Nanofiber-induced hierarchically-porous magnesium phosphate bone cements accelerate bone regeneration by inhibiting Notch signaling.

Magnesium phosphate bone cements (MPC) have been recognized as a viable alternative for bone defect repair due to their high mechanical strength and biodegradability. However, their poor porosity and permeability limit osteogenic cell ingrowth and vascularization, which is critical for bone regeneration. In the current study, we constructed a novel hierarchically-porous magnesium phosphate bone cement by incorporating extracellular matrix (ECM)-mimicking electrospun silk fibroin (SF) nanofibers. The SF-embedded MPC (SM) exhibited a heterogeneous and hierarchical structure, which effectively facilitated the rapid infiltration of oxygen and nutrients as well as cell ingrowth. Besides, the SF fibers improved the mechanical properties of MPC and neutralized the highly alkaline environment caused by excess magnesium oxide. Bone marrow stem cells (BMSCs) adhered excellently on SM, as illustrated by formation of more pseudopodia. CCK8 assay showed that SM promoted early proliferation of BMSCs. Our study also verified that SM increased the expression of OPN, RUNX2 and BMP2, suggesting enhanced osteogenic differentiation of BMSCs. We screened for osteogenesis-related pathways, including FAK signaing, Wnt signaling and Notch signaling, and found that SM aided in the process of bone regeneration by suppressing the Notch signaling pathway, proved by the downregulation of NICD1, Hes1 and Hey2. In addition, using a bone defect model of rat calvaria, the study revealed that SM exhibited enhanced osteogenesis, bone ingrowth and vascularization compared with MPC alone. No adverse effect was found after implantation of SM in vivo. Overall, our novel SM exhibited promising prospects for the treatment of critical-sized bone defects.

Phase 1 clinical trial to assess safety and efficacy of NY-ESO-1-specific TCR T cells in HLA-A∗02:01 patients with advanced soft tissue sarcoma.

New York esophageal squamous cell carcinoma-1 (NY-ESO-1)-specific T cell receptor (TCR) T cell therapy is effective in tumors with NY-ESO-1 expression, but a safe and effective TCR-T cell therapeutic protocol remains to be improved. Here, we report a phase 1 investigational new drug clinical trial with TCR affinity-enhanced specific T cell therapy (TAEST16001) for targeting NY-ESO-1. Enrolled patients receive TAEST16001 cell infusion after dose-reduced lymphodepletion with cyclophosphamide (15 mg/kg/day × 3 days) combined with fludarabine (20 mg/m2/day × 3 days), and the TCR-T cells are maintained with low doses of interleukin-2 injection post-adoptive transfer. Analysis of 12 patients treated with the regimen demonstrates no treatment-related serious adverse events. The overall response rate is 41.7%. The median progression-free survival is 7.2 months, and the median duration of response is 13.1 months. The protocol of TAEST16001 cells delivers a safe and highly effective treatment for patients with advanced soft tissue sarcoma (ClinicalTrials.gov: NCT04318964).

Carboxymethyl chitosan-alginate enhances bone repair effects of magnesium phosphate bone cement by activating the FAK-Wnt pathway.

There is a continuing need for artificial bone substitutes for bone repair and reconstruction, Magnesium phosphate bone cement (MPC) has exceptional degradable properties and exhibits promising biocompatibility. However, its mechanical strength needs improved and its low osteo-inductive potential limits its therapeutic application in bone regeneration. We functionally modified MPC by using a polymeric carboxymethyl chitosan-sodium alginate (CMCS/SA) gel network. This had the advantages of: improved compressive strength, ease of handling, and an optimized interface for bioactive bone in-growth. The new composites with 2% CMCS/SA showed the most favorable physicochemical properties, including mechanical strength, wash-out resistance, setting time, injectable time and heat release. Biologically, the composite promoted the attachment and proliferation of osteoblast cells. It was also found to induce osteogenic differentiation in vitro, as verified by expression of osteogenic markers. In terms of molecular mechanisms, data showed that new bone cement activated the Wnt pathway through inhibition of the phosphorylation of ß-catenin, which is dependent on focal adhesion kinase. Through micro-computed tomography and histological analysis, we found that the MPC-CMCS/SA scaffolds, compared with MPC alone, showed increased bone regeneration in a rat calvarial defect model. Overall, our study suggested that the novel composite had potential to help repair critical bone defects in clinical practice.

