Identification of unapproved orthopedic regenerative medicine: Usefulness of the Act on Safety of Regenerative Medicine

In Japan, the Act on Safety of Regenerative Medicine regulates unapproved regenerative medicine. Other nations market regenerative medicine products, bypassing regulatory approval. To identify unapproved orthopedic regenerative medicine, we have used data based on the Act. Platelet-rich plasma was often used. The common target was the knee. Prices averaged $2,490.

Remote audit practice for inspection of structural and equipment standards for cell processing facilities under the act on the safety of regenerative medicine in Japan

Introduction

The Act on the Safety of Regenerative Medicine enforced in Japan in 2014, regulates the manufacture of cellular processed products. However, with regards to the manufacturing facilities at medical institutions, only the submission of necessary documents is required for a license, and the need for third-party inspection has been highlighted. Remote activities are becoming more prominent with the spread of the Severe Acute Respiratory Syndrome Coronavirus 2 infection; therefore, the current assessment of compliance with structural facility standards was conducted remotely.

Methods

The entire process, including start-up meetings, preparation of the survey schedule, submission and review of preliminary materials, audits, and reporting of results, was conducted via e-mail and web conferencing systems. The survey was conducted remotely, to minimize the risk of contamination of the cell processing facility (CPF) and reduce the burden on surveyors, while contributing to the establishment of suitable structural facilities by identifying and highlighting the areas or items that were considered to be non-compliant with the regulations. The series of audits were completed in ten weeks, with a period of six weeks between the start-up meeting and the audit implementation. The audit was completed in approximately 3 h on the day of the inspection.

Results

The audit results were delivered in the report, with four items requiring improvement and several other recommended items listed as non-conformities.

Conclusions

We believe that this remote method allows the effective inspection of regenerative medicine manufacturing facilities and assessment of more cell culture processing facilities than the current in-person audit method, with limited human resources.

Safety and immunogenicity of BK-SE36/CpG malaria vaccine in healthy Burkinabe adults and children: a phase 1b randomised, controlled, double-blinded, age de-escalation trial

Background

BK-SE36/CpG is a recombinant blood-stage malaria vaccine candidate based on the N-terminal Plasmodium falciparum serine repeat antigen5 (SE36), adsorbed to aluminium hydroxide gel and reconstituted, prior to administration, with synthetic oligodeoxynucleotides bearing CpG motifs. In healthy Japanese adult males, BK-SE36/CpG was well tolerated. This study assessed its safety and immunogenicity in healthy malaria-exposed African adults and children.

Methods

A double-blind, randomised, controlled, age de-escalating clinical trial was conducted in an urban area of Ouagadougou, Burkina Faso. Healthy participants (n=135) aged 21-45 years (Cohort 1), 5-10 years (Cohort 2) and 12-24 months (Cohort 3) were randomised to receive three vaccine doses (Day 0, 28 and 112) of BK-SE36/CpG or rabies vaccine by intramuscular injection.

Results

One hundred thirty-four of 135 (99.2%) subjects received all three scheduled vaccine doses. Vaccinations were well tolerated with no related Grade 3 (severe) adverse events (AEs). Pain/limitation of limb movement, headache in adults and fever in younger children (all mild to moderate in intensity) were the most frequently observed local and systemic AEs. Eighty-three of BK-SE36/CpG (91%) recipients and 37 of control subjects (84%) had Grade 1/2 events within 28 days post vaccination. Events considered by the investigator to be vaccine related were experienced by 38% and 14% of subjects in BK-SE36/CpG and control arms, respectively. Throughout the trial, six Grade 3 events (in 4 subjects), not related to vaccination, were recorded in the BK-SE36/CpG arm: 5 events (in 3 subjects) within 28 days of vaccination. All serious adverse events (SAEs) (n=5) were due to severe malaria (52-226 days post vaccination) and not related to vaccination. In all cohorts, BK-SE36/CpG arm had higher antibody titres after Dose 3 than after Dose 2. Younger cohorts had stronger immune responses (12-24-month-old > 5-10 years-old > 21-45 years-old). Sera predominantly reacted to peptides that lie in intrinsically unstructured regions of SE36. In the control arm, there were no marked fold changes in antibody titres and participants' sera reacted poorly to all peptides spanning SE36.

Conclusion

BK-SE36/CpG was well-tolerated and immunogenic. These results pave the way for further proof-of-concept studies to demonstrate vaccine efficacy.

Clinical trial registration

https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=1921, PACTR201701001921166.

Homoharringtonine is a transdermal granular permeation enhancer

Although modulation of claudin-1-based tight junction (TJ) in stratum granulosum is an option for transdermal absorption of drugs, granular permeation enhancers have never been developed. We previously found that homoharringtonine (HHT), a natural alkanoid, weakened intestinal epithelial barrier with changing expression and cellular localization of TJ components such as claudin-1 and claudin-4. In the present study, we investigated whether HHT is an epidermal granular permeation enhancer. Treatment of normal human epidermal keratinocytes (NHEK) cells with HHT decreased claudin-1 and claudin-4 but not zonula occludens-1 and E-cadherin. HHT lowered TJ-integrity in NHEK cells, accompanied by permeation-enhancement of dextran (4 kDa) in a dose-dependent manner. Transdermal treatment of mice with HHT weakened epidermal barrier. HHT treatment enhanced transdermal absorption of dextran with a molecular mass of up to 10 kDa. Together, HHT may be a transdermal absorption enhancer.

A phase I dose-escalation, safety/tolerability, and preliminary efficacy study of the intratumoral administration of GEN0101 in patients with advanced melanoma

Despite recent advance in immunotherapy agents, safe new therapies that enhance the effects of immune checkpoint inhibitors are still required to develop. We previously demonstrated that hemagglutinating virus of Japan-envelope (HVJ-E) induced not only direct tumor cell death but also antitumor immunity through the activation of T and natural killer (NK) cells, thereafter, developed a manufacturing process of HVJ-E (GEN0101) for clinical use. We here performed a phase Ia clinical trial of intratumoral GEN0101 administration in six patients with stage IIIC or IV malignant melanoma. The primary aim was to evaluate the safety and tolerability of GEN0101, and the secondary aim was to examine the objective tumor response. Patients were separated into two groups (n = 3 each) and received a low dose of 30,000 and high dose of 60,000 mNAU of GEN0101. All patients completed a two-week follow-up evaluation without severe adverse events. The overall response rate was 33% (2 of 6), with 2 partial responses in the high-dose group and 2 with stable disease, and 2 with progressive disease in the low-dose group. Local complete or partial responses were observed in 11 of 18 (61%) target lesions. One patient demonstrated shrinkage of lung metastases after the treatment. The activity of NK cells and interferon-γ levels were increased in the circulation, indicating augmentation of antitumor immunity by GEN0101. This trial showed not only the safety and tolerability but also the significant antitumor effect of GEN0101, suggesting that GEN0101 might be a promising new drug for patients with advanced melanoma.

Impact of surgical resection on survival in patients with metastatic soft tissue sarcoma and comparison between synchronous and metachronous metastases

BACKGROUND

The role of local surgery in patients with metastatic soft tissue sarcoma (STS) remains unknown. The study aims to assess the clinical outcomes and impact of surgical resection on survival in patients with metastatic STS and elucidate the survival differences between synchronous and metachronous metastatic groups.

METHODS

Among the 272 patients with STS treated between 2000 and 2018, 84 with synchronous or metachronous metastasis were included. Associations between overall survival and primary tumor resection and metastasectomy were assessed using multivariate Cox regression analyses to adjust for baseline differences between surgically and non-surgically treated patients. Propensity score matching was applied to compare synchronous and metachronous metastasis.

