Chemotherapy for osteosarcoma – Where does it come from? What is it? Where is it going?

Alterations in Serum Lipids and Lipoproteins Induced by Neoadjuvant Chemotherapy in Patients with Osteosarcoma around the Knee Joint: A Retrospective Analysis

OBJECTIVE

To investigate the serum lipid profiles of patients with localized osteosarcoma around the knee joint before and after neoadjuvant chemotherapy.

METHODS

After retrospectively screening the data of 742 patients between January 2007 and July 2020, 50 patients aged 13 to 39 years with Enneking stage II disease were included in the study. Serum lipid levels, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipoprotein-α [Lp(a)], and apolipoprotein A1, B, and E (ApoA1, ApoB, and ApoE), and clinicopathological characteristics were collected before and after neoadjuvant chemotherapy.

RESULTS

The mean levels of TC, TG, and ApoB were significantly increased following neoadjuvant chemotherapy (16%, 38%, and 20%, respectively, vs. pretreatment values; P<0.01). The mean levels of LDL-C and ApoE were also 19% and 16% higher, respectively (P<0.05). No correlation was found between the pretreatment lipid profile and the histologic response to chemotherapy. An increase in Lp(a) was strongly correlated with the Ki-67 index (R=0.31, P=0.023). Moreover, a trend toward longer disease-free survival (DFS) was observed in patients with decreased TG and increased LDL-C following chemotherapy, although this difference was not statistically significant (P=0.23 and P=0.24, respectively).

CONCLUSION

Significant elevations in serum lipids were observed after neoadjuvant chemotherapy in patients with localized osteosarcoma. There was no prognostic significance of pretreatment serum lipid levels on histologic response to neoadjuvant chemotherapy. The scale of increase in serum Lp(a) might have a potential prognostic role in osteosarcoma. Patients with increased LDL-C or reduced TG after chemotherapy seem to exhibit a trend toward favorable DFS.

Low-energy shock waves promote the cisplatin chemosensitivity of human osteosarcoma MNNG/HOS cells via the P2X7/Akt/mTOR pathway

Background

The current dilemma of osteosarcoma treatment is the resistance of chemotherapeutic drugs after long-term usage, which also introduces life-threatening side effects.

Methods and results

To minimize chemoresistance in osteosarcoma patients, the authors applied shock waves (SWs) to human osteosarcoma MNNG/HOS cells, then evaluated the cell viability and extracellular ATP levels, and further investigated the effect of SWs on cisplatin (DDP) cytotoxicity in MNNG/HOS cells. The authors' results showed that 400 SW pulses at 0.21 mJ/mm2 exhibited little influence on the MNNG/HOS cell viability. In addition, this SW condition significantly promoted the extracellular ATP release in MNNG/HOS cells. Importantly, low-energy SWs obviously increased Akt and mammalian target of rapamycin (mTOR) phosphorylation and activation in MNNG/HOS cells, which could be partially reversed in the presence of P2X7 siRNA. The authors also found that low-energy SWs strongly increased the DDP sensitivity of MNNG/HOS cells in the absence of P2X7.

Conclusions

For the first time, the authors found that SW therapy reduced the DDP resistance of MNNG/HOS osteosarcoma cells when the ATP receptor P2X7 was downregulated. SW therapy may provide a novel treatment strategy for chemoresistant human osteosarcoma.

Discovery of potent thiazolidin-4-one sulfone derivatives for inhibition of proliferation of osteosarcoma in vitro and in vivo

Chemotherapy combining with surgical treatment has been the main strategy for osteosarcoma treatment in clinical. Due to unclear pathogenesis and unidentified drug targets, significant progress has not been made in the development of targeted drugs for osteosarcoma during the past 50 years. Our previous discovery reported compound R-8i with a high potency for the treatment of osteosarcoma by phenotypic screening. However, both the metabolic stability and bioavailability of R-8i are poor (T1/2 = 5.36 min, mouse liver microsome; and bioavailability in vivo F = 52.1 %, intraperitoneal administration) which limits it use for further drug development. Here, we described an extensive structure-activity relationship study of thiazolidine-4-one sulfone inhibitors from R-8i, which led to the discovery of compound 68. Compound 68 had a potent cellular activity with an IC50 value of 0.217 μM, much higher half-life (T1/2 = 73.8 min, mouse liver microsome) and an excellent pharmacokinetic profile (in vivo bioavailability F = 115 %, intraperitoneal administration). Compound 68 also showed good antitumor effects and low toxicity in a xenograft model (44.6 % inhibition osteosarcoma growth in BALB/c mice). These results suggest that compound 68 is a potential drug candidate for the treatment of osteosarcoma.

Is Ancient Medical Treatment an Option for Curating Osteosarcoma Combined with Chemotherapy? A Basic Analysis of Clinic Pharmacy

BACKGROUND

As a malignant tumor, osteosarcoma (OS) ranks first place among adolescent cancers and is susceptible to developing resistance to chemotherapeutic agents. Differently, Traditional Chinese medicine (TCM) has multiple pharmacodynamic targets and complex biological components, which can inhibit tumor survival and drug resistance and gradually play an important role in the treatment of sarcoma.

METHODS

This study is to systematically evaluate the safety and efficacy of TCM combined with chemotherapy performed in the clinical treatment of OS. Based on multiple mainstream databases, eleven articles on the relationship between natural products and chemotherapy involving 656 patients were selected from all the literature published as of June 2022. Revman 5.4 software was used for a comprehensive search analysis, supplemented by established exclusion criteria, the Jadad scale, and the evaluation methods provided by Cochrane.

RESULTS

The efficiency of TCM combined with chemotherapy was significantly increased compared with chemical drugs alone [OR=2.56, 95% CI (1.36,4.79), Z=2.92, P=0.003]. Meanwhile, the adverse reactions such as nausea and vomiting, hepatotoxicity, and hematological changes caused by chemical drugs were alleviated correspondingly.

CONCLUSION

This study indicates that the mode of TCM combined with chemotherapy sheds light on the clinical treatment of OS, which is much better than the one-way mode.

Mechanism and Role of Endoplasmic Reticulum Stress in Osteosarcoma

Osteosarcoma is the most common malignant bone tumor, often occurring in children and adolescents. The etiology of most patients is unclear, and the current conventional treatment methods are chemotherapy, radiotherapy, and surgical resection. However, the sensitivity of osteosarcoma to radiotherapy and chemotherapy is low, and the prognosis is poor. The development of new and useful treatment strategies for improving patient survival is an urgent need. It has been found that endoplasmic reticulum (ER) stress (ERS) affects tumor angiogenesis, invasion, etc. By summarizing the literature related to osteosarcoma and ERS, we found that the unfolded protein response (UPR) pathway activated by ERS has a regulatory role in osteosarcoma proliferation, apoptosis, and chemoresistance. In osteosarcoma, the UPR pathway plays an important role by crosstalk with autophagy, oxidative stress, and other pathways. Overall, this article focuses on the relationship between ERS and osteosarcoma and reviews the potential of drugs or gene targets associated with ERS for the treatment of osteosarcoma.

