Gait analysis of a patient after femoral nerve and malignant soft tissue tumor resections: a case report.

BACKGROUND: Malignant femoral soft tissue tumors are occasionally resected together with the femoral nerves, but this can cause loss of knee extensor muscle activity. To the best of our knowledge, no previous reports have detailed the gait analysis of such cases in combination with electromyography. Herein, we report the gait analysis of a patient who underwent left groin synovial sarcoma and left femoral nerve resection 12 years ago. CASE PRESENTATION: We analyzed the gait of a 38-year-old man who was able to walk unaided after the resection of a synovial sarcoma in the left groin together with the ipsilateral femoral nerve. The muscle activities of the affected medial (MH) and lateral hamstrings (LH), and lateral heads of the gastrocnemius (GL) were increased during 50-75% of the stance phase. The hip flexion angle of the affected limb was smaller, and the ankle plantar flexion angle of the affected limb was larger than that of the non-affected limb. This means that in the affected limb, the hip and ankle angles were adjusted to prevent knee collapse, and the MH, LH, and GL muscles contributed in the mid- and late-stance phases. Moreover, we found that the hamstring and gastrocnemius of the affected limb worked together to keep the ipsilateral knee extended in the mid-stance phase and slightly flexed in the late-stance phase. CONCLUSIONS: Patients capable of walking after femoral nerve resection may control their hamstrings and gastrocnemius muscles collaboratively to prevent ipsilateral knee collapse in the mid- and late-stance phases.

MicroRNA-329-3p inhibits the Wnt/ß-catenin pathway and proliferation of osteosarcoma cells by targeting transcription factor 7-like 1.

An important factor in the emergence and progression of osteosarcoma (OS) is the dysregulated expression of microRNAs (miRNAs). Transcription factor 7-like 1 (TCF7L1), a member of the T cell factor/lymphoid enhancer factor (TCF/LEF) transcription factor family, interacts with the Wnt signaling pathway regulator ß-catenin and acts as a DNA-specific binding protein. This study sought to elucidate the impact of the interaction between miR-329-3p and TCF7L1 on the growth and apoptosis of OS and analyze the regulatory expression relationship between miRNA and mRNA in osteosarcoma cells using a variety of approaches. MiR329-3p was significantly downregulated, while TCF7L1 was considerably up-regulated in all examined OS cell lines. Additionally, a clinical comparison study was performed using the TCGA database. Subsequently, the regulatory relationship between miR-329-3p and TCF7L1 on the proliferation and apoptosis of OS cells was verified through in vitro and in vivo experiments. When miR-329-3p was transfected into the OS cell line, the expression of TCF7L1 decreased, the proliferation of OS cells was inhibited, the cytoskeleton disintegrated, and the nucleus condensed to form apoptotic bodies. The expression of proteins that indicate apoptosis increased simultaneously. The cell cycle was arrested in the G0/G1 phase, and the G1/S transition was blocked. The introduction of miR-329-3p also inhibited downstream Cyclin D1 of the Wnt pathway. Xenograft experiments indicated that the overexpression of miR-329-3p significantly inhibited the growth of OS xenografts in nude mice, and the expression of TCF7L1 and c-Myc in tumor tissues decreased. MiR-329-3p was significantly reduced in OS cells and played a suppressive role in tumorigenesis and proliferation by targeting TCF7L1 both in vitro and in vivo. Osteosarcoma cell cycle arrest and pathway inhibition were observed upon the regulation of TCF7L1 by miR-329-3p. Summarizing these results, it can be inferred that miR-329-3p exerts anticancer effects in osteosarcoma by inhibiting TCF7L1.

Sequential treatments with TRK inhibitors in a patient with NTRK fusion-positive sarcoma: A case report.