Clinical features and therapeutic outcomes of alveolar soft part sarcoma in children: A single-center, retrospective study.

Background: Alveolar soft part sarcoma (ASPS) is a rare sarcoma that has been shown to be highly effective to antiangiogenic agents and immune checkpoint inhibitors, but most reported studies about ASPS were concentrated on adult population. In this study, we aimed to describe the clinical features and therapeutic outcomes of ASPS in children. Methods: We retrospectively reviewed the records of patients with ASPS in our institution since Jan 2015. All patients included in this study were pathologically confirmed ASPS and aged under 12 years at the time of initial diagnosis. Demographic characteristics, tumor sizes, primary tumor sites, metastasis, treatments used, therapeutic responses and survivals were evaluated. Results: We identified a total of 56 patients to be initially diagnosed as ASPS since Jan 2015. A predisposition of high occurrence in head and neck (32.1%) was observed (versus 41.1% in limbs and 21.4% in trunk). 26 (46.4%) patients developed metastasis at the time of diagnosis or during follow-up. Tumors in tongue, pharynx and larynx had the least likelihood to metastasize (7.7%, P<0.05). Observation was recommended for 15 stage IV patients with only pulmonary metastasis. 7 (46.7%) patients remained stable until last follow up. The 1-year PFS rate was 83.3% and median progression-free survival time (PFS) was 29.4 months. 15 patients with progressive disease received mono or combined therapy. 11 patients received PD-1 monotherapy. 2 patients achieved partial response and 5 stable disease. The overall response rate was 18.2%. The median PFS of this group was 22.0 months, and the 1-year PFS rate was 70.0%. 4 patients received a combination therapy of PD-1 inhibitors plus tyrosine kinase inhibitors. All of them remained stable. No disease-related death occurred during follow-up. Conclusions: ASPS exhibits a higher occurrence in head and neck in children. ASPS originating from glossopharyngeal region tends to have a lower metastasis rate. ASPS displays a more indolent growth pattern in children, which makes observation a preferable choice for children with sole pulmonary metastasis. Pediatric ASPS appears to be less effective to targeted therapy and immunotherapy than adults. The treatment of progressive ASPS in children remains challenging.

Efficacy of PD-1 inhibitors combined with pegylated liposomal doxorubicin and dacarbazine compared with liposomal doxorubicin and dacarbazine in advanced leiomyosarcoma patients: a retrospective, single-institutional cohort study.

Background: PD-1 inhibitor monotherapy is ineffective for metastatic leiomyosarcoma (LMS), but it remains unclear whether PD-1 inhibitors demonstrate any efficacy when combined with chemotherapy. This study retrospectively evaluated pegylated liposomal doxorubicin (PLD) and dacarbazine (DTIC) with/without PD-1 inhibitors for advanced/metastatic LMS patients treated in our single institution. Methods: The inclusion criteria were a confirmed histological diagnosis of LMS, treatment between January 2020 and March 2022, measurable disease (evaluated by CT or MRI), an Eastern Cooperative Oncology Group (ECOG) performance status ≤2, and age ≥18 years. The endpoints were progression-free survival (PFS), overall survival (OS), and overall response rate (ORR). Results: A total of 41 patients were included in this study, among whom 21 received PLD and DTIC alone while 20 received PLD and DTIC with PD-1 inhibitors. There were no differences of clinical characteristics between the two groups. Although the chemo plus PD-1 group had a better ORR (30% vs. 4.8%, P=0.04), there were no benefits in terms of disease control rate (DCR) (80% vs. 66.7%, P=0.29), PFS (8.8 months, 95% CI: 4.57-13.0 vs. 6.1 months, 95% CI: 3.03-9.14, P=0.54), and OS (not reached in both groups, P=0.84) when compared to chemo alone. Multiple treatment lines and previous use of tyrosine kinase inhibitors (TKIs) seemed to be negative factors for PFS in the univariate analysis, but failed to be significant in the multivariate analysis. Conclusions: This retrospective, single-institutional study showed that PD-1 inhibitors combined with standard PLD and DTIC chemotherapy failed to exert benefits on survival for LMS patients. Considering the small sample size and retrospective clinical research design, further explorations are needed to verify the conclusion.

