Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
1.
Arthroplasty ; 3(1): 3, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34977465

RESUMO

BACKGROUND: Infections following arthroplasty are one of the major risks during this type of surgery. Moreover, the outbreak of coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus Disease 2), has developed into an unprecedented pandemic, posing enormous pressure on health-care providers around the world. CASE PRESENTATION: Four and half years after right hip arthroplasty, the patient came back to our attention with pain at the same hip. The instrumental examinations showed signs of cup detachment. After carefully analyzing the case, we decided to perform a sterile aspiration of the hip in the operating room under C-arm fluoroscopy. Microbiological examinations showed positivity for E. coli. The patient underwent surgery by which the prosthesis was removed and a spacer was implanted. A therapy with Cefotaxim 2 g three times a day for 6 weeks was then set, and then a total arthroplasty was performed. During this period, the COVID-19 pandemic occurred and therefore the patient received nasal-throat swabbing two times, and both yielded negative results. However, 1 week after the final surgery, his respiratory conditions deteriorated and chest X-ray and CT scan showed images of ground-glass opacification patterns (GGO). Due to the clinical symptoms and the characteristic images of the instrumental examinations, the patient was transferred to an observation ward. Thereafter, two more swab tests gave negative results. The patient was then transferred to the ward for patients with typical symptoms of COVID-19 but with negative swab tests for 2 weeks and was subsequently discharged home. CONCLUSION: The purpose of this case report was to point out the correct treatment of a PJI after the outbreak of COVID-19. Despite the ongoing COVID-19 pandemic, the guidelines in the case of periprosthetic hip infection further confirmed the correct management of the patient.

2.
Int J Womens Dermatol ; 3(3): 131-139, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28831422

RESUMO

Laser treatment is a relatively new and increasingly popular modality for the treatment of many dermatologic conditions. A number of conditions that predominantly occur in women and that have a paucity of effective treatments include rosacea, connective tissue disease, melasma, nevus of Ota, lichen sclerosus (LS), notalgia paresthetica and macular amyloidosis, and syringomas. Laser therapy is an important option for the treatment of patients with these conditions. This article will review the body of literature that exists for the laser treatment of women with these medical conditions.

3.
Br J Cancer ; 116(4): 489-500, 2017 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-28095394

RESUMO

BACKGROUND: Colorectal carcinoma (CRC) is the third most common cancer worldwide. Platinum-based anticancer compounds still constitute one mainstay of systemic CRC treatment despite limitations due to adverse effects and resistance development. Trabectedin has shown promising antitumor effects in CRC, however, again resistance development may occur. In this study, we aimed to develop strategies to circumvent or even exploit acquired trabectedin resistance in novel CRC treatment regimens. METHODS: Human HCT116 CRC cells were selected for acquired trabectedin resistance in vitro and characterised by cell biological as well as bioinformatic approaches. In vivo xenograft experiments were conducted. RESULTS: Selection of HCT116 cells for trabectedin resistance resulted in p53-independent hypersensitivity of the selected subline against cisplatin. Bioinformatic analyses of mRNA microarray data suggested deregulation of nucleotide excision repair and particularly loss of the ubiquitin ligase CUL4A in trabectedin-selected cells. Indeed, transient knockdown of CUL4A sensitised parental HCT116 cells towards cisplatin. Trabectedin selected but not parental HCT116 xenografts were significantly responsive towards cisplatin treatment. CONCLUSIONS: Trabectedin selection-mediated CUL4A loss generates an Achilles heel in CRC cancer cells enabling effective cisplatin treatment. Hence, inclusion of trabectedin in cisplatin-containing cancer treatment regimens might cause profound synergism based on reciprocal resistance prevention.


Assuntos
Cisplatino/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Proteínas Culina/genética , Dioxóis/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Tetra-Hidroisoquinolinas/uso terapêutico , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Proteínas Culina/antagonistas & inibidores , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Genes p53 , Células HCT116 , Humanos , RNA Interferente Pequeno/farmacologia , Trabectedina
4.
Dalton Trans ; 46(2): 329-332, 2017 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-27918050

RESUMO

Supramolecular Pt(ii) quadrangular boxes bind native and G-quadruplex DNA motifs in a size-dependent fashion. Three Pt molecular squares of distinct size show biological activity against cancer cells and heavily influence the expression of genes known to form G-quadruplexes in their promoter regions. The smallest Pt-box displays less activity but more selectivity for a quadruplex formed in the c-Kit gene.

