Mid- to long-term effects of two different biological reconstruction techniques for the treatment of humerus osteosarcoma involving caput humeri.

BACKGROUND: The proximal humerus is one of the most common sites of primary or metastatic malignant tumors. Reconstruction of the shoulder after tumor resection is controversial and challenging. When intra-articular resection is performed, biological reconstruction (osteoarticular allograft and autologous bone implantation) may be the first choice rather than prosthetic reconstruction. OBJECTIVE: To observe the mid- to long-term effects of oncologic, reconstructive, and functional outcomes of two different biological reconstruction methods for resection of humerus osteosarcoma involving caput humeri. METHODS: This was a retrospective study of 13 consecutive patients who underwent humeral reconstruction of osteosarcoma including caput humeri using osteoarticular allograft (n = 7) and tumor bone inactivated and reimplantation (TBIR, n = 6) in our clinic between 2007 and 2017. Patients' general information, resection and reconstruction techniques, oncological and functional outcomes, and complications were collected and evaluated. Different complications of implantations were compared and analyzed for the different biological methods. RESULTS: The study included ten males and three females with an average age of 19.15 years. The operation time was about 3.65 h with an average blood loss of 631 ml. The resection tumor bones were 13-45 cm (23.54 cm on average). The mean follow-up period was 5.27 years. The shoulder movement was 10-70° (average, 44.00°) in abduction, 0-30° (average, 14.17°) in flexion, and 0-20° (average, 11.90°) in extention at the last follow-up. The complications included fracture in four TBIR patients and two allograft patients with an average of 2.67 years postoperation. Fracture rate was higher and appeared time was earlier in TBIR patients than in allograft patients (p = 0.04); caput humeri absorption occurred in all seven allograft patients and three TBIR patients at an average of 3.10 years after surgery; severe graft bone resorption appeared in five TBIR patients and two allograft patients at an average of 2.57 years of follow-up. CONCLUSIONS: Humerus biological reconstruction involving caput humeri was associated with a high complication rate and acceptable limb function in the mid to long term. New combined biological methods should be explored and adopted in the future.

Tumor necrosis factor-α- and interleukin-1ß-dependent matrix metalloproteinase-3 expression in nucleus pulposus cells requires cooperative signaling via syndecan 4 and mitogen-activated protein kinase-NF-κB axis: implications in inflammatory disc disease.

Matrix metalloproteinase-3 (MMP-3) plays an important role in intervertebral disc degeneration, a ubiquitous condition closely linked to low back pain and disability. Elevated expression of syndecan 4, a cell surface heparan sulfate proteoglycan, actively controls disc matrix catabolism. However, the relationship between MMP-3 expression and syndecan 4 in the context of inflammatory disc disease has not been clearly defined. We investigated the mechanisms by which cytokines control MMP-3 expression in rat and human nucleus pulposus cells. Cytokine treatment increased MMP-3 expression and promoter activity. Stable silencing of syndecan 4 blocked cytokine-mediated MMP-3 expression; more important, syndecan 4 did not mediate its effects through NF-κB or mitogen-activated protein kinase (MAPK) pathways. However, treatment with MAPK and NF-κB inhibitors resulted in partial blocking of the inductive effect of cytokines on MMP-3 expression. Loss-of-function studies confirmed that NF-κB, p38α/ß2/γ/δ, and extracellular signal-regulated kinase (ERK) 2, but not ERK1, contributed to cytokine-dependent induction of MMP3 promoter activity. Similarly, inhibitor treatments, lentiviral short hairpin-p65, and short hairpin-IκB kinase ß significantly decreased cytokine-dependent up-regulation in MMP-3 expression. Finally, we show that transforming growth factor-ß can block the up-regulation of MMP-3 induced by tumor necrosis factor (TNF)-α by counteracting the NF-κB pathway and syndecan 4 expression. Taken together, our results suggest that cooperative signaling through syndecan 4 and the TNF receptor 1-MAPK-NF-κB axis is required for TNF-α-dependent expression of MMP-3 in nucleus pulposus cells. Controlling these pathways may slow the progression of intervertebral disc degeneration and matrix catabolism.