RESULTS

Among the 84 patients included, 69 (82%) and 41 (49%) underwent primary tumor resection and metastasectomy, respectively. The 2- and 5-year overall survivals of all patients after first detection of metastasis were 51.1% and 24.4%, respectively. Multivariate analysis showed that size <8 cm, grade <3, and number of metastases <4 were associated with longer overall survival. After adjusting for baseline demographic and tumor characteristics, primary tumor resection and metastasectomy still had favorable effects on survival. Tumor subtypes, grade, and number of metastases differed significantly between synchronous and metachronous groups. However, after adjusting for these valuables, both groups exhibited comparable survival.

CONCLUSIONS

Approximately one fourth of the patients with metastatic STS survived for >5 years. Our results showed that surgical resection of primary tumors or metastatic lesions had favorable impact on survival even after adjusting for patient backgrounds, with comparable survival observed between those with synchronous and metachronous metastases.

First-in-human randomised trial and follow-up study of Plasmodium falciparum blood-stage malaria vaccine BK-SE36 with CpG-ODN(K3)

BACKGROUND

BK-SE36 is blood-stage malaria vaccine candidate that is undergoing clinical trials. Here, the safety and immunogenicity of BK-SE36 with a novel adjuvant, CpG-ODN(K3) (thus, BK-SE36/CpG) was assessed in a phase 1a trial in Japan.

METHODS

An investigator-initiated, randomised, single-blind, placebo-controlled, dose-escalation study was conducted at Osaka University Hospital with 26 healthy malaria naïve Japanese male adults. The trial was conducted in two stages: Stage/Group 1, half-dose (n = 7 for BK-SE36/CpG and n = 3 for control) and Stage/Group 2, full-dose (n = 11 for BK-SE36/CpG and n = 5 for control). There were two intramuscular vaccinations 21 days apart for both half-dose (0.5 ml: 50 µg SE36 + 500 µg aluminum + 500 µg K3) and full-dose (1.0 ml: 100 µg SE36 + 1000 µg aluminum + 1000 µg K3). A one-year follow-up was done to monitor changes in autoimmune markers and vaccine-induced antibody response.

RESULTS

BK-SE36/CpG was well tolerated. Vaccination site reactions were similar to those observed with BK-SE36. During the trial and follow-up period, no subject had clinical evidence of autoimmune disease. The full-dose group had significantly higher titres than the half-dose group (Student's t-test, p = 0.002) at 21 days post-second vaccination. Antibody titres remained above baseline values during 12 months of follow-up. The vaccine induced antibody was mostly composed of IgG1 and IgM, and recognised epitopes close to the polyserine region located in the middle of SE36.

CONCLUSIONS

BK-SE36/CpG has an acceptable safety profile. Use of CpG-ODN(K3) greatly enhanced immunogenicity in malaria naïve Japanese adults when compared to BK-SE36 alone. The utility of BK-SE36/CpG is currently under evaluation in a malaria endemic setting in West Africa.

TRIAL REGISTRATION

JMACCT Clinical Trial Registry JMA-IIA00109.

Intratumoral injection of hemagglutinating virus of Japan-envelope vector yielded an antitumor effect for advanced melanoma: a phase I/IIa clinical study

Hemagglutinating virus of Japan (HVJ; Sendai virus) is an RNA virus that has cell fusion activity. HVJ-envelope (HVJ-E) is a UV-irradiated HVJ particle that loses viral replication and protein synthesis activity but retains cell fusion activity. We recently reported that HVJ-E has antitumor effects on several types of tumors. Here, we describe the results of a first-in-human phase I/IIa study in patients with advanced melanoma, receiving intratumoral administration of HVJ-E. The primary aim was to evaluate the safety and tolerability of HVJ-E, and the secondary aim was to examine the objective tumor response and antitumor immunity. Six patients with stage IIIC or IV progressive malignant melanoma with skin or lymph metastasis were enrolled. Patients were separated into two groups (n = 3 each) and received low and high doses of HVJ-E. Five of the six patients completed 4 weeks of follow-up evaluation; one patient discontinued treatment owing to progressive disease. Complete or partial responses were observed in 3 of 6 (50%) injected target lesions, 7 of 15 (47%) noninjected target lesions, and 10 of 21 (48%) target lesions. Induction of antitumor immunity was observed: activation of natural killer cells, a marked increase in interferon-γ levels in the peripheral blood, and infiltration of cytotoxic T cells into both injected and noninjected tumor lesions. Thus, intratumoral injection of HVJ-E in advanced melanoma patients showed safety and tolerability with local regression of the tumor mediated by antitumor immunity. The results suggest that HVJ-E might be a new treatment approach in patients with advanced melanoma.

Pediatric drug development in Japan: Current issues and perspectives

The number of clinical trials in Japan that aim to obtain regulatory approval for new drugs and devices has increased for adults, but not children. The following reasons have been proposed for this discrepancy: the wide range of ages from newborns to adolescents, requirements for many drug formulations, the difficulties associated with obtaining consent, and less profit for companies. The processes required to obtain regulatory approval for drugs and devices, particularly in the pediatric field, differ among Japan, Europe, and the United States (US). While clinical trials are not necessarily required for the development of new drugs or obtaining additional indications in Japan, laws in Europe and the US require clinical trials on children for newly developed drugs; however, pharmaceutical companies are entitled to a 6-mo extension for a patent when pediatric data are added to the attached documents for clinical trials. We herein discuss the current status of and issues associated with pediatric drug development, including clinical trials, in Japan as well as future perspectives.

Eribulin Suppresses Clear Cell Sarcoma Growth by Inhibiting Cell Proliferation and Inducing Melanocytic Differentiation Both Directly and Via Vascular Remodeling

Clear cell sarcoma (CCS) is a rare but chemotherapy-resistant and often fatal high-grade soft-tissue sarcoma (STS) characterized by melanocytic differentiation under control of microphthalmia-associated transcription factor (MITF). Eribulin mesilate (eribulin) is a mechanistically unique microtubule inhibitor commonly used for STS treatment, particularly liposarcoma and leiomyosarcoma. In this study, we examined the antitumor efficacy of eribulin on four human CCS cell lines and two mouse xenograft models. Eribulin inhibited CCS cell proliferation by inducing cell-cycle arrest and apoptosis, shrunk CCS xenograft tumors, and increased tumor vessel density. Eribulin induced MITF protein upregulation and stimulated tumor cell melanocytic differentiation through ERK1/2 inactivation (a MITF negative regulator) in vitro and in vivo Moreover, tumor reoxygenation, probably caused by eribulin-induced vascular remodeling, attenuated cell growth and inhibited ERK1/2 activity, thereby upregulating MITF expression and promoting melanocytic differentiation. Finally, downregulation of MITF protein levels modestly debilitated the antiproliferative effect of eribulin on CCS cells. Taken together, eribulin suppresses CCS through inhibition of cell proliferation and promotion of tumor differentiation by acting both directly on tumor cells and indirectly through tumor reoxygenation.

Transplantation of autologous bone marrow-derived mesenchymal stem cells under arthroscopic surgery with microfracture versus microfracture alone for articular cartilage lesions in the knee: A multicenter prospective randomized control clinical trial

Introduction

To investigate the efficacy of the transplantation of autologous bone marrow-derived mesenchymal stem cells (BMSCs) under arthroscopy with microfracture (MFX) compared with microfracture alone.

Methods

Eleven patients with a symptomatic articular cartilage defect of the knee were included in the study. They were randomized to receive BMSCs with MFX (cell-T group, n=7) or MFX alone (control group, n=4). Clinical results were evaluated using International Knee Documentation committee (IKDC) knee evaluation questionnaires and the Knee Injury and Osteoarthritis Outcome Score (KOOS) before and 48 weeks after surgery. Quantitative and qualitative assessments of repair tissue were carried out at 48 weeks by T2 mapping of magnetic resonance images (MRIs) and the magnetic resonance observation of cartilage repair tissue (MOCART) scoring system with follow-up MRI.

