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1.
J Biomed Inform ; 108: 103499, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32653620

RESUMO

According to Ministry of Health and Welfare of Taiwan, cancer has been one of the major causes of death in Taiwan since 1982. The Intensive-Modulated Radiation Therapy (IMRT) is one of the most important radiotherapies of cancers, especially for Nasopharyngeal cancers, Digestive system cancers and Cervical cancers. For patients, if they can receive the treatment at the earliest possibility while diagnosed with cancers, their survival rate increases. However, the discussion of effective patient scheduling models of IMRT to reduce patients' waiting time is still limited in literature. This study proposed a mathematical model to improve the efficiency of patient scheduling. The research was composed of two stages. In the first stage, the online stochastic algorithm was proposed to improve the performance of present scheduling system. In the second stage the impact of future treatment to reduce patients' waiting time was considered. A genetic algorithm (GA) was then proposed to solve the online stochastic scheduling problem. This research collected data from a practical medical institute and the proposed model was validated with real data. It contributes to both theory and practice by proposing a practical model to assist the medical institute in implementing patient scheduling in a more efficient manner.


Assuntos
Radioterapia de Intensidade Modulada , Algoritmos , Agendamento de Consultas , Humanos , Modelos Teóricos , Planejamento da Radioterapia Assistida por Computador , Taiwan
2.
Oncogene ; 35(43): 5674-5685, 2016 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-27065329

RESUMO

HLJ1 (DNAJB4), a DNAJ/Hsp40 chaperone, has emerged as a novel prognostic marker in lung cancers; however, the molecular contribution and functionality in neoplastic diseases remain to be established. This study demonstrated that HLJ1 inhibits epithelial-mesenchymal transition in vitro and reduces lung cancer metastasis in vivo. Using shRNA silencing and ectopic expression of HLJ1, we found that HLJ1 not only suppresses catalytic activity of Src but also downregulates the formation of oncogenic complexes associated with the EGFR, FAK and STAT3 signaling pathways. A screen of specimens from HLJ1-knockout mice and lung cancer patients validated that HLJ1 expression is inversely correlated with Src activity. Mechanistically, HLJ1 protein directly bound to catalytic and protein-binding domains of Src through its amino acid Y172 and the P301/P304 motif. Following Src-induced HLJ1 phosphorylation at Y172, HLJ1-Src interaction was elevated, resulting in Src inhibition and malignancy suppression. Interestingly, both Src-binding regions also occurred in other DNAJB family members and contributed to anti-invasive activities of DNAJB proteins. We conclude that HLJ1 is an endogenous Src inhibitor that can suppress cancer metastasis through complex interacting mechanisms. This HLJ1-Src complex might provide a promising molecular model for developing new anticancer strategies.


Assuntos
Proteínas de Choque Térmico HSP40/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Quinases da Família src/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Modelos Animais de Doenças , Progressão da Doença , Ativação Enzimática , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/farmacologia , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Knockout , Modelos Biológicos , Modelos Moleculares , Mutação , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias/genética , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Interferência de RNA , RNA Interferente Pequeno/genética , Domínios de Homologia de src , Quinases da Família src/química , Quinases da Família src/metabolismo
3.
Clin Otolaryngol ; 41(5): 498-510, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26436726