Lipid Nanoparticles and Liposomes for Bone Diseases Treatment

Because of their outstanding biocompatibility, sufficient capacity to control drug release, and passive targeting capability, lipid nanoparticles are one of the world's most widely utilized drug delivery systems. However, numerous disadvantages limit the use of lipid nanoparticles in clinical settings, especially in bone regeneration, such as challenges in transporting, storing, and maintaining drug concentration in the local area. Scaffolds are frequently employed as implants to provide mechanical support to the damaged area or as diagnostic and imaging tools. On the other hand, unmodified scaffolds have limited powers in fostering tissue regeneration and curing illnesses. Liposomes offer a solid foundation for the long-term development of various commercial solutions for the effective drug delivery-assisted treatment of medical conditions. As drug delivery vehicles in medicine, adjuvants in vaccination, signal enhancers/carriers in medical diagnostics and analytical biochemistry, solubilizers for various ingredients as well as support matrices for various ingredients, and penetration enhancers in cosmetics are just a few of the industrial applications for liposomes. This review introduces and discusses the use of lipid nanoparticles and liposomes and the application of lipid nanoparticles and liposome systems based on different active substances in bone diseases.

Graphene Oxide Nanoplatforms to Enhance Cisplatin-Based Drug Delivery in Anticancer Therapy

Chemotherapeutics such as platinum-based drugs are commonly used to treat several cancer types, but unfortunately, their use is limited by several side effects, such as high degradation of the drug before entering the cells, off-target organ toxicity and development of drug resistance. An interesting strategy to overcome such limitations is the development of nanocarriers that could enhance cellular accumulation in target cells in addition to decreasing associated drug toxicity in normal cells. Here, we aim to prepare and characterize a graphene-oxide-based 2D nanoplatform functionalised using highly branched, eight-arm polyethylene-glycol, which, owing to its high number of available functional groups, offers considerable loading capacity over its linear modalities and represents a highly potent nanodelivery platform as a versatile system in cancer therapy. The obtained results show that the GO@PEG carrier allows for the use of lower amounts of Pt drug compared to a Pt-free complex while achieving similar effects. The nanoplatform accomplishes very good cellular proliferation inhibition in osteosarcoma, which is strictly related to increased cellular uptake. This enhanced cellular internalization is also observed in glioblastoma, although it is less pronounced due to differences in metabolism compared to osteosarcoma. The proposed GO@PEG nanoplatform is also promising for the inhibition of migration, especially in highly invasive breast carcinoma (i.e., MDA-MB-231 cell line), neutralizing the metastatic process. The GO@PEG nanoplatform thus represents an interesting tool in cancer treatment that can be specifically tailored to target different cancers.

Doxorubicin-induced novel circRNA_0004674 facilitates osteosarcoma progression and chemoresistance by upregulating MCL1 through miR-142-5p

Accumulating evidence has shown that circular RNA (circRNA) dysregulation is involved in various types of cancer, including osteosarcoma (OS). Nevertheless, the role and mechanism of circRNAs in OS progression and chemoresistance remain elusive. We found that a novel doxorubicin-induced circular RNA, hsa_circ_0004674, screened by whole total transcriptome RNA sequencing in our previous study, was upregulated in OS chemoresistant cell lines and tissues and also connected with patients’ poor prognosis. Circ_0004674 knockdown remarkably suppressed OS cell chemoresistance, proliferation, migration, invasion, OS tumor growth, and enhanced cell cycle arrest and apoptosis in vitro and in vivo through control the expression of the antiapoptotic protein MCL1, a member of the Bcl-2 gene family. Further online bioinformatics analysis revealed that miR-142-5p had potential binding sites that can bind circ_0004674 and the 3′UTR of MCL1 mRNA. Moreover, the expression and function of miR-142-5p were conversely correlated with circ_0004674 in vitro. RIP, pull-down, luciferase assay, and RNA FISH demonstrated that circ_0004674 could compete with MCL1 for miR-142-5p binding to counteract miR-142-5p-mediated repression of MCL1 at the post-transcriptional level. To sum up, our study sheds light on the critical role of the oncogenic circ_0004674/miR-142-5p/MCL1 axis in OS progression and chemoresistance, providing a novel potential target for OS therapy.

Risk factors of regional lymph node (RLN) metastasis among patients with bone sarcoma and survival of patients with RLN-positive bone sarcoma

Background

Regional lymph node metastasis (RLNM) has been reported to be a prognostic factor for poor survival outcomes of bone sarcoma. However, studies about risk factors for RLNM of bone sarcoma are extremely rare, and the outcome of such patients remains to be explored. We aimed to identify risk factors for RLNM of bone sarcoma and conduct survival analysis for patients with bone sarcoma with RLNM.

Methods

A total of 10,641 patients confirmed of malignant bone sarcomas from 1983 to 2014 were identified from the Surveillance, Epidemiology, and End Results (SEER) database, with 311 being regional lymph node positive. Logistic regression analysis was used to identify risk factors for RLNM, while the Cox proportional hazards model and the Fine and Gray’s regression model were used for survival analysis.

Results

The proportion of RLNM was 6.0% in Ewing sarcoma, 2.5% in osteosarcoma and 1.1% in chondrosarcoma. Other bone tumors together had a RLNM rate of 4.2%. Risk factors identified by the logistic regression analysis for RLNM were male patients, primary tumor site, tumor type and size. The multivariate Cox regression analysis suggested age, race, distant metastasis, tumor type and surgical treatment to be prognostic factors for the overall survival of patients with RLNM. Taking non-cancer-specific death as a competing risk, however, we found only age between 30–60 years [sub-distribution hazard ratio (SHR), 1.528, 95% CI, 1.028–2.271; P=0.02], distant metastasis (SHR, 2.418, 95% CI, 1.682–3.474; P<0.001) and surgery treatment (SHR, 0.493, 95% CI, 0.339–0.718; P<0.001) remained significant for the cancer-specific survival in the Fine and Gray’s regression model.

Conclusions

Predictive factors for RLNM of bone sarcoma are sex, tumor site, type and size. In the presence of RKNM, only age, distant metastasis and surgery treatment are prognostic factors for the outcome of patients with bone sarcoma.

NDUFA4L2 Regulated by HIF-1α Promotes Metastasis and Epithelial-Mesenchymal Transition of Osteosarcoma Cells Through Inhibiting ROS Production

Osteosarcoma (OS) accounts for a large proportion of the types of bone tumors that are newly diagnosed, and is a relatively common bone tumor. However, there are still no effective treatments for this affliction. One interesting avenue is related to the mitochondrial NDUFA4L2 protein, which is encoded by the nuclear gene and is known to be a critical mediator in the regulation of cell survival. Thus, in this study, we aimed to investigate the effect of NDUFA4L2 upon the metastasis and epithelial–mesenchymal transition of OS. We found that NDUFA4L2 protein expression was upregulated in hypoxic conditions. We also used 2-ME and DMOG, which are HIF-1α inhibitors and agonists, respectively, to assess the effects related to decreasing or increasing HIF-1α expression. 2-ME caused a significant decrease of NDUFA4L2 expression and DMOG had the opposite effect. It was obvious that down-regulation of NDUFA4L2 had a direct interaction with the apoptosis of OS cells. Western blotting, wound healing analyses, Transwell invasion assays, and colony formation assays all indicated and supported the conclusion that NDUFA4L2 promoted OS cell migration, invasion, proliferation, and the epithelial–mesenchymal transition. During experiments, we incidentally discovered that autophagy and the ROS inhibitor could be used to facilitate the rescuing of tumor cells whose NDUFA4L2 was knocked down. Our findings will help to further elucidate the dynamics underlying the mechanism of OS cells and have provided a novel therapeutic target for the treatment of OS.

