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1.
Mol Pharm ; 21(7): 3471-3484, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38872243

RESUMO

Oligonucleotides are short nucleic acids that serve as one of the most promising classes of drug modality. However, attempts to establish a physicochemical evaluation platform of oligonucleotides for acquiring a comprehensive view of their properties have been limited. As the chemical stability and the efficacy as well as the solution properties at a high concentration should be related to their higher-order structure and intra-/intermolecular interactions, their detailed understanding enables effective formulation development. Here, the higher-order structure and the thermodynamic stability of the thrombin-binding aptamer (TBA) and four modified TBAs, which have similar sequences but were expected to have different higher-order structures, were evaluated using ultraviolet spectroscopy (UV), circular dichroism (CD), differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR). Then, the relationship between the higher-order structure and the solution properties including solubility, viscosity, and stability was investigated. The impact of the higher-order structure on the antithrombin activity was also confirmed. The higher-order structure and intra-/intermolecular interactions of the oligonucleotides were affected by types of buffers because of different potassium concentrations, which are crucial for the formation of the G-quadruplex structure. Consequently, solution properties, such as solubility and viscosity, chemical stability, and antithrombin activity, were also influenced. Each instrumental analysis had a complemental role in investigating the higher-order structure of TBA and modified TBAs. The utility of each physicochemical characterization method during the preclinical developmental stages is also discussed.


Assuntos
Aptâmeros de Nucleotídeos , Dicroísmo Circular , Oligonucleotídeos , Aptâmeros de Nucleotídeos/química , Dicroísmo Circular/métodos , Oligonucleotídeos/química , Varredura Diferencial de Calorimetria/métodos , Viscosidade , Espectroscopia de Ressonância Magnética/métodos , Solubilidade , Termodinâmica , Quadruplex G , Estabilidade de Medicamentos , Humanos
2.
Pancreas ; 42(6): 1027-33, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23851436

RESUMO

OBJECTIVES: Pancreatic cancer is one of the most lethal malignancies; its poor prognosis is strongly associated with invasion and metastasis. Expression of S100A4 has been reported to correlate with poor prognosis in various cancers. We have investigated the role of S100A4 in pancreatic cancer tumorigenesis and its clinicopathologic significance. METHODS: Protein expression of S100A4 was examined by Western blot in pancreatic cancer cell lines and a human pancreatic ductal epithelium cell line, HPDE-6. Then the expressions of S100A4, TP53, and CD133 were examined immunohistochemically in resected specimens from 83 patients with pancreatic cancer to clarify their clinicopathologic significance. Survival analyses were performed using the Kaplan-Meier method and the Mantel-Cox method. RESULTS: Forty-eight (58%) of 83 patients with pancreatic cancer positively expressed S100A4, and 50 (60%) and 29 (36%) patients positively expressed TP53 and CD133, respectively. S100A4 expression was significantly correlated with perineural invasion (P = 0.029) and invasion pattern (P = 0.001). Neither TP53 nor CD133 expression showed significant correlations with any other parameters. CONCLUSIONS: Our present results suggest that S100A4 plays an important role in the invasiveness, particularly with perineural invasion and invasion pattern, of pancreatic cancer. Development of new strategies targeting S100A4 or its downstream effectors is warranted.


Assuntos
Adenocarcinoma/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas S100/biossíntese , Antígeno AC133 , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/metabolismo , Western Blotting , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Glicoproteínas/metabolismo , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias Pancreáticas/patologia , Peptídeos/metabolismo , Prognóstico , Proteína A4 de Ligação a Cálcio da Família S100 , Análise Serial de Tecidos , Proteína Supressora de Tumor p53/metabolismo
3.
Biochem Biophys Res Commun ; 390(3): 475-80, 2009 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-19799859

RESUMO

S100A4 protein belongs to the S100 subfamily, which has grown to be one of the large subfamilies of the EF-hand Ca(2+)-binding proteins, and overexpression of S100A4 is suggested to associate with cell proliferation, invasion, and metastasis. We observed frequent overexpression of S100A4 in pancreatic cancer cell lines and further analyzed RNAi-mediated knockdown to address the possibility of its use as a therapeutic target for pancreatic cancer. The specific knockdown of S100A4 strongly suppressed cell growth, induced G2 arrest and eventual apoptosis, and decreased cell migration. Furthermore, microarray analyses revealed that knockdown of S100A4 induced expression of the tumor suppressor genes PRDM2 and VASH1. Our present results suggest the possibility that the inhibition of S100A4 can be utilized in antitumor applications for patients with pancreatic cancer.


