Table 1.
Preclinical studies on interleukins (ILs) and breast cancer bone metastases.
| References | Interleukin(s) Identified | Interleukin Source | Aims | Experimental Approaches |
|---|---|---|---|---|
| [68] | IL-8 | Breast cancer cells | Evaluate the influence of the expression of IL-8 on bone resorption in osteolytic breast cancer cell lines. | In vitro MDA-MB-231, MDA-231B, T-47D, ZR-75-1 culture. |
| [54] | IL-6 IL-8 |
Osteoblasts | Evaluate osteoblasts inflammatory stress response (IL-6, IL-8) in presence of metastatic breast cancer cells. | In vitro hFOB 1.19 co-culture with MDA-MB-231 CM; hFOB 1.19 and MDA-MB-231 co-culture. |
| [18] | IL-1β | Osteoblasts | Evaluate if OPG production by breast cancer cells, pretreated or not with IL-1β, correlates with bone colonization. | In vitro hFOB 1.19 and 435/BRMS1, 231/BRMS1, 231/K and MDA-MB-435 derived from the pleural effusion of a female patient with an infiltrating ductal carcinoma or their CM (pretreated or not with IL-1β) co-culture. |
| [25] | IL-6 | Breast cancer cells | Evaluate fibroblasts isolated from breast cancer metastasis and the link with tumor growth rates. | In vivo and in vitro MCF-7 and BT474 co-cultured with Ped300 and P162 fibroblast cells CM. MCF-7 cells injected s.c. (± fibroblasts) in the dorsal area of BALB/c nude mice |
| [20] | IL-8 | Osteoblasts | Evaluate osteoblast-derived TGF association with osteolytic bone diseases and ILs regulation. | In vitro MDA-231 and MDA-435 co-cultured with MG-63 CM. |
| [55] | IL-6 | Osteoblasts | Evaluate colonization and degradation of osteoblastic tissue by breast cancer cells. | In vitro MDA-MB-231 CM co-cultured with osteoblast tissue. |
| [52] | IL-6 | Peripheral venous blood | Identify clinical significance of serum IL-6 and its correlation with Cyst C in patients. | In vitro Peripheral venous blood from 25 healthy donors,10 patients with age-related osteoporosis, 16 patients with localized breast cancer, 10 patients with breast cancer bone metastases. |
| [34] | IL-8 IL-6 |
Breast cancer cells | Evaluate the activity of S1P and LPA on breast cancer cells to stimulate osteoclasts. | In vitro MDA-MB-231/BO2 (MDA- BO2) CM untreated or treated with S1P and LPA. Mice bone marrow cells cultured with MDA-BO2 CM treated with S1P and LPA. |
| [31] | IL-8 | Breast cancer cells | Evaluate the role of Syndecan-1 in osteoclastogenesis. | In vitro Human PBMC: mCSF present in all groups; RANKL or IL-8 used as positive controls. Human PBMCs that received mCSF cultured with CM from MDA MET-derived cell lines HPSE-high, HPSE-low, M225, and M343. For same cultures, Syndecan-1 immunodepleted from CM using monoclonal antibody BB4 and protein-G sepharose beads. |
| [60] | IL-6 | Osteoblasts | Determine the localization of osteoblast-derived IL-6. | In vivo MDA-MB-231 expressing GFP variant injected into the left cardiac ventricle of athymic mice. |
| [56] | IL-6 IL-8 |
Osteoblasts | Identify key cytokines expressed by osteoblasts in metastatic breast cancer cells. | In vitro and in vivo MC3T3-E1 co-cultured with MDA-MB-231 variants CM; MDA-MB-231 variants injected into the left cardiac ventricle of athymic mice. |
| [47] | IL-1α IL-17 IL-12 |
Breast cancer cells | Evaluate if limiting ET-1 expression and activity (blocking ETAR and ETBR) reduced breast cancer growth and development of tumor infiltration in bone. | In vitro and vivo 4T1 cells injected in C57Bl/6× Balb/C male mice and treated with vehicle) or with ETAR/ETBR dual selective antagonist. 4T1 cells CM treated with ET-1. |