RESUMO

BACKGROUND: Use of polysomnography (PSG) is the gold standard of diagnosis and measurement of treatment effectiveness for paediatric obstructive sleep apnoea (OSA). Although adenotonsillectomy (T&A) is effective in diminishing the apnoea-hypopnoea index (AHI), a meta-analysis of postoperative changes for all other PSG parameters and outcome comparisons between obese and non-obese children following T&A have never been conducted. OBJECTIVE OF REVIEW: To comprehensively review polysomnographic findings after surgery for obese and non-obese children with OSA. SEARCH STRATEGY: Study protocol was registered on PROSPERO (CRD42013004737). Two authors independently searched databases including PubMed, MEDLINE, EMBASE and Cochrane Review from January 1997 to July 2014. The keywords used included the following: sleep apnea, OSA, sleep apnea syndromes, tonsillectomy, adenoidectomy, infant, child, adolescent, and Humans. EVALUATION METHOD: A comprehensive systematic review and meta-analysis for literature for OSA children treated by T&A with polysomnography data. Random-effects model was applied to determine postoperative sleep parameter changes and the surgical success rate between obese and non-obese groups. The quality of studies was assessed using the Newcastle-Ottawa Scale. RESULTS: In total, 51 studies with 3413 subjects were enrolled. After surgery, sleep architecture was altered by a significant decrease in sleep stage 1, and an increase in slow-wave sleep and the rapid eye movement stage, and enhanced sleep efficiency. The mean difference between pre- and postoperative was a significant reduction of 12.4 event/h in AHI, along with a reduction of obstructive index, hypopnoea index, central index and arousal index. Mean and minimum oxygen saturation increased significantly after surgery. The overall success rate was 51% for postoperative AHI <1 (obese versus non-obese versus combined, 34% versus 49% versus 56%), and 81% for AHI <5 (obese versus non-obese versus combined, 61% versus 87% versus 84%). Meta-regression analyses demonstrate that postoperative AHI was positively correlated with AHI and body mass index z score before surgery. CONCLUSIONS: Meta-analysis of current literature shows T&A offers prominent improvement in a variety of sleep parameters. Improvements in non-obese children exceeded those for obese children. Postoperative residual OSA remained in roughly half of the children, especially those with severe disease and obesity, making additional treatment strategies and/or long-term follow-up highly desirable.


Assuntos
Adenoidectomia , Obesidade Infantil/complicações , Apneia Obstrutiva do Sono/etiologia , Apneia Obstrutiva do Sono/cirurgia , Tonsilectomia , Criança , Humanos , Polissonografia , Resultado do Tratamento
4.
Poult Sci ; 93(11): 2802-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25172930

RESUMO

To explore regulation of inosinic acid content in chicken meat as a result of feed additives, 576 one-day-old male Arbor Acres broilers were randomly allotted into 8 dietary treatments including control, purine nucleotide (P), betaine (B), soybean isoflavone (S), purine nucleotide + betaine (PB), purine nucleotide + soybean isoflavone (PS), betaine +soybean isoflavone (BS), and purine nucleotide + betaine + soybean isoflavone (PBS) by a 2 × 2 × 2 factorial arrangement. At d 42 of age, broilers were slaughtered, and growth performance, carcass characteristics, inosinic acid content, and activities of enzyme closely related to inosinic acid metabolism of broilers were measured. The results revealed that these feed additives did not affect ADG and ADFI of the broilers (P > 0.05). However, supplementing purine nucleotides lowered feed/gain of broilers in PS and PBS groups (P < 0.05). There was a significant interaction on feed/gain of broilers between purine nucleotides and soybean isoflavone (P < 0.05). The abdominal fat percentages in groups B, S, BS, and PBS were lower than the control group, respectively (P < 0.05). The thigh muscle percentages of groups P and B were higher than that of group PB (P < 0.05). There were certain interactions on the percentage of thigh muscle (P = 0.05) and abdominal fat (P < 0.05) between P, B, and S groups. Compared with the control group, inosinic acid content in broiler breast meat was improved by using feed additives (P < 0.05). Supplementing purine nucleotides, betaine, soybean isoflavone, and their combinations increased alkaline phosphatase activity in breast meat of broilers (P < 0.05). Purine nucleotides improved the activity of adenosine deaminase, but decreased the activity of 5'-nucleotidase. Soybean isoflavone lowered the activity of alkaline phosphatase. There were no significant interactions on activities of creatine kinase, adenosine deaminase, alkaline phosphatase, and 5'-nucleotidase between these additives (P > 0.05). The umami rating of broiler breast meat increased in conjunction with supplementing these additives. In conclusion, supplementing standard feed with the additives investigated in this study could improve inosinic acid content in chicken meat by increasing synthase activity or inhibiting degradation enzyme activity without inferior growth performance and carcass quality.


