Studying the mechanism underlying lipid metabolism in osteosarcoma based on transcriptomic RNA sequencing and single-cell data.

BACKGROUND: We aimed to provide a new typing method for osteosarcoma (OS) based on single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq data from the perspective of lipid metabolism and examine its potential mechanisms in the onset and progression of OS. METHODS: Scores for six lipid metabolic pathways were calculated by single-sample gene set enrichment analysis (ssGSEA) based on a scRNA-seq dataset and three microarray expression profiles. Subsequently, cluster typing was conducted using unsupervised consistency clustering. Furthermore, single-cell clustering and dimensionality-reduction analyses identified cell subtypes. Finally, an analysis of cellular receptors was performed using CellphoneDB to identify cellular communication. RESULTS: OS was classified into three subtypes based on lipid metabolic pathways. Among them, patients in clust3 showed poor prognoses, whereas those in clust1 and clust2 exhibited good prognoses. In addition, ssGSEA analysis showed that patients in clust3 had lower immune cell scores. Moreover, the Th17 cell differentiation pathway was significantly differentially enriched between clust2 and clust3, with lower enrichment scores for metabolic pathways in the former relative to clust1 and clust2. In total, 24 genes were upregulated between clust1 and clust2, whereas 20 were downregulated in clust3. These observations were validated by single-cell data analysis. Finally, through scRNA-seq data analysis, we identified nine ligand-receptor pairs particularly critical for communication between normal and malignant cells. CONCLUSIONS: Three clusters were identified and the single-cell analysis revealed that malignant cells dominated lipid metabolism patterns in tumors, thereby influencing the tumor microenvironment.

Construction of a novel mRNAsi-related risk model for predicting prognosis and immunotherapy response in osteosarcoma.

Background: Targeting cancer stem cells (CSC) may represent a future therapeutic direction for osteosarcoma (OS), which mainly relies on the identification of CSC markers. This study aimed to classify OS based on messenger ribonucleic acid (mRNA) stemness indices (mRNAsi) and construct a mRNAsi-related risk model to predict the prognosis of OS. Methods: The one-class logistic regression (OCLR) algorithm was applied to the RNA- sequencing (seq) data of human embryonic stem cells (hESC) and induced pluripotent stem cell (iPSC) lines to calculate mRNAsi. Weighted gene co-expression network analysis (WGCNA) was performed on data obtained from the TARGET database to screen the mRNAsi-related genes. Univariate Cox regression analysis was implemented to screen mRNAsi-related genes with prognostic significance for consensus clustering of OS. The least absolute shrinkage and selection operator (LASSO) and COX regression analysis were conducted to construct a risk model based on mRNAsi-related genes. Results: Six gene modules were identified in the TARGET database. The yellow module showed the strongest negative correlation with mRNAsi and the strongest significant positive correlation with the immune score and stromal score. OS was divided into three molecular subtypes with significant survival differences based on 73 mRNAsi-related genes with prognostic value for OS. The survival rate was ranked as C3 < C1 < C2 from low to high. The levels of immune components in C2 was significantly higher than those in C1 and C3. HSD11B2, GBP1, RNF130, APBB1IP, and NPC2 in the yellow module were used as variables for building the mRNAsi-related risk model. The survival rate of the high-risk group (as defined by this model) was significantly higher than that of the low-risk group, and it had significant survival prediction ability in 28 types of cancer. In addition, the mRNAsi-related risk model was superior to the Tumor Immune Dysfunction and Exclusion (TIDE) model in predicting the prognosis and immunotherapy response in all three immunotherapy cohorts. Conclusions: This study classified OS and constructed a mRNAsi-related risk model based on mRNAsi-related genes, which provides a potential tool for more accurate risk stratification of OS and prediction of immunotherapy response.

Effects of puerarin on the intervertebral disc degeneration and biological characteristics of nucleus pulposus cells.

