RESUMO
Cytoplasmic serine/threonine Pim kinases have emerged as important modulators of immune regulation and oncology. However, their regulatory roles in bone remodeling remain obscure. Here, we aimed to determine the roles of Pim kinases in periodontal disease (PD), focusing on the regulation of osteoclastogenesis and bone resorptive activity. We investigated Pim kinases expression in PD by analyzing data from the online Gene Expression Omnibus database and using ligature-induced periodontitis mouse model. The expression of Pim kinases during receptor activator of nuclear factor kB ligand (RANKL)-induced osteoclastogenesis was assessed in mouse bone marrow-derived macrophages (BMMs) using reverse transcription polymerase chain reaction. Osteoclast differentiation and bone resorption activity were respectively verified by tartrate-resistant acid phosphatase staining and dentin disc-based bone resorption assays. We silenced and overexpressed Pim-2 using small interfering RNA (siRNA) and retroviral vector, respectively, to investigate the molecular mechanisms underlying Pim-2 regulation in RANKL-induced osteoclastogenesis and bone resorption activity. Upregulated expression of Pim-2 was observed in both patients with PD and periodontitis-affected mouse gingival tissues. siRNA-mediated silencing of Pim-2 in BMMs diminished RANKL-induced resorptive activity without affecting osteoclastogenesis. Moreover, RANKL-triggered stimulation of a3 isoform, which is a subunit of vacuolar-type ATPase, was selectively attenuated in BMMs on silencing Pim-2. The overexpression of Pim-2 with a retroviral vector stimulated the a3 subunit, thus inducing bone resorption activity. Taken together, these results suggest that Pim-2 acts as a major modulator of osteoclastic activity by regulating a3 isoform expression in PD.
Assuntos
Reabsorção Óssea , Doenças Periodontais , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas , ATPases Vacuolares Próton-Translocadoras , Animais , Reabsorção Óssea/genética , Reabsorção Óssea/metabolismo , Diferenciação Celular , Inativação Gênica , Camundongos , Osteoclastos/metabolismo , Doenças Periodontais/genética , Doenças Periodontais/metabolismo , Periodontite/genética , Periodontite/metabolismo , Isoformas de Proteínas/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Ligante RANK/metabolismo , RNA Interferente Pequeno/genética , ATPases Vacuolares Próton-Translocadoras/metabolismoRESUMO
Previous reports suggest that plasminogen activator inhibitor-1 (PAI-1) promotes airway remodeling and that human and mouse mast cells (MCs) are an important source of PAI-1. In the present study we investigated MC-epithelial cell (EC) interactions in the production of PAI-1. We stimulated the human MC line LAD2 with IgE-receptor cross-linking and collected the supernatants. We incubated the human bronchial EC line BEAS-2B with the LAD2 supernatants and measured the level of PAI-1. When the supernatants from IgE-stimulated LAD2 were added to BEAS-2B, there was a significant enhancement of PAI-1 production by BEAS-2B. When we treated the MC supernatants with a transforming growth factor (TGF)-ß1 neutralizing antibody, the MC-derived induction of PAI-1 from BEAS-2B was completely abrogated. Although TGF-ß1 mRNA was constitutively expressed in resting LAD2, it was not highly induced by IgE-mediated stimulation. Nonetheless, active TGF-ß1 protein was significantly increased in LAD2 after IgE-mediated stimulation. Active TGF-ß1 produced by primary cultured human MCs was significantly reduced in the presence of a chymase inhibitor, suggesting a role of MC chymase as an activator of latent TGF-ß1. This study indicates that stimulation of human MCs by IgE receptor cross-linking triggers activation of TGF-ß1, at least in part via chymase, which in turn induces the production of PAI-1 by bronchial ECs. Our data suggest that human MCs may play an important role in airway remodeling in asthma as a direct source of PAI-1 and by activating bronchial ECs to produce further PAI-1 via a TGF-ß1-mediated activation pathway.