RATIONALE: Precision medicine and tumor-agnostic treatment strategies have recently been promoted for clinical use. One of the most successful treatments in patients with neurotrophic tyrosine receptor kinase (NTRK) fusion-positive tumors is targeting the tropomyosin receptor kinase (TRK) with an inhibitor. The TRK inhibitors, larotrectinib, and entrectinib, have been approved in many countries. Nevertheless, the most effective administration regimen for these TRK inhibitors is uncertain. To date, no reports have shown the efficacy of sequential treatment with larotrectinib and entrectinib in patients with NTRK fusion-positive tumors. In this report, we present a patient with NTRK fusion-positive sarcoma arising from the anterior mediastinum, with tumor progression after 4 months of entrectinib use. The patient took larotrectinib subsequently and maintained disease control for more than 21 months. PATIENT CONCERNS: A 48-year-old female visited a physician because she experienced difficulty in breathing and chest and back pain with no obvious cause 2 months ago. Computed tomography (CT)-guided biopsy was performed at a district general hospital, and histopathological examination revealed a small round cell tumor. She was referred to our hospital, and a second CT-guided biopsy was performed to confirm the pathological diagnosis. Considering the results of the histopathological examination, Ewing sarcoma was suspected, but a specific fusion gene was not detected due to poor quality specimens. DIAGNOSES: After 3 regimens of cytotoxic chemotherapy, biopsy was repeated, and specimens were analyzed using next-generation sequencing. The PHF20-NTRK1 fusion gene was detected, and the tumor was finally diagnosed as an NTRK fusion-positive sarcoma. INTERVENTIONS: She was administered the TRK inhibitor entrectinib, but the tumor started to grow after 4 months of medication, and she stopped taking entrectinib. After 1 cycle of cytotoxic chemotherapy, another TRK inhibitor, larotrectinib, was administered. OUTCOMES: Her stable disease was maintained for more than 21 months. Here, we have shown that sequential administration of both drugs can be effective. LESSONS: In the treatment of NTRK fusion-positive tumors, there are cases in which 2 approved first-generation TRK inhibitors can be used sequentially.

Tumor-suppressive microRNA-152 inhibits the proliferation of Ewing's sarcoma cells by targeting CDK5R1.

We elucidated the mechanism through which the reduced expression of miR-152 leads to the overexpression of its target cyclin-dependent kinase-5 activator 1 (CDK5R1) in Ewing's sarcoma (ES) cells and the role of this mechanism in the proliferation of ES cells. To explore possible oncogenic factors in ES, we conducted microarray-based investigation and profiled the changes in miRNA expression and their effects on downstream mRNAs in five ES cell lines and human mesenchymal stem cells (hMSCs). miR-152 was significantly downregulated, while cyclin-dependent kinase-5 activator 1 (CDK5R1) expression was significantly upregulated in all tested ES cells as compared to hMSCs. The overexpression of CDK5R1 led to the activation of CDK5, enabling the phosphorylation of retinoblastoma protein and persistent overexpression of CCNE. Moreover, miR-152 suppressed cell proliferation via cell cycle retardation, and its upregulation reduced tumor size and CCNE expression in tumor tissues. The overexpression of cyclin E (CCNE) has been detected in ES cells, but the detailed mechanisms have not been previously elucidated. These findings identify the miR152-CDK5R1 signaling axis as a critical mechanism for tumorigenesis that may serve as a new therapeutic target in Ewing's sarcoma. We believe that our results will aid in the development of effective treatment strategies for patients with ES.

Efficacy of gelatin-thrombin matrix sealants for blood loss in single-level transforaminal lumbar interbody fusion.

Although gelatin-thrombin matrix sealants have been used successfully in other surgery types, their effect on reducing blood loss during single-level transforaminal lumbar interbody fusion is unclear. We thus examined the efficacy of gelatin-thrombin matrix sealants for reducing blood loss during such surgery. We analyzed 102 patients who underwent single-level transforaminal lumbar interbody fusion for lumbar degenerative disease. We compared body mass index, surgical time, intraoperative blood loss, postoperative blood loss, true total blood loss, hidden blood loss, the proportion of blood transfusion, blood pressure pre- and post-surgery (systolic and diastolic), and pre-and post-surgery laboratory data (hemoglobin, hematocrit, platelets, prothrombin time, activated partial thromboplastin time, and D-dimer) between patients in whom gelatin-thrombin matrix sealants were (GTMS group) or were not (control group) used during surgery. One-week postoperative epidural hematoma size was measured using magnetic resonance imaging. The GTMS and control groups included 54 (24 males and 30 females) and 48 patients (19 males and 29 females). Intraoperative, true total, and hidden blood loss; epidural hematoma size; and hospitalization duration were significantly lower in the GTMS than in the control group. Intraoperative blood loss correlated with surgical time (R = 0.523, P = .001), body mass index (R = 0.221, P = .036), and the amount of gelatin-thrombin matrix sealant used (r = -0.313, P = .002). In multivariate linear regression analysis using intraoperative blood loss as the dependent variable, surgical time (standardization coefficient 0.516, P = .001) and amount of gelatin-thrombin matrix sealant used (standardization coefficient -0.220, P = .032) were independently related factors. In our study, the GTMS group had significantly less intraoperative true total and hidden blood loss than did the control group. Thus, use of gelatin-thrombin matrix sealants reduce perioperative blood loss in transforaminal lumbar interbody fusion.