CONTEXT: Intervertebral disc degeneration (IDD) is the pathological basis of spinal degenerative diseases. Puerarin (PU) is an isoflavonoid with functions and medicinal properties. OBJECTIVE: To explore the effect of PU on IDD and its potential mechanism of action. MATERIALS AND METHODS: Sprague-Dawley (SD) rats were divided into sham, IDD, low PU, and high PU groups. Rat nucleus pulposus cells (NPCs) were isolated and divided into control, IL-1ß, 100 and 200 µmol/mL PU, TAK-242 (TLR4 inhibitor), or 200 µmol/mL PU + LPS (TLR4 activator) groups. The water content, inflammatory factors, proliferation activity, TLR4/NF-κB pathway activity, apoptosis rate, protein expression of apoptosis, and histology of the extracellular matrix (ECM) were analysed. RESULTS: In vivo: Compared with the IDD group, disorganization of intervertebral disc tissue was significantly improved, water content (2.80 ± 0.24 mg, 3.91 ± 0.31 mg vs. 2.02 ± 0.21 mg) and expression levels of collagen II and aggrecan were significantly increased, and the levels of inflammatory factors and the expression levels of TLR4, MyD88, and p-p65 were significantly decreased in IDD rats treated with PU. In vitro: Compared with the IL-1ß group, the proliferation activity of IL-1ß-treated NPCs and the expression of collagen II and aggrecan were significantly increased, while the apoptosis rate, levels of inflammatory factors, and the expression levels of TLR4, MyD88, and p-p65 were significantly decreased in IL-1ß-treated NPCs treated with PU. LPS reversed the biological function changes of IL-1ß-treated NPCs induced by PU. CONCLUSIONS: PU can delay the progression of IDD by inhibiting activation of the TLR4/NF-κB pathway.

Developing a 5-Gene Signature Related to Pyroptosis for Osteosarcoma Patients.

Although the incidence of osteosarcoma (OS) is relatively low compared with other cancer types, the overall survival of metastatic OS was less than 30%. This study aimed to reveal the role of pyroptosis in osteosarcoma and develop a prognostic model related to pyroptosis. Weighted correlation network analysis (WGCNA) was applied to identify key gene modules related to pyroptosis. Univariate Cox regression analysis was used to screen prognostic genes related to pyroptosis. The least absolute shrinkage and selection operator (LASSO) and stepwise Akaike information criterion (stepAIC) were employed to optimize and construct a prognostic model. Five prognostic genes (COL13A1, TNFRSF1A, LILRA6, CTNNBIP1, and CD180) related to pyroptosis were identified. According to the 5-gene signature, OS samples were divided into high- and low-PPRS groups with differential prognosis. Immune-related pathways were more activated in the low-PPRS group. The 5-gene signature was effective and robust to predict OS prognosis. These five prognostic genes were involved in OS development and may serve as new targets for developing therapeutic drugs.

Giant Cell Tumors of Bone in Patients Aged 18 Years Old or Younger: Imaging Features and Tumor Characteristics.

OBJECTIVE: The majority of giant cell tumors of bone (GCTB) occur in adult patients, especially between the ages of 20 and 40. This study aims to investigate the imaging features of GCTBs in pediatric patients and compare their characteristics with adult cases. METHODS: Fifty-seven cases of patients aged 18 years old or younger were retrospectively analyzed, accounting for 12.8% of GCTBs in the First Affiliated Hospital of Zhengzhou University from 2001 to 2019. One hundred twenty-six adult patients (19 years of age and older) with GCTB occurring in long tubular bones were also included in this study. The following clinical information was identified from the medical records: age, sex, and follow-up data. Imaging features were reviewed by two musculoskeletal radiologists. Patient characteristics and imaging features between the two groups were compared. RESULTS: A total of 57 patients (32 females, 25 males) were included in the study. The patients' ages ranged from 9 to 18 (median = 17 y). The majority of tumors occurred in tubular bones (n = 38, 66.7%) and the pelvis (n = 8, 14.0%). Imaging features were identified in GCTB cases occurring in the long tubular bones. Compared with adult GCTB patients, pediatric GCTB patients had a larger superior-inferior (SI) diameter (P = 0.005) and smaller left-to-right diameter/SI diameter ratio (P = 0.001). Epiphyseal involvement was relatively less common in pediatric patients with GCTBs than in adult patients (P = 0.009). The median age of patients without epiphyseal involvement was lower than the median age of patients with epiphyseal involvement (11 vs 17 y). CONCLUSION: GCTB in the pediatric age group is rare. This study has found that, in pediatric patients with GCTBs, the epiphysis is relatively less involved, and the tumor is more likely to grow longitudinally. These findings are helpful in the diagnosis of GCTBs in the pediatric population.

