RESUMO
BACKGROUND: The in vivo half-life of interferons (IFNs) is very short, and its extension would produce a better therapeutic outcome in IFN-based therapy. Delivery of IFN genes is one solution for providing a sustained supply. IFNs have a variety of functions, including the suppression of transgene expression, through interaction with IFN receptors (IFNRs). This suppression could prevent IFNs from being expressed from vectors delivered. Silencing the expression of IFNAR and IFNGR, the receptors for type I and II IFNs, respectively, in cells expressing IFNs may prolong transgene expression of IFNs. METHODS: Mouse melanoma B16-BL6 cells or mouse liver were selected as a site expressing IFNs (not a target for IFN gene therapy) and IFN-expressing plasmid DNA was delivered with or without small interfering RNA (siRNA) targeting IFNRs. RESULTS: Transfection of B16-BL6 cells with siRNA targeting IFNAR1 subunit (IFNAR1) resulted in the reduced expression of IFNAR on the cell surface. This silencing significantly increased the IFN-beta production in cells that were transfected with IFN-beta-expressing plasmid DNA. Similar results were obtained with the combination of IFN-gamma and IFNGR. Co-injection of IFN-beta-expressing plasmid DNA with siRNA targeting IFNAR1 into mice resulted in sustained plasma concentration of IFN-beta. CONCLUSIONS: These results provide experimental evidence that the RNAi-mediated silencing of IFNRs in cells expressing IFN, such as hepatocytes, is an effective approach for improving transgene expression of IFNs when their therapeutic target comprises cells other than those expressing IFNs.
Assuntos
Inativação Gênica , Terapia Genética , Melanoma Experimental/genética , RNA Interferente Pequeno/genética , Receptores de Interferon/genética , Transgenes/fisiologia , Animais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos , Hepatócitos/metabolismo , Interferon beta/metabolismo , Luciferases/metabolismo , Melanoma Experimental/patologia , Melanoma Experimental/terapia , Camundongos , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , Receptores de Interferon/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , TransfecçãoRESUMO
BACKGROUND AND AIMS: Elastomeric pumps are widely used to facilitate ambulatory chemotherapy, and studies have shown that they are safe and well received by patients. Despite these advantages, their end of infusion time can fluctuate significantly. The aim of this research was to observe the performance of these pumps in real practice and to evaluate patients' satisfaction. METHODS: This was a two-phase study conducted at three cancer units over 6 months. Phase-1 was an observational study recording the status of pumps at the scheduled disconnection time and noting remaining volume of infusion. Phase-2 was a survey of patients and their perception/satisfaction. Ethical approval was granted. RESULTS: A total of 92 cases were observed covering 50 cases disconnected at hospital and 42 disconnected at home. The infusion in 40% of hospital disconnection cases was slow, with patients arriving at hospital with unfinished pumps; 58% of these had an estimated remaining volume which exceeded 10 mL with 35% exceeded 20 mL. In 73% of these cases, and regardless of the remaining volume, the patient was disconnected and the pump was discarded. CONCLUSIONS: The performance of pumps varied, which affected nurse workload and patients' waiting-times. A smart system is an option to monitor the performance of pumps and to predict their accuracy.