Results

No significant differences between preoperative and postoperative IKDC and KOOS were observed in the cell-T or control group. However, forty-eight weeks after surgery, the cell-T group showed a trend for a greater KOOS QOL score compared with the control group (79.4 vs. 39.1, respectively; P=0.07). The T2 value did not differ significantly between the two groups, but the mean MOCART score was significantly higher in the cell-T group than in the control group (P=0.02).

Conclusions

Compared with MFX alone, BMSC transplantation with MFX resulted in better postoperative healing of the cartilage and subchondral bone as determined by the MOCART score. Clinically, BMSC transplantation with MFX gave a higher KOOS QOL score after 48 weeks.

•

This is the first prospective randomized clinical trial between BMSCs with MFX and MFX alone.

•

BMSCs with MFX showed a trend for a greater KOOS QOL score compared with MFX alone.

•

BMSCs with MFX resulted in better healing of the cartilage by the MOCART score.

Three-Dimensional Corrective Osteotomy for Malunited Fractures of the Upper Extremity Using Patient-Matched Instruments: A Prospective, Multicenter, Open-Label, Single-Arm Trial

BACKGROUND

Medical image processing has facilitated simulation of 3-dimensional (3-D) corrective osteotomy, and 3-D rapid prototyping technology has further enabled the manufacturing of patient-matched surgical guides and implants (patient-matched instruments, or PMIs). However, 3-D corrective osteotomy using these technologies has not been the standard procedure. We aimed to prospectively verify the efficacy and safety of PMIs in corrective osteotomy for deformities of the upper extremity.

METHODS

We enrolled 16 patients with a total of 17 bone deformities in the upper extremity. Eight patients had distal radial malunion; 5, distal humeral malunion; and 3, forearm diaphyseal malunion. All cases underwent 3-D corrective osteotomy with PMIs. The primary end point was the residual maximum deformity angle (MDA), which was calculated from 2 deformity angles-1 on the anteroposterior and 1 on the lateral postoperative radiograph. Secondary end points included the deformity angle on radiographs, 3-D error between the preoperative planning model and the postoperative result, range of motion, grip strength, pain measured with a visual analog scale (VAS), patient satisfaction, and Disabilities of the Arm, Shoulder and Hand (DASH) score.

RESULTS

The average MDA significantly improved from 25.5° preoperatively to 3.3° at the final follow-up (p < 0.001). The angular deformity was within 5° in all cases, except for 1 with distal radial malunion who had a higher angle on the anteroposterior radiograph. The error between the correction seen on the postoperative 3-D bone model and the planned correction was <1° and <1 mm. Flexion and extension of the wrist and pronation of the forearm of the patients treated for distal radial malunion improved significantly, and pronation improved for those treated for forearm diaphyseal malunion. The average VAS score, grip strength, and DASH score significantly improved as well. Of the 16 patients, 15 were very satisfied or satisfied with the outcomes.

CONCLUSIONS

Corrective osteotomy using PMIs achieved accurate correction and good functional recovery in the upper extremity. Although our study was limited to cases without any deformity on the contralateral side, 3-D corrective osteotomy using PMIs resolved treatment challenges for complex deformities in upper extremities.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Impact of non-thermal plasma surface modification on porous calcium hydroxyapatite ceramics for bone regeneration

In the physiochemical sciences, plasma is used to describe an ionized gas. Previous studies have implicated plasma surface treatment in the enhancement of hydrophilicity of implanted musculoskeletal reconstructive materials. Hydroxyapatite (HA) ceramics, widely used in bone tissue regeneration, have made great advancements to skeletal surgery. In the present study, we investigate the impact of low-pressure plasma on the interconnected porous calcium hydroxyapatite (IP-CHA) both in vitro and in vivo. Our results indicate that dielectric barrier discharge (DBD) plasma, when used with oxygen, can augment the hydrophilicity of non-porous HA surfaces and the osteoconductivity of the IP-CHA disc via increased water penetration of inner porous structures, as demonstrated through microfocus computed tomography (μCT) assay. In vivo implantation of plasma-treated IP-CHA displayed superior bone ingrowth than untreated IP-CHA. Though plasma-treated IP-CHA did not alter osteoblast cell proliferation, it accelerated osteogenic differentiation of seeded marrow mesenchymal stem cells. In vitro X-ray photoelectron spectroscopy (XPS) revealed that this plasma treatment increases levels of oxygen, rather than nitrogen, on the plasma-treated IP-CHA surface. These findings suggest that plasma treatment, an easy and simple processing, can significantly improve the osteoconductive potential of commonly used artificial bones such as IP-CHA. Further optimization of plasma treatment and longer-term follow-up of in vivo application are required toward its clinical application.

Time-Dependent Recovery of Human Synovial Membrane Mesenchymal Stem Cell Function After High-Dose Steroid Therapy: Case Report and Laboratory Study

BACKGROUND

The use of mesenchymal stem cells from various tissue sources to repair injured tissues has been explored over the past decade in large preclinical models and is now moving into the clinic.

PURPOSE

To report the case of a patient who exhibited compromised mesenchymal stem cell (MSC) function shortly after use of high-dose steroid to treat Bell's palsy, who recovered 7 weeks after therapy.

STUDY DESIGN

Case report and controlled laboratory study.

METHODS

A patient enrolled in a first-in-human clinical trial for autologous implantation of a scaffold-free tissue engineered construct (TEC) derived from synovial MSCs for chondral lesion repair had a week of high-dose steroid therapy for Bell's palsy. Synovial tissue was harvested for MSC preparation after a 3-week recovery period and again at 7 weeks after therapy.

RESULTS

The MSC proliferation rates and cell surface marker expression profiles from the 3-week sample met conditions for further processing. However, the cells failed to generate a functional TEC. In contrast, MSCs harvested at 7 weeks after steroid therapy were functional in this regard. Further in vitro studies with MSCs and steroids indicated that the effect of in vivo steroids was likely a direct effect of the drug on the MSCs.

CONCLUSION

This case suggests that MSCs are transiently compromised after high-dose steroid therapy and that careful consideration regarding timing of MSC harvest is critical.

CLINICAL RELEVANCE

The drug profiles of MSC donors and recipients must be carefully monitored to optimize opportunities to successfully repair damaged tissues.

Trabectedin is a promising antitumor agent potentially inducing melanocytic differentiation for clear cell sarcoma

Clear cell sarcoma is an aggressive soft tissue sarcoma and highly resistant to conventional chemotherapy and radiation therapy. This devastating disease is defined by EWSR1‐ATF1 fusion gene resulting from chromosomal translocation t(12;22)(q13;q12) and characterized by melanocytic differentiation. A marine‐derived antineoplastic agent, trabectedin, inhibits the growth of myxoid liposarcoma and Ewing sarcoma by causing adipogenic differentiation and neural differentiation, respectively. In this study, we examined the antitumor effects and mechanism of action of trabectedin on human clear cell sarcoma cell lines. We showed that trabectedin decreased the cell proliferation of five clear cell sarcoma cell lines in a dose‐dependent manner in vitro and reduced tumor growth of two mouse xenograft models. Flow cytometry and immunoblot analyses in vitro and immunohistochemical analysis in vivo revealed that trabectedin‐induced G2/M cell cycle arrest and apoptosis. Furthermore, trabectedin increased the expression of melanocytic differentiation markers along with downregulation of ERK activity in vitro and the rate of melanin‐positive cells in vivo. These results suggest that trabectedin has potent antitumor activity against clear cell sarcoma cells by inducing cell cycle arrest, apoptosis, and, in part, by promoting melanocytic differentiation through inactivation of ERK signaling. Our present study indicates that trabectedin is a promising differentiation‐inducing agent for clear cell sarcoma.

