DDIT3-amplified or low-polysomic pleomorphic sarcomas without MDM2 amplification: Clinicopathological review and immunohistochemical profile of nine cases

Several high-grade pleomorphic sarcoma cases that cannot be classified into any existing established categories have been reported. These cases were provisionally classified into undifferentiated pleomorphic sarcoma (UPS). Some dedifferentiated liposarcoma (DDLS) cases may also have been classified into the UPS category due to the absence of MDM2 amplification or an atypical lipomatous tumor/well-differentiated liposarcoma component. We retrieved and reviewed 77 high-grade pleomorphic sarcoma cases, initially diagnosed as UPS in 66 cases and DDLS in 11 cases. Fluorescence in situ hybridization (FISH) analyses of DDIT3 and MDM2 were performed for available cases. Of the cases successfully subjected to DDIT3 FISH (n = 56), nine (7 UPS and 2 DDLS) showed DDIT3 amplification but no MDM2 amplification. Two UPS cases showed both telomeric (5') and centromeric (3') amplification of DDIT3 or low polysomy of chromosome 12, whereas 5 UPS and 2 DDLS cases showed 5'-predominant DDIT3 amplification. Histopathologically, all cases showed UPS-like proliferation of atypical pleomorphic tumor cells. Immunohistochemically, only one case showed focal nuclear positivity for DDIT3, supporting the previous finding that DDIT3 expression was not correlated with DDIT3 amplification. All three cases with focal MDM2 expression involved 5'-predominant amplification, two of which showed DDLS-like histological features. The majority of cases (7/9) showed decreased expression in p53 staining, suggesting that DDIT3 amplification regulates the expression of TP53 like MDM2. From a clinicopathological perspective, we hypothesize that DDIT3-amplified sarcoma, especially with 5'-predominant amplification, can be reclassified out of the UPS category.

Myxoid liposarcoma in an 11-year-old patient

Myxoid liposarcoma is a mesenchymal malignancy that most commonly presents in young adults, with peak incidence between the ages of 30-50 years. The clinical behavior of myxoid liposarcoma has been well characterized in adults. However, little is known about the clinical features and treatment outcomes of myxoid liposarcoma in child, owing to its rarity. This case report describes an 11-year-old previously healthy female who presented with a painless mass in her right thigh. Ultrasonography, computed tomography, and magnetic resonance imaging demonstrated a soft tissue mass with clear margins in the subfascial plane superficial to the gracilis and sartorius muscles. She was diagnosed with myxoid liposarcoma based on histological and molecular cytogenetic examinations of the core-needle biopsy specimen. The patient subsequently underwent wide resection without any adjuvant treatment. The patient has not experienced any symptoms of local recurrence and metastases as of 2.5 years after surgery.

Nuclear β-catenin translocation plays a key role in osteoblast differentiation of giant cell tumor of bone

Denosumab is a game-changing drug for giant cell tumor of bone (GCTB); however, its clinical biomarker regarding tumor ossification of GCTB has not been elucidated. In this study, we investigated the relationship between Wnt/β-catenin signaling and the ossification of GCTB and evaluated whether endogenous nuclear β-catenin expression predicted denosumab-induced bone formation in GCTB. Genuine patient-derived primary GCTB tumor stromal cells exhibited osteoblastic characteristics. Identified osteoblastic markers and nuclear β-catenin translocation were significantly upregulated via differentiation induction and were inhibited by treating with Wnt signaling inhibitor, GGTI-286, or selective Rac1-LEF inhibitor, NSC23766. Furthermore, we reviewed the endogenous ossification and nuclear β-catenin translocation of 86 GCTB clinical samples and elucidated that intra-tumoral ossification was significantly associated with the nuclear translocation. Three-dimensional quantitative analyses (n = 13) of tumoral CT images have revealed that the nuclear β-catenin translocation of naïve GCTB samples was significantly involved with the denosumab-induced tumor ossification. Our findings suggest a close relationship between the nuclear β-catenin translocation and the osteoblastic differentiation of GCTB. Investigations of the nuclear β-catenin in naïve GCTB samples may provide a promising biomarker for predicting the ossification of GCTB following denosumab treatment.

Successful Management of Radiation-Associated Insufficiency Fracture of the Tibial Plateau with Low-Intensity Pulsed Ultrasound

Patient: Female, 52-year-old

Final Diagnosis: Fracture

Symptoms: Knee pain

Medication:—

Clinical Procedure: —

Specialty: Oncology

Does the Use of Peripheral Immune-Related Markers Indicate Whether to Administer Pazopanib, Trabectedin, or Eribulin to Advanced Soft Tissue Sarcoma Patients?

Pazopanib, trabectedin, and eribulin are administered for the treatment of soft tissue sarcomas (STSs); however, there is little consensus on which agent should be preferentially used in a clinical setting. This study assessed whether peripheral immune-related markers served as a useful reference when selecting pazopanib, trabectedin, or eribulin. This study included 63 patients who were administered pazopanib, trabectedin, or eribulin for advanced STSs between March 2015 and December 2020. Patients were divided into three groups based on the first drug administered among these three drugs. Differences in overall survival (OS) or progression-free survival (PFS) among the three groups were analyzed. OS showed no significant differences among the drugs administered first. For patients with low neutrophil-to-lymphocyte ratio (NLR), the OS of patients administered pazopanib as the first choice was shorter than the others (hazard ratio [HR] = 9.53, 95% confidence interval [CI] = 1.94–18.13, p = 0.0018). In the low platelet-to-lymphocyte ratio (PLR) subgroup, the OS of the patients administered eribulin for the first choice was longer than that of the others (HR = 0.32, 95%CI = 0.10–0.98, p = 0.046). Therefore, NLR and PLR might be used as prognostic indicators to dictate whether STS patients receive pazopanib, trabectedin, or eribulin.

Giant Cell Tumor of Bone of the First Rib Successfully Treated with Combined Preoperative Denosumab Therapy and Surgery via a Transmanubrial Approach

Patient: Female, 27-year-old

Final Diagnosis: Giant cell tumor of bone

Symptoms: No symptom

Medication:—

Clinical Procedure: —

Specialty: Oncology

Malignant Transformation of Giant Cell Tumor of Bone 7 years After Initial Surgery: A Case Report and Literature Review

CASE

A 64-year-old man with a history of giant cell tumor of bone (GCTB) in the fibula 7 years earlier developed a recurrence with histologic features of osteosarcoma. Both the primary GCTB and the secondary osteosarcoma were found to have the H3F3A gene mutation. Despite immediate above-the-knee amputation, the patient died of respiratory failure because of lung metastases 3 months later.

