Akihito Nagano

EWS-Fli1 Up-Regulates Expression of the Aurora A and Aurora B Kinases

EWS-Fli1, a fusion gene resulting from the chromosomal translocation t(11;22, q24;q12), encodes a transcriptional activator, promotes cellular transformation, and is often found in Ewing sarcoma and primitive neuroectodermal tumor. The Aurora A and Aurora B kinases belong to a highly conserved family of serine/threonine protein kinases, are tightly regulated during the cell cycle, and are overexpressed in many carcinomas. Because the relationship between the Aurora A and/or Aurora B genes and the EWS-Fli1 fusion gene is unknown, we investigated the regulatory mechanism(s) by which Aurora kinases are controlled. Knockdown of EWS-Fli1 by small interfering RNA reduced mRNA levels not only of EWS-Fli1 but also of Aurora A and Aurora B. Luciferase assay using Aurora A and Aurora B promoters showed up-regulated activities compared with those of an empty vector. Experiments with deletion and point mutants showed positive regulatory Ets-binding sites located −84 and −71 bp upstream of the transcription initiation sites in Aurora A and Aurora B, respectively. Moreover, chromatin immunoprecipitation assay revealed that EWS-Fli1 gene products interact with both the Aurora A and Aurora B promoters. These results strongly suggest that the mitotic kinases Aurora A and Aurora B are regulated by EWS-Fli1 fusion protein in Ewing sarcoma cells. (Mol Cancer Res 2008;6(12):1937–45)

Synthetic siRNA targeting the breakpoint of EWS/Fli-1 inhibits growth of Ewing sarcoma xenografts in a mouse model

The EWS/Fli‐1 fusion gene, a product of the translocation t(11;22, q24;q12), is detected in 85% of Ewing sarcomas and primitive neuroectodermal tumors. It is thought to be a transcriptional activator that plays a significant role in tumorigenesis. In this study, we developed a novel EWS/Fli‐1 blockade system using RNA interference and tested its application for inhibiting the proliferation of Ewing sarcoma cells in vitro and the treatment of mouse tumor xenografts in vivo. We designed and synthesized a small interfering RNA (siRNA) possessing an aromatic compound at the 3′‐end targeting the breakpoint of EWS/Fli‐1. As this sequence is present only in tumor cells, it is a potentially relevant target. We found that the siRNA targeting EWS/Fli‐1 significantly suppressed the expression of EWS/Fli‐1 protein sequence specifically and also reduced the expression of c‐Myc protein in Ewing sarcoma cells. We further demonstrated that inhibition of EWS/Fli‐1 expression efficiently inhibited the proliferation of the transfected cells but did not induce apoptotic cell death. In addition, the siRNA possessing the aromatic compound at the 3′‐end was more resistant to nucleolytic degradation than the unmodified siRNA. Administration of the siRNA with atelocollagen significantly inhibited the tumor growth of TC‐135, a Ewing sarcoma cell line, which had been subcutaneously xenografted into mice. Moreover, modification of the 3′‐end with an aromatic compound improved its efficiency in vivo. Our data suggest that specific downregulation of EWS/Fli‐1 by RNA interference is a possible approach for the treatment of Ewing sarcoma.

