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1.
Invest New Drugs ; 42(2): 207-220, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38427117

RESUMO

It has previously been demonstrated that the polybisphosphonate osteodex (ODX) inhibits bone resorption in organ-cultured mouse calvarial bone. In this study, we further investigate the effects by ODX on osteoclast differentiation, formation, and function in several different bone organ and cell cultures. Zoledronic acid (ZOL) was used for comparison. In retinoid-stimulated mouse calvarial organ cultures, ODX and ZOL significantly reduced the numbers of periosteal osteoclasts without affecting Tnfsf11 or Tnfrsf11b mRNA expression. ODX and ZOL also drastically reduced the numbers of osteoclasts in cell cultures isolated from the calvarial bone and in vitamin D3-stimulated mouse crude bone marrow cell cultures. These data suggest that ODX can inhibit osteoclast formation by inhibiting the differentiation of osteoclast progenitor cells or by directly targeting mature osteoclasts. We therefore assessed if osteoclast formation in purified bone marrow macrophage cultures stimulated by RANKL was inhibited by ODX and ZOL and found that the initial formation of mature osteoclasts was not affected, but that the bisphosphonates enhanced cell death of mature osteoclasts. In agreement with these findings, ODX and ZOL did not affect the mRNA expression of the osteoclastic genes Acp5 and Ctsk and the osteoclastogenic transcription factor Nfatc1. When bone marrow macrophages were incubated on bone slices, ODX and ZOL inhibited RANKL-stimulated bone resorption. In conclusion, ODX does not inhibit osteoclast formation but inhibits osteoclastic bone resorption by decreasing osteoclast numbers through enhanced cell death of mature osteoclasts.


Assuntos
Reabsorção Óssea , Osteoclastos , Animais , Camundongos , Osteoclastos/metabolismo , Osteogênese , Medula Óssea , Células Cultivadas , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/metabolismo , Macrófagos/metabolismo , Diferenciação Celular , Morte Celular , Ácido Zoledrônico/farmacologia , Ácido Zoledrônico/metabolismo , RNA Mensageiro/metabolismo , Ligante RANK/farmacologia , Ligante RANK/metabolismo
2.
Invest New Drugs ; 41(5): 688-698, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37556022

RESUMO

Medulloblastoma (MB) is the most common pediatric brain tumor. The therapy frequently causes serious side effects, and new selective therapies are needed. MB expresses hyper sialylation, a possible target for selective therapy. The cytotoxic efficacy of a poly guanidine conjugate (GuaDex) incubated with medulloblastoma cell cultures (DAOY and MB-LU-181) was investigated. The cells were incubated with 0.05-8 µM GuaDex from 15 min to 72 h. A fluorometric cytotoxicity assay (FMCA) measured the cytotoxicity. Labeled GuaDex was used to study tumor cell interaction. FITC-label Sambucus nigra confirmed high expression of sialic acid (Sia). Immunofluorescence microscopy was used to visualize the cell F-actin and microtubules. The cell interactions were studied by confocal and fluorescence microscopy. Annexin-V assay was used to detect apoptosis. Cell cycle analysis was done by DNA content determination. A wound-healing migration assay determined the effects on the migratory ability of DAOY cells after GuaDex treatment. IC50 for GuaDex was 223.4 -281.1 nM. FMCA showed potent growth inhibition on DAOY and MB-LU-181 cells at 5 uM GuaDex after 4 h of incubation. GuaDex treatment induced G2/M phase cell cycle arrest. S. nigra FITC-label lectin confirmed high expression of Sia on DAOY medulloblastoma cells. The GuaDex treatment polymerized the cytoskeleton (actin filaments and microtubules) and bound to DNA, inducing condensation. The Annexin V assay results were negative. Cell migration was inhibited at 0.5 µM GuaDex concentration after 24 h of incubation. GuaDex showed potent cytotoxicity and invasion-inhibitory effects on medulloblastoma cells at low micromolar concentrations. GuaDex efficacy was significant and warrants further studies.


