Expression of molecular markers in the tumor and survival prognosis in osteosarcoma

Molecular Analysis of the Superior Efficacy of a Dual Epidermal Growth Factor Receptor (EGFR)-DNA-Targeting Combi-Molecule in Comparison with Its Putative Prodrugs 6-Mono-Alkylamino- and 6,6-Dialkylaminoquinazoline in a Human Osteosarcoma Xenograft Model

Background: ZR2002 is a dual EGFR-DNA-targeting combi-molecule that carries a chloroethyl group at the six-position of the quinazoline ring designed to alkylate DNA. Despite its good pharmacokinetics, ZR2002 is metabolized in vivo into dechlorinated metabolites, losing the DNA-alkylating function required to damage DNA. To increase the DNA damage activity in tumor cells in vivo, we compared ZR2002 with two of its 6-N,N-disubstituted analogs: "JS61", with a nitrogen mustard function at the six-position of the quinazoline ring, and "JS84", with an N-methyl group. Methods: Tumor xenografts were performed with the human Saos-2 osteosarcoma cell line expressing EGFR. Mice were treated with ZR2002, JS84 or JS61, and the tumor burden was measured with a caliper and CT/PET imaging. Drug metabolism was analyzed with LC-MS. EGFR and ɣ-H2AX phosphorylation were quantified via Western blot analysis and immunohistochemistry. Results: In vivo analysis showed that significant tumor growth inhibition was only achieved when ZR2002 was administered in its naked form. The metabolic dealkylation of JS61 and JS84 did not release sufficient concentrations of ZR2002 for the intratumoral inhibition of P-EGFR or enhanced levels of P-H2AX. Conclusions: The results in toto suggest that intratumoral concentrations of intact ZR2002 are correlated with the highest inhibition of P-EGFR and induction of DNA damage in vivo. ZR2002 may well represent a good drug candidate for the treatment of EGFR-expressing osteosarcoma.

A Multiparametric Method Based on Clinical and CT-Based Radiomics to Predict the Expression of p53 and VEGF in Patients With Spinal Giant Cell Tumor of Bone

Purpose

This project aimed to assess the significance of vascular endothelial growth factor (VEGF) and p53 for predicting progression-free survival (PFS) in patients with spinal giant cell tumor of bone (GCTB) and to construct models for predicting these two biomarkers based on clinical and computer tomography (CT) radiomics to identify high-risk patients for improving treatment.

Material and Methods

A retrospective study was performed from April 2009 to January 2019. A total of 80 patients with spinal GCTB who underwent surgery in our institution were identified. VEGF and p53 expression and clinical and general imaging information were collected. Multivariate Cox regression models were used to verify the prognostic factors. The radiomics features were extracted from the regions of interest (ROIs) in preoperative CT, and then important features were selected by the SVM to build classification models, evaluated by 10-fold crossvalidation. The clinical variables were processed using the same method to build a conventional model for comparison.

Results

The immunohistochemistry of 80 patients was obtained: 49 with high-VEGF and 31 with low-VEGF, 68 with wild-type p53, and 12 with mutant p53. p53 and VEGF were independent prognostic factors affecting PFS found in multivariate Cox regression analysis. For VEGF, the Spinal Instability Neoplastic Score (SINS) was greater in the high than low groups, p < 0.001. For p53, SINS (p = 0.030) and Enneking stage (p = 0.017) were higher in mutant than wild-type groups. The VEGF radiomics model built using 3 features achieved an area under the curve (AUC) of 0.88, and the p53 radiomics model built using 4 features had an AUC of 0.79. The conventional model built using SINS, and the Enneking stage had a slightly lower AUC of 0.81 for VEGF and 0.72 for p53.

Conclusion

p53 and VEGF are associated with prognosis in patients with spinal GCTB, and the radiomics analysis based on preoperative CT provides a feasible method for the evaluation of these two biomarkers, which may aid in choosing better management strategies.