CONCLUSION

This is the first report of proven H3F3A mutation in both the primary GCTB and the secondary osteosarcoma in the same case. Clinicians should consider secondary malignancy in patients presenting with a lesion at the site of a previously treated GCTB after a long interval.

Cardiac Tamponade as an Unusual Initial Clinical Manifestation of CIC-DUX4 Sarcoma

Patient: Male, 48-year-old

Final Diagnosis: Cardiac tamponade

Symptoms: Hypotension • tachycardia

Medication: —

Clinical Procedure: —

Specialty: Oncology

Risk factors of local recurrence after surgery in extraabdominal desmoid-type fibromatosis: A multicenter study in Japan

This study was undertaken to clarify the risk factors, including the mutation status of CTNNB1, for the local recurrence after surgery of the rare disease desmoid‐type fibromatosis. It was designed as a multiinstitutional joint research project with 7 major centers in Japan participating. The committee members of 7 major medical centers specializing in bone and soft tissue tumors formed this study group to develop clinical care guidelines. Of 196 cases with specimens and medical records collected from the 7 institutions, 88 surgically treated ones were analyzed regarding clinicopathologic prognostic factors including CTNNB1 mutation status. Excluding R2 cases (n = 3), 5‐year local recurrence‐free survival (LRFS) was 52.9%. No case had received pre‐ or postoperative radiotherapy. Univariate analysis revealed that extremity location (P < .001) and larger size (8 cm or more, P = .036) were significant adverse risk factors for LRFS. Multivariate analysis indicated that extremity location (P < .001) was a significantly adverse factor in addition to recurrent tumor (P = .041), S45F mutation (P = .028), and R1 surgical margin (P = .039). Preoperative drug treatment, including nonsteroidal antiinflammatory drugs, did not reduce the incidence of local recurrence (P = .199). This is the first study to analyze the factors correlating with outcomes of surgical treatment, including CTNNB1 mutation status, in a relatively large number of cases from an Asian country. Tumor location was found to be the most influential prognostic factor for local recurrence, similar to the results from Europe and North America. The development of more sensitive method(s) for determination of CTNNB1 mutation is a priority for future study.

Definitive radiation therapy in patients with unresectable desmoid tumors: a systematic review

Background

Desmoid tumors are rare soft tissue tumors. Wide local excision has been the standard surgical treatment for desmoid tumors. However, this procedure results in high local recurrence rates, so non-surgical treatments should be considered. The aim of this systematic review was to evaluate the effect of radiation therapy on patients with desmoid tumors, especially those with unresectable disease.

Methods

We evaluated studies published between 1 January 1990 and 31 August 2017 and cited in PubMed and Ichushi (in Japanese). All studies evaluating the effect of radiation therapy on desmoid tumors were included. Data regarding radiation dose, recurrence and adverse events were recorded.

Results

Among 218 identified studies, only 6 were finally included in this review. Local control was achieved in 253 of 317 patients with unresectable or unresected tumors who underwent definitive radiation therapy (the crude rate of local control was 79.8%). Toxicity was evaluated in patients who underwent definitive radiation therapy or surgery plus radiation therapy. One of the most common acute complications was skin toxicity. Frequent late complications of radiation therapy included fibrosis/contracture/joint stiffness, skin disorders, lymphedema and pain. Six patients developed secondary malignancies in the radiation field.

Conclusions

In patients treated unsuccessfully with surgery, watchful waiting and pharmacotherapy, radiation therapy may be an option as salvage therapy because of the high rate of local control. Because desmoid tumors frequently develop in young individuals, children and young patients who receive radiation therapy for the treatment of desmoid tumors should be followed up on a long-term basis with periodic monitoring for late radiation toxicities.

Analysis of a limb-specific regulatory element in the promoter of the link protein gene

Link protein is encoded by the Hapln1 gene and is a prototypical protein found in the cartilage matrix. It acts as an important component of the endochondral skeleton during early development. To study its transcriptional regulation, promoter fragments derived from the link protein gene were coupled to the β-galactosidase reporter and used to study in vivo transgene expression in mice. In day 15.5 mouse embryos, a link promoter fragment spanning -1020 to +40 nucleotides demonstrated highly specific β-galactosidase staining of skeletal structures, including the appendicular and axial cartilaginous tissues. Two shorter promoter fragments, spanning -690 to +40 and -315 to +40 nucleotides, demonstrated limb- and genitalia-specific expression resembling that of homeodomain-regulated tissues. Bioinformatic analysis revealed a highly conserved, Hox-like binding site (HLBS) at approximately -220 bp of the promoter, shared by both constructs, which contained the Hox-core consensus sequence TAATTA. Electromobility shift assays demonstrated binding of Hox-B4 recombinant protein to the HLBS, which was eliminated with nucleotide substitutions within the core-binding element. Co-transfection analysis of the HLBS demonstrated a 22-fold transcriptional activation by HoxA9 expression, which was ablated with a substitution within the core HLBS element. Together these findings establish promoter regions within the link protein gene that are important for in vivo expression and identify the potential role of homeodomain-containing proteins in controlling cartilage and limb gene expression.