Assuntos
Apoptose , Movimento Celular , Proliferação de Células , Neoplasias Pancreáticas/patologia , Proteínas S100/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Histona-Lisina N-Metiltransferase , Humanos , Invasividade Neoplásica , Proteínas Nucleares/genética , Neoplasias Pancreáticas/genética , Interferência de RNA , Proteína A4 de Ligação a Cálcio da Família S100 , Proteínas S100/genética , Fatores de Transcrição/genética
4.
Diabetes Care ; 31(10): 1949-54, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18591401

RESUMO

OBJECTIVE: We assessed the effects of a 2-day in-hospital diabetes educational program in preventing or delaying progression of impaired glucose tolerance (IGT) to type 2 diabetes, including analysis of changes in serum lipids, body weight, and blood pressure after the program. RESEARCH DESIGN AND METHODS: A total of 426 subjects (51 +/- 9 years, BMI 24.6 +/- 3.9 kg/m(2)) with newly diagnosed IGT were randomly assigned to three groups, 143 as the short-term hospitalization with diabetes education and support (STH) group, 141 as the nonhospitalization but diabetes education and support (DES) group, and 142 as the neither hospitalization nor education (control) group. RESULTS: The average follow-up was 3.1 years. The incidence of diabetes was 8.0, 10.7, and 13.2 cases per 100 person-years for STH, DES, and control groups, respectively. The incidence of diabetes was 42% lower (95% CI 33-51%) in the STH group and 27% lower (15-37%) in the DES group than in the control group. The incidence of diabetes was 21% lower (10-31%) in the STH group than in the DES group. CONCLUSIONS: The 2-day in-hospital program with diabetes education and support every 3 months was more effective in preventing or delaying the progression from IGT to diabetes than only diabetes education and support every 3 months.


Assuntos
Diabetes Mellitus Tipo 2/prevenção & controle , Intolerância à Glucose/complicações , Intolerância à Glucose/reabilitação , Pacientes Internados , Educação de Pacientes como Assunto , Adulto , Glicemia/análise , Pressão Sanguínea , Peso Corporal , Diabetes Mellitus Tipo 2/epidemiologia , Progressão da Doença , Feminino , Intolerância à Glucose/sangue , Teste de Tolerância a Glucose , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade
5.
Amyloid ; 15(2): 137-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18484340

RESUMO

A 42-year-old male patient with primary AL amyloidosis experienced spontaneous hepatic rupture, producing diffuse widespread intrahepatic hemorrhage. Transcatheter hepatic artery embolization saved his life. Hepatic rupture infrequently develops in patients with systemic amyloidosis, but survival after this complication is rare because surgical treatments seldom succeed. Non-invasive emergent transcatheter embolization should be considered for hepatic rupture caused by massive deposits of amyloid.


Assuntos
Amiloidose/complicações , Embolização Terapêutica , Hepatopatias/complicações , Hepatopatias/terapia , Adulto , Amiloidose/patologia , Hemorragia/complicações , Hemorragia/terapia , Artéria Hepática , Humanos , Hepatopatias/patologia , Masculino , Ruptura Espontânea/complicações , Ruptura Espontânea/terapia
6.
J Gastroenterol Hepatol ; 23(2): 303-9, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17725600