Introducing Fluorescence-Guided Surgery for Pediatric Ewing, Osteo-, and Rhabdomyosarcomas: A Literature Review

Sarcomas are a rare heterogeneous group of malignant neoplasms of mesenchymal origin which represent approximately 13% of all cancers in pediatric patients. The most prevalent pediatric bone sarcomas are osteosarcoma (OS) and Ewing sarcoma (ES). Rhabdomyosarcoma (RMS) is the most frequently occurring pediatric soft tissue sarcoma. The median age of OS and ES is approximately 17 years, so this disease is also commonly seen in adults while non-pleiomorphic RMS is rare in the adult population. The mainstay of all treatment regimens is multimodal treatment containing chemotherapy, surgical resection, and sometimes (neo)adjuvant radiotherapy. A clear resection margin improves both local control and overall survival and should be the goal during surgery with a curative intent. Real-time intraoperative fluorescence-guided imaging could facilitate complete resections by visualizing tumor tissue during surgery. This review evaluates whether non-targeted and targeted fluorescence-guided surgery (FGS) could be beneficial for pediatric OS, ES, and RMS patients. Necessities for clinical implementation, current literature, and the positive as well as negative aspects of non-targeted FGS using the NIR dye Indocyanine Green (ICG) were evaluated. In addition, we provide an overview of targets that could potentially be used for FGS in OS, ES, and RMS. Then, due to the time- and cost-efficient translational perspective, we elaborate on the use of antibody-based tracers as well as their disadvantages and alternatives. Finally, we conclude with recommendations for the experiments needed before FGS can be implemented for pediatric OS, ES, and RMS patients.

Identification of Abnormal Spindle Microtubule Assembly as a Promising Therapeutic Target for Osteosarcoma

Objective

To demonstrate the expression of abnormal spindle microtubule assembly (ASPM) in clinical osteosarcoma tissue specimens collected in our hospital, and to explore the function of ASPM in osteosarcoma in vitro and in vivo.

Methods

Tissue specimens from 82 cases of osteosarcoma were collected and analyzed by immunohistochemistry assay. We also investigated the relationship between ASPM expression and clinicopathological characteristics in the patients. We transfected shASPM plasmid and the empty control plasmid, respectively, and then used quantitative polymerase chain reaction and western blot analysis to detect ASPM expression. Cell colony assay and MTT were used to observe the proliferation ability. In vivo study was undertaken to explore the ASPM function further.

Results

In this study, ASPM showed high expression in osteosarcoma tissue samples compared with non‐tumor normal tissues. ASPM was positively correlated with clinical pathological characteristics, including tumor size (P = 0.024) and clinical stage (P = 0.045). Our results further showed that ASPM depletion dramatically inhibited the proliferation of osteosarcoma cells (with fewer cells in the sh‐RNA‐ASPM group compared with the control group(P < 0.05, respectively), and the in vivo assays further confirmed that ASPM ablation markedly blocked tumor growth compared with control (P < 0.05).

Conclusion

Our data provides strong evidence that the high expression of ASPM in osteosarcoma promotes proliferation in vitro and in vivo, indicating its potential role as an osteosarcoma therapeutic target.

APLNR promotes the progression of osteosarcoma by stimulating cell proliferation and invasion

Osteosarcoma is the most common type of bone malignancies with a poor prognosis. In recent years, targeted therapy has shown great potential in the treatment of osteosarcoma, and more effective therapeutic targets for this disease need to be developed. APLNR is a seven transmembrane G-protein-coupled receptor expressed widely in multiple tissues. As has been reported, APLNR is involved in various physiological and pathological processes. Although APLNR plays a role in the development and progression of multiple tumors, the potential role of APLNR in osteosarcoma, a highly malignant tumor, remains unclear. Here, we reported that APLNR expression was correlated positively with clinical features including tumor size and stage of osteosarcoma. We found that APLNR knockdown inhibited the proliferation and invasion of osteosarcoma cells in vitro. In addition, APLNR could promote the progression and metastasis of osteosarcoma in mice. Collectively, this study showed the potential link between APLNR and osteosarcoma and suggested APLNR as a novel therapeutic target for osteosarcoma.

Cyclooxygenase-2 expression correlates with development, progression, metastasis, and prognosis of osteosarcoma: a meta-analysis and trial sequential analysis