EWS/Fli‐1 chimeric fusion gene upregulates vascular endothelial growth factor‐A

Vascular endothelial growth factor (VEGF)‐A plays an important role in the pathological angiogenesis that occurs in soft‐tissue sarcoma and in about half of Ewings sarcoma cases, where it is highly overexpressed. EWS/Fli‐1 is considered to be a transcriptional activator and to play a significant role in tumorigenesis of Ewings sarcoma. However, the relationship between EWS/Fli‐1 and VEGF‐A is still unclear. The aim of this research is to investigate the relationship between EWS/Fli‐1 and VEGF‐A, and to determine whether small interfering RNA (siRNA)‐targeting of VEGF‐A can be developed as a novel treatment for Ewings sarcoma. Knockdown of EWS/Fli‐1 using siRNA on a Ewings sarcoma cell line (A673) suppressed VEGF‐A expression, and transfection of EWS/Fli‐1 into a human osteosarcoma cell line increased VEGF‐A expression. To inhibit VEGF‐A secretion from Ewings sarcoma, we developed a chemically synthesized siRNA that targets VEGF‐A. Transfection of the VEGF siRNA into the Ewings sarcoma cell line significantly suppressed VEGF‐A secretion by up to 98% in vitro, compared with a control. In vivo, we established Ewings sarcoma xenograft models and performed intratumoral injection of the siRNA mixed with atelocollagen. We observed that the inhibition of tumor growth occurs in a dose‐dependent manner. Histological examination revealed decreased microvessel density and morphological change around microvessels in the Ewings sarcoma xenografts treated with the siRNA. It is considered that a combination of chemically synthesized siRNA that targets VEGF‐A and atelocollagen might be a novel and effective option for treating Ewings sarcoma that secretes VEGF‐A.

Surgical treatment for cervical myelopathy in patients aged > 80 years.

The surgical outcomes of 13 patients who were diagnosed with cervical spondylotic myelopathy were reviewed retrospectively. Mean patient age at surgery was 83 years. The severity of cervical spondylotic myelopathy was evaluated using the Japanese Orthopaedic Association score. Daily activities were evaluated using the Barthel index. The preoperative JOA score and Barthel index were 7.8 and 63.5, respectively. The mean JOA score and Barthel index maximum recovery rate were 35% and 24%, respectively. The results of this study imply that surgery for patients with cervical spondylotic myelopathy aged > 80 years is warranted.

Acetabular perforation after medial migration of the helical blade through the femoral head after treatment of an unstable trochanteric fracture with proximal femoral nail antirotation (PFNA): a case report.

The proximal femoral nail antirotation is a new generation of intramedullary device for the treatment of trochanteric femoral fractures, having a helical blade rather than a screw for suggested better purchase in osteoporotic bone. However, it is not free of complications. Few reports are available on postoperative perforation of the helical blade through the femoral head as a unique complication of proximal femoral nail antirotation. We report a 79-year-old woman with acetabular perforation after migration of the helical blade through the femoral head after an unstable trochanteric fracture, which was fixed with a proximal femoral nail antirotation.

Malignant solitary fibrous tumor of the lumbar spinal root mimicking schwannoma: a case report

BACKGROUND CONTEXT Malignant solitary fibrous tumors (SFTs) arising from the spinal cord are extremely rare and poorly understood mesenchymal neoplasms. To date, only one malignant SFT located in the spinal canal of the sacrum has been described, but none arising from the lumbar nerve root have been reported. Although most SFTs with benign histological features can be treated by complete surgical excision alone, malignant SFTs may require adjuvant therapy. However, systemic chemotherapy and radiotherapy have not been shown effective in patients with malignant SFTs. PURPOSE To describe a patient with a malignant SFT arising from the lumbar nerve root. STUDY DESIGN A case report and review of literature. METHODS We describe the clinical course of the patient and the radiological and pathological findings of the tumor. The effect of systemic chemotherapy was evaluated and the relevant literature was reviewed. This work has no disclosure of funding and was approved by the Institutional Review Board of Gifu University. RESULTS The tumor had been resected previously at another hospital, but it recurred and showed multiple metastatic lesions on both lungs within 3 months. Although the patient received systemic chemotherapy, both primary and metastatic lesions were found to be stable disease according to Response Evaluation Criteria in Solid Tumors. The patient died due to cachexia 6 months after her first visit. CONCLUSION This patient presented with a highly unusual tumor. Even if a tumor is a dumbbell-shaped mass, similar to a neural tumor, SFT should be considered in the differential diagnosis.

Successful Everolimus Treatment of Kaposiform Hemangioendothelioma With Kasabach-Merritt Phenomenon: Clinical Efficacy and Adverse Effects of mTOR Inhibitor Therapy.

