Inhibition of hyaluronan synthesis alters sulfated glycosaminoglycans deposition during chondrogenic differentiation in ATDC5 cells.

In chondrogenic differentiation, expression and collaboration of specific molecules, such as aggrecan and type II collagen, in extracellular matrix (ECM) are crucial. However, few studies have clarified the roles of hyaluronan (HA) in proteoglycan aggregation during chondrogenic differentiation. We assessed the roles of HA in sulfated glycosaminoglycans deposition during chondrogenic differentiation by means of 4-methylumbelliferone (4-MU), an HA synthase inhibitor, using ATDC5 cells. ATDC5 cells were treated with 0.5 mM 4-MU for 7 or 21 days after induction of chondrogenic differentiation with insulin. Depositions of sulfated glycosaminoglycans were evaluated with Alcian blue staining. mRNA expression of ECM molecules was determined using real-time RT-PCR. The deposition of aggrecan and versican was investigated with immunohistochemical staining using specific antibodies. Effects of 4-MU on HA concentrations were analyzed by HA binding assay. 4-MU suppressed the positivity of Alcian blue staining, although this delay was reversible. Interestingly, stronger positivity of Alcian blue staining was observed at day 21 in cultures with 4-MU discontinuation than in the control. 4-MU significantly increased the mRNA expression of aggrecan, versican, and type II collagen, which was consistent with increased deposition of aggrecan and versican. The HA concentration in ECM and cell-associated region was significantly suppressed with 4-MU treatment. We conclude that the inhibition of HA synthesis slows sulfated glycosaminoglycans deposition during chondrogenic differentiation despite the increased deposition of other ECM molecules. Transient starvation of HA with 4-MU accelerates chondrogenic ECM formation, suggesting its potential to stimulate chondrogenic differentiation with adequate use.

EMMPRIN co-expressed with matrix metalloproteinases predicts poor prognosis in patients with osteosarcoma.

Several studies have focused on the relationships between the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and the prognosis of patients with malignant tumors. However, few of these have investigated the expression of EMMPRIN in osteosarcoma. We examined expression levels of EMMPRIN immunohistochemically in 53 cases of high-grade osteosarcoma of the extremities and analyzed the correlation of its expression with patient prognosis. The correlation between matrix metalloproteinases (MMPs) and EMMPRIN expression and the prognostic value of co-expression were also analyzed. Staining positivity for EMMPRIN was negative in 7 cases, low in 17, moderate in 19, and strong in 10. The overall and disease-free survivals (OS and DFS) in patients with higher EMMPRIN expression (strong-moderate) were significantly lower than those in the lower (weak-negative) group (0.037 and 0.024, respectively). In multivariate analysis, age (P=0.004), location (P=0.046), and EMMPRIN expression (P=0.038) were significant prognostic factors for overall survival. EMMPRIN expression (P=0.024) was also a significant prognostic factor for disease-free survival. Co-expression analyses of EMMPRIN and MMPs revealed that strong co-expression of EMMPRIN and membrane-type 1 (MT1)-MMP had a poor prognostic value (P=0.056 for DFS, P=0.006 for OS). EMMPRIN expression and co-expression with MMPs well predict the prognosis of patients with extremity osteosarcoma, making EMMPRIN a possible therapeutic target in these patients.

Nuclear expression of ß-catenin predicts the efficacy of meloxicam treatment for patients with sporadic desmoid tumors.

This study aimed to determine the prevalence of ß-catenin nuclear positivity as a prognostic factor in patients with desmoid tumors (DTs) treated with meloxicam, a cyclooxygenase-2 (COX-2) selective inhibitor. Between 2003 and 2012, consecutive 31 patients with extraabdominal, sporadic DTs were prospectively treated with meloxicam as a systemic medical therapy. Immunohistochemistry was performed on formalin-fixed material to quantify the nuclear expression of ß-catenin and Ki-67, and cytoplasmic expression of COX-2. All clinicopathological characteristics including the intensity of immunohistochemical staining were analyzed with respect to their prognostic value for meloxicam treatment. Of the 31 patients with meloxicam treatment, there was 1 with complete remission (CR), 7 with partial remission (PR), 12 with stable disease (SD), and 11 with progressive disease (PD). Higher nuclear expression of ß-catenin was significantly associated with a poor response (PD/SD) (p = 0.017). The positivity of COX-2 and Ki-67 and none of the other clinical variables were associated with prognosis. The nuclear expression of ß-catenin can predict the efficacy of meloxicam treatment for patients with sporadic DTs.