Cyclooxygenase‐2 (COX‐2), a key enzyme in arachidonic acid metabolism, is involved in several cancers, including osteosarcoma. The prognostic significance of COX‐2 in osteosarcoma remains controversial. This study was to analyze the potential clinical and prognostic effects of COX‐2 protein expression in patients with osteosarcoma. Eligible articles were searched via online databases. The combined odds ratios (ORs) or hazard ratios (HRs) with their 95% confidence intervals (95% CIs) were calculated using the random‐effects model. Trial sequential analysis (TSA) was applied to analyze the required information size and determine the reliability of the evidence. Twenty‐three studies on COX‐2 expression were identified, which included a total of 1084 patients with malignant osteosarcoma and 247 patients with benign osteochondroma. COX‐2 protein expression in osteosarcoma was higher than in benign osteochondroma (OR = 7.66, P < 0.001). COX‐2 expression was not correlated with age, gender, tumor location, cancer histology, or necrosis (P > 0.1), but was significantly associated with tumor grade (high grade vs. low grade: OR = 4.81, P < 0.001), clinical stage (stage 3–4 vs. stage 1–2: OR = 4.89, P < 0.001), and metastasis (yes vs. no: OR = 3.53, P < 0.001). Based on TSA results, we suggest that additional studies are not required to examine osteosarcoma vs. benign osteochondroma, tumor grade, clinical stage, or metastasis. No heterogeneity was observed in these analyses. COX‐2 expression is linked to poor prognosis in metastasis‐free survival, overall survival, and relapse‐free survival, as indicated by multivariate analysis. Therefore, the expression of COX‐2 may correlate with the development, progression, metastasis, and poor prognosis of osteosarcoma.

MicroRNA‑509 acts as a tumor suppressor in tongue squamous cell carcinoma by targeting epidermal growth factor receptor

Tongue squamous cell carcinoma (TSCC) is the most frequent type of oral carcinoma, and is characterized by high metastatic and growth capabilities. Previous studies have demonstrated that aberrantly expressed cancer‑associated microRNAs (miRs) may be associated with tumorigenesis and tumor development in various types of cancer, including TSCC. miR‑509 has been identified as a critical regulator in tumorigenesis and tumor development, via its tumor‑suppressing actions in several types of human cancer. In the present study, miR‑509 expression in TSCC tissues and cell lines was determined by reverse transcription‑quantitative polymerase chain reaction. The effects of miR‑509 on TSCC cell proliferation and invasion were evaluated via MTT and invasion assays, respectively. In addition, the direct target of miR‑509 in TSCC was investigated. The present study demonstrated that miR‑509 expression was downregulated in TSCC tissue samples and cell lines, whereas its ectopic expression suppressed TSCC cell proliferation and invasion in vitro. In addition, epidermal growth factor receptor (EGFR) was identified as a direct target gene of miR‑509 in TSCC cells. EGFR downregulation was demonstrated to suppress the proliferation and invasion of TSCC cells, similar to miR‑509 overexpression. Furthermore, EGFR was significantly upregulated in TSCC tissues, and the levels of miR‑509 were revealed to be negatively correlated with EGFR expression in TSCC tissues. Following transfection with miR‑509 mimics, signaling pathways downstream of EGFR appeared to be suppressed, as phosphorylated (p)‑extracellular signal‑regulated kinase and p‑Akt were downregulated in TSCC cells. In conclusion, the results of the present study suggested that miR‑509 may inhibit the proliferation and invasion of TSCC cells via directly targeting EGFR, thus suggesting that the miR‑509/EGFR axis may have potential as a novel therapeutic target for the development of a treatment for patients with TSCC.

Molecular Markers in Bone and Soft-Tissue Tumors

Many sarcomas such as osteosarcoma have complex molecular compositions and behaviors that make standardized treatment difficult for patients with these tumors. Chromosomal translocations are noted in specific bone and soft-tissue sarcomas, and there are molecular tests (polymerase chain reaction [PCR] and fluorescence in situ hybridization [FISH]) used for accurate diagnosis. The translocations noted in sarcomas may allow future therapeutic targeting.

HER-2 expression in biopsy and surgical specimen on prognosis of osteosarcoma: A systematic review and meta-analysis of 16 studies