Signature based on metabolic-related gene pairs can predict overall survival of osteosarcoma patients.

BACKGROUND: Osteosarcoma is a tumour of malignant origin in children and adolescents. Recent progression indicates that it is necessary to develop new therapies to improve the patient's prognosis rather than strengthen anti-tumour chemotherapy. Researchers recently realised that cancer is a kind of disease with a metabolic disorder, and metabolic reprogramming is becoming a new cancer hallmark. Hence, our study's primary purpose is to explore the value of genes related to osteosarcoma metabolism. METHODS: From public databases, three osteosarcoma datasets with adequate clinical information were obtained. Besides, the IMvigor dataset through the 'IMvigor' package as a supplement was downloaded, the metabolic-related genes were identified, and these genes were used to construct the metabolic-related gene pairs (MRGP). Based on the prognosis-related MRGP, two molecular subtypes were identified. There are significant differences in the metabolic characteristics between the two molecular subtypes. Subsequently, the MRGP signature is constructed using the least absolute shrinkage and selection operator regression method. Finally, use SubMap analysis to evaluate the response of patients in the MRPG signature group to immunotherapy. RESULTS: The MRGP signature can reliably predict overall survival in patients with osteosarcoma. The MRGP signature is also associated with osteosarcoma patients' metastatic status and can be used for subsequent risk classification of metastatic patients. The immunotherapy is more likely to benefit the patients in the MRGP low-risk group. CONCLUSION: Metabolic-related gene pairs signature can assess the prognosis of patients with osteosarcoma.

A Recurrent Synovial Osteochondromatosis of the Knee: A Case Report.

We report a case of a farmer who presented with synovial osteochondromatosis of his right knee that mimicked a huge hardball. A synovial proliferative disease associated with metaplasia of cartilage resulting in sporadic multiple intra-articular and extra-articular loose bodies. Our focus is to report a rare case successfully operated which has an educational significance in clinical practice.

Construction of immune-related gene pairs signature to predict the overall survival of osteosarcoma patients.

The purpose of this study is to establish the prognosis of osteosarcoma patients based on the characteristics of immune-related gene pairs. We used the lasso Cox regression model to construct and verify the signature consisting of 14 immune-related gene pairs. This signature can accurately predict the overall survival of osteosarcoma patients and is an independent prognostic factor for osteosarcoma patients. For this we constructed a signature-based nomogram. The results of the nomogram show that our signature can bring clinical net benefits. We then assessed the abundance of infiltrating immune cells in each sample, and combine the results of the gene set enrichment analysis of a single sample to explore the differences in the immune microenvironment between IRPG signature groups. The result of gene set enrichment analysis shows the strong relationship between signature and immune system. Finally, we evaluated the relationship between signature and immunotherapy efficiency using algorithms such as TIMI and SubMap to explore patients who might benefit from immunotherapy. In conclusion, our signature can predict the overall survival rate of osteosarcoma patients and provide potential guidance for exploring patients who may benefit from immunotherapy.

Meta-Analysis of Hematological Biomarkers as Reliable Indicators of Soft Tissue Sarcoma Prognosis.

