RESUMO
Background and study aims: The long-term comprehensive prognosis of chronic hepatitis C after direct-acting antiviral (DAA) therapy is unclear. This study aimed to investigate the prognosis and incidence of immunological and oncological complications after DAA therapy. Patients and methods: The study included a total of 1461 patients who received DAA therapy in our university hospital and affiliated hospitals between September 3, 2014 and September 30, 2018. Results: The incidence rates of total malignancies in overall or female patients after DAA therapy were significantly greater than expected in the corresponding general population. The same was true for lung malignancies. Predictive risk factors associated with the occurrence and recurrence of hepatic malignancies after DAA therapy in patients with sustained virological response were cirrhosis and insulin use, protein induced by vitamin K absence or antagonist-II level, and albumin-bilirubin score, respectively. Eight (0.5%) patients were diagnosed with autoimmune diseases after starting DAA therapy. Importantly, the attending physician considered a possible causal relationship between DAA therapy and these autoimmune diseases in five cases (four rheumatoid arthritis and one membranoproliferative glomerulonephritis). The 5-year overall survival rate was 91.6%. The most frequent primary cause of death was malignancy in 41 (60.2%) patients, including 25 with hepatic malignancies. Lung and colorectal cancers were the next most common. Conclusions: Given that the incidence of total and lung cancers might increase and DAA-related autoimmune diseases might emerge after DAA therapy, we should be alert for the development of these diseases as well as hepatic malignancies.
Assuntos
Carcinoma Hepatocelular , Hepatite C Crônica , Hepatite C , Neoplasias Hepáticas , Humanos , Feminino , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/complicações , Antivirais/efeitos adversos , Carcinoma Hepatocelular/tratamento farmacológico , Incidência , Neoplasias Hepáticas/tratamento farmacológico , Prognóstico , Hepatite C/tratamento farmacológicoAssuntos
Anticorpos Monoclonais Humanizados , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/enzimologia , Compostos Organometálicos , Compostos Radiofarmacêuticos , Receptor ErbB-2/biossíntese , Feminino , Humanos , Imuno-Histoquímica , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , TrastuzumabRESUMO
A 35-year-old male had advanced nonseminomatous germ cell tumor (stage IIIC, embryonal cell carcinoma) which proved refractory to conventional PVB combined chemotherapy. He was then treated with an ultra high-dose chemotherapy consisting of carboplatin (1.5 g/m2) and etoposide (1.3 g/m2), followed by the transplantation of peripheral blood stem cells (PBSCT) with a total of 1.9 x 10(5)/kg granulocyte colony-forming cells (CFU-GM). Because he developed lung metastasis, escalated doses of carboplatin (2.0 g/m2), and etoposide (1.8 g/m2) combined with cyclophosphamide (7.0 g/m2) were given with peripheral blood stem cell transplant of 3.2 x 10(5)/kg CFU-GM. He has remained free of any recurrence without maintenance therapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Embrionário/terapia , Transplante de Células-Tronco Hematopoéticas , Neoplasias Testiculares/terapia , Adulto , Carboplatina/administração & dosagem , Carcinoma Embrionário/patologia , Carcinoma Embrionário/secundário , Terapia Combinada , Ciclofosfamida/administração & dosagem , Etoposídeo/administração & dosagem , Humanos , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Masculino , Indução de Remissão , Neoplasias Testiculares/patologia , Transplante AutólogoRESUMO
A vacuolar H(+)-translocating inorganic pyrophosphatase was purified from pear fruit through selective detergent treatments, Superose 6 and Mono Q column chromatography. The specific activity of the purified enzyme was 850 mumol h-1 mg protein-1. The Mr of V-PPase was 66 kDa by SDS-PAGE and the polypeptide cross-reacted with the antiserum against V-PPase of mung bean. The purified V-PPase was stimulated by potassium and inhibited by calcium and N, N'-dicyclohexylcarbodiimide.