Assuntos
Neoplasias Cerebelares , Meduloblastoma , Criança , Humanos , Meduloblastoma/tratamento farmacológico , Meduloblastoma/genética , Meduloblastoma/metabolismo , Guanidina/farmacologia , Guanidina/uso terapêutico , Fluoresceína-5-Isotiocianato/farmacologia , Fluoresceína-5-Isotiocianato/uso terapêutico , Proliferação de Células , Linhagem Celular Tumoral , Apoptose , Neoplasias Cerebelares/tratamento farmacológico , Neoplasias Cerebelares/metabolismo , Neoplasias Cerebelares/patologia , DNA
3.
Invest New Drugs ; 40(3): 565-575, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35312943

RESUMO

Glioblastoma multiforme (GBM) is a malignant CNS tumor with a poor prognosis. GBM shows aberrant glycosylation with hypersialylation. This property is a potential target for therapy. This study investigates the growth inhibitory efficacy of poly-guanidine (GuaDex), with an affinity for sialic acid (Sia). Glioma cell cultures and patient-derived glioma cell lines (PDGCLs) expressing Prominin-1 (CD133) were used. Human fibroblasts and astrocyte-derived cells were used as controls. Temozolomide (standard GBM drug, TMZ) and DMSO were used as a comparison. GuaDex at 1-10 µM concentrations, were incubated for 3.5-72 h and with PDGCLs cells for 6-24 h. The cytotoxicity was estimated with a fluorometric cytotoxicity assay (FMCA). Fluorescence-labelled GuaDex was used to study the cell interactions. Sia expression was confirmed with a fluorescence labelled Sia binding lectin. Expression of glial fibrillary acidic protein was determined. GuaDex induction of growth inhibition was fast, showing after less than 5 min incubation while the control cells were not affected even after 50 min incubation. The growth inhibitory effect on PDGCLs spheroids was persistent still showing after 4 weeks post-treatment. The growth inhibition of GuaDex was induced at low µM concentrations while TMZ induced only a slight inhibition at mM concentrations. GuaDex efficacy appears significant and warrants further studies.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Neoplasias Encefálicas/patologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/tratamento farmacológico , Glioma/metabolismo , Guanidina/farmacologia , Guanidina/uso terapêutico , Humanos , Células-Tronco Neoplásicas , Temozolomida/farmacologia , Temozolomida/uso terapêutico
4.
Nucleic Acids Res ; 43(7): e49, 2015 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-25618848

RESUMO

We describe solid-phase cloning (SPC) for high-throughput assembly of expression plasmids. Our method allows PCR products to be put directly into a liquid handler for capture and purification using paramagnetic streptavidin beads and conversion into constructs by subsequent cloning reactions. We present a robust automated protocol for restriction enzyme based SPC and its performance for the cloning of >60 000 unique human gene fragments into expression vectors. In addition, we report on SPC-based single-strand assembly for applications where exact control of the sequence between fragments is needed or where multiple inserts are to be assembled. In this approach, the solid support allows for head-to-tail assembly of DNA fragments based on hybridization and polymerase fill-in. The usefulness of head-to-tail SPC was demonstrated by assembly of >150 constructs with up to four DNA parts at an average success rate above 80%. We report on several applications for SPC and we suggest it to be particularly suitable for high-throughput efforts using laboratory workstations.


Assuntos
Clonagem Molecular/métodos , DNA/genética , Enzimas de Restrição do DNA/metabolismo , Vetores Genéticos , Hibridização de Ácido Nucleico
5.
Opt Express ; 22(25): 30756-68, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25607024

RESUMO

In water-window soft x-ray microscopy the studied object is typically larger than the depth of focus and the sample illumination is often partially coherent. This blurs out-of-focus features and may introduce considerable fringing. Understanding the influence of these phenomena on the image formation is therefore important when interpreting experimental data. Here we present a wave-propagation model operating in 3D for simulating the image formation of thick objects in partially coherent soft x-ray microscopes. The model is compared with present simulation methods as well as with experiments. The results show that our model predicts the image formation of transmission soft x-ray microscopes more accurately than previous models.