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.

Multifunctional bone cement for synergistic magnetic hyperthermia ablation and chemotherapy of osteosarcoma

Myelosuppression, gastrointestinal toxicity and hypersensitivities always accompany chemotherapy of osteosarcoma (OS). In addition, the intricate karyotype of OS, the lack of targeted antitumor drugs and the bone microenvironment that provides a protective alcove for tumor cells reduce the therapeutic efficacy of chemotherapy. Here, we developed a multifunctional bone cement loaded with Fe₃O₄ nanoparticles and the antitumor drug doxorubicin (DOX/Fe₃O₄@PMMA) for synergistic MH ablation and chemotherapy of OS. The localized intratumorally administered DOX/Fe₃O₄@PMMA can change from liquid into solid at the tumor site via a polyreaction. The designed multifunctional bone cement was constructed with Fe₃O₄ nanoparticles, PMMA, and an antitumor drug approved by the U.S. Food and Drug administration (FDA). The injectability, magnetic hyperthermia (MH) performance, controlled drug release profile, and synergistic therapeutic effect of DOX/Fe₃O₄@PMMA in vitro were investigated in detail. Furthermore, the designed DOX/Fe₃O₄@PMMA controlled the release of DOX, enhanced the apoptosis of OS tissue, and inhibited the proliferation of tumor cells, demonstrating synergistic MH ablation and chemotherapy of OS in vivo. The biosafety of DOX/Fe₃O₄@PMMA was also evaluated in detail. This strategy significantly reduced surgical time, avoided operative wounds and prevented patient pain, showing a great clinical translational potential for OS treatment.

Insight Into the Role of Autophagy in Osteosarcoma and Its Therapeutic Implication

Osteosarcoma is an aggressive bone cancer that frequently metastasizes to the lungs. The cytotoxicity of most chemotherapeutics and targeted drugs in the treatment of osteosarcoma is partially lessened. Furthermore, there is a poor response to current chemo- and radiotherapy for both primary lesions and pulmonary metastases of osteosarcoma. There is a clear need to explore promising drug candidates that could improve the efficacy of osteosarcoma treatment. Autophagy, a dynamic and highly conserved catabolic process, has dual roles in promoting cell survival as well as cell death. The role of autophagy has been investigated extensively in different tumor types, and a growing body of research has highlighted the potential value of using autophagy in clinical therapy. Here, we address significant aspects of autophagy in osteosarcoma, including its functions, modulation, and possible therapeutic applications.

LncRNA DLX6-AS1 promotes tumor proliferation and metastasis in osteosarcoma through modulating miR-641/HOXA9 signaling pathway

Osteosarcoma (OS) is the most common primary malignant bone tumor. Recently, increasing evidence has shown that the long noncoding RNA (lncRNA) DLX6-AS1 (distal-less homeobox 6 antisense 1) plays significant roles in various types of cancers. However, the functions and underlying mechanisms of DLX6-AS1 have not been explored in OS yet. In this study, we assessed the expression of DLX6-AS1 in OS tissues and cell lines and explored the underlying molecular mechanisms. DLX6-AS1 was found to be significantly upregulated in OS tissues and OS cell lines. High expression of DLX6-AS1 was significantly correlated with advanced TNM stage, high tumor grade, and distant metastasis of patients with OS. Knockdown of DLX6-AS1 suppressed OS cell proliferation, invasion, and migration, and induced cell apoptosis. Knockdown of DLX6-AS1 also suppressed in vivo tumor growth. Bioinformatics and luciferase assay analysis showed that DLX6-AS1 functioned as a competing endogenous RNA (ceRNA) to negatively regulate miR-641 expression. Furthermore, miR-641 was found to target the 3' untranslated region of homeobox protein Hox-A9 (HOXA9) and suppressed the expression of HOXA9. Mechanistic studies showed that DLX6-AS1 regulated OS cell proliferation, invasion, and migration via regulating HOXA9 by acting as a ceRNA for miR-641. Our results suggested that DLX6-AS1 functions as a ceRNA by targeting miR-641/HOXA9 signal pathway to suppress OS cell proliferation and metastasis. Our study may provide novel insights into understanding pathogenesis and development of OS.

Effect of RAB31 silencing on osteosarcoma cell proliferation and migration through the Hedgehog signaling pathway

Osteosarcoma (OS) is a prevalent cancer that plagues people worldwide. Identifying prognostic markers would be useful in treating human OS. In this study, we aimed to explore the functions of Ras-related protein Rab-31 (RAB31) in OS-cell proliferation, migration, and invasion as well as its roles in the Hedgehog signaling pathway for better understanding of the mechanism. To assess the detailed regulatory mechanism of RAB31 silencing on OS, both RT-qPCR and Western blot analysis were employed to evaluate the expressions of RAB31 as well as the Hedgehog signaling pathway-related genes. Besides, we also investigated the effects of silenced RAB31 both in vitro and in vivo. First, we found that in OS tissues, both mRNA and protein expressions of RAB31 and PCNA had a significant increase. Second, the Hedgehog signaling pathway was detected to play an integral role in OS progression. Finally, after transfection of RAB31-siRNA to reduce the expression of RAB31, the Hedgehog signaling pathway was suppressed, along with cell proliferation, invasion, and migration. Therefore, we conclude that RAB31 plays an important role in OS development and its silencing delays the OS progression via suppression of the Hedgehog signaling pathway.

Screening candidate microRNA-mRNA network for predicting the response to chemoresistance in osteosarcoma by bioinformatics analysis

The search for biomarkers is important for providing more targeted treatments for osteosarcoma patients with chemoresistance. In this study, differentially expressed microRNAs (miRNAs) were identified from miRNA expression profiles. And the target messenger RNAs (mRNAs) of miRNA were obtained from two websites in public domains. Analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway by these miRNA targets suggests that they may have potential links to osteosarcoma chemoresistance. In the protein-protein interaction (PPI) network, we screened three subnetworks and 10 hub RNAs, and analyzed through KEGG pathway and searched the PubMed database, indicating that they were significantly associated with drug resistance. Then we found 12 key mRNAs by analyzing the mRNA expression profile. Survival analyses showed that most of the 10 hub mRNAs and 12 key mRNAs had a significant influence on the prognosis of patients with chemoresistance osteosarcoma. A miRNA-mRNA network is constructed by integrating mRNAs and miRNAs information. The network biomarkers in this study have an advantage over traditional single-molecule biomarkers in terms of predictive power. And the mRNAs in this network biomarkers are supported by survival analysis or by existing theories. These results will contribute to the choice of chemotherapy before treatment and the prediction of patient prognosis.

