Malignant glioma is the most frequent type in brain tumors. The prognosis of this tumor has not been significantly improved for the past decades and the average survival of patients is less than one year. Thus, an effective novel therapy is urgently needed. TNF-related apoptosis inducing ligand (TRAIL), known to have tumor cell-specific killing activity, has been investigated as a novel therapeutic for cancers. We have developed Ad-stTRAIL, an adenovirus delivering secretable trimeric TRAIL for gene therapy and demonstrated the potential to treat malignant gliomas. Currently, this Ad-stTRAIL gene therapy is under phase I clinical trial for malignant gliomas. Here, we report preclinical studies for Ad-stTRAIL carried out using rats. We delivered Ad-stTRAIL intracranially and determined its pharmacokinetics and biodistribution. Most Ad-stTRAIL remained in the delivered site and the relatively low number of viral genomes was detected in the opposite site of brain and cerebrospinal fluid. Similarly, only small portion of the viral particles injected was found in the blood plasma and major organs and tissues, probably due to the brain-blood barrier. Multiple administrations did not lead to accumulation of Ad-stTRAIL at the injection site and organs. Repeated delivery of Ad-stTRAIL did not show any serious side effects. Our data indicate that intracranially delivered Ad-stTRAIL is a safe approach, demonstrating the potential as a novel therapy for treating gliomas.
Adenoviridae/genetics ; Animals ; Blood-Brain Barrier ; Brain/drug effects/*metabolism/pathology ; Brain Neoplasms/genetics/metabolism/pathology/*therapy ; Clinical Trials, Phase I as Topic ; DNA, Viral/metabolism ; Disease Models, Animal ; Drug Delivery Systems ; Drug Evaluation, Preclinical ; *Gene Therapy ; Glioma/genetics/metabolism/pathology/*therapy ; Humans ; Liver/drug effects/metabolism/pathology ; Protein Multimerization/genetics ; Rats ; Spleen/drug effects/metabolism/pathology ; TNF-Related Apoptosis-Inducing Ligand/genetics/*pharmacokinetics

Malignant glioma is the most frequent type in brain tumors. The prognosis of this tumor has not been significantly improved for the past decades and the average survival of patients is less than one year. Thus, an effective novel therapy is urgently needed. TNF-related apoptosis inducing ligand (TRAIL), known to have tumor cell-specific killing activity, has been investigated as a novel therapeutic for cancers. We have developed Ad-stTRAIL, an adenovirus delivering secretable trimeric TRAIL for gene therapy and demonstrated the potential to treat malignant gliomas. Currently, this Ad-stTRAIL gene therapy is under phase I clinical trial for malignant gliomas. Here, we report preclinical studies for Ad-stTRAIL carried out using rats. We delivered Ad-stTRAIL intracranially and determined its pharmacokinetics and biodistribution. Most Ad-stTRAIL remained in the delivered site and the relatively low number of viral genomes was detected in the opposite site of brain and cerebrospinal fluid. Similarly, only small portion of the viral particles injected was found in the blood plasma and major organs and tissues, probably due to the brain-blood barrier. Multiple administrations did not lead to accumulation of Ad-stTRAIL at the injection site and organs. Repeated delivery of Ad-stTRAIL did not show any serious side effects. Our data indicate that intracranially delivered Ad-stTRAIL is a safe approach, demonstrating the potential as a novel therapy for treating gliomas.
Adenoviridae/genetics ; Animals ; Blood-Brain Barrier ; Brain/drug effects/*metabolism/pathology ; Brain Neoplasms/genetics/metabolism/pathology/*therapy ; Clinical Trials, Phase I as Topic ; DNA, Viral/metabolism ; Disease Models, Animal ; Drug Delivery Systems ; Drug Evaluation, Preclinical ; *Gene Therapy ; Glioma/genetics/metabolism/pathology/*therapy ; Humans ; Liver/drug effects/metabolism/pathology ; Protein Multimerization/genetics ; Rats ; Spleen/drug effects/metabolism/pathology ; TNF-Related Apoptosis-Inducing Ligand/genetics/*pharmacokinetics

Interleukin 12 (IL-12), a heterodimeric cytokine, promotes an effective antitumor response against tumors of various histological types when delivered systemically as a protein or locally by gene transfer. We investigated parameters that influenced the effectiveness of IL-12 retroviral-mediated gene therapy of cancer in animals using the murine breast cancer line TS/A. Syngeneic fibroblasts (TIB80), stably transduced with a retrovirus expressing murine IL-12, were used for peritumoral injection. Injection of fibroblasts into established tumors resulted in complete regression of tumor in 40 % of animals in a dose dependent manner when treated on day 4, and 20 % when treated on day 8. Significant inhibition of growth of day 21 and day 40 tumors was observed following peritumoral injection of IL-12-expressing fibroblasts in a dose-dependent manner. Delivery of IL-12 by syngeneic fibroblasts at a tumor site is effective in eradicating established, weakly immunogenic TS/A tumors.
Animals ; Breast Neoplasms ; Fibroblasts ; Genetic Therapy* ; Interleukin-12* ; Retroviridae