Kunihiro Asanuma

Clinical significance of pretreatment serum C-reactive protein level in soft tissue sarcoma.

The aim of this study was to determine whether circulating C‐reactive protein (CRP) levels before treatment predict the overall survival and disease‐free survival in soft tissue sarcoma patients.

A novel hyperthermia treatment for bone metastases using magnetic materials.

Patients with bone metastases in the extremities sometimes require surgical intervention to prevent deterioration of quality of life due to a pathological fracture. The use of localized radiotherapy combined with surgical reinforcement has been a gold standard for the treatment of bone metastases. However, radiotherapy sometimes induces soft tissue damage, including muscle induration and joint contracture. Moreover, cancer cells are not always radiosensitive. Hyperthermia has been studied since the 1940s using an experimental animal model to treat various types of advanced cancer, and studies have now reached the stage of clinical application, especially in conjunction with radiotherapy or chemotherapy. Nevertheless, bone metastases have several special properties which discourage oncologists from developing hyperthermic therapeutic strategies. First, the bone is located deep in the body, and has low thermal conductivity due to the thickness of cortical bone and the highly vascularized medulla. To address these issues, we developed new hyperthermic strategies which generate heat using magnetic materials under an alternating electromagnetic field, and started clinical application of this treatment modality. The purpose of this review is to summarize the latest studies on hyperthermic treatment in the field of musculoskeletal tumors, and to introduce the treatment strategy employing our novel hyperthermia approach.

Regulation of carcinoma cell invasion by protein C inhibitor whose expression is decreased in renal cell carcinoma

Protein C inhibitor (PCI), a member of the serine protease inhibitor family, is produced in various human tissues, including the liver, kidney and testis. In addition to inhibiting the anticoagulant protein C pathway, PCI also inhibits urinary plasminogen activator (uPA), which is a well‐known mediator of tumor cell invasion. In the present study, to clarify the biologic significance of PCI in the kidney, we compared the expression of PCI between human renal cell carcinoma (RCC) tissue and nontumor kidney tissue. The PCI antigen level in RCC tissue was found to be significantly lower than in nontumor kidney tissue, and expression of PCI mRNA was detected in normal renal proximal tubular epithelial cells (RPTEC), but not in RCC or in an RCC cell line (Caki‐1 cells). No differences were detected between the nucleotide sequence of the major cis‐elements in the promoter region of the PCI gene from nontumor kidney and RCC tissues, RPTEC and Caki‐1 cells, an RPTEC‐derived RCC cell line. The in vitro invasiveness of Caki‐1 cells transfected with a PCI expression vector was significantly decreased compared to mock‐transfected Caki‐1 cells, and it was blocked in the presence of anti‐PCI antibody. Since PCI itself did not affect the proliferation rate of Caki‐1 cells or cell expression of uPA in vitro, the effect of uPA, PCI, heat‐inactivated PCI and plasminogen activator inhibitor (PAI)‐1 on the invasive potential of cultured RCC cells was evaluated. The in vitro invasiveness of Caki‐1 cells, which express uPA, was significantly enhanced by the addition of uPA, and it was inhibited by anti‐uPA antibody, PCI and PAI‐1, but not by heat‐inactivated PCI. In addition, uPA activity was significantly decreased and uPA‐PCI complex level was significantly increased in the culture medium of PCI expression vector‐transfected Caki‐1 cells as compared to mock‐transfected Caki‐1 cells. These findings strongly suggest that PCI regulates the invasive potential of RCC cells by inhibiting uPA secreted by these cells. The results of our study suggest that PCI might be a potential therapeutic agent for inhibiting renal tumor invasion.