Assuntos
Frutas/enzimologia , Pirofosfatases/isolamento & purificação , Vacúolos/enzimologia , Western Blotting , Cromatografia em Gel , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Pirofosfatase Inorgânica , Pirofosfatases/antagonistas & inibidores , Pirofosfatases/metabolismo , SolubilidadeRESUMO
BACKGROUND: L-Arginine (L-Arg), one of the essential amino acids, has been reported to have an immunomodulatory effect. The precise mechanism of the L-Arg-induced natural killer (NK) cell activation remains unresolved,and the effect of L-Arg on NK cells in chronic fatigue syndrome (CFS) patients has not been estimated. METHODS: NK cell function was evaluated in 20 subjects with CFS and compared with that in 21 healthy individuals. RESULTS: In healthy control subjects, NK activity was significantly increased after treatment with L-Arg, an NK function enhancer, for 24 h, whereas the same treatment failed to enhance NK activity in the CFS patients. We thus focused on L-Arg metabolism, which involves nitric oxide (NO) production through NO synthase (NOS). The expression of inducible NO synthase (iNOS) transcripts in peripheral blood mononuclear cells was not significantly different between healthy control subjects and CFS patients. The L-Arg-mediated NK cell activation was abolished by addition of NG-monomethyl-L-arginine, an inhibitor for iNOS. Furthermore, incubation with S-nitroso-N-acetyl-penicillamine, an NO donor, stimulated NK activity in healthy control subjects but not in CFS patients. CONCLUSION: These results demonstrate that the L-Arg-induced activation of NK activity is mediated by NO and that a possible dysfunction exists in the NO-mediated NK cell activation in CFS patients.
Assuntos
Síndrome de Fadiga Crônica/imunologia , Células Matadoras Naturais/imunologia , Óxido Nítrico/imunologia , Adjuvantes Imunológicos/metabolismo , Adjuvantes Imunológicos/farmacologia , Adulto , Arginina/metabolismo , Arginina/farmacologia , Sequência de Bases , Estudos de Casos e Controles , Primers do DNA/genética , Inibidores Enzimáticos/farmacologia , Síndrome de Fadiga Crônica/genética , Síndrome de Fadiga Crônica/metabolismo , Feminino , Humanos , Técnicas In Vitro , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/metabolismo , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Masculino , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase Tipo II , Penicilamina/análogos & derivados , Penicilamina/farmacologia , S-Nitroso-N-Acetilpenicilamina , ômega-N-Metilarginina/farmacologiaRESUMO
Intermittent intestinal bleeding persisted in a 77-year-old male, who had undergone grafting for abdominal aortic aneurysm. Each attack lasted for a few weeks and spontaneously resolved. Only a minute abnormality was found in the third portion of the duodenum; barium studies showed a segmental narrowing, but endoscopy disclosed only a small erosion in that portion. Massive and fatal gastrointestinal hemorrhage broke out 6 months after the onset of bleeding. Autopsy revealed an adhesion area with a small fistula formation between the duodenum and aorta. Even slight endoscopic findings should be considered suggestive of aortoenteric fistula in patients after aortic surgery.
Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Doenças da Aorta/etiologia , Duodenopatias/etiologia , Hemorragia Gastrointestinal/etiologia , Fístula Intestinal/etiologia , Complicações Pós-Operatórias/etiologia , Fístula Vascular/etiologia , Idoso , Doenças da Aorta/diagnóstico , Implante de Prótese Vascular/efeitos adversos , Duodenopatias/diagnóstico , Duodenoscopia , Evolução Fatal , Humanos , Fístula Intestinal/diagnóstico , Masculino , Complicações Pós-Operatórias/diagnóstico , Fístula Vascular/diagnósticoRESUMO
Vacuolar H(+)-ATPase (V-ATPase) was purified from pear fruit and antibodies were raised against the subunits of 55 and 33 kDa. Antibodies against mung bean H(+)-pyrophosphatase (V-PPase) and radish VM23, which is a tonoplast intrinsic protein (TIP) and a water channel, cross-reacted with the vacuolar membrane proteins of pear fruit. To clarify the roles of these proteins in development of pear fruit, we determined their levels relative to the total amount of protein by immunoblot analysis. The levels of subunits of the V-ATPase increased with fruit development. By contrast, the level of V-PPase was particularly high at the cell-division stage and remained almost the same at other stages. The changes in the activities of V-ATPase and V-PPase corresponded to those in their protein levels. The ratio of V-PPase activity to V-ATPase activity indicated that V-PPase is a major H(+)-pump of the vacuolar membranes of young fruit and that the contribution of V-ATPase increases with fruit development, finally, V-ATPase becomes the major H(+)-pump during the later stages of fruit development. The level of a protein analogous to VM23 (VM23P) was especially high during the active cell-expansion stage in young fruit, and VM23P might, therefore, play an important role in the rapid expansion of cells as a vacuolar water channel. Our results show that the levels of V-ATPase, V-PPase and VM23P change differently and reflect the roles of the respective protein in the development of pear fruit.