RESUMO

BACKGROUND AND AIM: Mucosal injury caused by gastroesophageal reflux may result in changes in esophageal mucosal blood flow. Little is known about esophageal mucosal blood flow in patients with gastroesophageal reflux disease (GERD). Here we examined esophageal mucosal blood flow and the effects of treatment in patients with GERD. METHODS: The subjects included 41 cases (21 males and 20 females, mean age 64.2 years) in whom endoscopy was warranted in patients complaining of heartburn and/or regurgitation. We also studied six normal control subjects. Patients underwent endoscopy, laser Doppler flow meter measurements, and endoscopic ultrasonography before and after treatment. RESULTS: Esophageal mucosal/submucosal blood flow was increased in patients with GERD compared with the control patients. The thickness of the whole esophageal wall and that of the mucosal and submucosal layers of the esophagus correlated significantly with esophageal mucosal/submucosal blood flow. The increased esophageal mucosal/submucosal blood flow significantly decreased after 4 weeks' treatment with lansoprazole, a proton pump inhibitor. CONCLUSION: Our results indicated that the pathophysiology or underlying mechanisms of GERD includes increased esophageal mucosal/submucosal blood flow, which correlates with the thickness of the esophageal wall, but is reversible and responds to treatment with lansoprazole. This suggests that proton pump inhibitors can effectively treat GERD and promote histological normalization of the mucosa and submucosa in the lower esophagus.


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/uso terapêutico , Esôfago/irrigação sanguínea , Refluxo Gastroesofágico/tratamento farmacológico , Refluxo Gastroesofágico/fisiopatologia , Mucosa/irrigação sanguínea , Inibidores da Bomba de Prótons/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Endoscopia Gastrointestinal , Esôfago/efeitos dos fármacos , Esôfago/patologia , Famotidina/uso terapêutico , Feminino , Refluxo Gastroesofágico/diagnóstico , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Humanos , Lansoprazol , Fluxometria por Laser-Doppler , Masculino , Pessoa de Meia-Idade , Mucosa/efeitos dos fármacos , Mucosa/patologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Inquéritos e Questionários , Ultrassonografia
7.
Endocr J ; 54(5): 685-93, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17785920

RESUMO

Since accumulation and interaction of immune cells including T cells and monocytes/macrophages are involved in the processes of atherosclerosis, atherosclerosis is currently understood as an inflammatory disorder. Entrapment of extracellular matrices components such as hyaluronan by monocytes and macrophages, as well as uptake of oxidized low-density lipoprotein (ox-LDL) by these cells, plays a central role in foam cell formation and the pathogenesis of atherosclerosis. We investigated the role of CD44, the principal receptor for hyaluronic acid, and ox-LDL in scavenger receptor expression on resting monocytes prepared by counterflow centrifugal elutriation from the endothelium. Our results showed that the low-molecular weight (6.9 kDa) form of hyaluronan increased the expression of CD36 scavenger receptor; the incorporation of (125) I-labeled ox-LDL, and the transendothelial migration of monocytes, which were mediated at least in part via tyrosine kinase and the PKC pathway. Our results imply that low molecular weight hyaluronan produced in large amounts in atherosclerotic lesions induces differentiation of circulating monocytes to macrophages/foam cells and enhances the progression of atherosclerosis via the PKC pathway. Furthermore, low molecular weight hyaluronan also amplifies the migration of monocytes into inflamed atherosclerotic plaques. Thus, we propose that engagement of CD44 with low molecular weight hyaluronan is centrally involved in the inflammatory pathogenesis of athelosclerotic plaques through migration of monocytes and foamed macrophage differentiation.