| [57] | IL-6 | Osteoblasts | Evaluate the dynamic interaction between breast cancer cells and osteoblastic tissue. | In vitro MDA-MB-231 and MC3T3-E1 co-culture; MDA-MB-231 inoculated into bioreactor containing osteoblastic tissue. |
| [81] | IL-17B | Bone marrow mesenchymal cells | Evaluate the role of hBMSC in metastatic breast cancer cells. | In vitro and in vivo Migration assay of hBMSC to human BCC (SUM 1315, SUM 1315-BP2, MDA-MB-231 and MCF7), wild type (wt) or over-expressed for IL-17 br, or treated with IL-17B. In vivo metastasis model of hBMSC and breast cancer cells(SUM 1315, SUM 1315-BP2, MDA-MB-231 and MCF7) wt or over-expressed for IL-17 br, co-injected in mice mammary fat pad. |
| [58] | IL-6 | Osteoblasts | Identify if Notch-dependent signaling proteins secreted by osteoblasts may stimulate tumor growth. | In vitro MC3T3-E1 and JAG1 OE breast cancer cells co-culture. |
| [74] | IL-11 | Breast cancer cells | Determine how Runx2 mediates the ability of metastatic breast cancer cells to modulate the activity of bone cells. | In vitro MC3T3-E1 co-cultured with MDA-MB-231 CM or sclerostin-free CM; Mouse BMSCs co-cultured with MDA-MB-231 CM or sclerostin-free CM. |
| [21] | IL-8 IL-11 |
Breast cancer cells | Delineate TGF-β signaling pathways in the production of IL-8 and IL-11 in breast cancer cells with different bone metastatic potential. | In vitro MDA-MB-231, MDA-MB-468, and MCF-7 cultured with TGF-β. MDA-MB-231 treated with SMAD4 RNAis or MAPK14 RNAis and low GC content negative control RNAi and treated with TGFβ-1. |
| [30] | IL-1β IL-8 |
Breast cancer cells | Identify if TAK1 (TGF-β-activated protein kinase 1) effectors contribute to bone metastatic potential of breast cancer cells. | In vitro Suppression of TAK1 signaling in MDA-MB-231 cells by expressing the dominant-negative TAK1-K63W mutant allele or by siRNA. Control: empty-vector. CM from control and dn-TAK1-expressing MDA-MB-231 cells treated with TGF-β1 or/and IL1-β |
| [61] | IL-6 | Evaluate the clinical relevance of gene expression signatures induced by heterotypic interaction of breast cancer cells and osteoblasts. | In vitro Co-culture of HMECs; MCF-7, T47D, MDA-MB-231, SKBR-3 and Hs578T co-culture with primary human osteoblasts. |
|
| [22] | IL-11 | Breast cancer cells | Identify and characterize miRNAs that regulate the TGF-β induction of IL-11 in metastatic breast cancer cells. | In vitro MDA-MB-231(SA) transfected with precursors or miRNA inhibitors and cultured with TGF-β. |
| [23] | IL-11 | Breast cancer cells | Evaluate gene for TGF-β-induced IL-11 production in highly bone metastatic MDA-MB-231(SA) by a cell-based siRNA screen. | In vitro MDA-MB-231(SA) transfected with siRNAs cultured with heparin, fragmin, or K5-NSOS and TGF-β. |
| [24] | IL-6 IL-8 |
Breast cancer cells | Evaluate an unbiased genome-wide miRNA screen to identify miRNAs modulating NF-κB signaling in metastatic breast cancer cells. | In vitro MDA-MB-231 transfected with miR-373 or miR-520c and treated with TNF-α or TGF-β. |
| [83] | IL-20 | Tumor tissue Breast cancer cells |
Evaluate the function of IL-20 in tumor growth, metastasis, and clinical outcome. | In vitro and in vivo IL-20, IL-20 receptors, and anti–IL-20 mAb 7E immunohistochemical staining of tumor tissue samples with primary intraductal carcinoma of the breast, with breast cancer, with tumorous and non-tumorous breast tissue with breast cancer bone metastases, and breast cancer cell lines (MDA-MB231 and MCF-7); Intracardiac and intratibial injection of 4T1-Luc in BALB/c mice. |