Numerous original clinical studies have attempted to investigate the prognostic value of HER-2 overexpression in osteosarcoma, but the results of these studies are not consistent. This meta-analysis and systematic review was performed to further assess the correlation between HER-2 expression and prognosis in patients with osteosarcoma. A detailed search of relevant publications was conducted using 7 electronic databases: PubMed, Embase, the Cochrane library, the Wanfang database, the China National Knowledge Internet (CNKI) database, the Chinese VIP database, and the Chinese Biological Medical (CBM) Database for publications through August 1, 2015, using the following keywords (HER-2 OR ErbB-2 OR C-erbB-2 OR neu) AND (osteosarcoma OR osteogenic tumor). The bibliographies of potentially relevant articles and identified articles were then searched by hand. Eligible studies were those that enrolled participants with osteosarcoma and provided survival outcome in HER-2 positive and negative groups. The hazard ratio (HR) and 95% confidence interval (CI) for each individual study was calculated and pooled to obtain integrated estimates, using random effects modeling. Sixteen studies involving 934 participants with osteosarcoma met our inclusion criteria. HER-2 overexpression was documented in 42.2% of patients with osteosarcoma. Compared with patients without HER-2 overexpression, those overexpressing HER-2 had decreased overall survival (HR = 2.03, 95% CI: 1.36-3.03, P < 0.001). Statistical associations between HER-2 overexpression and unfavorable overall survival (OS) were observed for both biopsy and surgical removal specimens (HR = 2.07, 95%CI: 1.16-3.72, P = 0.014; and HR = 2.02, 95%CI: 1.10-3.71, P = 0.024). Results for disease-free survival (DFS) were similar. Overexpression of HER-2 is significantly associated with poor outcome for patients with osteosarcoma and should be assessed at diagnosis and after surgery as a prognostic factor. However, larger-scale multicenter clinical studies are needed to further support these findings.

TP53 Mutations and Survival in Osteosarcoma Patients: A Meta-Analysis of Published Data

Several research groups have examined the association between TP53 mutations and prognosis in human osteosarcoma. However, the results were controversial. The purpose of this study was to evaluate the prognostic value of TP53 mutations in osteosarcoma patients. A meta-analysis was conducted with all eligible studies which quantitatively evaluated the relationship between TP53 mutations and clinical outcome of osteosarcoma patients. Eight studies with a total of 210 patients with osteosarcoma were included in this meta-analysis. The risk ratio (RR) with a 95% confidence interval (95% CI) was calculated to assess the effect of TP53 mutations on 2-year overall survival. The quantitative synthesis of 8 published studies showed that TP53 mutations were associated with 2-year overall survival in osteosarcoma patients. These data suggested that TP53 mutations had an unfavorable impact on 2-year overall survival when compared to the counterparts with wild type (WT) TP53 (RR: 1.79; 95% CI: 1.12 to 2.84; P = 0.01; I (2) = 0%). There was no between-study heterogeneity. TP53 mutations are an effective prognostic marker for survival of patients with osteosarcoma. However, further large-scale prospective trials should be performed to clarify the prognostic value of TP53 mutations on 3- or 5-year survival in osteosarcoma patients.

Analysis of gene expression in cyclooxygenase-2-overexpressed human osteosarcoma cell lines

Osteosarcoma is the most common primary bone tumor, generally affecting young people. While the etiology of osteosarcoma has been largely unknown, recent studies have suggested that cyclooxygenase-2 (COX-2) plays a critical role in the proliferation, migration, and invasion of osteosarcoma cells. To understand the mechanism of action of COX-2 in the pathogenesis of osteosarcoma, we compared gene expression patterns between three stable COX-2-overexpressing cell lines and three control cell lines derived from U2OS human osteosarcoma cells. The data showed that 56 genes were upregulated, whereas 20 genes were downregulated, in COX-2-overexpressed cell lines, with an average fold-change > 1.5. Among the upregulated genes, COL1A1, COL5A2, FBN1, HOXD10, RUNX2, and TRAPPC2are involved in bone and skeletal system development, while DDR2, RAC2, RUNX2, and TSPAN31are involved in the positive regulation of cell proliferation. Among the downregulated genes, HIST1H1D, HIST1H2AI, HIST1H3H, and HIST1H4C are involved in nucleosome assembly and DNA packaging. These results may provide useful information to elucidate the molecular mechanism of the COX-2-mediated malignant phenotype in osteosarcoma.

Effect of c-erbB2 overexpression on prognosis in osteosarcoma: evidence from eight studies

C-erbB2 (HER-2/neu) plays an important role in the progression of several types of cancer by increasing tumor growth, migration, invasion, and metastasis and is associated with poor disease prognosis. Numerous studies examining the relationship between c-erbB2 expression and prognostic impact in patients with osteosarcoma have yielded inconclusive results. We therefore conducted a meta-analysis to provide a comprehensive evaluation of the prognostic role of c-erbB2 expression on 5-year survival, which compared the positive and negative expression of c-erbB2 in patients of the available studies. A detailed search was made in PubMed for relevant original articles published in English. Finally, a total of eight studies with 411 osteosarcoma patients were involved to estimate the relationship between c-erbB2 expression and 5-year overall survival. Positive expressions of c-erbB2 predicted poorer survival in osteosarcoma with the pooled RR of 1.53 (95 % CI 1.20-1.94, P = 0.0006). In conclusion, the findings from this present meta-analysis suggest that c-erbB2 overexpression is related to poor prognostic of osteosarcoma and can be a useful clinical prognostic factor for those patients.

