Transcriptional effects of 1,25 dihydroxyvitamin $ D_{3} $physiological and supra-physiological concentrations in breast cancer organotypic culture

Background Vitamin D transcriptional effects were linked to tumor growth control, however, the hormone targets were determined in cell cultures exposed to supra physiological concentrations of 1,25(OH)2$ D_{3} $ (50-100nM). Our aim was to evaluate the transcriptional effects of 1,25(OH)2$ D_{3} $ in...
Ausführliche Beschreibung

Background Vitamin D transcriptional effects were linked to tumor growth control, however, the hormone targets were determined in cell cultures exposed to supra physiological concentrations of 1,25(OH)2$ D_{3} $ (50-100nM). Our aim was to evaluate the transcriptional effects of 1,25(OH)2$ D_{3} $ in a more physiological model of breast cancer, consisting of fresh tumor slices exposed to 1,25(OH)2$ D_{3} $ at concentrations that can be attained in vivo. Methods Tumor samples from post-menopausal breast cancer patients were sliced and cultured for 24 hours with or without 1,25(OH)2$ D_{3} $ 0.5nM or 100nM. Gene expression was analyzed by microarray (SAM paired analysis, FDR≤0.1) or RT-qPCR (p≤0.05, Friedman/Wilcoxon test). Expression of candidate genes was then evaluated in mammary epithelial/breast cancer lineages and cancer associated fibroblasts (CAFs), exposed or not to 1,25(OH)2$ D_{3} $ 0.5nM, using RT-qPCR, western blot or immunocytochemistry. Results 1,25(OH)2$ D_{3} $ 0.5nM or 100nM effects were evaluated in five tumor samples by microarray and seven and 136 genes, respectively, were up-regulated. There was an enrichment of genes containing transcription factor binding sites for the vitamin D receptor (VDR) in samples exposed to 1,25(OH)2$ D_{3} $ near physiological concentration. Genes up-modulated by both 1,25(OH)2$ D_{3} $ concentrations were CYP24A1, DPP4, CA2, EFTUD1, TKTL1, KCNK3. Expression of candidate genes was subsequently evaluated in another 16 samples by RT-qPCR and up-regulation of CYP24A1, DPP4 and CA2 by 1,25(OH)2$ D_{3} $ was confirmed. To evaluate whether the transcripitonal targets of 1,25(OH)2$ D_{3} $ 0.5nM were restricted to the epithelial or stromal compartments, gene expression was examined in HB4A, C5.4, SKBR3, MDA-MB231, MCF-7 lineages and CAFs, using RT-qPCR. In epithelial cells, there was a clear induction of CYP24A1, CA2, CD14 and IL1RL1. In fibroblasts, in addition to CYP24A1 induction, there was a trend towards up-regulation of CA2, IL1RL1, and DPP4. A higher protein expression of CD14 in epithelial cells and CA2 and DPP4 in CAFs exposed to 1,25(OH)2$ D_{3} $ 0.5nM was detected. Conclusions In breast cancer specimens a short period of 1,25(OH)2$ D_{3} $ exposure at near physiological concentration modestly activates the hormone transcriptional pathway. Induction of CYP24A1, CA2, DPP4, IL1RL1 expression appears to reflect 1,25(OH)2$ D_{3} $ effects in epithelial as well as stromal cells, however, induction of CD14 expression is likely restricted to the epithelial compartment. Ausführliche Beschreibung

Autor*in:	Milani, Cintia [verfasserIn] Katayama, Maria Lucia Hirata de Lyra, Eduardo Carneiro Welsh, JoEllen Campos, Laura Tojeiro Brentani, M Mitzi Maciel, Maria do Socorro Roela, Rosimeire Aparecida del Valle, Paulo Roberto Góes, João Carlos Guedes Sampaio Nonogaki, Suely Tamura, Rodrigo Esaki Folgueira, Maria Aparecida Azevedo Koike

Format:	E-Artikel
Sprache:	Englisch

Erschienen:	2013

Schlagwörter:	Breast cancer Calcitriol Gene expression Organotypic culture

Anmerkung:	© Milani et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (

Übergeordnetes Werk:	Enthalten in: BMC cancer - London : BioMed Central, 2001, 13(2013), 1 vom: 15. März
Übergeordnetes Werk:	volume:13 ; year:2013 ; number:1 ; day:15 ; month:03

Links:	Volltext

DOI / URN:	10.1186/1471-2407-13-119

Katalog-ID:	SPR027645134