Background: Several recent studies have reported the reliable prognostic effect of hematological biomarkers in various tumors. Yet, the prognostic value of these hematological markers in soft tissue sarcoma (STS) remains inconclusive. Thus, the aim of this meta-analysis was to check the effect of hematological markers on the prognosis of STS. Methods: We systematically searched for relevant papers published before October 2019 in the PubMed and EMBASE databases. Overall survival (OS) and disease-specific survival (DSS) were the primary outcome, whereas disease-free survival was the secondary outcome. A thorough study of hazard ratios (HR) and 95% of confidence intervals (CIs) was done for determining the prognostic significance. Results: We performed 23 studies that comprised of 4,480 patients with STS. The results revealed that higher neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), and platelet-to-lymphocyte ratio (PLR) were associated with poor OS/DFS (HR = 2.08/1.72, for NLR; HR = 1.92/1.75, for CRP, and HR = 1.86/1.61, for PLR). In contrast, a low lymphocyte-to-monocyte ratio (LMR) was relate to worse OS/DFS (HR = 2.01/1.90, for LMR). Moreover, pooled analysis illustrated that elevated NLR and CRP represents poor DSS, with HRs of 1.46 and 2.06, respectively. In addition, combined analysis revealed that higher Glasgow prognostic score (GPS) was linked to an adverse OS/DSS (HR = 2.35/2.77). Conclusion: Our meta-analysis suggested that hematological markers (NLR, CRP, PLR, LMR, and GPS) are one of the important prognostic indicators for patients affected by high-grade STS and patients with the STS being located in the extremity.

Oncolytic adenovirus Ad11 enhances the chemotherapy effect of cisplatin on osteosarcoma cells by inhibiting autophagy.

Targeted oncolytic adenoviruses can selectively replicate in cancer cells; combined with traditional chemotherapy drugs, this approach is expected to become an important treatment method for overcoming the current bottleneck of osteosarcoma treatment. Here, we investigate the effect of oncolytic adenovirus Ad11 combined with cisplatin on autophagy in osteosarcoma cells. Immunohistochemistry was used to detect CD46 expression in patients with osteosarcoma. A cytotoxicity assay was employed to detect the killing effect of Ad11, cisplatin and their combination on osteosarcoma cells under different time scenarios. Expression of autophagy proteins Beclin1, ATG3, and LC3A/B under treatment of osteosarcoma cells with Ad11, cisplatin and their combination under different time scenarios was detected by immunofluorescence and western blotting. We found that the oncolytic adenovirus Ad11 synergizes with cisplatin to kill osteosarcoma cells and that the synergistic effect was greatest when cells were first treated with Ad11. This synergy is due to oncolytic adenovirus Ad11-mediated inhibition of autophagy, which enhanced the sensitivity of cells to chemotherapy. In conclusion, this study provides evidence that the oncolytic adenovirus Ad11 can enhance the effect of chemotherapy by inhibiting autophagy. The findings provide a cytological basis for the treatment of osteosarcoma with oncolytic adenovirus combined with cisplatin.

The efficacy and safety comparison of first-line chemotherapeutic agents (high-dose methotrexate, doxorubicin, cisplatin, and ifosfamide) for osteosarcoma: a network meta-analysis.

BACKGROUND: Osteosarcoma, a primary malignant bone tumor derived from mesenchymal tissue, is the most common type of pleomorphic tumor that occurs in children and adolescents. The aim of this study was to compare the efficacy and safety of high-dose methotrexate (M), doxorubicin (D), cisplatin (C), and ifosfamide (I) in the management of osteosarcoma. METHODS: Electronic databases including PubMed, Cochrane Library, and Embase database were searched for studies published from when the databases were established to July 13, 2019. The network meta-analysis was performed using software R 3.3.2 and STATA version 41.0 after demographic and outcome data extraction. The ranks based on probabilities of interventions for each outcome were performed. In addition, the consistency of direct and indirect evidence was assessed by node splitting. RESULTS: The network meta-analysis results revealed that MDCI had a significant lower hazard risk of overall survival [MDCI vs MDC: HR = 0.74, 95% CrI (0.23, 0.87); MDCI vs DC: HR = 0.60, 95% CrI (0.16, 0.92)]. In addition, MDCI had a clearly longer progression-free survival time than that of DC [MDCI: HR = 0.88, 95% CrI (0.46, 0.98)]. No significant difference was detected in MDC and DC in OS, PFS, and AEs. The probabilities of rank plot showed that MDCI ranked first in OS (73.12%) and PFS (52.43%). DC was the best treatment in safety, ranked first (75.43%). CONCLUSIONS: MDCI showed its superiority among all chemotherapeutic agents in relation to efficacy and safety, followed by MDC. In addition, MDCI was associated with an increased risk of AEs. According to our analysis, DC was less effective but safer for MDC and MDCI.