Assuntos
Ácido Hialurônico/farmacologia , Lipoproteínas LDL/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Idoso , Antígenos CD36/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/patologia , Humanos , Ácido Hialurônico/química , Masculino , Peso Molecular , Monócitos/fisiologia
8.
Endocr J ; 53(6): 761-6, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16966827

RESUMO

Accumulation of hyaluronan (HA) around smooth muscle cells in lesions of atherosclerosis in diabetic patients suggests that this protein plays an important role in diabetic angiopathy. The aim of this study was to determine the correlation between serum HA concentrations and diabetic angiopathy. Diabetic patients treated with or without an oral hypoglycemic agent and/or insulin for at least 1 year were recruited (n = 95). We also included 20 non-diabetic control subjects. We measured serum levels of HA, body mass index (BMI), fasting plasma glucose (FPG), HbA1c, total cholesterol, triglyceride, glycated albumin (GA), high sensitivity CRP (hs-CRP), monocyte chemoattractant protein (MCP)-1 and evaluated diabetes mellitus history, drug use and presence of related complications. Serum HA levels were significantly (P<0.05) higher in diabetic patients (83.6 +/- 5.6 ng/ml, mean +/- SEM) than in normal subjects (41.7 +/- 12 ng/ml). In diabetic patients, serum HA concentration significantly correlated with FPG, HbA1c, GA, triglyceride and also significantly correlated with BMI, hs-CRP and MCP-1 and tended to be higher in diabetic patients with complications than in those without such complications. Our data suggest that serum HA level correlates with poor blood glucose control and diabetic angiopathy and that it could be used as a marker of diabetic angiopathy.


Assuntos
Angiopatias Diabéticas/sangue , Ácido Hialurônico/sangue , Glicemia/análise , Índice de Massa Corporal , Proteína C-Reativa/análise , Quimiocina CCL2/sangue , Diabetes Mellitus Tipo 2/sangue , Hemoglobinas Glicadas , Produtos Finais de Glicação Avançada , Hemoglobinas/análise , Humanos , Albumina Sérica/análise , Triglicerídeos/sangue , Albumina Sérica Glicada
9.
Biochem Biophys Res Commun ; 344(3): 780-5, 2006 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-16631114

RESUMO

Increased monocyte recruitment into subendothelial space in atherosclerotic lesions is one of the hallmarks of diabetic angiopathy. The aim of this study was to determine the state of peripheral blood monocytes in diabetes associated with atherosclerosis. Diabetic patients treated with/without an oral hypoglycemic agent and/or insulin for at least 1 year were recruited (n=106). We also included 24 non-diabetic control subjects. We measured serum levels of monocyte chemoattractant protein (MCP)-1, fasting plasma glucose (FPG), HbA1c, total cholesterol, triglyceride, body mass index (BMI), high sensitivity CRP (hs-CRP) and evaluated CCR2, CD36, CD68 expression on the surface of monocytes. Serum MCP-1 levels were significantly (p<0.05) higher in diabetic patients than in normal subjects. In diabetic patients, serum MCP-1 levels correlated significantly with FPG, HbA1c, triglyceride, BMI, and hs-CRP. The expression levels of CCR2, CD36, and CD68 on monocytes were significantly increased in diabetic patients and were more upregulated by MCP-1 stimulation. Our data suggest that elevated serum MCP-1 levels and increased monocyte CCR2, CD36, CD68 expression correlate with poor blood glucose control and potentially contribute to increased recruitment of monocytes to the vessel wall in diabetes mellitus.


Assuntos
Quimiocina CCL2/imunologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Lipoproteínas LDL/metabolismo , Monócitos/metabolismo , Receptores de Quimiocinas/metabolismo , Células Cultivadas , Regulação da Expressão Gênica , Humanos , Receptores CCR2
11.
Biochem Biophys Res Commun ; 339(3): 846-51, 2006 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-16325770

RESUMO

Functional role of CD44, a principal receptor of hyaluronan, and glycated albumin for differentiation of resting human monocytes isolated by counterflow centrifugal elutriation was investigated. Flow cytometric analysis revealed that amadori-modified glycated albumin induced expression of CD44 as well as macrophage scavenger receptors (MSRs) such as CD36 and CD68 on resting monocytes. Crosslinking of CD44 on monocytes also induced MSR expression. Furthermore, CD44 crosslinking and/or glycated albumin enhanced the uptake of oxidized-low density lipoprotein in monocytes and foam cell formation. Taken together, engagement of CD44 (e.g., hyaluronan) and glycated albumin induced the differentiation of resting monocytes into foam macrophages through the induction of MSRs, implying that CD44 could be involved in atherosclerotic lesions of those such as diabetic patients.