Is immunohistochemical staining for β-catenin the definitive pathological diagnostic tool for desmoid-type fibromatosis? A multi-institutional study

Immunohistochemical staining with anti-β-catenin antibody has been applied as a diagnostic tool for desmoid-type fibromatoses (DFs). In recent years, specific gene mutation (CTNNB1) analysis has also been reported to be useful for diagnosis of DF; however, the association between CTNNB1 mutation status and immunohistochemical staining pattern of β-catenin is rarely reported. The purposes of this study are to clarify the relationship of the staining pattern of β-catenin with the CTNNB1 mutation status and various clinical variables, and to investigate the significance of immunohistochemical staining of β-catenin in cases diagnosed as DF. Between 1997 and 2017, 104 cases diagnosed as DF from 6 institutions in Japan were enrolled in this study: Nagoya University, National Cancer Center Hospital, Niigata University, Okayama University, Kyushu University, and Cancer Institute Hospital. For all cases, immunohistochemical staining of β-catenin and gene mutation analysis of CTNNB1 were performed. Of 104 cases, 87 (84%) showed nuclear staining of β-catenin, and 95 (91%) showed positive staining in the cytoplasm. The proportion of cases showing strong nuclear staining of β-catenin was significantly higher in the cases with S45F than in those with T41A or wild type. The proportion of cases stained strongly in the cytoplasm rather than in the nucleus was significantly higher in the group of T41A than that of S45F or wild type. Among 17 cases in which nuclear immunostaining was absent, CTNNB1 mutation was observed in 5 cases (29.4%). There were unignorable cases of DF with negative β-catenin immunostaining despite a definitive clinical and pathological diagnosis of DF and/or positive CTNNB1 mutation.

Methotrexate-Related Lymphoproliferative Disorder Presenting with Severe Swelling of the Elbow Joint: A Case Report

CASE

A patient with rheumatoid arthritis (RA) who was being treated with methotrexate (MTX) therapy presented with severe swelling of the left elbow. Magnetic resonance imaging showed a tumor-like lesion around the elbow joint. Fluorodeoxyglucose positron emission tomography indicated multiple lesions in the lung and the lymph nodes. An open biopsy of a cervical lymph node was performed, and MTX-related lymphoproliferative disorder (MTX-LPD) was diagnosed. After cessation of the MTX therapy, the elbow swelling regressed, and the patient was in remission of MTX-LPD.

CONCLUSION

MTX-LPD should be considered in the differential diagnosis when a patient with RA develops severe joint swelling while on MTX therapy.

Correction: Hypoxia-inducible factor 1 alpha is a poor prognostic factor and potential therapeutic target in malignant peripheral nerve sheath tumor

[This corrects the article DOI: 10.1371/journal.pone.0178064.].

Factors associated with the decision of operative procedure for proximal femoral bone metastasis: Questionnaire survey to institutions participating the Bone and Soft Tissue Tumor Study Group of the Japan Clinical Oncology Group

BACKGROUND

Pathological fracture of the proximal femur is a main cause of cancer patients losing their ability to walk. Although both osteosynthetic devices (predominantly intramedullary nails) and prosthetic replacement have been widely performed for treatment, controversies exist regarding which procedure should be used for the various conditions. In order to decide the eligibility criteria of a planned randomized prospective study about the treatment of pathological fractures of the proximal femur, we assessed the factors affecting the selection of operative procedures using questionnaires sent to the members of the Bone and Soft Tissue Tumor Study Group (BSTTSG) of the Japan Clinical Oncology Group (JCOG).

METHODS

Questionnaire surveys to evaluate (1) the priority levels of the factors, (2) the equipoise range of each factor in situations where either procedure could be applied, (3) risk and benefit of each procedure, and (4) the degree of bone destruction affecting the selection of operative procedures, were sent to 26 institutions.

RESULTS

Over 80% of the institutions answered. Orthopaedic surgeons of BSTTSG decided on the procedure according to the following factors in descending order: life expectancy, performance status before fracture, the degree of bone destruction, walking ability before fracture, general complications, the number of bone metastases in other sites, and the visceral metastasis status. With regard to bone destruction, (1) the involvement of the head, neck, calcar, and intertrochanteric region, (2) transverse destruction >1/2, and (3) soft-tissue tumor extension, were the factors that led to the choice of prosthesis treatment.

CONCLUSIONS

Using these identified factors, the inclusion criteria for the prospective randomized study of the surgical treatment of metastatic bone tumors of the proximal femur were optimized. The evaluation system about the bone destruction of metastases needs to be refined through the following prospective randomized study.

Hypoxia-inducible factor 1 alpha is a poor prognostic factor and potential therapeutic target in malignant peripheral nerve sheath tumor

Background

Malignant peripheral nerve sheath tumor (MPNST) is a rare soft tissue sarcoma with poor prognosis. Hypoxia-inducible factor 1 (HIF-1) plays a crucial role in the cellular response to hypoxia and regulates the expression of multiple genes involved in tumor progression in various cancers. However, the importance of the expression of HIF-1α in MPNSTs is unclear.

Methods

The expression of HIF-1α was examined immunohistochemically in 82 MPNST specimens. Cell culture assays of human MPNST cells under normoxic and hypoxic conditions were used to evaluate the impact of anti-HIF-1α–specific siRNA inhibition on cell survival. A screening kit was employed to identify small molecules that inhibited HIF-1α.

Results

The nuclear expression of HIF-1α was positive in 75.6% of MPNST samples (62/82 cases). Positivity for HIF-1α was a significant poor prognostic factor both in univariate (P = 0.048) and multivariate (P ≤ 0.0001) analyses. HIF-1α knockdown abrogated MPNST cell growth, inducing apoptosis. Finally, chetomin, an inhibitor of HIF-1α, effectively inhibited the growth of MPNST cells and induced their apoptosis.

Conclusion

Inhibition of HIF-1α signaling is a potential treatment option for MPNSTs.

Efficacy analysis of the aprepitant-combined antiemetic prophylaxis for non-round cell soft-tissue sarcoma patients received adriamycin and ifosfamide therapy

Appropriate antiemetic prophylaxis for moderately emetogenic chemotherapy in patients with non-round cell soft-tissue sarcomas (NRC-STS) remains unclear. We retrospectively investigated efficacy and safety of aprepitant-combined antiemetic prophylaxis in patients with NRC-STS receiving adriamycin plus ifosfamide (AI) therapy. Forty NRC-STS patients were enrolled, their median age was 50 years (range 18-74), and 13 (32.5%) were female. Median cycle number of AI therapy was 4. Twenty patients received the doublet antiemetic prophylaxis (5-hydroxytryptamine-3 receptor antagonist and dexamethasone), and 20 received triplet (5-hydroxytryptamine-3 receptor antagonist, dexamethasone, and aprepitant). In the overall period, complete response rate for nausea and emesis in the triplet group was significantly higher than that in the doublet group (70% vs 35%; P = 0.027). Patients with no-emesis in the overall period were more frequently observed in the triplet group than in the doublet group (90% vs 65%; P = 0.058). All toxicities other than emesis were almost equivalent in both the groups. These results suggest that a triplet antiemetic prophylaxis may be optimal in the treatment with AI therapy for NRC-STS.