Suppression of hyaluronan synthesis alleviates inflammatory responses in murine arthritis and in human rheumatoid synovial fibroblasts.

OBJECTIVE: To clarify the roles of hyaluronan (HA) in joint inflammation and the process of joint destruction, using 4-methylumbelliferone (4-MU), an inhibitor of HA synthesis, in a mouse model of collagen-induced arthritis (CIA) and in a monolayer culture of fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis. METHODS: DAB/1J mice were immunized with type II collagen. The effects of 4-MU were evaluated by the physiologic arthritis score, paw swelling, the histologic arthritis score, and expression of matrix metalloproteinase 3 (MMP-3) and MMP-13 in chondrocytes and synovial tissue. In vitro, the effect of 4-MU on messenger RNA and protein expression of MMP-1 and MMP-3 was determined. The effects of 4-MU on HA deposition and on serum/medium concentrations of HA were analyzed using biotinylated HA binding protein staining and an HA binding assay, respectively. RESULTS: Treatment with 4-MU in mice with CIA dramatically decreased the severity of arthritis (based on the arthritis score), paw thickness, and histopathologic changes. MMP-3 and MMP-13 expression in chondrocytes and synovial cells was significantly inhibited by 4-MU in vivo. Treatment with 4-MU also inhibited MMP-1 and MMP-3 expression in tumor necrosis factor α-stimulated FLS, in a dose-dependent manner. The 4-MU-induced decreases in the serum HA concentration in mice with CIA and in "medium" and "pericellular" HA concentrations in cultured FLS support the contention that the inhibitory mechanism of 4-MU is mediated by HA suppression. CONCLUSION: Reduced disease activity induced by 4-MU in mice with CIA revealed HA to be a crucial regulator in the course of arthritis. Therefore, 4-MU is a potential therapeutic agent in arthritis, and its inhibitory mechanism is possibly mediated by suppression of HA synthesis.

Multiple primary malignancies in elderly patients with high-grade soft tissue sarcoma.

BACKGROUND: Several previous reports have described multiple cancers with regard to epithelial tumors, but few reports have focused on multiple primary malignancies including soft tissue sarcomas (STS). METHODS: The purpose of this study was to analyze the clinical features of patients with high-grade STS with multiple malignancies and possible clinical problems, compared with those with STS as a single malignancy, focusing on elderly patients. This study enrolled 107 patients aged 65 years or over with high-grade STS. RESULTS: Eighty-four patients (79 %) had sarcomas only (S group), and 23 (21 %) had multiple primary malignancies (M group). STS preceded carcinoma in 10 patients, and carcinoma preceded STS in 13. In 7 patients (30 %), the interval between the first and second malignancy was less than a year. Of 7 patients who received treatment for sarcoma and carcinoma at the same time, the presence of other malignancies had an impact on determination of the treatment modality in 5 patients. The overall survival rate at 5 years was higher in M group (79 %) than in S group (69 %), although this difference was not significant (P = 0.095). CONCLUSIONS: This study demonstrates that the presence of multiple malignancies was not correlated with a poor prognosis, and was actually associated with a better prognosis in elderly patients with STS. Physicians should be aware of the possible occurrence of a second malignancy, and on occasion the treatment modalities and their logistical aspects need to be well organized and carefully selected for patients with ongoing multiple malignancies.

Clinical factors affecting pathological fracture and healing of unicameral bone cysts.

BACKGROUND: Unicameral bone cyst (UBC) is the most common benign lytic bone lesion seen in children. The aim of this study is to investigate clinical factors affecting pathological fracture and healing of UBC. METHODS: We retrospectively reviewed 155 UBC patients who consulted Nagoya musculoskeletal oncology group hospitals in Japan. Sixty of the 155 patients had pathological fracture at presentation. Of 141 patients with follow-up periods exceeding 6 months, 77 were followed conservatively and 64 treated by surgery. RESULTS: The fracture risk was significantly higher in the humerus than other bones. In multivariate analysis, ballooning of bone, cyst in long bone, male sex, thin cortical thickness and multilocular cyst were significant adverse prognostic factors for pathological fractures at presentation. The healing rates were 30% and 83% with observation and surgery, respectively. Multivariate analysis revealed that fracture at presentation and history of biopsy were good prognostic factors for healing of UBC in patients under observation. CONCLUSION: The present results suggest that mechanical disruption of UBC such as fracture and biopsy promotes healing, and thus watchful waiting is indicated in these patients, whereas patients with poor prognostic factors for fractures should be considered for surgery.