Overexpression of cyclooxygenase-2 in malignant peripheral nerve sheath tumor and selective cyclooxygenase-2 inhibitor-induced apoptosis by activating caspases in human malignant peripheral nerve sheath tumor cells

Background

Cyclooxygenase-2 (COX-2) is a key enzyme in the conversion of arachidonic acid to prostanoids, and its activation is associated with carcinogenesis as well as inflammation. The antitumor effect of selective COX-2 inhibitors has been noted in various malignancies. Malignant peripheral nerve sheath tumor (MPNST) is a rare and aggressive soft tissue sarcoma for which effective treatments have not yet been established. The purpose of this study was to investigate a potential therapeutic role of COX-2 in MPNST.

Methods

We evaluated the expression of COX-2 in 44 cases of high-grade MPNST using immunohistochemical staining and compared the staining results with the characteristics and outcome of the patients. We also investigated the antitumor effect of etodolac, a selective COX-2 inhibitor, on MPNST cells in vitro using the MPNST cell line, FMS-1.

Results

Overexpression of COX-2 (≥50% positive cells) was observed in 29 cases (65.9%), was significantly associated with a poor overall survival (P = 0.0495), and was considered an independent risk factor for a poor outcome by the results of both univariate and multivariate analysis. Etodolac induced apoptosis of FMS-1 cells through the activation of caspase-8, -9, and -3. Moreover, several caspase inhibitors significantly inhibited etodolac-induced apoptosis.

Conclusions

Selective COX-2 inhibitors including etodolac had an antitumor effect on MPNST cells, and their use holds promise as a novel therapeutic strategy for patients with MPNST to improve their prognoses.

Quantitative assessment of the association of COX-2 (Cyclooxygenase-2) immunoexpression with prognosis in human osteosarcoma: a meta-analysis

Background

Numerous studies examining the relationship between Cyclooxygenase-2 (COX-2) immunoexpression and clinical outcome in osteosarcoma patients have yielded inconclusive results.

Methods

We accordingly conducted a meta-analysis of 9 studies (442 patients) that evaluated the correlation between COX-2 immunoexpression and clinical prognosis (death). Pooled odds ratios (OR) and risk ratios (RR) with 95% confidence intervals (95% CI) were calculated using the random-effects or fixed-effects model.

Results

Meta–analysis showed no significant association between COX-2 positivity and age, gender, tumor location, histology, stage, metastasis or 90% necrosis. Conversely, COX-2 immunoexpression was associated with overall survival rate (RR=2.12; 95% CI: 1.10–3.74; P=0.009) and disease-free survival rate (RR=1.63; 95% CI: 1.17–2.28; P=0.004) at 2 years. Sensitivity analysis performed by omitting low quality studies showed that the pooled results were stable.

Conclusions

COX-2 positivity was associated with a lower 2-year overall survival rate and disease-free survival rate. COX-2 expression change is an independent prognostic factor in patients with osteosarcoma.

A systematic review of p53 as a biomarker of survival in patients with osteosarcoma

Osteosarcoma is the most common malignant bone tumor, and the prognosis of patients with osteosarcoma is still unsatisfactory with low survival rates. There are many studies assessing the prognostic role of upregulated p53 in patients presenting osteosarcoma, and there is no consistent finding. To summarize the existing evidence about whether the presence of upregulated p53 was a biomarker of survival in patients with osteosarcoma, we performed a systematic review and meta-analysis of relevant publications. We assessed the effect of upregulated p53 on the 3-year overall survival and the 3-year disease-free survival by calculating the pooled odds ratio (OR) with corresponding 95% confidence interval (95%CI). Fifteen studies with a total of 609 patients with osteosarcoma were finally included into the systematic review and meta-analysis. Compared with osteosarcoma patients with low or undetectable p53, patients with upregulated p53 were obviously associated with decreased 3-year overall survival (OR = 0.29, 95 %CI 0.19-0.43, P < 0.001). In addition, patients with upregulated p53 were obviously associated with decreased 3-year disease-free survival (OR = 0.06, 95 %CI 0.02-0.23, P < 0.001). The results from the systematic review and meta-analysis highlight that p53 is an effective biomarker of survival in patients with osteosarcoma. In addition, more studies with a large sample size are needed to identify the effect of p53 expression in osteosarcoma patients.