Bone and soft tissue tumors presenting as sciatic notch dumbbell masses: A critical differential diagnosis of sciatica

AIM

To study the clinical findings and characteristic features in sciatic notch dumbbell tumors (SNDTs).

METHODS

We retrospectively reviewed the clinical outcomes and characteristic features of consecutive cases of SNDTs (n = 8).

RESULTS

Buttock masses occurred in three patients with SNDT (37.5%). Severe buttock tenderness and pain at rest were observed in seven patients with SNDTs (87.5%). Remarkably, none of the patients with SNDTs experienced back pain. Mean tumor size was 8.4 ± 2.0 cm (range, 3.9 to 10.6 cm) and part of the tumor mass was detected in 2 patients in the sagittal view of lumbar magnetic resonance imaging (MRI).

CONCLUSION

The clinical information regarding to SNDTs is scarce. The authors consider that above mentioned characteristic findings may facilitate the suspicion of pelvic pathology and a search for SNDT by MRI or computed tomography should be considered in patients presenting with sciatica without evidence of spinal diseases.

Tumor-induced osteomalacia caused by a massive phosphaturic mesenchymal tumor of the acetabulum: A case report

We report a case of tumor-induced osteomalacia (TIO) caused by a massive phosphaturic mesenchymal tumor (PMT) of the acetabulum. A 68-year-old woman presented with progressive bone pain of the rib cage, and polyarthralgia and back pain for 3 years. She was diagnosed with hypophosphatemic osteomalacia because laboratory testing was remarkable for low serum phosphorus and a low level of 1,25(OH)2 vitamin D. Three years later, her hip radiograph revealed an osteolytic lesion of the acetabulum. Magnetic resonance imaging of the acetabulum showed a massive lesion. Laboratory data showed hypophosphatemia and an elevated serum level of fibroblast growth factor 23 (FGF-23). Samples obtained with open biopsy showed a low-grade spindle cell neoplasm with FGF-23 positivity, identified by using immunohistochemical staining, confirming the diagnosis of a PMT mixed connective tissue variant. Curettage of the tumor was performed, and the defects were filled with bone allografts. The hip joint was reconstructed with total hip arthroplasty using a Muller support ring. To our knowledge, this report represents the first documented case of massive PMT of the acetabulum causing TIO.

Expression of Forkhead box M1 in soft tissue leiomyosarcoma: Clinicopathologic and in vitro study using a newly established cell line

Leiomyosarcoma (LMS) of soft tissue is a sarcoma with smooth‐muscle differentiation, and conventional chemotherapy does not improve its outcome. The application of novel antitumor agents and precise prognostication has been demanded. The expression of the protein Forkhead box M1 (FOXM1), a member of the FOX family, is considered an independent predictor of poor survival in many cancers and sarcomas. However, the expression status of FOXM1 in LMS is poorly understood. The purposes of this study were to examine the correlation between the expression of FOXM1 and clinicopathologic or prognostic factors and to clarify the efficacy of FOXM1 target therapy in LMS. We evaluated the immunohistochemical expressions of FOXM1 using 123 LMS tumor specimens. Univariate and multivariate survival analyses revealed that FOXM1 expression was associated with poor prognosis in LMS. An in vitro study was then carried out to examine the antitumor effect of a FOXM1 inhibitor (thiostrepton) and siRNA on a novel LMS cell line, TC616. We also assessed the efficacy of the combined use of doxorubicin and thiostrepton. Thiostrepton showed dose‐dependent antitumor activity and TC616 cells treated with the combination of thiostrepton and doxorubicin showed lower proliferation compared to those treated with either drug individually. FOXM1 interruption by siRNA decreased cell proliferation and increased chemosensitivity. In conclusion, FOXM1 has potential to be a therapeutic target for LMS.

Intraosseous hemangioma arising in the clavicle

Intraosseous hemangioma (IH) is commonly seen in the vertebral column and skull: however, IH occurring in the appendicular skeleton, including the clavicle, is uncommon. We herein report the case of a 69-year-old female presenting with IH of the left clavicle. The findings of preoperative imaging studies, including radiographs, computed tomography (CT), magnetic resonance imaging, fluorine-18-fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT and ultrasonography, are described. In particular, (18)F-FDG PET/CT showed an ill-defined osteolytic lesion with abnormally high FDG uptake. Surgical en bloc resection with preoperative embolization was carried out and a histopathological examination confirmed the presence of an intraosseous cavernous hemangioma in the clavicle.

Low-grade central osteosarcoma arising from bone infarct

Bone infarct-associated sarcoma is a rare sarcoma, accounting for less than 1% of all bone sarcomas. Its histology usually reflects a high-grade sarcoma, such as malignant fibrous histiocytoma of bone or conventional osteosarcoma. Low-grade sarcoma arising from bone infarct has not been described well in the literature. Here, we present a 17-year follow-up of a female patient with bone infarct in her right humerus, from which a low-grade central osteosarcoma developed during follow-up. A histologic diagnosis of low-grade central osteosarcoma was confirmed by immunohistochemical expression of MDM2 and CDK4. She underwent a wide resection surgery. As of 4 years after surgery, she has remained free of any evidence of recurrence or metastasis. Here, we present clinical and pathologic findings of our case in detail and discuss the differential diagnoses of this extremely rare condition.

Minimally invasive solid long segmental fixation combined with direct decompression in patients with spinal metastatic disease

This study seeks to discuss the efficiency of minimally invasive surgery of posterior long segmental fixation plus direct decompression in patients with spinal metastatic tumors. Twenty-five patients received minimally invasive surgery of long segmental fixation combined with direct decompression from posterior approach. Pain and neurologic improvement in these patients pre- and post operation were evaluated by Denis' Pain Scale and Frankel Score, respectively. Seventeen patients (68.0%) showed significant decreases in Denis' Pain score after surgery (p < 0.0001). Paralysis symptoms were improved in nineteen patients (76.0%). The Frankel Score exhibited significant difference between pre-operation and post-operation (p < 0.0001). Operation time and blood loss in this cohort were 324 ± 90 min and 1047 ± 730 ml, respectively. No fatal complications were observed as a result of surgery. In conclusion, minimally invasive surgery of posterior long segmental fixation combined with direct decompression is a safe and efficient strategy to release pain and improve neurological function in patients with spinal metastatic tumors.