Assuntos
Frutas/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Plantas/metabolismo , ATPases Vacuolares Próton-Translocadoras , Adenosina Trifosfatases/metabolismo , Animais , Formação de Anticorpos , Membrana Celular/metabolismo , Reações Cruzadas , Fabaceae/enzimologia , Frutas/crescimento & desenvolvimento , Pirofosfatase Inorgânica , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas de Plantas/imunologia , Plantas Medicinais , Bombas de Próton , ATPases Translocadoras de Prótons/imunologia , ATPases Translocadoras de Prótons/metabolismo , Pirofosfatases/imunologia , Pirofosfatases/metabolismo , Rosales/crescimento & desenvolvimento , Rosales/metabolismo , Vacúolos/metabolismo , VerdurasRESUMO
A report is presented of a follicular dendritic cell (FDC) tumor arising in the lymph nodes and inguen of a 55-year-old Japanese female, who had suffered from schizophrenia for 25 years. The left submandibular lymph nodes had completely lost their normal architecture, except for the capsule, due to tumor cell infiltration. Occasional nodular structures resembling epithelioid granulomas, attributable, at least in part, to follicular involvement of tumor cells, were observed. These nodules were composed of epithelioid- or fibroblast-like tumor cells forming interwoven fascicles, to which small lymphocytes were attached. Tumor cells were also scattered in the internodular areas. For more atypical tumor cells, arranged in a sheet-like structure, were present in the inguinal specimen, the tumor cells of which expressed Ki-M4p, CD21, CD35 and other antigens known to be expressed on FDC. Furthermore, they also expressed the monocyte/macrophage antigens, alpha 1-antitrypsin, alpha 1-antichymotrypsin, lysozyme, CD14, CD33, CD68 and Mac387 and fibroblastic antigen. Ultrastructural studies demonstrated lysosomal granules as well as a few desmosomes, indicating the tumor cells possessed fibrohistiocytic and FDC characteristics.
Assuntos
Células Dendríticas/patologia , Fibroblastos/imunologia , Histiócitos/imunologia , Linfonodos/patologia , Metástase Linfática/patologia , Biomarcadores/análise , Biópsia , Feminino , Humanos , Imuno-Histoquímica , Linfonodos/ultraestrutura , Microscopia Eletrônica , Pessoa de Meia-Idade , Esquizofrenia/complicaçõesRESUMO
We investigated the therapeutic efficacy and safety of cefpirome sulfate (CPR) in treatment of hematopoietic disorder-associated infections. A total of 219 patients were admitted to 12 hospitals of Hanshin Study Group of hematopoietic disorders and infections between April 1994 and March 1996 and were enrolled in this study. Most patients received intravenously infused CPR at a dose of 1 or 2 g twice a day for 3 days or more. Twenty nine patients dropped out or were excluded and remaining 190 patients were adopted for the evaluation. A overall response rate was 58.4% (111/190). Among neutropenic patients, the response rate was 50% (8/16) in patients whose peripheral neutrophil counts (PNC) remained less than 100/microliter throughout the observation period and was 53.7% (22/41) in patients with PNC remained less than 500/microliter. In contrast, in patient whose PNC was below 500 before the treatment but exceeded 501/microliter during of at the end of the treatment, the response rate was as high as 78.4% (29/37). When G-CSF was combined, the response rate became significantly (P < 0.05) higher, 68.5% (50/73), as compared with that, 52.1% (61/117), in patients without it. In cases in which the causative organisms could be identified, the organisms were eliminated in 81.8% (9/11) of the patients infected with Gram-positive bacteria, whereas in 100% (12/12) in those infected with Gram-negative bacteria. Skin eruption developed in 6 patients during the treatment with CPR, and vascular pain and parosmia in one each other. These symptoms subsided soon after discontinuation or even without discontinuation of CPR. Abnormal laboratory findings, mainly liver dysfunction, i.e. elevation of slight degree of serum transaminase levels, were observed. The values, however, turned to normal immediately after the cessation or completion of the treatment. In conclusion, CPR is considered to be an antibiotic of value with high efficacy and safety in treatment of hematopoietic disorder-associated infections.
