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1.
Hong Kong Med J ; 28(6): 475-481, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35815480

RESUMO

INTRODUCTION: Kidney cancer, primarily renal cell carcinoma (RCC), ranks among the top 10 most common malignancies in the male population of Hong Kong. In 2019, members of two medical societies in Hong Kong formed an expert panel to establish a set of consensus statements for the management of metastatic RCC. On 22 June 2021, the same panel met to review recent evidence and reassess their positions regarding the management of advanced and metastatic RCC, with the aim of providing recommendations for physicians in Hong Kong. PARTICIPANTS: The panel included 12 experts (6 clinical oncologists and 6 urologists) who had extensive experience managing patients with RCC in Hong Kong. EVIDENCE: The panel reviewed randomised controlled trials, observational studies, systematic reviews/meta-analyses, and international clinical guidelines to address key clinical questions that were identified before the meeting. CONSENSUS PROCESS: In total, 15 key clinical questions were identified before the meeting, covering the surgical and systemic treatment of advanced or metastatic clear cell, sarcomatoid, and non-clear cell RCCs. At the meeting, the panellists voted on these questions, then discussed relevant evidence and practical considerations. CONCLUSIONS: The treatment landscape for advanced and metastatic RCC continues to evolve. More immune checkpoint inhibitor (ICI)-based combination regimens will be indicated for the treatment of metastatic clear cell RCC. There is increasing evidence concerning the benefit of adjuvant ICI treatment for resected advanced RCC. This article summarises recent evidence and expert insights regarding a series of key clinical questions about the management of advanced and metastatic RCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Masculino , Carcinoma de Células Renais/terapia , Neoplasias Renais/terapia , Hong Kong/epidemiologia , Consenso , Sociedades Médicas
2.
J Biotechnol ; 306: 89-96, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31580912

RESUMO

Exenatide, a synthetic version of exendin-4, is a glucagon-like peptide-1 receptor agonist (GLP-1RA) used for treating diabetes, but its relatively short half-life is a major disadvantage. In this study, we attempted residue-specific mono-PEGylation to the middle of the amino acid backbone to extend its in vivo half-life. Exenatide was point-mutated from Lys to Cys at the 12th residue to yield a variant (K12C), and PEG-maleimide of varying molecular weights (MW) (5, 10, 20, 40 kD) was site-specifically conjugated to yield a mono-PEGylate with branched T-shape molecular structure. In another approach, we conjugated a bis-maleimide PEG (10 kD) to the middle of two K12Cs to yield an H-shape homodimer PEGylate In vitro bioactivity assays indicated that: (1) PEGylates conjugated with higher MW PEG lead to stronger receptor binding, (2) the branched form was superior to the linear configuration in the binding, and (3) both T-shape and H-shape mono-PEGylates demonstrated better potency than the native exenatide, evidenced by lower EC50. Db/db mouse experiments to evaluate in vivo hypoglycemic activity indicated that: (1) all mono-PEGylates resulted in improved glucose tolerance compared to the native exenatide, (2) the homodimer PEGylate demonstrated much stronger hypoglycemic activity, especially during the initial period, and (3) the H-shape and T-shape mono-PEGylates (40 kD) maintained hypoglycemia for up to ca. 168 and 140 h, representing approximately 12- and 14-fold increase, respectively, compared with the native exenatide. Our findings suggest that the exenatide mono-PEGylates in unclassical molecular structures can improve in vivo pharmacokinetics properties.


Assuntos
Exenatida/química , Exenatida/farmacologia , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Polietilenoglicóis/química , Sequência de Aminoácidos , Animais , Glicemia/efeitos dos fármacos , Células CHO , Cricetulus , AMP Cíclico/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Modelos Animais de Doenças , Exenatida/genética , Exenatida/uso terapêutico , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Meia-Vida , Hipoglicemiantes/uso terapêutico , Maleimidas/química , Camundongos , Camundongos Nus , Camundongos Obesos , Peso Molecular
3.
J Biotechnol ; 303: 16-24, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31278957

