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Androgen and Glucocorticoid stimulation of LREX' cells in vitro

ABSTRACT: The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Using the LnCaP/AR xenograft model, we identified induction of glucocorticoid receptor (GR) expression as a common feature of drug resistant tumors. From a resistant xenograft tumor, we derived a GR expressing resistant subline called LREX. In this model, activation of GR and AR activate a similar but distinguishable set of target genes. LREX' cells were cultured in steroid depleted media and then treated for 8 hours with the indicated drugs in biological triplicates.

ORGANISM(S): Homo sapiens

SUBMITTER: Vivek Arora

PROVIDER: E-GEOD-51871 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Glucocorticoid receptor confers resistance to antiandrogens by bypassing androgen receptor blockade.

Arora Vivek K VK Schenkein Emily E Murali Rajmohan R Subudhi Sumit K SK Wongvipat John J Balbas Minna D MD Shah Neel N Cai Ling L Efstathiou Eleni E Logothetis Chris C Zheng Deyou D Sawyers Charles L CL

Cell 20131201 6

The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Here, we identify induction of glucocorticoid receptor (GR) expression as a common feature of drug-resistant tumors in a credentialed preclinical model, a finding also confirmed in patient samples. GR substituted for the androgen receptor (AR) to activate a similar but distinguishable set of target genes and was necessary for maintenance of the resistant phenotype. The GR agonist ...[more]

PMID: 24315100

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Project description:The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Using the LnCaP/AR xenograft model, we identified induction of glucocorticoid receptor (GR) expression as a common feature of drug resistant tumors. From a resistant xenograft tumor, we derived a GR expressing resistant subline called LREX' which maintains the resistant phenotype. mRNA expression was used to characterize resistant tissues. LnCaP/AR cells were injected into castrate mice and tumors were established. Mice were then treated with vehicle (Con), 4 days of anti-androgen (ARN-509 10mgkg), or were maintained on anti-androgen (10mg/kg ARN-509 or enzalutamide) until emergence of resistance. Resistant tissues continued to be exposed to anti-androgen through time of harvest. LREX' (LnCaP/AR Resistant to Enzalutamide Xenograft Derived) was derived from an enzalutamide resistant xenograft and was re-injected into castrate mice undergoing continual treatment with enzalutamide. The GR probe on the Illumina array failed to detect GR expression. Therefore, GR expression as determined by qPCR is annotated separately. Of the 10 control tissues, 8 were analyzed twice (technical duplicates annotated as A and B).

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