Perlecan modulates VEGF signaling and is essential for vascularization in endochondral bone formation

Perlecan (Hspg2) is a heparan sulfate proteoglycan expressed in basement membranes and cartilage. Perlecan deficiency (Hspg2(-/-)) in mice and humans causes lethal chondrodysplasia, which indicates that perlecan is essential for cartilage development. However, the function of perlecan in endochondral ossification is not clear. Here, we report the critical role of perlecan in VEGF signaling and angiogenesis in growth plate formation. The Hspg2(-/-) growth plate was significantly wider but shorter due to severely impaired endochondral bone formation. Hypertrophic chondrocytes were differentiated in Hspg2(-/-) growth plates; however, removal of the hypertrophic matrix and calcified cartilage was inhibited. Although the expression of MMP-13, CTGF, and VEGFA was significantly upregulated in Hspg2(-/-) growth plates, vascular invasion into the hypertrophic zone was impaired, which resulted in an almost complete lack of bone marrow and trabecular bone. We demonstrated that cartilage perlecan promoted activation of VEGF/VEGFR by binding to the VEGFR of endothelial cells. Expression of the perlecan transgene specific to the cartilage of Hspg2(-/-) mice rescued their perinatal lethality and growth plate abnormalities, and vascularization into the growth plate was restored, indicating that perlecan in the growth plate, not in endothelial cells, is critical in this process. These results suggest that perlecan in cartilage is required for activating VEGFR signaling of endothelial cells for vascular invasion and for osteoblast migration into the growth plate. Thus, perlecan in cartilage plays a critical role in endochondral bone formation by promoting angiogenesis essential for cartilage matrix remodeling and subsequent endochondral bone formation.

The mechanism of cross-resistance to proteasome inhibitor bortezomib and overcoming resistance in Ewing's family tumor cells

EWS-Fli1 plays important roles in oncogenesis of Ewing's family tumors (EFTs). We have reported that EWS-Fli1 inhibits p21(waf1/cip1) and p27(kip1) expressions, which are degraded by the ubiquitin-proteasome pathway. Bortezomib efficiently up-regulated p21(waf1/cip1) and p27(kip1) expression, and induced apoptosis accompanied by the expression of cleaved-PARP, DR4 and activated caspase-8 in EFT cells. Since most EFTs deaths result from the tumor being resistant to chemotherapeutic drugs, the effects of novel anti-tumor reagents on drug-resistant tumors were next investigated. The results demonstrated that the drug-resistant EFT clones were cross-resistant to bortezomib probably due to the over-expression of the efflux pumps, P-glycoprotein and MRP1. We further investigated whether the efflux pump inhibitors would modulate the effects of bortezomib. The combination of P-gp-specific or MRP1-specific inhibitors could enhance the anti-tumor effects of bortezomib on the drug-resistant clones. These data suggest that bortezomib might be a substrate of P-gp and MRP1. Although bortezomib would be effective on the primary EFTs, it is necessary to pay attention to the resistance to bortezomib in clinical trials for the advanced cases. The combination of bortezomib and the efflux pump inhibitors might be a promising method as a novel molecular target therapy for advanced EFTs.

The Effects of Histone Deacetylase Inhibitors on the Induction of Differentiation in Chondrosarcoma Cells

PURPOSE

Histologically, chondrosarcomas represent the degree of chondrogenic differentiation, which is associated with the prognosis of the disease. Histone acetylation and deacetylation play key roles in the regulation of chondrocytic differentiation. Here, we describe the antitumor effects of histone deacetylase (HDAC) inhibitors as differentiating reagents on chondrosarcomas.

EXPERIMENTAL DESIGN

We examined the effects of a HDAC inhibitor, depsipeptide, on the growth of chondrosarcoma cell lines. We also investigated the modulation of the expression levels of extracellular matrix genes and the induction of phenotypic change in chondrosarcoma cells treated with depsipeptide. Finally, we examined the antitumor effect of depsipeptide on chondrosarcoma in vivo.

RESULTS

Depsipeptide inhibited the growth of chondrosarcoma cells by inducing cell cycle arrest and/or apoptosis. HDAC inhibitors increased the expression of the alpha1 chain of type II collagen (COL2A1) gene due to the enhanced histone acetylation in the promoter and enhancer. Depsipeptide also up-regulated the expressions of aggrecan and the alpha2 chain of type XI collagen (COL11A2) mRNA in a dose-dependent manner. Moreover, long-term treatment with a low dose of depsipeptide resulted in the induction of differentiation into hypertrophic phenotype, as shown by the increment of the alpha1 chain of type X collagen (COL10A1) expression in chondrosarcoma cells. In vivo studies and histologic analyses confirmed that depsipeptide significantly inhibited tumor growth and induced differentiation into the hypertrophic and mineralized state in chondrosarcoma cells.

CONCLUSIONS

These results strongly suggest that HDAC inhibitors may be promising reagents for use as a differentiating chemotherapy against chondrosarcomas.

The extramedullary guide of the proximal tibia resection should be seen straight in front during total knee arthroplasty

If surgeons see the shaft of the extramedullary guide from lateral to the guide during preparation of the proximal tibia resection during total knee arthroplasty, the tibial component may be implanted in varus position in the frontal plane. In order to clarify the effect of the angle of the surgeons' sight relative to the sagittal plane and the posterior slope angle of the resected surface on varus position of the tibial component in the frontal plane, mathematical analysis was performed. Three-dimensional coordinate system was utilized so that the central axis of the tibial shaft on the Z-axis and the shaft of the guide were skew. The relationship between two lines was analyzed solving equations on three dimensional planes. When the posterior slope angle is 10 degrees, and if surgeons see the shaft of the guide 10 degrees, 20 degrees and 30 degrees lateral to the sagittal plane, and the shaft and the central axis of the tibial shaft would seem to be parallel, the true varus tilt angle of the shaft on the frontal plane is 1.8 degrees, 3.7 degrees and 5.8 degrees, respectively. The extramedullary guide should be seen straight in front of the guide.