MACC1 Contributes to the Development of Osteosarcoma Through Regulation of the HGF/c-Met Pathway and Microtubule Stability.

Osteosarcoma (OS) is the most prevalent human bone malignancy, and presents a global annual morbidity of approximately five cases per million. Notably, precise and efficient targeted therapy has become the most promising strategy for the treatment of OS; however, there is still an urgent need for the identification of suitable therapeutic targets. Metastasis-associated in colon cancer 1 (MACC1) was first identified in colon tumors by differential display RT-PCR, and was shown to be involved in the regulation of colon tumor growth and metastasis through the hepatocyte growth factor (HGF)/c-Met signaling pathway. Additionally, MACC1 overexpression has been reported to induce the growth of several types of cancers, including glioblastoma multiforme and gastric cancer. However, whether MACC1 also plays a role in the progression of OS remains unclear. In this study, we found that MACC1 was highly expressed in human OS tissues, as well as in U-2OS and MG-63 cells, when compared with normal tissues and osteoblasts, respectively. Our data further indicated that MACC1 expression was correlated with several clinicopathological features of OS. Through in vitro assays, we found that MACC1 depletion markedly suppressed the proliferative ability of both OS cells and endothelial cells, and inhibited the angiogenic capacity of endothelial cells. Similarly, MACC1 depletion inhibited tumor growth, metastasis, and angiogenesis in mice. Mechanistically, we found that MACC1 could bind to the MET promoter, and enhanced the proliferation of both OS cells and endothelial cells through the HGF/c-Met signaling pathway. Furthermore, we show that MACC1 also promoted angiogenesis by regulating microtubule dynamics, thereby promoting the progression of OS. Our results indicate that MACC1 may be a new and promising therapeutic target for the treatment of OS.

Inhibitory effects of indirubin-3'-monoxime against human osteosarcoma.

Indirubin is widely used as the active component of "Dangui Luhui Wan" in ancient China. However, its effects against the osteosarcoma (OS), the most common primary malignancy, are still unknown. In our present study, we investigated the effects of the Indirubin-3'-monoxime (I3M), a derivative of indirubin with better water solubility, against the OS cells. We found I3M inhibited OS cell proliferation in a dose-dependent manner. Flow cytometry assays showed that I3M could not only induce OS cell apoptosis in a time- and dose-dependent manner but also regulate the cell cycle distribution. Additionally, we demonstrated that several Bcl-2 family members, cyclin-dependent kinases (CDKs) and cyclins contributed to this process. Furthermore, out data verified that I3M suppressed OS cell migration and invasion by decreasing MMP-2 and MMP-9 levels. Moreover, survivin and focal adhesion kinase (FAK) might play important roles in the anti-OS effects of I3M. The administration of I3M also inhibited the OS cell growth in mice. Taken together, our results indicated the inhibitory effects of I3M against human OS and thus might be an efficient candidate for OS chemotherapy.

PDCD5 inhibits osteosarcoma cell metastasis via targeting TGF-ß1/Smad signaling pathway and is associated with good prognosis.

