Decoy androgen-responsive element DNA can inhibit androgen receptor transactivation of the PSA promoter gene.
Chemotherapy, hormonal therapy, or surgery may cause devastating toxic or other side effects. Androgen receptors (ARs) in the cytoplasm are activated by binding with androgen. Androgen-activated ARs bind to a specific genomic DNA sequence, the androgen-responsive element (ARE), and initiate gene expression at the transcriptional level. Even without androgen activation, ARs may have a role in androgen-refractory prostate cancer. Thus, inhibition of AR activity may have therapeutic value. We applied a genetic reporter of the Dual-Luciferase Assay System to test whether a short double-stranded genomic DNA containing prostate-specific antigen (PSA) ARE sequence as decoy DNA would inhibit the function of activated AR. A 21-mer phosphorothioated PSA ARE decoy DNA was synthesized, with a plasmid vector containing the PSA promoter upstream from a luciferase gene, the reporter gene. The promoter and reporter were co-transfected into a human prostate cancer cell line PC3-M with the aid of Lipofectamin 2000. After 24 hr exposure to androgens, the cells were lysed and luciferase activity measured to determine the ARE decoy inhibitory effect on the function of ARs. Luciferase activity was reduced significantly in the ARE decoy transfected cells but not with inactive control decoy. The results demonstrate that ARE decoy DNA can effectively suppress androgen-activated ARs in prostate cancer cells and indicate the potential utility of decoy DNA for developing a novel therapy for prostate cancer.
Zhang
Pengju
P
Institute of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan 250012, People's Republic of China.
Zhang
Jianye
J
Young
Charles Y F
CY
Kao
Pai C
PC
Chen
Weiwen
W
Jiang
Anli
A
Zhang
Lianying
L
Guo
Qiang
Q
D059002:Androgen Receptor Antagonists; D045744:Cell Line, Tumor; D017930:Genes, Reporter; D006801:Humans; D008297:Male; D011401:Promoter Regions, Genetic / Q000235:genetics*; D017430:Prostate-Specific Antigen / Q000235:genetics*; D011944:Receptors, Androgen / Q000378:metabolism*; D020218:Response Elements / Q000235:genetics*; D013739:Testosterone / Q000494:pharmacology; D015533:Transcriptional Activation; D014162:Transfection
D059002:Androgen Receptor Antagonists; D011944:Receptors, Androgen; D013739:Testosterone; D017430:Prostate-Specific Antigen