RESUMO

Exenatide (Ex) is a 39-amino acid peptide of glucagon-like peptide-1 (GLP-1) receptor agonist that was approved by the FDA in 2005 as a Type II diabetes treatment. It shows a 53% homology with GLP-1 but has an extended half-life (ca. 2.4 h) relative to GLP-1 (ca. 2-3 min). In this study, to further extend its in vivo half-life, we constructed a fusion protein (Ex-(EBP)10-6xHis) using a biocompatible and inert elastin-based polypeptide (EBP) as a fusion partner. Valine was inserted into the guest position of the pentapeptide (VPGXG), no linker sequence was inserted in between the EBPs, and (EBP)10-6xHis tag was attached to the C-terminus of exenatide. By using a recombinant Saccharomyces cerevisiae expression system, the fusion protein was expressed and secreted to the broth and purified by Ni-NTA affinity chromatography. Compared with the native exenatide, the physical half-life of the fusion protein was ca. 3.7-fold extended while approximately 72% of the in-vitro insulin secreting activity was maintained. However, the biological half-life measured by a glucose tolerance test (GTT) and the hypoglycemic test in mice was not significantly different from that of the native form. The effects of EBPylation on bioactivity and half-life of the fusion protein are similar to those of PEGylation. The result suggests that the bioactivity and half-life should be carefully balanced to obtain optimal fusion proteins. We expect that EBPylation using an optimal repeat number of EBP can be an alternative to chemical modification for therapeutic biobetters with extended half-life.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Elastina/genética , Proteínas Recombinantes de Fusão/administração & dosagem , Saccharomyces cerevisiae/crescimento & desenvolvimento , Animais , Elastina/metabolismo , Exenatida/administração & dosagem , Exenatida/farmacocinética , Teste de Tolerância a Glucose , Meia-Vida , Humanos , Masculino , Camundongos , Peptídeos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacocinética , Saccharomyces cerevisiae/genética
4.
J Biotechnol ; 289: 88-92, 2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30496775

RESUMO

The phage display technique is a combinatorial technology in which random peptides are displayed on the surface of the phage; it is widely used to identify high-affinity peptides that bind to a target protein. However, this technique presents several problems due to non-specific binding of the phages and steric hindrance caused by blocking agents. To overcome these problems, we tested two modified methods and compared their screening performance with that of the conventional method. We used poly-His-tagged human epidermal growth factor receptor 2 (HER2) as a target protein and silica-coated magnetic particles (MPs) with an immobilized nickel-nitrilotriacetic acid ligand as a solid matrix. Modified method #1 (#M1) included two negative selection steps against a blocking agent (bovine serum albumin) and nude Ni-NTA MPs, after the positive selection step using immobilized HER2 on MPs in the absence of BSA. Modified method #2 (#M2) allowed the binding of phages and HER2 in solution prior to immobilizing HER2 on the MP surface. The negative selection procedure was the same between them. The binding affinity of the phages screened by #M1 and #M2 was evaluated by phage ELISA. Two phages from #M2 (#M2-4 and 5) showed the highest binding, and between them #M2-5 was selected for affinity maturation by inserting a hairpin-structured peptide between the two #M2-5 peptides. SPR study showed the HER2-binding affinity was indeed improved by ca. 2000-fold to become comparable with that of the intact antibody (trastuzumab). The modified biopanning methods combined with the dimerization maturation can be an effective way to develop antibody-mimicking peptides for affinity binding.


Assuntos
Técnicas de Visualização da Superfície Celular , Peptídeos , Receptor ErbB-2/metabolismo , Bacteriófagos , Ensaio de Imunoadsorção Enzimática , Escherichia coli/virologia , Ácido Nitrilotriacético/análogos & derivados , Compostos Organometálicos , Ligação Proteica , Dióxido de Silício
5.
Hong Kong Med J ; 24(3): 218-225, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29807949

RESUMO

INTRODUCTION: Salvage radiotherapy (SRT) provides effective biochemical control for patients with prostate cancer who have prostate specific antigen (PSA) failure after radical prostatectomy. However, the effect of SRT on long-term clinical outcomes remains unknown. Therefore, we report the natural history of patients treated with SRT. METHODS: We identified 84 Chinese patients with prostate cancer treated with SRT to the prostatic fossa alone during 2006-2017 at Tuen Mun Hospital, Hong Kong. Survival was calculated using Kaplan-Meier method. Log-rank test and Cox regression were used to determine significance of clinical parameters with outcomes. RESULTS: Median SRT dose given was 70 Gy (range, 64-76 Gy). Median pre-SRT PSA level was 0.4 ng/mL (0.2-7.4 ng/mL). After SRT, 47 (56%) patients had undetectable (<0.1 ng/mL) PSA levels. After median follow-up of 48 months (2 months to 10 years), 25 (30%) patients had further biochemical progression. Subsequently, 12 patients received androgen deprivation therapy and nine (11%) developed distant metastasis. The 5-year biochemical progression-free survival, androgen deprivation therapy-free survival and metastasis-free survival were 62.7%, 83.5% and 86.7%, respectively. Early PSA failure after radical prostatectomy (hazard ratio 7.4), negative surgical margin (hazard ratio 2.7), positive extracapsular extension (hazard ratio 4.6), and detectable PSA levels after SRT (hazard ratio 17.3) were associated with lower biochemical progression-free survival after SRT. CONCLUSIONS: High-dose SRT with intensity-modulated radiotherapy/volumetric modulated arc radiotherapy is an effective local treatment that can prevent distant metastasis and avoid the need for androgen deprivation therapy in Chinese patients who have PSA failure after radical prostatectomy.


