RESUMO
A recombinant soluble human urokinase receptor comprising amino acids 1-277 was cloned and transfected into CHO cells. The mutant protein (rec-uPAR277), purified from the CHO cell supernatant by affinity chromatography on immobilized urokinase (uPA), in a four-fold excess, completely abolished the binding of FITC-labeled pro-uPA to the human ovarian cancer cell line, OV-MZ-6. This invasive and tumorigenic cancer cell line expresses uPA, its inhibitor PAI-1, and the high-affinity receptor for uPA, uPAR. Rec-uPAR277 significantly reduced the proliferation of OV-MZ-6 cells in a concentration-dependent manner without altering the viability of the cells. Invasion of OV-MZ-6 cells tested in an in vitro Matrigel invasion assay was inhibited by rec-uPAR277 up to 75%. In conclusion, these results demonstrate that rec-uPAR277 can function as a scavenger for uPA in vitro by inhibiting proliferation and invasion of human cancer cells.
Assuntos
Receptores de Superfície Celular/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Animais , Células CHO , Divisão Celular , Linhagem Celular , Sobrevivência Celular , Cromatografia de Afinidade , Clonagem Molecular , Cricetinae , Cistadenocarcinoma/metabolismo , Cistadenocarcinoma/patologia , Feminino , Humanos , Mutagênese Sítio-Dirigida , Invasividade Neoplásica , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Inibidor 1 de Ativador de Plasminogênio/biossíntese , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/isolamento & purificação , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Transfecção , Células Tumorais CultivadasRESUMO
Urokinase-type plasminogen activator (uPA) is a protease involved in the process of tissue remodelling and cell migration in vitro. To explore whether uPA is a prerequisite for human ovarian cancer spread in vivo the expression of uPA was suppressed in human ovarian cancer cells by antisense phosphorothioate oligonucleotides (PS-ODN). The suppression of uPA expression was dependent on PS-ODN concentration and only observed in the presence of liposomes. This phenomenon seemed to be due to the fact that PS-ODNs were taken up by the cancer cells only in concert with liposomes as studied by fluorescently-labeled PS-ODNs using flow cytofluorometry and laser scanning microscopy. uPA-deprived cancer cells exhibited a significantly reduced invasive capacity in vitro compared with untreated cancer cells or cells treated with control PS-ODNs (P = 0.003). The intraperitoneal spread of the cancer cells in vivo was significantly diminished when nude mice were treated with uPA antisense PS-ODNs in comparison with control mice (P = 0.009). These results suggest that uPA expression may be required for spread of human ovarian cancer and that its inhibition could provide a therapeutic approach.
Assuntos
Antineoplásicos/farmacologia , Oligonucleotídeos Antissenso/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/enzimologia , Tionucleotídeos/farmacologia , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Animais , Sequência de Bases , Estudos de Viabilidade , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Dados de Sequência Molecular , Invasividade Neoplásica/prevenção & controle , Transplante de Neoplasias , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Peritoneais/patologia , Células Tumorais CultivadasRESUMO
Expression of urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (t-PA), their inhibitor PAI-1 and the uPA-receptor (uPAR) was characterized in six human tumor cell lines (OV-MZ-6, -10, -13, -15, -19 and OVCAR-3) established from patients with cystadenocarcinoma of the ovary. The invasive potential of the ovarian cancer cell lines determined in an in vitro invasion assay did neither correlate with the antigen level of uPA, t-PA, PAI-1 or uPAR nor with the cell surface uPA activity, however, did correlate with the cell surface-bound plasmin activity. The in vitro invasiveness of three cancer cell lines selected displaying a different pattern of uPA and uPAR expression was significantly inhibited by a recombinant soluble truncated form of the uPAR functioning as a scavenger for uPA. Our results suggest that the interference of the uPA/uPAR interaction leads to a reduced in vitro invasiveness of human ovarian cancer cells independent of the level of uPA and uPAR expression.
RESUMO
Speech understanding and subjective preference for three different speech coding strategies (spectral peak coding [SPEAK], continuous interleaved sampling [CIS], and advanced combination encoders [ACE]) were investigated in 11 post-lingually deaf adult subjects, using the Nucleus CI 24M cochlear implant system. Subjects were randomly assigned to two groups in a balanced crossover study design. The first group was initially fitted with SPEAK and the second group with CIS. The remaining strategies were tested sequentially over 8 to 10 weeks with systematic variations of number of channels and rate of stimulation. Following a further interval of 3 months, during which subjects were allowed to listen with their preferred strategy, they were tested again with all three strategies. Compound action potentials (CAPs) were recorded using neural response telemetry. Input/output functions in relation to increasing stimulus levels and inter-stimulus intervals between masker and probe were established to assess the physiological status of the cochlear nerve. Objective results and subjective rating showed significant differences in favour of the ACE strategy. Ten of the 11 subjects preferred the ACE strategy at the end of the study. The estimate of the refractory period based on the inter-stimulus interval correlated significantly with the overall performance with all three strategies, but CAP measures could not be related to individual preference of strategy or differences in performance between strategies. Based on these results, the ACE strategy can be recommended as an initial choice specifically for the Nucleus CI 24M cochlear implant system. Nevertheless, access to the other strategies may help to increase performance in individual patients.
Assuntos
Implante Coclear , Auxiliares de Audição , Perda Auditiva Neurossensorial/terapia , Percepção da Fala/fisiologia , Telemetria/métodos , Estimulação Acústica/instrumentação , Adulto , Desenho de Equipamento , Perda Auditiva Neurossensorial/cirurgia , Humanos , Pessoa de Meia-Idade , Mascaramento PerceptivoRESUMO
BACKGROUND: Complications and local extension of dentogenous and paranasal sinus infections most often involve the periorbit and frontal cranium. Because of the widespread use of antibiotics, intracranial extension of maxillofacial sinusitis is rarely seen today. Nevertheless, the clinician must be aware of the potential for these complications, because late recognition of this condition and delay in treatment can increase morbidity and mortality rates. CASE REPORT: A case report of sinogenic intracranial complications is presented, with sinogenic empyema, cerebritis, and subdural empyema. The mechanisms and potential for intracranial spread of infection from the frontal, sphenoid, and ethmoid sinuses are discussed. The management of complications is outlined, including the use of computed tomography and the role of surgical drainage.