Assuntos
Betaína/metabolismo , Galinhas/fisiologia , Dieta/veterinária , Inosina Monofosfato/metabolismo , Isoflavonas/metabolismo , Músculo Esquelético/química , Nucleotídeos de Purina/metabolismo , Ração Animal/análise , Animais , Betaína/administração & dosagem , Galinhas/crescimento & desenvolvimento , Suplementos Nutricionais/análise , Isoflavonas/administração & dosagem , Masculino , Carne/análise , Músculo Esquelético/enzimologia , Músculo Esquelético/fisiologia , Nucleotídeos de Purina/administração & dosagem , Distribuição Aleatória , Glycine max/química
5.
Eur J Gynaecol Oncol ; 34(5): 442-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24475579

RESUMO

PURPOSE OF INVESTIGATION: The authors sought to evaluate the feasibility and acceptability of using the thermal welding technique with thermal ligating shear (TWT-TLS)-assisted laparoscopic radical hysterectomy (LRH) and systemic pelvic lymphadenectomy (SPL) in the management of Stage IB1 squamous cell carcinoma of the cervix. MATERIALS AND METHODS: The authors compared operating time, blood loss, and other intra- and postoperative parameters and outcomes in 53 patients between May 2003 and April 2007. RESULTS: Twenty-three patients were treated with TWT-TLS-assisted LRH and SPL (TWT-TLS group) and 30 patients with abdominal radical hysterectomy (ARH) and SPL (ARH group). The surgical time of the TWT-TLS group was significantly shorter than that of the ARH group (221.4 vs 264.6 min, p < 0.05). The blood loss of the TWT-TLS group was less than that of the ARH group (195.7 vs 1,214.7 ml, p < 0.001). The immediate postoperative recovery seemed to be rapid in the TWT-TLS group compared with the ARH group (1.4 vs 3.5 days for full diet, p < 0.001; 8.32 vs 12.14 days for hospital stay, p < 0.001). The recurrence rate between the two groups was similar during the median four-year follow-up (8.7% vs 13.3%). CONCLUSIONS: TWT-TLS is a safe and efficient method for laparoscopic RH and SPL with reduction of morbidity for early-stage cervical cancer. A further study is needed to confirm the above observation.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Histerectomia/métodos , Laparoscopia/métodos , Neoplasias do Colo do Útero/cirurgia , Adulto , Idoso , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Histerectomia/instrumentação , Laparoscopia/instrumentação , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Recidiva , Neoplasias do Colo do Útero/patologia , Soldagem
6.
Clin Microbiol Infect ; 18(6): E149-57, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22439904

RESUMO

The limited sensitivity of serological tests for mycobacterial antigens has encouraged the development of a nanoparticle probe specific for the extrapulmonary form of Mycobacterium tuberculosis (Mtb). We developed an innovative probe comprised of super-paramagnetic iron oxide (SPIO) nanoparticles conjugated with Mtb surface antibody (MtbsAb-nanoparticles) to provide ultrasensitive imaging of biomarkers involved in extrapulmonary Mtb infection. MtbsAb-nanoparticles were significantly conjugated with Mtb bacilli. The extent of contrast enhancement reduction on magnetic resonance imaging (MRI) for Mtb and human monocytic THP1 cells was proportional to the concentration of MtbsAb-nanoparticles. When MtbsAb-nanoparticles were intravenously injected into mice bearing Mtb granulomas, the granulomatous site showed a 14-fold greater reduction in signal intensity enhancement on T(2) -weighted MR images compared with an opposing site that received PBS injection. Mtb sAb-nanoparticles represent a new non-invasive technology for the diagnosis of extrapulmonary Mtb.


Assuntos
Anticorpos Antibacterianos , Compostos Férricos , Mycobacterium tuberculosis/isolamento & purificação , Nanopartículas , Tuberculose/diagnóstico , Animais , Imageamento por Ressonância Magnética/métodos , Camundongos
9.
Neuroscience ; 183: 178-88, 2011 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-21459131

RESUMO

Collagen VI, one of the extracellular matrix proteins, has been implicated in regulating cell proliferation and reducing apoptosis in several different systems. However, the role of collagen VI in the central nervous system remains unclear. In this manuscript, we demonstrated that upon ultraviolet (UV) irradiation, mouse primary hippocampal neurons specifically up-regulate the expression of Col6a1, Col6a2, and Col6a3 mRNA and secreted collagen VI protein. Augmentation of collagen VI mRNA and protein after UV irradiation may have a neuroprotective role as suggested by the fact that extracellular supplying soluble collagen VI protein, but not other collagen proteins, reduced UV induced DNA damage, mitochondria dysfunction, and neurite shrinkage. We also tried to determine the signaling molecules that mediate the protective effect of collagen VI via Western blot and inhibitor analysis. After collagen VI treatment, UV irradiated neurons increased phosphorylation of Akt and decreased phosphorylation of JNK. Inhibiting Akt/phosphatidylinositol 3-kinases (PI3K) pathway diminished the protective effect of collagen VI. Our study suggested a potential protective mechanism by which neurons up-regulate collagen VI production under stress conditions to activate Akt/PI3K anti-apoptotic signaling pathway.