Assuntos
Recidiva Local de Neoplasia/radioterapia , Próstata/patologia , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/radioterapia , Terapia de Salvação , Idoso , Progressão da Doença , Hong Kong/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Antígeno Prostático Específico/sangue , Prostatectomia/efeitos adversos , Neoplasias da Próstata/cirurgia , Dosagem Radioterapêutica , Análise de Sobrevida , Resultado do Tratamento
6.
Transplant Proc ; 49(6): 1344-1350, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28736005

RESUMO

BACKGROUND: Comparative outcomes of continuous renal replacement therapy during liver transplantation have not been investigated. We retrospectively compared the outcomes of intraoperative continuous renal replacement therapy with those of non-dialytic conservative treatment in patients with pretransplant renal dysfunction. METHODS: We analyzed 240 transplantation patients with preoperative renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m2). RESULTS: Compared with the non-dialytic conservative treatment group (n = 98), the intraoperative continuous renal replacement therapy group (n = 142) experienced more severe critical illness (as indicated by Model for End-Stage Liver Disease score) and more severe preoperative renal dysfunction, as well as more frequent hepatic encephalopathy, ventilatory care, and intensive care unit admission (P < .005). There were also worse outcomes regarding patient survival, graft survival, recovery of renal function, and postoperative complications. However, the intraoperative continuous renal replacement therapy group significantly escaped volume overload (adjusted odds ratio, 0.396; 95% confidence interval, 0.223-0.703; P = .002) and unnecessary changes in serum sodium concentration ≥10 mmol/L during surgery (adjusted odds ratio, 0.208; 95% confidence interval, 0.065-0.665; P = .008). CONCLUSIONS: Considering the more severe critical illness of the intraoperative continuous renal replacement therapy group but the low frequency of volume overload and serum sodium fluctuation, intraoperative continuous renal replacement therapy could be useful during liver transplantation in critically ill patients with renal dysfunction. Randomized, controlled studies that could demonstrate outcome benefits and indications of intraoperative continuous renal replacement therapy during liver transplantation are needed.


Assuntos
Cuidados Intraoperatórios/métodos , Hepatopatias/cirurgia , Transplante de Fígado/métodos , Insuficiência Renal/terapia , Terapia de Substituição Renal/métodos , Adulto , Idoso , Feminino , Taxa de Filtração Glomerular , Humanos , Rim/fisiopatologia , Hepatopatias/complicações , Hepatopatias/fisiopatologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Insuficiência Renal/etiologia , Insuficiência Renal/fisiopatologia , Estudos Retrospectivos , Resultado do Tratamento
7.
Br J Anaesth ; 118(6): 883-891, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28541533

RESUMO

BACKGROUND: : In our preliminary study, the modified Marsh (M-Marsh) model caused an inadvertent underdosing of propofol in underweight patients. However, the predictive performance of the M-Marsh and Schnider models incorporated in commercially available target-controlled infusion (TCI) pumps was not evaluated in underweight patients. METHODS: : Thirty underweight patients undergoing elective surgery were randomly allocated to receive propofol via TCI using the M-Marsh or Schnider models. The target effect-site concentrations (Ces) of propofol were, in order, 2.5, 3, 4, 5, 6 and 2 µg ml -1 . Arterial blood samples were obtained at least 7 min after achieving each pseudo-steady-state. RESULTS: A total of 172 plasma samples were used to determine the predictive performance of both models. The pooled median (95% confidence interval) biases and inaccuracies at a target Ce ≤ 3 µg ml -1 were -22.6 (-28.8 to -12.6) and 31.9 (24.8-36.8) for the M-Marsh model and 9.0 (1.7-16.4) and 28.5 (21.7-32.8) for the Schnider model, respectively. These values at Ce ≥ 4 µg ml -1 were -9.6 (-16.0 to -6.0) and 24.7 (21.1-27.9) for the M-Marsh model and 19.8 (12.9-25.7) and 36.2 (31.4-39.7) for the Schnider model, respectively. CONCLUSIONS: The pooled biases and inaccuracies of both models were clinically acceptable. However, the M-Marsh and Schnider models consistently produced negatively and positively biased predictions, respectively, in underweight patients. In particular, the M-Marsh model showed greater inaccuracy at target Ce ≤ 3 µg ml -1 and the Schnider model showed greater inaccuracy at target Ce ≥ 4 µg ml -1 . Therefore, it is necessary to develop a new pharmacokinetic model for propofol in underweight patients. CLINICAL TRIAL REGISTRATION: KCT0001502.


Assuntos
Anestesia Geral/métodos , Anestesia Intravenosa/métodos , Anestésicos Intravenosos/administração & dosagem , Propofol/administração & dosagem , Magreza/complicações , Adulto , Anestésicos Intravenosos/sangue , Simulação por Computador , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Valor Preditivo dos Testes , Propofol/sangue , Estudos Prospectivos , Reprodutibilidade dos Testes , Magreza/fisiopatologia
8.
J Biotechnol ; 257: 118-121, 2017 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-27989733

