RRC ID 30915
Author Kurayoshi K, Ozono E, Iwanaga R, Bradford AP, Komori H, Ohtani K.
Title Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs.
Journal Biochem Biophys Res Commun
Abstract In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter is activated by E2F only in cancer cells and therefore may be more cancer cell-specific than E2F1 promoter to drive gene expression. We show here that the ARF promoter has lower activity in normal growing fibroblasts and shows higher cancer cell-specificity compared to the E2F1 promoter. We also demonstrate that adenovirus expressing HSV-TK under the control of the ARF promoter shows lower cytotoxicity than that of the E2F1 promoter, in normal growing fibroblasts but has equivalent cytotoxicity in cancer cell lines. These results suggest that the ARF promoter, which is specifically activated by deregulated E2F activity, is an excellent candidate to drive therapeutic cytotoxic gene expression, specifically in cancer cells.
Volume 450(1)
Pages 240-6
Published 2014-7-18
DOI 10.1016/j.bbrc.2014.05.102
PII S0006-291X(14)00991-7
Description 細胞毒性を持つHSV-TK遺伝子をがん細胞特異的に発現させるため、本プラスミドの HSV-TK 遺伝子をAFRプロモーター下流にサブクローニングし、さらにアデノウイルスに組み込んで使用しています。また、コントロールとしてE2F1プロモーター下流にもHSV-TK 遺伝子をサブクローニングして使用しています。
PMID 24893334
MeSH Apoptosis / genetics Cell Line, Tumor E2F1 Transcription Factor / genetics* Genes, Transgenic, Suicide / genetics Genes, Tumor Suppressor Genetic Therapy / methods Humans Neoplasms, Experimental / genetics* Neoplasms, Experimental / therapy* Promoter Regions, Genetic / genetics* Tumor Suppressor Protein p14ARF / genetics* Tumor Suppressor Proteins / genetics*
IF 2.985
Times Cited 5
DNA material pTK5 (RDB01027)