The anti-oncogenic effect of 17-DMAG via the inactivation of HSP90 and MET pathway in osteosarcoma cells.

Heat shock protein (HSP) 90 plays a crucial role in correcting the misfolded three-dimensional structure of proteins, assisting them in folding into proper conformations. HSP90 is critical in maintaining the normal functions of various proteins within cells, as essential factors for cellular homeostasis. Contrastingly, HSP90 simultaneously supports the maturation of cancer-related proteins, including mesenchymal epithelial transition factor (MET) within tumor cells. All osteosarcoma cell lines had elevated MET expression in the cDNA array in our possession. MET, a tyrosine kinase receptor, promotes proliferation and an anti-apoptotic state through the activation of the MET pathway constructed by HSP90. In this study, we treated osteosarcoma cells with an HSP90 inhibitor, 17-demethoxygeldanamycin hydrochloride (17-DMAG), and assessed the changes in the MET signaling pathway and also the antitumor effect of the drug. The cell cycle in osteosarcoma cells administered 17-DMAG was found to be halted at the G2/M phase. Additionally, treatment with 17-DMAG inhibited cell proliferation and induced apoptosis. Inhibition of tumor cell proliferation was also observed in an in vivo model system, mice that were treated with 17-DMAG. Based on the results of this study, we were able to confirm that 17-DMAG promotes inhibition of osteosarcoma cell proliferation and induction of apoptosis by inhibition of MET, a protein highly expressed in osteosarcoma cells. This approach may be useful for the establishment of a new treatment strategy for patients resistant to the standard treatment for osteosarcoma.

Protocol for the 2ND-STEP study, Japan Clinical Oncology Group study JCOG1802: a randomized phase II trial of second-line treatment for advanced soft tissue sarcoma comparing trabectedin, eribulin and pazopanib.

BACKGROUND: Soft tissue sarcomas (STS) are a rare type of malignancy comprising a variety of histological diagnoses. Chemotherapy constitutes the standard treatment for advanced STS. Doxorubicin-based regimens, which include the administration of doxorubicin alone or in combination with ifosfamide or dacarbazine, are widely accepted as first-line chemotherapy for advanced STS. Trabectedin, eribulin, pazopanib, and gemcitabine plus docetaxel (GD), which is the empirical standard therapy in Japan, are major candidates for second-line chemotherapy for advanced STS, although clear evidence of the superiority of any one regimen is lacking. The Bone and Soft Tissue Tumor Study Group of the Japan Clinical Oncology Group (JCOG) conducts this trial to select the most promising regimen among trabectedin, eribulin, and pazopanib for comparison with GD as the test arm regimen in a future phase III trial of second-line treatment for patients with advanced STS. METHODS: The JCOG1802 study is a multicenter, selection design, randomized phase II trial comparing trabectedin (1.2 mg/m2 intravenously, every 3 weeks), eribulin (1.4 mg/m2 intravenously, days 1 and 8, every 3 weeks), and pazopanib (800 mg orally, every day) in patients with unresectable or metastatic STS refractory to doxorubicin-based first-line chemotherapy. The principal eligibility criteria are patients aged 16 years or above; unresectable and/or metastatic STS; exacerbation within 6 months prior to registration; histopathological diagnosis of STS other than Ewing sarcoma, embryonal/alveolar rhabdomyosarcoma, well-differentiated liposarcoma and myxoid liposarcoma; prior doxorubicin-based chemotherapy for STS, and Eastern Cooperative Oncology Group performance status 0 to 2. The primary endpoint is progression-free survival, and the secondary endpoints include overall survival, disease-control rate, response rate, and adverse events. The total planned sample size to correctly select the most promising regimen with a probability of > 80% is 120. Thirty-seven institutions in Japan will participate at the start of this trial. DISCUSSION: This is the first randomized trial to evaluate trabectedin, eribulin, and pazopanib as second-line therapies for advanced STS. We endeavor to perform a subsequent phase III trial comparing the best regimen selected by this study (JCOG1802) with GD. TRIAL REGISTRATION: This study was registered with the Japan Registry of Clinical Trials ( jRCTs031190152 ) on December 5, 2019.