RESUMO

Phage display biopanning is a powerful in vitro selection process for screening and identifying peptides that bind to a target protein of interest. With the aim of replacing antibodies in immuno-diagnostic applications, we identified peptides whose binding characteristics mimicked those of anti-human myeloperoxidase (hMPO), a biomarker for acute cardiac diseases. Based on ELISA results from four phage clones, we selected and chemically synthesized a 12-mer peptide (SYIEPPERHRHR). Quartz crystal microbalance and surface plasmon resonance analyses revealed that the molar binding equilibrium ratio of the synthesized peptide was 0.023, approximately 43-fold lower than that of the anti-hMPO antibody. The dissociation constant (Kd) was 57nM, which was comparable to that of the native antibody (83nM). Next, we biotinylated the peptide at its N-terminus and attached the biotinylated peptide to the surface of streptavidin-coated magnetic particles to assess its ability to selectively capture hMPO. The binding equilibrium data were similar to the previous analyses; specifically, around 0.021mol peptide bound to 1mol of hMPO. Antigen capture was found to be selective and to be relatively little influenced by the presence of human serum albumin (HSA), an abundant constituent of serum. Our work demonstrates the potential of immunomagnetic isolation to achieve selective capture of a low-concentration antigen from complex solutions such as serum.


Assuntos
Anticorpos/química , Separação Imunomagnética/métodos , Biblioteca de Peptídeos , Peptídeos/química , Peptidomiméticos/química , Peroxidase/imunologia , Sequência de Aminoácidos , Afinidade de Anticorpos , Antígenos/imunologia , Antígenos/isolamento & purificação , Bacteriófagos , Humanos , Testes Imunológicos , Peptídeos/imunologia , Peptídeos/isolamento & purificação , Peroxidase/química , Ligação Proteica , Técnicas de Microbalança de Cristal de Quartzo , Albumina Sérica Humana/química , Ressonância de Plasmônio de Superfície
9.
Osteoporos Int ; 28(1): 231-237, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27509834

RESUMO

The study aims to evaluate the rate of transition to osteoporosis in 360 RA patients and estimate the rescreening intervals of bone mineral density (BMD) testing. Osteoporosis was newly developed in 24.8 % during mean follow-up of 7.4 years. The estimated time of a BMD testing interval was dependent on the baseline T-score in RA patients. INTRODUCTION: Although BMD testing is routinely performed in RA patients, the interval between BMD tests has not been determined. METHODS: We retrospectively recruited 360 consecutive female patients with RA, who underwent repeated BMD testing, with a mean age of 53.7 ± 10.2 years and a mean follow-up duration of 7.4 ± 5.0 years. We stratified the study participants into five groups based on their baseline T-score range. The testing interval was defined as the estimated time for 10 % of patients in each subgroup to transition to osteoporosis. Competing-risk analyses were performed with sensitivity analysis by menopausal status and risk factors for transition to osteoporosis. RESULTS: At baseline, 15 % of screened patients had osteoporosis, and during follow-up, that proportion increased to 24.8 %. The estimated BMD testing interval for 10 % of patients to develop osteoporosis was 9.6 years for those with normal BMD, 7.6 years for those with mild osteopenia, 4.7 years for those with moderate osteopenia, and 2.1 years for those with severe osteopenia. No significant risk factor for transition to osteoporosis was identified in this cohort. CONCLUSIONS: Our data indicate that osteoporosis will develop in less than 10 % of female RA patients during rescreening intervals of approximately 9 years for those with normal bone density at baseline, 7 years for those with mild osteopenia, 4 years for those with moderate osteopenia, and 2 years for those with severe osteopenia at baseline. BMD interval in RA patients could be adjusted according to their baseline BMD T-scores.


Assuntos
Artrite Reumatoide/complicações , Densidade Óssea/fisiologia , Osteoporose/diagnóstico , Osteoporose/etiologia , Absorciometria de Fóton , Adulto , Idoso , Artrite Reumatoide/fisiopatologia , Doenças Ósseas Metabólicas/diagnóstico , Doenças Ósseas Metabólicas/etiologia , Doenças Ósseas Metabólicas/fisiopatologia , Progressão da Doença , Feminino , Seguimentos , Humanos , Programas de Rastreamento/organização & administração , Pessoa de Meia-Idade , Osteoporose/fisiopatologia , Estudos Retrospectivos , Medição de Risco/métodos
10.
Colloids Surf B Biointerfaces ; 146: 585-9, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27424089

RESUMO

HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cell), a molecular complex of human α-lactalbumin and oleic acid, is known to have selective cytotoxic activity against certain types of tumors. This cytotoxicity is known to stem from water-insoluble oleic acid. In this study, we manufactured an alternative complex using liposome as an oleic acid delivery vesicle. We named this nanolipoplex LIMLET (LIposome Made LEthal to Tumor cell). The LIMLET vesicle contained approximately 90,200 oleic acid molecules inserted into its lipophilic phospholipid bilayer and had a nominal mean diameter of 127nm. Using a WST-1 assay, its cytotoxicity against two cancer cell lines, MDA-MB-231 (human breast cancer) and A549 (human lung cancer), were tested. The results were compared with that of a normal cell line, Vero (from monkey kidney). We found that (1) LIMLET showed distinctive cytotoxicity against A549 and MDA-MB-231 cells, whereas bare liposomes (containing no oleic acid) had no toxicity, even at high concentrations, and (2) LIMLET demonstrated selective, concentration-dependent toxicity against the cancer cells: the LD50 values of MDA-MB-231 and A549 cells were 1.3 and 2.2nM LIMLET, respectively, whereas the LD50 of Vero was 5.7nM. The strength of the tumoricidal effect appeared to stem from the number of oleic acid molecules present. Our result suggests that LIMLET, like HAMLET, is an interesting nanolipoplex that can potentially be developed into tumor treatments.