5.
Food Funct ; 7(8): 3628-36, 2016 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-27485636

RESUMO

Erlotinib (Tarceva®) is a chemotherapeutic drug approved for the treatment of pancreatic cancer and non-small cell lung cancer. Its primary mode of action is the inhibition of the epidermal growth factor receptor (EGFR), a receptor tyrosine kinase (RTK). Recently, RTK-inhibiting polyphenols have been reported to interact synergistically with erlotinib. Furthermore some anthocyanidins and anthocyanin-rich berry extracts have been reported to inhibit tyrosine kinases, including the EGFR, which raises the question of potential interactions with erlotinib. Polyphenol-rich preparations such as berry- or soy-based products are commercially available as food supplements. In the present study we tested a bilberry extract, its major anthocyanin and potential intestinal degradation products, as well as genistein, with respect to possible interactions with erlotinib. Cell growth inhibition was assessed using the sulforhodamine B assay, while interactions with EGFR phosphorylation were analyzed by SDS-PAGE/western blotting with subsequent immunodetection. Genistein, bilberry extract, delphinidin-3-O-glucoside and delphinidin were found to antagonize erlotinib whereas phloroglucinol aldehyde was found to enhance cytostatic effects of the drug on human epithelial A431 cells. Genistein also antagonized the EGFR inhibitory effects of erlotinib, whereas bilberry anthocyanins showed no significant interactions in this regard. Our data indicate that different polyphenols are potentially able to impair the cytostatic effect of erlotinib in vitro. Genistein interacts via the modulation of erlotinib-mediated EGFR inhibition whereas bilberry anthocyanins modulated the growth-inhibitory effect of erlotinib without affecting EGFR phosphorylation, thus indicating a different mechanism of interference.


Assuntos
Citostáticos/efeitos adversos , Células Epiteliais/efeitos dos fármacos , Cloridrato de Erlotinib/efeitos adversos , Genisteína/farmacologia , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Antocianinas/farmacologia , Linhagem Celular Tumoral , Células Epiteliais/metabolismo , Receptores ErbB/metabolismo , Ácido Gálico/farmacologia , Glucosídeos/farmacologia , Humanos , Floroglucinol/farmacologia , Fosforilação , Glycine max/química , Vaccinium myrtillus/química
6.
Chem Sci ; 7(5): 3052-3061, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29997796

RESUMO

Nano-scale secondary ion mass spectrometry (NanoSIMS) enables trace element and isotope analyses with high spatial resolution. This unique capability has recently been exploited in several studies analyzing the subcellular distribution of Au and Pt anticancer compounds. However, these studies were restricted to cell culture systems. To explore the applicability to the in vivo setting, we developed a combined imaging approach consisting of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), NanoSIMS and transmission electron microscopy (TEM) suitable for multi-scale detection of the platinum distribution in tissues. Applying this approach to kidney and tumor samples upon administration of selected platinum(iv) anticancer prodrugs revealed uneven platinum distributions on both the organ and subcellular scales. Spatial platinum accumulation patterns were quantitatively assessed by LA-ICP-MS in histologically heterogeneous organs (e.g., higher platinum accumulation in kidney cortex than in medulla) and used to select regions of interest for subcellular-scale imaging with NanoSIMS. These analyses revealed cytoplasmic sulfur-rich organelles accumulating platinum in both kidney and malignant cells. Those in the tumor were subsequently identified as organelles of lysosomal origin, demonstrating the potential of the combinatorial approach for investigating therapeutically relevant drug concentrations on a submicrometer scale.

