RESUMO
BACKGROUND: Because of the time and expense associated with the procedures and possible distress to the patient, cystoscopy or other imaging techniques are typically not used for bladder cancer detection before symptoms become present. Alternatively, commercial assays for urinary tumor markers exist but are marred by low sensitivity and high cost. There is a need for a simple and sensitive means of tumor detection, such as via the analysis of urine. METHODS: Plasmids encoding the secretable reporter Gaussia Luciferase (G.LUC), under the control of cmv, cox2 or opn promoters, were delivered via polyethylenimine into bladder tumor cells in culture and into the bladders of mice. Expression profiles of the reporter were recorded, the optimal times for reporter detection were determined and the relationship of reporter expression with tumor size was calculated. RESULTS: In vitro results showed that both the cox2 and opn promoters can drive significant expression of G.LUC in bladder carcinoma cells in a targeted fashion. In vivo results demonstrated that the cox2 promoter caused expression of G.LUC at detectable levels in the urine, with local signal maxima occurring at 48 and 72 h post-transfection. G.LUC levels in the urine had a 24-h periodicity, with the periodicity partly being the result of an agent secreted by tumor cells that served to mask the luciferase signal. CONCLUSIONS: Having shown tumor specificity and having been calibrated with respect to circadian expression patterns, the detection system shows great promise for future investigation of tumor presence both in the urinary bladder and other models of cancer.
Assuntos
Expressão Gênica , Técnicas de Transferência de Genes , Luciferases/genética , Regiões Promotoras Genéticas/genética , Neoplasias da Bexiga Urinária/genética , Animais , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , Copépodes/enzimologia , Copépodes/genética , Ciclo-Oxigenase 2/genética , Feminino , Humanos , Luciferases/metabolismo , Camundongos Endogâmicos C57BL , Neoplasias Experimentais/diagnóstico , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Osteopontina/genética , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/metabolismoRESUMO
Lysine-containing polymers have seen broad application due to their amines' inherent ability to bind to a range of biologically relevant molecules. The synthesis of multiple generations of polyester dendrimers bearing lysine groups on their periphery is described in this report. Their hydrolytic stabilities with respect to pH and time, their toxicity to a range of cell lines, and their possible application as nano-detoxification agents of organophosphate compounds are all investigated. These zeroth-, first-, and second-generation water-soluble dendrimers have been designed to bear exactly 4, 8, and 16 lysine groups, respectively, on their dendritic periphery. Such monodisperse bioactive polymers show potential for a range of applications including drug delivery, gene delivery, heavy metal binding, and the sequestration of organic toxins. These monodisperse bioactive dendrimers were synthesized using an aliphatic ester dendritic core (prepared from pentaerythritol) and protected amino acid moieties. This library of lysine-conjugated dendrimers showed the ability to efficiently capture the pesticide dichlorvos, confirming the potential of dendrimer-based antidotes to maintain acetylcholinesterase activity in response to poisoning events.
Assuntos
Dendrímeros/química , Diclorvós/química , Lisina/química , Animais , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio , Camundongos , Tamanho da Partícula , Polímeros/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
The delivery of genetic material to cells offers the potential to treat many genetic diseases. Cationic polymers, specifically poly(ethylene imine) (PEI), are promising gene delivery vectors due to their inherent ability to condense genetic material and successfully affect its transfection. However, PEI and many other cationic polymers also exhibit high cytotoxicity. To systematically study the effect of polymer architecture on gene delivery efficiency and cell cytotoxicity, a set of cyclic PEIs were prepared for the first time and compared to a set of linear PEIs of the exact same molecular weight. Subsequent in vitro transfection studies determined a higher transfection efficiency for each cyclic PEI sample when compared to its linear PEI analogue in addition to reduced toxicity relative to the branched PEI "gold standard" control. These results highlight the critical role that the architecture of PEI can play in both optimizing transfection and reducing cell toxicity.
