RESUMEN
Human papillomavirus (HPV) types 16 and 18 are the major etiologic factors in the development of cervical epithelial neoplasia. Our study was designed to validate antiviral short interfering RNA (siRNA) targeting the E6 and E7 oncogenes as a potential chemosensitizer of cisplatin (cis-diaminedichloroplatinum II; CDDP) in cervical carcinoma. Specifically, the therapeutic efficacy of combination of CDDP and E6/E7-specific siRNA was assessed in an in vivo cervical cancer xenograft models. The combination of CDDP and E6/E7-specific siRNA had greater efficacy than the combination of CDDP and E6-specific siRNA especially in terms of inducing cellular senescence. Through in vitro and in vivo experiments, the mechanism of synergy between these two treatments was revealed, demonstrating that the combination of E6/E7-specific siRNA and CDDP therapy was significantly superior to either modality alone. In vitro, long-term exposure of HeLa cells to the combination of CDDP and E6/E7-specific siRNA induced apoptosis and cellular senescence. In vivo, E6/E7-specific siRNA potentiated the antitumor efficacy of CDDP via induction of apoptosis, senescence and antiangiogenesis. Our results suggest that E6/E7-specific siRNA may be an effective sensitizer of CDDP chemotherapy in cervical cancer.
Asunto(s)
Cisplatino/uso terapéutico , Interferencia de ARN , ARN Interferente Pequeño/genética , Neoplasias del Cuello Uterino/terapia , Alphapapillomavirus/genética , Alphapapillomavirus/fisiología , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Apoptosis/genética , Western Blotting , Línea Celular Tumoral , Cisplatino/farmacología , Terapia Combinada , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Células HeLa , Interacciones Huésped-Patógeno/genética , Humanos , Ratones , Ratones Desnudos , Proteínas Oncogénicas Virales/genética , Proteínas Oncogénicas Virales/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Carga Tumoral/efectos de los fármacos , Carga Tumoral/genética , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/virología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
In this study, we tested the use of cationic polymer derivatives of biocompatible hyaluronic acid (HA) as a delivery system of siRNA and antisense oligonucleotides. HA was modified with cationic polymer polyethylenimine (PEI). When compared with PEI alone, cationic PEI derivatives of HA (HA-PEI) provided increased cellular delivery of Small interfering RNA (siRNA) in B16F1, A549, HeLa, and Hep3B tumor cells. Indeed, more than 95% of the cells were positive for siRNA following its delivery with HA-PEI. A survivin-specific siRNA that was delivered using HA-PEI potently reduced the mRNA expression levels of the target gene in all of the cell lines. By contrast, survivin-specific siRNA delivered by PEI alone did not induce a significant reduction in mRNA levels. In green fluorescent protein (GFP)-expressing 293 T cells, a loss of GFP expression was evident in the cells that had been treated with GFP-specific siRNA and HA-PEI complex. The inhibition of target gene expression by antisense oligonucleotide G3139 was also enhanced after delivery with HA-PEI. Moreover, HA-PEI displayed lower cytotoxicity than PEI alone. These results suggest that HA-PEI could be further developed as biocompatible delivery systems of siRNA and antisense oligonucleotides for enhanced cellular uptake and inhibition of target gene expression.
Asunto(s)
Ácido Hialurónico/química , Oligonucleótidos Antisentido/administración & dosificación , ARN Interferente Pequeño/administración & dosificación , Animales , Cationes , Línea Celular Tumoral , Portadores de Fármacos , Proteínas Fluorescentes Verdes/química , Humanos , Espectroscopía de Resonancia Magnética , Oligonucleótidos Antisentido/farmacocinética , Oligonucleótidos Antisentido/farmacología , Polietileneimina/química , ARN Interferente Pequeño/farmacocinética , ARN Interferente Pequeño/farmacologíaRESUMEN
Most cationic liposomes used for gene delivery suffer from reduced transfection efficiency in the presence of serum. In this study, we report serum-enhanced delivery efficiency of siRNA via the use of newly synthesized liposomes that contain cationic lipids. Two cholesterol derivatives, cholesteryloxypropan-1-amine (COPA) and cholesteryl-2-aminoethylcarbamate (CAEC), were synthesized. A fluorescein label was then used to visualize cellular uptake of small interfering RNA (siRNA) via COPA or CAEC-based liposomes. The presence of serum had different effects on the cellular delivery of siRNA when siRNA was complexed to different cationic liposomes. CAEC-based liposomes showed significantly reduced cellular delivery of siRNA in serum-containing media as compared to serum-free media. Conversely, COPA-based liposomes (COPA-L) provided serum-enhanced delivery of siRNA in Hepa1-6, A549, and Hela cell lines. Following delivery of the oncogene survivin-specific siRNA, COPA-L reduced the mRNA expression levels of the target gene more efficiently than did Lipofectamine 2000. The delivery of green fluorescent protein-specific siRNA with COPA-L reduced the expression of green fluorescent protein in 293T stable cell lines. The apoptosis of Hepa1-6 significantly increased by delivery of survivin-specific siRNA by COPA-L. Additionally, Hepa1-6, A549, and Hela cells were >80% viable after treatment with COPA-L. These results suggest that the newly synthesized cholesterol derivative, COPA-L, could be further developed as a serum-enhanced delivery system of siRNA.