Assuntos
Infecções Bacterianas/tratamento farmacológico , Cefalosporinas/administração & dosagem , Doenças Hematológicas/complicações , Infecções Oportunistas/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções Bacterianas/complicações , Cefalosporinas/efeitos adversos , Quimioterapia Combinada , Feminino , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Infecções Oportunistas/complicações , CefpiromaRESUMO
The molecular mechanism underlying the interaction between myeloma cells and stromal cells was investigated by using a human myeloma cell line (OPM-2) and human umbilical vein endothelial cells (HUVECs). Adhesion of OPM-2 cells to HUVECs was found to be significantly augmented with treatment of OPM-2 cells with an alpha-glycosidase inhibitor, castanospermine (CSP). The treatment of OPM-2 cells with CSP resulted in alteration of oligosaccharide structures of cell surface glycoproteins particularly at molecular weight of 220 kD (GP220). To determine if GP220 was involved in the adhesion of OPM-2 cells to HUVECs, cell surface glycoproteins of HUVECs were labeled by biotin and were incubated with the PVDF membrane to which cell surface glycoproteins of OPM-2 cells were blotted. The biotinylated glycoproteins at the plasma membrane of HUVECs specifically bound to GP220 of OPM-2 cells. Purification and partial amino acid sequencing of GP220 revealed that GP220 had a structure homologous to cation-independent mannose 6-phosphate/insulin-like growth factor-II (CIM6P/IGF-II) receptor. Furthermore, an antibody against CIM6P/IGF-II receptor was reactive with GP220, indicating that GP220 was a CIM6P/IGF-II receptor. The adhesion of OPM-2 cells to HUVECs was inhibited by mannose 6-phosphate. Moreover, M6P was found to suppress the adhesion of human myeloma cell lines, OPM-2 and RPMI 8226, to bone marrow stromal cells that was established from the patients with multiple myeloma. In addition, proliferation of OPM-2 was stimulated in response to IGF-II. These results suggest that CIM6P/IGF-II receptor may be functional in terms of supporting cell adhesion and proliferation of myeloma cells.
Assuntos
Endotélio Vascular/citologia , Mieloma Múltiplo/patologia , Receptor IGF Tipo 2/metabolismo , Adesão Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Humanos , Fator de Crescimento Insulin-Like II/metabolismo , Manosefosfatos/farmacologia , Mieloma Múltiplo/metabolismo , Células Tumorais CultivadasRESUMO
Lovastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, inhibits the synthesis of mevalonic acid and is widely used as an anti-atherosclerotic drug. The macrophage scavenger receptor (SCR), a trimeric membrane glycoprotein, is postulated to play a key role in atheroma macrophage foam cell formation. HMG-CoA reductase is involved in the control of the synthesis of glycoproteins and farnesylated proteins, including ras proteins, which are involved in the transcriptional regulation of SCR gene expression. Accordingly, we examined whether lovastatin alters the gene expression of SCRs in THP-1 cell derived human macrophages. Lovastatin (5-15 microM) caused a significant dose-related reduction in steady state levels of type-I SCR mRNA in phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells. The addition of exogenous mevalonate (1 mM) completely restored the lovastatin-induced decrease of type-I SCR mRNA levels. While the addition of the isoprenoid end-product, isopentenyl adenine (50 microM), had little effect on the type-I SCR mRNA levels in lovastatin treated cells, the addition of isoprenoid farnesol (5 microM) largely restored the lovastatin-induced decrease of type-I SCR mRNA levels. Actinomycin D treatment showed that degradation rates of type-I SCR mRNA did not differ between the THP-1 derived cells with and without lovastatin treatment. Nuclear run-on assays showed that lovastatin markedly decreased the transcription of SCR gene in the cells. These results suggest that lovastatin inhibits the transcription of type-I SCR gene by affecting mevalonate metabolism, possibly through the farnesyl-pyrophosphate related end-product(s) in the THP-1-derived macrophages.