Assuntos
Lipossomos/química , Ácido Oleico/química , Células A549 , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Ácido Oleico/farmacologia
11.
J Chromatogr A ; 1457: 88-96, 2016 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-27363735

RESUMO

Exenatide is a synthetic version of the 39-mer peptide of Exendin-4, which is an FDA-approved therapeutic against Type II diabetes mellitus. However, exenatide has a very short in-serum half-life and PEGylation have been performed to improve its in-serum stability. PEGylation often yields multivalent binding to non-specific residues, and the desired species should be carefully separated by chromatographies. In this study, we first devised an aqueous-phase, two-step PEGylation process. This consists of thiolation of Lys 12 and 27 residues followed by attachment of PEG-maleimide (10kD) to thiol groups. This process yields various species: mono-PEGylates with positional isomers, di-PEGylate, and other higher MW substances. A prep-grade cationic exchange chromatography (HiTrap SP) at pH 3.0 partially separated mono- and di-PEGylates based on the molar ratio of conjugated PEG and peptide and thus molecular weight of the conjugates. To further investigate the chromatographic separation of positional isomers of mono-PEGylates, we prepared two kinds of exenatide analogs by point mutation; K12C and K27C. Each analog was mono-PEGylated with very high yield (>95%). When a mixture of the two positional isomers of mono-PEGylates was applied to HiTrap SP chromatography, K12C-PEGylate and K27C-PEGylate eluted separately at 0.22M and 0.33M NaCl, respectively. When the proportions of acid and its conjugate base of the amino acid residues adjacent to the PEGylation site at pH 3.0 were analyzed, K27C-PEGylate shows stronger positive charge than K12C-PEGylate, and we propose the residence time difference between the two mono-PEGylates could be due to the charge difference. ELISA result shows that the immuno-binding activity of both analogs and their mono-PEGylates are well maintained. Furthermore, both mono-PEGylates of the analogs show higher than 50-fold improved anti-trypsin stability. We expect that mono-PEGylates of the exenatide analogs are alternatives to the conventional C40-PEG.


Assuntos
Hipoglicemiantes/isolamento & purificação , Peptídeos/isolamento & purificação , Polietilenoglicóis/química , Peçonhas/isolamento & purificação , Cromatografia por Troca Iônica/métodos , Exenatida , Hipoglicemiantes/química , Isomerismo , Peso Molecular , Peptídeos/química , Peçonhas/química
12.
J Mol Recognit ; 29(9): 446-51, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27060481

RESUMO

A fluorescent reporter, 8-anilino-1-naphthalene sulfonic acid (ANS), can serve as a reference molecule for conformational transition of a protein because its aromatic carbons have strong affinity with hydrophobic cores of partially unfolded molten globules. Using a typical calcium-binding protein, bovine α-lactalbumin (BLA), as a model protein, we compared the ANS binding thermodynamics to the decalcified (10 mM EDTA treated) apo-BLA at two representative temperatures: 20 and 40 °C. This is because the authentic molten globule is known to form more heavily at an elevated temperature such as 40 °C. Isothermal titration calorimetry experiments revealed that the BLA-ANS interactions at both temperatures were entropy-driven, and the dissociation constants were similar on the order of 10(-4) M, but there was a dramatic changeover in the binding thermodynamics from endothermic at 20 °C to exothermic at 40 °C. We believe that the higher subpopulation of authentic molten globules at 40 °C than 20 °C would be responsible for the results, which also indicate that weak binding is sufficient to alter the ANS binding mechanisms. We expect that the thermodynamic properties obtained from this study would serve as a useful reference for investigating the binding of other hydrophobic ligands such as oleic acid to apo-BLA, because oleic acid is known to have tumor-selective cytotoxicity when complexed with partially unfolded α-lactalbumin. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Naftalenossulfonato de Anilina/metabolismo , Temperatura Alta , Lactalbumina/metabolismo , Termodinâmica , Calorimetria , Concentração de Íons de Hidrogênio , Ácido Oleico/metabolismo , Ligação Proteica , Dobramento de Proteína
13.
Ann Oncol ; 27(4): 608-18, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26712901