Bone Tissue Engineering Using Novel Interconnected Porous Hydroxyapatite Ceramics Combined with Marrow Mesenchymal Cells: Quantitative and Three-Dimensional Image Analysis

We developed fully opened interconnected porous calcium hydroxyapatite ceramics having two different pore sizes. One has pores with an average size of 150 μm in diameter, an average 40-μm interconnecting pore diameter, and 75% porosity (HA150). The other has pores with an average size of 300 μm in diameter, an average 60–100-μm interconnecting pore diameter, and 75% porosity (HA300). Because of its smaller pore diameter, HA150 has greater mechanical strength than that of HA300. These ceramics were combined with rat marrow mesenchymal cells and cultured for 2 weeks in the presence of dexamethasone. The cultured ceramics were then implanted into subcutaneous sites in syngeneic rats and harvested 2–8 weeks after implantation. All the implants showed bone formation inside the pore areas as evidenced by decalcified histological sections and microcomputed tomography images, which enabled three-dimensional analysis of the newly formed bone and calculation of the bone volume in the implants. The bone volume increased over time. At 8 weeks after implantation, extensive bone volume was detected not only in the surface pore areas but also in the center pore areas of the implants. A high degree of alkaline phosphatase activity with a peak at 2 weeks and a high level of osteocalcin with a gradual increase over time were detected in the implants. The levels of these biochemical parameters were higher in HA150 than in HA300. The results indicate that a combination of HA150 and mesenchymal cells could be used as an excellent bone graft substitute because of its mechanical properties and capability of inducing bone formation.

Therapeutic potential of TAS-115 via c-MET and PDGFRα signal inhibition for synovial sarcoma

Background

The prognosis of synovial sarcoma (SS), an aggressive soft tissue sarcoma, remains poor. We previously reported that c-MET or platelet-derived growth factor receptor α (PDGFRα) signalling pathway is related to SS progression based upon the findings of phospho-receptor tyrosine kinase (RTK) arrays. TAS-115 is a novel c-MET/ vascular endothelial growth factor receptor-targeting tyrosine kinase inhibitor that has been shown to inhibit multiple RTKs. Here we aimed to investigate the therapeutic potential of TAS-115 against SS.

Methods

We first evaluated which signalling pathway was relevant to the viability of three human SS cell lines: Yamato-SS, SYO-1 and HS-SY-II. Next, we assessed the anticancer activity and mechanism of action of TAS-115 in these SS cell lines. Finally, we compared the ability of TAS-115 to inhibit c-MET and PDGFRα phosphorylation with that of pazopanib.

Results

We classified the SS cell lines as c-MET-dependent or PDGFRα-dependent based upon the differences in the signalling pathway relevant for growth and/or survival. We also found that c-MET and PDGFRα were the primary activators of both phosphatidylinositol 3-kinase/AKT and mitogen-activated protein kinase pathways in c-MET-dependent and PDGFRα-dependent SS cells, respectively. TAS-115 treatment blocked the phosphorylation of PDGFRα as well as that of c-MET and their downstream effectors, leading to marked growth inhibition in both types of SS cell lines in in vitro and in vivo studies. Furthermore, PDGFRα phosphorylation, on at least four representative autophosphorylation sites, was impeded by TAS-115 equivalently to pazopanib.

Conclusions

These experimental results have demonstrated the significance of c-MET and PDGFRα signalling for growth and/or survival of SS tumours. TAS-115 monotherapy may benefit SS patients whose tumours are dependent upon either c-MET or PDGFRα signalling by functioning as a multiple tyrosine kinase inhibitor to suppress c-MET as well as PDGFRα pathways.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3324-3) contains supplementary material, which is available to authorized users.

Radiofrequency ablation of osteoid osteoma using a three-dimensional navigation system

OBJECTIVE

This study aimed to report the clinical outcomes for patients with osteoid osteoma (OO) treated by radiofrequency ablation (RFA) using a three-dimensional (3D) navigation system.

METHODS

We performed RFA using a 3D navigation system on 32 patients with clinically and radiologically diagnosed OO. This study included 25 males and 7 females with a median age of 20 years (range, 10-39 years). The median duration of follow-up was 18 months (range, 1-65 months). We investigated technical specifications, tumor localization, technical success, clinical success, biopsy success, complications, incomplete treatment, and recurrences.

RESULTS

Eighteen tumors were located in the femur, seven in the tibia, two in the humerus, and one each in the fibula, scapula, patella, lumbar vertebra, and acetabula. All procedures were technically successful, and pain relief was achieved in all patients. However, local recurrence developed in one patient, needing additional RFA. The clinical success rate was 96.8%. Biopsy showed OO in 12 patients (37%). Complications occurred in three patients (9%), two cases of fractures and one of osteomyelitis.

CONCLUSIONS

A 3D navigation provides real-time imaging and enables us to set the RFA needle in the correct position, particularly in case of OO-aroused complex anatomical structures. Our initial results indicated that radiofrequency ablation using a 3D navigation system is feasible and safe for patients with OO.

Phase I/II Multi-Institutional Study of Percutaneous Radiofrequency Ablation for Painful Osteoid Osteoma (JIVROSG-0704)

PURPOSE

This multicenter prospective study was conducted to evaluate the safety and efficacy of percutaneous radiofrequency ablation (RFA) for painful osteoid osteoma (OO).

MATERIALS AND METHODS

Patients with OO (femur: n = 17, tibia: n = 2, humerus: n = 1, rib: n = 1) were enrolled and treated with RFA. In phase I, nine patients were evaluated for safety. In phase II, 12 patients were accrued, and an intent-to-treat analysis was performed on all patients. The primary endpoint was to evaluate the treatment safety. The secondary endpoint was to evaluate the efficacy for pain relief by the visual analogue scale (VAS) at 4 weeks after RFA. Treatment efficacy was classified as significantly effective (SE) when VAS score decreased by ≥5 or score was <2, moderately effective when VAS score decreased by <5-≥2 and score was ≥2, and not effective (NE) when VAS score decreased by <2 or score was increased. Cases where the need for analgesics increased after treatment were also NE.

RESULTS

RFA procedures were completed in all patients. Minor adverse effects (AEs) were observed as 4.8-14.3 % in 12 patients, and no major AEs were observed. Mean VAS score was 7.1 before treatment, 1.6 at 1 week, 0.3 at 4 weeks, and 0.2 at 3 months. All procedures were classified as SE. Pain recurrence was not noted in any patient during follow-up (mean: 15.1 months).

CONCLUSION

RFA is a safe, highly effective, and fast-acting treatment for painful extraspinal OO. Future studies with a greater number of patients are needed.

Preparation of Scaffold-Free Tissue-Engineered Constructs Derived from Human Synovial Mesenchymal Stem Cells Under Low Oxygen Tension Enhances Their Chondrogenic Differentiation Capacity

Low oxygen tension (LOT) has been reported to promote chondrogenic differentiation and prevent cellular senescence of stem cells. Therefore, the introduction of LOT conditions into conventional tissue engineering processes could further improve the potential of the constructs generated for cartilage repair. The purpose of this study was to elucidate the feasibility of LOT preparation on the chondrogenic differentiation of a scaffold-free tissue-engineered construct (TEC) derived from synovial mesenchymal stem cells (MSCs), construct whose feasibility for cartilage repair has been demonstrated in previous preclinical and clinical studies. Culture of MSCs under LOT conditions prevented cellular senescence and promoted the proliferative capacity of human synovial MSCs. In addition, TEC prepared from human synovial MSCs under LOT conditions (5% O2; LOT-TEC) showed superior in vitro chondrogenic differentiation capacity compared to that prepared under the usual 20% O2 (normal oxygen tension [NOT]; NOT-TEC), with elevated glycosaminoglycan production and elevated levels of chondrogenic marker gene expression. Notably, LOT-TEC differentiated into a hyaline-like cartilaginous tissue of approximately 1 cm in diameter without the detectable presence of fibrous tissue, while conventional NOT-TEC differentiated into a mixture of hyaline-like and fibrocartilaginous tissues. This is the first demonstration of in vitro development of a hyaline-like cartilaginous tissue of an implantable size to chondral lesion that was derived from human MSCs without the use of an exogenous scaffold. The manipulation of oxygen tension is a safe procedure with low cost and, thus, may be a clinically relevant option to improve the quality of TEC-mediated cartilage repair.