| [49] | IL-6 | Serum | Determine serum level of IL-6 protein clinical utility in patients with breast cancer bone metastasis. | In vitro Blood samples from 164 patients with stage I–III breast cancer. |
| [75] | IL-11 | Breast cancer cells | Evaluate the effect of TGFβ-1 on IL-11 production. | In vitro 4T1 cells exposed to different doses TGFβ-1. |
| [35] | IL-6 (Oncostatin M-OSM) |
Breast cancer cells | Evaluate the role of OSM in the formation of bone metastases. | In vitro and in vivo 4T1.2-OSM (OSM expression knocked down using shRNA) and 4T1.2-LacZ (control) injected into the mammary fat pad or intra-tibial in Balb/c mice. RAW 264.7 co-cultured with 4T1.2. |
| [40] | IL-17F IL-1β IL-6 |
Breast cancer cells T-cells |
Evaluate how the pre-metastatic niches arise in the bone tissue. | In vitro and in vivo Inoculation of non- metastatic 67 NR or metastatic 4T1 BCC in the mammary fat pad of BALB/c mice. T-cells from 4T1 tumor-bearing mice KD for RANKL and IL-17F, and transferred into Balb/c nude mice. |
| [77] | IL-11 | Serum Tumor tissue |
Evaluate the relationship between IL-11 and breast cancer bone metastasis in patients. | In vitro Blood samples from patients with bone metastasis, with primary cancer and healthy patients; formalin-fixed, paraffin-embedded tumor tissue (from patients with bone metastasis and from patients with primary cancer); fresh tumor tissue from patients (with primary cancer and with breast cancer metastasis). |
| [78] | IL-11 | Breast cancer cells | Investigate the role of IL-11 in metastasis-induced osteolysis. | In vitro Bone marrow cells from femur and tibia of C56BL/6 mice co-cultured with MDA-MB-231 CM; IL-11 neutralizing antibody added to bone marrow in 20% MDA-MB-231 CM. Bone marrow cultured with IL-11 to generate osteoclasts from IL-11-dependant precursors. |
| [53] | IL-6 IL-8 |
Cancer stem cells | Investigate the ability of non-metastatic human breast cancer stem cells to metastasize to bone. | In vivo Primary CD44+ CD24− breast CSCs-like transduced by luciferase-lentiviral vector injected s.c. and intra-cardiac in immunodeficient mice carrying s.c. human bone implants. Mammospheres derived from patient tumor specimens. |
| [59] | IL-6 | Osteoblasts | Determine whether 3D mineralizing tissue would be a bone surrogate for studying the early stages of breast cancer colonization to bone. | In vitro MC3T3-E1 (grown for 60 days in bioreactor to form a 3D collagenous osteoblastic tissue), pre-osteoclasts (obtained from bone marrow cells harvested from 6- to 9-week-old GFP mice) and MDA-MB-231-GFP. |
| [64] | IL-6 | Breast cancer cells | Investigate the effects of RANKL on cancer cells and the role of tumor-derived IL-6 within the bone microenvironment. | In vitro and in vivo. Normal or modified (silenced IL-6 and RANK via a lentiviral-based system) MDA-MB-231 injected intra-tibial or s.c. in e BALB/c nu/nu mice. |
| [39] | IL-1β | Breast cancer cells | Identify changes in gene and protein expression associated with bone-homing or colonization, developing a novel bone-seeking clone of MDA-MB-231 cells. | In vitro and in vivo Intra-cardiac injection of MDA-P cells in female Balb/c nude mice. Cells that formed colonies in mouse tibiae were extracted and pooled before culture in vitro. Following 1 week of culture, cells were re-injected into the mice left cardiac ventricle or tail vein. Procedure repeated 7 times until tumor growth in mouse long bones was detected following intravenous injection (MDA-IV). |