RESUMO

BACKGROUND: Guidelines recommend primary prophylaxis (PP) with granulocyte-colony-stimulating factors (G-CSF) for patients above a febrile neutropenia (FN) risk threshold of 20%. Practitioners often use FN rates of regimens based on data from randomized, controlled trials (RCTs), which are often comprised of highly selected patients. Patients in the community setting may be at higher risk of FN. MATERIALS AND METHODS: A systematic literature search was conducted for full-length articles reporting FN rates for breast cancer-related chemotherapies between January 1996 and February 2014. A regimen was included if there was at least one RCT and one observational study. Meta-regression was used to model the odds of FN. RESULTS: 130 studies involving 29 regimens and 50 069 patients were identified. Sixty-five observational study (n = 7812) and 110 RCT (n = 42 257) cohorts were included. The unadjusted FN rate was 11.7% in observational and 7.9% in RCT cohorts. The univariable odds ratio (OR) for FN in the observational study compared with RCT cohorts was 1.58 [95% confidence interval (CI) 1.09-2.28; P = 0.017]. The FN rates remained significantly higher in the observational study compared with RCT cohorts (OR = 1.74; 95% CI 1.15-2.62; P = 0.012) after adjusting for age, chemotherapy intent, and regimen; this meant that a 13% (95% CI 8.7% to 17.9%) FN rate in RCT would translate into 20% FN rate in observational study. CONCLUSIONS: FN rates in the observational studies are significantly higher than suggested by RCTs. Guidelines should clarify how FN rates from RCTs should be applied in clinical practice. Large population-based studies are needed to confirm FN rates in the real world.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neutropenia Febril/epidemiologia , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Neoplasias da Mama/patologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Neutropenia Febril/induzido quimicamente , Neutropenia Febril/patologia , Feminino , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
Neurotoxicology ; 52: 188-97, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26687398

RESUMO

Accumulating evidence indicates that chronic low dose exposure to Bisphenol A (BPA), an endocrine disruptor, may disrupt normal brain development and behavior mediated by the gonadotropin-releasing hormone (GnRH) pathways. While it is known that GnRH neurons in the hypothalamus regulate reproductive physiology and behavior, functional roles of extra-hypothalamic GnRH neurons remain unclear. Furthermore, little is known whether BPA interacts with extra-hypothalamic GnRH3 neural systems in vulnerable developing brains. Here we examined the impact of low dose BPA exposure on the developing GnRH3 neural system, eye and brain growth, and locomotor activity in transgenic medaka embryos and larvae with GnRH3 neurons tagged with GFP. Fertilized eggs were collected daily and embryos/larvae were chronically exposed to 200ng/ml of BPA, starting at 1 day post fertilization (dpf). BPA significantly increased fluorescence intensity of the GnRH3-GFP neural population in the terminal nerve (TN) of the forebrain at 3dpf, but decreased the intensity at 5dpf, compared with controls. BPA advanced eye pigmentation without affecting eye and brain size development, and accelerated times to hatch. Following chronic BPA exposure, 20dpf larvae showed suppression of locomotion, both in distance covered and speed of movement (47% and 43% reduction, respectively). BPA-induced hypoactivity was accompanied by decreased cell body sizes of individual TN-GnRH3 neurons (14% smaller than those of controls), but not of non-GnRH3 neurons. These novel data demonstrate complex neurobehavioral effects of BPA on the development of extra-hypothalamic GnRH3 neurons in teleost fish.


Assuntos
Compostos Benzidrílicos/administração & dosagem , Compostos Benzidrílicos/toxicidade , Hormônio Liberador de Gonadotropina/metabolismo , Locomoção/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Oryzias/fisiologia , Fenóis/administração & dosagem , Fenóis/toxicidade , Animais , Animais Geneticamente Modificados , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Tamanho Celular/efeitos dos fármacos , Olho/efeitos dos fármacos , Olho/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Larva/fisiologia , Neurônios/citologia , Neurônios/metabolismo , Oryzias/embriologia , Taxa de Sobrevida
15.
Cell Death Differ ; 23(3): 484-95, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26337669

RESUMO

p130Cas regulates cancer progression by driving tyrosine receptor kinase signaling. Tight regulation of p130Cas expression is necessary for survival, apoptosis, and maintenance of cell motility in various cell types. Several studies revealed that transcriptional and post-translational control of p130Cas are important for maintenance of its expression and activity. To explore novel regulatory mechanisms of p130Cas expression, we studied the effect of microRNAs (miRs) on p130Cas expression in human breast cancer MCF7 cells. Here, we provide experimental evidence that miR-362-3p and miR-329 perform a tumor-suppressive function and their expression is downregulated in human breast cancer. miR-362-3p and miR-329 inhibited cellular proliferation, migration, and invasion, thereby suppressing tumor growth, by downregulating p130Cas. Ectopic expression of p130Cas attenuated the inhibitory effects of the two miRs on tumor progression. Relative expression levels of miR-362-3p/329 and p130Cas between normal and breast cancer correlated inversely; miR-362-3p/329 expression was decreased, whereas that of p130Cas increased in breast cancers. Furthermore, we showed that downregulation of miR-362-3p and miR-329 was caused by differential DNA methylation of miR genes. Enhanced DNA methylation (according to methylation-specific PCR) was responsible for downregulation of miR-362-3p and miR-329 in breast cancer. Taken together, these findings point to a novel role for miR-362-3p and miR-329 as tumor suppressors; the miR-362-3p/miR-329-p130Cas axis seemingly has a crucial role in breast cancer progression. Thus, modulation of miR-362-3p/miR-329 may be a novel therapeutic strategy against breast cancer.