Trabectedin is a promising antitumour agent for synovial sarcoma

Synovial sarcoma (SS) is an aggressive soft tissue tumour with poor prognosis. Using five human SS cell lines, we examined the cytotoxic effects of trabectedin (ET-743; Yondelis(®)), a novel marine natural product, which was approved in Europe for the treatment of soft tissue sarcomas (STS). The significant growth inhibitory effects were observed in all SS cell lines below nanomolar concentration of trabectedin. Furthermore, trabectedin significantly suppressed the tumour growth in xenograft models. Flow cytometer analysis in vitro and immunohistochemical analysis in vivo revealed its effect of cell cycle inhibition and apoptosis induction. We also examined the expression of ERCC1, 5 and BRCA1 in SS cell lines and clinical samples, and majority of them showed highly trabectedin-sensitive pattern as previously reported in other cancers. Our preclinical data indicated that trabectedin could be a promising therapeutic option for patients with SS.

Repairing Osteochondral Defects of Critical Size Using Multiple Costal Grafts: An Experimental Study

OBJECTIVE

To investigate the feasibility of repairing osteochondral defects of critical size by performing mosaicplasty using multiple sliced costal cartilage grafts, which enables repair of extensively injured knees using grafts from a single rib.

DESIGN

Critical osteochondral defects were prepared on the femoral groove of skeletally mature Japanese white rabbits. Costal cartilage grafts from a single rib were harvested and sliced into multiple segments (approximately 3-5 mm in length). The defects were left untreated or repaired by performing mosaicplasty using costal cartilage grafts (with or without a longitudinal cut along the middle). At 4 and 12 weeks after transplantation, International Cartilage Repair Society macroscopic and histological grading was performed.

RESULTS

The macroscopic score and visual histological score were significantly higher in the repaired groups than in the untreated group at 4 and 12 weeks after surgery. Histological continuous integration between grafted costal cartilage and host bone was observed in both repaired groups.

CONCLUSIONS

The findings suggest that costal cartilage might be a useful alternative source for chondral grafting. We were able to repair large osteochondral defects by performing mosaicplasty using multiple sliced costal cartilage grafts from a single rib.

A giant periosteal chondroma of the distal femur successfully reconstructed with synthetic bone grafts and a bioresorbable plate: a case report

Periosteal chondromas are rare benign cartilaginous tumors that arise adjacent to the cortex beneath the periosteum. These lesions are usually slow-growing and rarely exceed 3 cm in the greatest dimension. Here, we describe a 17-year-old boy who had a giant periosteal chondroma of the right distal femur, which was treated with intralesional resection and intensive curettage. In addition, we report a novel application of a bioresorbable plate in the management of the large bone defect after resection of a benign bone tumor.

Combined targeting of mTOR and c-MET signaling pathways for effective management of epithelioid sarcoma

Background

Epithelioid sarcoma (EpS) is a high-grade malignant soft-tissue sarcoma characterized by local recurrences and distant metastases. Effective treatments for EpS have not been established and thus novel therapeutic approaches against EpS are urgently required. mTOR inhibitors exert antitumor effects on several malignancies but AKT reactivation by mTOR inhibition attenuates the antitumor effects of mTOR inhibitors. This reactivation is receptor tyrosine kinase (RTK)-dependent due to a release of negative feedback inhibition. We found that c-MET was the most highly activated RTK in two human EpS cell lines, Asra-EPS and VAESBJ. Here we investigated the functional and therapeutic relevance of mTOR and/or c-MET signaling pathways in EpS both in vitro and in vivo.

Methods

We first examined the effects of an mTOR inhibitor, RAD001 (everolimus), on cell proliferation, cell cycle, AKT/mTOR signaling, and xenograft tumor growth in EpS cell lines. Next, we determined whether RAD001-induced AKT reactivation was blocked by silencing of c-MET or treatment with a selective c-MET inhibitor, INC280. Finally, we evaluated the antitumor effects of RAD001 combined with INC280 on EpS cell lines compared with either single agent or control in vitro and in vivo.

Results

Constitutive AKT phosphorylation was observed in Asra-EPS and VAESBJ cells. RAD001 suppressed EpS cell growth by inducing cell cycle arrest but enhanced AKT phosphorylation, which resulted in intrinsic resistance to mTOR inhibitors. In both EpS cell lines, RAD001-induced AKT phosphorylation was dependent on c-MET signaling. INC280 inhibited phosphorylation of c-MET and its downstream molecules, and decreased RAD001-induced phosphorylation of both AKT and ERK in EpS. Compared with a single agent or control, the combination of RAD001 and INC280 exerted superior antitumor effects on the growth of EpS cell lines in vitro and in vivo.

Conclusions

Targeting of mTOR and c-MET signaling pathways significantly abrogates the growth of EpS in preclinical models and may be a promising therapeutic approach for patients with EpS.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-185) contains supplementary material, which is available to authorized users.

Neoadjuvant and adjuvant chemotherapy with high-dose ifosfamide, doxorubicin, cisplatin and high-dose methotrexate in non-metastatic osteosarcoma of the extremities: a phase II trial in Japan

From 1997 to 2003, 40 patients (all <40 years of age) with non-metastatic osteosarcoma of the extremities were treated with OOS-D and definitive surgery. Two cycles of doxorubicin 90 mg/m(2) plus cisplatin 120 mg/m(2) and ifosfamide 15 g/m(2) were given as neoadjuvant chemotherapy, and two cycles of doxorubicin/cisplatin and ifosfamide, and two cycles of high-dose methotrexate (10-12 g/m(2)) were given post-operatively. All patients underwent limb salvage surgeries, and 66% showed good response to neoadjuvant chemotherapy. With a median follow-up period of 117 months, 31 of the evaluable 40 patients were continuously disease-free, 7 were currently alive with no evidence of disease, and 2 died of disease. There was no local recurrence. The 5-year event-free and overall survival rates were 83 and 98%, respectively. The 10-year event-free and overall survival rates were 80 and 95%, respectively. The major form of toxicity was haematological one.

A novel angiomatoid epithelioid sarcoma cell line, Asra-EPS, forming tumors with large cysts containing hemorrhagic fluid in vivo

BACKGROUND

Whereas we can use several human epithelioid sarcoma (ES) cell lines for basic and preclinical research, an angiomatoid ES cell line has not been reported to date. We have treated a case of an angiomatoid ES developing in the right upper extremity of a 67-year-old man.

METHODS

An angiomatoid ES cell line, Asra-EPS was newly established and characterized for its morphology, growth rate and chromosomal analysis. Tumorigenicity of Asra-EPS cells was also analyzed in athymic nude mice.

RESULTS

Asra-EPS cells were round, polygonal or spindle-shaped with an abundant cytoplasm and have been maintained continuously in vitro for over 150 passages during more than 15 months. These cells secreted cancer antigen 125 (CA 125), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) into the culture medium. Asra-EPS cells were tumorigenic when implanted in nude mice with tumors reaching a volume of 1000 mm3 at around 50 days. Histological features of tumors formed in mice were essentially the same as those of the original tumor, exhibiting a multinodular proliferation of eosinophilic epithelioid and spindle-shaped cells with prominent areas of hemorrhage and blood-filled cystic spaces strikingly corresponding to the potential of hemorrhagic cyst formation in the original tumor. They showed immunopositive staining for cytokeratins (AE1/AE3 and CAM5.2), epithelial membrane antigen (EMA), vimentin, CD31, CD34 and CA 125, but negative for integrase interactor 1 (INI-1) and factor VIII-related antigen.