| [62] | IL-6 | Breast cancer cells | Assess the effect of soluble mediators produced by breast cancer cells on human osteoclast maturation. | In vitro Differentiation toward osteoclasts (from healthy volunteer) induced by α-MEM supplemented with MCS-F and RANKL or by α-MEM supplemented with 10% MDA-MB-231 (CM). |
| [69] | IL-8 | Plasma | Identify IL-8 association with increased bone resorption and breast cancer bone metastasis. | In vitro and in vivo Plasma from patients with or without bone metastasis from breast cancer; MDA-MET injected into the tibia of nude mice and 7 days later treated daily with a neutralizing IL-8 monoclonal antibody. |
| [48] | IL-2 IL-6 |
Blood | Evaluate the possible relationship between RPT efficacy and cytokines levels. | In vitro Blood samples from patients with bone metastases. |
| [72] | IL-8 | Osteoblasts | Test the cell migration stimulated by OCM. | In vitro MCF-7 cultured with hFOB1.19 human osteoblasts CM. |
| [44] | IL-1β | Osteoblasts | Test if bone remodeling cytokines could stimulate dormant cells to grow. | In vitro MDA-MB-231BRMS1 and MC3T3-E1 co-cultured in a long term 3D system. |
| [71] | IL-8 | Osteoblasts | Evaluate the link between osteoblasts and breast cancer cells in healthy and osteoporotic conditions. | In vitro Osteoblasts isolated from trabecular bone of iliac crest of SHAM and OVX rats co-cultured with MRMT-1 rat breast cancer cells CM. |
| [41] | IL-1β | Breast cancer cells | Identify parameters of human bone tissue associated with breast cancer cell osteotropism and colonization. | In vitro MDA-MB-231-fLuc-EGFP and MCF-7-fLuc-EGFP co-cultured with cancellous bone tissue fragments from patients. |
| [26] | IL-6 | Breast cancer cells | Evaluate the association between HT and breast cancer bone metastases. | In vitro and in vivo Tumor-derived cancer cells from xenografts and primary human ductal carcinoma tissues. Xenografts from tumorigenic MCF7 clones administered with tamoxifen citrate implants, fulvestrant and tocilizumab. Cancer cells injected bilaterally in the mammary fat pads of NOD/SCID mice. |
| [27] | IL-6 | Breast cancer cells | Evaluate the ability of CaSR to play a chemotactic and pro-angiogenic role in MDA-MB-231 breast cancer cells by cytokines secretion. | In vitro MDA-MB-231 and MCF-12A CM stimulated with different Ca2+ concentrations. |
| [42] | IL-1β | Breast cancer cells | Generate a clinically relevant model for the study of breast cancer tumor cell-bone interactions. | In vitro and in vivo Human bone discs from patients and DiD labeled MDA-MB-231-luc2 co-culture; tumor-cell bearing bone discs implanted s.c. into the flanks of NOD SCID nude mice; MDA-MB-231 luc2 injected into the hind mammary fat pads of NOD SCID nude mice. |
| [70] | IL-8 | Breast cancer cells | Investigate breast cancer cell IL-8 expression in response to systematic changes of HA. | In vitro MDA-MB-231, MCF-7, MCF10A, MCF10AT1, and MCFDCIS breast cell seeded onto mineral coatings Poly (d,l-lactide-co-glycolide) PLG. |
| [66] | IL-6 | Osteoblasts | Study reactive senescent osteoblasts and evaluate if they increased breast cancer colonization to bone. | In vitro and in vivo NT2.5 and BMMs co-cultured with senescent or non-senescent FASST osteoblasts CM + IL-6 neutralization antibody or IgG control; senescent vs. control osteoblasts co-cultured with mice BMMs. NT2.5luc injected into the left cardiac ventricle of FASST or littermate control mice that received either anti-murine IL-6 antibody or anti-murine IgG2a antibody. |