The expression of Eps15 homology domain 1 is negatively correlated with disease-free survival and overall survival of osteosarcoma patients

Background

Osteosarcoma was locally aggressive and frequently metastasizes to the lung. However, the etiology of osteosarcoma was unknown. Thus, exploring the mechanisms behind the occurrence of osteosarcoma was important for its prediction and prevention. To investigate the usefulness of mammalian Eps15 homology domain 1 (EHD1) as a prognostic marker for osteosarcoma, the expression of EHD1 in 57 osteosarcoma patients was measured using immunohistochemistry techniques and correlated with the clinicopathological features of patients.

Methods

Correlations of EHD1 expression levels with clinicopathological features of patients were assessed using the Pearson χ² test for categorical variables and the Student t test for continuous variables. Cumulative disease-free survival (DFS) curves and overall survival (OS) curves were plotted using the Kaplan–Meier method, and the relationship between each of the variables and survival was assessed by log-rank tests using univariate analysis. Subsequently, the parameters were tested using the multivariate Cox proportional hazards model, which was used to identify independent variables for predicting survival. EHD1 expression [P = 0.020; HR, 5.582; 95% confidence intervals (CI), 1.314–23.72] was an independent prognostic indicator of DFS in osteosarcoma patients; tumor size and EHD1 expression of osteosarcomas were independent prognostic indicators of OS in osteosarcoma patients.

Results

EHD1 protein expression was a positive expression in examined tumor tissues. The median OS time of patients with high expression of EHD1 was 46.8 months (95% CI, 29.8–63.8 months), and the median OS time of patients with low expression of EHD1 was 58.8 months (95% CI, 31.6–86.0 months). The prognosis for patients with low expression of EHD1 in osteosarcomas was significantly better than that for patients with high expression of EHD1 (log-rank test, P = 0.019).

Conclusion

The expression of EHD1 was negatively correlated with DFS and OS of osteosarcoma patients; therefore, the expression of EHD1 is a prognostic marker for prediction and prevention of osteosarcomas.

Non‑covalent proteasome inhibitor PI‑1840 induces apoptosis and autophagy in osteosarcoma cells

Osteosarcoma (OS) is the predominant form of primary bone malignancy in children and adolescents. Although the combination of chemotherapy and modified surgical therapy leads to marked improvements in the survival rate, the therapeutic outcomes remain unsatisfactory. Therefore, the identification of novel drugs with higher efficacy and fewer side‑effects is urgently required. Proteasome inhibitors have been approved by the Food and Drug Administration (FDA) for the treatment of certain cancers, although none of them are directed against OS. Non‑covalent proteasome inhibitors, such as PI‑1840, are superior to covalent ones in numerous respects in view of their chemical structure; however, to date, no studies have been published on the effects of non‑covalent proteasome inhibitors on OS cells. In the present study, the antineoplastic effects of PI‑1840 were systematically evaluated in the OS cell lines, MG‑63 and U2‑OS. Cell viability and morphological changes were assessed by Cell Counting Kit‑8 (CCK‑8) and live/dead assays. The cell cycle was analyzed using flow cytometry (FCM) and western blot analysis (assessing the levels of the proteins p21, p27, and the tyrosine kinase, WEE1). The extent of cell apoptosis and autophagy were assessed by FCM, western blot analysis [of the apoptosis‑associated proteins, microtubule‑associated protein 1 light chain 3 α (LC3) and Beclin1], and mRFP‑GFP‑LC3 adenovirus transfection assay. Transwell and wound healing assays, and western blot analysis of the matrix metalloproteinases (MMPs)2 and 9 were performed to preliminarily evaluate the migration and invasion capability of the cells. In the present study, our results revealed that PI‑1840 inhibited the proliferation of OS cells and induced apoptosis, partly due to attenuation of the nuclear factor‑κB (NF‑κB) pathway. In addition, PI‑1840‑induced autophagy was detected, and inhibiting the autophagy of the OS cells led to an increase in the survival rate of the U2‑OS cells rather than of the MG‑63 cells. Furthermore, PI‑1840 attenuated the migration and invasion capabilities of the OS cells. In conclusion, the present study revealed PI‑1840 to be a promising drug for the treatment of OS.

In vitro and in vivo anticancer effects of two quinoline-platinum(II) complexes on human osteosarcoma models

Platinum-based drugs, mainly cisplatin, are used for the treatment of several solid tumors such as OS. However, cisplatin treatment often results in the development of chemoresistance, leading therapeutic failure. We have previously reported that platinum complexes containing 8-hydroxyquinoline ligands have good antitumor activity against different cancer cell lines and with a different and better cytotoxic profile than cisplatin. Here, the anticancer properties of two different quinoline-platinum complexes [Pt(Cl)₂(quinoline)(dmso)] (1) [PtCl(8-O-quinoline)(dmso)] (2) on in vitro (2D and 3D) and in vivo models (xenograft tumor of human osteosarcoma in mice) are presented. In this order, [PtCl(8-O-quinoline)(dmso)] (2) impaired cell viability to have a more pronounced antitumor effect than cisplatin on MG-63 osteosarcoma cells (IC₅₀ 4 µM vs. 39 µM). Besides, [PtCl(8-O-quinoline)(dmso)] (2) increased ROS production in a dose-manner response and this compound induced early and late apoptotic fractions of human osteosarcoma cells. Finally, [PtCl(8-O-quinoline)(dmso)] (2) decreased the cell viability of multicellular spheroids and reduced the tumor volume on athymic nude mice N:NIH(S) Fox1^nu without inducing side effects. In this way, [PtCl(8-O-quinoline)(dmso)] (2) did not alter the normal cytoarchitecture of liver and kidney and the blood biomarkers (GPT, GOT, uremia, and creatinine) did not suffer modifications. Taken together, our data indicate that these compounds showed a better anticancer performance than cisplatin on in vitro and in vivo studies. These results showed the importance of chelation in the antitumor properties, suggesting that the [PtCl(8-O-quinoline)(dmso)] (2) might be a promising agent for the treatment of human osteosarcoma tumors resistant to cisplatin.

