title: Heparins modulate the IFN-γ-induced production of chemokines in human breast cancer cells.
abstract: Heparins seem to improve survival in patients with advanced malignancies independently of their anticoagulatory function. As the treatment options in advanced and metastatic breast cancer are still very limited, heparins might be an interesting addition to the existing systemic therapies. The interferon (IFN)-γ-inducible chemokines CXCL9 and CXCL10 play an essential role in the regulation of the immune milieu in malignant tumours, thereby being interesting targets for an immunological intervention. We therefore wanted to test whether heparins have an impact on the chemokines CXCL9 and CXCL10 as well as the IFN-γ signalling in human breast cancer cells in vitro. The well-established cell lines BT-474, MCF-7, SK-BR-3 and MDA-MB-231 were incubated with IFN-γ, unfractionated heparin (UFH), different low molecular weight heparins (LMWHs) and the heparin-related polyanions danaparoid and dextran sulphate. The production of CXCL9 and CXCL10 was measured by ELISA and real-time RT-PCR, the phosphorylation of signal transducer and activator of transcription (STAT) 1 was detected by an in-cell western assay and the amount of cellular bound IFN-γ was analysed by a high sensitivity ELISA. We observed that IFN-γ induced CXCL9 and CXCL10 production in MCF-7, SK-BR-3 and MDA-MB-231 cells but not in BT-474. UFH dose dependently inhibited the effect of IFN-γ on the secretion and expression of CXCL9 and CXCL10. LMWHs and heparin-related compounds differentially modulated IFN-γ-effects-the results depended on their molecular size and charge, but were independent of their anticoagulatory properties. As a reason for these heparin effects, we could show that the IFN-γ-induced phosphorylation of STAT1 was modulated by heparins, caused by an interaction with the cellular binding of IFN-γ. In conclusion, these results support the significance of the immunomodulatory properties of heparins independently of their classical anticoagulatory function. Heparin-derived sulphated polysaccharides with distinct molecular properties might thus be interesting candidates for new therapeutic strategies in breast cancer.
authors.affiliation: Department of Obstetrics and Gynecology, University of Greifswald, Sauerbruchstr., 17475 Greifswald, Germany. herbert.fluhr@uni-greifswald.de
authors.forename: Herbert
authors.initials: H
authors.lastname: Fluhr
authors.forename: Tina
authors.initials: T
authors.lastname: Seitz
authors.forename: Marek
authors.initials: M
authors.lastname: Zygmunt
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D054357:Chemokine CXCL10 / Q000235:genetics / Q000378:metabolism*; D054370:Chemokine CXCL9 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000502:physiology*; D010766:Phosphorylation; D011485:Protein Binding; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D050794:STAT1 Transcription Factor / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects*
chemical_list: D000970:Antineoplastic Agents; C114753:CXCL10 protein, human; C080810:CXCL9 protein, human; D054357:Chemokine CXCL10; D054370:Chemokine CXCL9; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D007371:Interferon-gamma; D006493:Heparin