RESUMO
Tumor-specific enhancer/promoter is applicable for targeting gene expression in tumors and helpful for tumor-targeting imaging and therapy. We aimed to acquire α-fetoprotein (AFP)-producing hepatocellular carcinoma (HCC) specific images using adenovirus containing HSV1-tk gene controlled by AFP enhancer/promoter and evaluate in vivo ganciclovir (GCV)-medicated therapeutic effects on AFP-targeted HSV1-tk expression with (18)F-FDG positron emission tomography (PET). Recombinant adenovirus expressing HSV1-tk under AFP enhancer/promoter was produced (AdAFP-TK) and the expression levels were evaluated by RT-PCR and (125)I-IVDU uptake. GCV-mediated HSV1-tk cytotoxicity was determined by MTT assay. After the mixture of AdAFP-fLuc and AdAFP-TK was administrated, bioluminescent images (BLIs) and (18)F-FHBG PET images were obtained in tumor-bearing mice. In vivo therapeutic effects of AdAFP-TK and GCV in the HuH-7 xenograft model were monitored by (18)F-FDG PET. When infected with AdAFP-TK, cell viability in HuH-7 was reduced, but those in HT-29 and SK-Hep-1 were not significantly decreased at any GCV concentration less than 100 µM. AFP-targeted fLuc and HSV1-tk expression were clearly visualized by BLI and (18)F-FHBG PET images in AFP-producing HCC, respectively. In vivo GCV-mediated tumor growth inhibition by AFP-targeted HSV1-tk expression was monitored by (18)F-FDG PET. Recombinant AdAFP-TK could be applied for AFP-targeted HCC gene therapy and imaging in AFP-producing HCC.
Assuntos
Carcinoma Hepatocelular/genética , Herpesvirus Humano 1/enzimologia , Neoplasias Hepáticas/metabolismo , Timidina Quinase/biossíntese , alfa-Fetoproteínas/biossíntese , Animais , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/virologia , Linhagem Celular Tumoral , Feminino , Células HT29 , Células Hep G2 , Herpesvirus Humano 1/genética , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/virologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Tomografia por Emissão de Pósitrons , Regiões Promotoras Genéticas , Timidina Quinase/genética , Timidina Quinase/metabolismo , alfa-Fetoproteínas/genéticaRESUMO
Lentiviral vector containing the HSV1-tk and firefly luciferase (fLuc) gene was infected into C6 and C6-TL expressing HSV1-tk and fLuc gene was generated. C6-TL showed higher [(125)I]IVDU uptake than C6. The survival rate of C6-TL decreased more rapidly with increasing GCV dose and was well correlated with fLuc activity. The images of microPET clearly demonstrated higher uptake of [(18)F]FHBG into the C6-TL tumor. Inhibition of tumor growth was observed in C6-TL tumor-bearing mice treated with GCV through tumor size measurement and bioluminescence imaging. The therapeutic effect of HSV1-tk/GCV system can be monitored using bioluminescent imaging and tumor size measurement.
Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/terapia , Ganciclovir/farmacologia , Genes Transgênicos Suicidas , Terapia Genética/métodos , Glioblastoma/terapia , Herpesvirus Humano 1/enzimologia , Medições Luminescentes , Timidina Quinase/biossíntese , Animais , Neoplasias Encefálicas/enzimologia , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Ganciclovir/metabolismo , Genes Reporter , Vetores Genéticos/genética , Glioblastoma/enzimologia , Glioblastoma/genética , Herpesvirus Humano 1/genética , Idoxuridina/análogos & derivados , Idoxuridina/metabolismo , Cinética , Lentivirus/genética , Luciferases de Vaga-Lume/biossíntese , Luciferases de Vaga-Lume/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Tomografia por Emissão de Pósitrons , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Timidina Quinase/genética , Carga Tumoral/efeitos dos fármacosRESUMO
Continuous irradiation with exponentially reducing beta-rays induces cell death, known as apoptosis. The aim of this study was to investigate the G2 arrest and apoptosis caused by the beta-ray emitted by the radioisotope (188)Re. Doses of 0.4 Gy (3.7 MBq), 4 Gy (37 MBq), and 40 Gy (370 MBq), were added to Blymphoma Raji cells, and cell viability, apoptosis, and DNA cell-cycle changes were assayed. (188)Re showed time- and dose-dependent effects on cell viability and on cell apoptosis and necrosis. At a (188)Re dose of 0.4 Gy, G(2) cell-cycle arrest was observed after 16 hours, and 4,6-diamidino-2-phenylindole (DAPI) staining indicated a slow, time-dependent increase in apoptotic bodies. At a (188)Re dose of 40 Gy, DNA fragmentation was observed at 2 hours, indicative of early damage in the nucleus. In summary, our results showed that continuous irradiation with low-dose beta-rays induced G(2) arrest and progressive apoptosis, which may be characteristic mechanisms of radionuclide therapy.