Inhibitory effect of MSH6 gene silencing in combination with cisplatin on cell proliferation of human osteosarcoma cell line MG63

Osteosarcoma (OS) is one of the most common primary bone malignancies, with the survival rate of patients with OS remaining low. Therefore, we conducted this study to identify the potential role combination of both MSH6 gene silencing and cisplatin (DDP) plays in OS cell proliferation and apoptosis. Microarray-based gene expression profiling was used to identify the differentially expressed genes (DEGs) in patients with OS, as well as microRNAs (miRNAs) that regulate the candidate gene. OS tissues from 67 patients with OS along with normal tissues from 24 amputee patients were collected for detection of the positive expression of mutS homolog 6 (MSH6) protein, mRNA, and protein expressions of c-myc, cyclin D1, l-2, B-cell lymphoma 2 (Bcl-2), Stathmin, proliferating cell nuclear antigen (PCNA), and Bcl-2-associated X (Bax). Moreover, after MSH6 silencing and DDP were treated on the selected human OS cell line MG63 with the highest expression of MSH6, cell viability, cell cycle distribution, and apoptosis were detected. The microarray analysis showed that MSH6 was upregulated in OS chip data. Furthermore, silencing MSH6 combined with DDP reduced expressions of c-myc, cyclin D1, Bcl-2, Stathmin, and PCNA, and elevated Bax expression, whereas inhibiting OS cell viability, impeding cell cycle distribution, and inducing apoptosis. In conclusion, our preliminary results indicated that the combination of MSH6 gene silencing coupled with DDP may have a better effect on the inhibition of OS cell proliferation and promote apoptosis, potentially providing targets for the OS treatment.

Improved microfluidic platform for simultaneous multiple drug screening towards personalized treatment

Development of new targeted therapies is a challenge in the battle against cancer. Although a variety of treatments is currently available, there is no technique for rapidly evaluating the response of cancer patients to the drug. In this work, a microfluidic platform for the real-time simultaneous analysis of the success rate of different nanoparticle based chemotherapeutic drugs is presented. Based on a previous planar chamber and a reported sensitivity enhancing strategy, linear and cross shape microstructures were integrated into the chamber dome of the microfluidic polydimethylsiloxane and glass platform in order to provide a higher fluid mixing and treatment-cell interaction. Several methotrexate (MTX) based treatments (free MTX, MTX loaded Lecithin-PVA nanoparticles, MTX loaded Lecithin-Tween 80 nanoparticles) as well as their respective controls (cell media and both blank nanoparticles) were recirculated through the microchamber over an osteosarcoma cell monolayer. These nanovehicles reduced cell population to less than 20% (LEC-PVA nanoparticles) and 2.3% (LEC-Tween nanoparticles), demonstrating that nanoparticles are a promising target therapy for cancer treatment. Moreover, microstructured platforms demonstrated a higher efficacy in the drug-screening process: due to the liquid folding a higher amount of nanoparticles was internalized by the cells and, therefore, results were observed faster. In fact, the time required to reduce cell viability to the half was nearly a 75% faster. Furthermore, this microfluidic platform offers the capability to test up to five different drugs simultaneously, making it a powerful tool to evaluate the effect of multiple drugs and determine the most effective and personalized treatment.

In vitro and in vivo characterization of stem-like cells from canine osteosarcoma and assessment of drug sensitivity

Cancer stem cell (CSC) self-renewing and drug resistance cause treatment failure and tumor recurrence. Osteosarcoma is an aggressive bone tumor characterized by biological and molecular heterogeneity, possibly dependent on CSCs. CSC identification in osteosarcoma and their efficient targeting are still open questions. Spontaneous canine osteosarcoma shares clinical and biological features with the human tumors, representing a model for translational studies. We characterized three CSC-enriched canine osteosarcoma cultures. In serum-free conditions, these CSC cultures grow as anchorage-independent spheroids, show mesenchymal-like properties and in vivo tumorigenicity, recapitulating the heterogeneity of the original osteosarcoma. Osteosarcoma CSCs express stem-related factors (Sox2, Oct4, CD133) and chemokine receptors and ligands (CXCR4, CXCL12) involved in tumor proliferation and self-renewal. Standard drugs for osteosarcoma treatment (doxorubicin and cisplatin) affected CSC-enriched and parental primary cultures, showing different efficacy within tumors. Moreover, metformin, a type-2 diabetes drug, significantly inhibits osteosarcoma CSC viability, migration and self-renewal and, in co-treatment with doxorubicin and cisplatin, enhances drug cytotoxicity. Collectively, we demonstrate that canine osteosarcoma primary cultures contain CSCs exhibiting distinctive sensitivity to anticancer agents, as a reliable experimental model to assay drug efficacy. We also provide proof-of-principle of metformin efficacy, alone or in combination, as pharmacological strategy to target osteosarcoma CSCs.

DownRegulated SOX4 Expression Suppresses Cell Proliferation, Migration, and Induces Apoptosis in Osteosarcoma In Vitro and In Vivo

The SOX4 transcription factor is involved in various cellular processes, such as embryonic development and differentiation. Deregulated expression of Sox4 in several human cancers has been reported to date, but its biological functions in the progression of osteosarcoma remain unclear. In this study, we found that the expression levels of SOX4 protein were significantly higher in high-grade osteosarcoma tissues and metastatic osteosarcoma tissues. Its overexpression was associated with poor prognosis in osteosarcoma. Knockdown of the SOX4 gene in the osteosarcoma cell lines resulted in decreased cell proliferation, migration, invasion, and induced apoptosis. After SOX4 gene silencing, the protein expression levels of Bax, Caspase-3, and P53 in osteosarcoma cells were significantly elevated, while the protein expression levels of Bcl-2, MMP2, and MMP9 were obviously decreased. In vivo analysis in nude mice further confirmed that knockdown of SOX4 suppressed tumor growth. In conclusion, SOX4 appears to be an important tumor oncogene in the regulation of osteosarcoma cell proliferation, apoptosis, and invasion, and it may be a potential target for effective osteosarcoma therapy.

Efficacy and safety of stereotactic radiosurgery for pulmonary metastases from osteosarcoma: Experience in 73 patients

Osteosarcoma pulmonary metastases are typically treated with resection and/or chemotherapy. We hypothesize that stereotactic radiosurgery (SRS) can be an alternative to surgery that can achieve high rates of local control with limited toxicity. From January 2005 to December 2013, 73 patients who developed pulmonary metastasis during period of adjuvant chemotherapy or follow-up were analyzed. 33 patients were treated by stereotactic radiosurgery using the body gamma-knife system. A total dose of 50 Gy was delivered at 5 Gy/fraction to the 50% isodose line covering the planning target volume, whereas a total dose of 70 Gy was delivered at 7 Gy/fraction to the gross target volume. The other 40 patients were treated by surgical resection. Four-year progression-free survival rate, four-year survival rate, median time of PRPFS (post-relapse progress-free survival) and PROS (post-relapse overall survival) in SRS group were parallel to that in surgical group. Patients tolerated gamma knife radiosurgery well. Our study demonstrates that SRS is well-tolerated with excellent local control and less complications. SRS should be considered as a potential option in patients with pulmonary metastases from osteosarcoma, especially in those who are medically inoperable, refuse surgery.