Preliminary clinical research on epiphyseal distraction in osteosarcoma in children.

BACKGROUND: The feasibility of distal femur epiphysis preservation through epiphyseal distraction by external fixator in childhood osteosarcoma was explored. METHODS: Between July 2007 and May 2011, 10 children who were suffering from distal femur osteosarcoma received epiphyseal distraction by external fixator, combined with tumor resection and repair with massive allograft bone to preserve the epiphysis of the distal femur and knee function. There were six male and four female patients, 9- to 14-years old (average 10.5 years old). The tumors were staged clinically according to the Enneking staging method: six cases were classified as stage in IIA and four cases as stage in IIB. All patients were diagnosed by biopsy, then received chemotherapy before and after surgery. All patients received tumor bone resection and the defects of the bone were repaired with massive allograft bone that was fixed by intramedullary nails; the distracted epiphysis and allograft bone were fixed with cancellous screws. RESULTS: All cases received follow-up from 15 to 56 months (average 38.5 months). There were no local recurrences. One case died of lung metastasis and one case had poor incision healing for rejection of allograft bone. According to the functional evaluation criteria of the International Society of Limb Salvage (ISOLS) after operation, five cases were rated excellent, four cases good and one case fair. The ratio of excellent or good was 90.0%. There was no statistically significant difference in length between the operated and the normal lower limbs during the last review. CONCLUSIONS: Epiphyseal distraction by external fixator can result in satisfactory limb length and joint function for children with a malignant bone tumor.

Comparison of morphology and biocompatibility of acellular nerve scaffolds processed by different chemical methods.

To investigate the morphological differences among acellular rat nerve scaffolds processed by different chemical methods and compare the biocompatibility between rat nerve grafts processed by different chemical methods and rat adipose-derived stem cells in vitro. Acellular rat sciatic nerve scaffolds processed by two different chemical methods (the Sondell method and the optimized method) and normal rat sciatic nerves were used as control. The structure and components of nerve scaffold were observed under microscopy, the degrees of decellularization and demyelination of nerve scaffold and integrity of nerve fiber tubes were assessed. The rat adipose-derived stem cells growth and adherence on scaffold were studied by scanning electron microscopy, the activity and adhesive ratio of rat adipose-derived stem cells in the nerve scaffold were compared. The basal lamina tubes and the extracellular matrix in the epineurium and perineurium in the nerve graft of optimized method were better preserved than the nerve graft of the Sondell method. After co-cultured with scaffolds, the difference of cell activity between three groups (two cell-scaffold combinations and control group) at the same observation time were not statistically significant (P > 0.05),the adhesive ratio of rat adipose-derived stem cells in the scaffold of the optimized method was better than that of the Sondell method. The scaffold of the optimized method is more effective than the scaffold of the Sondell method for peripheral nerve tissue engineering.

Combination of acellular nerve graft and schwann cells-like cells for rat sciatic nerve regeneration.

OBJECTIVE: To investigate the effect of tissue engineering nerve on repair of rat sciatic nerve defect. METHODS: Forty-five rats with defective sciatic nerve were randomly divided into three groups. Rats in group A were repaired by acellular nerve grafts only. Rats in group B were repaired by tissue engineering nerve. In group C, rats were repaired by autogenous nerve grafts. After six and twelve weeks, sciatic nerve functional index (SFI), neural electrophysiology (NEP), histological and transmission electron microscope observation, recovery ratio of wet weight of gastrocnemius muscle, regenerated myelinated nerve fibers number, nerve fiber diameter, and thickness of the myelin sheath were measured to assess the effect. RESULTS: After six and twelve weeks, the recovery ratio of SFI and wet weight of gastrocnemius muscle, NEP, and the result of regenerated myelinated nerve fibers in groups B and C were superior to that of group A (P < 0.05), and the difference between groups B and C was not statistically significant (P > 0.05). CONCLUSION: The tissue engineering nerve composed of acellular allogenic nerve scaffold and Schwann cells-like cells can effectively repair the nerve defect in rats and its effect was similar to that of the autogenous nerve grafts.

A Phase 1a/1b Dose Escalation/Expansion Study of the Anti-PD-1 Monoclonal Antibody Nofazinlimab in Chinese Patients with Solid Tumors or Lymphoma.