Surrogacy analysis of intermediate end-points for overall survival in randomized controlled trials of rhabdomyosarcoma.

Treatment of malignant tumors, such as rhabdomyosarcoma (RMS), can improve overall survival (OS). It is time-consuming and expensive for patients to obtain benefits from randomized controlled trials (RCTs) with OS as the primary end-point. Therefore, another surrogate end-point is necessary; however, there is no report on the surrogacy analysis of RMS. In this study, we performed a systematic review of RCTs, involving patients with newly diagnosed RMS, and 11 RCTs were identified. We performed a meta-analysis to assess the surrogacy of intermediate end-points for OS. The correlations between surrogate end-points and OS were investigated using Spearman's rank correlation coefficient (ρ). The coefficient of determination (R2) was employed to measure the strength of the association. A total of 5183 patients were randomly allocated to 34 treatment groups. A marginal correlation (R2 = 0.281, ρ = 0.445) between the hazard ratios (HRs) for event-free survival (EFS) and OS was observed. In patients with localized RMS, the EFS HR had a weaker correlation with OS HR in the sensitivity analysis than that in the primary analysis. Overall, the surrogacy of EFS for OS cannot be confirmed.

Mechanism of action of non-camptothecin inhibitor Genz-644282 in topoisomerase I inhibition.

Topoisomerase I (TOP1) controls the topological state of DNA during DNA replication, and its dysfunction due to treatment with an inhibitor, such as camptothecin (CPT), causes replication arrest and cell death. Although CPT has excellent cytotoxicity, it has the disadvantage of instability under physiological conditions. Therefore, new types of TOP1 inhibitor have attracted particular attention. Here, we characterised the effect of a non-camptothecin inhibitor, Genz-644282 (Genz). First, we found that treatment with Genz showed cytotoxicity by introducing double-strand breaks (DSBs), which was suppressed by co-treatment with aphidicolin. Genz-induced DSB formation required the functions of TOP1. Next, we explored the advantages of Genz over CPT and found it was effective against CPT-resistant TOP1 carrying either N722S or N722A mutation. The effect of Genz was also confirmed at the cellular level using a CPT-resistant cell line carrying N722S mutation in the TOP1 gene. Moreover, we found arginine residue 364 plays a crucial role for the binding of Genz. Because tyrosine residue 723 is the active centre for DNA cleavage and re-ligation by TOP1, asparagine residue 722 plays crucial roles in the accessibility of the drug. Here, we discuss the mechanism of action of Genz on TOP1 inhibition.

Activation of recombinational repair in Ewing sarcoma cells carrying EWS-FLI1 fusion gene by chromosome translocation.

Chromosome translocation (TL) is an important mode of genomic changes underlying human tumorigenesis, the detailed mechanisms of which are, however, still not well understood. The two major modalities of DNA double strand break repair, i.e. homologous recombination (HR) and non-homologous end-joining (NHEJ), have been hypothesized. In a typical TL+ human neoplasm, Ewing sarcoma, which is frequently associated with t(11;22) TL encoding the EWS-FLI1 fusion gene, NHEJ has been regarded as a model to explain the disease-specific TL. Using comprehensive microarray approaches, we observed that expression of the HR genes, particularly of RAD51, is upregulated in TL+ Ewing sarcoma cell lines, WE-68 and SK-N-MC, as in the other TL+ tumor cell lines and one defective in DNA mismatch repair (MMR). The upregulated RAD51 expression indeed lead to frequent focus formation, which may suggest an activation of the HR pathway in these cells. Furthermore, sister chromatid exchange was frequently observed in the TL+ and MMR-defective cells. Intriguingly, ionizing irradiation revealed that the decrease of 53BP1 foci was significantly retarded in the Ewing sarcoma cell lines, suggesting that the NHEJ pathway may be less active in the cells. These observations may support an HR involvement, at least in part, to explain TL in Ewing sarcoma.

Perioperative Adriamycin plus ifosfamide vs. gemcitabine plus docetaxel for high-risk soft tissue sarcomas: randomised, phase II/III study JCOG1306.