| [67] | IL-6 IL-8 |
Breast cancer cells | Evaluate the effect of LMW-PTP slow isoform in tumor cell induced osteoclastogenesis | In vitro MDA-MB-435 KD for LMW-PTP co-cultured with Raw 264.7. |
| [82] | IL-18 | Serum | Compare serum IL-18 levels in breast cancer patients with and without bone metastases | In vitro Blood samples from female breast cancer patients with or without bone metastases and from healthy subjects. |
| [79] | IL-11RA | Tumor tissue | Analyze expression of IL11-RA in advanced breast cancer patients with or without bone metastasis. | In vitro Human tissue samples from breast cancer patients with or without bone metastases. |
| [80] | IL-15 | Tumor tissue Breast cancer cells |
Study JAK/STAT pathway in the bone metastasis from breast cancer. | In vitro and in vivo Breast cancer and bone metastases biopsies from patients. Intra-mammary and intra-cardiac injection of MDA-MB-231 scp1833 and EO771 cells in nude mice. |
| [45] | IL-1 | Breast cancer cells | Investigate the blocking IL-1R signaling with the clinically licensed antagonist, i.e., anakinra. | In vitro and in vivo Co-culture of MDA-MB-231-IV (eGFP-expressing bone-homing derivative of MDA-MB-231) or MCF7 with HS5 human bone marrow cells. Mice pretreated with anakinra or placebo starting 3 days before injection of MCF7 or MDAMB- 231-IV cells s.c. or i.v. via the lateral tail vein; MDA-MB-231-IV cells injected s.c. or i.v. 7 days prior to commencement of anakinra treatment. Mice injected with MCF7 cells were supplemented with B-estradiol. |
| [50] | IL-6 | Serum | Evaluate serum levels of IL-6 in breast cancer patients with or without metastasis. | In vitro Blood samples from patients with breast cancer, with metastatic breast cancer and from healthy subjects. |
| [43] | IL-6 IL-1β IL-10 IL-8 |
Breast cancer cells | Evaluate the relationship between osteoporosis and breast cancer-derived bone metastases in a humanized 3D model. | In vitro Bone tissue samples from healthy and osteoporotic patients co-cultured with MCF-7. |
| [36] | IL-6 | Breast cancer cells | Identify tumor-secreted cytokines regulated by the ABL kinases that promote breast cancer metastasis to bone. | In vitro CM of 1833 (bone metastasis sub-line derived from MDA-MB-231 breast cancer cells) cells transduced with control shRNA (Scr) or shRNAs against ABL1 and ABL2 (shAA). The Cancer Genome Atlas dataset analyses. |
| [37] | IL-8 | Osteoblasts | Evaluate Sema4D-mediated induction of IL-8 and LIX/CXCL5. | In vitro and in vivo HOB and MC3T3 CM cultured with Sema4D. HOB cultured with CM by MDA-MB-231 or cells silenced for Sema4D, with and without Clostridium botulinum toxin C3. RAW264.7 cultured with RANKL, IL-8, or CM by HOB treated with sSema4D or empty vector transfected controls and anti-IL-8 antibody. MDA-MB-231 infected ex vivo with control virus or lentivirus coding for Sema4D shRNA injected into the left cardiac ventricle of nude mice. |
| [73] | IL-8 | Breast cancer cells | Investigate the interaction between breast cancer cell and osteoblasts in a 3D printed bone matrices. | In vitro hFOB and MDA-MB-231 cells co-cultured on bone matrix. |
| [51] | IL-6 | Blood | Assess the correlation between sYB-1 and serum IL-6 in patients with breast cancer bone metastasis. | In vitro Peripheral blood from patients with breast cancer bone metastasis. |