Assuntos
Apoptose/efeitos dos fármacos , Colágeno Tipo VI/farmacologia , Neurônios , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Raios Ultravioleta/efeitos adversos , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Colágeno Tipo VI/genética , Colágeno Tipo VI/metabolismo , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Inibidores Enzimáticos/farmacologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Hipocampo/citologia , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Endogâmicos C57BL , Neuritos/efeitos dos fármacos , Neuritos/efeitos da radiação , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Neurônios/efeitos da radiação , Gravidez , Transdução de Sinais/efeitos dos fármacos , Estatísticas não Paramétricas , Sais de Tetrazólio , Tiazóis , Fatores de Tempo
10.
Leukemia ; 24(2): 397-405, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20016538

RESUMO

The long-term outcome of 1390 children with acute lymphoblastic leukemia (ALL), treated in two successive clinical trials (Taiwan Pediatric Oncology Group (TPOG)-ALL-97 and TPOG-ALL-2002) between 1997 and 2007, is reported. The event-free survival improved significantly (P=0.0004) over this period, 69.3+/-1.9% in 1997-2001 to 77.4+/-1.7% in 2002-2007. A randomized trial in TPOG-97 testing L-asparaginase versus epidoxorubicin in combination with vincristine and prednisolone for remission induction in standard-risk (SR; low-risk) patients yielded similar outcomes. Another randomized trial, in TPOG-2002, showed that for SR patients, two reinduction courses did not improve long-term outcome over one course. Decreasing use of prophylactic cranial irradiation in the period 1997-2008 was not associated with increased rates of CNS relapse, prompting complete omission of prophylactic cranial irradiation from TPOG protocols, beginning in 2009. Decreased use of etoposide and cranial irradiation likely contributed to the low incidence of second cancers. High-risk B-lineage ALL, T-cell, CD10 negativity, t(9;22), infant, and higher leukocyte count were consistently adverse factors, whereas hyperdiploidy >50 was a consistently favorable factor. Higher leukocyte count and t(9;22) retained prognostic significance in both TPOG-97 and TPOG-2002 by multivariate analysis. Although long-term outcome in TPOG clinical trials is comparable with results being reported worldwide, the persistent strength of certain prognostic variables and the lower frequencies of favorable outcome predictors, such as ETV6-RUNX1 and hyperdiploidy >50, in Taiwanese children warrant renewed effort to cure a higher proportion of patients while preserving their quality of life.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Recidiva Local de Neoplasia/terapia , Segunda Neoplasia Primária/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Criança , Pré-Escolar , Aberrações Cromossômicas , Terapia Combinada , Irradiação Craniana , Feminino , Seguimentos , Humanos , Imunofenotipagem , Lactente , Masculino , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Neoplasia Residual , Segunda Neoplasia Primária/genética , Segunda Neoplasia Primária/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Prognóstico , Indução de Remissão , Fatores de Risco , Taxa de Sobrevida , Taiwan , Fatores de Tempo , Resultado do Tratamento
11.
J Bone Joint Surg Br ; 91(8): 1094-6, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19651842

RESUMO

We report the case of a 24-year-old man with a congenital meniscoid articular disc of the triangular fibrocartilage complex with extensor carpi ulnaris tenosynovitis. His young age, the normal articular cartilage, the lack of degenerative changes at the margins of the defect and its bilateral occurrence made this diagnosis likely. A congenital defect of the articular disc of the triangular fibrocartilage complex should not be misinterpreted as a traumatic rupture and is usually asymptomatic.


