Targeted gene expression using a 1.1 kilobase promoter fragment of the tumour-associated antigen EpCAM.
The epithelial cell adhesion molecule EpCAM is over- or de novo expressed during carcinogenesis. EpCAM expression correlates with increased proliferation and dedifferentiation. Recently, we reported the cloning of a 1.1 kilobase fragment upstream of the epcam gene and demonstrated its specific transcriptional activity. Here, we analyzed the potential of this fragment for targeted gene expression. The fragment was used to regulate the expression of the green fluorescent protein (GFP) and HSV-1 thymidine kinase (HSV-TK), as a model therapeutic gene. Transfection of the pEpProm-control or pEpProm-GFP plasmids resulted in the expression of functional GFP and HSV-TK proteins specifically in EpCAM-positive cells. Expression levels of both proteins correlated with the amount of EpCAM. Additionally, the targeted expression of HSV1-TK transferred a marked sensitivity to ganciclovir treatment in EpCAM-positive HEK293-EBNA1 and SkBr3 carcinoma cells. The EpCAM promoter fragment is, thus, a novel tool to allow for the transcription of therapeutic genes, specifically, in EpCAM-positive carcinomas.
Gires
Olivier
O
Department of Otorhinolaryngology, Head and Neck Surgery, Grosshadern Medical Center, Ludwig-Maximilians-University of Munich, Marchioninistr. 15, 81377 Munich, Germany. ogires@hno.med.uni-muenchen.de
Pöckl
Stephanie
S
Chapman
Rob D
RD
Münz
Markus
M
D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D015815:Cell Adhesion Molecules / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D000071858:Epithelial Cell Adhesion Molecule; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics; D015774:Ganciclovir / Q000493:pharmacokinetics / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000235:genetics*; D015316:Genetic Therapy; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics*; D018259:Herpesvirus 1, Human / Q000201:enzymology / Q000235:genetics; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics; D013937:Thymidine Kinase / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D014162:Transfection
D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D000071858:Epithelial Cell Adhesion Molecule; D019309:Epstein-Barr Virus Nuclear Antigens; D049452:Green Fluorescent Proteins; D013937:Thymidine Kinase; C417029:EBV-encoded nuclear antigen 1; D015774:Ganciclovir