| [19] | IL-1β | Breast cancer cells Macrophages |
Evaluate the link between OPG, macrophages, and IL-1β. | In vitro MDA-MB-231, MDAMB-436, BT549, SKBR3, ZR75-1, HCC1954 human breast cancer cells transfected with OPG Stealth RNA siRNA; Breast cancer cells and THP-1 monocyte cells (previously treated with PMA to induce macrophage differentiation) co-culture. |
| [65] | IL-6 | Breast cancer cells | Study the effects of IL-6 receptor on breast cancer aggressiveness and bone metastases. | In vitro and in vivo MDA-MB-231 cultured in presence or absence of tocilizumab (anti-human IL-6 receptor (IL-6R). Intracardiac injection of MDA-MB-231 in BALB/c nu/nu mice. |
| [28] | IL-6 | Breast cancer cells | Evaluate the inhibition of IL-6 signaling using a molecule antagonist, TB-2-081, on bone integrity, tumor progression, and pain. | In vitro and in vivo MAT B III cells pretreated with either vehicle or TB-2-081. Intratibial injection of MAT B III in Fisher F344/NhSD rats and treatment with either vehicle or TB-2-08. Osteoblasts harvested from 24- to 48-hour-old neonatal Fischer F344/NhSD pups exposed to vehicle or TB-2-081 pretreatment before challenge of IL-6 recombinant protein. |
| [76] | IL-11 | Breast cancer cells | Investigate miR-124/IL-11 in the prognosis of breast cancer patients with bone metastasis. | In vitro and in vivo MDA-MB-231 cells transfected with miR-124 mimic (miR-124) and MCF7 cells transfected with miR-124 inhibitor (in-miR-124). MCF7 stably expressing miR-124 inhibitor or NC inoculated into left ventricle of nude mice. |
| [38] | IL-6 (Oncostatin M-OSM) |
Macrophage | Evaluate OSM induced macrophage M2 polarization during breast cancer bone metastasis. |
In vitro and in vivo MDA-MB-231 CM cultured under hypoxia or normoxia with THP-1 cells differentiated to macrophages. BALB/c mice s.c. injected with 2 doses of 4T1 cells in the T4 of mammary fat pad. Mouse PBMCs transfected with the siRNA targeted against Rictor and quantum dots (Q-Dots) before being reintroduced in mice. Macrophages isolated from tumor tissue. |
| [33] | IL-8 IL-11 |
Breast cancer cells | Evaluate the role of LPA in the regulation of osteoclastogenic cytokines from breast cancer cells. | In vitro MDA-MB-231 CM and MDA-MB-468 containing LPA co-cultured with RAW264.7 cells |
| [32] | IL-11 | Breast cancer cells | Evaluate the role of IL-11 in bone metastasis from breast cancer. | In vitro and in vivo MCF-7, MDA-MB-231 and BoM-1833 CMs (infected with UBI-MCS-EGFP-SV40-Firefly-Luciferase-IRES Puromycin) co-cultured with BMMs (transfected with siRNA against mouse STAT3, c-Myc, and control si-RNA). Block of osteolytic factors in BoM-1833 cells CM through monoclonal antibodies against VEGF, PTHrP, IL-11, and CTGF. MCF-7, MDA-MB-231, and BoM-1833 injected into femur of BALB/c-nu/nu nude mice. STAT3 inhibitor AG-490 i.v. injected every 2 days for 3 weeks. |
| [63] | IL-6 | Breast cancer cells | Evaluate TNF-α and IL-6 in the pathophysiology of pain syndrome in breast cancer bone metastasis. | In vivo Tumor section, obtained from Sprague-Dawley rats injected s.c. with CRL-1666 breast cancer cells, implanted in L6 vertebra bone defect. |