Assuntos
Asma/metabolismo , Brônquios/metabolismo , Comunicação Celular , Células Epiteliais/metabolismo , Mastócitos/metabolismo , Inibidor 1 de Ativador de Plasminogênio/biossíntese , Serpina E2/biossíntese , Fator de Crescimento Transformador beta1/metabolismo , Animais , Asma/patologia , Brônquios/patologia , Linhagem Celular , Quimases/metabolismo , Células Epiteliais/patologia , Humanos , Imunoglobulina E/metabolismo , Mastócitos/patologia , Camundongos , RNA Mensageiro/biossínteseRESUMO
Here, we report the successful incorporation of group I elements (K, Na, Li) to ZnO nanowires. Three distinct (2, 4, and 6 wt.%) doping concentrations of group I elements have been used to generate high piezoelectric voltage by employing a vertically integrated nanowire generator (VING) structure. X-ray photoelectron spectra (XPS) indicated the seepage of dopants in ZnO nanowires by substitution of Zn. Shallow acceptor levels (LiZn, NaZn, KZn) worked as electron trapping centers for intrinsically n-type ZnO nanowires. Free moving electrons caused a leakage current through the nanowires and depleted their piezoelectric potential. Reverse leakage current is a negative factor for piezoelectric nanogenerators. A reduction in reverse leakage current signifies the rise in output voltage. A gradual rise in output voltage has been witnessed which was in accordance with various doping concentrations. K-doped ZnO nanowires have generated voltages of 0.85 V, 1.48 V, and 1.95 V. For Na-doped ZnO nanowires, the voltages were 1.23 V, 1.73 V, and 2.34 V and the voltages yeilded for Li-doped ZnO nanowires were 1.87 V, 2.63 V, and 3.54 V, respectively. Maximum voltage range has been further enhanced by the surface enrichment (oxidized with O2 molecules) of ZnO nanowires. Technique has been opted to mitigate the screening effect during an external stress. After 5 h of oxidation in a sealed chamber at 100 ppm, maximum voltage peaks were pronounced to 2.48 V, 3.19 V, and 4.57 V for K, Na, and Li, respectively. A low-cost, high performance mechanical transducer is proposed for self-powered devices.
RESUMO
Comprehension of visually presented sentences in fluent bilinguals was studied with functional magnetic resonance imaging (fMRI) using a set of conceptually similar sentences in two orthographically and phonologically distinct languages, Mandarin and English. Responses were monitored during scanning. Sentence comprehension in each language was compared to fixation in nine subjects and Tamil-like pseudo-word strings in five subjects. Spatially congruent activations in the prefrontal, temporal, and superior parietal regions and in the anterior supplementary motor area were observed for both languages and in both experiments at the individual and group levels of analysis. Proficient bilinguals exposed to both languages early in life utilize common neuroanatomical regions during the conceptual and syntactic processing of written language irrespective of their differences in surface features.
Assuntos
Encéfalo/fisiologia , Idioma , Imageamento por Ressonância Magnética , Leitura , Adolescente , Adulto , Comportamento/fisiologia , Encéfalo/anatomia & histologia , HumanosRESUMO
BACKGROUND: In a science classroom, students do not simply learn scientific ways of doing, knowing, and reasoning unless they find ways of appropriating scientific discourse. In the Next Generation Science Standards, major forms of scientific discourse are emphasized as a main part of the Science and Engineering Practices. To enhance student engagement in scientific discourse, teachers need to help students differentiate scientific ways of talking from everyday ways of talking. Thus, science teachers should be able to be aware of the differences to provide opportunities for students to engage in scientific discourse. RESULTS: In this study, the classroom discourse analysis tool (CDAT) was developed to help science teachers and educators identify the patterns of their classroom discourse with the lens of scientific reasoning. The CDAT suggests a new way of discourse pattern finding with the two-dimensional graphic organizer and the quantitative data produced by the coding. To pilot the CDAT analysis, 13 videos and transcripts of two middle and one high school teachers' physical science classes were viewed and analyzed. The results from CDAT coding show illustrative information that characterizes the classroom discourse patterns in relation to scientific reasoning and teachers' questioning and feedback. A coded CDAT table shows what reasoning components used in the classroom dialogs between the teacher and students. It also shows how students engaged in the dialogs with the variations of their answers by the teacher's question and feedback. CONCLUSION: The results show the patterns of students' responses strongly depend on teacher's question or feedback. In addition, this analysis also generates various quantitative data that represent certain characteristics of the classroom discourse, i.e., length of dialog and the number of reasoning components used. The possible implications of CDAT analysis are to explore the relationships between teachers' discourse patterns and students' achievement along with changes in their reasoning skills. Student attitudinal outcomes such as motivations, interests, or self-efficacy could also be compared by the classroom discourse patterns revealed by CDAT. CDAT analysis itself can also be used in a teacher professional development as an intervention to help teachers see their classroom discourse patterns.