BACKGROUND: This randomised phase II/III trial aimed to determine whether perioperative chemotherapy with gemcitabine plus docetaxel (GD) is non-inferior to the standard Adriamycin plus ifosfamide (AI) in terms of overall survival (OS) in patients with soft tissue sarcoma (STS). METHODS: Patients with localised high-risk STS in the extremities or trunk were randomised to receive AI or GD. The treatments were repeated for three preoperative and two postoperative courses. The primary endpoint was OS. RESULTS: Among 143 enrolled patients who received AI (70 patients) compared to GD (73 patients), the estimated 3-year OS was 91.4% for AI and 79.2% for GD (hazard ratio 2.55, 95% confidence interval: 0.80-8.14, P = 0.78), exceeding the prespecified non-inferiority margin in the second interim analysis. The estimated 3-year progression-free survival was 79.1% for AI and 59.1% for GD. The most common Grade 3-4 adverse events in the preoperative period were neutropenia (88.4%), anaemia (49.3%), and febrile neutropenia (36.2%) for AI and neutropenia (79.5%) and febrile neutropenia (17.8%) for GD. CONCLUSIONS: Although GD had relatively mild toxicity, the regimen-as administered in this study-should not be considered a standard treatment of perioperative chemotherapy for high-risk STS in the extremities and trunk. CLINICAL TRIAL REGISTRATION: jRCTs031180003.

Patellar dislocation following distal femoral replacement after extra-articular knee resection for bone sarcoma: A case report.

BACKGROUND: For the treatment of bone sarcoma in the distal femur, wide-margin resection and knee reconstruction with tumor endoprosthesis are standard therapies. Extra-articular knee resection is required in cases of tumor invasion of the knee joint; however, the incidence of complications, such as aseptic loosening, prosthesis infection, and implant failure, is higher than that following intra-articular knee resection. To the best of our knowledge, there are three reports of patellar dislocations after replacement of a tumor endoprosthesis. CASE SUMMARY: A 36-year-old man with no significant past medical history was admitted to our institution with continuous pain in his left knee for 4 mo. An open biopsy was performed, and the patient was diagnosed with a left distal femoral malignant bone tumor. Extra-articular knee resection and knee reconstruction with a tumor endoprosthesis were performed. Although the alignment of the tumor prosthesis was acceptable, knee instability was noticed postoperatively. The axial radiographic view of the patellar and computed tomography showed lateral patellar dislocation at 4 wk postoperatively. The patient had to undergo a lateral release and proximal realignment. He could perform his daily activities at 9 mo postoperatively. Radiography revealed no patellar re-dislocation. CONCLUSION: Proximal realignment may be considered during primary surgery if there is an imbalance in the forces controlling the patellar tracking.

A randomized phase III trial of denosumab before curettage for giant cell tumor of bone. JCOG1610.

OBJECTIVES: The aim of JCOG1610 (randomized controlled phase III trial) was to confirm the superiority of preoperative denosumab to curettage with adjuvant local therapy for patients with giant cell tumor of bone without possible post-operative large bone defect. METHODS: The primary endpoint was relapse-free survival and the total sample size was set at 106 patients. Patient accrual began in October 2017. However, the accrual was terminated in December 2020 due to a recommendation from the Data and Safety Monitoring Committee because of poor patient accrual. Now, we report the descriptive results obtained in this study. RESULTS: A total of 18 patients had been registered from 13 Japanese institutions at the time of termination on December 2020. Eleven patients were assigned to Arm A (curettage and adjuvant local therapy) and 7 to Arm B (preoperative denosumab, curettage and adjuvant local therapy). Median follow-up period was 1.6 (range: 0.5-2.8) years. Protocol treatment was completed in all but one patient in Arm A who had a pathological fracture before surgery. All patients in Arm B were treated with five courses of preoperative denosumab. Relapse-free survival proportions in Arm A and B were 90.0% (95% confidence interval: 47.3-98.5) and 100% (100-100) at 1 year, and 60.0% (19.0-85.5) and 62.5% (14.2-89.3) at 2 years, respectively [hazard ratio (95% confidence interval): 1.51 (0.24-9.41)]. CONCLUSION: In terms of relapse-free survival, the superiority of preoperative denosumab was not observed in patients with giant cell tumor of bone without possible post-operative large bone defect.

Analysis of the signal cross talk via CCL26 in the tumor microenvironment in osteosarcoma.