7.
J Biomed Nanotechnol ; 11(7): 1139-52, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26307837

RESUMO

Development of nanocarriers for effective drug delivery to molecular targets in tumor cells is a real problem in modern pharmaceutical chemistry. In the present work we used pristine C60 fullerene as a platform for delivery of anticancer drug doxorubicin (Dox) to its biological targets. The formation of a complex of C60 fullerene with Dox (C60 + Dox) is described and physico-chemical characteristics of such complex are presented. It was found that Dox conjugation with C60 fullerene leads to 1.5-2-fold increase in Dox toxicity towards various human tumor cell lines, compared with such effect when the drug is used alone. Cytotoxic activity of C60 + Dox complex is accompanied by an increased level of cell produced hydrogen peroxide at early time point (3 h) after its addition to cultured cells. At the same time, cellular production of superoxide radicals does not change in comparison with the effect of Dox alone. Cytomorphological studies have demonstrated that C60 + Dox complexes kill tumor cells by apoptosis induction. The results of in vivo experiments using Lewis lung carcinoma in mice confirmed the enhancement of the Dox toxicity towards tumor cells after drug complexation with C60 fullerene. The effect of such complex towards tumor-bearing mice was even more pronounced than that in the in vitro experiment with targeting human tumor cells. The tumor volume decreased by 2.5 times compared with the control, and an average life span of treated animals increased by 63% compared with control. The obtained results suggest a great perspective of application of C60 + Dox complexes for chemotherapy of malignant tumors.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Doxorrubicina/administração & dosagem , Fulerenos/administração & dosagem , Nanoconjugados/administração & dosagem , Neoplasias Experimentais/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fulerenos/química , Células HL-60 , Humanos , Células MCF-7 , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nanoconjugados/química , Nanoconjugados/ultraestrutura , Neoplasias Experimentais/patologia , Tamanho da Partícula , Resultado do Tratamento
8.
Cancer Lett ; 361(1): 112-20, 2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-25749419

RESUMO

Although triapine is promising for treatment of advanced leukemia, it failed against solid tumors due to widely unknown reasons. To address this issue, a new triapine-resistant cell line (SW480/tria) was generated by drug selection and investigated in this study. Notably, SW480/tria cells displayed broad cross-resistance against several known ABCB1 substrates due to high ABCB1 levels (induced by promoter hypomethylation). However, ABCB1 inhibition did not re-sensitize SW480/tria cells to triapine and subsequent analysis revealed that triapine is only a weak ABCB1 substrate without significant interaction with the ABCB1 transport function. Interestingly, in chemo-naive, parental SW480 cells short-time (24 h) treatment with triapine stimulated ABCB1 expression. These effects were based on activation of protein kinase C (PKC), a known response to cellular stress. In accordance, SW480/tria cells were characterized by elevated levels of PKC. Together, this led to the conclusion that increased ABCB1 expression is not the major mechanism of triapine resistance in SW480/tria cells. In contrast, increased ABCB1 expression was found to be a consequence of triapine stress-induced PKC activation. These data are especially of importance when considering the choice of chemotherapeutics for combination with triapine.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteína Quinase C/metabolismo , Piridinas/farmacologia , Tiossemicarbazonas/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Hibridização Genômica Comparativa , Metilação de DNA/efeitos dos fármacos , Humanos , Regiões Promotoras Genéticas/genética , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
9.
Br J Cancer ; 112(5): 783-92, 2015 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-25633038

RESUMO

BACKGROUND: Estimating the prognosis in malignant pleural mesothelioma (MPM) remains challenging. Thus, the prognostic relevance of Ki67 was studied in MPM. METHODS: Ki67 index was determined in a test cohort of 187 cases from three centres. The percentage of Ki67-positive tumour cells was correlated with clinical variables and overall survival (OS). The prognostic power of Ki67 index was compared with other prognostic factors and re-evaluated in an independent cohort (n=98). RESULTS: Patients with Ki67 higher than median (>15%) had significantly (P<0.001) shorter median OS (7.5 months) than those with low Ki67 (19.1 months). After multivariate survival analyses, Ki67 proved to be-beside histology and treatment-an independent prognostic marker in MPM (hazard ratio (HR): 2.1, P<0.001). Interestingly, Ki67 was prognostic exclusively in epithelioid (P<0.001) but not in non-epithelioid subtype. Furthermore, Ki67 index was significantly lower in post-chemotherapy samples when compared with chemo-naive cases. The prognostic power was comparable to other recently published prognostic factors (CRP, fibrinogen, neutrophil-to-leukocyte ratio (NLR) and nuclear grading score) and was recapitulated in the validation cohort (P=0.048). CONCLUSION: This multicentre study demonstrates that Ki67 is an independent and reproducible prognostic factor in epithelioid but not in non-epithelioid MPM and suggests that induction chemotherapy decreases the proliferative capacity of MPM.