Kasabach-Merritt phenomenon (KMP) is a life-threatening consumptive coagulopathy associated with underlying kaposiform hemangioendothelioma (KHE) in infancy. We describe the case of a 3-month-old girl with KHE complicated by KMP who responded dramatically to treatment with everolimus, a mechanistic target of rapamycin (mTOR) inhibitor. Immunohistochemical expression of mTOR was found in the KHE biopsy specimens, which may explain the improvement of KMP and reduction in KHE tumor size with mTOR inhibitor treatment. This effective use of everolimus may shed light on the emerging role of mTOR signaling in the development and pathogenesis of KHE and KMP.

Transforaminal lumbar interbody fusion for failed Graf ligamentoplasty: a report of two cases

We report 2 cases of transforaminal lumbar interbody fusion for failed Graf ligamentoplasty. Both patients had residual or recurrent low back pain and leg pain after Graf ligamentoplasty, caused by lumbar segmental instability or narrowing of their intervertebral foramens. The pain improved markedly after the revision surgery. We recommend transforaminal lumbar interbody fusion for failed Graf ligamentoplasty, as it provides rigid interbody bony fusion and obviates complete exposure of the dural sac or dural tube.

Everolimus for Treatment of Pseudomyogenic Hemangioendothelioma

Pseudomyogenic hemangioendothelioma (PMH) is a recently described vascular neoplasm that occurs most commonly in the soft tissue of the distal extremities of young adults. Metastatic PMH can be fatal and there are no effective medications. We describe a case of a 15-year-old boy with metastatic PMH, who responded to treatment with everolimus, a mammalian target of rapamycin inhibitor. Immunohistochemistry showed that mammalian target of rapamycin was expressed in PMH biopsy specimens, which may explain the reduction in PMH tumor size following treatment.

Feasibility and efficacy of gemcitabine and docetaxel combination chemotherapy for bone and soft tissue sarcomas: multi-institutional retrospective analysis of 134 patients

BackgroundBone and soft tissue sarcomas (BSTS) are rare malignant tumors. Recently, the combination of gemcitabine and docetaxel (GD) was shown to have activity as second-line setting in BSTS. However, the efficacy as first-line and adjuvant settings and precise profiles of adverse events in Japanese patients are not known yet. In the present study, the feasibility and efficacy of GD in patients with BSTS were investigated.MethodsPatients with BSTS treated with GD in our institutions were retrospectively analyzed. Information regarding clinical features, adverse events, and outcome was collected and statistically studied. Factors related to survival were analyzed using log-rank test and Cox proportional hazard regression method.ResultsA total of 134 patients were analyzed. GD was carried out as adjuvant setting in 9, first-line in 23, second-line in 56, and third-or-greater line in 46 patients. The response rate (RR) for all patients was 9.7%. RR for the patients treated as adjuvant or first-line setting was 18.8%, whereas that as second-or-greater line was 6.9%. The median progression-free survival (PFS) and overall survival (OS) of all patients were 4.8 (95% CI 3.5–6.1) and 16.4 (95% CI 9.8–22.9) months, respectively. Survival tended to be better in the patients treated as first-line than in those treated as second-or-greater line. Multivariate analysis demonstrated that history of prior chemotherapy (p = 0.046) and response to GD (p = 0.009) was significantly associated with PFS and OS, respectively. The leucopenia and neutropenia were the most frequent adverse events, and grade 3 or 4 leucopenia and neutropenia were observed in 69.4 and 72.4% of the patients. Grade 2 or 3 pneumonitis was observed in one (0.7%) and four (3.0%) patients, respectively. All the patients with pneumonitis had experienced prior chemotherapy and/or radiotherapy.ConclusionsGD used as both first- and second/later line is effective chemotherapy for a proportion of patients with advanced BSTS. Higher response rate and better outcome was achieved in chemotherapy-naïve patients. This regimen is associated with high incidence of severe hematological toxicity, as well as the risk of severe pneumonitis, especially in pre-treated patients. GD is promising for further analysis by phase III study for the patients with BSTS.