Interaction with surrounding healthy cells plays a major role in the growth and metastasis of osteosarcoma. In this study, we hypothesized that humoral factors, which do not require direct contact with cells, are involved in the interaction between osteosarcoma and the surrounding cells. We identified the humoral factor involved in the association between tumor cells and surrounding normal cells using a co-culture model and investigated the significance of our findings. When human osteosarcoma cells (MG63) and human mesenchymal stem cells (hMSCs) were co-cultured and comprehensively analyzed for changes in each culture group, we found that the expression of chemokine (CC motif) ligand 26 (CCL26) was significantly enhanced. We also analyzed the changes in cell proliferation in co-culture, enhanced interaction with administration of recombinant CCL26 (rCCL26), reduced interaction with administration of anti-CCL26 antibodies, changes in invasive and metastatic abilities. CCL26 levels, motility, and invasive capability increased in the co-culture group and the group with added rCCL26, compared to the corresponding values in the MG63 single culture group. In the group with added CCL26 neutralizing antibodies, CCL26 level decreased in both the single and co-culture groups, and motility and invasive ability were also reduced. In a nude mice lung metastasis model, the number of lung metastases increased in the co-culture group and the group with added rCCL26, whereas the number of tumors were suppressed in the group with added neutralizing antibodies compared to those in the MG63 alone. This study identified a possible mechanism by which osteosarcoma cells altered the properties of normal cells to favorably change the microenvironment proximal to tumors and to promote distant metastasis.

Sensitive quantification of free pazopanib using ultra-high performance liquid chromatography coupled to tandem mass spectrometry and assessment of clinical application.

Pazopanib is widely used to treat renal cell carcinomas and soft tissue tumors in Japan. Although several reports demonstrated the usefulness of therapeutic drug monitoring (TDM) of pazopanib, those studies measured only total pazopanib concentration. For drugs with high protein binding rates such as pazopanib, measuring free concentrations may be clinically more useful than measuring total concentrations. In this study, we aimed to develop a high-throughput method for quantification of free pazopanib in human plasma using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Free pazopanib was separated by ultrafiltration. After a simple solid-phase extraction step using a 96-well plate, pazopanib was analyzed by UHPLC-MS/MS in positive electrospray ionization mode. The novel method fulfilled the requirements of the US Food and Drug Administration guidelines for assay validation, and the lower limit of quantification was 0.05 ng/mL. The calibration curve was linear over the concentration range of 0.05-50 ng/mL. The average recovery rate was 66.9 ± 2.1% (mean ± SD). The precision was below 7.02%, and accuracy was within 10.60% across all quality control levels. Matrix effect varied between 44.4% and 60.4%. This assay was successfully applied to measure trough free pazopanib concentrations in three patients treated with pazopanib for soft tissue tumors. We succeeded to develop a novel high-throughput UHPLC-MS/MS method for quantification of free pazopanib in human plasma. This method can be applied to TDM for patients receiving pazopanib in the clinical setting.

The benzylisoquinoline alkaloids, berberine and coptisine, act against camptothecin-resistant topoisomerase I mutants.

DNA replication inhibitors are utilized extensively in studies of molecular biology and as chemotherapy agents in clinical settings. The inhibition of DNA replication often triggers double-stranded DNA breaks (DSBs) at stalled DNA replication sites, resulting in cytotoxicity. In East Asia, some traditional medicines are administered as anticancer drugs, although the mechanisms underlying their pharmacological effects are not entirely understood. In this study, we screened Japanese herbal medicines and identified two benzylisoquinoline alkaloids (BIAs), berberine and coptisine. These alkaloids mildly induced DSBs, and this effect was dependent on the function of topoisomerase I (Topo I) and MUS81-EME1 structure-specific endonuclease. Biochemical analysis revealed that the action of BIAs involves inhibiting the catalytic activity of Topo I rather than inducing the accumulation of the Topo I-DNA complex, which is different from the action of camptothecin (CPT). Furthermore, the results showed that BIAs can act as inhibitors of Topo I, even against CPT-resistant mutants, and that the action of these BIAs was independent of CPT. These results suggest that using a combination of BIAs and CPT might increase their efficiency in eliminating cancer cells.

Gait analysis of a patient who underwent complete resection of the patella and quadriceps femoris for soft tissue sarcoma.

The knee extension mechanism including the quadriceps femoris muscles and patella plays a crucial role in the stance phase of a normal gait cycle. We performed gait analysis of a patient who had undergone complete resection of the knee extension mechanism. An 8-month-old boy developed infantile fibrosarcoma of the right knee and underwent resection of the quadriceps femoris muscles, patella, and patellar tendon. The gait analysis performed at 8 years of age demonstrated that he could maintain the knee joint extension position during the stance phase. Increased muscle activities in the hamstring and gastrocnemius were observed. The results suggest that the hamstring and gastrocnemius muscles might play a role in maintaining the knee extension position during the stance phase. We suggest the importance of reinforcing these muscles in rehabilitation for patients who lost the knee extension mechanism.