Protein C inhibitor inhibits breast cancer cell growth, metastasis and angiogenesis independently of its protease inhibitory activity

Protein C inhibitor (PCI) regulates the anticoagulant protein C pathway and also inhibits urinary plasminogen activator (uPA), a mediator of tumor cell invasion. In the present study, we evaluated the effect of human PCI and its inactive derivatives on tumor growth and metastasis of human breast cancer (MDA‐231) cells, and on angiogenesis in vivo. The invasiveness of MDA‐231 cells was inhibited by recombinant intact PCI, but not by reactive site‐modified PCI (R354APCI) or by the N‐terminal fragment of protease‐cleaved PCI (NTPCI). The in vitro invasiveness of MDA‐231 cells expressing intact PCI (MDA‐PCI) was significantly decreased as compared to MDA‐231 cells expressing R354APCI (MDA‐R354APCI) or NTPCI (MDA‐NTPCI). Further, in vivo growth and metastatic potential of MDA‐PCI, MDA‐R354APCI and MDA‐NTPCI cells in severe combined immunodeficient (SCID) mice were significantly decreased as compared to MDA‐Mock cells. Angiogenesis was also significantly decreased in Matrigel implant containing MDA‐PCI, MDA‐R354APCI or MDA‐NTPCI cells as compared to that containing MDA‐Mock cells. In vivo angiogenesis in rat cornea and in vitro tube formation were also inhibited by recombinant intact PCI, R354APCI and NTPCI. Furthermore, the anti‐angiogenic activity of PCI was strong as cleaved antithrombin (AT), and slightly stronger than that of plasminogen activator inhibitor (PAI)‐1 and pigment epithelium‐derived factor (PEDF). Overall, this study showed that, in addition to a reactive site‐dependent mechanism, PCI may also regulate tumor growth and metastasis independently of its protease inhibitory activity by inhibiting angiogenesis.

Thrombin Inhibitor, Argatroban, Prevents Tumor Cell Migration and Bone Metastasis

It is well known that malignant cells show procoagulant activity, which is associated with their metastatic potential. Thrombin, the key enzyme of the blood coagulation system, is generated around tumor cells, promoting the migration and metastasis of tumor cells. In this study, we evaluated the effect of argatroban, a specific thrombin inhibitor, on the migration and metastasis of B16BL6 melanoma cells. In vitro argatroban dose-dependently inhibited cell migration, the maximum inhibition being observed in the presence of 10 µM argatroban (p < 0.0001). In order to investigate the antimetastatic effect of the thrombin inhibitor, we used an animal model that we have reported previously. C57BL6 mice which had received a bone (femur or tibia) transplanted into the dorsal subcutis were injected with B16 melanoma cells into the left heart ventricle. Intraperitoneal injection of argatroban (9 mg/kg/day for 4 weeks) significantly reduced the number of limbs with metastatic lesions as compared to a placebo (p < 0.05). These results suggest that argatroban was associated with reduced melanoma metastases by inhibiting cell migration. Our results showed that argatroban is effective for treatment of bone metastasis.

The symptom-to-diagnosis delay in soft tissue sarcoma influence the overall survival and the development of distant metastasis.

There are very few reports regarding the impact of the symptom that caused patients to consult a doctor and the symptom‐to‐diagnosis delay on survival for soft tissue sarcoma patients. The purpose of this study is to investigate whether symptom‐treatment delay are associated with the presence of metastasis at diagnosis, overall survival and distant metastasis‐free survival in primary soft tissue sarcomas.

Characterization of a novel human protein C inhibitor (PCI) gene transgenic mouse useful for studying the role of PCI in physiological and pathological conditions.

Summary.  In humans, protein C inhibitor (PCI) is expressed in various tissues and present in many body fluids including plasma and seminal fluid. In rodents, PCI is expressed in reproductive organs only and is absent in plasma. In this study, we characterized the tissue expression and physiological role of PCI in novel human PCI gene transgenic (TG) mice. Northern blot and immunohistochemical analyses demonstrated that human PCI is expressed in liver hepatocytes, renal epithelial cells as well as heart, brain and reproductive organs of the TG mice. This PCI tissue distribution is similar to that found in humans. PCI in plasma of TG mice showed the same immunological and functional properties as human plasma PCI. Next, we evaluated the effect of PCI on coagulation, inflammation and tissue damage in lipopolysaccharide‐treated TG mice. The results suggested that PCI efficiently inhibits not only the anticoagulant and anti‐inflammatory activities of exogenously injected human activated protein C (APC) but also that of endogenously produced APC in mice with endotoxemia. These findings suggest that PCI exerts a procoagulant and proinflammatory effect by inhibiting APC. We believe our results also show how useful these TG mice may be for assessing the therapeutic effect of human APC in vivo and for evaluating the role of PCI in human physiological and pathological conditions.