Assuntos
Inibidores Enzimáticos/farmacologia , Expressão Gênica/efeitos dos fármacos , Lovastatina/farmacologia , Macrófagos/metabolismo , Proteínas de Membrana , Receptores Imunológicos/genética , Receptores de Lipoproteínas , Linhagem Celular , Dactinomicina/farmacologia , Farneseno Álcool/farmacologia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases , Ácido Mevalônico/farmacologia , RNA Mensageiro/metabolismo , Receptores Depuradores , Receptores Depuradores Classe B , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
The distribution of cadmium (Cd) in the organs of mice was studied using metallothionein (MT)-null transgenic mice. When mice were administered with Cd chloride at a single subcutaneous dose of 1.0 mg Cd/kg body weight, Cd accumulated mainly in the liver and kidney by 6 h after injection without any significant difference between the MT-null mice and control (C57BL/6J) mice. MT was not detected in these organs of MT-null mice both before and after Cd administration whereas MT was induced mainly in these organs of the control mice. There was a marked elimination of Cd from the liver of MT-null mice by 21 days after administration, compared with a relatively slow Cd elimination in the C57BL/6J mice. Under the condition that no significant liver or kidney damage was observed, MT was considered to play a significant role in the retention of Cd in the liver but not in the uptake of this metal.
RESUMO
A 63-year-old man with refractory anemia with excess of blasts in transformation exhibited erythroid hyperplasia, dyserythropoiesis, a del(20q) abnormality, susceptibility to bacterial infections, and a relatively short survival. Phagocytosis of erythrocytes by blast cells was observed. Erythrophagocytosis was also seen in myeloid cells, including promyelocytes, myelocytes, metamyelocytes and neutrophils. Neither the monocytes nor the macrophages showed erythrophagocytosis. This is the first report of erythrophagocytosis by blasts and myeloid cells in a patient with myelodysplastic syndrome.
Assuntos
Anemia Refratária com Excesso de Blastos/fisiopatologia , Eritrócitos , Eritropoese/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Fagocitose/fisiologia , Anemia Refratária com Excesso de Blastos/sangue , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The alteration of calcium content, Ca(2+)-ATPase activity, DNA content and DNA fragmentation in the nuclei of regenerating rat liver was investigated. Liver was surgically removed about 70% of that of sham-operated rats. The reduced liver weight by partial hepatectomy was completely restored at 3 days after the surgery. Regenerating liver significantly increased Ca(2+)-ATPase activity and DNA content in the nuclei between 1 and 5 days after hepatectomy. The nuclear calcium content was clearly increased from 2 days after hepatectomy. The increase of Ca(2+)-ATPase activity in regenerating liver was clearly inhibited by the presence of trifluoperazine (10 microM), staurosporine (2.5 microM) and dibucaine (10 microM), which are inhibitors of calmodulin and protein kinase, in the enzyme reaction mixture. However, the nuclear enzyme activity in normal rat liver was not significantly altered by these inhibitors. Meanwhile, the increase of nuclear DNA content in regenerating liver was completely blocked by the administration of trifluoperazine (2.5 mg/100 g body weight), suggesting an involvement of calmodulin. Now, the nuclear DNA fragmentation was significantly decreased in regenerating liver, suggesting that this decrease is partly contributed to the increase in nuclear DNA content. The present study clearly demonstrates that regenerating liver enhances nuclear Ca(2+)-ATPase activity and induces a corresponding elevation of nuclear calcium content. This Ca(2+)-signaling system may be involved in the regulation of nuclear DNA functions in regenerating rat liver.
Assuntos
ATPases Transportadoras de Cálcio/metabolismo , Núcleo Celular/metabolismo , DNA/metabolismo , Regeneração Hepática/fisiologia , Alcaloides/farmacologia , Animais , ATPases Transportadoras de Cálcio/antagonistas & inibidores , Calmodulina/antagonistas & inibidores , Dibucaína/farmacologia , Inibidores Enzimáticos/farmacologia , Masculino , Inibidores de Proteínas Quinases , Ratos , Ratos Wistar , Estaurosporina , Trifluoperazina/farmacologiaRESUMO
The c-kit protooncogene encodes a receptor tyrosine kinase that mediates signals required for differentiation, proliferation and survival of mast cells. We have already shown the constitutive activation of c-kit receptor tyrosine kinase (KIT) in a human mast cell leukemia line (HMC-1) and a murine mastocytoma cell line (P-815). We here examined whether such constitutive activation of KIT occurred in the rat tumor mast cell line RBL-2H3 as well, which is frequently used as a tool for studying functions of mast cells. In RBL-2H3 cells, KIT was constitutively phosphorylated on tyrosine and activated in the absence of autocrine production of its ligand, stem cell factor (SCF). Sequencing analysis revealed that one of c-kit genes of RBL-2H3 cells had a point mutation, resulting in amino acid substitution of Tyr for Asp in codon 817. When rat wild-type c-kit cDNA and mutant-type c-kit cDNA encoding KITTyr817 were transfected into cells of a human embryonic kidney cell line (293T), only mutant form KITTyr817 was constitutively phosphorylated on tyrosine and activated in the absence of SCF. Since mutations at the same Asp codon constitutively activated KIT in all the human HMC-1, murine P-815, and rat RBL-2H3 cell lines, and since the incorporation of antisense oligonucleotides of c-kit messenger RNA significantly suppressed the proliferation of RBL-2H3 cells, the activating mutations in the Asp codon of the c-kit gene appeared to be involved in neoplastic growth of mast cells.