Prognostic significance of VEGF expression in osteosarcoma: a meta-analysis

Vascular endothelial growth factor (VEGF) is considered as a prime mediator of angiogenesis and has been implicated in carcinogenesis and metastasis. Various studies examined the relationship between VEGF overexpression with the clinical outcome in patients with osteosarcoma but yielded conflicting results. Electronic databases updated to April 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between VEGF overexpression and survival of patients with osteosarcoma. Survival data were aggregated and quantitatively analyzed. We performed a meta-analysis of eight studies that evaluated the correlation between VEGF overexpression and survival in patients with osteosarcoma. Combined hazard ratios suggested that VEGF overexpression had an unfavorable impact on overall survival (hazard ratio (HR) = 1.75, 95% confidence interval (CI): 1.21-2.28) in patients with osteosarcoma for overall populations, 2.37 (1.35-3.39) in Asian studies but not in non-Asian studies (HR = 1.51, 95% CI: 0.89-2.14). No significant heterogeneity was observed among all studies. VEGF overexpression indicates a poor prognosis for patients with osteosarcoma. However, the prognostic value of VEGF on survival in osteosarcoma patients still needs further large-scale prospective trials to be clarified.

Prognostic significance of cyclooxygenase-2 in osteosarcoma: a meta-analysis

Published studies researching the prognostic significance of cyclooxygenase-2 (COX-2) expression in patients with osteosarcoma are inconclusive and heterogeneous. We conducted a meta-analysis to assess its prognostic value more precisely. The pooled odds ratios (ORs) or hazard ratios (HRs) with corresponding 95 % confidence intervals (CIs) were calculated to evaluate the effects. Fourteen studies with 735 osteosarcoma patients were included to estimate the relationship between COX-2 and metastasis of tumor, clinical stage, and 3-year overall survival. High expressions of COX-2 predicted neoplasm metastasis (OR = 1.891, 95 % CI 1.276-2.803, P = 0.002), advanced clinical stage (OR = 1.801, 95 % CI 1.257-2.581, P = 0.001). In addition, high COX-2 expression tended to be associated with a poor 3-year survival (HR = 1.741, 95 % CI 0.762-3.979, P = 0.188), but the difference was not significant. Therefore, this meta-analysis demonstrated that high COX-2 expression might be an unfavorable prognostic effect in osteosarcoma.

A systematic review of vascular endothelial growth factor expression as a biomarker of prognosis in patients with osteosarcoma

Vascular endothelial growth factor (VEGF) plays an important role in the tumor angiogenesis, and its expression has been supposed to be a biomarker of prognosis in patients with osteosarcoma. There are many studies assessing the prognostic role of VEGF expression in osteosarcoma, and no consistent outcomes are reported. To provide a comprehensive assessment of the prognostic role of VEGF expression, we performed a systematic review and meta-analysis of published studies. We assessed the effect of VEGF expression on the overall survival rate and the disease-free survival rate by calculating the pooled odds ratio (OR) with corresponding 95 % confidence interval (95 %CI). Finally, 12 studies with a total of 559 osteosarcoma patients were included into the systematic review and meta-analysis. Compared with osteosarcoma patients with low or negative VEGF expression, patients with high VEGF expression were obviously associated with lower disease-free survival (OR=0.25, 95 %CI 0.11-0.58, P=0.001, I (2) =56.4 %). In addition, patients with high VEGF expression were obviously associated with lower overall survival (OR=0.22, 95 %CI 0.13-0.35, P<0.001, I (2) =0.0 %). Therefore, the findings from this systematic review suggest that VEGF expression is an effective biomarker of prognosis in patients with osteosarcoma.