Focal adhesion kinase is activated in invading fibrosarcoma cells and regulates metastasis

Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase that is overexpressed in several human cancers, and induces survival, proliferation and motility of cells in culture. Phosphorylation of FAK has been studied extensively in vitro, but little is known about its regulation during tumor invasion in vivo. In the current study, green fluorescent protein (GFP) was expressed stably in an invasive murine fibrosarcoma cell line for the purpose of discrimination between tumor and normal cells. Under fluorescence microscopy, the tumor was highly fluorescent, and the margin between the tumor and normal tissue was clearly demarcated. Using this invasion model, we showed localization of pY397-FAK expression in the infiltrative edge of tumors. We reproduced local invasion in vivo using a tumor tissue culture method in a three dimensional collagen gel. Phosphorylation of FAK is also upregulated in invading fibrosarcoma cells under in vitro conditions. Expression of the FAK C-terminal domain termed FRNK (FAK-related non-kinase) in 2,472 cells decreased FAK phosphorylation without changing total FAK levels. FRNK inhibited the motility of 2,472 cells, and reduced invasion in vitro. Although FRNK did not affect cell growth, it inhibited experimental metastases in syngenic mice. These results demonstrate that the phosphorylation of FAK might be specifically upregulated in invading fibrosarcoma cells and regulate their invasion and metastasis.

The possible role of EWS-Fli1 in evasion of senescence in Ewing family tumors

The chromosomal translocation t(11;22) yields the EWS-Fli1 fusion gene and is associated with oncogenesis of Ewing family tumors (EFT). In this study, using the RNA interference method, we show that EWS-Fli1-targeting small interfering RNAs (siRNA) depleted EWS-Fli1 protein and caused growth inhibition in EFT cells with the accumulation of p27 protein and the down-regulation of Skp2 protein in dose-dependent, time-dependent, and sequence-specific manners. Depletion of EWS-Fli1 subacutely elicited a senescence-like phenotype, but not apoptosis, in EFT cells. Furthermore, not only the knockdown of p27, but also the forced expression of Skp2, reduced the expression levels of p27 protein and partially rescued senescence-like phenotype caused by EWS-Fli1-targeting siRNAs. The accumulation of p27 protein in EWS-Fli1-depleted cells inhibited cdk2 kinase activity and was related to the stability of p27 protein, which resulted from a decrease in Skp2 protein. Immunohistochemical analysis of p27 and Skp2 proteins in EFT samples revealed that there was an inverse relationship between the expression profiles of p27 and Skp2 proteins. These findings indicate an important role of EWS-Fli1 in the prevention of senescence, leading to the unlimited growth and oncogenesis of EFT cells through a decrease in the stability of p27 protein due to increased action of Skp2-mediated 26S proteasome degradation.

Involvement of P-glycoprotein and MRP1 in resistance to cyclic tetrapeptide subfamily of histone deacetylase inhibitors in the drug-resistant osteosarcoma and Ewing's sarcoma cells

Despite recent improvements in multimodal therapies for osteosarcoma (OS) and Ewing's family of tumors (EFTs), the prognosis of relapsed cases remains very poor because of the resistance to chemotherapy. Histone deacetylase inhibitors (HDACIs), including members of the cyclic tetrapeptide family such as FK228 and apicidin, are novel antitumor agents that can induce cell cycle arrest and apoptosis in various cancer cells. HDACIs also exhibit potent antitumor effects on OS and EFTs. However, to date there have been no studies to our knowledge reporting the effects of HDACIs on drug-resistant OS and EFTs. Here, we demonstrated that FK228 and apicidin exhibited strong resistance in doxorubicin-resistant clones of OS and EFTs expressing P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) and that P-gp and MRP1 might play a crucial role in the resistance mechanism to FK228 and apicidin. A P-gp inhibitor (verapamil) and an MRP1 inhibitor (MK571) could independently reverse the resistance to FK228 and apicidin in the drug-resistant clones. Moreover, the combination of verapamil and MK571 could enhance HDACI-induced cell number reduction in drug-resistant clones to a similar extent as that in their parental clones. Although these findings suggest the difficulty in treating drug-resistant tumors expressing P-gp and/or MRP1 with these HDACIs, the combination of P-gp and MRP1 inhibitors might reverse the resistance to the HDACIs in the treatment of those tumors. Because HDACIs are potent and promising antitumor drugs and seem to be close to clinical use, it is necessary to pay attention to the resistance mechanisms against HDACIs.

Improvement of production of Kojic acid by a mutant strain Aspergillus oryzae, MK107-39

A strain designated MK107-39, producing kojic acid with a high yield, was obtained by a new screening method using a 96-well microtiter plate after NTG treatment of Aspergillus oryze ATCC 22788. The amount of kojic acid produced by strain MK107-39 in a shaking flask was 28 g/l from 100 g/l of glucose, which was 7.7-times higher than that produced by parent strain. The kojic acid yields per cell and the amount of glucose consumed were 9.8 and 6.0-times higher than those of the parent strain. Based on differences in the use of carbohydrates and organic acids, it seems that strain MK107-39 has some mutation regarding carbohydrate metabolism. By customizing the medium and culture conditions such as glucose concentration, dissolved oxygen concentration and pH of the fermentation broth, more than 110 g/l of kojic acid was produced in a 3-l jar fermentor. Upon scale up to a 600-l pilot fermentor, enhanced production of kojic acid was successfully achieved. The kojic acid yield from glucose consumed, Y(P/S), was 0.43 (g/g) in this pilot plant-scale fermentation.

Antitumor effects of histone deacetylase inhibitor on Ewing's family tumors

A chimeric protein, EWS-Fli1, identified in most Ewing's family tumors (EFTs) has been shown to be associated with the tumorigenicity of EFTs. We have previously reported that p21(Waf1/Cip1) expression was inhibited by EWS-Fli1 in EFTs. Histone deacetylase inhibitors (HDACIs) are known to up-regulate p21(Waf1/Cip1) expression in various cells and show promise as a cancer therapy. Here, we demonstrate the possible involvement of EWS-Fli1 in the activities of both histone acetylation and deacetylation, as well as the potential use of HDACIs as an antitumor agent for EFTs. A novel HDACI, FK228, strongly induced p21(Waf1/Cip1) expression, leading to the hypophosphorylation of retinoblastoma protein (Rb) in EFT cells. Results indicated that EWS-Fli1 deregulated histone acetylation through both the repression of histone acetyltransferase (HAT) and the enhancement of histone deacetylase (HDAC) activities in EFT cells. FK228 treatment blocked both of the abnormal functions of EWS-Fli1. Expressions of EWS-Fli1 protein and mRNA were also inhibited by HDACIs. We suggest that HDACIs might inhibit the expression of EWS-Fli1 via the suppression of the EWS promoter activity. FK228 demonstrated potent growth inhibitory effects on EFT cells at nanomolar concentrations, as well as an apparent distinction in the apoptotic effects between EFT and normal cells. Moreover, intraperitoneal administration of FK228 significantly inhibited tumor growth and induced apoptosis in EFTs in vivo. These results suggest that HDACI might be a promising reagent for use in molecular-based chemotherapy against EFTs.

