The vitamin D receptor is involved in the regulation of human breast cancer cell growth via a ligand-independent function in cytoplasm

Autor: Sutha John, Suzanne Schillo, Colin R. Dunstan, Hong Zhou, Yu Zheng, Theresa A. Guise, Pierrick G.J. Fournier, Khalid S. Mohammad, Sreemala Murthy, Trupti Trivedi, Markus J. Seibel
Rok vydání: 2017
Předmět:
0301 basic medicine
Cytoplasm
Gene Expression
Apoptosis
vitamin D
Ligands
Calcitriol receptor
Mice
0302 clinical medicine
polycyclic compounds
bone metastasis
Gene knockdown
digestive
oral
and skin physiology

Bone metastasis
3. Good health
Protein Transport
Oncology
Gene Knockdown Techniques
030220 oncology & carcinogenesis
Heterografts
lipids (amino acids
peptides
and proteins)

Female
Signal transduction
Osteosclerosis
Research Paper
musculoskeletal diseases
medicine.medical_specialty
ligand independent
Bone Neoplasms
Breast Neoplasms
03 medical and health sciences
breast cancer
Cell Line
Tumor

Internal medicine
medicine
Vitamin D and neurology
Animals
Humans
vitamin D receptor
Cell Proliferation
business.industry
Cell growth
medicine.disease
Disease Models
Animal

030104 developmental biology
Endocrinology
Mutation
Cancer cell
Cancer research
Receptors
Calcitriol

business
Zdroj: Oncotarget
ISSN: 1949-2553
DOI: 10.18632/oncotarget.15803
Popis: // Trupti Trivedi 1, 2 , Yu Zheng 1 , Pierrick G.J. Fournier 2, 5 , Sreemala Murthy 2 , Sutha John 2 , Suzanne Schillo 1 , Colin R. Dunstan 3 , Khalid S. Mohammad 2 , Hong Zhou 1 , Markus J. Seibel 1, 4 , Theresa A. Guise 2 1 Bone Research Program, ANZAC Research Institute, University of Sydney, Sydney, Australia 2 Division of Endocrinology, Department of Medicine, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana, USA 3 Department of Biomedical Engineering, University of Sydney, Sydney, Australia 4 Department of Endocrinology and Metabolism, Concord Hospital, Concord, Sydney, Australia 5 Biomedical Innovation Department, Scientific Research and High Education Center from Ensenada (CICESE), Ensenada, Baja California, Mexico Correspondence to: Theresa A. Guise, email: tguise@iu.edu Markus J. Seibel, email: markus.seibel@sydney.edu.au Keywords: breast cancer, vitamin D, vitamin D receptor, ligand independent, bone metastasis Received: November 04, 2016 Accepted: February 15, 2017 Published: March 01, 2017 ABSTRACT Vitamin D has pleiotropic effects on multiple tissues, including malignant tumors. Vitamin D inhibits breast cancer growth through activation of the vitamin D receptor (VDR) and via classical nuclear signaling pathways. Here, we demonstrate that the VDR can also function in the absence of its ligand to control behaviour of human breast cancer cells both outside and within the bone microenvironment. Stable shRNA expression was used to knock down VDR expression in MCF-7 cells, generating two VDR knockdown clonal lines. In ligand-free culture, knockdown of VDR in MCF-7 cells significantly reduced proliferation and increased apoptosis, suggesting that the VDR plays a ligand-independent role in cancer cell growth. Implantation of these VDR knockdown cells into the mammary fat pad of nude mice resulted in reduced tumor growth in vivo compared with controls. In the intra-tibial xenograft model, VDR knockdown greatly reduced the ability of the cells to form tumors in the bone microenvironment. The in vitro growth of VDR knockdown cells was rescued by the expression of a mutant form of VDR which is unable to translocate to the nucleus and hence accumulates in the cytoplasm. Thus, our data indicate that in the absence of ligand, the VDR promotes breast cancer growth both in vitro and in vivo and that cytoplasmic accumulation of VDR is sufficient to produce this effect in vitro . This new mechanism of VDR action in breast cancer cells contrasts the known anti-proliferative nuclear actions of the VDR-vitamin D ligand complex.
Databáze: OpenAIRE