6.
Opt Express ; 21(7): 8051-61, 2013 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-23571895

RESUMO

Focusing hard x-ray free-electron laser radiation with extremely high fluence sets stringent demands on the x-ray optics. Any material placed in an intense x-ray beam is at risk of being damaged. Therefore, it is crucial to find the damage thresholds for focusing optics. In this paper we report experimental results of exposing tungsten and diamond diffractive optics to a prefocused 8.2 keV free-electron laser beam in order to find damage threshold fluence levels. Tungsten nanostructures were damaged at fluence levels above 500 mJ/cm(2). The damage was of mechanical character, caused by thermal stress variations. Diamond nanostructures were affected at a fluence of 59 000 mJ/cm(2). For fluence levels above this, a significant graphitization process was initiated. Scanning Electron Microscopy (SEM) and µ-Raman analysis were used to analyze exposed nanostructures.


Assuntos
Diamante/química , Diamante/efeitos da radiação , Lasers , Lentes , Refratometria/instrumentação , Tungstênio/química , Tungstênio/efeitos da radiação , Desenho de Equipamento , Análise de Falha de Equipamento , Doses de Radiação , Raios X
7.
Eur J Cancer ; 181: 198-207, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36682096

RESUMO

AIMS: This study aimed to assess the efficacy and safety of ODX, a novel, cytotoxic, bone-targeting drug candidate, in castration-resistant prostate cancer bone metastatic disease. METHODS: Patients with progressive disease were randomised to ten cycles of ODX, intravenous infusion Q2W (3, 6, and 9 mg/kg, respectively). The primary objective was to assess the relative change from baseline in bone alkaline phosphatase (B-ALP) and serum-aminoterminal-propeptide of Type I procollagen (S-P1NP) at 12 weeks. The inclusion criteria selected were broad, and a double-blind design was used to ensure objective recruitment of patients for the assessment of efficacy. None of the patients received bone-protecting agents during the ODX treatment period. RESULTS: Fifty-five 21,20 and 14) patients were randomised to ODX (3, 6 and 9 mg/kg), respectively. The lower number of patients in arm 3 was due to too low a recruitment rate towards the end of the study. The median treatment time were 14, 13 and 14 weeks, respectively. The decrease in B-ALP at 12 weeks in study arms 3, 6 and 9 mg/kg was seen in 6/15 (40%), 8/12 (67%) and 5/12 (42%) patients, respectively, whereas the corresponding numbers for P1NP were 8/15 (53%), 8/12 (67%), and 4/12 (33%), respectively. The median decrease in B-ALP and P1NP at 12 weeks for study arms 3, 6 and 9 mg/kg were 37%, 14% and 43%, respectively, and 51%, 40% and 64%, respectively. The decrease in serum C-terminal telopeptide at 12 weeks was seen in the vast majority of patients and in about one-third of patients in bone scan index. ODX was well tolerated, and no drug-related serious adverse events occurred. There were no significant differences between study arms regarding efficacy and safety. CONCLUSIONS: ODX was well tolerated and demonstrated inhibitory effects on markers related to the vicious cycle in bone at all three doses. The reduction in metastatic burden, assessed with bone scan index, supports this finding. Studies with continued ODX treatment until disease progression are being planned (ClinicalTrials.gov Identifier: NCT02825628).


Assuntos
Antineoplásicos , Neoplasias Ósseas , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/patologia , Antineoplásicos/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Progressão da Doença , Método Duplo-Cego
8.
Opt Lett ; 37(24): 5046-8, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23258000

RESUMO

We demonstrate the use of the classical Ronchi test to characterize aberrations in focusing optics at a hard x-ray free-electron laser. A grating is placed close to the focus and the interference between the different orders after the grating is observed in the far field. Any aberrations in the beam or the optics will distort the interference fringes. The method is simple to implement and can provide single-shot information about the focusing quality. We used the Ronchi test to measure the aberrations in a nanofocusing Fresnel zone plate at the Linac Coherent Light Source at 8.194 keV.


