Specific block of androgen receptor activity by antisense oligonucleotides.
Claims about molecular mechanisms underlying the resistance to anti-hormones of prostate cancer cells find support in biological experiments, which involve hormone-independent activation of the androgen receptor's (AR) transcriptional activity. In order to test this hypothesis, we attempted to shut down the expression of AR by the means of target-directed antisense oligonucleotides. A set of 49 oligonucleotides matching sequences of the AR mRNA either in the coding sequence or in the 3' and 5' untranslated regions were synthesized and examined in a cellular AR-dependent reporter system. Five antisense oligonucleotides were identified as highly potent inhibitors of AR-driven gene expression in a cellular reporter assay. These five were further profiled using point-mutated control sequences for the assessment of AR inhibition. In addition the expression of another AR-driven gene, the modulator of PSA expression (gene for inhibition of prostate specific antigen, an endogenous, AR-driven gene) was examined. Finally, we observed that the hormone-independent but AR-mediated transactivation by IGF-1 could also be specifically shut-down by these antisense oligonucleotides. The selection of highly target-restricted antisense oligonucleotides in the prostate cancer cell line LNCaP provided tools to study a central role of the androgen receptor in growth regulation of prostatic cancer cell lines and could be of utility in cancer situations in vivo.
Hamy
F
F
Novartis AG, Pharma Research, Oncology Department, Basel, Switzerland. francois.hamy@unibas.ch
Brondani
V
V
Spoerri
R
R
Rigo
S
S
Stamm
C
C
Klimkait
T
T
D059002:Androgen Receptor Antagonists; D000727:Androgen-Binding Protein / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology*; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics; D017430:Prostate-Specific Antigen / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000378:metabolism*; D051381:Rats; D011944:Receptors, Androgen / Q000187:drug effects* / Q000378:metabolism; D015533:Transcriptional Activation / Q000235:genetics*; D014162:Transfection; D014407:Tumor Cells, Cultured
D059002:Androgen Receptor Antagonists; D000727:Androgen-Binding Protein; D017931:DNA Primers; D016376:Oligonucleotides, Antisense; D011944:Receptors, Androgen; C027519:probasin; D007334:Insulin-Like Growth Factor I; D017430:Prostate-Specific Antigen