RESUMO
The Tg.rasH2 mouse is a hemizygous transgenic mouse, approved by regulatory agencies for carcinogenicity assessment. However, the absence of a historical database for the incidence of spontaneous neoplasms has subsequently led to reluctance by some pharmaceutical companies to adopt the use of this short-term carcinogenicity assay. Our laboratory has generated a database summarizing the mortality, body weights, and the incidence of spontaneous tumors in 1420 male and female mice assigned to 26 studies conducted at our facility. In addition, we present the incidence of tumors in positive control mice treated with urethane from these studies. Mortality in the vehicle-treated Tg.rasH2 mouse was low (average of 1% in each study). The most common spontaneous tumors in the Tg.rasH2 mice were alveolar bronchiolar adenoma of the lungs (10.14% in males and 5.77% in females) and hemangiosarcoma of the spleen (3.66% in both males and females). The incidence of all other tumors was generally very low. In the positive control, urethane-treated animals, the incidence of alveolar bronchiolar adenomas and alveolar bronchiolar carcinomas in the lungs was 93.69% and 42.88% in males and 92.43% and 72.79% in females, respectively. In addition, the incidence of splenic hemangiosarcomas in urethane-treated males was 89.18% and 92.25% in females. The 6-month Tg.rasH2 assay is more precise, faster, and more economical than the conventional 2-year mouse assays because of the low incidence of background tumors, very high survival, shorter duration, and the lower number of animals used.
Assuntos
Adenocarcinoma Bronquioloalveolar/genética , Genes ras , Hemangiossarcoma/genética , Neoplasias Pulmonares/genética , Doenças dos Roedores/genética , Neoplasias Esplênicas/genética , Adenocarcinoma Bronquioloalveolar/veterinária , Animais , Grupos Controle , Bases de Dados Factuais , Feminino , Hemangiossarcoma/veterinária , Hemizigoto , Neoplasias Pulmonares/veterinária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Neoplasias Esplênicas/veterinária , Análise de Sobrevida , Uretana/toxicidadeRESUMO
Clinical gene transfer holds promise for the treatment of many inherited and acquired disorders. A key consideration for all clinical gene transfer applications is the tight control of transgene expression. We have examined the safety and biodistribution of a serotype 2, recombinant adeno-associated viral (AAV2) vector that encodes a rapamycin-responsive chimeric transcription factor, which regulates the expression of a therapeutic transgene (human erythropoietin [hEpo]). The vector, AAV2-TF2.3w-hEpo (2.5 × 10(7)-2.5 × 10(10) particles), was administered once to a single submandibular gland of male and female mice and mediated hEpo expression in vivo following a rapamycin injection but not in its absence. Control (saline treated) and vector-treated animals maintained their weight, and consumed food and water, similarly. Vector delivery led to no significant toxicological effects as judged by hematology, clinical chemistry, and gross and microscopic pathology evaluations. On day 3 after vector delivery, vector copies were not only abundant in the targeted right submandibular gland but also detected in multiple other tissues. Vector was cleared from the targeted gland much more rapidly in female mice than in male mice. Overall, our results are consistent with the notion that administration of the AAV2-TF2.3w-hEpo vector to salivary glands posed no significant risk in mice.
Assuntos
Dependovirus/genética , Técnicas de Transferência de Genes/efeitos adversos , Vetores Genéticos/administração & dosagem , Glândula Submandibular/virologia , Animais , Peso Corporal , Eritropoetina/sangue , Eritropoetina/genética , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Medição de Risco , Fatores Sexuais , Sirolimo/farmacologia , Glândula Submandibular/metabolismo , Testes de ToxicidadeRESUMO
Before conducting a phase 1/2 clinical trial of a serotype 5 adenovirus encoding human aquaporin-1 (AdhAQP1) for the treatment of radiation-damaged salivary glands, we have conducted a detailed toxicity and biodistribution study in adult rats. AdhAQP1 (2x108-2x1011 particles) was delivered to a single submandibular gland by retroductal cannulation. Administration of this vector resulted in no animal mortality or morbidities, and no adverse signs of clinical toxicity. In addition, over the 92-day time course of the study, with both male and female rats, there were no consistent treatment-related changes in serum indicators of hepatic, renal, and cardiac functions. Importantly, we also observed no vector-associated effects on either water consumption by, or hematocrit levels in, study animals. However, three suggestive mild gender-related response differences were seen. Female, but not male, rats exhibited small reductions in food consumption (10-15%) and body weight gain (5-10%), and evidence of persistent inflammation, after vector treatment. These were vector, but not dose, related. Three days after delivery of 2x1011 particles of AdhAQP1, vector was detected primarily in the targeted gland; 9 of 10 samples from the targeted gland were positive, whereas only 5 of 90 nonoral samples were positive. There was no evidence of the generation of replication-competent adenovirus in saliva or blood samples. In aggregate, these findings show that localized delivery of AdhAQP1 to salivary glands appears to occur without significant toxicity.