Assuntos
Algoritmos , Análise de Falha de Equipamento/instrumentação , Lasers , Lentes , Nanotecnologia/instrumentação , Refratometria/instrumentação , Elétrons , Análise de Falha de Equipamento/métodos , Luz , Nanotecnologia/métodos , Refratometria/métodos , Espalhamento de Radiação , Raios X
9.
Opt Lett ; 36(14): 2728-30, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21765523

RESUMO

Soft-x-ray cryotomography allows quantitative and high-resolution three-dimensional imaging of intact unstained cells. To date, the method relies on synchrotron-radiation sources, which limits accessibility for researchers. Here we present a laboratory water-window microscope for cryotomography. It is based on a λ=2.48 nm liquid-jet laser-plasma source, a normal-incidence multilayer condenser, a 30 nm zone-plate objective, and a cryotilt sample holder. We demonstrate high-resolution imaging, as well as quantitative tomographic imaging, of frozen intact cells. The reconstructed tomogram of the intracellular local absorption coefficient shows details down to ∼100 nm.


Assuntos
Laboratórios , Microscopia/métodos , Tomografia/métodos , Linfócitos B/citologia , Células HEK293 , Humanos , Rim/citologia , Saccharomyces cerevisiae/citologia , Raios X
10.
Rapid Commun Mass Spectrom ; 25(17): 2453-8, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21818805

RESUMO

Data on the use of accelerator mass spectrometry (AMS) in conjunction with in vivo studies of macromolecular drugs are scarce. The present study shows the versatility of this technique when investigating the pharmacokinetics (PK) of a macromolecular drug candidate, a polybisphosphonate conjugate (ODX). The aforementioned is a polymer (molecular weight ~30 kDa) constituting a carbohydrate backbone with covalently linked ligands (aldendronate and aminoguanidine) and is intended for treatment of osteoporosis and the therapy of bone metastasis from prostate cancer. The conjugate is prepared through partial oxidation of the carbohydrate and sequential coupling of the ligands by reductive amination. (14)C was incorporated in the conjugate by means of coupling a commercially available (14)C-lysine in the conjugation sequence. Fifteen rats were injected intravenously with (14)C-labelled ODX (150 µg, 14 Bq/rat) and blood samples were collected at 1, 2, 4, 6, and 24 h post-injection (3 rats/time point). Liver, spleen and kidney samples were collected at 4 and 24 h post-injection. Blood from each time point (triplicate) were collected for AMS measurement determining the isotopic ratio ((14)C/(12)C) and consequently the drug concentration in blood. ODX showed a transient presence in blood circulation; 93% of the total dose was cleared from the circulation within 1 h. The half-life after 1 h was estimated to be about 3 h; 0.7% of the administered (14)C dose of ODX remained in circulation after 24 h. The major (14)C accumulation was in the liver, the spleen and the kidneys indicating the probable route of metabolism and excretion. This study demonstrates the versatility of AMS for pharmacological in vivo studies of macromolecules. Labelling with (14)C is relatively simple, inexpensive and the method requires minimal radioactivity, eliminating the need for radioprotection precautions in contrast to methods using scintillation counting.