Assuntos
Regulação da Expressão Gênica/fisiologia , Receptores de Hialuronatos/metabolismo , Lipoproteínas LDL/farmacocinética , Monócitos/metabolismo , Receptores Depuradores/metabolismo , Albumina Sérica/administração & dosagem , Células Cultivadas , Reagentes de Ligações Cruzadas , Regulação da Expressão Gênica/efeitos dos fármacos , Produtos Finais de Glicação Avançada , Humanos , Albumina Sérica Glicada
12.
J Gastroenterol Hepatol ; 20(9): 1365-70, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16105122

RESUMO

OBJECTIVE: Majority of studies on gastroesophageal reflux disease (GERD) that include patients with or without erosive disease have documented the efficacy of proton pump inhibitors (PPIs) as well as their superiority to H(2)-receptor antagonist (H(2)-RA). The purpose of this study was to clarify the difference in quality of GERD treatment with PPIs and H(2)-RA in step-down protocol using lansoprazole. METHODS: Forty-three patients with reflux esophagitis were randomly divided into three groups and assessed by severity score; group 1 received 30 mg lansoprazole initially and maintenance therapy with a standard dose H(2)-RA; group 2 received 30 mg of lansoprazole initially and maintenance therapy of 15 mg lansoprazole; and group 3 received 15 mg of lansoprazole once daily for 16 weeks. If the patients experienced symptomatic recurrence while on H(2)-RA, they were switched to PPI maintenance. RESULTS: Heartburn, regurgitation and dysphagia were hardly found in any group at 8 weeks after 15 mg or 30 mg lansoprazole treatment. After 8 weeks, however, heartburn and regurgitation recurred at 50% and 78.6%, respectively, in the stepped down to famotidine group, and quality of life (QOL) was significantly impaired. Endoscopic ultrasonography (EUS) analysis showed reduction of the submucosal layer without any change in the mucosal surface in the stepped down to famotidine group. CONCLUSIONS: Step-down lansoprazole therapy is considered very effective in terms of rapid effect, long-term effect and high quality GERD treatment.


Assuntos
Inibidores Enzimáticos/uso terapêutico , Esofagite Péptica/tratamento farmacológico , Refluxo Gastroesofágico/tratamento farmacológico , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Omeprazol/análogos & derivados , 2-Piridinilmetilsulfinilbenzimidazóis , Idoso , Transtornos de Deglutição/tratamento farmacológico , Endossonografia , Esofagite Péptica/diagnóstico por imagem , Esofagite Péptica/etiologia , Famotidina/uso terapêutico , Feminino , Refluxo Gastroesofágico/complicações , Refluxo Gastroesofágico/diagnóstico por imagem , Azia/tratamento farmacológico , Humanos , Lansoprazol , Masculino , Pessoa de Meia-Idade , Omeprazol/uso terapêutico , Inibidores da Bomba de Prótons , Qualidade de Vida , Recidiva , Resultado do Tratamento
13.
J Bone Miner Res ; 20(6): 1002-10, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15883641