Assuntos
Células Epitelioides/patologia , Antígeno Ki-67/metabolismo , Neoplasias Pulmonares/mortalidade , Mesotelioma/mortalidade , Neoplasias Pleurais/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Epitelioides/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Mesotelioma/tratamento farmacológico , Mesotelioma/metabolismo , Mesotelioma/patologia , Mesotelioma Maligno , Pessoa de Meia-Idade , Neoplasias Pleurais/tratamento farmacológico , Neoplasias Pleurais/metabolismo , Neoplasias Pleurais/patologia , Análise de Sobrevida , Resultado do Tratamento
10.
Ukr Biochem J ; 87(5): 72-82, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26717598

RESUMO

Landomycin A (LA) is a new antitumor antibiotic of angucycline group, possessing high antitumor activity against cancer cells of different origin, which induces early apoptosis in target cells. It was shown that under LA action the level of reactive oxygen species (ROS) in human T-leukemia cells had increased 5.6 times in comparison to control already at the 1st hour after the addition of studied antibiotic to the culture medium. At the 6th hour after incubation of cells with LA the nucleosomal DNA cleavage, chromatin condensation and nucleus fragmentation were observed, indicating apoptotic cell death. Catalase (scavenger of hydrogen peroxide), mannitol (scavenger of hydroxyl radicals) and superoxide dismutase (scavenger of superoxide radicals) reduced the level of ROS production under LA, suggesting the generation of H2O2, OH* and O2- radicals, respectively. It was revealed that catalase and mannitol effectively inhibited LA-mediated tumor cell death, increasing 2.5 times the percentage of alive cells in comparison to LA. However, superoxide dismutase had no significant inhibitory effect on cytotoxic activity of LA, indicating the minor role of superoxide anions in the implementation of antitumor activity of this antibiotic. Combination of catalase, mannitol and superoxide dismutase with LA increased 4-fold the percentage of alive cells in comparison to the action of LA. Dynamics of ROS formation confirms that the increase of ROS is a very rapid process, but at the same time it is not a direct consequence of apoptosis triggering, mediated by mitochondria.


Assuntos
Aminoglicosídeos/farmacologia , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Aminoglicosídeos/química , Antibióticos Antineoplásicos/química , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HL-60 , Humanos , Células Jurkat , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estrutura Molecular
11.
J Biomed Nanotechnol ; 10(7): 1369-81, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24804557

RESUMO

Severe toxic side effects and drug resistance are the major limitations of doxorubicin (Dox), one of the most potent anticancer agents in clinical use. Nanocarrier preparations offer the opportunity to overcome these drawbacks, which is reflected in the clinical approval of two liposomal Dox preparations. Additionally, there are many attempts to enhance the activity of Dox against multi-drug resistant (MDR) cancer cells. However, most of these strategies resulted in the increased uptake of Dox in resistant cells, only, while it remained unchanged in chemo-sensitive cells. Here, we present a new polymeric-phospholipidic hybrid delivery system which distinctly enhanced the accumulation and activity of Dox in all tested cancer cell lines including several MDR cell models. Notably, the resistance levels against Dox were reduced from about 6-fold to about 2-fold. Moreover, the new nanocarriers were shown to rapidly (within 10 min) and effectively transport Dox into resistant as well as sensitive cancer cells. Consequently, treatment with the new Dox-containing nanocarriers resulted in effective cell cycle arrest in G2/M phase and ROS-induced cell death induction. Finally, the new nanocarriers were tested against NK/Ly lymphoma and L1210 leukemia cells in vivo. In both cell models, the nanoformulation of Dox resulted in 100% cured animals already at low concentrations (0.1 mg/kg), while free Dox solely extended survival time. This indicates that the incorporation of phospholipids into PEGylated polymeric nanocarriers is a promising strategy to enhance efficacy and reduce toxicity of Dox treatment against both sensitive and resistant cancer models in vitro and in vivo.