Assuntos
Difosfonatos/farmacocinética , Avaliação Pré-Clínica de Medicamentos/métodos , Substâncias Macromoleculares/farmacocinética , Espectrometria de Massas/métodos , Polímeros/farmacocinética , Alendronato/química , Animais , Isótopos de Carbono/química , Difosfonatos/administração & dosagem , Difosfonatos/química , Guanidinas/química , Substâncias Macromoleculares/administração & dosagem , Substâncias Macromoleculares/química , Masculino , Polímeros/administração & dosagem , Polímeros/química , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
11.
BJU Int ; 105(2): 225-8, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19624593

RESUMO

OBJECTIVE: To evaluate the effect of an extract of Butea superba (Roxb.) (BS) compared to sildenafil for treating erectile dysfunction (ED). PATIENTS AND METHODS: An open label study was carried out among 32 men with organic ED to evaluate the response on the International Index of Erectile Function 5 (IIEF-5) to BS, a 'natural health' product (100 mg), compared to 50 mg of sildenafil (a phosphodiesterase-5 inhibitor). After a 1-week wash-out, responders to BS received either 100 mg starch or 100 mg of another batch of BS (double-blind). RESULTS: Of the patients in the BS group, 27 (84%) responded positively, compared with 26 (81%) in the sildenafil group. When assessing the score alone, 12 (38%) had a better score after taking BS, compared to seven (22%) after sildenafil, and eight (25%) had the same score. The results were surprising and could not be repeated in the double-blind part of the study, where no effect of BS was recorded. CONCLUSIONS: A 'natural' health product containing BS was more effective than sildenafil in the first part of the study, but in the second, using another batch of BS, the positive result could not be repeated and no effect was recorded. The conclusion is that the first preparation of BS was most likely blended with a phosphodiesterase-5 inhibitor, later confirmed by the supplier of BS (a natural health products company) after their own analysis.


Assuntos
Butea , Impotência Vasculogênica/tratamento farmacológico , Inibidores de Fosfodiesterase/uso terapêutico , Fitoterapia , Piperazinas/uso terapêutico , Extratos Vegetais/uso terapêutico , Sulfonas/uso terapêutico , Adulto , Idoso , Estudos de Casos e Controles , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Ereção Peniana/efeitos dos fármacos , Purinas/uso terapêutico , Citrato de Sildenafila , Resultado do Tratamento
12.
Opt Express ; 17(13): 11057-65, 2009 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-19550505

RESUMO

Computed tomography based on high-resolution soft x-ray microscopy utilizes the natural contrast for biological specimens provided by the water window (lambda = 2.4 - 4.4 nm) and the high resolving power of zone plate objectives. It is capable of revealing the 3D structure of biological specimens at sub-visible-microscopic resolution. To date, the technique has only been available at synchrotron-based microscopes, which limits the researchers access. In the present paper we demonstrate high-resolution soft x-ray tomography with a laboratory zone-plate-based soft x-ray microscope. The specimen, a diatom mounted on a glass capillary, was reconstructed from a tilt series of 53 images covering 180 degrees using a filtered back projection algorithm. The resolution of the tomogram was estimated to a half period of 140 nm using a differential-phase-residual method. Cryo-fixation, increased source brightness and extended-depth-of-focus objectives are important for pushing the resolution of compact systems for biological samples.


Assuntos
Microscopia/métodos , Óptica e Fotônica , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Microscopia Crioeletrônica/métodos , Diatomáceas , Desenho de Equipamento , Processamento de Imagem Assistida por Computador , Dispositivos Ópticos , Fótons , Dióxido de Silício/química , Síncrotrons , Raios X
13.
Int J Oncol ; 35(2): 281-5, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19578741