CONCLUSIONS

The established cell line represents a biologically relevant new tool to investigate the molecular pathology of human angiomatoid ES and to evaluate the efficacy of novel therapeutics both in vitro and in vivo.

Bone tissue engineering with bone marrow-derived stromal cells integrated with concentrated growth factor in Rattus norvegicus calvaria defect model

Concentrated growth factor (CGF) is an autologous leukocyte-rich and platelet-rich fibrin (L-PRF) biomaterial termed "second-generation platelet concentrate". CGF contains autologous osteoinductive platelet growth factors and an osteoconductive fibrin matrix. The purpose of this study was to assess the ability of CGF combined with bone marrow stromal cells (BMSCs) to heal critical-size rat calvaria defects in vivo and to modulate the proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro. In the in-vivo study, the CGF group regenerated bone better than the control group, and combined therapy with CGF and BMSCs almost completely repaired critical-size bone defects within 12 weeks after surgery. In the in-vitro study, the CGF extract, at concentrations between 1 and 10%, promoted proliferation, osteogenic maturation, and mineralization of hTERT-E6/E7 human MSCs in a dose-dependent manner but had an inhibitory effect at higher concentrations. In conclusion, a CGF extract promoted the proliferation, osteogenic maturation, and mineralization of mesenchymal stem cells in vitro, and combination therapy with CGF and BMSCs resulted in excellent healing of critical-size bone defects in vivo.

Bone-derived IGF mediates crosstalk between bone and breast cancer cells in bony metastases

The continuous release of bone-stored growth factors after bone resorption promotes the colonization of circulating cancer cells. However, the precise role of each of the various growth factors remains unclear. In this study, we investigated the role of bone-derived insulin-like growth factor (IGF) in the development of bone metastases in an animal model of breast cancer. We found that local stimulation of calvarial bone resorption before cell inoculation stimulated subsequent bone metastases to that site in vivo, although inhibition of bone resorption inhibited bone metastases. Anchorage-independent growth of cancer cells was stimulated by the culture supernatants from resorbed bones, which contained elevated levels of IGF-I. This stimulation was blocked by IGF type I receptor (IGF-IR) neutralizing antibody, but not antibody targeting other bone-stored growth factors including TGF-β, fibroblast growth factors, and platelet-derived growth factors. Although recombinant human IGF-I caused IGF-IR tyrosine autophosphorylation, followed by activation of Akt and NF-κB in cancer cells, dominant-negative inhibition of IGF-IR, Akt, or NF-κB significantly reduced bone metastases with increased apoptosis and decreased mitosis in metastatic cells. Together, our findings suggest that bone-derived IGF-I bridges the crosstalk between bone and metastasized cancer cells via activation of the IGF-IR/Akt/NF-κB pathway. Disruption of this pathway therefore may represent a promising therapeutic intervention for bone metastasis.

Biomechanical evaluation of porous bioactive ceramics after implantation: micro CT-based three-dimensional finite element analysis

Hydroxyapatite ceramics have been widely investigated for bone regeneration due to their high biocompatibility. However, few studies focus on their mechanical characteristics after implantation. In this study, the finite element (FE) method was used to evaluate the mechanical properties of a fully interconnected porous hydroxyapatite (IPHA) over time of implantation. Based on the micro-CT images obtained from the experiments dealing with IPHA implanted into rabbit femoral condyles, three-dimensional FE models of IPHA (1, 5, 12, 24, and 48 weeks after implantation) were developed. FE analysis indicated that the elastic modulus gradually increased from 1 week and reached the peak value at 24 weeks, and then it kept at high level until 48 weeks postoperatively. In addition, as a local biomechanical response, strain energy density became to distribute evenly over time after the implantation. Results confirmed that the mechanical properties of IPHA are strongly correlated to bone ingrowth. The efficiency of the proposed numerical approach was validated in combination with experimental studies, and the feasibility of applying this approach to study such implanted porous bioceramics was proved.

Biased usage of T cell receptor β-chain variable region genes of Wilms' tumor gene (WT1)-specific CD8+ T cells in patients with solid tumors and healthy donors

Wilms' tumor gene 1 (WT1) protein is a promising tumor-associated antigen. In patients with WT1-expressing malignancies, WT1-specific CTLs are spontaneously induced as a result of an immune response to the WT1 protein. In the present study, we performed single cell-level comparative analysis of T cell receptor β-chain variable region (TCR-BV) gene families of a total of 750 spontaneously induced WT1(126) peptide (amino acids 126-134, WT1(126))-specific CTLs in both HLA-A*0201(+) patients with solid tumors and healthy donors (HDs). This is the first report of direct usage analysis of 24 kinds of TCR-BV gene families of WT1(126)-specific CTLs at the single cell level. Usage analysis with single-cell RT-PCR of TCR-BV gene families of individual FACS-sorted WT1(126) tetramer(+) CD8(+) T cells showed, for the first time, that: (i) BVs 3, 6, 7, 20, 27, and 28 were commonly biased in patients and HDs; (ii) BVs 2, 11, and 15 were biased only in patients; and (iii) BVs 4, 5, 9, and 19 were biased only in HDs. However, statistical analysis of similarity of individual usage frequencies of 24 kinds of TCR-BV gene families between patients and HDs indicated that the usage frequencies of TCR-BV gene families in patients reflected those in HDs. These results should provide us with a novel insight for a better understanding of WT1-specific immune responses.

TUMOR NECROSIS FACTOR-α CONVERTING ENZYME EXPRESSION IN THE JOINTS OF RHEUMATOID ARTHRITIS PATIENTS

The purpose of this study is to investigate the expression of tumor necrosis factor-α converting enzyme (TACE) in the synovium and subchondral bone region of patients with rheumatoid arthritis (RA) and to determine the contribution of the enzyme to the pathogenesis of RA.

Joint tissues were obtained during total knee arthroplasty from patients with RA and osteoarthritis (OA). The expression of TACE and TNF-α mRNA was detected by in situ hybridization. Characterization of TACE expressing cells was performed by immunohistochemistry using serial sections.

We found that TACE mRNA was expressed in both synovium and subchondral bone region and co-localized with TNF-α mRNA in RA. On the other hand, TACE mRNA expression was scarcely detectable in OA samples. TACE was expressed in mononuclear cells, such as CD3 and CD14 positive cells in RA samples.

In conclusion, the expression of TACE is up-regulated in the rheumatoid synovium and subchondral bone region, and the results in this study demonstrate that TACE may be involved and play a role in the pathogenesis of RA.

Nkx3.2-induced suppression of Runx2 is a crucial mediator of hypoxia-dependent maintenance of chondrocyte phenotypes

Hypoxia is a key factor in the maintenance of chondrocyte identity. However, crucial chondrogenic transcription factors in the Sox families are not activated in this phenomenon, indicating that other pathways are involved. Nkx3.2 is a well-known chondrogenic transcription factor induced by Sonic hedgehog (Shh); it suppresses a key osteogenic transcriptional factor, Runt-related transcription factor 2 (Runx2), to maintain the chondrogenic phenotype in mesenchymal lineages. The purpose of this study was to examine the function of Nkx3.2 in hypoxia-dependent maintenance of chondrocyte identity. C3H10T1/2 pluripotent mesenchymal cells were cultured with rh-BMP2 (300 ng/ml) to induce chondrogenesis under normoxic (20% O(2)) or hypoxic (5% O(2)) conditions. Immunohistological detection of Nkx3.2 in a micromass cell culture system revealed that hypoxia promoted expression of the Nkx3.2 protein. Real-time RT-PCR analysis revealed that hypoxia promoted Nkx3.2 mRNA expression and suppressed Runx2 mRNA expression; however, Sox9 mRNA expression was not altered by oxygen conditions, as previously described. Over-expression of exogenous Nkx3.2 promoted glycosaminoglycan (GAG) production and inhibited Runx2 mRNA expression and, based on a dual luciferase assay, Runx2 promoter activity. Interestingly, downregulation of Nkx3.2 using RNAi abolished hypoxia-dependent GAG production and restored Runx2 mRNA expression and promoter activity. These results demonstrated that Nkx3.2-dependent suppression of Runx2 was a crucial factor in hypoxia-dependent maintenance of chondrocyte identity.

