Transcription profiling of human breast cancer patients treated with Letrozole (Femara) early response to treatment
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ABSTRACT: Tumorigenic breast cancer cells characterized by high CD44 and low or undetectable CD24 levels (CD44+/CD24-/low) may be resistant to conventional therapies and responsible for cancer relapse. We defined a âsignatureâ expression pattern of hundreds of genes associated with CD44+/CD24-/low, mammosphere-forming cells. In a panel of patient breast tumors, this tumorigenic gene signature was found exclusively manifested in tumors of the recently identified âclaudin-lowâ molecular profile subtype characterized by overexpression of many mesenchymal-associated genes, suggesting that these tumors have pre-existing higher levels of tumorigenic cells. Furthermore, when comparing the expression profiles of paired breast cancer core biopsies before versus after hormone therapy or chemotherapy, both the tumorigenic and âclaudin-lowâ signatures were more active in about half of tumors after treatment, indicative of a greater enrichment of tumorigenic cells as a result of treatments targeting the bulk tumor cells. Experiment Overall Design: Biopsies were taken from the same subjects both pretreatment and after 10-14 days Letrozol, 2.5 mg/day, oral.
ORGANISM(S): Homo sapiens
SUBMITTER: Chad Creighton
PROVIDER: E-GEOD-10281 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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