Suppression of heat shock protein 70 by siRNA enhances the antitumor effects of cisplatin in cultured human osteosarcoma cells

Although advances in chemotherapy have improved the prognosis for osteosarcoma, some patients do not respond sufficiently to treatment. Heat shock protein 70 (Hsp70) is expressed at high levels in cancer cells and attenuates the therapeutic efficacy of anticancer agents, resulting in a poorer prognosis. This study investigated whether small interfering RNA (siRNA)-mediated inhibition of Hsp70 expression in an osteosarcoma cell line would enhance sensitivity to cisplatin. The expression of Hsp70 with cisplatin treatment was observed by using Western blotting and real-time reverse transcription polymerase chain reaction (RT-PCR). Changes in the IC50 of cisplatin when Hsp70 was inhibited by siRNA were evaluated. Cisplatin's effectiveness in inducing apoptosis was assessed by assay of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), caspase-3 activity, and mitochondrial membrane potential. Up-regulation of Hsp70 expression was dependent on the concentration of cisplatin. Inhibition of Hsp70 expression significantly reduced the IC50 of cisplatin. When cisplatin was added to osteosarcoma cells with Hsp70 expression inhibited, a significant increase in apoptosis was demonstrated in TUNEL, caspase-3, and mitochondrial membrane potential assays. Inhibition of Hsp70 expression induced apoptosis in cultured osteosarcoma cells, indicating that Hsp70 inhibition enhanced sensitivity to cisplatin. Inhibition of Hsp70 expression may provide a new adjuvant therapy for osteosarcoma.

Downregulation of BZW2 inhibits osteosarcoma cell growth by inactivating the Akt/mTOR signaling pathway

Osteosarcoma is the most common malignant bone tumor in adolescents. The function of basic leucine zipper and W2 domains 2 (BZW2) in tumor progression has been reported. However, the role and mechanisms of BZW2 in osteosarcoma remain to be determined. The aim of the present study was to reveal the expression and biological functions of BZW2 in osteosarcoma and to elucidate the proximal mechanisms underlying these functions. The expression of BZW2 in osteosarcoma tissues and cell lines was assessed by qRT-PCR, western blotting and immunohistochemistry. BZW2 overexpression was detected in osteosarcoma cell lines. Clinically, BZW2 expression was higher in osteosarcoma tissues than in corresponding non-tumor tissues and was associated with advanced Enneking stage and tumor recurrence. The knockdown of BZW2 using siRNA inhibited osteosarcoma cell proliferation, colony-forming ability, and the cell cycle at the G2/M phase in vitro. Host signaling pathways affected by BZW2 were detected using a PathScan Intracellular Signaling Antibody Array kit. These data demonstrated that the knockdown of BZW2 suppresses protein phosphorylation in the Akt/mTOR signaling pathway. These observations suggest that BZW2 is upregulated and has a pro-tumor effect in osteosarcoma via activation of the Akt/mTOR signaling pathway and thus is a potential target for gene therapy.

LncRNA FENDRR sensitizes doxorubicin-resistance of osteosarcoma cells through down-regulating ABCB1 and ABCC1

Long noncoding RNAs (LncRNAs) act as crucial regulators in various cancers including osteosarcoma (OS), yet their potential roles and molecular mechanisms in OS chemoresistance remain unclear. In the present study, we investigated the role and potential regulatory mechanism of the most down-regulated expressed lncRNA, FENDRR screened by our previous lncRNA microarray analysis between the paired doxorubicin-resistant and sensitive human osteosarcoma cell lines (MG63/DXR vs MG63). FENDRR expression was down-regulated in the doxorubicin-resistant OS cell lines and tissues and negatively correlated to the poor prognosis of OS patients. Overexpression of FENDRR suppressed doxorubicin-resistance, G2/M phase of cell cycle, and promoted cell apoptosis of osteosarcoma cells in vitro and tumor growth in vivo whereas FENDRR knockdown had the opposite effects. In addition, we found that FENDRR was mainly located in the cytoplasm and could regulate the drug resistance of osteosarcoma cells by negatively affecting posttranscriptional expression of ABCB1 and ABCC1. Together, our study demonstrated that lncRNA FENDRR may act as an inhibitory molecule of doxorubicin-resistance through down-regulating the expression of ABCB1 and ABCC1 genes in osteosarcoma cells. These findings may extend the function of FENDRR in tumor progression and provide a novel target for reversing OS chemoresistance.

Effectiveness of multi-drug regimen chemotherapy treatment in osteosarcoma patients: a network meta-analysis of randomized controlled trials

Background

Osteosarcoma is the most common malignant bone tumour. Due to the high metastasis rate and drug resistance of this disease, multi-drug regimens are necessary to control tumour cells at various stages of the cell cycle, eliminate local or distant micrometastases, and reduce the emergence of drug-resistant cells. Many adjuvant chemotherapy protocols have shown different efficacies and controversial results. Therefore, we classified the types of drugs used for adjuvant chemotherapy and evaluated the differences between single- and multi-drug chemotherapy regimens using network meta-analysis.

Methods

We searched electronic databases, including PubMed (MEDLINE), EmBase, and the Cochrane Library, through November 2016 using the keywords “osteosarcoma”, “osteogenic sarcoma”, “chemotherapy”, and “random*” without language restrictions. The major outcome in the present analysis was progression-free survival (PFS), and the secondary outcome was overall survival (OS). We used a random effect network meta-analysis for mixed multiple treatment comparisons.

Results

We included 23 articles assessing a total of 5742 patients in the present systematic review. The analysis of PFS indicated that the T12 protocol (including adriamycin, bleomycin, cyclophosphamide, dactinomycin, methotrexate, cisplatin) plays a more critical role in osteosarcoma treatment (surface under the cumulative ranking (SUCRA) probability 76.9%), with a better effect on prolonging the PFS of patients when combined with ifosfamide (94.1%) or vincristine (81.9%). For the analysis of OS, we separated the regimens to two groups, reflecting the disconnection. The T12 protocol plus vincristine (94.7%) or the removal of cisplatinum (89.4%) is most likely the best regimen.

Conclusions

We concluded that multi-drug regimens have a better effect on prolonging the PFS and OS of osteosarcoma patients, and the T12 protocol has a better effect on prolonging the PFS of osteosarcoma patients, particularly in combination with ifosfamide or vincristine. The OS analysis showed that the T12 protocol plus vincristine or the T12 protocol with the removal of cisplatinum might be a better regimen for improving the OS of patients. However, well-designed randomized controlled trials of chemotherapeutic protocols are still necessary.

Electronic supplementary material

The online version of this article (doi:10.1186/s13018-017-0544-9) contains supplementary material, which is available to authorized users.

Antisense lncRNA FOXC2-AS1 promotes doxorubicin resistance in osteosarcoma by increasing the expression of FOXC2

Recent efforts have revealed that numerous natural antisense lncRNAs play a crucial role in the regulation of cancer biology. Here, based on our previous study, we further identified that the lncRNA FOXC2-AS1 and its antisense transcript FOXC2 are positively up-regulated in doxorubicin-resistant osteosarcoma cell lines and tissues, correlate with poor prognosis and promote doxorubicin resistance in osteosarcoma cells in vitro and in vivo. In addition, FOXC2-AS1 and FOXC2 are mainly located in the cytoplasm and form an RNA-RNA double-stranded structure in the overlapping region, which is necessary for FOXC2-AS1 to regulate the expression of FOXC2 at both the transcription and post-transcription levels. In addition, transcription factor FOXC2 also contributes to doxorubicin resistance through inducing the expression of the classical multi-drug resistance-related ABCB1 gene similar to FOXC2-AS1. Thus, we concluded that the lncRNA FOXC2-AS1 may promote doxorubicin resistance in OS by increasing the expression of transcription factor FOXC2, further facilitating ABCB1 expression. These findings demonstrate the potential underlying mechanism of FOXC2-AS1 in the regulation of doxorubicin resistance in OS and possibly provide a novel reversing target.