Activation of nuclear factor-kappa B by linear ubiquitin chain assembly complex contributes to lung metastasis of osteosarcoma cells

NF-κB is involved in the metastasis of malignant cells. We have shown that NF-κB activation is involved in the pulmonary metastasis of LM8 cells, a highly metastatic subclone of Dunn murine osteosarcoma cells. Recently, it was determined that a newly identified type of polyubiquitin chain, a linear polyubiquitin chain, which is specifically generated by the linear ubiquitin chain assembly complex (LUBAC), plays a critical role in NF-κB activation. Here, we have evaluated the roles of LUBAC-mediated NF-κB activation in the development of lung metastasis of osteosarcoma cells. All three components of LUBAC (HOIL-1L, HOIP and SHARPIN) were highly expressed in LM8 cells compared to Dunn cells. Attenuation of LUBAC expression by stable knockdown of HOIL-1L in LM8 cells significantly suppressed NF-κB activity, invasiveness in vitro and lung metastasis. Induction of intracellular adhesion molecule-1 (ICAM-1) expression by LUBAC is involved in cell retention in the lungs after an intravenous inoculation of tumor cells. Moreover, we found that knockdown of LUBAC decreased not only the number but also the size of the metastatic nodules of LM8 cells in the lungs. These results indicate that LUBAC-mediated NF-κB activation plays crucial roles in several steps involved in metastasis, including extravasation and growth of osteosarcoma cells in the lung, and that suppression of LUBAC-mediated linear polyubiquitination activity may be a new approach to treat this life-threatening disease of young adolescents.

Feasibility and limitations of the round robin test for assessment of in vitro chondrogenesis evaluation protocol in a tissue-engineered medical product

Tissue-engineered medical products (TEMPs) should be evaluated before implantation. Therefore, it is indispensable to establish evaluation protocols in regenerative medicine. Whether or not such evaluation protocols are reasonable is generally verified through a 'round robin' test. However, the round robin test for TEMPs intrinsically includes a deficiency, because 'identical' specimens can not be prepared for TEMPs. The aim of the study was to assess the feasibility and limitations of the round robin test for TEMPs by using a prepared evaluation protocol. We adopted tissue-engineered cartilage constructs as delivered specimens and a protocol of measuring sGAG content as an evaluation protocol proposed to ISO TC150/SC7, which is an invasive, but usually applied, method, although non-invasive methods are keenly required in evaluating TEMPs. The results showed that: (a) the coefficient of variation (CV) of the measured sGAG contents in intralaboratory tests was ~5% at most; (b) the CV of sGAG content in the scheme where each participating laboratory measured different constructs was comparable with that in the scheme where each participating laboratory measured one half of a construct along with the organizing laboratory; (c) the CV caused by factors other than the specimen was ~15%, comparable to that in reproducible experiments in biomedical fields. Based on these results, the study concludes that a round robin test for a TEMP could be valuable, under the condition that the delivered TEMPs are sufficiently reproducible so that the CV of the measured values is < 5% in the organizing laboratory.

Radio-sensitization of the murine osteosarcoma cell line LM8 with parthenolide, a natural inhibitor of NF-κB

Nuclear factor (NF)-κB has been shown to be associated with cancer resistance to radiotherapy (RT), and is constitutively active in the murine osteosarcoma cell line, LM8. Parthenolide has been reported to show antitumor activity through inhibition of the NF-κB pathway. In this study, we investigated the radio-sensitizing activity of parthenolide. We established Luc-LM8, a stable transfectant reporter construct of NF-κB transcriptional activity into LM8. Luc-LM8 maintained the malignancy observed with LM8. In vitro, Luc-LM8 cells were cultured with or without parthenolide treatment, irradiated, and subjected to cell viability and apoptosis assays. In vivo, to investigate whether parthenolide enhances radio-sensitivity of tumors, a tumor growth assay was conducted. Parthenolide enhanced the growth inhibitory effect of RT and induced the apoptosis of Luc-LM8 cells with RT in vitro. The in vivo tumor growth was significantly suppressed in the mice treated with parthenolide and RT. The present study suggests that parthenolide sensitizes Luc-LM8 cells to irradiation. Thus, parthenolide is a potential candidate for use as a potent radio-sensitizing drug for use in cancer RT.

Influence of knee positions on T2, T*2, and dGEMRIC mapping in porcine knee cartilage

We examined the influence of flexed knee positions on cartilage MR assessments. Sagittal T(2), T*(2), and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) maps of the femoral cartilage were obtained in eight 6-month-old porcine femorotibial joints in the extended knee position (position A: flexion 0 degrees and femoral shaft in parallel with the amplitude of static field), flexed knee position (position B: flexion 40 degrees and femoral shaft oriented at 40 degrees to the amplitude of static field), and oblique-placed knee-extended position (position C: flexion 0 degrees and femoral shaft oriented at 40 degrees to the amplitude of static field). Comparison of the MR parameters between positions A and C showed isolated influence of the magic-angle effect, and comparison between positions A and B showed effects of knee flexion. Proteoglycan and hydroxyproline content in cartilage specimen at each region of interest had no significant correlation with T(2), T*(2), and dGEMRIC values. At the central zone, located on a weight-bearing area and parallel to the amplitude of static field, T(2)/T*(2)/dGEMRIC values increased by 6.8/11/0.8% at position C and by 24/44/31% at position B compared with position A. There was a significant increase in T(2) and T*(2) values at position B compared with those at position A. The substantial changes in T(2), T*(2), and dGEMRIC were shown in response to knee flexion, presumably due to the compounding influence of the magic-angle effect and change in the intra-articular biomechanical condition.

Eleven cases of cardiac metastases from soft-tissue sarcomas

OBJECTIVE

Cardiac metastasis is a highly life-threatening condition because it leads to cardiac failure. However, it is difficult to diagnose because its precise clinical features are unknown. Here, we report 11 cases of cardiac metastasis from soft-tissue sarcoma, and discuss its diagnosis and treatment.

METHODS

Of 641 patients with soft-tissue sarcoma treated in our institute between 1996 and 2009, we retrospectively reviewed the medical records of 11 patients whose cardiac metastases were diagnosed while they were alive.

RESULTS

The most common primary tumor was leiomyosarcoma (n= 5), followed by clear cell sarcoma (n= 2). In all cases, metastases to other organs, including lungs (n= 10), soft tissues (n= 5) and bones (n= 4) were found along with cardiac metastases. Cardiac metastasis was diagnosed by echocardiography in six cases and by computed tomography in four cases. In four patients, cardiac metastasis was not detected by chest computed tomography as follow-up to lung metastases and echocardiography was required to make the diagnosis. Although five patients complained of exertional dyspnea, four were asymptomatic. Seven cases were treated with radiotherapy. No patient had surgery for their cardiac metastasis. The median survival of patients who received radiation therapy was 10.5 months; that of those who did not was 3.5 months.

CONCLUSIONS

Cardiac metastasis is often asymptomatic. Echocardiography is better than computed tomography for diagnosing cardiac metastasis, and should be considered in all patients presenting with soft-tissue metastases. Owing to the highly life-threatening nature of cardiac metastases and the possibility of soft-tissue dissemination, treatment with radiation therapy is recommended immediately on diagnosis.