Primary clear cell sarcoma of the femur: a unique case with RT-PCR and direct sequencing confirmation of EWSR1/ATF1 fusion gene.

BACKGROUND: It is very rare for clear cell sarcomas (CCS) to arise in the bone. During diagnosis, it is important to distinguish primary CCS of bone from bone metastasis of melanoma because this difference fundamentally changes the therapeutic options. Recently, characteristic fusion genes of CCS have been detected using reverse transcription polymerase chain reaction (RT-PCR) or direct sequencing which allowed to distinguish CCS from melanoma. However, there was no study applying these analyses with positive results. In this case, we describe the use of fusion gene analysis to diagnose a primary CCS of the bone. CASE PRESENTATION: A 36-year-old male presented with a four-months history of left knee pain. Magnetic resonance imaging showed a lesion in the left femoral medial epicondyle. Histological examination of the biopsy specimen revealed proliferating oval or rounded cells. These cells had clear cytoplasm arranged in fascicles or compact nests with frequent deposits of brown pigment. Furthermore, immunohistochemistry analysis revealed that tumor cells were positive for S-100 protein, HMB-45, Melan-A, and SOX10. It stained negative for CD34 and BRAF v600e. Conclusively, detection of the EWSR1/ATF1 fusion gene using RT-PCR and direct sequencing confirmed that the lesion was a primary CCS of the bone. Wide-margin resection and reconstruction with a tumor endoprosthesis were performed. CONCLUSIONS: Herein, we diagnosed a rare case of primary CCS of the bone by detecting EWSR1/ATF1 fusion gene using RT-PCR and direct sequencing. Since fluorescence-in situ hybridization (FISH) and RT-PCR could show false positive by mainly due to technical problems, it is better to perform direct sequencing to confidently diagnose the tumor as a primary CCS especially at very rare site such as bone.

Development of a High-Throughput Quantification Method for Pazopanib Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry and Its Clinical Application in Patients With Soft Tissue Tumors.

BACKGROUND: Pazopanib is widely used to treat renal cell carcinomas and soft tissue tumors in Japan. Pazopanib has significant therapeutic efficacy but it is associated with frequent severe adverse effects. Therapeutic drug monitoring (TDM) may help to prevent adverse effects. A more convenient and rapid pazopanib assay is desirable for the application of TDM in clinical settings. In this study, the authors developed a high-throughput method for quantifying pazopanib in human plasma using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). METHODS: After a simple solid-phase extraction step using a 96-well plate, pazopanib was analyzed by UHPLC-MS/MS in the positive electrospray ionization mode. RESULTS: The novel method fulfilled the requirements of the US Food and Drug Administration and the European Medicines Agency guidelines for assay validation, and the lower limit of quantification was 0.5 mcg/mL. The calibration curves were linear over the concentration range of 0.5-100 mcg/mL. The average recovery rate was 102.0% ± 3.9% (mean ± SD). The precision was below 5.0%, and the accuracy was within 12.0% for all quality control levels. Matrix effect varied between 90.9% and 97.1%. This assay was successfully applied to TDM of pazopanib trough concentrations in 3 patients treated with the drug for soft tissue tumors. CONCLUSIONS: The authors succeeded in developing a novel high-throughput UHPLC-MS/MS method for quantifying pazopanib in human plasma. This method can be applied to TDM of patients receiving pazopanib in clinical settings.

Osteomyelitis of the Distal Phalanx of the Thumb due to Parvimonas micra and Fusobacterium nucleatum: A Case Report.

We herein report a case of osteomyelitis of the distal phalanx of the thumb of a 55-year-old man caused by Parvimonas micra and Fusobacterium nucleatum. Osteomyelitis often occurs in long bones and rarely occurs in the bones of the fingers. In addition, osteomyelitis of the finger frequently occurs after trauma or surgery, and blood-borne infection is very rare. P. micra and F. nucleatum, normal flora of the oral cavity, are very rare pathogenic bacteria of osteomyelitis except in periodontal disease, and there are no previous reports regarding the occurrence of osteomyelitis due to P. micra and F. nucleatum in the finger bones.