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Status |
Public on Mar 30, 2012 |
Title |
Unique signatures of estrogen independent growth of MCF-7 cells in low-estrogen versus complete estrogen depravation |
Organism |
Homo sapiens |
Experiment type |
Expression profiling by array
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Summary |
Despite the success of the aromatase inhibitors (AIs) in treating estrogen receptor positive breast cancer, 15-20% of patients receiving adjuvant AIs will relapse within 5-10 years of treatment initiation. Long term estrogen deprivation (LTED) of breast cancer cells in culture has been successfully used to mimic AI-induced estrogen depletion to dissect mechanisms of AI resistance. However, we hypothesized that a subset of patients receiving AI therapy may maintain low circulating concentrations of estrogens that influence the development of endocrine resistance. We sought to expand established LTED models to account for these observations. MCF-7 cells were grown in medium with charcoal stripped serum supplemented with defined concentrations of E2 or the estrogenic androgen metabolite 3βAdiol. Cells were selected in the EC10 and EC90 of E2 or 3βAdiol, or estrogen deprived. Estrogen-independence was evaluated during selection by assessing cell growth in the absence or presence of E2 or 3βAdiol. Following >7 months of selection, estrogen-independence developed in estrogen-deprived cells and cells maintained in low concentrations of steroid hormone. Functional analyses demonstrated that estrogen-deprived and low-steroid selected cells developed estrogen-independence via unique mechanisms, independent and dependent of ERα, respectively. Estrogen-independent growth in low-steroid selected cells could be blocked by kinase inhibitors. However, these cells were completely resistant to kinase inhibition in the presence of low steroid hormone concentrations. These data offer a novel perspective on the development of resistance to AI therapy, and may yield novel approaches to treat AI-resistant tumors.
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Overall design |
MCF-7 cells were selected for >7months in IMEM+10% Charcoal Stripped FBS, supplmented with defined steroid hormone conditions. Following outgrowth of estrogen-independent cells, cell lines were grown in estrogen-free conditions and gene expression analysis was performed to identify drivers of estrogen-independent growth. Cells were assessed in biological triplicates.
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Contributor(s) |
Sikora MJ, Strumba V, Lippman ME, Johnson MD, Rae JM |
Citation(s) |
22456984 |
Submission date |
Oct 27, 2011 |
Last update date |
Aug 13, 2018 |
Contact name |
Viktoriya Strumba |
Organization name |
University of Michigan
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Street address |
109 Zina Pitcher place
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City |
Ann Arbor |
State/province |
MI |
ZIP/Postal code |
48109 |
Country |
USA |
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Platforms (1) |
GPL10558 |
Illumina HumanHT-12 V4.0 expression beadchip |
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Samples (15)
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Relations |
BioProject |
PRJNA149285 |