BACKGROUND: Immune checkpoint blockade with anti-programmed cell death 1 (PD-1) antibodies has demonstrated efficacy in multiple tumor types. Nofazinlimab is a humanized rat antibody targeting PD-1. A first-in-human study of nofazinlimab conducted in Australia found no dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD) was not reached in the range of 1-10 mg/kg. OBJECTIVE: We evaluated nofazinlimab for multiple advanced malignancies in Chinese patients. PATIENTS AND METHODS: This was a phase 1a/1b, open-label, multicenter, dose-escalation/expansion trial. In phase 1a, patients received an abbreviated dose escalation of nofazinlimab at 60 mg and 200 mg every 3 weeks (Q3W) to determine DLTs and the recommended phase 2 dose (RP2D). In phase 1b, patients received the RP2D (monotherapy/combination) in six arms by tumor type; DLTs were evaluated for nofazinlimab plus lenvatinib in the unresectable hepatocellular carcinoma (uHCC) arm. Safety (continuously monitored in patients who received nofazinlimab) and efficacy (patients with measurable baseline disease) were assessed. RESULTS: Overall, 107 patients were eligible and received nofazinlimab. In phase 1a, no DLTs were observed; the RP2D was 200mg Q3W. In phase 1b, no DLTs were observed with nofazinlimab plus lenvatinib. The safety profile was consistent with that observed in the first-in-human study (NCT03475251). In phase 1b, 21/88 (23.9%) patients achieved confirmed objective responses, 26 (29.5%) had stable disease, and 9/20 (45.0%) patients with uHCC achieved confirmed objective responses to nofazinlimab plus lenvatinib. CONCLUSIONS: Nofazinlimab was well tolerated in Chinese patients. Preliminary efficacy was encouraging, particularly for nofazinlimab plus lenvatinib in uHCC, which is being studied in an ongoing phase 3 trial. CLINICAL TRIAL REGISTRATION: NCT03809767; registered 18 January 2019.

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.

Osteosarcoma in One of Identical Twins: Three Cases Report and a Literature Review.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor occurring mainly in children and young adults. OS is usually seen in sporadic cases, and it is an extremely rare phenomenon in blood relatives, particularly among identical twins. CASE PRESENTATION: The present study reports three cases of OS occurring in only one of identical twins. The first case is a high-grade OS in the left proximal tibia of a 16-year-old girl, treated with neo-adjuvant chemotherapy, en bloc resection, and reconstruction with a modular knee tumor prosthesis. The second one is a high-grade OS of the left proximal tibia of a 6-year-old girl. The patient was treated with neo-adjuvant chemotherapy, en bloc resection, and reconstruction with inactived autograft. The third one is a conventional OS of the right proximal tibia of a 20-year-old woman. She was treated with neo-adjuvant chemotherapy, en bloc resection, and reconstruction with a custom-made prosthesis. CONCLUSIONS: The occurrence of OS in one of identical twins is a relatively rare event but may present the best opportunity to understand the genetic mechanisms underlying the tumorigenesis and progression of this disease in humans. A longer follow-up period and regular imaging evaluation are needed to confirm whether the identical twin of these patients will suffer OS in the future.

Heterogeneity of Soft Tissue Sarcomas and Its Implications in Targeted Therapy.

Soft tissue sarcomas are a set of malignancies of mesenchymal origin. Due to the rarity and similarity in clinical presentation, they are grouped together and treated similarly in clinic. The response rates for current chemotherapy are around 20% and the median overall survival for advanced soft tissue sarcoma are less than 2 years. Thus, the current strategy with identical treatment for all soft tissue sarcomas is far from satisfactory. In this study, we first reviewed the current clinical and genomic findings of soft tissue sarcoma, paying special attention to the heterogeneities among different tumors. Then we reviewed the state-of-art understanding of targeted therapy in soft tissue sarcoma. We observed tremendous heterogeneity both in clinical and genomic settings between different tumors. Individualized treatment plans demonstrated better response and disease control and should be advocated. In summary, heterogeneity of soft tissue sarcomas requires the development of individualized treatment plans such as targeted therapy.