Protein kinase C epsilon and genetic networks in osteosarcoma metastasis

Osteosarcoma (OS) is the most common primary malignant tumor of the bone, and pulmonary metastasis is the most frequent cause of OS mortality. The aim of this study was to discover and characterize genetic networks differentially expressed in metastatic OS. Expression profiling of OS tumors, and subsequent supervised network analysis, was performed to discover genetic networks differentially activated or organized in metastatic OS compared to localized OS. Broad trends among the profiles of metastatic tumors include aberrant activity of intracellular organization and translation networks, as well as disorganization of metabolic networks. The differentially activated PRKCε-RASGRP3-GNB2 network, which interacts with the disorganized DLG2 hub, was also found to be differentially expressed among OS cell lines with differing metastatic capacity in xenograft models. PRKCε transcript was more abundant in some metastatic OS tumors; however the difference was not significant overall. In functional studies, PRKCε was not found to be involved in migration of M132 OS cells, but its protein expression was induced in M112 OS cells following IGF-1 stimulation.

Prognostic significance of p53 expression in malignant bone tumors: a meta-analysis

Osteosarcoma and Ewing's sarcoma are the two most common primary malignant bone tumors, and findings of prognostic factors are important for clinicians to decide treatment options. High p53 expression has been implicated in tumor development and progression, but studies investigating the prognostic role of p53 overexpression in malignant bone tumors report conflicting findings. We performed a meta-analysis to assess the relationship between p53 overexpression and the survival of malignant bone tumors. A meta-analysis of 13 studies with a total of 703 patients was carried out to evaluate the association between p53 overexpression and overall survival (OS) and disease-free survival (DFS) in patients with malignant bone tumors. The pooled hazard ratio (HR) with its 95 % confidence interval (CI) was used as the effect size estimate. There was no between-study heterogeneity in both OS studies (I (2) = 0.0 %) and DFS studies (I(2) = 0.0 %). Overall, high p53 expression predicted both poor OS (HR 2.13, 95 % CI 1.81-2.52, P < 0.001) and poor DFS (HR 2.06, 95 % CI 1.58-2.69, P < 0.001) in patients with malignant bone tumors. Subgroup analyses by tumor types suggested that p53 expression predicted poor OS in both osteosarcoma patients (HR 2.15, 95 % CI 1.78-2.60, I (2) = 15.2 %, P < 0.001) and Ewing's sarcoma patients (HR 2.09, 95 % CI 1.47-2.97, I(2) = 0.0 %, P < 0.001). Besides, p53 expression also predicted poor DFS in both osteosarcoma patients (HR 2.38, 95 % CI 1.60-3.52, I(2) = 0.0 %, P < 0.001) and Ewing's sarcoma patients (HR 1.83, 95 % CI 1.28-2.63, I(2) = 0.0 %, P = 0.001). Egger's test also did not suggest evidence for publication bias in both OS studies (P = 0.615) and DFS studies (P = 0.258). High p53 expression indicates a poorer prognosis for patients with osteosarcoma and Ewing's sarcoma.

The cyclooxygenase-2 inhibitor NS-398 inhibits proliferation and induces apoptosis in human osteosarcoma cells via downregulation of the survivin pathway

Cyclooxygenase-2 (COX-2) is frequently overexpressed in human malignancies and plays a crucial role in tumorigenesis and cancer progression. The present study aimed to investigate the expression and clinical significance of COX-2 and survivin (SUV) in human osteosarcomas (OS), and explore the effects and molecular mechanisms of a selective COX-2 inhibitor NS-398 and SUV on tumor proliferation and apoptosis. Fifty cases of human OS and osteochondromas (OC) were collected. The expression of COX-2 and SUV was assessed using immunohistochemical assays in biopsy samples. MG-63 human OS cells were treated with different concentrations of NS-398, used to investigate their effects on cell proliferation and apoptosis. The recombinant small hairpin RNA adenovirus vector rAd5-SUV was constructed, and the effects and molecular mechanisms of knockdown of SUV on proliferation and apoptosis were evaluated in MG-63 cells. A subcutaneous xenograft tumor model was established, validating the effects of rAd5-SUV on tumor growth in vivo. Based on the results, the expression of COX-2 and SUV in OS showed a higher strong reactivity rate compared with OC (73.3 vs. 25.0%, P=0.001; 63.3 vs. 30.0%, P=0.02), but it did not correlate with the clinicopathological characteristics of OS. NS-398 inhibited proliferation, induced apoptosis and decreased the mRNA expression of COX-2 and SUV in MG-63 cells. Furthermore, adenovirus-mediated knockdown of SUV inhibited proliferation, induced apoptosis, reduced the expression of proliferating cell nuclear antigen (PCNA), increased the expression of caspase-3 (CAS-3) and slowed the growth of xenograft tumors in MG-63 cells. Taken together, the expression of COX-2 and SUV is closely correlated with human OS, and inhibition of COX-2 or knockdown of SUV suppresses tumor proliferation and induces apoptosis, suggesting that COX-2 may be involved in OS cell proliferation and apoptosis through SUV-mediated regulation of PCNA and CAS-3 expression, and provides a potential therapeutic strategy for the treatment of cancer.

