RESUMO
We have examined the effect of adenoviruses expressing soluble transforming growth factor receptorII-Fc (sTGFßRIIFc) in a 4T1 mouse mammary tumor bone metastasis model using syngeneic BALB/c mice. Infection of 4T1 cells with a non-replicating adenovirus, Ad(E1-).sTßRFc, or with two oncolytic adenoviruses, Ad.sTßRFc and TAd.sTßRFc, expressing sTGFßRIIFc (the human TERT promoter drives viral replication in TAd.sTßRFc) produced sTGFßRIIFc protein. Oncolytic adenoviruses produced viral replication and induced cytotoxicity in 4T1 cells. 4T1 cells were resistant to the cytotoxic effects of TGFß-1 (up to 10 ng ml(-1)). However, TGFß-1 induced the phosphorylation of SMAD2 and SMAD3, which were inhibited by co-incubation with sTGFßRIIFc protein. TGFß-1 also induced interleukin-11, a well-known osteolytic factor. Intracardiac injection of 4T1-luc2 cells produced bone metastases by day 4. Intravenous injection of Ad.sTßRFc (on days 5 and 7) followed by bioluminescence imaging (BLI) of mice on days 7, 11 and 14 in tumor-bearing mice indicated inhibition of bone metastasis progression (P<0.05). X-ray radiography of mice on day 14 showed a significant reduction of the lesion size by Ad.sTßRFc (P<0.01) and TAd.sTßRFc (P<0.05). Replication-deficient virus Ad(E1-).sTßRFc expressing sTGFßRIIFc showed some inhibition of bone metastasis, whereas Ad(E1-).Null was not effective in inhibiting bone metastases. Thus, systemic administration of Ad.sTßRFc and TAd.sTßRFc can inhibit bone metastasis in the 4T1 mouse mammary tumor model, and can be developed as potential anti-tumor agents for breast cancer.
Assuntos
Adenoviridae/metabolismo , Neoplasias Ósseas/terapia , Neoplasias Mamárias Experimentais/terapia , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Adenoviridae/genética , Adenoviridae/fisiologia , Administração Intravenosa , Animais , Neoplasias Ósseas/secundário , Linhagem Celular Tumoral , Feminino , Humanos , Imunocompetência , Medições Luminescentes/métodos , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos/genética , Vírus Oncolíticos/metabolismo , Vírus Oncolíticos/fisiologia , Fosforilação , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases/genética , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Transdução de Sinais , Proteína Smad2/genética , Proteína Smad2/metabolismo , Telomerase/genética , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Transplante Isogênico/métodos , Ensaio Tumoral de Célula-Tronco/métodos , Replicação ViralRESUMO
We were interested in developing oncolytic adenoviral vectors that can be administered systemically for the treatment of breast cancer. To restrict viral replication in breast tumor cells, we constructed mhTERTAd.sTbetaRFc, a 01/07-based adenoviral vector expressing the soluble form of transforming growth factor-beta (TGFbeta) receptor II fused with the human Fc IgG1 (sTGFbetaRIIFc) gene, in which viral replication is under the control of a modified human telomerase reverse transcriptase (mhTERT) promoter. In addition, mhTERTAd.sTbetaRFc-mediated sTGFbetaRIIFc production targets the TGFbeta pathway known to contribute to the tumor progression of breast cancer metastasis. We chose to use the mhTERT promoter because it was found to be relatively more active (approximately 20 times) in breast cancer cells compared with normal human cells. We showed that infection of MDA-MB-231 and MCF-7 breast cancer cells for 48 h with mhTERTAd.sTbetaRFc produced high levels of sTGFbetaRIIFc (greater than 1 microg ml(-1)) in the medium. Breast cancer cells produced nearly a 6000-fold increase in viral titers during the 48 h infection period. However, mhTERTAd.sTbetaRFc replication was attenuated in normal cells. Infection of breast cancer cells with a replication-deficient virus Ad(E1(-)).sTbetaRFc also produced high levels of sTGFbetaRIIFc, but under these conditions, no detectable viral replication was observed. Adenoviral-mediated production of sTGFbetaRIIFc was shown to bind with TGFbeta-1, and to abolish the effects of TGFbeta-1 on downstream SMAD-3 phosphorylation. The administration of mhTERTAd.sTbetaRFc intravenously into MDA-MB-231 human xenograft-bearing mice resulted in a significant inhibition of tumor growth and production of sTGFbetaRIIFc in the blood. Conversely, intravenous injection of Ad(E1(-)).sTbetaRFc did not show a significant inhibition of tumor growth, but resulted in sTGFbetaRIIFc in the blood, suggesting that viral replication along with sTGFbetaRIIFc protein production is critical in inducing the inhibition of tumor growth. These results warrant future investigation of mhTERTAd.sTbetaRFc as an antitumor agent in vivo.
Assuntos
Adenoviridae/fisiologia , Neoplasias da Mama/terapia , Terapia Viral Oncolítica , Regiões Promotoras Genéticas/genética , Telomerase/genética , Fator de Crescimento Transformador beta/antagonistas & inibidores , Replicação Viral , Infecções por Adenoviridae/genética , Infecções por Adenoviridae/terapia , Infecções por Adenoviridae/virologia , Animais , Western Blotting , Neoplasias da Mama/genética , Neoplasias da Mama/virologia , Linhagem Celular Tumoral , Efeito Citopatogênico Viral , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação Neoplásica da Expressão Gênica , Vetores Genéticos , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Camundongos , Camundongos Nus , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Transdução de Sinais , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Two cases are presented in which a serious contrast reaction was accompanied by a dense persistent nephrogram. This radiologic sign results from the patient's systemic hypotension and provides the physician with an opportunity for earlier, more effective therapy.