Loading and knee alignment have significant influence on cartilage MRI T2 in porcine knee joints

OBJECTIVE

Physiological magnetic resonance imaging (MRI) under loading or knee malalignment conditions has not been thoroughly investigated. We assessed the influence of static loading and knee alignment on T2 (transverse relaxation time) mapping of the knee femoral cartilage of porcine knee joints using a non-metallic pressure device.

METHODS

Ten porcine knee joints were harvested en bloc with intact capsules and surrounding muscles and imaged using a custom-made pressure device and 3.0-T MRI system. Sagittal T2 maps were obtained (1) at knee neutral alignment without external loading (no loading), (2) under mechanical compression of 140 N (neutral loading), and (3) under the same loading conditions as in (2) with the knee at 10 degrees varus alignment (varus loading). T2 values of deep, intermediate, and superficial zones of the medial and lateral femoral cartilages at the weight-bearing area were compared among these conditions using custom-made software. Cartilage contact pressure between the femoral and tibial cartilages, measured by a pressure-sensitive film, was correlated with cartilage T2 measurements.

RESULTS

In the medial cartilage, mean T2 values of the deep, intermediate, and superficial zones decreased by 1.4%, 13.0%, and 6.0% under neutral loading. They further decreased by 4.3%, 19.3%, and 17.2% under varus loading compared to no loading. In the lateral cartilage, these mean T2 values decreased by 3.9%, 7.7%, and 4.2% under neutral loading, but increased by 1.6%, 9.6%, and 7.2% under varus loading. There was a significant decrease in T2 values in the intermediate zone of the medial cartilage under both neutral and varus loading, and in the superficial zone of the medial cartilage under varus loading (P<0.05). Total contact pressure values under neutral loading and varus loading conditions significantly correlated with T2 values in the superficial and intermediate zones of the medial cartilages.

CONCLUSIONS

The response of T2 to change in static loading or alignment varied between the medial and lateral cartilages, and among the deep, intermediate, and superficial zones. These T2 changes were significantly related to the contact pressure measurements. Our results indicate that T2 mapping under loading allows non-invasive, biomechanical assessment of site-specific stress distribution in the cartilage.

Novel fully interconnected porous hydroxyapatite ceramic in surgical treatment of benign bone tumor

BACKGROUND

Large bone defects remaining after curettage of benign bone tumors should be filled with a substitute to restore mechanical strength. In 2000, we developed a fully interconnected porous calcium hydroxyapatite ceramic (IPCHA, NEOBONE) and have utilized it as a bone substitute. IP-CHA has a finely organized, three-dimensional interconnecting pore structure. The large interconnecting channels (average diameter 40 microm) permit easy penetration of tissue into the deep pores, so IP-CHA can itself induce local bone repair processes. The purpose of this study was to evaluate the clinical outcomes with the use of IP-CHA as bone substitute after curettage of benign bone tumors.

METHODS

We reviewed the results of 71 patients with benign bone tumors sequentially treated by curettage followed by implantation of IP-CHA between 2000 and 2006. There were 29 women and 42 men, with a mean age of 28 years. Assessment was based on radiography at each time point during the follow-up. Radiographic findings were classified into five stages: stage 0, no change; stage 1, slight bone formation; stage 2, moderate bone formation; stage 3, consolidation; stage 4, absorption.

RESULTS

In 70 of 74 operated lesions, radiographs showed that implanted IP-CHA proceeded to stage 2 or more within an average of 8 months after the surgery. In addition, 17 lesions proceeded to stage 4 within 35 months after surgery, on average. However, there were 10 local recurrences, which is similar to the recurrence rate for such tumors treated with or without implantation of CHAs and reflects the biological nature of each tumor.

CONCLUSIONS

In this study, we utilized IP-CHA as a bone substitute after curettage of benign bone tumors and demonstrated its usefulness in the clinical situation. IP-CHA comparatively exhibited excellent bone formation at an early stage although the problem of recurrence of the tumor remained. We conclude that IP-CHA is a useful bone substitute for the treatment of benign bone tumors.

A clear correlation between WT1-specific Th response and clinical response in WT1 CTL epitope vaccination

Clinical studies of WT1-targeted cancer vaccine are being performed. However, WT1-specific Th response in cancer patients remains unclear. Using quantitative real-time RT-PCR, we investigated IFN-gamma and IL-10 mRNA expression from Th cells by stimulation with helper peptide WT1(332). Seventeen patients, of whom 10 had achieved stable disease and the remaining 7 had progressive disease, were weekly vaccinated with WT1 CTL epitope (modified WT1(235)) and examined for WT1(332)-specific Th response. A clear correlation between WT1(332)-specific Th response and clinical response was observed at 4 weeks post-vaccination. In patients who responded, a clear inverse correlation between IL-10-type and IFN-gamma-type WT1(332)-specific Th response was detected at pre- and 4 weeks post-vaccination, and the shift of the Th response from IL-10-type dominancy at early phase to IFN-gamma-type dominancy at late phase was observed. From this study we concluded that occurrence of WT1(332)-specific Th response could predict good clinical response of WT1 CTL epitope vaccination.

Specificity of fusion genes in adipocytic tumors

BACKGROUND

In subsets of adipocytic tumors, specific chromosomal translocations lead to the generation of fusion genes. The high mobility group A2 (HMGA2)-lipoma preferred partner (LPP) and the reciprocal LPP-HMGA2 represent such fusion genes in lipoma, while the human translocation liposarcoma (TLS)-CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP) and the Ewing sarcoma (EWS)-CHOP in liposarcoma. However, the specificity of these fusion genes has not been established in a variety of adipocytic tumors.

PATIENTS AND METHODS

One hundred and seventy-two cases of adipocytic tumors, comprising 98 cases of lipoma and 74 cases of liposarcoma, were analyzed for the possible expression of HMGA2-LPP, LPP-HMGA2, TLS-CHOP and EWS-CHOP fusion genes, using a reverse-transcription polymerase chain reaction method.

RESULTS

In lipoma, twenty-two cases (22.4%) were associated with either HMGA2-LPP or LPP-HMGA2, while neither TLS-CHOP nor EWS-CHOP transcript was detectable. On the contrary, in liposarcoma, neither HMGA2-LPP nor LPP-HMGA2 transcript was detectable, although twenty-five cases (33.8%) were related to either TLS-CHOP or EWS-CHOP.

CONCLUSION

HMGA2-LPP and LPP-HMGA2 were specific to lipoma, and TLS-CHOP and EWS-CHOP were specific to liposarcoma.

A comparative assessment of synthetic ceramic bone substitutes with different composition and microstructure in rabbit femoral condyle model

Various bone substitutes with improved biocompatibility have been developed. Because these products vary in composition and microstructure, it is difficult to understand each feature and make an appropriate selection. Three recently developed highly porous ceramic bone substitutes were evaluated, including two made of hydroxyapatite with different structures (Apaceram-AX: 85%-porosity with micropores, NEOBONE: 75%-porosity without micropores) and one composed of beta-tricalcium phosphate (OSferion: 75%-porosity with micropores) in a rabbit model. Apaceram-AX showed gradual degradation, while NEOBONE remaining intact. OSferion was almost completely degraded at 24 weeks. Numerous osteoclasts were detected in materials with micropores, whether Apaceram-AX or OSferion, but not in NEOBONE. These differences of biodegradability seemed to be related to the presence of micropores. The compressive strength of OSferion increased for several weeks and decreased at a level of cancellous bone. The strength of NEOBONE gradually increased and remained at the highest level among three. The strength of Apaceram-AX increased two to three times that of cancellous bone. Surprisingly, the strength of all materials declined during the initial 1 week, suggesting that great care should be taken in the early period after implantation. These findings may help surgeons to select an appropriate porous substitute based on understanding of their features.