Advances in Bone-targeted Drug Delivery Systems for Neoadjuvant Chemotherapy for Osteosarcoma

Targeted therapy for osteosarcoma includes organ, cell and molecular biological targeting; of these, organ targeting is the most mature. Bone-targeted drug delivery systems are used to concentrate chemotherapeutic drugs in bone tissues, thus potentially resolving the problem of reaching the desired foci and minimizing the toxicity and adverse effects of neoadjuvant chemotherapy. Some progress has been made in bone-targeted drug delivery systems for treatment of osteosarcoma; however, most are still at an experimental stage and there is a long transitional period to clinical application. Therefore, determining how to combine new, polymolecular and multi-pathway targets is an important research aspect of designing new bone-targeted drug delivery systems in future studies. The purpose of this article was to review the status of research on targeted therapy for osteosarcoma and to summarize the progress made thus far in developing bone-targeted drug delivery systems for neoadjuvant chemotherapy for osteosarcoma with the aim of providing new ideas for highly effective therapeutic protocols with low toxicity for patients with osteosarcoma.

Proton Radiation Therapy for Local Control in a Case of Osteosarcoma of the Neck

A 33-year-old man with symptomatic, unresectable osteosarcoma of the neck experienced disease progression despite treatment with multiple systemic agents. Given the tumor location, adjacent to the spinal cord and encasing the brachial plexus, proton beam therapy was recommended instead of conventional photon radiation therapy. The treatment was delivered in 3 weekly 10 cobalt-gray equivalents fractions, and there was minimal associated toxicity. There has been significant improvement in the patient's presenting symptoms as well as radiologically stable disease at 1 year. A photon intensity-modulated radiation therapy plan was created retrospectively for dosimetric comparison and demonstrated noninferiority, thereby highlighting the need for judicious use of proton therapy in certain cases.

Generation of Osteosarcomas from a Combination of Rb Silencing and c-Myc Overexpression in Human Mesenchymal Stem Cells

Osteosarcoma (OS) was a malignant tumor occurring with unknown etiology that made prevention and early diagnosis difficult. Mesenchymal stem cells (MSCs), which were found in bone marrow, were claimed to be a possible origin of OS but with little direct evidence. We aimed to characterize OS cells transformed from human MSCs (hMSCs) and identify their association with human primary OS cells and patient survival. Genetic modification with p53 or retinoblastoma (Rb) knockdown and c-Myc or Ras overexpression was applied for hMSC transformation. Transformed cells were assayed for proliferation, differentiation, tumorigenecity, and gene expression profile. Only the combination of Rb knockdown and c-Myc overexpression successfully transformed hMSCs derived from four individual donors, with increasing cell proliferation, decreasing cell senescence rate, and increasing ability to form colonies and spheres in serum-free medium. These transformed cells lost the expression of certain surface markers, increased in osteogenic potential, and decreased in adipogenic potential. After injection in immunodeficient mice, these cells formed OS-like tumors, as evidenced by radiographic analyses and immunohistochemistry of various OS markers. Microarray with cluster analysis revealed that these transformed cells have gene profiles more similar to patient-derived primary OS cells than their normal MSC counterparts. Most importantly, comparison of OS patient tumor samples revealed that a combination of Rb loss and c-Myc overexpression correlated with a decrease in patient survival. This study successfully transformed human MSCs to OS-like cells by Rb knockdown and c-Myc overexpression that may be a useful platform for further investigation of preventive and target therapy for human OS. Stem Cells Translational Medicine 2017;6:512-526.

Construction of recombinant pEGFP-N1-hPer2 plasmid and its expression in osteosarcoma cells

The aim of this study was to construct the eukaryotic expression vector pEGFP-N1-hPer2 and assess its expression in the human osteosarcoma cell line MG63. Total mRNA was extracted from human osteosarcoma MG63 cells, the human period 2 (hPer2) gene was obtained by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into the pEGFP-N1 vector, then the recombinant pEGFP-N1-hPer2 plasmid was constructed and transfected into MG63 cells using Lipofectamine 2000. The expression of hPer2 in MG63 cells was measured by quantitative RT-PCR and western blot analysis. The accurate construction of pEGFP-N1-hPer2 was verified by double enzyme digestion and DNA sequencing. hPer2 gene expression in the transfected cells was assessed by RT-qPCR and western blot analysis. In conclusion, the recombinant pEGFP-N1-hPer2 plasmid was constructed successfully, and expressed effectively in MG63 cells.

YKL-40 protein in osteosarcoma tumor tissue

YKL-40, a cellular glycoprotein isolated from the human osteosarcoma (OS) cell line MG63, is increased in the blood of patients with various types of cancer, and is found as an independent prognostic variable for survival. YKL-40 is also present with variable intensity in the tumor cells of some cancer types, but survival results have been conflicting. The aim of this study was to investigate the tissue expression of YKL-40 and its possible role as a predictive marker in patients with OS. Forty-eight patients were included in the study. Diagnostic biopsies were analyzed by immunohistochemistry; YKL-staining scores as well as CD14 and CD163 scores were determined, and survival data were determined statistically. A universal intense immunostaining for YKL-40 was found in all tumor cells, but tumor cell/stroma ratio varied, and this ratio (%) served as staining score. Using 24% as mean score to divide the material, patients with tumors of high YKL-40 score had a better survival than patients with low score (p = 0.05). YKL-positive macrophages had no influence on the result. Unexpectedly and contrary to some other findings in cancer tissues, this study has shown a correlation between high YKL-40 tumor cell/matrix ratio and longer overall survival in OS.

Epiphyseal Sparing and Reconstruction by Frozen Bone Autograft after Malignant Bone Tumor Resection in Children

Limb salvage surgery has become the standard treatment for malignant primary bone tumors in the extremities. Limb salvage represents a challenge in skeletally immature patients. Several treatment options are available for limb reconstruction after tumor resection in children. We report our results using the technique of epiphyseal sparing and reconstruction with frozen autograft bone in 18 children. The mean follow-up period for the all patients included in this study is 72 ± 26 m. Eight patients remained disease-free, seven patients lived with no evidence of disease, two were alive but with disease, and one patient died of the disease. Five- and ten-year rates of survival were 94.4%. Graft survival at 5 and 10 years was 94.4%. Functional outcome using the Enneking scale was excellent in 17 patients (94.4%) and poor in one patient (5.5%). Complications include 2 nonunions, 2 fractures, 2 deep infections, 1 soft tissue recurrence, and leg length discrepancy in 7 cases. This technique is a good reconstructive choice in a child with a nonosteolytic primary or secondary bone tumor, responsive to chemotherapy, without involvement of the articular cartilage. It is a straight forward, effective, and biological technique, which affords immediate mobilization of joints and possible cryoimmune effects, with excellent long term functional outcome and less complication.