Efficacy and safety of apatinib in patients with untreated or chemotherapy-refractory soft tissue sarcoma: a multicenter, phase 2 trial.

Background: Anti-angiogenic agents have been reported to exert promising clinical activity for advanced soft tissue sarcoma (STS). Apatinib, a vascular endothelial growth factor receptor-2 tyrosine kinase inhibitor, is effective and safe for various solid tumors, but its role in STS remains unclear. The aim of this study was to explore the efficacy and safety of apatinib in patients with untreated or chemotherapy-refractory STS. Methods: In this multicenter, single-arm, phase 2 trial, patients aged 18-70 years with untreated or chemotherapy-refractory STS were enrolled and received 500 mg apatinib per day. During treatment, patients were followed up with imaging every 8 weeks. The primary endpoint was the 6-month progression-free survival (PFS) rate. The secondary endpoints were objective response rate (ORR), overall survival (OS), and adverse events (AEs), which were graded following the National Cancer Institute common terminology criteria for AEs version 4.03. Results: From June 2017 to October 2018, 53 patients were enrolled, 51 of whom received at least one dose of apatinib. Of the 53 patients, 41 (77.4%) had chemotherapy-refractory disease. The median follow-up was 13.3 months. The 6- and 12-month PFS rates were 46.8% and 25.2%, respectively, with a median PFS of 5.6 months [95% confidence interval (CI): 3.8-9.2 months]. The median PFS was 5.5 months for chemotherapy-refractory patients, 9.1 months for untreated patients, 13.9 months for patients with alveolar soft part sarcoma (ASPS), and 3.7 months for patients with clear cell sarcoma (CCS). The 12- and 24-month OS rates were 58.6% and 44.9%, respectively, with a median OS of 20.0 months (95% CI: 9.2-31.1 months). The median OS was 10.7 months for chemotherapy-refractory patients and not estimated for untreated, ASPS, nor CCS patients. In 50 evaluable patients, the ORR was 18.0% and the disease control rate was 86.0%. These results were similar to those of the per-protocol set. The most common grade 3 or 4 AEs included hypertension [30 (58.8%) of 51 patients], leukopenia [12 (23.5%)], proteinuria [8 (15.69%)], and hematuria [8 (15.69%)]. One patient died of unknown cause. Conclusions: This study suggested that apatinib might be effective and tolerable in patients with untreated or chemotherapy-refractory STS (NCT03064243).

A novel TMTC2-NTRK3 fusion in undifferentiated high-grade pleomorphic sarcoma.

Undifferentiated high-grade pleomorphic sarcoma (UHPS) is a rare soft tissue sarcoma (STS) originated from mesenchyme. UHPS is mostly advanced, aggressive and has poor prognosis. Patients with UHPS tend to have a lower 5-year survival rate than patients with other types of STS. NTRK fusions are commonly found in rare histological tumor types. Among sarcomas, 90% of infantile fibrosarcomas have NTRK fusions. Many other types of sarcomas have also been studied for NTRK fusions. Targeted therapy with NTRK inhibitors, such as Larotrectinib and Entrectinib, leads to response in most patients with NTRK1/2/3 gene fusion-positive tumors. Herein, we present a 68-years old man with UHPS by pathological diagnosis. Next-generation sequencing (NGS) revealed a novel TMTC2-NTRK3 fusion, which was also detected by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). This report broadens the spectrum of NTRK fusions in UHPS and highlights a new target for treatment.

SNHG9/miR-214-5p/SOX4 feedback loop regulates osteosarcoma progression.

Osteosarcoma (OS) is a high-grade, aggressive bone sarcoma. LncRNAs play a key regulatory role in controlling biological and pathological processes. The expression of lncRNA SNHG9 varies among different cancer tissues, and the role of SNHG9 in OS progression is unclear. In this study, we found SNHG9 overexpression in OS tissues and cells. In addition, downregulated SNHG9 expression impaired the proliferation, migration, and invasion abilities of OS cells. SNHG9 expression was positively regulated by the transcription factor SOX4. SNHG9 interacted with miR-214-5p as a molecular sponge and SOX4 was identified as the target of miR-214-5p. The interaction affected the expression of SNHG9, miR-214-5p, and SOX4, and regulated OS cell proliferation, migration, and invasion. Therefore, the SNHG9/miR-214-5p/SOX4 feedback loop performs an important role in OS progression and might be used as a new potential therapeutic target for the treatment of OS.