Transactivation of cyclin E gene by EWS-Fli1 and antitumor effects of cyclin dependent kinase inhibitor on Ewing's family tumor cells

Chromosomal translocation t(11; 22)(q24; q12) is detected in approximately 90% of Ewing's family tumors (EFTs) including Ewing's sarcoma and primitive neuroectodermal tumor. This results in the formation of the EWS-Fli1 fusion gene, which produces EWS-Fli1 fusion protein. This chimerical gene product acts as an aberrant transcriptional activator, which may be responsible for the tumorigenesis of EFTs. We have previously reported that cyclin E expression was upregulated in EFT cells and in EWS-Fli1 transformed fibroblastic cells. However, the mechanism of the overexpression of cyclin E by EWS-Fli1 is still unknown. In our study, we investigated the mechanism of transactivation of the cyclin E gene in EFT cells. We found that EWS-Fli1 enhanced the activity of the cyclin E gene promoter partially through E2F binding sites in the promoter. In addition, the basic transcriptional factor, Sp1, might also be involved in the transactivation of the cyclin E gene by EWS-Fli1. To study the biological significance of cyclin E overexpression in EFT cells, we used flavopiridol, a pan-cyclin-dependent kinase (CDK) inhibitor and found that flavopiridol efficiently suppressed the growth of EFT cells in vitro and in vivo by the inhibition of cyclinE/CDK2 kinase activity and the induction of apoptosis. These results suggest that targeting of the cyclin/CDK complex may provide new insight into treatment of EFTs.

The prognostic and therapeutic relevance of p27kip1 in Ewing's family tumors

PURPOSE

Ewing's family tumors (EFTs) display the characteristic fusion gene EWS-Fli1. We have reported EWS-Fli1 may promote the cell cycle progression accompanied by the suppression of the expression of cyclin-dependent kinase inhibitor p27(kip1) in EFT cells. Here, we describe the prognostic and therapeutic relevance of p27 in EFTs.

EXPERIMENTAL DESIGN

We examined tumor samples taken from 21 patients with primary EFTs for the expression of p27 protein immunohistochemically and evaluated its correlation with clinical outcome. We also investigated the usefulness of p27 as a therapeutic strategy in vitro and in vivo using p27 expression adenovirus. Finally, we examined the process of EWS-Fli1-mediated reduction of p27 expression.

RESULTS

Immunohistochemical analysis showed that a low expression level of p27 protein was related to poor event-free survival in an univariate analysis and that the expression level of p27 correlated more significantly with patient survival than several clinical factors in a multivariate survival analysis. Overexpression of p27 with the adenoviral vector remarkably inhibited the cell growth in all EFT cells tested and further induced apoptosis in the wild-type p53 EFT cells. In vivo studies demonstrated a reduction in tumor growth of EFT xenograft in nude mice treated with the intratumoral injection of p27-expressing adenovirus. EWS-Fli1 did not significantly affect the p27 promoter activity and p27 mRNA levels. However, the challenge of the proteasome inhibitor caused accumulation of p27 protein in EFT cells. These data strongly suggest EWS-Fli1 might attenuate p27 protein level via activation of the proteasome-mediated degradation pathway.

CONCLUSIONS

Our findings provide the first evidence of the prognostic relevance of p27 expression in EFTs. We propose p27 as a novel and powerful therapeutic factor for the molecular target therapy of EFTs.

Modulation of activator protein 1/DNA binding activity by acoustic overstimulation in the guinea-pig cochlea

Changes in gene expression are part of the homeostatic machinery with which cells respond to external stimuli or assaults. The activity of the early response transcriptional factor activator protein-1 (AP-1) can be modulated by a variety of environmental stimuli including those that alter the cellular oxidation/reduction status. This study investigates the activation of AP-1/DNA binding in the guinea-pig cochlea in response to acoustic overstimulation which produces reactive oxygen species. Electrophoretic mobility shift assays revealed that binding of AP-1 to its radiolabeled oligonucleotide probe markedly changed in nuclear extracts of inner ear tissues following intense noise exposure (4 kHz octave band, 115 dB, 5 h). AP-1/DNA binding increased in the organ of Corti and the lateral wall tissues immediately after the exposure, returning to near-baseline levels 5 h later. At 15 h after noise, a second peak of binding activity occurred in the organ of Corti whereas stria vascularis showed a lesser but more sustained activity. Binding in nuclear extracts from the spiral ganglion did not change. Incubation of nuclear extracts with antibodies against Fos/Jun family proteins prior to a supershift assay showed Fra-2 as a major component of the AP-1 complex immediately after the noise exposure. In the organ of Corti, Fra-2 immunoreactivity was localized to the middle turn, i.e. the region which is most affected by the 4-kHz octave band exposure. The results suggest the modulation of gene expression via the activation of AP-1 as a consequence of noise trauma but also demonstrate differential responses in cochlear tissues.