Whether programmed cell death 5 (PDCD5) is effective for tumor metastasis remains unclear. In this study, the expression of PDCD5 in 63 osteosarcoma (OS) tissues and two OS cell lines was analyzed. Then the relationship between PDCD5 expression and clinicopathological features of OS was studied. In addition, adhesion, wound healing, Transwell and Matrigel tube formation assays were used to explore the role of PDCD5 in OS cell adhesion, migration, invasion and angiogenesis. Western blotting was used to detect the protein expression of TGF-ß1/Smad signaling pathway and epithelial-mesenchymal transition (EMT)-related markers. At the same time, key molecules involved in migration, invasion and EMT in tumor specimens were assessed by immunohistochemistry. The data showed that PDCD5 overexpression significantly attenuated OS cell adhesion, migration, invasion and angiogenesis. Furthermore, PDCD5 knockdown caused an opposite effect on these phenotypes in vitro. PDCD5 inhibited tumor metastasis by attenuating EMT in OS cells. PDCD5 knockdown enhanced the incidence of metastasis and EMT in OS cells. Furthermore, PDCD5 expression was reduced by transforming growth factor-ß1 (TGF-ß1) in a time-dependent manner, and TGF-ß1-induced EMT was induced by PDCD5 knockdown. Inactivation of the TGF-ß1/Smad signaling pathway was involved in the anti-tumor function of PDCD5 in OS. Furthermore, tumor progression in OS patients was associated with low expression of PDCD5, indicating a decrease in survival and a poor prognosis. Our results suggest that PDCD5 may attenuate EMT by inhibiting TGF-ß1/Smad signaling pathway to inhibit OS metastasis and may be a potential adjuvant genetic therapy for OS.

[Preliminary study on surgical treatment of Erdheim-Chester disease].

Objective: To summarize the preliminary effectiveness of surgical treatment of Erdheim-Chester disease (ECD), so as to improve the understanding of the disease by orthopedic surgeons. Methods: The clinical data of 9 patients with ECD between December 2012 and October 2017 were retrospectively analysed. There were 6 males and 3 females with an median age of 42 years (range, 8-61 years). The disease duration was 4-59 months (mean, 39 months). There were 2 cases of multiple lesions, including 1 case involving soft tissue of the buttocks and bilateral tibia, 1 case involving the sinus, skull base, and proximal right tibia; 7 cases with single lesion, including 3 cases of right femoral neck, 1 case of proximal right tibia, 1 case of right humerus, and 2 cases of ribs. Nine patients were diagnosed according to clinical manifestations, imaging examination, and pathological diagnosis. Four patients underwent needle biopsy before operation and 5 patients were diagnosed by postoperative pathology examination. Five cases underwent lesional scraping and internal fixation, 1 case underwent bone scraping and bone grafting, and 3 cases underwent lesion resection. One of the multiple lesions was treated with interferon and hormone. Results: Nine patients underwent the surgery safely. There was no fever, wound exudation, infection, etc., and the incisions healed by first intention. All the patients were followed up 4-59 months with an average of 31.4 months. One patient with bilateral tibia and hip soft tissue involvement continued to receive medical treatment, and the tumor was controlled without significant increasing. The remaining 8 patients were examined for X-ray films at 3, 6, and 12 months after surgery, the bone has been fused and the steel plate and intramedullary nail were firmly fixed, and no tumor recurrence was observed. At 1 year after surgery, the pain symptoms of the patients improved and returned to normal life; 3 of them who involving the right femoral neck walked freely, and the quality of life improved significantly. Conclusion: ECD patients can achieve the purpose of eliminating lesions and relieving pain after surgical treatment, and the surgical treatment has the advantages of quick relief of pain, improved quality of life, small side effects, and low economic cost when compared with medical treatment.

Intramedullary Nailing Combined with Bone Grafting for Benign Lesions of the Proximal Femur.