RESUMO

UNLABELLED: One week of tail suspension significantly decreased the expression of PECAM-1 in mouse tibial bone marrow cells but not those of a number of other vascular factors. Anti-PECAM-1 antibody suppressed both ALP+ CFU-f formation and ALP production under co-culture of the osteoblastic cell line and the PECAM-1+ endothelial cell line. This study suggests that the reduced ALP activity after skeletal unloading is related to downregulation of PECAM-1 expression in bone marrow cells in mice. INTRODUCTION: Vascular factors play a role in bone development and regeneration. We tested the hypothesis that skeletal unloading reduces osteogenic potential by inhibiting the molecules related to angiogenesis and/or vasculogenesis in bone marrow cells. MATERIALS AND METHODS: Eight-week-old male mice were assigned to three groups after acclimatization for 1 week: ground control (GC), tail suspension (TS), and reloading after 7-day TS (RL). Bilateral tibial and humeral samples were used for analyses. MC3T3-E1, a mouse osteoblastic cell line, and EOMA and ISOS-1, mouse endothelial cell lines, were also used. RESULTS: Flow cytometric analysis revealed that 7-day TS significantly decreased the expression of platelet endothelial cell adhesion molecule-1 (PECAM-1, CD31) in tibial bone marrow cells, but not those of angiopoietin-1, angiopoietin-2, Flk-1 (vascular endothelial growth factor receptor-2), and vascular endothelial cadherin. The expression of PECAM-1 in tibial marrow cells was reduced at day 3 of TS to 80% and still showed significantly low levels at day 7 of TS to 72% of that at the respective days of GC. This decreased expression of PECAM-1 after 7-day TS showed the GC level at 5-day reloading after 7-day TS. However, the expression of PECAM-1 in humeral marrow cells (internal bone marrow control) after TS and RL remained unchanged and equivalent to that of GC. The expression level of PECAM-1 mRNA was significantly lower at day 7 of TS to 62% of that in GC. Double labeling analyses revealed that PECAM-1+ cells mostly consisted of endothelial cells and partially of granulocytes. In bone marrow cell cultures, the formation of alkaline phosphatase (ALP)+ colony forming units-fibroblastic was significantly reduced in the presence of anti-PECAM-1 antibody in the medium compared with the presence of immunoglobulin G (0.025 times as much as ALP production with immunoglobulin G). ALP production by cultured MC3T3-E1 was enhanced in combination with PECAM-1+ EOMA (1.8 times as much as ALP production by MC3T3-E1 alone), but not in combination with PECAM-1- ISOS-1. Anti-PECAM-1 antibody inhibited the increase in ALP production under co-culture with EOMA. CONCLUSIONS: Our data show that the reduced ALP activity after skeletal unloading is closely correlated with reduced expression of PECAM-1 in bone marrow cells. We speculate that the loss of osteogenic potential after skeletal unloading is caused by the suppression of PECAM-1 signaling on endothelial cellular surface.


Assuntos
Plaquetas/metabolismo , Células da Medula Óssea/citologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/biossíntese , Células 3T3 , Fosfatase Alcalina/metabolismo , Angiopoietina-1/biossíntese , Angiopoietina-2/biossíntese , Animais , Peso Corporal , Desenvolvimento Ósseo , Técnicas de Cocultura , Regulação para Baixo , Células Endoteliais/citologia , Endotélio Vascular/metabolismo , Citometria de Fluxo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica , Osteoblastos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células-Tronco , Temperatura , Tíbia/citologia , Tíbia/metabolismo , Fatores de Tempo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/biossíntese
14.
Exp Cell Res ; 288(1): 189-97, 2003 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-12878170

RESUMO

For cancer metastasis, tumor cells present in the circulation must first adhere to the endothelium. Integrins play a central role in leukocyte adhesion to the endothelium and subsequent migration into tissues. The majority of tumor cells derived from solid cancers, including breast cancer, do not express integrins. We investigated the mechanisms of adhesion and transendothelial migration of cancer cells using breast carcinoma cell lines. Our results showed the following features of breast cancer cells: (1) HGF stimulated breast cancer cells by up-regulating CD44 expression in a concentration-dependent manner. (2) the maximum level of HGF-induced CD44 up-regulation on breast cancer cell lines occurred within 3 h. (3) HGF-induced up-regulation of CD44 was mediated by the tyrosine kinase signaling pathway. (4) HGF induced CD44-mediated adhesion of tumor cell lines to bone marrow-derived endothelial cells. (5) HGF did not change rolling of breast cancer cell lines on bone marrow-derived endothelial cells, but enhanced firm adhesion of cancer cells on endothelial cells under shear stress conditions. (6) HGF increased transendothelial migration of cancer cells. Our results indicate that HGF stimulates CD44-mediated adhesion of breast cancer cells to bone marrow-derived endothelial cells, which subsequently results in transendothelial migration of tumor cells. These results suggest that CD44 may confer the metastatic properties of breast cancer cells and, therefore, could be used as a target in future molecular cancer therapy.