Anlotinib for Recurrent or Metastatic Primary Malignant Bone Tumor: A Multicenter, Single-Arm Trial.

Objective: Anlotinib, a novel multitarget kinase inhibitor of VEGFR, FGFR, PDGFR and c-Kit, has proven to be effective and safe for refractory soft tissue sarcoma patients, but has not been examined in recurrent or metastatic primary malignant bone tumors in a clinical trial setting. Methods: This is a multicenter single-arm trial. Patients with pathologically proven recurrent or metastatic primary malignant bone tumors were eligible. Anlotinib was administered orally at 12 mg per day. Each cycle consisted of 2 weeks of treatment followed by 1-week off-treatment. The primary endpoint was progression-free survival (PFS), as assessed in the intention-to-treat (ITT) population. Secondary endpoints included objective response rate (ORR), disease control rate (DCR) and overall survival (OS). Adverse events (AEs) were assessed per NCI CTCAE version 4.03. Results: A total of 42 patients were enrolled. Median PFS was 5.3 months (95% CI 3.5-8.4 months) in the overall analysis, 4.8 months (95%CI 3.5-7.1 months) in osteosarcoma patients and 2.8 months [95%CI 1.3 months to not reached (NR)] in chondrosarcoma patients. The median OS was 11.4 months (95% CI 10.1 months to NR) in the overall analysis, not reached (95% CI, NR, NR) in osteosarcoma patients and 11.4 months (95% CI 1.8 to 21.1 months) in chondrosarcoma patients. The ORR was 9.52% and DCR was 78.57%. Grade 3 or above AEs occurred in 54.76% of the patients, and included hypertension (19.05%), hypertriglyceridemia (9.52%) and pustulosis palmaris et plantaris (7.14%). No treatment-related death was reported. Conclusion: Anlotinib demonstrated promising antitumor activities in recurrent or metastatic primary malignant bone tumors with manageable AEs.

Phase II Study of TQB2450, a Novel PD-L1 Antibody, in Combination with Anlotinib in Patients with Locally Advanced or Metastatic Soft Tissue Sarcoma.

PURPOSE: To explore the efficacy and safety of TQB2450 combined with anlotinib in patients with locally advanced or metastatic soft-tissue sarcoma (LA/M STS). PATIENTS AND METHODS: This was a single arm phase II study (TQB2450-Ib-02 study) performed at two hospitals in China to assess the potency of TQB2450 combined with anlotinib in patients with LA/M STS. Patients were previously unresponsive to at least one chemotherapy regimen. Anlotinib (12 mg every day) was administered orally from day 1 to day 14 every 3 weeks. TQB2450 was administered by intravenous infusion at 1,200 mg on day 1 every 3 weeks. The primary endpoint was the objective response rate (ORR). The secondary endpoints included progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and safety. RESULTS: Between January 2019 and June 2020, 30 patients were enrolled. The ORR was 36.67% and the DCR was 76.67%. The median PFS was 7.85 months [95% confidence interval (CI), 2.89-23.06] and the median OS was not reached [95% CI, 10.58-not estimable (NE)]. Among the patients with alveolar soft part sarcoma (ASPS; 12/30, 40%), the ORR was 75% and the median PFS was 23.06 months (95% CI, 8.97-NE). The most common treatment related adverse events were hypothyroidism (76.67%), hypertriglyceridemia (63.33%), hypercholesterolemia (60.00%), and elevated blood lactate dehydrogenase (53.33%). CONCLUSIONS: The study showed the promising activity in patients with ASPS, also indicating the trend of treatment efficacy in other sarcomas. The toxicity was tolerable. More studies with larger sample size and controlled arm were warranted.

The efficacy of 99mTc-rituximab as a tracer for sentinel lymph node biopsy in cutaneous melanoma patients.