OBJECTIVE: To evaluate the effectiveness of intramedullary nailing for benign lesions of the proximal femur. METHOD: A retrospective analysis was carried out on 68 cases of benign lesions in the proximal femur at our hospital from April 2002 to April 2013 (38 men and 30 women). Mean age at surgery was 35.5 years (range, 22-56 years). The cases were divided into two groups: curettage of the lesion with bone grafting only as the grafting group (32 cases) and internal fixation after removal of the lesion as the fixation group (36 cases). For the grafting group, lesions were scraped out, deactivated and washed thoroughly with normal saline, then the allogeneic bone was implanted. For the fixation group, after the lesions were scraped, the intramedullary nails were implanted, and allogeneic bone was implanted into the scraped cavity with compaction. RESULTS: Pathological examination showed that 24 out of 68 cases (35.3%) had simple bone cysts (suffered from pathological fracture in 2 cases); 21 (30.9%) fibrous dysplasia; 18 (26.5%) aneurysmal bone cysts; 3 (4.4%) chondroblastoma, 2 (2.9%) out of which were combined with aneurysmal bone cysts. All patients were followed up for 12-96 months (56 months for mean). In the grafting group, 4 patients had postoperative complications (1 pathological bone fractures and 3 deep vein thrombosis), but only 1 patient of the fixation group (deep vein thrombosis) (P < 0.05). The average bedridden time after surgery was 11.4 ± 7.6 days for the grafting group, and for the other group was 7.5 ± 5.4 days ( P < 0.05). CONCLUSION: Both treatments are effective for benign lesions in the proximal femur, but the fixation group facilitated the functional recovery of patients and reduced postoperative complications.

Sternal tumor resection and reconstruction with titanium mesh: a preliminary study.

OBJECTIVE: To explore the clinical efficacy and complications of treating sternal tumors by resection and titanium mesh thoracic reconstruction. METHODS: This retrospective analysis of eight patients with sternal tumors treated in the Department of Orthopedic Surgery at the First Affiliated Hospital of Zhengzhou University from January 2008 to June 2012 included five men and three women aged 37-66 years (mean, 50.4 years). The histological diagnoses were chondrosarcoma (two cases), osteosarcoma (one), malignant fibrous histiocytoma (two), eosinophilic granuloma (one) and sternal metastasis from breast cancer (two). The tumors were invading the manubrium sterni (three cases), manubrium sterni and body (three) and sternal body (two). All patients underwent needle or incisional biopsy prior to sternal tumor resection and titanium mesh thoracic reconstruction. RESULTS: All patients were followed for 9 months to 4 years. There were no intraoperative complications or operative or postoperative deaths. One patient developed a deep wound hematoma 1 week postoperatively; incisional drainage and debridement resulting in healing within 2 weeks. There was no loosening or exsertion of the titanium mesh and no patients developed respiratory complications or thoracic deformity. One patient with malignant fibrous histiocytoma died of lung metastases 9 months postoperatively, another with malignant fibrous histiocytoma died of liver metastases 14 months postoperatively; the remaining patients survived without tumor recurrence. CONCLUSION: Titanium mesh chest reconstruction after sternal tumor resection has the advantages of simplifying the procedure, achieving a good shape and having few complications. Titanium mesh is an ideal material for reconstruction of the sternum.

Bortezomib induces apoptosis and autophagy in osteosarcoma cells through mitogen-activated protein kinase pathway in vitro.

OBJECTIVE: To investigate the effects of bortezomib on human osteosarcoma cells from the HOS cell line, and the underlying associated mechanisms. METHODS: Viability of HOS cells treated with bortezomib (5-20 nM) for different time periods was measured and changes in the cell cycle were assessed. Apoptosis and autophagy in HOS cells treated with bortezomib were analysed using annexin V-fluorescein isothiocyanate assay, transmission electron microscopy and Western blotting. Surges in mitogen-activated protein kinase (MAPK) pathways including MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK1/2), ERK1/2, c-Jun N-terminal kinase (JNK) and p38 MAPK were analysed using Western blotting. RESULTS: Bortezomib induced growth inhibition in a time- and dose-dependent manner, and autophagy and apoptosis in a dose-dependent manner, in HOS cells. HOS cell autophagy and apoptosis in response to bortezomib, corresponded with changing levels of intracellular MAPK signalling molecules. CONCLUSIONS: This study provided new insights into the mechanisms underlying bortezomib-induced apoptosis in human osteosarcoma HOS cells, and suggests that bortezomib could be a potent chemotherapeutic agent in the treatment of osteosarcoma.