Assuntos
Tenossinovite/diagnóstico , Fibrocartilagem Triangular/anormalidades , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
13.
Neuropediatrics ; 40(6): 298-300, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20446227

RESUMO

Here, we report on a boy affected by both cerebral palsy and Becker muscular dystrophy (BMD). He had infrequently used his right hand since birth. But brain magnetic resonance imaging (MRI) taken at the age of 15 months showed no specific finding. Approximately 1 month later, muscle enzymes of his older brother were incidentally found to be elevated. The patient and his brother were diagnosed with progressive muscular dystrophy by gene analysis. At the age of 6 years, he underwent orthopedic surgery due to a right equinovarus deformity and BMD was confirmed by concomitant muscle biopsy. During the post-operative rehabilitation, clumsiness of the right hand was also observed. A follow-up brain MRI with diffusion tensor imaging (DTI) was taken. Although no responsible lesion was found on conventional MRI, DTI and fiber tractography revealed a decrease in the quantity of fibers in the left corticospinal tract. He was additionally diagnosed as having cerebral palsy.


Assuntos
Lesões Encefálicas/diagnóstico , Lesões Encefálicas/etiologia , Córtex Cerebral/patologia , Distrofia Muscular de Duchenne/complicações , Tornozelo/inervação , Tornozelo/fisiopatologia , Fenômenos Biomecânicos , Humanos , Lactente , Joelho/inervação , Joelho/fisiopatologia , Masculino , Músculo Esquelético/patologia
18.
Clin Pharmacol Ther ; 81(4): 586-94, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17235331

RESUMO

To compare the prevalence of extrapyramidal syndrome (EPS) between the first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs), the co-prescribing rate of anti-Parkinson drugs (APDs) of each antipsychotic drug was analyzed using population database. Fourteen antipsychotics had been prescribed during the 5-year study period. Among the SGAs, quetiapine had the lowest crude co-prescribing rate of APDs (27.09%), whereas risperidone had the highest rate (66.50%). Among the FGAs, thioridazine and loxapine had the lowest (60.99%) and highest rates (96.35%), respectively. The rankings of the co-prescribing rate of APDs among antipsychotics, in increasing order, were quetiapine, clozapine, olanzapine, thioridazine, zotepine, chlorpromazine, risperidone, sulpiride, clotiapine, flupentixol, haloperidol, zuclopentixol, trifluoperazine, and loxapine. The results indicate that the risk of EPS appears to be lower in SGAs than in FGAs; however, the considerably high rate of EPS in some of the newer generation of antipsychotics warrants clinical attention.


Assuntos
Antipsicóticos/efeitos adversos , Discinesia Induzida por Medicamentos/epidemiologia , Esquizofrenia/complicações , Adulto , Antidiscinéticos/uso terapêutico , Antidepressivos/efeitos adversos , Antidepressivos/uso terapêutico , Antimaníacos/efeitos adversos , Antimaníacos/uso terapêutico , Uso de Medicamentos , Discinesia Induzida por Medicamentos/tratamento farmacológico , Feminino , Humanos , Hipnóticos e Sedativos/efeitos adversos , Hipnóticos e Sedativos/uso terapêutico , Masculino , Programas Nacionais de Saúde/estatística & dados numéricos , População , Risco , Taiwan/epidemiologia
19.
Apoptosis ; 11(10): 1773-88, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16927018

RESUMO

Antizymes delicately regulate ornithine decarboxylase (ODC) enzyme activity and polyamine transportation. One member of the family, antizyme-1, plays vital roles in molecular and cellular functions, including developmental regulation, cell cycle, proliferation, cell death, differentiation and tumorigenesis. However, the question of how does it participate in the cell apoptotic mechanism is still unsolved. To elucidate the contribution of human antizyme-1 in haematopoietic cell death, we examine whether inducible overexpression of antizyme enhances apoptotic cell death. Antizyme reduced the viability in a dose- and time-dependent manner of human leukemia HL-60 cells, acute T leukemia Jurkat cells and mouse macrophage RAW 264.7 cells. The apoptosis-inducing activities were determined by nuclear condensation, DNA fragmentation, sub-G(1) appearance, loss of mitochondrial membrane potential (Deltapsi( m )), release of mitochondrial cytochrome c into cytoplasm and proteolytic activation of caspase 9 and 3. Following conditional antizyme overexpression, all protein levels of cyclin-dependent kinases (Cdks) and cyclins are not significantly reduced, except cyclin D, before their entrance into apoptotic cell death. However, introduced cyclin D1 into Jurkat T tetracycline (Tet)-On cell system still couldn't rescue cells from apoptosis. Antizyme doesn't influence the expression of tumor suppressor p53 and its downstream p21, but it interferes in the expressions of Bcl-2 family. Inducible antizyme largely enters mitochondria resulting in cytochrome c release from mitochondria to cytosol following Bcl-xL decrease and Bax increase. According to these data, we suggest that antizyme induces apoptosis mainly through mitochondria-mediated and cell cycle-independent pathway. Furthermore, antizyme induces apoptosis not only by Bax accumulation reducing the function of the Bcl-2 family, destroying the Deltapsi( m ), and releasing cytochrome c to cytoplasm but also by the activation of apoptosomal caspase cascade.