Assuntos
Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Nanopartículas/química , Fosfolipídeos/química , Polímeros/química , Animais , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Feminino , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Camundongos , Oxirredução/efeitos dos fármacos
12.
J Biomed Nanotechnol ; 10(5): 877-84, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24734541

RESUMO

Ruthenium anticancer drugs belong to the most promising non-platinum anticancer metal compounds in clinical evaluation. However, although the clinical results are promising regarding both activity and very low adverse effects, the clinical application is currently hampered by the limited solubility and stability of the drug in aqueous solution. Here, we present a new nanoparticle formulation based on polymer-based micelles loaded with the anticancer lead ruthenium compound KP1019. Nanoprepared KP1019 was characterised by enhanced stability in aqueous solutions. Moreover, the nanoparticle formulation facilitated cellular accumulation of KP1019 (determined by ICP-MS measurements) resulting in significantly lowered IC50 values. With regard to the mode of action, increased cell cycle arrest in G2/M phase (PI-staining), DNA damage (Comet assay) as well as enhanced levels of apoptotic cell death (caspase 7 and PARP cleavage) were found in HCT116 cells treated with the new nanoformulation of KP1019. Summarizing, we present for the first time evidence that nanoformulation is a feasible strategy for improving the stability as well as activity of experimental anticancer ruthenium compounds.


Assuntos
Indazóis/administração & dosagem , Indazóis/química , Nanocápsulas/administração & dosagem , Nanocápsulas/química , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Compostos Organometálicos/administração & dosagem , Compostos Organometálicos/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Difusão , Composição de Medicamentos/métodos , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Nanocápsulas/ultraestrutura , Compostos de Rutênio , Resultado do Tratamento
13.
Br J Cancer ; 110(4): 984-90, 2014 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-24434429

RESUMO

BACKGROUND: To investigate the clinical utility of pretreatment plasma fibrinogen levels in malignant pleural mesothelioma (MPM) patients. METHODS: A retrospective multicenter study was performed in histologically proven MPM patients. All fibrinogen levels were measured at the time of diagnosis and clinical data were retrospectively collected after approval of the corresponding ethics committees. RESULTS: In total, 176 MPM patients (mean age: 63.5 years ± 10.4 years, 38 females and 138 males) were analysed. Most patients (n=154, 87.5%) had elevated (≥ 390 mg dl(-1)) plasma fibrinogen levels. When patients were grouped by median fibrinogen, patients with low level (≤ 627 mg dl(-1)) had significantly longer overall survival (OS) (19.1 months, confidence interval (CI) 14.5-23.7 months) when compared with those with high level (OS 8.5; CI 6.2-10.7 months). In multivariate survival analyses, fibrinogen was found to be an independent prognostic factor (hazard ratio 1.81, CI 1.23-2.65). Most interestingly, fibrinogen (cutoff 75th percentile per 750 mg dl(-1)) proved to be a predictive biomarker indicating treatment benefit achieved by surgery within multimodality therapy (interaction term: P=0.034). Accordingly, only patients below the 75th percentile benefit from surgery within multimodality therapy (31.3 vs 5.3 months OS). CONCLUSIONS: Fibrinogen is a novel independent prognostic biomarker in MPM. Most importantly, fibrinogen predicted treatment benefit achieved by surgery within multimodality therapy.


Assuntos
Biomarcadores Tumorais/sangue , Fibrinogênio/análise , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/cirurgia , Mesotelioma/sangue , Mesotelioma/cirurgia , Terapia Combinada , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Mesotelioma/tratamento farmacológico , Mesotelioma Maligno , Pessoa de Meia-Idade , Neoplasias Pleurais/sangue , Neoplasias Pleurais/tratamento farmacológico , Neoplasias Pleurais/cirurgia , Prognóstico , Estudos Retrospectivos
14.
Ukr Biokhim Zh (1999) ; 85(2): 33-44, 2013.
Artigo em Ucraniano | MEDLINE | ID: mdl-23808308