Background: The sentinel lymph node (SLN) status is a vital prognostic factor for malignant melanoma (MM) patients. There is increasing evidence that a radioactive agent, rather than its combination with blue dye, is sufficient for a SLN biopsy (SLNB). Thus, we discussed the efficacy of 99mTc-rituximab as a tracer in MM patients. Methods: A total of 502 consecutive patients with MM who underwent SLNB were enrolled in this study. All participants were peritumorally injected with 99mTc-rituximab before imaging, and scanned with single-photon emission computed tomography-computed tomography (SPECT-CT) to detect the number and location of the SLN. A gamma detection probe was employed to detect radioactive SLNs in operation. Follow up was conducted to observe whether nodal or distant recurrence occurred. Results: The SLNs were successfully imaged via SPECT-CT and harvested from all 502 participants. No drainage tube was indwelled and 32 (6.3%) participants experienced the following complications: seroma (n=26, 5.2%), wound infections or lymphangitis (n=6, 1.2%), sensory nerve injuries (n=4, 0.8%). There were 380 patients who were diagnosed as SLN-negative and 122 (24.2%) were SLN-positive. A total of 85 SLN-positive patients received complete lymph node dissection, and 28 (32.9%) had additional positive lymph nodes. During a median follow-up of 24 months, 28 participants were found to have a false negative (FN) SLN. The FN rate was 18.7%. A higher T stage was a predictive factor for FN [odds ratio (OR) 1.77; P<0.05]. There was no significant difference in the positive or FN rate between the acral and cutaneous groups. Conclusions: The radiopharmaceutical 99mTc-rituximab could be employed as a simple and safe tracer in acral and cutaneous melanoma SLN biopsies.

Real-world experience with pembrolizumab in patients with advanced soft tissue sarcoma.

BACKGROUND: The goal of this study was to retrospectively analyze the efficacy and safety of pembrolizumab in the real-world treatment of soft tissue sarcoma (STS). METHODS: We analyzed 38 patients who suffered from STS and received pembrolizumab treatment from July 2017 to December 2018 in our hospital. We investigated the influence of clinical characteristics, treatment timing, and treatment protocol on objective response rate (ORR). We also investigated the factors affecting overall survival (OS) and progression-free survival (PFS), as well as the occurrence of severe adverse events (SAEs). RESULTS: The overall ORR was 19.4% (7/36). The ORRs of patients who received pembrolizumab treatment as first-line, second-line, and third-line therapy were 42.9% (3/7), 25.0% (4/16), and 0% (0/13), respectively, which showed marginal significance (P=0.052). Four patients (11.1%) maintained a complete response (CR) or partial response (PR) for at least 6 months with pembrolizumab monotherapy, or after withdrawal of chemotherapy or targeted therapy regimens. The median PFS was 2.9 months [95% confidence interval (CI): 2.4-3.4 months] and the median OS was 12.0 months (95% CI: 10.2-13.8 months). Cox regression analysis showed that treatment time was an independent factor affecting PFS (P=0.041), while Eastern Cooperative Oncology Group (ECOG) performance status (PS) score was the only independent factor affecting OS (P=0.028). CONCLUSIONS: In the real world, the effectiveness of pembrolizumab in the treatment of STS was low. Some subtypes showed a limited response to pembrolizumab, including alveolar soft part sarcoma (ASPS), undifferentiated pleomorphic sarcoma (UPS), exoskeletal chondrosarcoma (ESCS), and angiosarcoma (AS), while the response in leiomyosarcoma (LMS) was low. Combination therapy may increase the risk of SAEs, especially when combined with pazopanib.

Surgical drainage after limb salvage surgery and endoprosthetic reconstruction: is 30 mL/day critical?

