RESUMO
Liver tropism potentially leading to massive hepatocyte transduction and hepatotoxicity still represents a major drawback to adenovirus (Ad)-based gene therapy. We previously demonstrated that substitution of the hexon hypervariable region 5 (HVR5), the most abundant capsid protein, constituted a valuable platform for efficient Ad retargeting. The use of different mouse strains revealed that HVR5 substitution also led to dramatically less adenovirus liver transduction and associated toxicity, whereas HVR5-modified Ad were still able to transduce different cell lines efficiently, including primary hepatocytes. We showed that HVR5 modification did not significantly change Ad blood clearance or liver uptake at early times. However, we were able to link the lower liver transduction to enhanced HVR5-modified Ad liver clearance and impaired use of blood factors. Most importantly, HVR5-modified vectors continued to transduce tumors in vivo as efficiently as their wild-type counterparts. Taken together, our data provide a rationale for future design of retargeted vectors with a safer profile.
Assuntos
Adenoviridae/genética , Proteínas do Capsídeo/genética , Fígado/metabolismo , Alanina Transaminase/sangue , Animais , Carcinoma Pulmonar de Lewis/sangue , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/patologia , Linhagem Celular Tumoral , Vetores Genéticos/genética , Interleucina-6/sangue , Contagem de Leucócitos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Nus , Contagem de Plaquetas , Reação em Cadeia da Polimerase , Transdução Genética/métodosRESUMO
KiSS1 is a putative metastasis suppressor gene in melanoma and breast cancer-encoding kisspeptins, which are also described as neuroendocrine regulators of the gonadotropic axis. Negative as well as positive regulation of KiSS1 gene expression by estradiol (E(2)) has been reported in the hypothalamus. Estrogen receptor alpha (ERalpha level is recognized as a marker of breast cancer, raising the question of whether expression of KiSS1 and its G-protein-coupled receptor (GPR54) is down- or upregulated by estrogens in breast cancer cells. KiSS1 was found to be expressed in MDA-MB-231, MCF7, and T47D cell lines, but not in ZR75-1, L56Br, and MDA-MB-435 cells. KiSS1 mRNA levels decreased significantly in ERalpha-negative MDA-MB-231 cells expressing recombinant ERalpha. In contrast, tamoxifen (TAM) treatment of ERalpha-positive MCF7 and T47D cells increased KiSS1 and GPR54 levels. The clinical relevance of this negative regulation of KiSS1 and GPR54 by E(2) was then studied in postmenopausal breast cancers. KiSS1 mRNA increased with the grade of the breast tumors. ERalpha-positive invasive primary tumors expressed sevenfold lower KiSS1 levels than ERalpha-negative tumors. Among ERalpha-positive breast tumors from postmenopausal women treated with TAM, high KiSS1 combined with high GPR54 mRNA tumoral levels was unexpectedly associated with shorter relapse-free survival (RFS) relative to tumors expressing low tumoral mRNA levels of both genes. The contradictory observation of putative metastasis inhibitor role of kisspeptins and RFS to TAM treatment suggests that evaluation of KiSS1 and its receptor tumoral mRNA levels could be new interesting markers of the tumoral resistance to anti-estrogen treatment.
Assuntos
Neoplasias da Mama/diagnóstico , Carcinoma Ductal de Mama/diagnóstico , Neoplasias Hormônio-Dependentes/diagnóstico , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/farmacologia , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/terapia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/terapia , Intervalo Livre de Doença , Regulação para Baixo/efeitos dos fármacos , Estrogênios/farmacologia , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Kisspeptinas , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/genética , Neoplasias Hormônio-Dependentes/genética , Neoplasias Hormônio-Dependentes/metabolismo , Neoplasias Hormônio-Dependentes/terapia , Prognóstico , Receptores de Kisspeptina-1 , Tamoxifeno/farmacologia , Tamoxifeno/uso terapêutico , Células Tumorais CultivadasRESUMO
Fas and tumor necrosis factor receptor 1 (TNFR1) are death receptors involved in various diseases such as hepatitis, sepsis, or graft rejection. Neutralizing antibodies to death ligands or soluble death receptors can inhibit cell death; however, they induce side effects because of their systemic actions. To specifically block death signaling to target cells, we created death domain-deficient (DeltaDD) membrane-anchored receptors, delivered to the liver by either recombinant adenovirus or hydrodynamic pressure of nonviral recombinant plasmids. In anti-Fas antibody-induced fulminant hepatitis, mice expressing recombinant Fas-decoy receptors (FasDeltaDD) in their livers were completely protected against apoptosis and survived fulminant hepatitis. In T-cell-dependent concanavalin A-induced autoimmune hepatitis, FasDeltaDD antagonist expression prevented hepatocyte damage and mouse death. Finally, TNFR1DeltaDD effectively protected mice against LPS-induced septic shock. In conclusion, such DeltaDD-decoy receptors act as dominant-negative receptors exerting local inhibition, while avoiding systemic neutralization of apoptosis ligands, and might have therapeutic potential in hepatitis.