Biological reconstruction in the treatment of extremity sarcoma in femur, tibia, and humerus.

To understand the feasibility, clinical effect, and complications related to biological reconstruction techniques for long limb malignant bone tumors after excision.This retrospective study included eighty patients with malignant bone tumors treated at our hospital between January 2007 and January 2019. After tumor resection, 52 cases of intercalary and 28 cases of osteoarticular bone grafts were used. The implanted bone included devitalized recycling bone, fibular, and allograft.The average follow up period was 42.19 months for 80 patients, among whom 15 (18.75%) died. The 5-year EFS and OS were 58% and 69%, respectively. The average length of the replanted bone was 18.57 cm. The MSTS scores of intercalary and osteoarticular bone grafts were 87.24% and 64.00%, respectively. In 23 cases (44.23%) of metaphyseal and 26 cases (32.5%) of the diaphysis, bone graft union was obtained at the first stage. The factors affecting bone union were the patient's gender, age, devitalization bone methods and whether the implanted bone was completely fixed. Postoperative complications included delayed bone union in 15 patients, fractures in 25 cases, nonunion in 22 cases, bone resorption in 14 cases, and postoperative infection in 4 cases. Twenty-eight cases of bone grafting required revision surgery, including replacement of internal fixation, autologous bone graft, debridement, removal of internal fixation, and replacement with prosthetic replacement.Biological reconstructions with massive bone grafts are useful in the reconstruction of certain malignant extremity bone tumors after wide excision.

Gene expression regulations by long noncoding RNAs and their roles in cancer.

Cancers are deadly diseases. The general mystery of carcinogenesis, primary and acquired drug resistance and distant organ metastasis are still puzzles to be solved. Long noncoding RNAs (lncRNAs) are receiving more and more attention in recent years since their roles in transcriptional regulation have been unveiled. Detailed functional annotations of lncRNAs have showed that their regulatory roles are largely determined by their binding partners. LncRNAs directly bind to DNA, RNA and proteins and regulate gene expression at transcriptional, post-transcriptional and post-translational levels. Here we review the current understanding of molecular functions of lncRNAs, will emphasize on their binding partners and summarize their biological roles in cancer.

Activity and Safety of Geptanolimab (GB226) for Patients with Unresectable, Recurrent, or Metastatic Alveolar Soft Part Sarcoma: A Phase II, Single-arm Study.

PURPOSE: Patients with alveolar soft part sarcoma (ASPS) are rare and have few treatment options. We assessed the activity of geptanolimab (GB226), a fully humanized programmed cell death protein 1 antibody, for patients with unresectable, recurrent, or metastatic ASPS. PATIENTS AND METHODS: We conducted this multicenter, single-arm, phase II study (Gxplore-005, NCT03623581) in patients aged 18-75 years who had unresectable, recurrent, or metastatic ASPS at 11 sites in China. Patients received intravenous geptanolimab (3 mg/kg) every 2 weeks until disease progression or unacceptable toxicity. The primary endpoint was objective response rate assessed by independent review committee (IRC) per RECIST 1.1 in the full analysis set population. RESULTS: Between September 6, 2018 and March 6, 2019, we enrolled and treated 37 patients with 23 (62.2%) having received prior systemic treatment. Fourteen [37.8%; 95% confidence interval (CI), 22.5-55.2] of 37 patients had an objective response assessed by IRC with a 6-month duration of response rate of 91.7%. Median progression-free survival was 6.9 months (95% CI, 5.0-not reached) and disease control was achieved in 32 (86.5%; 95% CI, 71.2-95.5) patients. Three of 37 patients reported grade 3 treatment-related adverse events (TRAEs), including anemia, hypophysitis, and proteinuria [one each (2.7%)]. No grade 4 TRAEs were observed. Two (5.4%) patients discontinued treatment due to TRAEs (one with hypophysitis and one with Mobitz type I atrioventricular block). The baseline percentage of CD4+ T cells was adversely associated with patient response (P = 0.031). CONCLUSIONS: Geptanolimab has clinically meaningful activity and a manageable safety profile in unresectable, recurrent, or metastatic ASPS.