BACKGROUND: Periprosthetic infection is a major cause of failure after segmental endoprosthetic reconstruction. The purpose of this study is to determine whether certain aspects of drain output affect infection risk, particularly the 30 mL/day criterion for removal. METHODS: Two hundred and ninety-five patients underwent segmental bone resection and lower limb endoprosthetic reconstruction at one institution. Data on surgical drain management and occurrence of infection were obtained from a retrospective review of patients' charts and radiographs. Univariate and multivariate Cox regression analyses were performed to identify factors associated with infection. RESULTS: Thirty-one of 295 patients (10.5%) developed infection at a median time of 13 months (range 1-108 months). Staphylococcus aureus was the most common organism and was responsible for the majority of cases developing within 1 year of surgery. Mean output at the time of drain removal was 72 mL/day. Ten of 88 patients (11.3%) with ≤ 30 mL/day drainage and 21 of 207 patients (10.1%) with > 30 mL/day drainage developed infection (p = 0.84). In multivariate analysis, independent predictive factors for infection included sarcoma diagnosis (HR 4.13, 95% CI 1.4-12.2, p = 0.01) and preoperative chemotherapy (HR 3.29, 95% CI 1.1-9.6, p = 0.03). CONCLUSION: Waiting until drain output is < 30 mL/day before drain removal is not associated with decreased risk of infection for segmental endoprostheses of the lower limb after tumor resection. Sarcoma diagnosis and preoperative chemotherapy were independent predictors of infection.

Target therapy for metastatic alveolar soft part sarcoma: a retrospective study with 47 cases.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a translocation-associated soft-tissue tumor resistant to conventional cytotoxic agents. This report aims to compare the efficacy of anlotinib versus pazopanib as targeted monotherapy in metastatic ASPS and to determine the impact of drug dosage reduction on disease control. METHODS: Sixteen and 31 patients with metastatic ASPS were respectively treated with anlotinib and pazopanib monotherapy at a single institution. Objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were retrieved and compared between both therapeutic arms. Adverse events (AEs) within each group were recorded. Kaplan-Meier survivorship curves computed the impact of drug dosage reduction on PFS. RESULTS: The anlotinib group showed an ORR of 31.2%, compared to 35.5% in the pazopanib arm (P=0.772). Median PFS was 23.6 months [95% confidence interval (CI), 16.2-31.0 months] in patients treated with anlotinib, but dropped to 13.7 months (95% CI, 10.8-16.7 months) in those managed with pazopanib (P=0.023). One (6.3%) patient on anlotinib and 11 (35.5%) on pazopanib developed AEs requiring drug dosage reduction (P=0.029), which significantly reduced patients' PFS in the latter setting (10.5 vs. 15.8 months, P=0.012). In patients without dosage reduction, anlotinib showed a bordering advantage than pazopanib on median PFS (24.5 vs. 15.8 months, P=0.112). CONCLUSIONS: Compared to pazopanib, anlotinib yielded longer PFS and lower incidence of AEs in ASPS patients. Drug dosage reduction was more frequently encountered with the former agent and affected the disease control.

KIF18B promotes tumor progression in osteosarcoma by activating ß-catenin.

Objective: Osteosarcoma is a common primary highly malignant bone tumor. Kinesin family member 18B (KIF18B) has been identified as a potential oncogene involved in the development and metastasis of several cancer types. While KIF18B overexpression in osteosarcoma tissue is clearly detected, its specific function in the disease process remains to be established. Methods:KIF18B expression was assessed in osteosarcoma tissues and cells. We additionally evaluated the effects of KIF18B on proliferation, migration, and invasion of osteosarcoma cells, both in vitro and in vivo. Results: Our results showed overexpression of KIF18B in osteosarcoma tissues and cells. Knockdown of KIF18B induced G1/S phase arrest and significantly inhibited proliferation, migration, and invasion of osteosarcoma cells, both in vitro and in vivo. KIF18B regulated ß-catenin expression at the transcriptional level by controlling nuclear aggregation of ATF2 and at the post-transcriptional level by interacting with the adenomatous polyposis coli (APC) tumor suppressor gene in osteosarcoma cells. Conclusions: KIF18B plays a carcinogenic role in osteosarcoma by regulating expression of ß-catenin transcriptionally via decreasing nuclear aggregation of ATF2 or post-transcriptionally through interactions with APC. Our collective findings support the potential utility of KIF18B as a novel prognostic biomarker for osteosarcoma.

The Notch Pathway Promotes Osteosarcoma Progression through Activation of Ephrin Reverse Signaling.

