RESUMEN
Previously, we generated a cancer-specific gene therapy system using adenovirus vectors (Adv) conjugated to polyethylene glycol (Adv-PEG). Here, we developed a novel Adv that targets both tumor tissues and tumor vasculatures after systemic administration by conjugating CGKRK tumor vasculature homing peptide to the end of a 20-kDa PEG chain (Adv-PEG(CGKRK)). In a primary tumor model, systemic administration of Adv-PEG(CGKRK) resulted in ~500- and 100-fold higher transgene expression in tumor than that of unmodified Adv and Adv-PEG, respectively. In contrast, the transgene expression of Adv-PEG(CGKRK) in liver was about 400-fold lower than that of unmodified Adv, and was almost the same as that of Adv-PEG. We also demonstrated that transgene expression with Adv-PEG(CGKRK) was enhanced in tumor vessels. Systemic administration of Adv-PEG(CGKRK) expressing the herpes simplex virus thymidine kinase (HSVtk) gene (Adv-PEG(CGKRK)-HSVtk) showed superior antitumor effects against primary tumors and metastases with negligible side effects by both direct cytotoxic effects and inhibition of tumor angiogenesis. These results indicate that Adv-PEG(CGKRK) has potential as a prototype Adv with suitable efficacy and safety for systemic cancer gene therapy against both primary tumors and metastases.
Asunto(s)
Adenoviridae/genética , Terapia Genética/métodos , Vectores Genéticos , Neoplasias Vasculares/terapia , Animales , Línea Celular Tumoral , Regulación de la Expresión Génica , Técnicas de Transferencia de Gen , Genes Virales , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Polietilenglicoles/química , Polietilenglicoles/uso terapéutico , Simplexvirus/genética , Simplexvirus/metabolismo , Timidina Quinasa/genética , Timidina Quinasa/metabolismo , Transducción Genética , TransgenesRESUMEN
We have developed a hydrogel patch, which could promote antigen penetration through stratum corneum (SC), and have demonstrated its safety and efficacy in animals and humans. For the availability improvement of our system, it is important to develop a device, which enhances antigen penetration through SC more efficiently. In this study, we have tried to collect the basic information involved in transcutaneous antigen delivery by investigating the immune event induced by our system and examining the effect of physical property of antigens or patch component on antigen penetration. A hydrogel patch delivered antigens through SC into skin, and some of Langerhans cells captured antigens, activated, and migrated to regional lymph nodes. We also showed that protein distribution into SC was regulated by various complexly-intertwined factors of proteins but not one particular parameter. Additionally, glycerin as the patch component contributed to the formation of SC hydration by patch application, which might be one of the factors of acceleration of protein penetration. On the basis of the present information, we are planning to modify the patch composition and establish the antigen modification technology for improvement in the efficacy of transcutaneous immunization.