title: Exogenous regucalcin suppresses the proliferation of human breast cancer MDA-MB-231 bone metastatic cells in vitro.
abstract: Regucalcin serves a pivotal role as a suppressor protein in signal transduction in various types of cells and tissues. The regucalcin gene, which is localized on the X chromosome, consists of seven exons and six introns. Reductions in the gene expression of regucalcin have been suggested to serve a role in hepatocarcinogenesis in animal models and human patients, indicating a potential role as a suppressor protein in cancer. The aim of the current study was to investigate the effect of exogenous regucalcin on cell proliferation in the cloned human breast cancer MDA‑MB‑231 bone metastatic cell line in vitro. The proliferation of MDA‑MB‑231 cells was suppressed following the addition of regucalcin (0.1‑10 nM) in vitro. The suppression of proliferation was not enhanced in the presence of tumor necrosis factor‑α, PD98059, staurosporine, Bay K8644, wortmannin, 5,6‑dichloro‑1‑β‑D‑ribofuranosylbenzimidazole or gemcitabine. Exogenous regucalcin did not induce cell death in MDA‑MB‑231 cells in vitro. These data suggest that exogenous regucalcin possesses suppressive effects on the proliferation of human breast cancer MDA‑MB‑231 bone metastatic cells, and that this effect may be mediated through various intracellular signaling pathways in vitro. Exogenous regucalcin is suggested to function as a suppressor in cancer cell proliferation.
authors.affiliation: Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Yamaguchi
authors.affiliation: Laboratory of Analytical Neurobiology, Faculty of Pharmacy, Meijo University, Nagoya, Aichi 468-8503, Japan.
authors.forename: Tomiyasu
authors.initials: T
authors.lastname: Murata
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000556:secondary*; D001842:Bone and Bones / Q000187:drug effects / Q000473:pathology*; D001940:Breast / Q000187:drug effects / Q000473:pathology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002135:Calcium-Binding Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D002265:Carboxylic Ester Hydrolases; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats
chemical_list: D000970:Antineoplastic Agents; D002135:Calcium-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D002265:Carboxylic Ester Hydrolases; C513325:Rgn protein, rat