Efficacy and safety of apatinib in treatment of osteosarcoma after failed standard multimodal therapy: An observational study.

Recently, apatinib has been shown to be effective in treating sarcoma. This study aimed to assess the safety and efficacy of apatinib in the treatment of patients with osteosarcoma after failed of standard multimodal therapy and to compare the therapeutic effects of apatinib on osteosarcoma between high-dose group and low-dose group.A total of 27 patients with osteosarcoma who received apatinib between January 2016 and August 2017 were retrospectively reviewed. Among the 27 patients, the objective response rate (ORR) and the disease control rate (DCR) were 25.93% and 66.67%, respectively. The median of progression-free survival (m-PFS) was 3.5 months (95% confidence interval [CI], 2.5-4.8 months), and the median of overall survival (m-OS) was 9.5 months (95% CI, 7.8-10.5 months). There was no statistically significant difference in ORR (36.36% vs 18.75%), DCR (63.64% vs 68.75%), m-PFS (4.3 months [95% CI, 1.8-7 months) vs 3.35 months (95% CI, 1.8-4 months]), and m-OS (9.5 months [95% CI, 7.8-10.5 months] vs 9.4 months [95% CI, 7.8-10.8 months]) (P > .05) between the high-dose group (the average dose was 659 mg/qd) and the low-dose group (the average dose was 516 mg/qd). Most of the adverse events (AEs) were in grade 1 or grade 2. The main AEs in grade 3 were hypertension, rash, weight loss, hand-foot syndrome, and diarrhea.Apatinib is safe and effective in the treatment of advanced osteosarcoma. We recommend that the initial dose of apatinib should be 500 mg/qd in the treatment of osteosarcoma.

Upregulation of ALDH1B1 promotes tumor progression in osteosarcoma.

Osteosarcoma (OS) is the most common primary malignant bone tumor in childhood and adolescence with poor prognosis. The mechanism underlying tumorigenesis and development of OS is largely unknown. ALDH1B1 has been reported to involve in many kinds of human cancers and functions as an oncogene, but the role of ALDH1B1 in OS has not been investigated comprehensively. In the present study, we aimed to examine clinical value and biological function of ALDH1B1 in OS. Firstly, we investigated the roles of ALDH1B1 on an OS tissue microarray (TMA) as well as two OS cohorts from GEO database. We found that ALDH1B1 was significantly up-regulated in OS tissues and was independently associated with poor prognosis. Moreover, ALDH1B1 silencing could suppress the proliferation, migration, invasion in vitro and inhibit the growth of xenograft tumor and of OS cells in vivo. Additional, ALDH1B1 knockdown increased the apoptosis rate and lead to cell cycle arrest in G1 stage of OS cell in vitro. More importantly, the inhibition of ALDH1B1 expression could increase the sensitivity of OS cells to chemotherapy, which suggested that ALDH1B1 might be served as a therapeutic target to reverse drug resistance in chemotherapy in OS patients. Taken together, our founding suggested that ALDH1B1 contributes to OS tumor progression and drug resistance, which may represent a novel prognostic marker and potential therapeutic target for OS patients.

Treatment of osteosarcoma around the knee in skeletally immature patients.

