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Series GSE32646 Query DataSets for GSE32646
Status Public on Mar 20, 2012
Title GSTP1 expression predicts poor pathological complete response to neoadjuvant chemotherapy in ER-negative breast cancer
Organism Homo sapiens
Experiment type Expression profiling by array
Summary The purpose of the present study was to investigate the association of glutathione S-transferase P1 (GSTP1) expression with resistance to neoadjuvant paclitaxel followed by 5-fluorouracil/epirubicin/cyclophosphamide (P-FEC) in human breast cancers. The relationship of GSTP1 expression and GSTP1 promoter hypermethylation with intrinsic subtypes was also investigated. In this study, primary breast cancer patients (n = 123, stage II-III) treated with neoadjuvant P-FEC were analyzed. Tumor samples were obtained by vacuum-assisted core biopsy before P-FEC. GSTP1 expression was determined using immunohistochemistry, GSTP1 promoter methylation index (MI) using bisulfite methylation assay and intrinsic subtypes using DNA microarray. The pathological complete response (pCR) rate was significantly higher in GSTP1-negative tumors (80.0%) than GSTP1-positive tumors (30.6%) (P = 0.009) among estrogen receptor (ER)-negative tumors but not among ER-positive tumors (P = 0.267). Multivariate analysis showed that GSTP1 was the only predictive factor for pCR (P = 0.013) among ER-negative tumors. Luminal A, luminal B and HER2-enriched tumors showed a significantly lower GSTP1 positivity than basal-like tumors (P = 0.002, P < 0.001 and P = 0.009, respectively), while luminal A, luminal B and HER2-enriched tumors showed a higher GSTP1 MI than basal-like tumors (P = 0.076, P < 0.001 and P < 0.001, respectively). In conclusion, these results suggest the possibility that GSTP1 expression can predict pathological response to P-FEC in ER-negative tumors but not in ER-positive tumors. Additionally, GSTP1 promoter hypermethylation might be implicated more importantly in the pathogenesis of luminal A, luminal B and HER2-enriched tumors than basal-like tumors.
Overall design Fresh frozen tumor samples obtained by vacuum-assisted core biopsy from one hundred and fifteen patients were subjected to RNA extraction and hybridization on Affymetrix microarrays.
Contributor(s) Miyake T, Nakayama T, Naoi Y, Yamamoto N, Otani Y, Kim S, Shimazu K, Shimomura A, Maruyama N, Tamaki Y, Noguchi S
Citation(s) 22320227
Submission date Oct 05, 2011
Last update date Jun 06, 2022
Contact name Shinzaburo Noguchi
Phone +81-6-6879-3772
Fax +81-6-6879-3779
Organization name Osaka University, Graduate School of Medicine
Department Breast and Endocrine Surgery
Street address 2-2-E10 Yamada-oka
City Suita
State/province Osaka
ZIP/Postal code 565-0871
Country Japan
Platforms (1)
GPL570 [HG-U133_Plus_2] Affymetrix Human Genome U133 Plus 2.0 Array
Samples (115)
GSM809184 Breast cancer tumor OU-1
GSM809185 Breast cancer tumor OU-2
GSM809186 Breast cancer tumor OU-3
BioProject PRJNA146953

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE32646_RAW.tar 532.5 Mb (http)(custom) TAR (of CEL)
Processed data included within Sample table

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