| [46] | IL-1β | Breast cancer cells | Identify how tumor cell derived IL-1β drives breast cancer progression and bone metastasis; effect of targeting the IL-1β pathway using the anti-human IL-1β antibody, canakinumab, and IL-1R antagonist, anakinra. | In vitro and in vivo Patient tissues with stage II/III breast cancer. MDA-MB-231, MCF-7, and T47D cells (transfected to over-express IL-1β or IL-1R1) co-cultured with OB1. MDA-MB-231 or T47D cells co-cultured with human bone discs. Human bone discs implanted s.c. into NOD SCID mice; after 4 weeks MDA-MB-231 Luc2-TdTomato, MCF7 Luc2, or T47D Luc2 injected into hind mammary fat pads. IL-1Ra or canakinumab s.c. in NOD SCID mice, starting 7 days after injection of tumor cells. IL-1Ra administered for 21 or 31 days or canakinumab administered as a single s.c. injection in BALB/c and C57BL/6 mice. Injection of MDA-MB-231 GFP, MDA-MB-231 IV, MDA-MB-231 IL-1B+, or MDA-MB-231 IL-1R1+ cells into tail vein of BALB/c nude mice or following intra-ductal injection of E0771 into mammary ducts of IL-1B-KO or fl/fl. |
| [29] | IL-8 | Breast cancer cells | Evaluate the knockdown of Osx in breast cancer bone metastasis. | In vivo Transfected MDA-MB 231 cells with stable Osx knockdown or Osx over-expression, injected into the tibiae of nude mice. |
Abbreviation: IL = interleukin; CM = conditioned medium; OPG = osteoprotegerin; hFOB = human fetal osteoblast; β = beta; 2D = two dimensional; 3D = three dimensional; STAT3 = signal transducer and activator of transcription 3; CA-IX = carbonic anhydrase isoenzyme IX; TGF = transforming growth factor; MAPK = mitogen-activated protein kinase; BMP-2 = bone morphogenetic protein 2; IGF-1 = insulin-like growth factor 1; AP-1 = activator protein 1; NF-κB = nuclear factor kappa-light-chain-enhancer of activated B cells; Cyst C = cystatin C; GFP = green fluorescent protein; TRAP = tartrate-resistant acid phosphatase; RANKL = receptor activator of nuclear factor kappa-Β ligand; ET-1 = endothelin-1; ETR = endothelin receptor; dH2O = distilled water; α = alpha; Runx2 = runt-related transcription factor 2; CBFβ = core-binding factor β; RNAis = RNA interference; GC = guanine–cytosine; HMECs = human mammary epithelial cells; K5-NSOS = k5-derived heparin-like polysaccharide; HS6ST = heparan sulfate 6 osulfotransferase; HS3ST1 = heparan sulfate glucosamine 3-O-sulfotransferase 1; HLGAG = heparin-like glycosaminoglycan; TNF = tumor necrosis factor; mAb = monoclonal antibody; LN = lymph nodes; CSCs = cancer stem cells; α-MEM = minimum essential medium α; M-CSF = macrophage colony-stimulating factor; ER = estrogen; RPT = radionuclide palliative therapy; OCM = osteoblast-conditioned medium; RB = receptor type B; PGE2 = prostaglandin E2; SHAM = sham-operated; OVX = ovariectomized; HT = hormonal therapy; MS = mammosphere; OXPHOS = oxidative phosphorylation; CaSR = calcium sensing receptor; HA = hydroxyapatite; PLG = poly (d,l-lactide-co-glycolide); mSBF = modified simulated body fluid; IgG = immunoglobulin G; BMMs = bone marrow macrophages; ROC = receiver operating characteristic; s.c. = subcutaneously; i.v. = intravenously; sYB-1 = synaptobrevin homolog 1; MMP-3 = matrix metalloproteinase-3; PMA = phorbol 12-myristate 13-acetate; IL-6R = anti-human IL-6 receptor; VEGF = vascular endothelial growth factor; NC = negative control; LPA = lysophosphatidic acid; LPARs = lysophosphatidic acid receptors; EMT = epithelial-to-mesenchymal transition; Osx = Osterix; S1P = sphingosine 1-phosphate; HPSE-low = heparanase; TAK1 = TGF-β-activated protein kinase 1; OSM = oncostatin M; OSMRβ = oncostatin M receptor β; LIFRβ = Leukemia Inhibitor Factor receptor β; LMW-PTP = low-molecular-weight protein tyrosine phosphatase; PTHrP= Parathyroid hormone-related protein; CTGF = connective tissue growth factor.