(3): 369-71, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27027540

RESUMO

The Japan Diabetes Society/Japanese Cancer Association Joint Committee on Diabetes and Cancer published its first report in July 2013 on the epidemiological assessment of the associations of diabetes with cancer risk/prognosis, the common risk factors for diabetes and cancer, and cancer risk associated with diabetes treatment. The Joint Committee continued its work to assess the role of glycemic control in the development of cancer in patients with diabetes. This review shows that high-quality evidence examining the association between glycemic control and cancer risk is lacking.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Neoplasias/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Humanos , Incidência , Japão/epidemiologia , Neoplasias/etiologia , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
19.
Acta Neuropathol ; 131(6): 889-901, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26956871

RESUMO

Germ cell tumors constitute a heterogeneous group that displays a broad spectrum of morphology. They often arise in testes; however, extragonadal occurrence, in particular brain, is not uncommon, and whether they share a common pathogenesis is unknown. We performed whole exome sequencing in 41 pairs of central nervous system germ cell tumors (CNS GCTs) of various histology and their matched normal tissues. We then performed targeted sequencing of 41 selected genes in a total of 124 CNS GCTs, 65 testicular germ cell tumors (tGCTs) and 8 metastatic GCTs to the CNS. The results showed that mutually exclusive mutations of genes involved in the MAPK pathway were most common (48.4 %), typically in KIT (27.4 %), followed by those in the PI3K pathway (12.9 %), particularly in MTOR (6.5 %), among the 124 CNS GCTs. Pure germinomas and non-germinomatous germ cell tumors (NGGCTs), as well as CNS and testicular GCTs, showed similar mutational profiles, suggesting that GCTs share a common molecular pathogenesis. Mutated MTOR identified in CNS GCTs upregulated phosphorylation of the AKT pathway proteins including AKT and 4EBP1 in nutrient-deprived conditions and enhanced soft-agar colony formation; both events were suppressed in a dose-dependent manner by addition of the MTOR inhibitor pp242. Our findings indicate that the dominant genetic drivers of GCTs regardless of the site of origin are activation of the MAPK and/or PI3K pathways by somatic point mutations. Mutated MTOR represents a potential target for novel targeted therapies for refractory GCTs.


Assuntos
Neoplasias do Sistema Nervoso Central/genética , Mutação/genética , Neoplasias Embrionárias de Células Germinativas/genética , Serina-Treonina Quinases TOR/genética , Neoplasias Testiculares/genética , Neoplasias do Sistema Nervoso Central/patologia , Feminino , Humanos , Masculino , Neoplasias Embrionárias de Células Germinativas/terapia , Fosfatidilinositol 3-Quinases/genética , Recidiva , Serina-Treonina Quinases TOR/metabolismo , Neoplasias Testiculares/terapia
20.
Diabetol Int ; 7(1): 12-15, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30603237

RESUMO

The Japan Diabetes Society (JDS)/Japanese Cancer Association (JCA) Joint Committee on Diabetes and Cancer published its first report in July 2013 on the epidemiological assessment of the associations of diabetes with cancer risk/prognosis, the common risk factors for diabetes and cancer, and cancer risk associated with diabetes treatment The JDS/JCA Joint Committee continued its work to assess the role of glycemic control in the development of cancer in patients with diabetes. This review shows that high-quality evidence examining the association between glycemic control and cancer risk is lacking.

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