Assuntos
Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Animais , Sequência de Bases , Sítios de Ligação , Neoplasias da Mama/patologia , Proteína Substrato Associada a Crk/genética , Proteína Substrato Associada a Crk/metabolismo , Progressão da Doença , Regulação para Baixo , Feminino , Expressão Gênica , Humanos , Células MCF-7 , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/metabolismo , Dados de Sequência Molecular , Transplante de Neoplasias , Interferência de RNA
16.
Colloids Surf B Biointerfaces ; 136: 786-90, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26529386

RESUMO

Liposome is one of the frequently used carriers for active targeting systems in vivo. Such parameters as its size, surface charge, and surface modifiers are known to influence the liposome uptake by macrophage cells. In this study, we investigated the effects of liposome size and polyethylene glycol (PEG) surface modifier on the liposomal internalization to murine macrophage (RAW-264.7), by using an imaging analysis technique. Three different sized liposomes (100, 200, and 400 nm in nominal diameter) labeled with rhodamine fluorescence were used. Liposome internalization appeared to reach a pseudo-steady plateau in about 5h incubation, and most of the internalized liposomes were seen to accumulate in the cytosol including cellular extensions. The maximum fluorescent density from the internalized liposomes was similar between 100 nm and 200 nm liposomes. However, that of the larger 400 nm liposome was approximately 1.7 times higher than the others, confirming the previous report that the larger the liposomes are the higher the degree of internalization is. When the outside of the 200 nm liposomes was modified with biocompatible anchor molecule (BAM) consisting of PEG (ca. 2kD molecular weight) moiety, the endocytosis was indeed reduced by about 2.1-fold, despite the increase of the hydrodynamic size due to BAM conjugation. This fluorescence-based cellular imaging analysis can be used to quantitatively monitor and optimize cellular internalization systems.


Assuntos
Endocitose , Lipossomos , Macrófagos/metabolismo , Polietilenoglicóis/química , Animais , Linhagem Celular , Camundongos , Propriedades de Superfície
17.
Bone Marrow Transplant ; 50(4): 523-30, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25581410

RESUMO

Trial outcomes comparing cytokine agents for PBSC mobilization in autologous hematopoietic transplant patients have been controversial. We performed a systematic review and meta-analysis of evidence available on pegfilgrastim vs filgrastim in chemo-cytokine mobilization. Electronic literature searches of PubMed, EMBASE and CENTRAL identified nine articles eligible for qualitative analysis with one randomized controlled trial. Eight articles involving 719 patients were included in the meta-analysis. Results showed similar CD34+ cell collection yields for pegfilgrastim and filgrastim (SDM -0.08, 95% CI: -0.388 to 0.228). On comparison with filgrastim, pegfilgrastim showed a significantly earlier apheresis onset time (SDM: -0.512, 95% CI: -0.973 to -0.050) and reduction in required apheresis procedures (SDM -0.260, 95% CI: -0.466 to -0.054). Times to leukocyte (⩾1.0 × 10(9)/L) and platelet (⩾20 × 10(9)/L) recovery were similar between groups (SDM: 0.015, 95% CI: -0.41 to 0.44 and SDM: 0.309, 95% CI: -0.11 to 0.72, respectively). Both agents were well tolerated and mild bone pain was the most frequently reported adverse event. Pegfilgrastim may be a convenient alternative to filgrastim in PBSC mobilization for multiple myeloma and lymphoma patients, but further studies are required to clarify effects of cytokine dosage and previous cytotoxic exposure in specific subpopulations.


Assuntos
Filgrastim/uso terapêutico , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Fármacos Hematológicos/uso terapêutico , Mobilização de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas , Transplante de Células-Tronco de Sangue Periférico , Feminino , Humanos , Masculino , Polietilenoglicóis , Proteínas Recombinantes/uso terapêutico
18.
Aliment Pharmacol Ther ; 39(8): 854-63, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24612291