RESUMO
AIMS: Our previous studies of tonsillar cancers from New South Wales, Australia, and Jilin Province in the north-east of China, provided evidence that the proportion of these cancers attributable to human papillomavirus (HPV) varies geographically. This study provides the first data on HPV in tonsillar cancers from Hong Kong. METHODS: A total of 49 Hong Kong tonsillar cancers were analysed for HPV DNA by PCR/sequencing and for p16(INK4A), retinoblastoma (pRb) protein, cyclin D1 and p53 expression by semiquantitative immunohistochemistry as evidence of virus causality. Results were compared with those from New South Wales and Jilin Province. RESULTS: Of the 31 Hong Kong cancers with amplifiable DNA, nine (29%) were HPV positive by PCR compared with 46% from New South Wales and 0% from Jilin Province. HPV positivity correlated with female gender, young age, over-expression of p16(INK4A) and loss of pRb and cyclin D1. Five-year disease-specific survival for patients with HPV positive and HPV negative cancers was 82 and 42%, respectively. Relationships between HPV status and cell protein expression in Hong Kong cancers were consistent with those from New South Wales and Jilin Province. The proportion of HPV-associated cancers reflected the relative incidence of oropharyngeal cancer in these regions. CONCLUSIONS: HPV is responsible for a small proportion of tonsillar cancers in Hong Kong patients. Differences in the proportions of tumours attributable to HPV in Hong Kong, New South Wales and Jilin Province may be due to environmental, cultural or genetic factors in the different populations.
Assuntos
Neoplasias de Células Escamosas/virologia , Infecções por Papillomavirus/epidemiologia , Neoplasias Tonsilares/epidemiologia , Neoplasias Tonsilares/virologia , Infecções Tumorais por Vírus/epidemiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Transformação Celular Neoplásica , Ciclina D , Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Ciclinas/biossíntese , DNA Viral/análise , Feminino , Hong Kong/epidemiologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias de Células Escamosas/epidemiologia , Papillomaviridae , Reação em Cadeia da Polimerase , Proteína do Retinoblastoma/biossíntese , Proteína Supressora de Tumor p53/biossínteseRESUMO
We describe a new scaffold-free three-dimensional (3D) cell culture model using cholesteryl ester based lyotropic liquid crystal (LC) substrates. Keratinocytes were deposited randomly on the LC surface where they self-assembled into 3D microtissues or keratinospheroids. The cell density required to form spheroids was optimized. We investigated cell viability using dead/live cell assays. The adhesion characteristics of cells within the microtissues were determined using histological sectioning and immunofluorescence staining. Fourier transform infrared spectroscopy (FTIR) was used to characterize the biochemistry of the keratinospheroids. We found that both cells and microtissues could migrate on the LC surface. The viability study indicated approximately 80% viability of cells in the microtissues up to 20 days of culture. Strong intercellular adhesion was observed in the stratification of the multi-layered microspheroids using field emission-scanning electron microscopy (FE-SEM) and histochemical staining. The cytoskeleton and vinculins of the cells in the microtissues were expressed diffusely, but the microtissues were enriched with lipids and nucleic acids, which indicates close resemblance to the conditions in vivo. The basic 3D culture model based on LC may be used for cell and microtissue migration studies in response to cytochemical treatment.
Assuntos
Técnicas de Cultura de Células/métodos , Queratinócitos/citologia , Cristais Líquidos , Engenharia Tecidual , Linhagem Celular , Sobrevivência Celular , Imunofluorescência , Humanos , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
An eight-nation cooperative epidemiological study revealed the Asian and African features of sarcoidosis. Almost every country reported from several to less than 30 cases, except for Japan which had already collected over 3,000 cases. Not a single case was found in the mass x-ray surveys conducted by several countries on a large scale (Tables 1 and 2). Although the number of the cases included in this study were small, this information is the first of this kind for Asia and Africa.
Assuntos
Sarcoidose/epidemiologia , África , Ásia , HumanosRESUMO
The Implicit Association Test (IAT) examines the differential association of two object categories (e.g. flower and insect) with attribute categories (e.g. pleasant and unpleasant). When items from congruent categories (e.g. flower + pleasant) share a response key, performance is faster and more accurate than when items from incongruent categories (e.g. insect + pleasant) share a key. Performing incongruent word classification engages inhibitory processes to overcome the prepotent tendency to map emotionally congruent items to the same response key. Using fMRI on subjects undergoing the IAT, we show that the left dorsolateral prefrontal cortex, and to a lesser extent the anterior cingulate cortex, mediate inhibitory processes where manipulation of word association is required.
