RESUMEN
Interleukin-2 (IL-2) has been used clinically for the treatment of some malignancies, but the toxicities associated with systemic IL-2 therapy are a major challenge. Here we have determined whether transcriptional targeting of IL-2 to breast cancer (BrCa) using an engineered human mammaglobin promoter/enhancer (MPE2) is a feasible option for reducing IL-2-associated toxicities while still achieving a meaningful antitumor effect. We have constructed nonreplicating adenovirus vectors encoding either a reporter gene (luciferase) or human IL-2 (hIL-2) complementary DNA under control of the MPE2 sequence, the murine cytomegalovirus immediate early (MCMV) promoter or the human telomerase reverse transcriptase (hTERT) promoter. Luciferase and hIL-2 complementary DNAs under the control of the MPE2 sequence in adenovirus vectors were expressed at high levels in BrCa cells and at lower levels in normal cells of human and murine origin. Cancer specificity of the hTERT promoter was found to be similar to that of the MPE2 promoter in cells of human origin, but reduced specificity in murine cells. The MPE2 regulatory sequence demonstrated excellent tissue specificity in a mouse tumor model. Whereas the MCMV promoter-controlled IL-2 vector generated high liver toxicity in mice, the MPE2-controlled IL-2 vector generated little or no liver toxicity. Both IL-2 vectors exerted significant tumor growth delay; however, attempts to further enhance antitumor activity of the IL-2 vectors by combining with the proapoptotic drug procaspase activating compound 1 (PAC1) were unsuccessful.
Asunto(s)
Adenoviridae/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Elementos de Facilitación Genéticos , Vectores Genéticos/genética , Interleucina-2/genética , Regiones Promotoras Genéticas , Secretoglobinas/genética , Animales , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/terapia , Línea Celular Tumoral , Terapia Combinada , Femenino , Expresión Génica , Genes Reporteros , Terapia Genética , Humanos , Ratones , Telomerasa/genética , Carga TumoralRESUMEN
Despite the tremendous potential of adenovirus (Ad) as a delivery vector for cancer gene therapy, its use in clinical settings has been limited, mainly as a result of the limited infectivity in many tumors and the wide tissue tropism associated with Ad. To modify the tropism of the virus, we have inserted the epidermal growth factor-like domain of the human heregulin-α (HRG) into the HI loop of Ad5 fiber. This insertion had no adverse effect on fiber trimerization nor did it affect incorporation of the modified fiber into infectious viral particles. Virions bearing modified fiber displayed growth characteristics and viral yields indistinguishable from those of wild-type (wt) virus. Most importantly, HRG-tagged virions showed enhanced infection of cells expressing the cognate receptors HER3/ErbB3 and HER4/ErbB4. This was significantly reduced in the presence of soluble HRG. Furthermore, HER3-expressing Chinese hamster ovary (CHO) cells were transduced by the HRG-modified virus, but not by wt virus. In contrast, CHO cells expressing the coxsackie-Ad receptor were transduced with both viruses. However, infection of an in vivo breast cancer xenograft model after intratumoral injection was similar with both viruses, suggesting that the tumor microenvironment and/or the route of delivery have important roles in infection of target cells with fiber-modified Ads.
Asunto(s)
Adenoviridae/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/virología , Receptor ErbB-3/metabolismo , Adenoviridae/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Cricetinae , Femenino , Expresión Génica , Técnicas de Transferencia de Gen , Humanos , Inyecciones Intralesiones , Ratones , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Ryster Optik occlusive folia were applied in 75 children with lowgrade amblyopia. Improvement of the visual acuity and binocular vision were achieved in all cases.