Differential expression of the RANKL/RANK/OPG system is associated with bone metastasis in human non-small cell lung cancer.

BACKGROUND: Human non-small cell lung cancer (NSCLC) patients exhibit a high propensity to develop skeletal metastasis, resulting in excessive osteolytic activity. The RANKL/RANK/OPG system, which plays a pivotal role in bone remodeling by regulating osteoclast formation and activity, is of potential interest in this context. MATERIALS AND METHODS: Reverse transcriptase polymerase chain reaction, western blotting, and immunohistochemical analysis were used to examine the expression of RANKL, RANK, and OPG in human NSCLC cell lines with different metastatic potentials, as well as in 52 primary NSCLC samples and 75 NSCLC bone metastasis samples. In primary NSCLC patients, the expression of these proteins was correlated with clinicopathological parameters. Recombinant human RANKL and transfected RANKL cDNA were added to the PAa cell line to evaluate the promoter action of RANKL during the process of metastasis in vitro and in vivo. RESULTS: Up-regulated RANKL, RANK, and OPG expression and increased RANKL:OPG ratio were detected in NSCLC cell lines and in tumor tissues with bone metastasis, and were correlated with higher metastatic potential. The metastatic potential of NSCLC in vitro and in vivo, including migration and invasion ability, was significantly enhanced by recombinant human RANKL and the transfection of RANKL cDNA, and was impaired after OPG was added. The increased expression of RANKL and OPG correlated with tumor stage, lymph node metastasis, and distant metastasis. CONCLUSIONS: Differential expression of RANKL, RANK, and OPG is associated with the metastatic potential of human NSCLC to skeleton, raising the possibility that the RANKL/RANK/OPG system could be a therapeutic target for the treatment of metastatic NSCLC patients.

Arsenic trioxide inhibits Ewing's sarcoma cell invasiveness by targeting p38(MAPK) and c-Jun N-terminal kinase.

Ewing's sarcoma is the second most frequent primary malignant bone tumor, mainly affecting children and young adults. The notorious metastatic capability of this tumor aggravates patient mortality and remains a problem to be overcome. We investigated the effect of arsenic trioxide (As2O3) on the metastasis capability of Ewing's sarcoma cells. We performed 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide assays to choose appropriate concentrations of As2O3 for the experiments. Migration, invasion, and adhesion assays were performed to assess the effect of As2O3 on the metastasis of Ewing's sarcoma. Immunofluorescent staining was used to observe cytoskeleton reorganization in Ewing's sarcoma cells treated with As2O3. Changes in matrix metalloproteinase-9 expression and the mitogen-activated protein kinase (MAPK) pathway were investigated using western blot. Inhibitors of p38(MAPK) (sb202190) and c-Jun NH2-terminal kinase (JNK, sp600125) were used in invasion assays to determine the effect of p38(MAPK) and JNK. We found that As2O3 may markedly inhibit the migration and invasion capacity of Ewing's sarcoma cells with structural rearrangements of the actin cytoskeleton. The expressions of matrix metalloproteinase-9, phosphor-p38(MAPK), and phosphor-JNK were suppressed by As2O3 treatment in a dose-dependent manner. The inhibitors of p38(MAPK) (sb202190) and JNK (sp600125) enhanced the inhibition induced by As2O3, which was counteracted by anisomycin, an activating agent of p38(MAPK) and JNK. Taken together, our results demonstrate that As2O3 can inhibit the metastasis capability of RD-ES and A-673 cells and may have new therapeutic value for Ewing's sarcoma.