Osteoarthritic change is delayed in a Ctsk-knockout mouse model of osteoarthritis.

OBJECTIVE: Several studies have shown that cathepsin K (CTK) is overexpressed in osteoarthritic (OA) cartilage and subchondral bone. However, it has not been well established whether CTK expression is harmful or beneficial. We undertook this study to investigate the direct involvement of CTK in OA development using Ctsk-knockout (Ctsk(-/-)) mice in a joint instability-induced model of OA. METHODS: We analyzed the natural course of the phenotype of 25-week-old Ctsk(-/-) mice. OA development was evaluated with a modified Mankin histologic score up to 8 weeks after surgery was performed to destabilize the knee in Ctsk(-/-) and Ctsk(+/+) mice. Histologic analysis was used to evaluate expression of CTK, matrix metalloproteinase 13 (MMP-13), ADAMTS-5, and tartrate-resistant acid phosphatase (TRAP) proteins in chondrocytes, synovial cells, and osteoclasts. Bone architecture was analyzed by histomorphometry. RESULTS: Bone mineral content and bone volume were higher in Ctsk(-/-) mice at 25 weeks, whereas OA did not develop spontaneously in either Ctsk(-/-) or Ctsk(+/+) mice. In a model of destabilization-induced OA, OA progression was significantly delayed in Ctsk(-/-) mice. CTK was overexpressed in chondrocytes and synovial cells of knee joints developing OA in Ctsk(+/+) mice. MMP-13 and ADAMTS-5 were less strongly expressed in chondrocytes of Ctsk(-/-) mice, and MMP-13 was less strongly expressed in synovial cells. TRAP-positive osteoclasts were overexpressed in Ctsk(-/-) mice. CONCLUSION: These results indicate that CTK plays crucial direct roles in the early to intermediate stage of OA development. CTK-positive chondrocytes and synovial cells may be a possible target to prevent disease progression in OA.

Metastasis of osteosarcoma to stomach made clinically evident by hematemesis: a case report.

BACKGROUND: Gastric metastasis from osteosarcoma is very rare and its clinical features are not well recognized. CASE PRESENTATION: A 73-year-old man was diagnosed with osteosarcoma and treated with four cycles of preoperative chemotherapy with ifosfamide and doxorubicin followed by wide resection. Two cycles of postoperative chemotherapy with ifosfamide and doxorubicin and ten cycles of chemotherapy with carboplatin and etoposide were administered. Eleven months after the surgery, he vomited fresh blood. Unusual progression of anemia was observed with the hematemesis. A biopsy was performed by gastrointestinal endoscopy, and the stomach tumor was diagnosed as metastasis of osteosarcoma. CONCLUSIONS: Even though gastric metastasis from osteosarcoma is very rare, all three previous reports and our case showed the presence of ulcer on the surface of the gastric lesion. We should consider the possibility of gastric metastasis in patients with osteosarcoma in whom progression of anemia or gastric hemorrhage is observed.

Inhibition of hyaluronan synthesis in breast cancer cells by 4-methylumbelliferone suppresses tumorigenicity in vitro and metastatic lesions of bone in vivo.

Hyaluronan (HA) has been shown to play crucial roles in the tumorigenicity of malignant tumors. Previous studies demonstrated that inhibition of HA suppressed the tumorigenicity of various malignant tumors including breast cancer. 4-methylumbelliferone (MU) has been reported to inhibit HA synthesis in several cell types. However, few studies have focused on the effects of HA inhibition in breast cancer cells by MU, nor the effects on bone metastasis. We hypothesized that MU would suppress the progression of bone metastasis via inhibition of HA synthesis. Here, we investigated the effects of MU on HA expression in MDA-MB-231 breast cancer cell line in addition to their tumorigenicity in vitro and in vivo. HAS2 mRNA expression was downregulated after 6 and 24 hr treatment with MU. Quantitative analysis of HA revealed that MU significantly inhibited the intracellular and cell surface HA. MU significantly inhibited cell growth and induced apoptosis as determined by cell proliferation and TUNEL assays, respectively. Phosphorylation of Akt was suppressed after 12 and 24 hr treatment with MU. MU treatment also inhibited cell motility as well as cell invasiveness. MU also inhibited cell growth and motility in murine fibroblast cell line NIH3T3. In vivo, administration of MU inhibited the expansion of osteolytic lesions on soft X-rays in mouse breast cancer xenograft models. HA accumulation in bone metastatic lesions was perturbed peripherally. These data suggest that MU might be a therapeutic candidate for bone metastasis of breast cancer via suppression of HA synthesis and accumulation.