Assuntos
Ácido Aspártico/farmacologia , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptores de Fator Estimulador de Colônias/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Complementar/genética , Humanos , Camundongos , Dados de Sequência Molecular , Mutação , Oligonucleotídeos Antissenso/antagonistas & inibidores , Oligonucleotídeos Antissenso/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-kit , Ratos , Receptores Proteína Tirosina Quinases/genética , Receptores de Fator Estimulador de Colônias/genética , Transfecção , Células Tumorais Cultivadas , Tirosina/metabolismoRESUMO
The c-kit receptor tyrosine kinase (KIT) is activated upon ligand binding, thereby leading to a variety of signaling events that play a fundamental role in hematopoiesis. In addition to ligand-dependent activation, we have previously shown that KIT is constitutively activated in a ligand-independent manner by two point mutations, Val-559-->Gly (G559) mutation in the juxtamembrane domain and Asp-814-->Val (V814) mutation in the phosphotransferase domain. To investigate the biochemical consequence and biologic significance of these mutations, retroviral vectors encoding KITG559 or KITV814 were introduced into murine pro-B-type Ba/F3 cells and myeloid FDC-P1 cells, both of which require interleukin-3 (IL-3) for their growth and survival. In the cells, KITG559 or KITV814 were found to be constitutively phophorylated on tyrosine in the absence of stem cell factor (SCF) that is a ligand for KIT. Chemical cross-linking analysis showed that a substantial fraction of the phosphorylated KITG559 underwent dimerization even in the absence of SCF, whereas the phosphorylated KITV814 did not, suggesting the distinct mechanisms underlying constitutive activation of KIT by G559 and V814 mutations. Furthermore, the cells expressing either KITG559 or KITV814 were found to show a factor-independent growth, whereas the cells expressing wild-type KIT (KITWT) proliferated in response to SCF as well as IL-3. Moreover, subcutaneous injection of Ba/F3 cells expressing KITG559 or KITV814 into nude mice resulted in production of large tumors at all sites of the injection within 2 weeks, and all nude mice quickly succumbed to leukemia and died. These results suggest that, although the mechanisms underlying constitutive activation of KITG559 or KITV814 may be different, both of the activating mutations have a function to induce a factor-independent and tumorigenic phenotype. Also, the data of this study raise the possibility that the constitutively activating mutations of c-kit may play a causal role in development of hematologic malignancies.
Assuntos
Mutação Puntual , Proteínas Proto-Oncogênicas/metabolismo , Proto-Oncogenes , Receptores Proteína Tirosina Quinases/metabolismo , Receptores de Fator Estimulador de Colônias/metabolismo , Sequência de Aminoácidos , Animais , Ácido Aspártico , Divisão Celular , Linhagem Celular , Transformação Celular Neoplásica , Transplante de Células , Feminino , Humanos , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutagênese Sítio-Dirigida , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-kit , Receptores Proteína Tirosina Quinases/biossíntese , Receptores Proteína Tirosina Quinases/genética , Receptores de Fator Estimulador de Colônias/biossíntese , Receptores de Fator Estimulador de Colônias/genética , Transfecção , ValinaRESUMO
Staurosporin, a broad-spectrum kinase inhibitor, induced cell spreading in a human colon cancer cell line, Colo 201. On collagen and laminin, cell spreading was induced in more than 90% of the cells and was dependent on very late activation antigen-3, as shown by an antibody inhibition assay. Cell spreading required divalent cations and showed the order of preference Mn2+ > Mg2+ > Ca2+. On fibronectin, only about 30% of the cells were observed to spread, and spreading occurred via a non-integrin, RGD-independent pathway. Staurosporin-induced spreading was inhibited by treatment with tyrosine kinase inhibitors herbimycin A and methyl 2,5-dihydroxycinnamate. Despite the presence of staurosporin, seven proteins (220, 175, 150, 98, 62, 58, and 45 kDa) showed increased levels of tyrosine phosphorylation in association with cell adhesion. Two of these (58 and 220 kDa) were identified by immunoprecipitation as Src product and tensin, respectively. Flow cytometric analysis showed that the Colo 201 cells expressed the alpha 2, alpha 3, alpha 6, and beta 1 chains of integrin, but expression of these chains was not influenced by staurosporin. Immunofluorescence microscopy revealed that the alpha 3 chain, diffusely expressed on the cell surface in the absence of staurosporin, was concentrated at focal adhesion plaques after staurosporin treatment. Neither alpha 2 nor alpha 6 was focalized by the treatment.