Despite significant advancements in the diagnosis and treatment of osteosarcoma, the molecular mechanisms underpinning disease progression remain unclear. This work presents strong clinical and experimental evidence demonstrating that Notch signaling contributes to osteosarcoma progression. First, using a cohort of 12 patients, Notch genes were upregulated in tumors compared with adjacent normal tissue, and high tumor expression of Notch1 intercellular domain (NICD1) and the Notch target gene Hes1 correlated with poor chemotherapy response. Data mining of publicly available datasets confirmed that expression of Notch pathway genes is related to poor prognosis in osteosarcoma. On the basis of in vitro analysis, Notch signaling promoted osteosarcoma proliferation, enhanced chemoresistance, facilitated both migration and invasion, and upregulated stem cell-like characteristics. Xenograft models demonstrated that Notch signaling promotes primary tumor growth and pulmonary metastasis, and Notch inhibition is effective in reducing tumor size and preventing metastasis. Mechanistically, activated Notch signaling induces the expression of ephrinB1 and enhances the tumor-promoting ephrin reverse signaling. Overall, these findings provide functional evidence for Notch pathway genes as candidate biomarkers to predict prognosis in patients with osteosarcoma, and suggest a mechanistic rationale for the use of Notch inhibitors to treat osteosarcoma. IMPLICATIONS: The study provides preclinical evidence for Notch pathway as a molecular marker to predict osteosarcoma prognosis and as a therapeutic target against osteosarcoma. In addition, we identified a novel mechanism that ephrin reverse signaling acts as a key mediator of Notch pathway.

ONZIN Upregulation by Mutant p53 Contributes to Osteosarcoma Metastasis Through the CXCL5-MAPK Signaling Pathway.

BACKGROUND/AIMS: Gain-of-function of mutant p53 is associated with a high rate of lung metastasis in osteosarcoma. To investigate the mechanism of mutant p53-induced osteosarcoma metastasis, expression array analysis was performed, comparing non-metastatic osteosarcomas from p53+/- mice with metastatic osteosarcomas from p53R172H/+ mice. Onzin (Plac8) was identified as one of the genes upregulated in p53R172H/+ mouse metastatic osteosarcomas. Accordingly, we investigated the role of ONZIN in human osteosarcoma metastasis. METHODS: ONZIN function and its downstream targets were examined in osteosarcoma cell lines. Assays related to tumorigenesis and metastasis, including cell migration, invasion, clonogenic survival, and soft agar colony formation, were performed in osteosarcoma cells. Additionally, mouse xenograft models were used to examine the role of ONZIN overpression in tumorigenesis in vivo. Lastly, 87 osteosarcoma patients were recruited to investigate the clinical relevance of ONZIN overexpression in metastasis and prognosis. RESULTS: ONZIN overexpression enhanced osteosarcoma cell proliferation, clonogenic survival, migration, and invasion independent of p53 status. Furthermore, ONZIN overexpression induced CXCL5 upregulation and resulted in increased ERK phosphorylation, which contributed to more aggressive osteosarcoma metastatic phenotypes. More importantly, overexpression of ONZIN in human osteosarcoma patients was closely associated with lung metastasis, poor prognoses, and survival. CONCLUSIONS: Overexpression of ONZIN promotes osteosarcoma progression and metastasis, and can serve as a clinical biomarker for osteosarcoma metastasis and prognosis.

AZGP1 inhibits soft tissue sarcoma cells invasion and migration.

BACKGROUND: One of the major challenges in soft tissue sarcomas is to identify factors that predict metastasis. AZGP1 is a potential biomarker of cancer progression, but its value in soft tissue sarcomas remains unknown. The aim of this study is to determine the expression level of AZGP1 in soft tissue sarcomas, and to analyze its influence on tumor progression. METHODS: AZGP1 immunohistochemistry (IHC) and RT-PCR were performed in 86 patients with soft tissue sarcomas. The relationships between AZGP1 levels and clinicopathologic features were analyzed. In vitro experiments were performed using fibrosarcoma (HT1080), rhabdomyosarcoma (RD) and synovial sarcoma (SW982) cell lines to corroborate our findings. We used lentiviral over-expression and knockdown assays to examine how changes of AZGP1 expressions might affect cellular migration and invasion. RESULTS: The quantitative RT-PCR results showed that AZGP1 expression was negatively correlated with metastasis and overall survival in soft tissue sarcomas (p < 0.05). Immunohistochemical staining showed lower expression of AZGP1 in patients with metastasis than in those without. Kaplan-Meier survival analysis showed that patients with low expression of AZGP1 had shorter overall (p = 0.056) and metastasis-free survivals (p = 0.038). These findings were corroborated by our in vitro experiments. Over-expression of AZGP1 significantly decreased RD cellular migration and invasion by 64% and 78%, respectively. HT1080 cells migration was inhibited by 2-fold, whereas their invasion was repressed by 7-fold after AZGP1 knockdown. CONCLUSIONS: Our study reveals that reduced AZGP1 expression correlates with in vitro cellular migration and invasion. In vivo, it is associated with higher metastatic risk and shorter survival in patients with soft tissue sarcomas.