Versican V1 isoform regulates cell-associated matrix formation and cell behavior differentially from aggrecan in Swarm rat chondrosarcoma cells.

Versican, a large chondroitin sulfate proteoglycan that binds hyaluronan and is composed of large extracellular matrix aggregates, has been shown to correlate with tumor progression. No studies have examined the roles of versican in chondrosarcoma nor compared them to those of aggrecan. In clinical specimens of human chondromatous tumors, versican expression was significantly increased in malignant tumors, moreover, as the tumor grade increased. To clarify the roles of versican in chondrosarcoma, versican splicing variant 1, variant 3 or only GFP was stably transfected to Swarm rat chondrosarcoma cells with Trap-In System. Forced expression of versican V1 isoform in Swarm rat chondrosarcoma cells induced a marked increase of cell-associated matrix compared to V3-, GFP- transfected or RCS cells. Versican was immunolocalized in a fashion similar to that of hyaluronan and more diffusively than aggrecan. Anchor-dependent and -independent growth was not affected by versican isoform expression, whereas cell motility and migration were significantly enhanced by V1 isoform transfection. Tumors formed in vivo with V1-transfected cells exhibited more myxomatous area and included more spindle shaped cells. These results support the concept that versican has the capacity to form more extensive cell-associated matrix than aggrecan, and the prominent matrix formation alters the cell behavior of chondrosarcoma more aggressively. These observations suggest that versican expression may serve as a marker of tumor grade determination in chondrosarcoma and possibly help to decide on therapeutic targets in higher grades of chondrosarcoma.

Giant cell tumor of bone arising in long bones possibly originates from the metaphyseal region.

Giant cell tumor of bone (GCTB) is a primary benign bone tumor with a locally aggressive character. Definitive descriptions of the site of origin for this type of tumor are not available. The aim of the present study was to evaluate the site of origin of GCTB of long bones with regards to epiphyseal lines by means of radiographic examination. For that purpose, plain X-ray scans of 71 GCTBs arising in long bones were retrospectively reviewed. The tumor locations were the distal femur in 31 cases, proximal femur in 11 cases, proximal tibia in 13 cases, distal radius in 6 cases, proximal humerus in 5 cases and proximal fibula in 5 cases. The vertical center (VC) of the tumor was determined with X-ray anteroposterior view, and the correlation between the VC and the epiphyseal line, and between the distance from the epiphyseal line to the VC and tumor area or volume were analyzed using a regression model equation based on scatter plot diagrams. The VC of the tumor was located in the metaphyseal region in 57 cases, in the epiphyseal line in 11 cases and in the epiphyseal region in 3 cases. In cases of GCTB located in the distal femur or proximal tibia, significant correlations between the distance from the VC to the epiphyseal line and tumor area or volume were identified. The site of origin of GCTB was estimated to be located in the metaphyseal region. GCTB often occurs in mature patients, which renders it challenging to estimate the true site of origin of this lesion, since the metaphyseal line has disappeared in mature patients. The results of the present study suggest that GCTB possibly originates in the metaphyseal region.

Association of short duration from initial symptoms to specialist consultation with poor survival in soft-tissue sarcomas.