Assuntos
Alcaloides/farmacologia , Adesão Celular/efeitos dos fármacos , Integrinas/fisiologia , Proteínas dos Microfilamentos/metabolismo , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Receptores de Antígeno muito Tardio/fisiologia , Tirosina/análogos & derivados , Sequência de Aminoácidos , Cátions Bivalentes , Matriz Extracelular/metabolismo , Técnicas In Vitro , Dados de Sequência Molecular , Oligopeptídeos , Fosfotirosina , Proteínas Tirosina Quinases/metabolismo , Estaurosporina , Tensinas , Células Tumorais Cultivadas , Tirosina/metabolismoRESUMO
The expression of hepatic calcium-binding protein regucalcin mRNA was investigated in regenerating rat liver. The change of regucalcin mRNA levels was analyzed by Northern blotting, using liver regucalcin cDNA (0.9 kb with complete open reading frame). The reduced liver weight by partial hepatectomy (about 70%) was completely restored at 3 days after surgery. Regenerating liver significantly increased calcium content. Liver regucalcin mRNA levels clearly increased 1-5 days after hepatectomy, in comparison with that of sham-operated rats, although the increase was not seen 12 hr after the surgery. Increased regucalcin mRNA levels in regenerating liver were appreciably reduced by single intraperitoneal administration of actinomycin D (100 micrograms/100 g body weight), an inhibitor of transcriptional process. Moreover, the increased regucalcin mRNA levels by hepatectomy was weakened by a single intraperitoneal administration of trifluoperazine (2.5 mg/100 g), an inhibitor of Ca2+/calmodulin. These findings demonstrate that the expression of hepatic regucalcin mRNA is enhanced in regenerating rat liver.
Assuntos
Proteínas de Ligação ao Cálcio/biossíntese , Expressão Gênica , Regeneração Hepática , Fígado/metabolismo , RNA Mensageiro/biossíntese , Análise de Variância , Animais , Northern Blotting , Cálcio/metabolismo , Hidrolases de Éster Carboxílico , Dactinomicina/farmacologia , Expressão Gênica/efeitos dos fármacos , Hepatectomia , Peptídeos e Proteínas de Sinalização Intracelular , Cinética , Fígado/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Valores de Referência , Sulfotransferases , Fatores de Tempo , Trifluoperazina/farmacologiaRESUMO
The activity and mRNA expression of UDP-N-acetylglucosamine: beta-D mannoside beta-1,4-N-acetylglucosaminyl transferase III (GnT-III: EC 2.4.1.144) were investigated in hematological malignancies. GnT-III activity was elevated in patients with chronic myelogenous leukemia (CML) in blast crisis and patients with multiple myeloma (MM), as compared to normal healthy subjects and patients with other hematological malignancies including CML in chronic phase. The GnT-III transcript was the same size in leukemic cells from various hematological diseases and cell lines, while expression of the transcript was not found to correlate significantly with enzyme activity, implying that post-translational modification might regulate the activity of GnT-III. Southern-blot analysis showed no significant variation in the structure and position of the GnT-III genome, indicating that the gene is present as a single copy without isoforms. Furthermore, analyses by immunoprecipitation and Western blot revealed that high GnT-III activity in KU812 cell, a CML cell line, resulted in an increase in E4-PHA binding to CD45, a major surface glycoprotein of the leukocyte, indicating that more bisecting GlcNAc was added to CD45 catalyzed by elevated GnT-III.