RESUMO

BACKGROUND: Metformin use has been associated with a decreased incidence and mortality of various cancers. AIM: To evaluate the association between metformin use and gastric cancer. METHODS: We randomly selected 100 000 type 2 diabetic patients from the 2004 Korean National Health Insurance claim database, and assessed gastric cancer incidence among 39 989 patients (aged 30-97 years) who were regularly treated with anti-diabetic drugs and followed-up from 2004 to 2010. In total, 26 690 patients had used metformin out of 32 978 diabetics who had not regularly used insulin (insulin non-users), and 5855 patients had used metformin out of 7011 regular insulin users. RESULTS: Patients who used metformin showed a lower incidence of gastric cancer than those who did not use metformin, in insulin non-users (P = 0.047, log-rank test). However, in patients on regular insulin, there was no difference of gastric cancer incidence according to metformin use. In insulin non-users, the adjusted hazard ratio (AHR) for metformin use was 0.73 (95% confidential interval [CI], 0.53-1.01) with borderline statistical significance (P = 0.059). Duration of metformin use was associated with the reduction in gastric cancer risk (AHR, 0.88; 95% CI 0.81-0.96, P = 0.003), especially in patients who used metformin for more than 3 years (AHR, 0.57; 95% CI, 0.37-0.87; P = 0.009). CONCLUSION: Metformin use >3 years in type 2 diabetics who do not use insulin is associated with a significantly reduced gastric cancer risk.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Neoplasias Gástricas/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Bases de Dados Factuais , Feminino , Seguimentos , Humanos , Hipoglicemiantes/administração & dosagem , Incidência , Insulina/uso terapêutico , Masculino , Metformina/administração & dosagem , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Risco , Neoplasias Gástricas/epidemiologia , Fatores de Tempo
19.
Oncogene ; 33(16): 2011-8, 2014 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-23624913

RESUMO

Substrate-specific degradation is a key feature of the ubiquitin proteasome system. Substrate specificity is typically directed by the E3 or ubiquitin ligase; such specificity can be conferred either by ligase modification or expression or conversely via modification of substrates that permit their recognition by a specific E3 ligase. The most well-known example of such complexes are the Cullin-RING ligases (CRLs). CRLs are composed of one of seven cullin-family scaffold proteins; the CRL serves as a scaffold that interacts directly with a RING-domain enzyme (Rbx1/2) through an extensive protein-protein interface within the globular C-terminal domain. At the N terminus, the cullin associates with an adaptor protein through cullin-repeat motifs. This adaptor, in turn, facilitates recruitment of a substrate-specifying factor that recruits the target to be ubiquitylated. The prototypical CRL is the cul1-containing complex, commonly referred to as the Skp1-Cul1-Fbox (SCF) ligase. SCF ligases contribute to the timely destruction of numerous substrates thereby ensuring normal cell growth. The importance of SCF function is highlighted by cancer-specific alterations in either the expression or the function of select F-box substrate-specific adaptors that results in neoplastic conversion. Herein, we discuss the current understanding of SCF function and contribution to cell biology.


Assuntos
Proteínas Culina/metabolismo , Proteínas Quinases Associadas a Fase S/metabolismo , Proteínas Ligases SKP Culina F-Box/metabolismo , Proteínas Contendo Repetições de beta-Transducina/metabolismo , Humanos , Modelos Biológicos , Proteína NEDD8 , Especificidade por Substrato , Ubiquitinas/metabolismo
20.
Oncogene ; 33(1): 129-33, 2014 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-23318439

RESUMO

Cyclin D1 deregulation is implicated in the genesis of multiple human cancers. Importantly, nuclear cyclin D1 retention during S-phase promotes DNA re-replication and subsequent genomic instability, providing a direct correlation between aberrant cyclin D1/CDK4 activity, transcriptional regulation and double strand DNA break (DSB) induction. Together, these molecular events catalyze the genomic instability necessary for neoplastic transformation. Given that replication-associated DNA damage is central to cyclin D1-driven neoplasia, inactivation of critical checkpoint mediators should augment cyclin D1-dependent tumorigenesis in vivo. To interrogate potential synergy between constitutively nuclear cyclin D1 expression and impaired DSB-induced checkpoint integrity, Ataxia Telangiectasia Mutated (ATM)-deficient mice harboring the Eµ-D1T286A transgene were generated and evaluated for tumor onset. Eµ-D1T286A/ATM-/- mice exhibit dramatically accelerated incidence of both B- and T-cell lymphomas relative to Eµ-D1T286A or ATM-/- control cohorts. Lymphomas exhibit clonal chromosomal alterations distinct from ATM-/- mice, which typically acquire translocations involving the Tcrα/δ locus during V(D)J recombination, and instead harbor alterations at the c-Myc locus. Collectively, these findings reveal an intricate relationship wherein nuclear cyclin D1/CDK4 drives genomic instability in the absence of ATM function and clonal selection of cells harboring alterations within the murine c-Myc locus, ultimately facilitating transformation and tumor formation.


Assuntos
Carcinogênese/genética , Ciclina D1/metabolismo , Instabilidade Genômica , Linfoma/genética , Animais , Proteínas Mutadas de Ataxia Telangiectasia/deficiência , Proteínas Mutadas de Ataxia Telangiectasia/genética , Carcinogênese/metabolismo , Núcleo Celular/metabolismo , Aberrações Cromossômicas , Humanos , Linfoma/metabolismo , Camundongos , Camundongos Knockout , Transporte Proteico , Proteínas Proto-Oncogênicas c-myc/metabolismo , Carga Tumoral
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