Immunohistochemical investigation of cell cycle and apoptosis regulators (survivin, β-catenin, p53, caspase 3) in canine appendicular osteosarcoma

Background

Osteosarcoma (OSA) represents the most common canine primary bone tumour. Despite several pathways have been investigated so far, few molecules have been identified as prognostic tools or potential therapeutic targets, and there is still the need to find out molecular pathways with specific influence over OSA progression to facilitate earlier prognosis and treatment.

Aims of the present study were to evaluate the immunohistochemical pattern and levels of expression of a panel of molecules (survivin, β-catenin, caspase 3 -inactive and active forms- and p53) involved in cell cycle and apoptosis regulation in canine OSA samples, known to be of interest in the study also of human OSA, and to detect specific relations among them and with histological tumour grade, disease free interval (DFI) and overall survival (OS).

Results

Nuclear β-catenin immunostaining was detected in normal osteoblasts adjacent to the tumour, and in 47% of the cases. Cytoplasmic and/or membranous immunostaining were also observed. Nuclear survivin and p53 positive cells were found in all cases. Moderate/high cytoplasmic β-catenin expression (≥10% positive cells) was significantly associated with the development of metastasis (P = 0.014); moderate/high nuclear p53 expression (≥10% positive cells) was significantly associated with moderate/high histological grade (P = 0.017) and shorter OS (P = 0.049). Moderate/high nuclear survivin expression (≥15% positive cells) showed a tendency toward a longer OS (P = 0,088).

Conclusions

The present results confirmed p53 as negative prognostic marker, while suggested survivin as a potential positive prognostic indicator, rather than indicative of a poor prognosis. The detection of nuclear β-catenin immunostaining in normal osteoblasts and the absent/low expression in most of the OSAs, suggested that this pathway could not play a major role in oncogenic transformation of canine osteoblasts. Further studies are needed to confirm these hypotheses.

The prognostic value of elevated vascular endothelial growth factor in patients with osteosarcoma: a meta-analysis and systemic review

BACKGROUND

Osteosarcoma is a primary malignancy of bone. Although new therapies continue to emerge, osteosarcoma-related morbidity and mortality remain high. Various studies have evaluated the prognostic value of VEGF levels in osteosarcoma patients, but they have yielded conflicting results.

METHODS

The 5-year survival of each study was aggregated following a methodological assessment, and a systematic review of eligible studies with meta-analysis and univariate analysis was performed to quantitatively review the correlation of VEGF overexpression with 5-year survival in patients with osteosarcoma.

RESULTS

A total of 387 patients in eleven papers were finally considered to be eligible for inclusion in our analysis. Aggregation of the 6 positive results in Kaplan-Meier curve showed a risk ratio of 2.84 (95% CI: 1.39-5.83, P = 0.004) associated with VEGF-positive conditions in comparison with VEGF-negative conditions, suggesting that there was significant association between VEGF positive and the 5-year mortality. But univariate analysis of eleven studies showed that there was a small inverse but not significant relationship between VEGF expression level and the 5-year survival of osteosarcoma patients, but stage III, neo-chemotherapy, the primary tumor location, osteoblastic histological subtype and the source of patients showed a significant impact on the 5-year survival of patients.

CONCLUSIONS

The prognostic significance of VEGF expression in all its isoforms is still unknown based on the limited data available, but we find VEGF165 may play an important role. Future studies should examine the relationship between VEGF isoform expression and patients' survival and the relationship between VEGF isoform expression and EMMPRIN expression, which could be helpful for predicting the prognosis of patients with osteosarcoma. Once the conclusion of whether the VEGF and its isoforms playing a role in osteosarcoma were reached, it would help guide clinical decision-making regarding therapy and outcomes. In addition, we recommend a >25% positive staining of the cells as a VEGF-positive cut-off value in immunohistochemistry, since we find a relatively strict detecting method is likely to yield significant result in the 5-year survival of patients.