RESUMO

Guanidine compounds have important biochemical properties. Aminoguanidine, as an example, is an anti-oxidant, a nitric oxide synthase inhibitor (NOS) which prevents nitric oxide formation, and an inhibitor of advanced glycosylation end products (AGEs). As an anti-oxidant, aminoguanidine may affect the formation of atherosclerotic lesions through protection from LDL oxidation. Inhibition of AGEs could have a preventive effect on the tissue damage caused by diabetes where AGEs are considered to be an important factor. The role of NO in cancer is complex and not fully understood, but it may have influence on growth and progression. In this study, the tumor growth inhibitory effect of conjugated guanidine (i.e. a polyguanidine) was investigated. The effect on tumor cell growth was studied in cultures of prostate, breast, bladder and renal cell cancer, and a fluorometric cytotoxicity assay was performed. Guanidine conjugates were prepared by reacting aminoguanidine or agmatine with periodate oxidized dextran followed by reductive amination. The cytotoxic effect was compared with an anthracycline (adriamycin). The dextran-guanidine conjugates were cytotoxic at low micromolar concentrations, and the dextran-aminoguanidine conjugate (GDC) had the highest efficacy, being more efficient than adriamycin, in all of the tested tumor cell lines. Breast and prostate cancer cells were the most sensitive. At 0.5 microM, GDC killed >95% of the breast cancer cells compared to 25% for Adriamycine. In prostate cancer cells, GDC killed approximately 55% of the cells at 0.1 microM and 100% of the cells at 0.5 microM compared to approximately 22 and approximately 62%, respectively, for adriamycin. Unconjugated aminoguanidine and agmatine did not seem to affect tumor cell growth even at high concentrations (mM). Polymer- conjugated guanidine is a potentially useful template for the construction of therapeutic tumor targeting cytotoxic agents.


Assuntos
Antineoplásicos/farmacologia , Dextranos/farmacologia , Guanidina/farmacologia , Linhagem Celular Tumoral , Humanos , Poliaminas/farmacologia
14.
Opt Lett ; 34(17): 2631-3, 2009 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-19724514

RESUMO

Improving the resolution in x-ray microscopes is of high priority to enable future applications in nanoscience. However, high-resolution zone-plate optics often have low efficiency, which makes implementation in laboratory microscopes difficult. We present a laboratory x-ray microscope based on a compound zone plate. The compound zone plate utilizes multiple diffraction orders to achieve high resolution while maintaining reasonable efficiency. We analyze the illumination conditions necessary for this type of optics in order to suppress stray light and demonstrate microscopic imaging resolving 25 nm features.


Assuntos
Desenho de Equipamento/instrumentação , Microscopia/instrumentação , Óptica e Fotônica , Algoritmos , Desenho de Equipamento/métodos , Processamento de Imagem Assistida por Computador , Microscopia/métodos , Dispositivos Ópticos , Fótons , Difração de Raios X , Raios X
15.
Nat Lang Linguist Theory ; 37(1): 91-122, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30774171

RESUMO

This paper focuses on passive symmetry effects in Germanic. We describe two large-sample judgment experiments with native speakers of Norwegian and Swedish, two partially symmetric passive languages. The results fail to support predictions of Anagnostopoulou's (2003) seminal locality approach to passive symmetry in these languages. We propose that constraints on object ordering in these varieties are better modeled on a revised version of classic case-based theories. On this approach, patterns of object ordering are governed by variation in the way that case is assigned to objects. In addition, the Norwegian results suggest a shape conservation effect in object shift contexts not previously reported in the literature. Theme-recipient orders in Norwegian object shift contexts are available for just those speakers who also accept theme-recipient orders in active non-object shift contexts. This object ordering constraint applies in the same environment that another, much better described ordering constraint applies, namely Holmberg's Generalization effects. We show that these results are explained by Fox and Pesetsky's (2005) cyclic linearization algorithm together with the assumption that theme-recipient orders vP-internally reflect short theme-movement above the recipient.