INTRODUCTION: The association of symptom duration with survival remains controversial in soft-tissue sarcoma (STS). MATERIALS AND METHODS: We determined whether the length from initial symptoms to specialist consultation affects prognosis in STSs. We retrospectively reviewed 152 primary STS patients (with 142 non-small round cell sarcomas) who consulted our specialist hospital. The factors that affected the length of the period from the initial symptoms to specialist consultation and the length of the delay at the clinic before specialist hospital referral were investigated. The relation between the length of the period from symptom onset and overall survival was also analyzed. RESULTS: Unplanned excision and superficial tumor were significantly associated with increasing duration from the initial symptoms to specialist hospital referral. Multivariate analysis revealed that tumors over 5 cm (P=0.002 and 0.005) and symptoms within 6 months (P=0.017 and 0.016) were independent poor prognostic factors of overall survival among the pretreatment factors when analyzing all and non-small round cell STSs. CONCLUSIONS: This is a first report to show the independent prognostic role of symptom duration in STSs on multivariate analysis. Considering the impact of symptom duration on survival in these heterogenous tumors, careful follow-up and consideration of treatment are necessary for patients with short symptom duration.

CTNNB1 S45F mutation predicts poor efficacy of meloxicam treatment for desmoid tumors: a pilot study.

We hypothesized that patterns of CTNNB1 (ß-catenin) mutations would affect the outcome of conservative therapy in patients with desmoid tumors. This study aimed to determine the significance of CTNNB1 (ß-catenin) mutations in predicting the treatment outcome in patients with desmoid tumors treated with meloxicam, a cyclooxygenase-2 (COX-2) selective inhibitor. Between 2003 and 2012, consecutive thirty-three patients with extra-peritoneal sporadic desmoid tumors were prospectively treated with meloxicam as the initial systemic medical therapy. The efficacy of meloxicam was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST). DNA was isolated from frozen tissue or formalin-fixed materials. CTNNB1 mutation analysis was performed by direct sequencing. Positivity of nuclear ß-catenin staining by immunohistochemistry was compared with the status of CTNNB1 mutations. The correlation between the efficacy of meloxicam treatment and status of CTNNB1 mutations was analyzed. Of the 33 patients with meloxicam treatment, one showed complete remission (CR), 7 partial remission (PR), 12 stable disease (SD), and 13 progressive disease (PD). The following 3 point mutations were identified in 21 of the 33 cases (64%): T41A (16 cases), S45F (4 cases) and S45P (one case). The nuclear expression of ß-catenin correlated significantly with CTNNB1 mutation status (p = 0.035); all four cases with S45F mutation exhibited strong nuclear expression of ß-catenin. S45F mutation was significantly associated with a poor response (all cases; PD) (p = 0.017), whereas the other mutations had no impact on efficacy. The CTNNB1 mutation status was of significant prognostic value for meloxicam treatment in patients with sporadic desmoid tumors.

Neoadjuvant and adjuvant chemotherapy with doxorubicin and ifosfamide for bone sarcomas in adult and older patients.

The present study investigated the safety and efficacy of neoadjuvant and adjuvant chemotherapy with doxorubicin and ifosfamide for bone sarcoma in adult and older patients. A total of 18 consecutive patients with bone sarcoma (American Joint Committee on Cancer stage II in 14 patients and stage IV in four) treated with neoadjuvant and adjuvant chemotherapy at Nagoya Musculoskeletal Oncology Group hospitals in Japan between 2004 and 2011 were reviewed. The treatment efficacy and side-effects were evaluated. The responses to neoadjuvant chemotherapy were stable disease in 11 patients and progressive disease in three. Among the 12 evaluable patients, there were five with ≥90% tumor necrosis. The estimated overall survival (OS) rate at five years for the patients without metastasis prior to treatment was 56%. Major grade 3 or 4 side-effects included leukopenia in 14 cases, anemia in seven, thrombocytopenia in three, nausea in two and febrile neutropenia in two. One patient discontinued chemotherapy due to a temporarily depressed level of consciousness with arrhythmia (grade 2). The estimated five-year OS rate in this study was acceptable in patients without metastasis prior to treatment. A better coordinated prospective study of this combination regimen for older patients with bone sarcoma will be required to clarify its efficacy and tolerability.

Hyaluronan expression as a significant prognostic factor in patients with malignant peripheral nerve sheath tumors.