Efficacy of vinorelbine combined with low-dose methotrexate for treatment of inoperable desmoid tumor and prognostic factor analysis.

OBJECTIVE: To assess the efficacy of conservative chemotherapy for inoperable desmoid tumor (DT) and analyze the prognostic factors. METHODS: From November 2008 to April 2016, 71 patients of inoperable DT were treated with vinorelbine and low-dose methotrexate in the Department of Bone and Soft Tissue Tumors, Peking University Cancer Hospital & Institute, and enrolled in this retrospective study. The chemotherapy duration is one year. The efficacy of chemotherapy and the prognosis were observed. RESULTS: Of the 71 patients, 55% were female. Age of onset varied from 1 to 47 years, and the median age was 14 years. Only 11 (15.5%) cases suffered primary tumor. The distribution of the site of tumors was: 31 (43.7%) in the trunk, 36 (50.7%) in the limbs, and 4 (5.6%) in the peritoneal and pelvic cavity. The size of tumor (the maximum diameter) differed from 2 to 37 cm with a mean of 9.3 cm. The median follow-up duration was 28 (range, 6-87) months. Common side effects included: nausea and vomiting, liver injury, bone marrow suppression and oral ulcers. When the chemotherapy finished, 1 (1.4%) case achieved complete response, 24 (33.8%) achieved partial response, 37 (52.1%) achieved stable disease and 9 (12.7%) had progressive disease. The overall response rate was 87.3%. The progression-free survival (PFS) of the participants were from 6 to 87 months, and the 2-, 3- and 5-year PFS was 79.9%, 68.4% and 36.3%, respectively. No significant difference was identified in PFS in subgroups of gender, age of onset, age of chemotherapy, tumor site and tumor size. CONCLUSIONS: For recurrent, inoperable and progressive DT, enough course of chemotherapy with vinorelbine combined with low-dose methotrexate was an optional choice for local control.

Cisplatin selects for stem-like cells in osteosarcoma by activating Notch signaling.

Notch signaling regulates normal stem cells and is also thought to regulate cancer stem cells (CSCs). Recent data indicate that Notch signaling plays a role in the development and progression of osteosarcoma, however the regulation of Notch in chemo-resistant stem-like cells has not yet been fully elucidated. In this study we generated cisplatin-resistant osteosarcoma cells by treating them with sub-lethal dose of cisplatin, sufficient to induce DNA damage responses. Cisplatin-resistant osteosarcoma cells exhibited lower proliferation, enhanced spheroid formation and more mesenchymal characteristics than cisplatin-sensitive cells, were enriched for Stro-1+/CD117+ cells and showed increased expression of stem cell-related genes. A similar effect was observed in vivo, and in addition in vivo tumorigenicity was enhanced during serial transplantation. Using several publicly available datasets, we identified that Notch expression was closely associated with osteosarcoma stem cells and chemotherapy resistance. We confirmed that cisplatin-induced enrichment of osteosarcoma stem cells was mediated through Notch signaling in vitro, and immunohistochemistry showed that cleaved Notch1 (NICD1) positive cells were significantly increased in a relapsed xenograft which had received cisplatin treatment. Furthermore, pretreatment with a γ-secretase inhibitor (GSI) to prevent Notch signalling inhibited cisplatin-enriched osteosarcoma stem cell activity in vitro, including Stro-1+/CD117+ double positive cells and spheroid formation capacity. The Notch inhibitor DAPT also prevented tumor recurrence in resistant xenograft tumors. Overall, our results show that cisplatin induces the enrichment of osteosarcoma stem-like cells through Notch signaling, and targeted inactivation of Notch may be useful for the elimination of CSCs and overcoming drug resistance.