16.
Oncol Rep ; 20(1): 151-4, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18575731

RESUMO

Somatostatin (SMS), binds to its specific receptors (SSTRs) and transduces growth inhibitory, anti-secretory and apoptotic signals. Several human cancers express SSTRs, including prostate cancer, and therefore SMS is of interest for anti-cancer therapy. DNA methylation and histone modifications are involved in normal cell development, gene imprinting and human carcinogenesis. Reversing DNA methylation is an attractive therapeutic possibility, since epigenetic modifications change gene expression without changing the gene function. DNA methylation inhibitors such as 5-aza-2'-deoxycytidine (5'-aza, decitabine) have been used to treat several types of haematological malignancies. Histone deacetylase inhibitors such as trichostatin (TSA), are a new class of 'targeted anti-cancer agents'. TSA and decitabine can induce growth arrest, apoptosis or terminal differentiation in a variety of solid and haematological cancers in advanced disease patients. In the present study, the LNCaP cell line (prostate cancer) was incubated with SMS or Somadex (an SMS polymer conjugate) for three days, 1 nM per day, and the untreated cells were the negative control. For DNA demethylation, cells were grown in the presence of 2.5 microM 5-aza for 120 h, and re-fed with 5-aza-containing fresh medium at day 3. The total incubation time with 5-aza was 120 h. TSA at 1.0 microM was added into the cultured cells for 24 h. The combined treatment of 5-aza and TSA was performed by incubating the cells with 5-aza for 120 h followed by a 24-h exposure to TSA. Using cDNA obtained from these cell lines, the difference in the expression level of SSTR mRNA transcripts before and after 5-aza and TSA treatments was analyzed by RT-PCR. An increased induction of mRNA expression of the five SSTR subtypes was observed in the LNCaP cells when incubated with SMS/Somadex (dose-dependent). The inhibition of DNA methylation and histone acetylation resulted in the up-regulation of SSTR5 mRNA expression. The results demonstrate a positive feedback loop between SMS and its receptors. This regulation pathway may enhance the anti-tumor activity of somatostatin. To benefit from this effect in a clinical setting, the dose, dose frequency and pan affinity of the SMS derivative are important factors. The epigenetic manipulation with DNA methylation or histone deacetylase inhibitors, combined with SMS, may offer a novel alternative for the treatment of advanced prostate cancer.


Assuntos
Azacitidina/análogos & derivados , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ácidos Hidroxâmicos/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Receptores de Somatostatina/genética , Somatostatina/farmacologia , Azacitidina/farmacologia , Linhagem Celular Tumoral , Metilação de DNA , Decitabina , Inibidores de Histona Desacetilases , Humanos , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , RNA Mensageiro/análise , Regulação para Cima
17.
J Mech Behav Biomed Mater ; 79: 46-52, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29272812

RESUMO

Calcium phosphate cements (CPCs) are clinically used as injectable materials to fill bone voids and to improve hardware fixation in fracture surgery. In vivo they are dynamically loaded; nonetheless little is known about their fatigue properties. The aim of this study was to, for the first time, investigate the fatigue performance of a high-strength, degradable (brushitic) CPC, and also evaluate the effect of cement porosity (by varying the liquid to powder ratio, L/P) and the environment (air at room temperature or in a phosphate buffered saline solution, PBS, at 37°C) on the fatigue life. At a maximum compressive stress level of 15MPa, the cements prepared with an L/P-ratio of 0.22 and 0.28ml/g, corresponding to porosities of approximately 12% and 20%, had a 100% probability of survival until run-out of 5 million cycles, in air. When the maximum stress level, or the L/P-ratio, was increased, the probability of survival decreased. Testing in PBS at 37°C led to more rapid failure of the specimens. However, the high-strength cement had a 100% probability of survival up to approximately 2.5 million cycles at a maximum compressive stress level of 10MPa in PBS, which is substantially higher than some in vivo stress levels, e.g., those found in the spine. At 5MPa in PBS, all specimens survived to run-out. The results found herein are important if clinical use of the material is to increase, as characterisation of the fatigue performance of CPCs is largely lacking from the literature.


Assuntos
Cimentos Ósseos , Fosfatos de Cálcio , Força Compressiva , Estresse Mecânico , Teste de Materiais
18.
Anticancer Res ; 38(3): 1531-1537, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29491082