Hyaluronan (HA) regulates malignant tumor growth, invasion, and metastasis. However, few studies have focused on the roles of HA in tumorigenicity in malignant peripheral nerve sheath tumors (MPNST). In this study, we sought to clarify the prognostic value of HA in patients with MPNST. Specimens obtained from 15 patients with neurofibroma and 30 with MPNST were subjected to HA staining and scored as three grades. Protein expressions of HA synthase 1-3 were examined in the 22 MPNST tissue samples available. Statistically higher HA positivity was observed in MPNST as compared with neurofibroma (P = 0.020). The univariate analysis revealed that increased HA expression, age, neurofibromatosis type 1 (NF1) status, large tumor size, and histological grade were significantly associated with reduced overall survival of patients with MPNST; while increased HA expression, NF1 status, tumor size, and histological grade were correlated with disease-free survival. However, HA synthase 1-3 expression related to neither overall survival nor disease-free survival of these patients. In multivariate analysis, large tumor size (P = 0.022) was an independent prognostic factor for overall survival, and HA expression (P = 0.028) and tumor size (P = 0.002) were independent prognostic factors for disease-free survival. Statistically higher levels of HA in the human MPNST cells were observed compared with neurofibroma cells in vitro. Our results demonstrate that HA expression can be a useful marker in differentiating MPNST from neurofibroma, and in identifying patients with a poor prognosis. Hyaluronan-targeting therapy for patients with MPNST may have potential as a therapeutic tool.

Hyaluronan synthesis inhibitor supplements the inhibitory effects of zoledronic acid on bone metastasis of lung cancer.

Hyaluronan is known to have pivotal roles in the growth, migration and invasion of malignant tumors. Bone metastases are critical lesions greatly impairing the quality of patients with malignancies. We investigated whether hyaluronan synthesis inhibitor supplements the inhibitory effects of zoledronic acid, which is a conventional therapeutic agent for bone metastasis. We examined the effects of methylumbelliferone, an inhibitor of hyaluronan synthesis and/or ZA on the tumorigenicity of one murine lung carcinoma and two human (A549, SK-MES-1) lung cancer cell lines in vitro. The interaction between methylumbelliferone and zoledronic acid was analyzed using Calcucyn software. With a murine bone metastasis model of lung cancer in vivo, we investigated the inhibitory effects and interaction of the two drugs on the progression of metastatic bone lesions. Methylumbelliferone or zoledronic acid treatment individually suppressed proliferation, migration and invasion of 3 cell lines, and combination treatment showed synergistic effects. Although methylumbelliferone as a single agent did not enhance apoptotic activity, it showed additive effects on apoptotic activity to those of zoledronic acid. Co-localization of CD44 and ezrin, which might be a pathway of hyaluronan signaling, was abrogated by methylumbelliferone treatment. Combination therapy showed additive inhibitory effects on metastatic bone lesions in vivo, which paralleled the inhibition of hyaluronan accumulation by methylumbelliferone, and inhibition of osteoclastogenesis. Although the detailed mechanisms underlying the synergistic or additive inhibitory effects of these two drugs should be further analyzed, inhibition of hyaluronan synthesis by methylumbelliferone is a promising novel therapeutic candidate for bone metastasis of lung cancer in addition to zoledronic acid.

Therapeutic potential of hyaluronan oligosaccharides for bone metastasis of breast cancer.

Hyaluronan (HA) oligosaccharides were reported to have suppressive effects on various malignant tumors via disruption of receptor HA interactions. However, no studies have focused on the effects of HA oligosaccharides on bone metastasis of breast cancer. In this study, we clarified the effective size of HA oligosaccharides required to inhibit cell growth in the highly invasive breast cancer cell line, MDA-MB-231 cells. Based on the results of cell growth assay, we subsequently analyzed the effects of HA tetrasaccharides, HA decasaccharides, and high molecular weight HA on the other breast cancer cell behaviors in vitro and breast cancer bone metastasis in vivo. HA decasaccharides significantly inhibited cell growth, motility, and invasion, whereas tetrasaccharides did not. HAS2 mRNA expression was altered after the treatment with both tetrasaccharides and decasaccharides. Phosphorylation of Akt was suppressed after 1 h treatment with HA decasaccharides, and the effect was partially reversed by anti-CD44 monoclonal antibody. In vivo, local application of HA decasaccharides inhibited the expansion of osteolytic lesions in tibia on soft X-rays using mouse bone metastasis model of breast cancer. Histological analysis revealed HA accumulation in bone metastatic lesions was perturbed by decasaccharides. These results suggest that HA oligosaccharides suppressed progression of bone metastasis in breast cancer via interruption of endogenous HA-CD44 interaction, and as such, can be a novel therapeutic candidate to limit bone metastasis of breast cancer.