Assuntos
Associação , Córtex Pré-Frontal/fisiologia , Adulto , Lateralidade Funcional/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Tempo de Reação/fisiologia , Testes de Associação de PalavrasRESUMO
OBJECT: This study was conducted to evaluate peripheral nerve regeneration through a conduit composed of a bioresorbable material (LactoSorb). METHODS: Sprague-Dawley rats weighing approximately 250 g were randomized into five groups. A 20-mm-long sciatic nerve gap was created, then it was bridged by a reverse nerve autograft (Group I), an empty silicone tube (Group II), a silicone tube containing a short (2-mm) interposed nerve segment (Group III), an empty LactoSorb conduit (Group IV), or a LactoSorb conduit containing a 2-mm interposed nerve segment (Group V). The intact sciatic nerve served as the control in each animal. At 16 weeks postoperatively, no nerve regeneration was observed through either the empty silicone tube or the empty LactoSorb conduit. There was regeneration in all animals receiving the reverse autograft as well as in all animals receiving the silicone or LactoSorb conduit containing the 2-mm interposed nerve segment. Effective regeneration was assessed based on histological, electrophysiological, and morphometric criteria. CONCLUSIONS: The results indicate that a conduit made of resorbable material will support sciatic nerve regeneration over a critical gap defect.
Assuntos
Materiais Biocompatíveis/uso terapêutico , Ácido Láctico/uso terapêutico , Regeneração Nervosa/fisiologia , Nervos Periféricos/transplante , Ácido Poliglicólico/uso terapêutico , Polímeros/uso terapêutico , Nervo Isquiático/fisiologia , Implantes Absorvíveis , Animais , Masculino , Modelos Animais , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-Dawley , Silicones/uso terapêuticoRESUMO
The nm23 gene is a putative tumour and metastasis suppressor gene. A number of studies have found that reduction of its expression is associated with increased metastatic potential in several human malignancies. Similarly, clinical studies have shown correlation between reduced nm23 protein expression and a poor prognosis. The aim of this study was to determine if a relationship exists between nm23 expression in primary cutaneous melanomas with or without cerebral metastases. Paraffin-embedded tissues were retrieved from 21 patients with primary cutaneous melanomas (n=21) and who subsequently developed cerebral metastases (n=24). Primary cutaneous melanomas with no regional or organ metastases within a 10 year period were used as control cases (n=34). Nm23 staining was localized in the cytoplasm of the tumour cells. Most of the control cases showed strong expression, whereas the majority of the primary melanomas with cerebral metastases showed no or weak expression of nm23. The cerebral metastases mostly showed strong expression. In summary, the results of this study may have significant prognostic implications for patients presenting with cutaneous melanoma. Patients with cutaneous melanomas with a low expression of nm23 appear to be more at risk of developing brain metastases.
Assuntos
Biomarcadores Tumorais/análise , Neoplasias Encefálicas/secundário , Regulação Neoplásica da Expressão Gênica , Melanoma/metabolismo , Núcleosídeo-Difosfato Quinase/metabolismo , Neoplasias Cutâneas/metabolismo , Citoplasma/metabolismo , Feminino , Humanos , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Nucleosídeo NM23 Difosfato Quinases , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Neoplasias Cutâneas/patologiaRESUMO
This review examines how blood oxygen level-dependent functional magnetic resonance imaging (fMRI) may be harnessed to study the brain when it engages in language processing tasks. This method makes clinical and scientific contributions to understanding language function. Issues such as the lateralisation of language function, brain plasticity in health, ageing and neurological disease, and as well as how 2 different languages are processed, may all be evaluated by fMRI.
Assuntos
Mapeamento Encefálico/métodos , Encéfalo/irrigação sanguínea , Idioma , Imageamento por Ressonância Magnética/métodos , Oxigênio/sangue , Encéfalo/anatomia & histologia , Meios de Contraste , Feminino , Humanos , Masculino , Pesquisa , Sensibilidade e Especificidade , SingapuraRESUMO
Hemorrhagic lumbar synovial cysts are not commonly reported in English literature. Post-resection recurrence of synovial cyst is unusual and therefore recurrence symptoms required repeat MRI or CT scan. We reported a case of hemorrhagic lumbar synovial cyst presented with neurological deficit that recovered initially after surgery but subsequently developed recurrent of symptoms at a higher level due to fibrous tissue.