RESUMO

BACKGROUND/AIM: Prostate-specific membrane antigen (PSMA) is emerging as a target for treatment of castration-resistant prostate cancer (CRPC) while its up-regulated in the majority of CRPC tumors. The most common approach is targeted radionuclide therapy. MATERIALS AND METHODS: The PSMA binding pharmacophore Glu-Urea-Lysine (GUL) and lysine were conjugated to oxidized dextran with reductive amination and subsequently labelled with fluorosceinisothiocyanate (FITC). Three prostate cancer cell lines were used for binding studies, 22Rv1 (PSMA positive), DU145 (PSMA negative) and PC3 (PSMA negative). Binding images were obtained by fluorescence microscopy. RESULTS: PDC binding was recorded on the 22Rv1 cell line while the negative cell lines showed no or slight background binding. PDC binding could be inhibited by pre-incubation with a molar excess of unlabelled PDC. CONCLUSION: This is a novel template for PSMA targeted CRPC therapy, either using cytostatics or radionuclides.


Assuntos
Antígenos de Superfície/metabolismo , Glutamato Carboxipeptidase II/antagonistas & inibidores , Glutamato Carboxipeptidase II/metabolismo , Compostos Radiofarmacêuticos/metabolismo , Compostos Radiofarmacêuticos/farmacologia , Linhagem Celular Tumoral , Dextranos/química , Fluoresceína-5-Isotiocianato/química , Ácido Glutâmico/química , Humanos , Lisina/química , Masculino , Microscopia de Fluorescência , Terapia de Alvo Molecular/métodos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Ligação Proteica/efeitos dos fármacos , Compostos Radiofarmacêuticos/síntese química , Ureia/química
19.
Int J Oncol ; 30(5): 1173-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17390019

RESUMO

Some clinical results indicate that somatostatin (sms) might be useful in the treatment of advanced prostate cancer (HRPC). Because of its transient in vivo half-life only more stable derivatives of sms are of interest in this context. Recent studies have shown that natural sms can be conjugated to a carbohydrate (smsdx) with preservation of sms-like effects on the prostatic tumor cell proteome. The present study identifies some of the affected proteins in an effort to elucidate pathways and proteins that might be of importance for the potential usefulness of sms treatment in HRPC. After incubating the LNCaP cell-line with sms14/smsdx, comparative proteomics was used for analysing and identifying affected proteins. Protein expression patterns were analysed with two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. Catalytic mitochondrial and mitochondrial-associated proteins were significantly affected (fold change approximately 2 or higher) and they were in general up-regulated. Apoptosis-related proteins were both up-regulated (VDAC1, VDAC2) and down-regulated (PRDX2, TCTP). The fold change was >2 for PRDX2 and <2 for the others. There was a strong agreement between sms and smsdx on the up- and down-regulation of proteins. Sms/smsdx triggered up-regulation of catalytic mitochondrial proteins and seemed to affect apoptosis-related proteins. This could indicate important pathways on which smsdx might be able to curb the progression of HRPC. The results encourage a pending clinical phase II study.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/tratamento farmacológico , Proteoma , Proteômica/métodos , Somatostatina/farmacologia , Catálise , Linhagem Celular Tumoral , Progressão da Doença , Eletroforese em Gel Bidimensional , Humanos , Masculino , Mitocôndrias/metabolismo , Proteínas de Neoplasias/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Proteína Tumoral 1 Controlada por Tradução
20.
Rev Sci Instrum ; 78(2): 026103, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17578152

RESUMO

We demonstrate a laboratory-scale arrangement for rapid and accurate measurements of the absolute and local efficiency of soft x-ray micro zone plates in the water window. This in-house instrument is based on a single-line lambda = 2.88 nm liquid-jet laser-plasma source. Measurements are performed by a simultaneous comparison of first diffraction-order photon flux with the flux in a calibrated reference signal. This arrangement eliminates existing source emission fluctuations. The performance of the method is demonstrated by the result from measurements of two approximately 55 microm diameter nickel micro zone plates, showing a groove efficiency of 12.9% +/- 1.1% and 11.7% +/- 1.0%. Furthermore, we show that spatially resolved efficiency mapping is an effective tool for a detailed characterization of local zone plate properties. Thus, this laboratory-scale instrument allows rapid feedback to the fabrication process which is important for future improvements.

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