Resveratrol inhibits canonical Wnt signaling in human MG-63 osteosarcoma cells

In the last 30 years, the 5-year-survival rate of patients with osteosarcoma has not improved as a result of the low prevalence and large tumor heterogeneity. Therefore, the development of novel drugs for the treatment of osteosarcoma is urgently required. The present study aimed to identify potential novel drugs for the treatment of osteosarcoma, thus used β-catenin as a target and performed high content screening. In a total of 14 botanical extracts assessed, resveratrol markedly downregulated the expression of β-catenin and significantly inhibited MG-63 cell proliferation. CCK-8 assay was used to confirm the anti-osteosarcoma effect of resveratrol and flow cytometry and western blotting were performed to analyze the underlying mechanisms of the proapoptotic effects of resveratrol. β-catenin is a vital member of the canonical Wnt signaling pathway and, therefore, the target genes of this pathway were further analyzed. The results of this analysis demonstrated that resveratrol suppressed the MG-63 cells by inhibiting the canonical Wnt signaling pathway.

Inhibition of autophagy enhances cisplatin-induced apoptosis in the MG63 human osteosarcoma cell line

Autophagy is a significant catabolic process that allows the renewal of intracellular organelles, through which cells are able to maintain homeostasis. In addition, autophagy may be associated with the carcinogenesis of osteosarcoma (OS). Cisplatin (CDDP) is an alkylating agent that is commonly used as an anticancer therapy. However, the pathways underlying the effects of CDDP remain to be elucidated. The present study demonstrated that 3-methyladenine (3-MA), an inhibitor of autophagy, was able to increase the proliferation inhibition ratios of MG63 human OS cells when used in combination with CDDP. Furthermore, MG63 cells produced significantly more microtubule-associated protein light chain 3II (LC3II), a widely used marker for monitoring autophagy, following CDDP treatment. Treatment with 3-MA was observed to inhibit these changes. Similarly, MG63 cells co-treated with 3-MA and CDDP demonstrated increased sensitivity to CDDP-induced apoptosis, compared with those exposed to CDDP alone. The present study revealed variation in the expression of LC3II and caspase-3 activity following treatment with certain drugs. The results of the present study suggest that CDDP may be capable of inducing apoptosis and autophagy, and that autophagy may be able to inhibit apoptosis in MG63 cells. Therefore, downregulation of autophagy may increase the chemotherapeutic sensitivity of MG63 cells to CDDP.

Limb function and quality of life after various reconstruction methods according to tumor location following resection of osteosarcoma in distal femur

Background

We tried to compare the functional and psychosocial outcomes after various reconstruction methods according to tumor location following resection of osteosarcoma in distal femur.

Methods

We retrospectively reviewed 51 patients who underwent limb-salvage surgery of osteosarcoma in distal femur in our institution, 30 males and 21 females with an average age of 21 years (range 13–51 years). We classified osteosarcoma in distal femur into 3 types, and organized affected limb reconstruction methods after wide resection. MSTS and QOL scores were used to analyze the functional and psychological outcomes.

Results

After a mean follow-up of 43 months (12–225 months), there is no difference on functional results and QOL scores among three reconstruction groups (p > 0.05) and among three types groups (p > 0.05). No difference could be noticed on tumor-free survival and total survival among three reconstruction groups (p > 0.05) and three type groups (p > 0.05). In ≤2-year, better functional scores could be found in prosthesis group, rather than the other two inactivated-bone groups (p < 0.05).

Conclusions

Biological reconstruction with alcohol-inactivated autograft replantation could avoid prosthesis related complications and achieved comparable results with prosthesis following resection of osteosarcoma in distal femur. Different reconstruction options could be chosen according to tumor location, such as the distance to Insall line.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-453) contains supplementary material, which is available to authorized users.

Neuronal nitric oxide synthase induction in the antitumorigenic and neurotoxic effects of 2-methoxyestradiol

OBJECTIVE

2-Methoxyestradiol, one of the natural 17β-estradiol derivatives, is a novel, potent anticancer agent currently being evaluated in advanced phases of clinical trials. The main goal of the study was to investigate the anticancer activity of 2-methoxy-estradiol towards osteosarcoma cells and its possible neurodegenerative effects. We used an experimental model of neurotoxicity and anticancer activity of the physiological agent, 2-methoxyestradiol. Thus, we used highly metastatic osteosarcoma 143B and mouse immortalized hippocampal HT22 cell lines. The cells were treated with pharmacological (1 μM, 10 μM) concentrations of 2-methoxyestradiol.

EXPERIMENTAL

Neuronal nitric oxide synthase and 3-nitrotyrosine protein levels were determined by western blotting. Cell viability and induction of cell death were measured by MTT and PI/Annexin V staining and a DNA fragmentation ELISA kit, respectively. Intracellular levels of nitric oxide were determined by flow cytometry.

RESULTS

Here we demonstrated that the signaling pathways of neurodegenerative diseases and cancer may overlap. We presented evidence that 2-methoxyestradiol, in contrast to 17β-estradiol, specifically affects neuronal nitric oxide synthase and augments 3-nitrotyrosine level leading to osteosarcoma and immortalized hippocampal cell death.

CONCLUSIONS

We report the dual facets of 2-methoxyestradiol, that causes cancer cell death, but on the other hand may play a key role as a neurotoxin.

The long-term outcome following the use of frozen autograft treated with liquid nitrogen in the management of bone and soft-tissue sarcomas

In 1999, we developed a technique for biological reconstruction after excision of a bone tumour, which involved using autografts of the bone containing the tumour treated with liquid nitrogen. We have previously reported the use of this technique in 28 patients at a mean follow up of 27 months (10 to 54).

In this study, we included 72 patients who underwent reconstruction using this technique. A total of 33 patients died and three were lost to follow-up, at a mean of 23 months (2 to 56) post-operatively, leaving 36 patients available for a assessment at a mean of 101 months 16 to 163) post-operatively. The methods of reconstruction included an osteo-articular graft in 16, an intercalary in 13 and, a composite graft with prosthesis in seven.

Post-operative function was excellent in 26 patients (72.2%), good in seven (19.4%), and fair in three (8.3%) according to the functional evaluation system of Enneking. No recurrent tumour occurred within the grafts. The autografts survived in 29 patients (80.6%), and the rates of survival at five and ten years were 86.1% and 80.6 %, respectively. Seven of 16 osteo-articular grafts (44%) failed because of fracture or infection, but all the composite and intercalary grafts survived.

The long-term outcomes of frozen autografting, particularly using composite and intercalary grafts, are satisfactory and thus represent a good method of treatment for patients with a sarcoma of bone or soft tissue.

Cite this article: Bone Joint J 2014;96-B:555–61.