Assuntos
Hemorragia/complicações , Cisto Sinovial/complicações , Dor nas Costas/etiologia , Feminino , Hemorragia/diagnóstico , Hemorragia/terapia , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia , Vértebras Lombares/cirurgia , Pessoa de Meia-Idade , Parestesia/etiologia , Radiografia , Recidiva , Cisto Sinovial/diagnóstico , Cisto Sinovial/terapiaRESUMO
Keratinocyte traction forces play a crucial role in wound healing. The aim of this study was to develop a novel cell traction force (CTF) transducer system based on cholesteryl ester liquid crystals (LC). Keratinocytes cultured on LC induced linear and isolated deformation lines in the LC surface. As suggested by the fluorescence staining, the deformation lines appeared to correlate with the forces generated by the contraction of circumferential actin filaments which were transmitted to the LC surface via the focal adhesions. Due to the linear viscoelastic behavior of the LC, Hooke's equation was used to quantify the CTFs by associating Young's modulus of LC to the cell induced stresses and biaxial strain in forming the LC deformation. Young's modulus of the LC was profiled by using spherical indentation and determined at approximately 87.1±17.2kPa. A new technique involving cytochalasin-B treatment was used to disrupt the intracellular force generating actin fibers, and consequently the biaxial strain in the LC induced by the cells was determined. Due to the improved sensitivity and spatial resolution (â¼1µm) of the LC based CTF transducer, a wide range of CTFs was determined (10-120nN). These were found to be linearly proportional to the length of the deformations. The linear relationship of CTF-deformations was then applied in a bespoke CTF mapping software to estimate CTFs and to map CTF fields. The generated CTF map highlighted distinct distributions and different magnitude of CTFs were revealed for polarized and non-polarized keratinocytes.
Assuntos
Técnicas Biossensoriais/instrumentação , Ésteres do Colesterol/química , Queratinócitos/citologia , Cristais Líquidos/química , Transdutores , Actinas/análise , Linhagem Celular , Desenho de Equipamento , Humanos , Estresse Mecânico , Vinculina/análiseRESUMO
BACKGROUND: Chronic hepatitis B patients (CHB) treated with adefovir were followed up to evaluate nephrotoxicity and its outcome. AIM: To assess the incidence of renal dysfunction during adefovir therapy in Asian patients and factors associated with it, and evaluate strategies to improve adefovir-related renal dysfunction and their impact on viral suppression. METHODS: Chronic hepatitis B clinic patients from a tertiary hospital on adefovir treatment, with their clinical and laboratory parameters were extracted from the hospital electronic clinical database in an observational study design. Patients were excluded if they had liver/renal transplant, baseline renal impairment or were on dialysis. Adefovir-related renal dysfunction was defined as adefovir-related abnormal serum creatinine (ARASC) > 125 µmol/L (males), >90 µmol/L (females); adefovir-related abnormal GFR <60 mL/min; and adefovir-related increased serum creatinine >0.5 mg/dL, without other known causes of nephrotoxicity. RESULTS: A total of 271/383 adefovir-treated patients were suitable for analysis and 33(12%) patients developed abnormal serum creatinine. Cumulative increase in proportion of patients with ARASC was 33.8% and GFR ≤60 mL/min was 38.3% by 6 years, while serum creatinine increase ≥0.5 mg/dL was 21.48% by 5 years. Using multivariate analysis, the only independent baseline predictor of ARASC was GFR ≤76.1 mL/min. Patients who had ARASC had similar levels of viral suppression to those who did not have ARASC. Those who had ARASC either continued adefovir (24%), switched therapy (24%) or had adefovir dose reduction (52%). ARASC resolved and GFR normalised in almost all patients after either switching therapy or reducing adefovir dose, with no difference between the two strategies (P = 0.737). Those with adefovir dose reduction had no significant increase in HBV DNA (P = 0.170). CONCLUSIONS: Adefovir-related renal dysfunction occurred in a significant number of adefovir-treated patients, but reduction of the dose led to renal improvement without compromising treatment efficacy.
