Ad-mTERT-Δ19, a Conditional Replication-Competent Adenovirus Driven by the Human Telomerase Promoter, Selectively Replicates in and Elicits Cytopathic Effect in a Cancer Cell-Specific Manner
Autor: | Chae-Ok Yun, Ha Youn Shin, Joohyuk Sohn, Jungho Kim, Joo Hang Kim, Hansaem Lee, Eun Hee Kim, Jai Myung Yang, Hoguen Kim |
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Rok vydání: | 2003 |
Předmět: |
Telomerase
Time Factors Transcription Genetic cells Tetrazolium Salts medicine.disease_cause Mice Genes Reporter Coloring Agents Promoter Regions Genetic Gene Transfer Techniques Up-Regulation Lac Operon embryonic structures Molecular Medicine biological phenomena cell phenomena and immunity Oncolytic adenovirus Sp1 Transcription Factor Blotting Western Genetic Vectors Molecular Sequence Data Mice Nude Antineoplastic Agents Biology Adenoviridae Proto-Oncogene Proteins c-myc Cell Line Tumor Genetics medicine Animals Humans Telomerase reverse transcriptase neoplasms Molecular Biology Base Sequence Models Genetic Neoplasms Experimental beta-Galactosidase Telomere Thiazoles enzymes and coenzymes (carbohydrates) Gene Expression Regulation Viral replication Cell culture Cancer cell Cancer research Neoplasm Transplantation HeLa Cells |
Zdroj: | Human Gene Therapy. 14:1415-1428 |
ISSN: | 1557-7422 1043-0342 |
Popis: | Human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase, functions to stabilize telomere length during chromosomal replication. Previous studies have shown that hTERT promoter is highly active in most tumor and immortal cell lines but inactive in normal somatic cell types. The use of wild-type hTERT promoter, however, may be limited by its inability to direct high level and cancer cell-specific expression necessary for effective targeted gene therapy. To improve cancer cell specificity and the strength of the hTERT promoter, a modified hTERT, m-hTERT promoter was generated in which additional copies of c-Myc and Sp1 binding sites were incorporated adjacent to the promoter. As assessed using relative lacZ expression, hTERT and m-hTERT promoter activity was significantly upregulated in cancer cells but not in normal cells, and within these upregulated cancer cells, m-hTERT promoter strength was substantially higher than that of the wild-type hTERT. Next, to restrict viral replication to tumor cells, a conditional replication-competent adenoviruses, Ad-TERT-Delta19 and Ad-mTERT-delta19 were generated in which the E1A gene, which is essential for viral replication, was placed under the control of the hTERT and m-hTERT promoter, respectively. While the wild-type Ad-TERT-delta19 replicated in and induced cytopathic effect in cancer and in some normal cell lines, Ad-mTERT-delta19 enhanced viral replication and cytopathic effect only in cancer cells. Furthermore, the growth of established human cervical carcinoma in nude mice was significantly suppressed by intratumoral injection of Ad-mTERT-delta19. Taken together, present results strongly suggest that the use of the m-hTERT promoter is not only useful in the regulation of therapeutic gene expression but also that replication-competent oncolytic adenovirus under the control of the m-hTERT promoter may be a new promising tool for the treatment of human malignancies. |
Databáze: | OpenAIRE |
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