Limb sparing surgery in growing young patients with malignant tumors is difficult as invasion of the physis by the tumor or surgical resection through the metaphysis may cause significant limb discrepancy following surgery. At present, hinged tumor prosthesis or biological reconstructions are the main methods following tumor resection in these patients. The aim of the present study was to assess different procedures for the treatment of osteosarcoma around knee joints in immature patients. A retrospective study of 56 patients (<15 years old, open physis) who had been treated for osteosarcoma around the knee joint between January 2007 and December 2015 was performed. Clinical data collected included patient demographics (age at diagnosis, sex and date of diagnosis), tumor characteristics [location, Enneking stage and subtype on magnetic resonance imaging (MRI)], treatment (response to neoadjuvant chemotherapy and type of primary surgery) and clinical outcomes (limb function, discrepancy and overall survival). The median age at the time of diagnosis was 12.14 years (range, 3-15 years). There were 32 male patients (57.1%). A total of 41 (82%) tumors were located at the distal femur, and 15 (18%) at the proximal tibia. A total of 49 (87.5%) patients were diagnosed with stage IIB tumors, and 7 (12.5%) had stage III, according to the Enneking stage classification. Different surgical methods, including amputation, rotation-plasty, endoprosthesis and biological instructions (e.g., allograft) were performed according to MRI type classification. During follow-up, 21 patients (37.5%) succumbed to disease. The Musculoskeletal Tumor Society score ranged from excellent to fair functional result. Recurrence (2 cases, 16.67%) and infection (2, cases, 16.67%) were the main complications following endoprosthesis replacement, while delayed union (12 cases, 57.14%) and fracture (3 cases, 14.29%) were the main causes for biological reconstructions. Limb-length discrepancy ranged from 0-10 cm in limb-saving surgery. The overall survival rate was 57.66% with different cohorts in Enneking stages IIB and III, with or without involvement of the physis and different cycles of chemotherapy. Results of the present study indicated that different limb saving surgeries, including epiphysis/physis preservation with biological construction in patients with MRI types I to III and endoprosthetic/osteoarticular reconstruction in patients with MRI types IV and V, are useful in the management of osteosarcoma in growing young patients with proper surgery indications, and knee joint function was maintained with acceptable complications including limb discrepancy, delayed union, infection, recurrence and fracture.

LDHB may be a significant predictor of poor prognosis in osteosarcoma.

Osteosarcoma is the most common primary malignant bone tumor in children and young adults. Lactate dehydrogenase (LDH) is considered as the key glycolytic enzyme and involved in tumor initiation and metabolism. Here, we firstly found that LDHB was highly expressed in osteosarcoma cell lines. Expression profiling indicated that LDHB mRNA was elevated in osteosarcoma tissues with metastasis versus without metastasis, and LDHB high expression predicted a poor prognosis in patients. After LDHB knockdown by siRNA transfection, cell growth and proliferation were inhibited and presented a dose-dependent cell death via MTT assay. Meanwhile, wound healing and matrigel invasion assay revealed that LDHB knockdown inhibited migration and invasion activities in osteosarcoma cells. We further constructed tissue microarray in 40 osteosarcoma tissues. Correlation between LDHB and clinicopathological features indicated that LDHB expressions were associated with tumor TNM stage, recurrence and survival. Kaplan-Meier survival curve revealed that overall survival was significantly decreased in patients with high expression of LDHB. Patients with recurrence or advanced stage showed an increased LDHB, suggesting that increased LDHB was closely associated with a poor prognosis in osteosarcoma patients. Thus, LDHB can be considered as a prognostic marker for tumor recurrence and poor overall survival in osteosarcoma.

Up-regulation of HDAC9 promotes cell proliferation through suppressing p53 transcription in osteosarcoma.

Increasing studies have demonstrated that altered expression of histone deacetylases (HDACs) plays a critical role in the tumorigenesis through up-regulation or down-regulation of key genes involved in cell proliferation, cell-cycle regulation and apoptosis. In the present study, the expression and function of HDAC9 were investigated in osteosarcoma. Quantitative real-time PCR and Western blot analysis found that HDAC9 was up-regulated in osteosarcoma tissues, when compared with that in adjacent normal tissues. In vitro studies further demonstrated that overexpression of HDAC9 in U2OS and MG63 cells promoted cell proliferation and invasion. Using chromatin immunoprecipitation (ChIP) assay, we found that HDAC9 epigenetically repressed p53 transcription through binding to its proximal promoter region. Therefore, our data suggest an important role for HDAC9/p53 regulatory pathway in the osteosarcoma progression.

Different methods for inducing adipose-derived stem cells to differentiate into Schwann-like cells.

