Project description:The crucial role of androgen receptor in prostate cancer development is well documented, and its inhibition is a mainstay of prostate cancer treatment. Here we analyze the perturbations to the androgen receptor cistrome caused by a minor groove binding molecule that is designed to target a sequence found in a subset of androgen response elements. We find treatment with this pyrrole-imidazole polyamide exhibits sequence selectively in its repression of androgen receptor binding in vivo. Differentially changed loci are enriched for sequences resembling ARE half-sites that match the Py-Im polyamide binding preferences determined in vitro. Comparatively, permutations of ARE half-site bearing single or double mismatches to the Py-Im polyamide binding sequence are not enriched. This study represents an indirect determination of Py-Im polyamide binding preference in vivo using an unbiased approach.
Project description:Gene regulation by DNA binding small molecules could have important therapeutic applications. This study reports the investigation of a DNA-binding pyrrole-imidazole polyamide targeted to bind the DNA sequence 5’-WGGWWW-3’ with reference to its potency in a subcutaneous xenograft tumor model. The molecule is capable of trafficking to the tumor site following subcutaneous injection and modulates transcription of select genes in vivo. A FITC-labeled analogue of this polyamide can be detected in tumor-derived cells by confocal microscopy. RNA deep sequencing (RNA-seq) of tumor tissue allowed the identification of further affected genes, a representative panel of which were interrogated by qRT-PCR and correlated with cell culture expression levels.
Project description:Gene regulation by DNA binding small molecules could have important therapeutic applications. This study reports the investigation of a DNA-binding pyrrole-imidazole polyamide targeted to bind the DNA sequence 5M-bM-^@M-^Y-WGGWWW-3M-bM-^@M-^Y with reference to its potency in a subcutaneous xenograft tumor model. The molecule is capable of trafficking to the tumor site following subcutaneous injection and modulates transcription of select genes in vivo. A FITC-labeled analogue of this polyamide can be detected in tumor-derived cells by confocal microscopy. RNA deep sequencing (RNA-seq) of tumor tissue allowed the identification of further affected genes, a representative panel of which were interrogated by qRT-PCR and correlated with cell culture expression levels. Xenografts. Grafting with A549-luc-C8. Experiments were performed in female SCID-beige mice (Charles River) between 8 and 12 weeks of age. Cells were injected into the left flank area of the animals as suspensions of 25 x 106 mL-1 in RPMI, 200 M-BM-5L per injection. Treatment and tumor proliferation monitoring. Mice were treated following the schedule delineated in treatment protocol. Tumor proliferation was monitored using the XENOGEN imaging device. The animals were anesthetized with 2 5 % isoflurane and subsequently transferred to the imaging chamber, whereupon the isoflurane levels were reduced to 1-2.5 %. The floor of the imager was heated to +37 M-BM-:C to avoid hypothermia. Breathing frequency was monitored and not allowed to drop below 1 s-1, adjusting the isoflurane levels accordingly at all times. Endpoint criteria and euthanasia. Animal endpoint criteria encompassed weight loss of over 15 %, restriction of motor function by the engrafted tumor, dehydration of over 10 % and moribund behavior. Where appropriate, the animals were euthanized by asphyxiation in a CO2 chamber. Tumor tissue harvest. Animals were resected and tumors excised using standard forceps, scissors and surgical blades. The tumors were combined into one sample per condition and mechanically sheared in TRIZOL, employing a specialized device (tissue tearer, model 985370). Total RNA workup was performed following the standard TRIZOL procedure, followed by a DNAse digest.
Project description:We report that a DNA minor groove binding hairpin pyrrole-imidazole (Py-Im) polyamide interferes with RNA polymerase II (RNAP2) activity in cell culture. Genome-wide mapping of RNAP2 binding shows reduction of occupancy preferentially at transcription start sites (TSS), while occupancy at enhancer sites are is unchanged. Genome-wide mapping of RNA polymerase II in LNCaP cells treated with DHT and DHT with Py-Im polyamide.
Project description:We report that a DNA minor groove binding hairpin pyrrole-imidazole (Py-Im) polyamide interferes with RNA polymerase II (RNAP2) activity in cell culture. Genome-wide mapping of RNAP2 binding shows reduction of occupancy preferentially at transcription start sites (TSS), while occupancy at enhancer sites are is unchanged.