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Gene expression of primary breast cancers from patients before and after neo-adjuvant Tamoxifen treatment

ABSTRACT: Tumor gene expression data (microarray from FFPE) was obtained from breast cancer patients enrolled in a pre-operative window trial (ClinicalTrials.gov Identifier: NCT00738777). Patients received an oral loading dose of 40 mg of tamoxifen twice daily for the first seven days, followed by a daily dose of 20 mg until surgery. A core needle biopsy of the tumor was taken prior to treatment (n=62) and post-treatment tumor material (n=40) was obtained during surgery 20.7 (±9.6) days later. Paired material was available for 27/74 patients. Differential analysis comparing gene expression before and after Tamoxifen treatment implicated activation of the NFκB pathway and an enrichment of EMT/stemness features upon Tamoxifen treatment. In line with these findings, exposure of ER+ breast cancer cell lines to tamoxifen, in vitro and in vivo, gives rise to a tamoxifen-tolerant population with similar NFκB activity and EMT/stemness characteristics as described in the corresponding publication.

ORGANISM(S): Homo sapiens

PROVIDER: GSE147271 | GEO | 2020/04/06

REPOSITORIES: GEO

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Gene expression of primary breast cancers from patients before and after neo-adjuvant Tamoxifen treatment

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