The adverse effect of an unplanned surgical excision of foot soft tissue sarcoma

BackgroundMalignant soft tissue tumors of the foot are extremely rare and thus can be prematurely excised without appropriate preoperative evaluation. The present study compares adverse effects between unplanned and planned surgical excisions.MethodsWe retrospectively reviewed the clinical records, radiographs, pathology reports and pathological specimens of 14 consecutive patients with soft tissue sarcoma of the foot among 592 with sarcomas between 1973 and 2009. We then compared the incidence and clinical outcomes after unplanned (UT; n = 5) and planned (PT; n = 9) surgical excisions of foot sarcomas.ResultsThe most frequent diagnosis was synovial sarcoma (n = 4; 28.6%). The overall 5-year survival rates of the PT and UT groups were 65.6% and 60.0%, respectively, and the event-free 5-year survival rates were 63.5% and 40.0%, respectively. Event-free and overall survival rates did not significantly differ between the two groups. However, tumors were significantly larger in the PT group than in the UT group (p < 0.05).ConclusionsUnplanned resection lead to a relatively worse prognosis and a likelihood of recurrence despite additional resections. We recommend that soft tumors of the foot should only be excised after appropriate preoperative evaluation regardless of the size of the tumor.

Comparison of three different anti-Xa assays in major orthopedic surgery patients treated with fondaparinux

Anti-Xa assays are useful for monitoring the effects of selective anti-Xa drugs, such as fondaparinux, in the prophylaxis of deep vein thrombosis. In the present study, anti-Xa activity was measured using three different assays, Testzym® Heparin S, STA®-Liquid Anti-Xa and HemosIL® Liquid Heparin. Anti-Xa activity in each assay gradually increased from day one after administration to day eight, and still remained on day 15. Although there were significant differences in anti-Xa activity among the three assays, the activity showed significant correlation across assays. There were no significant differences in the anti-Xa activity between patients with and without DVT or between patients with and without massive bleeding on day one before and after administration, day four, day eight and day 15. Anti-Xa activity in each assay was weakly correlated with antithrombin (AT) activity. The AT activity in patients were significantly higher on days four, eight and 15 compared with day one before and after administration, suggesting that AT activity increases following the administration of fondaparinux. The three anti-Xa assay kits tested are useful for monitoring fondaparinux treatment in orthopedic surgery patients.

The value of the high-sensitivity modified Glasgow prognostic score in predicting the survival of patients with a soft-tissue sarcoma

The aim of this study was to determine whether the high-sensitivity modified Glasgow prognostic score (Hs-mGPS) could predict the disease-specific survival and oncological outcome in adult patients with non-metastatic soft-tissue sarcoma before treatment. A total of 139 patients treated between 2001 and 2012 were retrospectively reviewed. The Hs-mGPS varied between 0 and 2. Patients with a score of 2 had a poorer disease-specific survival than patients with a score of 0 (p < 0.001). The estimated five-year rate of disease-specific survival for those with a score of 2 was 0%, compared with 85.4% (95% CI 77.3 to 93.5) for those with a score of 0. Those with a score of 2 also had a poorer disease-specific survival than those with a score of 1 (75.3%, 95% CI 55.8 to 94.8; p < 0.001). Patients with a score of 2 also had a poorer event-free rate than those with a score of 0 (p < 0.001). Those with a score of 2 also had a poorer event-free survival than did those with a score of 1 (p = 0.03). A multivariate analysis showed that the Hs-mGPS remained an independent predictor of survival and recurrence. The Hs-mGPS could be a useful prognostic marker in patients with a soft-tissue sarcoma.