RESUMO

Development of novel nanoscale functionalized carriers is nowadays one of the most urgent problems in cancer treatment. The aim of our study was to compare the antineoplastic effect of free doxorubicin and its complex with a nanoscale polymeric carrier towards HTC116 colorectal carcinoma cells. It was established that application of the complex of poly(5-tret-butylperoxy)-5-methyl-1-hexene-3-in-co-glycydyl metacrylat)-graft-polyethyleneglycol (poly(VEP-GMA-PEG)-graft-PEG), where VEP--5-tret-butylperoxy)-5-methyl-1-hexene-3-in; GMA--glycydyl metacrylat; graft-PEG--graft-polyethyleneglycol accordingly, functionalized with phosphatidylcholine for doxorubicin delivery increased 10 times the efficiency of cytotoxic action of this drug, as compared wich such efficiency in case of the action of free doxorubicin. The encapsulated form of doxorubicin caused more intensive cleavage of the reparation enzyme PARP and longer delay in G2/M cell cycle arrest, compared to such effects of free doxorubicin. The developed carrier itself is non-toxic to the used mammalian cells and does not cause impairment in their cell cycle. A deletion in both alleles of p53 gene did not affect the antineoplastic action of doxorubicin that was immobilized on the nanoscale carrier. Thus, p53-dependent signaling pathways are not involved in the cytotoxic action of doxorubicin-carrier complex. It is suggested that novel nanoscale polymeric carrier poly(VEP-GMA-PEG)-graft-PEG functionalized with phosphatidylcholine could be a promising carrier for targeted delivery of anticancer drugs.


Assuntos
Doxorrubicina/farmacologia , Portadores de Fármacos/química , Nanopartículas/química , Polímeros/química , Apoptose/efeitos dos fármacos , Western Blotting , Técnicas de Cultura de Células , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Portadores de Fármacos/efeitos adversos , Humanos , Nanopartículas/efeitos adversos , Proteínas de Neoplasias/metabolismo , Polímeros/efeitos adversos
15.
Biochem Pharmacol ; 86(3): 361-77, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23747344

RESUMO

Destruxins (Dtx) are secondary metabolites of the entomopathogenic fungus Metarhizium anisopliae. Recently, Dtx came into focus of interest as anticancer therapeutics. However, data on human and especially on cancer cells are fragmentary. In order to successfully establish novel anticancer therapeutics, a broad knowledge on the cellular and molecular mechanisms underlying their activity is essential. Consequently, this study aimed to investigate the impact of the most common Dtx derivatives A, B and E on human cancer cell growth and survival with a focus on colon cancer cell models. Summarizing, the experimental data showed that (i) Dtx A and B exert potent antiproliferative activity in the micromolar and Dtx E in the nanomolar range in KB-3-1, A549, CaCo-2, and especially in HCT116 colon cancer cells, (ii) all three Dtx derivatives cause imbalance of cell cycle distribution, (iii) their cytostatic/cytotoxic effects are widely p53-independent but reduced by p21- and bax-deletion, respectively, (iv) cytotoxicity is based on intrinsic apoptosis induction and associated with phosphoinositide-3-kinase (PI3K)/Akt pathway inhibition, (v) anticancer activity of Dtx E but not Dtx A and B involves disturbance of the intracellular redox balance, (vi) Dtx inhibit the migration and tube formation of human endothelial cells indicating antiangiogenic potential, and (vii) all three Dtx derivatives possess ionophoric properties not differing in conductivity, ion selectivity and single channel kinetics. Thus, Dtx represent feasible, multifunctional anticancer drug candidates for preclinical development especially against colorectal cancer.


Assuntos
Inibidores da Angiogênese/química , Antineoplásicos/química , Depsipeptídeos/química , Proteínas Fúngicas/química , Metarhizium , Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Células CACO-2 , Proliferação de Células/efeitos dos fármacos , Depsipeptídeos/farmacologia , Relação Dose-Resposta a Droga , Proteínas Fúngicas/farmacologia , Células HCT116 , Células Endoteliais da Veia Umbilical Humana , Humanos
16.
Cell Death Dis ; 4: e561, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23538442