Assuntos
Apoptose/fisiologia , Caspases/fisiologia , Sistema Hematopoético/fisiologia , Potenciais da Membrana/fisiologia , Membranas Mitocondriais/fisiologia , Proteínas/fisiologia , Animais , Caspase 3/metabolismo , Ciclina D , Ciclina D1/genética , Ciclina D1/metabolismo , Ciclinas/metabolismo , Citocromos c/metabolismo , Células HL-60 , Humanos , Células Jurkat , Camundongos , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Ornitina Descarboxilase/metabolismo , Inibidores da Ornitina Descarboxilase , Poli(ADP-Ribose) Polimerases/metabolismo , Transporte Proteico , Proteínas/genética , Proteínas/metabolismo , Transfecção , Transgenes/genética , Células Tumorais Cultivadas , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismo
20.
Apoptosis ; 11(3): 389-99, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16520895

RESUMO

Prolactin has more than 300 separate functions including affecting mammary growth, differentiation, secretion and anti-apoptosis. In the previous studies, prolactin induced Bcl-2 expression to prevent apoptosis and also provoked the activity of ornithine decarboxylase (ODC). Our previous data showed that ODC overexpression upregulates Bcl-2 and prevents tumor necrosis factor alpha (TNF-alpha)- and methotrexate (MTX)-induced apoptosis. Here, we further investigate whether prolactin prevents MTX-induced apoptosis through inducing ODC activity and the relationship between ODC and Bcl-2 upon prolactin stimulation. Prolactin prevented MTX-induced apoptosis in a dose-dependent manner in HL-60 cells. Following prolactin stimulation, ODC enzyme activity also shows an increase in a dose-dependent manner, expressing its maximum level at 3 h, and rapidly declining thereafter. Prolactin-induced ODC activity is completely blocked by a protein kinase C delta (PKCdelta) inhibitor, rottlerin. However, there are no changes in the expressions of ODC mRNA and protein level after prolactin stimulus. It indicates that prolactin may induce ODC activity through the PCKdelta pathway. Besides, Bcl-2 expresses within 1 h of prolactin treatment and this initiating effect of prolactin is not inhibited by alpha-difluoromethylornithine (DFMO). However, Bcl-2 is further enhanced following prolactin stimulation for 4 h and this enhancement is blocked by DFMO. Bcl-2 has no effect on ODC activity and protein levels, but ODC upregulates Bcl-2, which is inhibited by DFMO. Overall, there are two different forms of prolactin effect, it induces Bcl-2 primarily, and following this it stimulates ODC activity. Consequently induced ODC activity further enhances the expression of Bcl-2. The anti-apoptotic effect of prolactin is diminished by DFMO and recovered by putrescine. Obviously, ODC activity is one basis for the anti-apoptotic mechanisms of prolactin. A Bcl-2 inhibitor, HA14-1, together with DFMO, completely blocks the anti-apoptotic effects of prolactin. These results suggest that increasing ODC activity is another way of prolactin preventing MTX-induced apoptosis and that this induction of ODC activity enhances the expression of Bcl-2 strongly enough to bring about the anti-apoptotic function.


Assuntos
Apoptose/fisiologia , Antagonistas do Ácido Fólico/metabolismo , Metotrexato/metabolismo , Ornitina Descarboxilase/metabolismo , Prolactina/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Apoptose/efeitos dos fármacos , Fragmentação do DNA , Relação Dose-Resposta a Droga , Células HL-60 , Humanos , Metotrexato/farmacologia , Ornitina Descarboxilase/genética , Prolactina/farmacologia , Regulação para Cima , Proteína bcl-X/metabolismo
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