PMID- 23636418 OWN - NLM STAT- MEDLINE DCOM- 20131218 LR - 20141120 IS - 1432-0878 (Electronic) IS - 0302-766X (Linking) VI - 352 IP - 3 DP - 2013 Jun TI - Breast cancer tissue slices as a model for evaluation of response to rapamycin. PG - 671-84 LID - 10.1007/s00441-013-1608-8 [doi] AB - Rapamycin is a selective inhibitor of the mammalian target of rapamycin (mTOR), a regulator kinase that integrates growth factors signaling via the phosphoinositide-3-kinase pathway and that has emerged as a novel therapeutic modality in breast cancer (BC). We propose a pre-clinical "ex-vivo" personalized organotypic culture of BC that preserves the microenvironment to evaluate rapamycin-mediated gene expression changes. Freshly excised ductal invasive BC slices, 400 mum thick (n=30), were cultured in the presence or absence (control) of rapamycin (20 nM) for 24 h. Some slices were formalin-fixed for immunohistochemical determinations and some were processed for microarray analysis. Control slices in culture retained their tissue morphology and tissue viability (detected by BrdU uptake). The percentage of proliferating cells (assessed by Ki67) did not change up to 24 h of treatment. Immunohistochemical evaluation of p-AKT, p-mTOR, p-4EBP1 and p-S6K1 indicated that AKT/mTOR pathway activation was maintained during cultivation. For microarray analysis, slices were divided into two groups, according to the presence/absence of epidermal growth factor receptor-type 2 and analyzed separately. Limited overlap was seen among differentially expressed genes after treatment (P<0.01) in both groups suggesting different responses to rapamycin between these BC subtypes. Ontology analysis indicated that genes involved in biosynthetic processes were commonly reduced by rapamycin. Our network analysis suggested that concerted expression of these genes might distinguish controls from treated slices. Thus, breast carcinoma slices constitute a suitable physiological tool to evaluate the short-term effects of rapamycin on the gene profile of individual BC samples. FAU - Grosso, Stana Helena Giorgi AU - Grosso SH AD - Instituto Brasileiro de Controle do Cancer, Av. Alcantara Machado 2576, CEP 03102-002, Sao Paulo, SP, Brasil. FAU - Katayama, Maria Lucia Hirata AU - Katayama ML FAU - Roela, Rosimeire Aparecida AU - Roela RA FAU - Nonogaki, Suely AU - Nonogaki S FAU - Soares, Fernando Augusto AU - Soares FA FAU - Brentani, Helena AU - Brentani H FAU - Lima, Leandro AU - Lima L FAU - Folgueira, Maria Aparecida Azevedo Koike AU - Folgueira MA FAU - Waitzberg, Angela Flavia Logullo AU - Waitzberg AF FAU - Pasini, Fatima Solange AU - Pasini FS FAU - Goes, Joao Carlos Guedes Sampaio AU - Goes JC FAU - Brentani, M Mitzi AU - Brentani MM LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20130501 PL - Germany TA - Cell Tissue Res JT - Cell and tissue research JID - 0417625 RN - 0 (Ki-67 Antigen) RN - 0 (Neoplasm Proteins) RN - 0 (Phosphoproteins) RN - EC 2.7.10.1 (ERBB2 protein, human) RN - EC 2.7.10.1 (Receptor, ErbB-2) RN - W36ZG6FT64 (Sirolimus) SB - IM MH - Adult MH - Aged MH - Aged, 80 and over MH - Breast Neoplasms/*drug therapy/genetics/metabolism/pathology MH - Female MH - Gene Expression Profiling MH - Gene Expression Regulation, Neoplastic/drug effects MH - Gene Regulatory Networks/drug effects MH - Humans MH - Immunohistochemistry MH - Ki-67 Antigen/metabolism MH - Middle Aged MH - *Models, Biological MH - Neoplasm Proteins/genetics/metabolism MH - Phosphoproteins/genetics/metabolism MH - Receptor, ErbB-2/metabolism MH - Sirolimus/pharmacology/*therapeutic use MH - Tissue Culture Techniques EDAT- 2013/05/03 06:00 MHDA- 2013/12/19 06:00 CRDT- 2013/05/03 06:00 PHST- 2012/07/12 00:00 [received] PHST- 2013/03/04 00:00 [accepted] PHST- 2013/05/03 06:00 [entrez] PHST- 2013/05/03 06:00 [pubmed] PHST- 2013/12/19 06:00 [medline] AID - 10.1007/s00441-013-1608-8 [doi] PST - ppublish SO - Cell Tissue Res. 2013 Jun;352(3):671-84. doi: 10.1007/s00441-013-1608-8. Epub 2013 May 1.