INTRODUCTION: The aim of the study was to explore an effective method to induce adipose-derived stem cells (ADSCs) to differentiate into Schwann-like cells in vitro. MATERIAL AND METHODS: Reagents were applied in two different ways (Dezawa inducing method and modified inducing method) in which inducers including ß-mercaptoethanol (ß-ME), all-trans-retinoic acid (ATRA), type I collagenase, forskolin, heregulin, basic fibroblast growth factor (BFGF) and brain-derived neurotrophic factor (BDNF) were used in different ways to induce ADSCs of rats to differentiate into Schwann-like cells. After induction, the cell morphologic characteristics and the cellular immunohistochemical staining positive rate of anti-S100 and anti-GFAP (glial fibrillary acidic protein) antibodies and the gray value of immunocytochemical dye with anti-S100 and anti-GFAP antibodies and cell activity measured by the MTT method were compared with each other to evaluate the induction effects. RESULTS: Both methods can induce differentiation of ADSCs of rats into Schwann-like cells, but the cellular morphology of the modified method was more similar to Schwann cells than that of the Dezawa inducing method, there was a higher cellular immunohistochemical staining positive rate and staining grey value in immunocytochemical dye with anti-S100 and anti-GFAP antibodies, and less damage in the cell activity of the modified inducing method than that of the Dezawa inducing method. CONCLUSIONS: The effect of the modified method to induce ADSCs to differentiate into Schwann-like cells in vitro is superior to that of the Dezawa inducing method.

TRAF4 enhances osteosarcoma cell proliferation and invasion by Akt signaling pathway.

TRAF4, or tumor necrosis factor receptor-associated factor 4, is overexpressed in several cancers, suggesting a specific role in cancer progression. However, its functions in osteosarcoma are unclear. This study aimed to explore the expression of TRAF4 in osteosarcoma tissues and cells, the correlation of TRAF4 to clinical pathology of osteosarcoma, as well as the role and mechanism of TRAF4 in osteosarcoma metastasis. The protein expression levels of TRAF4 in osteosarcoma tissues and three osteosarcoma cell lines, MG-63, HOS, and U2OS, were assessed. Constructed TRAF4 overexpression vectors and established TRAF4 overexpression of the U2OS cell line. Cell proliferation, cell invasion, protein levels, and TRAF4 phosphorylations were assessed following TRAF4 transfection, as well as the effects of TRAF4 siRNA on cell proliferation and invasion. The results show that TRAF4 protein levels in osteosarcoma tissues were significantly higher than that in normal bone tissues. Importantly, an obvious upregulation of TRAF4 was found in carcinoma tissues from patients with lung metastasis compared with patients without lung metastasis. Consistently, a similar increase in TRAF4 mRNA and protein was also demonstrated in the osteosarcoma cell lines MG-63, HOS, and U2OS compared to normal bone cells, hFOB1.19. When TRAF4 was overexpressed in U2OS cells, cell proliferation was significantly enhanced, accompanied by an increase in Ki67 expression and colony formation. Compared with the control and vector-treated groups, TRAF4 transfection increased the invasion potential of U2OS cells (p < 0.05). Interestingly, TRAF4 transfection significantly enhanced the phosphorylation of Akt. After blocking Akt with its specific siRNA, TRAF4-induced cell proliferation and invasion were dramatically attenuated. In summary, our findings demonstrated that TRAF4 enhances osteosarcoma cell proliferation and invasion partially by the Akt pathway. This work suggests that TRAF4 might be an important target in osteosarcoma.

Knockdown of TRAF4 expression suppresses osteosarcoma cell growth in vitro and in vivo.

Tumor necrosis factor (TNF) receptor-associated factor 4 (TRAF4) is an adapter molecule that is overexpressed in certain cancers. TRAF4 is overexpressed in osteosarcoma tissues and osteosarcoma cells. Using the technique of RNA interference, the expression of TRAF4 in the human osteosarcoma Saos-2 cell line was shown to be downregulated. The proliferation, cell cycle arrest and apoptosis ability of Saos­2 cells were examined, as was tumor development in a xenograft mouse model. The results showed that the TRAF4 knockdown exerts inhibitory effects on the proliferation ability of Saos-2 cells and tumor development in a xenograft mouse model. Simultaneously, it was found that TRAF4 knockdown led to cell cycle arrest in the G1 phase and promoted Saos-2 cell apoptosis. Following TNF-α treatment, the expression of nuclear factor κB was significantly reduced in the TRAF4­small interfering RNA group. These results indicate that TRAF4 regulated osteosarcoma cell growth in vitro and in vivo, and offers a candidate molecular target for osteosarcoma prevention and therapy.