Assuntos
Neoplasias da Mama/patologia , Endotélio Vascular/citologia , Fator de Crescimento de Hepatócito/farmacologia , Receptores de Hialuronatos/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Movimento Celular , Relação Dose-Resposta a Droga , Humanos , Receptores de Hialuronatos/biossíntese , Receptores de Hialuronatos/fisiologia , Cinética , Transdução de Sinais , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacos
15.
Biochem Biophys Res Commun ; 305(2): 380-5, 2003 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-12745086

RESUMO

Accumulation of monocytes and the entrapment of oxidized-low-density lipoprotein (ox-LDL) in monocytes are important in the differentiation into "foam" macrophages and the pathogenesis of atherosclerosis. We investigated the role of monocyte chemoattractant protein-1 (MCP-1) in the expression of scavenger receptor (SCR) by using resting monocytes prepared by counterflow centrifugal elutriation. Our results showed that: (1) MCP-1 increased the expression of CD36 SCR by flow cytometric analysis. (2) MCP-1 increased incorporation of 125I-labeled ox-LDL and oil red O staining. (3) MCP-1 and ox-LDL enhanced in vitro transendothelial monocyte migration. (4) These functions were mediated at least in part via extracellular signal-regulated kinase (ERK) pathway. (5) MCP-1 and ox-LDL did not induce monocyte proliferation. Our results imply that MCP-1 is involved in the inflammatory process of atherosclerosis through the induction of SCR expression via the ERK pathway and differentiation of monocytes into foam macrophages, as well as induction of monocyte migration.


Assuntos
Antígenos CD36/biossíntese , Quimiocina CCL2/farmacologia , Células Espumosas/citologia , Proteínas de Membrana , Monócitos/metabolismo , Monócitos/fisiologia , Receptores Imunológicos/biossíntese , Receptores de Lipoproteínas , Diferenciação Celular , Divisão Celular , Células Cultivadas , Quimiotaxia de Leucócito , Inibidores Enzimáticos/farmacologia , Humanos , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Receptores Depuradores , Receptores Depuradores Classe B
16.
Atherosclerosis ; 160(2): 281-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11849649

RESUMO

Inflammatory and immune responses are highly relevant processes in the pathogenesis of atherosclerosis, as illustrated by the central event of monocyte accumulation in atherosclerotic plaques. Integrin LFA-1-mediated adhesion of circulating monocytes to the endothelium is a prerequisite for recruitment of monocytes to these areas. Integrin-mediated adhesion is tightly regulated and integrins are only functional in response to particular monocyte activation stimuli. We investigated the role of oxidized low-density lipoprotein (LDL) in adhesion of resting monocytes prepared by elutriation from endothelium. Our results showed that: (1) oxidized LDL (and MCP-1) induced both LFA-1-mediated adhesion of monocytes to endothelial cells and transendothelial migration of monocytes; (2) oxidized LDL functionally transformed monocyte LFA-1 to an activated form; (3) oxidized LDL induced F-actin polymerization and cytoskeletal rearrangement within seconds; and (4) the LDL-associated antioxidant, alpha-tocopherol, but not beta-tocopherol, inhibited both F-actin polymerization and LFA-1-mediated adhesion of monocytes, which paralleled the effect of protein kinase C (PKC) inhibitors. Our results indicate that oxidized LDL plays a pivotal role in triggering LFA-1 activation and LFA-1-mediated adhesion and transmigration of monocytes to sites of atherosclerotic plaques, via the PKC pathway.


Assuntos
Endotélio Vascular/fisiologia , Lipoproteínas LDL/farmacologia , Antígeno-1 Associado à Função Linfocitária/fisiologia , Monócitos/fisiologia , Proteína Quinase C/fisiologia , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/farmacologia , Quimiotaxia de Leucócito/efeitos dos fármacos , Epitopos , Humanos , Oxirredução , alfa-Tocoferol/farmacologia
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