RESUMO

Glioblastoma multiforme (GBM) is the most lethal and common malignant human brain tumor. The intrinsic resistance of highly invasive GBM cells to radiation- and chemotherapy-induced apoptosis accounts for the generally dismal treatment outcomes. This study investigated ophiobolin A (OP-A), a fungal metabolite from Bipolaris species, for its promising anticancer activity against human GBM cells exhibiting varying degrees of resistance to proapoptotic stimuli. We found that OP-A induced marked changes in the dynamic organization of the F-actin cytoskeleton, and inhibited the proliferation and migration of GBM cells, likely by inhibiting big conductance Ca(2+)-activated K(+) channel (BKCa) channel activity. Moreover, our results indicated that OP-A induced paraptosis-like cell death in GBM cells, which correlated with the vacuolization, possibly brought about by the swelling and fusion of mitochondria and/or the endoplasmic reticulum (ER). In addition, the OP-A-induced cell death did not involve the activation of caspases. We also showed that the expression of BKCa channels colocalized with these two organelles (mitochondria and ER) was affected in this programmed cell death pathway. Thus, this study reveals a novel mechanism of action associated with the anticancer effects of OP-A, which involves the induction of paraptosis through the disruption of internal potassium ion homeostasis. Our findings offer a promising therapeutic strategy to overcome the intrinsic resistance of GBM cells to proapoptotic stimuli.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Glioblastoma/metabolismo , Subunidades alfa do Canal de Potássio Ativado por Cálcio de Condutância Alta/antagonistas & inibidores , Mitocôndrias/efeitos dos fármacos , Sesterterpenos/farmacologia , Actinas/antagonistas & inibidores , Actinas/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/patologia , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Homeostase/efeitos dos fármacos , Homeostase/fisiologia , Humanos , Subunidades alfa do Canal de Potássio Ativado por Cálcio de Condutância Alta/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Técnicas de Patch-Clamp , Potássio/metabolismo
17.
Waste Manag ; 33(4): 942-7, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23402897

RESUMO

Raw material supply is essential for all industrial activities. The use of secondary raw material gains more importance since ore grade in primary production is decreasing. Meanwhile urban stock contains considerable amounts of various elements. Photovoltaic (PV) generating systems are part of the urban stock and recycling technologies for PV thin film modules with CdTe as semiconductor are needed because cadmium could cause hazardous environmental impact and tellurium is a scarce element where future supply might be constrained. The paper describes a sequence of mechanical processing techniques for end-of-life PV thin film modules consisting of sandblasting and flotation. Separation of the semiconductor material from the glass surface was possible, however, enrichment and yield of valuables in the flotation step were non-satisfying. Nevertheless, recovery of valuable metals from urban stock is a viable method for the extension of the availability of limited natural resources.


Assuntos
Cádmio/isolamento & purificação , Reciclagem/métodos , Telúrio/isolamento & purificação , Fontes de Energia Elétrica , Semicondutores
18.
Br J Cancer ; 107(12): 1978-86, 2012 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-23169291

RESUMO

BACKGROUND: Activins control the growth of several tumour types including thoracic malignancies. In the present study, we investigated their expression and function in malignant pleural mesothelioma (MPM). METHODS: The expression of activins and activin receptors was analysed by quantitative PCR in a panel of MPM cell lines. Activin A expression was further analysed by immunohistochemistry in MPM tissue specimens (N=53). Subsequently, MPM cells were treated with activin A, activin receptor inhibitors or activin-targeting siRNA and the impact on cell viability, proliferation, migration and signalling was assessed. RESULTS: Concomitant expression of activin subunits and receptors was found in all cell lines, and activin A was overexpressed in most cell lines compared with non-malignant mesothelial cells. Similarly, immunohistochemistry demonstrated intense staining of tumour cells for activin A in a subset of patients. Treatment with activin A induced SMAD2 phosphorylation and stimulated clonogenic growth of mesothelioma cells. In contrast, treatment with kinase inhibitors of activin receptors (SB-431542, A-8301) inhibited MPM cell viability, clonogenicity and migration. Silencing of activin A expression by siRNA oligonucleotides further confirmed these results and led to reduced cyclin D1/3 expression. CONCLUSION: Our study suggests that activin A contributes to the malignant phenotype of MPM cells via regulation of cyclin D and may represent a valuable candidate for therapeutic interference.