Assuntos
Adenina/análogos & derivados , Antivirais/administração & dosagem , Hepatite B Crônica/tratamento farmacológico , Nefropatias/prevenção & controle , Organofosfonatos/administração & dosagem , Adenina/administração & dosagem , Adenina/efeitos adversos , Adulto , Antivirais/efeitos adversos , Povo Asiático , Creatinina/sangue , Relação Dose-Resposta a Droga , Feminino , Taxa de Filtração Glomerular , Hepatite B Crônica/sangue , Humanos , Nefropatias/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Organofosfonatos/efeitos adversosRESUMO
An elevated tumor tissue androgen level, which reactivates androgen receptor in recurrent prostate cancer, arises from the intratumor synthesis of 5α-dihydrotestosterone through use of the precursor steroid dehydroepiandrosterone (DHEA) and is fueled by the steroidogenic enzymes 3ß-hydroxysteroid dehydrogenase (3ß-HSD1), aldoketoreductase (AKR1C3), and steroid 5-alpha reductase, type 1 (SRD5A1) present in cancer tissue. Sulfotransferase 2B1b (SULT2B1b) (in short, SULT2B) is a prostate-expressed hydroxysteroid SULT that converts cholesterol, oxysterols, and DHEA to 3ß-sulfates. DHEA metabolism involving sulfonation by SULT2B can potentially interfere with intraprostate androgen synthesis due to reduction of free DHEA pool and, thus, conversion of DHEA to androstenedione. Here we report that in prostatectomy specimens from treatment-naive patients, SULT2B expression is markedly reduced in malignant tissue (P < .001, Mann-Whitney U test) compared with robust expression in adjacent nonmalignant glands. SULT2B was detected in formalin-fixed specimens by immunohistochemistry on individual sections and tissue array. Immunoblotting of protein lysates of frozen cancer and matched benign tissue confirmed immunohistochemistry results. An in-house-developed rabbit polyclonal antibody against full-length human SULT2B was validated for specificity and used in the analyses. Ligand-activated vitamin D receptor induced the SULT2B1 promoter in vivo in mouse prostate and increased SULT2B mRNA and protein levels in vitro in prostate cancer cells. A vitamin D receptor/retinoid X receptor-α-bound DNA element (with a DR7 motif) mediated induction of the transfected SULT2B1 promoter in calcitriol-treated cells. SULT2B knockdown caused an increased proliferation rate of prostate cancer cells upon stimulation by DHEA. These results suggest that the tumor tissue SULT2B level may partly control prostate cancer growth, and its induction in a therapeutic setting may inhibit disease progression.
Assuntos
Neoplasias da Próstata/enzimologia , Receptores de Calcitriol/fisiologia , Sulfotransferases/genética , Animais , Anticorpos/química , Anticorpos/imunologia , Especificidade de Anticorpos , Sequência de Bases , Calcitriol/fisiologia , Linhagem Celular Tumoral , Proliferação de Células , Pegada de DNA , Indução Enzimática , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Próstata/enzimologia , Próstata/patologia , Ligação Proteica , Elementos de Resposta , Análise de Sequência de DNA , Sulfotransferases/imunologia , Sulfotransferases/metabolismo , Análise Serial de TecidosRESUMO
Hsp90 inhibitor geldanamycin and parthenolide have been shown to induce apoptosis in cancer cells. However, the combined effect of geldanamycin and parthenolide on epithelial ovarian cancer cells has not been studied. In respect of cell death process, we investigated the promoting effect of parthenolide on geldanamycin-induced apoptosis in the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. Geldanamycin induced a decrease in Bid, Bcl-2, Bcl-xL and survivin protein levels; an increase in Bax and tumour suppressor p53 levels; loss of the mitochondrial transmembrane potential; cytochrome c release; activation of caspases (-8, -9 and -3); cleavage of PARP-1; and increase in the reactive oxygen species formation. Parthenolide enhanced geldanamycin-induced changes in the apoptosis-related protein levels, reactive oxygen species formation, nuclear damage and cell death. The combined effect was inhibited by the addition of oxidant scavengers. The results suggest that parthenolide may potentiate the apoptotic effect of geldanamycin on ovarian carcinoma cell lines by the activation of the caspase-8- and Bid-dependent pathway and the mitochondria-mediated apoptotic pathway. The apoptosis-promoting effect seems to be mediated by the stimulatory effect on the formation of reactive oxygen species.