Identification of p21WAF1/CIP1 as a direct target of EWS-Fli1 oncogenic fusion protein

Translocation t(11;22) is a karyotypic abnormality detected in over 90% of Ewing's family tumors. This translocation results in the EWS-Fli1 fusion gene, which has been shown to be a potent, single-step transforming gene. We reported previously that suppression of the EWS-Fli1 fusion protein altered the expression of G(1) regulatory cyclins and cyclin-dependent kinase inhibitors both at mRNA and protein levels, resulting in G(1) growth arrest in Ewing's family tumor cell lines. These data suggest that the G(1) regulatory molecules may be targets of the EWS-Fli1 fusion protein, which functions as an aberrant transcription factor. By using electrophoretic mobility shift assays, we show here the direct association of EWS-Fli1 fusion protein with ETS consensus sequences, which are in the promoter of the p21(WAF1/CIP1) gene. Reporter gene assays revealed that the activity of the p21(WAF1/CIP1) promoter is negatively regulated by EWS-Fli1 fusion protein through at least two ETS-binding sites in the promoter. EWS-Fli1 interacted with p300 cotransactivator and suppressed its histone acetyltransferase activity, which may explain the down-regulation of p21(WAF1/CIP1) by EWS-Fli1. In the presence of a histone deacetylase inhibitor, the histone acetyltransferase activity of the Ewing's family tumor cell was recovered resulting in the induction of p21, and the cell growth was dramatically inhibited. These results demonstrated that p21(WAF1/CIP1) might be one of the direct targets of EWS-Fli1, and that p21(WAF1/CIP1) could serve as a target for a molecularly based therapy for Ewing's family tumors.

High-dose chemotherapy and autologous peripheral blood stem-cell transfusion after conventional chemotherapy for patients with high-risk Ewing's tumors

Although the overall results of treatment of Ewing's tumors have improved, patients with high-risk factors, including metastatic disease at diagnosis, bulky primary tumors, axial sites, and age >15 years, continue to have poor prognoses. The effects of high-dose chemotherapy and autologous peripheral blood stem-cell transplantation on high-risk Ewing's tumor patients have been reported. In most of these studies, conditioning and high-dose regimens varied among patients. Here we report the feasibility and effects of a high-dose chemotherapy regimen conducted in our institution. Seven patients with high-risk Ewing's tumors were treated by high-dose chemotherapy. The patients received four cycles of remission induction chemotherapy, and then peripheral blood stem cells were mobilized by high-dose etoposide and harvested. Myeloablative chemotherapy consisted of carboplatin, ifosfamide, and etoposide. The patients have 5-year overall and relapse-free survival probabilities of 0.86 and 0.81, respectively. The results were significantly better than those for patients treated with conventional chemotherapy alone. None of the patients had severe side effects. The high-dose regimen and transplantation were feasible and well tolerated. The poor prognoses of high-risk Ewing's tumor patients may be improved by high-dose chemotherapy with peripheral blood stem cell transplantation. However, the real impact of the therapy on the clinical outcome of patients with high-risk Ewing's tumors should be evaluated in a prospective, randomized study.

Downregulation and forced expression of EWS-Fli1 fusion gene results in changes in the expression of G(1)regulatory genes

Chromosomal translocation t(11;22)(q24:q12) is detected in approximately 90% of tumours of the Ewing family (ET). This translocation results in EWS-Fli1 gene fusion which produces a EWS-Fli1 fusion protein acting as an aberrant transcriptional activator. We previously reported that the inhibition of EWS-Fli1 expression caused the G(0)/G(1)arrest of ET cells. We, therefore, hypothesized that EWS-Fli1 may affect the expression of G(1)regulatory genes. Downregulation of EWS-Fli1 fusion proteins was observed 48 hours after the treatment with EWS-Fli1 antisense oligonucleotides. The expressions of G(1)cyclins, cyclin D1 and cyclin E, were markedly decreased in parallel with the reduction of EWS-Fli1 fusion protein. On the other hand, the expression of p21 and p27, which are important cyclin-dependent kinase inhibitors (CKIs) for G(1)--S transition, was dramatically increased after the treatment with EWS-Fli1 antisense oligonucleotides. RT-PCR analysis showed that alteration of the expressions of the cyclins and CKIs occurred at the mRNA level. Furthermore, transfection of EWS-Fli1 cDNA to NIH3T3 caused transformation of the cells and induction of the expression of cyclin D1 and E. Clinical samples of ET also showed a high level of expression of cyclin D1 mRNA, whereas mRNAs for p21 and p27 were not detected in the samples. These findings strongly suggest that the G(1)--S regulatory genes may be involved in downstream of EWS-Fli1 transcription factor, and that the unbalanced expression of G(1)--S regulatory factors caused by EWS-Fli1 may lead to the tumorigenesis of ET.

Acetylcholine-evoked calcium increases in Deiters' cells of the guinea pig cochlea suggest alpha9-like receptors

The medial efferent system innervates outer hair cells in the organ of Corti. Neurotransmission at this synapse is mediated by acetylcholine (ACh) acting on nicotinic ACh receptors containing the alpha9 subunit. In addition to the sensory cells, the supporting cells of the mammalian cochlea also receive efferent innervation but the neurotransmitter(s) at these synapses are not known. We show slow transient increases of intracellular calcium evoked by ACh in isolated Deiters' cells of the guinea pig cochlea. The antagonists atropine, d-tubocurarine and strychnine blocked the ACh-effect. Nicotine was an ineffective agonist. The pharmacologic profile and the kinetics of the calcium response suggest an alpha9-like ACh receptor on Deiters' cells similar but not identical to that on the outer hair cells.

Nitric oxide/cyclic GMP pathway attenuates ATP-evoked intracellular calcium increase in supporting cells of the guinea pig cochlea

We demonstrate here that nitric oxide (NO) attenuates ATP-evoked calcium transients in Deiters' and Hensen's cells, "supporting" (nonsensory) cells of the guinea pig cochlea, by means of activation of soluble guanylyl cyclase and protein kinase G. The enzymatic activities associated with the nitric oxide/cGMP/protein kinase G pathway had previously been demonstrated to be present in Deiters' and Hensen's cells. We now isolate these cells and measure changes in intracellular free calcium by using the calcium indicator fluo-3. In Deiters' cells, calcium increased rapidly in response to the application of ATP. The increase was attenuated when the pathway was stimulated by NO donors (diethylamine NONOate or sodium nitroprusside) or the cyclic GMP analog, 8-bromo-cyclic GMP. When the activation of the pathway was blocked by the additional presence of inhibitors of soluble guanylyl cyclase (LY83583) or protein kinase G (Rp-8-bromo-cyclic GMP or KT5823), the response to ATP was restored. The reactions also occurred in calcium-free media. Hensen's cells responded similarly. These results provide evidence that intracellular calcium is regulated by the NO/cGMP/protein kinase G pathway in the inner ear.