Assuntos
Ativinas/antagonistas & inibidores , Antineoplásicos/farmacologia , Ciclina D/metabolismo , Mesotelioma/metabolismo , Mesotelioma/patologia , Neoplasias Pleurais/metabolismo , Neoplasias Pleurais/patologia , Western Blotting , Movimento Celular , Proliferação de Células , Sobrevivência Celular , Ciclina D/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Imuno-Histoquímica , Mesotelioma/tratamento farmacológico , Fenótipo , Fosforilação/efeitos dos fármacos , Neoplasias Pleurais/tratamento farmacológico , RNA Interferente Pequeno/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/metabolismo , Ensaio Tumoral de Célula-Tronco , Regulação para Cima
19.
Exp Cell Res ; 318(6): 768-78, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22237009

RESUMO

12(S)-Lipoxygenase (LOX) and its product 12(S)-hydroxyeicosatetraenic (HETE) acid have been implicated in angiogenesis and tumour invasion in several tumour types while their role in colorectal cancer progression has not yet been studied. We have analysed 12(S)-LOX expression in colorectal tumours and found gene expression up-regulated in colorectal cancer specimens for which the pathology report described involvement of inflammation. Using cell line models exposed to 12(S)-HETE or over-expressing 12(S)-LOX malignant cell growth as well as tumour cell migration was found to be stimulated. Specifically, Caco2 and SW480 cells over-expressing 12(S)-LOX formed fewer colonies from sparse cultures, but migrated better in filter-migration assays. SW480 LOX cells also had higher anchorage-independent growth capacity and a higher tendency to metastasise in vivo. Knock-down or inhibition of 12(S)-LOX inhibited cell migration and anchorage-independent growth in both 12(S)-LOX transfectants and SW620 cells that express high endogenous levels of 12(S)-LOX. On the cell surface E-cadherin and integrin-ß1 expression were down-regulated in a 12(S)-LOX-dependent manner disturbing cell-cell interactions. The results demonstrate that 12(S)-LOX expression in inflammatory areas of colorectal tumours has the capacity to induce an invasive phenotype in colorectal cancer cells and could be targeted for therapy.


Assuntos
Araquidonato 12-Lipoxigenase/genética , Movimento Celular/genética , Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/genética , Regulação para Cima , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/metabolismo , Araquidonato 12-Lipoxigenase/metabolismo , Células CACO-2 , Neoplasias Colorretais/metabolismo , Humanos , Fenótipo , Células Tumorais Cultivadas
20.
Clin Exp Allergy ; 41(11): 1579-86, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21729179

RESUMO

BACKGROUND: Experimental studies suggest that glutathione S-transferase (GST) genotypes modify nasal allergen responses induced by secondhand smoke (SHS) exposure. OBJECTIVE: We aimed to investigate whether GSTs affected systemic IgE and allergic rhinitis (AR) in SHS-exposed individuals from a population-based cohort. METHODS: Analyses comprised 2309 never-smokers from the Swiss study on air pollution and health in adults cohort, reporting SHS status at baseline and 11 years later. Outcomes were defined by total serum IgE≥100 kU/L, specific serum IgE determined by Phadiatop® ≥0.35 kU/L and self-reported AR. GSTP1 Ile105Val, GSTM1 and GSTT1 gene deletion genotypes were identified at the follow-up survey. RESULTS: After adjustment for relevant covariates, the homozygous GSTP1 105-Val genotype was negatively associated with high total IgE and high-specific IgE by Phadiatop®, notably in subjects persistently exposed to SHS (OR: 0.20, 95% CI 0.05-0.75; P=0.02, for high total IgE and OR: 0.29, 95% CI 0.10-0.89; P=0.03, for high specific IgE by Phadiatop®). Carrying at least one copy of the GSTM1 gene (non-null) showed a similar association for high specific IgE by Phadiatop® (OR: 0.41, 95% CI 0.22-0.76; P=0.004). No significant associations were found between GSTs and rhinitis. CONCLUSION AND CLINICAL RELEVANCE: In this large cohort, homozygosity for GSTP1 105-Val or carrying the GSTM1 non-null genotype decreased the risk of high total IgE or high specific IgE using Phadiatop® by nearly half in subjects exposed to SHS, as compared with subjects carrying opposite alleles. These findings underline the value of genetic susceptibility when evaluating the effects of environmental exposure on allergic illness. The potential long-term effects of persistent SHS exposure in genetically vulnerable individuals may be of public health relevance.


Assuntos
Genótipo , Glutationa Transferase/genética , Hipersensibilidade Imediata/genética , Rinite/genética , Poluição por Fumaça de Tabaco/efeitos adversos , Adulto , Estudos de Coortes , Feminino , Humanos , Hipersensibilidade Imediata/etiologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Rinite/etiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA