Bone Sarcomas in Pediatrics: Progress in Our Understanding of Tumor Biology and Implications for Therapy

An improved experimental model of osteosarcoma lung metastases to investigate innovative therapeutic interventions and sex as a biological variable

Osteosarcoma (OS) is the most common primary bone malignancy, with OS lung metastasis (OSLM) being the leading cause of death in OS patients. No curative pharmacotherapies for OSLM are available, highlighting the clinical need for new therapies. Improved and rigorous preclinical models of OSLM are key in supporting advancements in this field. We aimed to develop an immunocompetent mouse model of OSLM that allows monitoring pharmacotherapies' effect on the lung metastatic burden over time and assessing the impact of sex as a biological variable in tumor growth and response to therapy. We transformed K7M2 cells to express bioluminescence and fluorescence, enabling real-time tracking of OSLM in BALB/c mice following tail vein injection. Metastasis was confined to the lungs and exhibited exponential growth with typical downregulated Fas receptor expression. In vivo bioluminescence correlated strongly with ex vivo, suggesting its reliability for evaluating metastatic progression and therapy response. Fluorescence from tdT was stable upon tissue processing, providing unique opportunities to probe the tumor characteristics ex vivo. We also assessed the effect of local lung-delivered gemcitabine, which was well-tolerated and significantly reduced OSLM burden without causing pulmonary toxicity. However, treatment did not resolve metastatic disease. We also explored the effect of sex on tumor growth and response to therapy; while no difference was observed in tumor growth between male and female mice, females showed a better response to local gemcitabine administration. In sum, we established a robust and rigorous immunocompetent mouse model of OSLM that will facilitate exploring new pharmacotherapies for OSLM.

Orthopedic approaches for bone sarcoma: A bibliometric review of the 50 most cited papers

Background

Curative treatment of bone sarcoma is primarily based on operative management. The Orthopedic Oncology approach towards this disease has evolved greatly to the breakthrough in systemic treatment options as well as unique implant designs favoring limb salvage over amputations. The purpose of this study was to perform a bibliometric analysis of the top 50 most cited papers related to the orthopedic the approach to bone sarcomas.

Methods

We queried the ISI Web of Knowledge database in July 2022. Keywords utilized were: ""Bone Sarcoma" OR "Osteosarcoma" OR "Ewing Sarcoma" OR "Chondrosarcoma" OR "Chordoma". The top 50 articles pertaining to the orthopedic approach to bone sarcoma were included for analysis and included manuscript title, authors, citation count, journal and publication year.

Results

The mean number of citations are 187.06 (Range 125-400; SD 67.83). The average citations per year is 10.03 (Range 47.86-3.43; SD 8.05). Many articles were published from 2000 to 2009 (n = 20) and 1990-1999 (n = 13). The majority of the articles were published by institutions within the United States (n = 32). The most common level of evidence was level IV (n = 37). Majority of the articles focused on treatment outcome (n = 22).

Conclusion

This study offers a comprehensive review of the most cited literature regarding orthopedic approaches to bony sarcomas. Modern treatment approaches for bone sarcoma has resulted in an increased focus within the literature on achieving disease free survival wide tissue margins. Understanding the trends of available studies allows for physicians and researchers to target and innovate future areas of study.

Current and future targeted alpha particle therapies for osteosarcoma: Radium-223, actinium-225, and thorium-227

Osteosarcoma is a high-grade sarcoma characterized by osteoid formation, nearly universal expression of IGF1R and with a subset expressing HER-2. These qualities provide opportunities for the use of the alpha particle-emitting isotopes to provide targeted radiation therapy via alpha particles precisely to bone-forming tumors in addition to IFG1R or Her-2 expressing metastases. This review will detail experience using the alpha emitter radium-223 (²²³Ra, tradename Xofigo), that targets bone formation, in osteosarcoma, specifically related to patient selection, use of gemcitabine for radio-sensitization, and using denosumab to increasing the osteoblastic phenotype of these cancers. A case of an inoperable left upper lobe vertebral-paraspinal-mediastinal osteoblastic lesion treated successfully with ²²³Ra combined with gemcitabine is described. Because not all areas of osteosarcoma lesions are osteoblastic, but nearly all osteosarcoma cells overexpress IGF1R, and some subsets expressing Her-2, the anti-IGF1R antibody FPI-1434 linked to actinium-225 (²²⁵Ac) or the Her-2 antibody linked to thorium-227 (²²⁷Th) may become other means to provide targeted alpha particle therapy against osteosarcoma (NCT03746431 and NCT04147819).

223-Radium for metastatic osteosarcoma: combination therapy with other agents and external beam radiotherapy

Background

Bone-seeking radiopharmaceuticals can deposit radiation selectively to some osteosarcoma tumours because of the bone-forming nature of this cancer.

Objectives

This is the first report of using 223-radium, an alpha-emitting calcium analogue with a high therapeutic index, in combination therapy with other agents in 15 patients with metastatic osteoblastic osteosarcoma.

Methods

Candidates for alpha-radiotherapy if ^99mTc-MDP bone scan had avid bone-forming lesions and no therapy of higher priority (eg, definitive surgery). Monthly 223-radium infusions (1.49 μCi/kg or 55.13 kBq/kg) were given.

Results

The median infusion number was three and the average time to progression was 4.3 months for this cohort receiving 223-radium+other agents. Agents provided during 223-radium included (1) drugs to reduce skeletal complications: monthly denosumab (n=13) or zolendronate (n=1); (2) agents with antivascular endothelial growth factor activity, pazopanib (n=8) or sorafenib (n=1), (3) alkylating agents: oral cyclophosphamide (n=1) or ifosfamide, given as a 14-day continuous infusion (n=1, two cycles), (4) high-dose methotrexate (n=1), pegylated liposomal doxorubicin (n=1); and (5) two other combinations: nivolumab and everolimus (n=1) and rapamycin and auranofin (n=1). Radiation therapy, including stereotactic body radiotherapy (SBRT), was also given to 11 patients concurrently with 223-radium (n=2), after 223-radium completion (n=3), or both concurrently and then sequentially for other sites (n=6). After 223-radium infusions, patients without RT had a median overall survival of 4.3 months compared with those with SBRT and/or RT, who had a median overall survival of 13.5 months.

Conclusion Although only 1/15 of patients with osteoblastic osteosarcoma still remain alive after 223-radium, overall survival

Sanjie Yiliu Formula Inhibits Colorectal Cancer Growth by Suppression of Proliferation and Induction of Apoptosis

Colorectal cancer (CRC) is one of the most common malignancies worldwide. As current therapies toward CRC, including chemotherapy and radiotherapy, pose limitations, such as multidrug resistance (MDR) as well as the intrinsic and potential cytotoxic effects, necessitating to find more effective treatment options with fewer side effects, traditional Chinese medicine (TCM) has an advantage in complementary therapies. In the present study, 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assays), trypan blue staining, colony formation, 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining, cell cycle determination, and Annexin V-FITC/PI staining were used to examine the efficacy of Sanjie Yiliu Formula (SJYLF) against CRC proliferation and to investigate its underlying molecular mechanisms through protein expression of various proapoptotic factors by quantitative polymerase chain reaction (q-PCR) and Western blotting. This four-herb-TCM SJYLF can be suggested as one of the decoctions clinically effective in late-stage cancer treatment. Our results suggest that SJYLF robustly decreased the viability of only CRC cell lines (HCT-8, SW-480, HT-29, and DLD-1) and not the normal human kidney cells (HK-2). Moreover, SJYLF significantly suppressed proliferation and induced apoptosis in HCT-8 and downregulated cyclin D1, CDK4, and BCL-2, while Bax expression was upregulated at both mRNA and protein expression levels.

In vivo fermentation production of humanized noncoding RNAs carrying payload miRNAs for targeted anticancer therapy

Rationale: Noncoding RNAs (ncRNAs) such as microRNAs (miRs or miRNAs) play important roles in the control of cellular processes through posttranscriptional gene regulation. However, ncRNA research is limited to utilizing RNA agents synthesized in vitro. Recombinant RNAs produced and folded in living cells shall better recapitulate biologic RNAs.

Methods: Herein, we developed a novel platform for in vivo fermentation production of humanized recombinant ncRNA molecules, namely hBERAs, carrying payload miRNAs or siRNAs. Target hBERAs were purified by anion exchange FPLC method. Functions of hBERA/miRNAs were investigated in human carcinoma cells and antitumor activities were determined in orthotopic osteosarcoma xenograft spontaneous lung metastasis mouse models.

Results: Proper human tRNAs were identified to couple with optimal hsa-pre-miR-34a as new fully-humanized ncRNA carriers to accommodate warhead miRNAs or siRNAs. A group of 30 target hBERAs were all heterogeneously overexpressed (each accounting for >40% of total bacterial RNA), which facilitated large-scale production (8-31 mg of individual hBERAs from 1L bacterial culture). Model hBERA/miR-34a-5p and miR-124-3p were selectively processed to warhead miRNAs in human carcinoma cells to modulate target gene expression, enhance apoptosis and inhibit invasiveness. In addition, bioengineered miR-34a-5p and miR-124-3p agents both reduced orthotopic osteosarcoma xenograft tumor growth and spontaneous pulmonary metastases significantly.

Conclusion: This novel ncRNA bioengineering technology and resulting recombinant ncRNAs are unique additions to conventional technologies and tools for basic research and drug development.

Diffusion-weighted imaging in differentiating mid-course responders to chemotherapy for long-bone osteosarcoma compared to the histologic response: an update

BACKGROUND

Diffusion-weighted imaging (DWI) has been described to correlate with tumoural necrosis in response to preoperative chemotherapy for osteosarcoma.

OBJECTIVE

To assess the accuracy of DWI in evaluating the response to neoadjuvant chemotherapy at the mid-course treatment of long-bone osteosarcoma and in predicting survival.

MATERIALS AND METHODS

We conducted a prospective single-centre study over a continuous period of 11 years. Consecutive patients younger than 20 years treated with a neoadjuvant regimen for peripheral conventional osteosarcoma were eligible for inclusion. Magnetic resonance imaging (MRI) with DWI was performed at diagnosis, and mid- and end-course chemotherapy with mean apparent diffusion coefficients (ADC) calculated at each time point. A percentage less than or equal to 10% of the viable residual tissue at the histological analysis of the surgical specimen was defined as a good responder to chemotherapy. Survival comparisons were calculated using the Kaplan-Meier method. Uni- and multivariate analyses with ADC change were performed by Cox modelling. This is an expansion and update of our previous work.

RESULTS

Twenty-six patients between the ages of 4.8 and 19.6 years were included, of whom 14 were good responders. At mid-course chemotherapy, good responders had significantly higher mean ADC values (P=0.046) and a higher increase in ADC (P=0.015) than poor responders. The ADC change from diagnosis to mid-course MRI did not appear to be a prognosticator of survival and did not impact survival rates of both groups.

CONCLUSION

DWI at mid-course preoperative chemotherapy for osteosarcoma should be considered to evaluate the degree of histological necrosis and to predict survival. The anticipation of a response to neoadjuvant treatment by DWI may have potential implications on preoperative management.

Effects of Iron Chelation in Osteosarcoma

BACKGROUND

Osteosarcoma is an aggressive bone tumor. It represents the principal cause of cancer-associated death in children. Considering the recent findings on the role of iron in cancer, iron chelation has been investigated for its antineoplastic properties in many tumors. Deferasirox is the most used iron chelator compound and in previous studies showed an anticancer effect in hematologic and solid malignancies. Eltrombopag is a Thrombopoietin receptor used in thrombocytopenia that also binds and mobilize iron. It demonstrated an effect on iron overload conditions and also in contrasting cancer cell proliferation.

OBJECTIVE

We analyzed the effects of deferasirox and eltrombopag in human osteosarcoma cells in an attempt to identify other therapeutic approaches for this tumor.

METHODS

We cultured and treated with deferasirox and Eltrombopag, alone and in combination, two human osteosarcoma cell lines, MG63 and 143B. After 72h exposure, we performed RTqPCR, Western Blotting, Iron Assay and cytofluorimetric assays to evaluate the effect on viability, apoptosis, cell cycle progression and ROS production.

RESULTS

The iron-chelating properties of the two compounds are also confirmed in osteosarcoma, but we did not observe any direct effect on tumor progression.

DISCUSSION

We tested deferasirox and eltrombopag, alone and in combination, in human osteosarcoma cells for the first time and demonstrated that their iron-chelating activity does not influence biochemical pathways related to cancer progression and maintenance.

CONCLUSION

Although further investigations on possible effects mediated by cells of the tumor microenvironment could be of great interest, in vitro iron chelation in osteosarcoma does not impair tumor progression.

The potentiality of immunotherapy for sarcomas: a summary of potential predictive biomarkers

Sarcomas are rare and heterogeneous malignant tumors of mesenchymal origin. A total of 25-50% of patients treated with initial curative intent will develop as recurrent and metastatic disease. In the recurrent and metastatic setting, effect of chemotherapy is limited; therefore, more effective therapies are urgently desired. As a brake for activation of T cell, PD-1/PD-L1 plays a crucial role in the progression of tumor by altering status of immune surveillance. Some success has been acquired recently in the use of PD-1/PD-L1 inhibitors for the treatment of several solid tumors, for examples, non-small-cell lung cancer and melanoma. Immunotherapeutic strategies based on PD-1/PD-L1 for sarcomas have also been explored these years. As in other cancers, major challenges are identification of biomarkers to predict response for immunotherapy, optimization of patient's benefit and minimization of side effects. Therefore, we focused on potential biomarkers of immunotherapy for treatment of sarcomas in this review.

In vitro drug sensitivity (IDS) of patient-derived primary osteosarcoma cells as an early predictor of the clinical outcomes of osteosarcoma patients

PURPOSE

Early prediction of clinical response to conventional chemotherapy is a significant factor in determining an overall treatment strategy for osteosarcoma.

METHODS

Cells were extracted from treatment-naïve biopsies from 16 osteosarcoma patients who received a doxorubicin and cisplatin-based neoadjuvant chemotherapy regimen and their sensitivities to doxorubicin and cisplatin were measured as IC50 values. Associations of in vitro drug sensitivity (IDS) levels and clinical outcomes were examined.

RESULTS

Primary osteosarcoma cells responded to doxorubicin and cisplatin with IC50 values of 0.088 ± 0.032 µM and 16.7 ± 8.5 µM, respectively. The patients with a non-metastatic phenotype and surviving patients showed significantly lower IC50 values for both drugs. ROC analysis defined the optimal IC50 cut-off values for doxorubicin (IDS_dox) and cisplatin (IDS_cpt) as 0.05 µM (AUC 0.82) and 14 µM (AUC 0.87), respectively. Survival analysis found significantly longer disease-free survival (DFS, n = 14) and overall survival (OS, n = 16) times in the patients with low IDS_dox (p = 0.0064 for DFS and p = 0.0102 for OS) and low IDS_cpt (p = 0.0204 for DFS and p = 0.0021 for OS). Interestingly, when the patients with low IDS_cpt and those with low IDS_dox were combined (Group 1), significant associations with prolonged DFS (p = 0.0042, C-statistic 0.78) and OS (p = 0.0010, C-statistic 0.79) were found. In this cohort, histological response to neoadjuvant chemotherapy could predict only OS.

CONCLUSIONS

This study indicates that IDS analysis could potentially be a practical, rapid, and reliable technique for predicting clinical outcomes. It could also be used to identify patients for whom conventional chemotherapy is most appropriate and, in the future, help advance personalized therapy.

Specific Small-Molecule NIR-II Fluorescence Imaging of Osteosarcoma and Lung Metastasis

Osteosarcoma is an aggressive tumor of mesenchymal origin that is more likely to spread to the lung than others, with a major impact on patients' prognosis. The optimal imaging method that can reliably detect or exclude pulmonary metastases from osteosarcoma is still scarce. Herein, two homologous types of fluorescent probes CH1055-PEG-PT and CH1055-PEG-Affibody, which show highly promising results for targeting imaging of osteosarcoma and its lung metastasis, respectively, are designed and synthesized. It is found that the NIR-II imaging quality of CH1055-PEG-PT is far superior to that of computed tomography for the early in vivo 143B tumor imaging, and this probe-guided surgery for accurate resection of 143B tumor is further performed. The high-resolution visualization of primary and micrometastatic lung lesions of osteosarcoma by using CH1055-PEG-Affibody is also demonstrated. Therefore, the attractive imaging properties of CH1055-PEG-PT and CH1055-PEG-Affibody, including high levels of uptakes, and high spatial and temporal resolution, open up opportunities for molecular imaging and clinical translation of osteosarcoma and its lung metastasis in the unique second near-infrared window.

Bioengineered miR-328-3p modulates GLUT1-mediated glucose uptake and metabolism to exert synergistic antiproliferative effects with chemotherapeutics

MicroRNAs (miRNAs or miRs) are small noncoding RNAs derived from genome to control target gene expression. Recently we have developed a novel platform permitting high-yield production of bioengineered miRNA agents (BERA). This study is to produce and utilize novel fully-humanized BERA/miR-328-3p molecule (hBERA/miR-328) to delineate the role of miR-328-3p in controlling nutrient uptake essential for cell metabolism. We first demonstrated successful high-level expression of hBERA/miR-328 in bacteria and purification to high degree of homogeneity (>98%). Biologic miR-328-3p prodrug was selectively processed to miR-328-3p to suppress the growth of highly-proliferative human osteosarcoma (OS) cells. Besides glucose transporter protein type 1, gene symbol solute carrier family 2 member 1 (GLUT1/SLC2A1), we identified and verified large neutral amino acid transporter 1, gene symbol solute carrier family 7 member 5 (LAT1/SLC7A5) as a direct target for miR-328-3p. While reduction of LAT1 protein levels by miR-328-3p did not alter homeostasis of amino acids within OS cells, suppression of GLUT1 led to a significantly lower glucose uptake and decline in intracellular levels of glucose and glycolytic metabolite lactate. Moreover, combination treatment with hBERA/miR-328 and cisplatin or doxorubicin exerted a strong synergism in the inhibition of OS cell proliferation. These findings support the utility of novel bioengineered RNA molecules and establish an important role of miR-328-3p in the control of nutrient transport and homeostasis behind cancer metabolism.

Water Extract of Sporoderm-Broken Spores of Ganoderma lucidum Induces Osteosarcoma Apoptosis and Restricts Autophagic Flux

Purpose

Osteosarcoma (OS) is a malignant bone tumor with easy metastasis and poor prognosis. Ganoderma lucidum (G. lucidum), a traditional Chinese medicine, was reported playing a critical role in suppressing multiple tumor progress. So we wanted to investigate the effects and molecular mechanisms of water extract of sporoderm-broken spores of G. lucidum (BSGLWE) on osteosarcoma.

Methods

In vitro, the effects on cell proliferation of BSGLWE in osteosarcoma cells were detected by CCK-8, colony formation assay and flow cytometry; migration ability of osteosarcoma cells was evaluated by cell scratch and transwell assays. Cell apoptosis and autophagy were tested by transmission electron microscopy (TEM). Potential signaling pathways were detected by Western blotting and immunofluorescence. In xenograft orthotopic model, the luminescence intensity measured by an in vivo bioluminescence imaging system, and the expression of related proteins in tumor cells were assessed by IHC analysis.

Results

BSGLWE suppressed the proliferation and migration of osteosarcoma cells in a dose-dependent manner, and osteosarcoma cell cycle progression at the G2/M phase was arrested by the BSGLWE. In addition, increased apoptosis-related protein expression meant BSFLWE induced caspase-dependent apoptosis of osteosarcoma cells. TEM results indicated that BSGLWE promoted the formation of apoptotic bodies and autophagosomes in HOS and U2 cells. Western blotting or immunofluorescence and rescue assay revealed that BSGLWE blocked autophagic flux by inducing initiation of autophagy and increasing autophagosome accumulation of osteosarcoma cells. BSGLWE not only repressed the angiogenesis in the mouse model, but also induced apoptosis and blocked autophagy in vivo.

Conclusion

BSGLWE inhibits osteosarcoma progression.

TIPE1 suppresses osteosarcoma tumor growth by regulating macrophage infiltration

BACKGROUND

Osteosarcoma is the most common primary malignancy of the bone, and macrophages play a promotional role during osteosarcoma development and progression. TIPE1 is known to function as a tumor suppressor in diverse cancers by inducing cell arrest and apoptosis. However, the biological function of TIPE1 in osteosarcoma is still unclear.

PURPOSE

The purpose of this study was to investigate the expression and function of TIPE1 in osteosarcoma.

METHODS

In the present study, TIPE1 expression in osteosarcoma cancer cells was determined by qPCR and western blotting. A subcutaneous tumor model was established to investigate the potential anti-tumor activity of TIPE1 in osteosarcoma. Further, flow cytometry, western blotting, immunofluorescence staining, and ELISA were performed to clarify the underlying mechanism by which TIPE1 regulates growth of osteosarcoma.

RESULTS

Our results suggest that TIPE1 is downregulated in osteosarcoma cancer cells, and ectopic expression TIPE1 significantly inhibited osteosarcoma tumor growth in vivo. Furthermore, TIPE1 inhibits the infiltration of macrophages in osteosarcoma tumor by suppressing MCP-1 expression in osteosarcoma cells. Further in vivo study revealed that inhibition of MCP-1/CCR2 axis by Bindarit blocked the inhibitory effect of TIPE1 on osteosarcoma growth.

CONCLUSION

Collectively, our results demonstrate the anti-tumor role of TIPE1 in osteosarcoma and reveal a novel therapy target for osteosarcoma.

Co-targeting of DNA, RNA, and protein molecules provides optimal outcomes for treating osteosarcoma and pulmonary metastasis in spontaneous and experimental metastasis mouse models

Metastasis is a major cause of mortality for cancer patients and remains as the greatest challenge in cancer therapy. Driven by multiple factors, metastasis may not be controlled by the inhibition of single target. This study was aimed at assessing the hypothesis that drugs could be rationally combined to co-target critical DNA, RNA and protein molecules to achieve saturation attack against metastasis. Independent actions of the model drugs DNA-intercalating doxorubicin, RNA-interfering miR-34a and protein-inhibiting sorafenib on DNA replication, RNA translation and protein kinase signaling in highly metastatic, human osteosarcoma 143B cells were demonstrated by the increase of? H2A.X foci formation, reduction of c-MET expression and inhibition of Erk1/2 phosphorylation, respectively, and optimal effects were found for triple-drug combination. Consequently, triple-drug treatment showed a strong synergism in suppressing 143B cell proliferation and the greatest effects in reducing cell invasion. Compared to single- and dual-drug treatment, triple-drug therapy suppressed pulmonary metastases and orthotopic osteosarcoma progression to significantly greater degrees in orthotopic osteosarcoma xenograft/spontaneous metastases mouse models, while none showed significant toxicity. In addition, triple-drug therapy improved the overall survival to the greatest extent in experimental metastases mouse models. These findings demonstrate co-targeting of DNA, RNA and protein molecules as a novel therapeutic strategy for the treatment of metastasis.

Bioengineered NRF2-siRNA Is Effective to Interfere with NRF2 Pathways and Improve Chemosensitivity of Human Cancer Cells

The nuclear factor (erythroid-derived 2)-like 2 (NRF2) is a transcription factor in the regulation of many oxidative enzymes and efflux transporters critical for oxidative stress and cellular defense against xenobiotics. NRF2 is dysregulated in patient osteosarcoma (OS) tissues and correlates with therapeutic outcomes. Nevertheless, research on the NRF2 regulatory pathways and its potential as a therapeutic target is limited to the use of synthetic small interfering RNA (siRNA) carrying extensive artificial modifications. Herein, we report successful high-level expression of recombinant siRNA against NRF2 in Escherichia coli using our newly established noncoding RNA bioengineering technology, which was purified to >99% homogeneity using an anion-exchange fast protein liquid chromatography method. Bioengineered NRF2-siRNA was able to significantly knock down NRF2 mRNA and protein levels in human OS 143B and MG63 cells, and subsequently suppressed the expression of NRF2-regulated oxidative enzymes [heme oxygenase-1 and NAD(P)H:quinone oxidoreductase 1] and elevated intracellular levels of reactive oxygen species. In addition, recombinant NRF2-siRNA was effective to sensitize both 143B and MG63 cells to doxorubicin, cisplatin, and sorafenib, which was associated with significant downregulation of NRF2-targeted ATP-binding cassette (ABC) efflux transporters (ABCC3, ABCC4, and ABCG2). These findings support that targeting NRF2 signaling pathways may improve the sensitivity of cancer cells to chemotherapy, and bioengineered siRNA molecules should be added to current tools for related research.

pH-responsive mesoporous ZSM-5 zeolites/chitosan core-shell nanodisks loaded with doxorubicin against osteosarcoma

Oral or intravenous chemotherapy is an important strategy to treat metastatic cancer, but it may cause systemic toxicity for healthy tissue. Herein, we for the first time fabricated mesoporous ZSM-5 zeolites/chitosan core-shell nanodisks loaded with doxorubicin (ZSM-5/CS/DOX) as drug delivery systems against osteosarcoma. The mesoporous ZSM-5 zeolites exhibited disk-like shapes with thicknesses of 100nm and diameters of 300nm, and the mesopores with pore sizes of 3.75nm were originated from desilication treatment. The pH-responsive ZSM-5/CS/DOX nanodisks possessed a great drug loading efficiency of 97.7%, and their controlled release trends of DOX were fitted well with the Korsmeyer-Peppas model. The DOX could be efficiently released the ZSM-5/CS/DOX nanodisks after cellular endocytosis and induced cancer cells apoptosis. Moreover, the pH-responsive drug carriers led to efficient tumor inhibition with low side effects, especially cardiac toxicity, as confirmed by pharmacokinetic study, serological examination and H&E staining assays. Therefore, the ZSM-5/CS/DOX nanodisks are a promising pH-responsive drug carrier for targeted cancer therapy.

MicroRNAs as a novel class of diagnostic biomarkers for the detection of osteosarcoma: a meta-analysis

MicroRNAs (miRNAs) have been considered as promising diagnostic biomarkers for many diseases, especially for cancers. Numerous studies have reported the value of miRNAs in the diagnosis of osteosarcoma (OS), but the results vary greatly across different studies. Therefore, we conducted this meta-analysis to assess the prospective diagnostic value of miRNAs in diagnosing OS. All relevant articles from prior to July 28, 2017 were selected from PubMed, EMBASE, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, and Wan-fang databases. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was performed to assess the quality of each article. A random-effects model was used to pool the sensitivity and specificity of the positive likelihood ratio (PLR), negative likelihood ratio (NLR) and, diagnostic odds ratio (DOR) together with the area under the curve (AUC) to evaluate diagnostic values. Seventeen studies comprising 2,214 OS patients and 1,534 healthy humans were included in our meta-analysis. The pooled estimations indicated that the miRNAs had a high accuracy for diagnosing OS, with a sensitivity of 0.82, specificity of 0.88, PLR of 10.96, NLR of 0.20, DOR of 54.55, and AUC of 0.93. Twenty-five miRNAs were differentially expressed in OS, including 17 upregulated and 8 downregulated. These miRNAs were correlated with survival time, tumor size, cell differentiation, tumor node metastasis staging, metastasis, tumor/cell invasion, pathological type, and response to radiotherapy and chemotherapy. Several different miRNAs are expressed in OS, and some of them might be potential biomarkers for the early diagnosis of OS.

Natural compounds targeting major cell signaling pathways: a novel paradigm for osteosarcoma therapy

Osteosarcoma is the most common primary bone cancer affecting children and adolescents worldwide. Despite an incidence of three cases per million annually, it accounts for an inordinate amount of morbidity and mortality. While the use of chemotherapy (cisplatin, doxorubicin, and methotrexate) in the last century initially resulted in marginal improvement in survival over surgery alone, survival has not improved further in the past four decades. Patients with metastatic osteosarcoma have an especially poor prognosis, with only 30% overall survival. Hence, there is a substantial need for new therapies. The inability to control the metastatic progression of this localized cancer stems from a lack of complete knowledge of the biology of osteosarcoma. Consequently, there has been an aggressive undertaking of scientific investigation of various signaling pathways that could be instrumental in understanding the pathogenesis of osteosarcoma. Here, we review these cancer signaling pathways, including Notch, Wnt, Hedgehog, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT, and JAK/STAT, and their specific role in osteosarcoma. In addition, we highlight numerous natural compounds that have been documented to target these pathways effectively, including curcumin, diallyl trisulfide, resveratrol, apigenin, cyclopamine, and sulforaphane. We elucidate through references that these natural compounds can induce cancer signaling pathway manipulation and possibly facilitate new treatment modalities for osteosarcoma.

Outcomes of chest wall resections in pediatric sarcoma patients

PURPOSE

Chest wall tumors in pediatric patients are rare. This study evaluates outcomes in pediatric patients who have undergone chest wall resections secondary to sarcomas.

METHODS

A retrospective review was performed for patients <19years old who underwent chest wall resections for sarcoma 1999-2014 at the University of Texas MD Anderson Cancer Center.

RESULTS

Of 44 patients, Ewing's sarcoma (n=18) and osteosarcoma (n=16) were most common. Other sarcomas included synovial sarcoma, chondrosarcoma, and rhabdomyosarcoma. Gore-Tex® or a Marlex™ mesh and methyl methacrylate sandwich was used in 22 patients, and 9 children did not require reconstruction. Twenty-four (54.5%) patients had normal activity, 3 (6.8%) had occasional discomfort, 2 (4.5%) had pain impairing function, 7 (15.9%) required medication or physical therapy for impairment, and 8 (18.2%) needed additional surgery. Five children (11.4%) developed scoliosis, and all of these patients had posterior rib tumors. Median overall survival for the entire cohort was 41.9±11.82months. Histology (p=0.003), location of tumor on the ribs (p=0.007), and surgical margins (p=0.011) were significantly associated with overall survival. Tumors on the middle and posterior (p=0.003) portions of the ribs had a lower chance of death.

CONCLUSION

Scoliosis is more common in posterior rib resections. Histology, location of the tumor, and surgical margins impact survival, but, type of reconstruction does not.

LEVEL OF EVIDENCE

III.

TYPE OF STUDY

Treatment Study.

The iron chelator Dp44mT suppresses osteosarcoma's proliferation, invasion and migration: in vitro and in vivo

Di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), the novel iron chelator, has been reported to inhibit the tumorigenesis and progression of various cancer cells, including neuroblastoma, neuroepithelioma and prostate cancer. However, whether Dp44mT has anticancer effects in osteosarcoma is still unknown. Here, we investigated the antitumor action of Dp44mT in osteosarcoma and its underlying mechanisms. A human osteosarcoma 143B cell line in vitro and 143B xenograft in nude mice in vivo were utilized, the anticancer effects of Dp44mT were examined through methods of MTT assay, transwell, wound healing assay, flow cytometry, western blot, immunohistochemistry and H&E staining. We showed that Dp44mT inhibits cell proliferation, invasion and migration in vitro. In addition, flow cytometry further illustrated that Dp44mT suppression of 143B cell proliferation, invasion and migration were partially due to induction of cell apoptosis, cell cycle arrest in S phase and ROS production. Also in vitro and in vivo, the expression levels of Bcl2, Bax, Caspase3, Caspase9, LC3-II, β-catenin and its downstream targets such as C-myc and Cyclin D1 demonstrated that cell apoptosis and autophagy, as well as Wnt/β-catenin pathway were involved in Dp44mT induced osteosarcoma suppression. The Dp44mT inhibition of osteosarcoma was further verified via animal models. The findings indicated that in vivo Dp44mT showed a significant reduction in the 143B xenograft tumor growth and metastasis. In conclusion, our data demonstrated that Dp44mT has effective anticancer capability in osteosarcoma and that may represent a promising treatment strategy for osteosarcoma.

Novel insights and therapeutic interventions for pediatric osteosarcoma

High-grade osteosarcomas are the most common primary malignant tumors of bone. With complete surgical resection and multi-agent chemotherapy up to 70% of patients with high-grade osteosarcomas and localized extremity tumors can become long-term survivors. The prognosis, however, is poor for patients with nonresectable, primary metastatic or relapsed disease. Outcome is essentially unchanged for three decades. Herein, we describe selected novel insights into the genomics, biology and immunology of the disease and discuss selected strategies, which hold promise to overcome the current stagnation in the therapeutic success in childhood osteosarcoma.

Mitochondria-Targeted Doxorubicin: A New Therapeutic Strategy against Doxorubicin-Resistant Osteosarcoma

Doxorubicin is one of the leading drugs for osteosarcoma standard chemotherapy. A total of 40% to 45% of high-grade osteosarcoma patients are unresponsive, or only partially responsive, to doxorubicin (Dox), due to the overexpression of the drug efflux transporter ABCB1/P-glycoprotein (Pgp). The aim of this work is to improve Dox-based regimens in resistant osteosarcomas. We used a chemically modified mitochondria-targeted Dox (mtDox) against Pgp-overexpressing osteosarcomas with increased resistance to Dox. Unlike Dox, mtDox accumulated at significant levels intracellularly, exerted cytotoxic activity, and induced necrotic and immunogenic cell death in Dox-resistant/Pgp-overexpressing cells, fully reproducing the activities exerted by anthracyclines in drug-sensitive tumors. mtDox reduced tumor growth and cell proliferation, increased apoptosis, primed tumor cells for recognition by the host immune system, and was less cardiotoxic than Dox in preclinical models of drug-resistant osteosarcoma. The increase in Dox resistance was paralleled by a progressive upregulation of mitochondrial metabolism. By widely modulating the expression of mitochondria-related genes, mtDox decreased mitochondrial biogenesis, the import of proteins and metabolites within mitochondria, mitochondrial metabolism, and the synthesis of ATP. These events were paralleled by increased reactive oxygen species production, mitochondrial depolarization, and mitochondria-dependent apoptosis in resistant osteosarcoma cells, where Dox was completely ineffective. We propose mtDox as a new effective agent with a safer toxicity profile compared with Dox that may be effective for the treatment of Dox-resistant/Pgp-positive osteosarcoma patients, who strongly need alternative and innovative treatment strategies. Mol Cancer Ther; 15(11); 2640-52. ©2016 AACR.

Pediatric Malignant Bone Tumors: A Review and Update on Current Challenges, and Emerging Drug Targets

Osteosarcoma (OS) and the Ewing sarcoma family of tumors (ESFT) are the most common malignant bone tumors in children and adolescents. While significant improvements in survival have been seen in other pediatric malignancies the treatment and prognosis for pediatric bone tumors has remained unchanged for the past 3 decades. This review and update of pediatric malignant bone tumors will provide a general overview of osteosarcoma and the Ewing sarcoma family of tumors, discuss bone tumor genomics, current challenges, and emerging drug targets.

Genetically engineered pre-microRNA-34a prodrug suppresses orthotopic osteosarcoma xenograft tumor growth via the induction of apoptosis and cell cycle arrest

Osteosarcoma (OS) is the most common primary malignant bone tumor in children, and microRNA-34a (miR-34a) replacement therapy represents a new treatment strategy. This study was to define the effectiveness and safety profiles of a novel bioengineered miR-34a prodrug in orthotopic OS xenograft tumor mouse model. Highly purified pre-miR-34a prodrug significantly inhibited the proliferation of human 143B and MG-63 cells in a dose dependent manner and to much greater degrees than controls, which was attributed to induction of apoptosis and G2 cell cycle arrest. Inhibition of OS cell growth and invasion were associated with release of high levels of mature miR-34a from pre-miR-34a prodrug and consequently reduction of protein levels of many miR-34a target genes including SIRT1, BCL2, c-MET, and CDK6. Furthermore, intravenous administration of in vivo-jetPEI formulated miR-34a prodrug significantly reduced OS tumor growth in orthotopic xenograft mouse models. In addition, mouse blood chemistry profiles indicated that therapeutic doses of bioengineered miR-34a prodrug were well tolerated in these animals. The results demonstrated that bioengineered miR-34a prodrug was effective to control OS tumor growth which involved the induction of apoptosis and cell cycle arrest, supporting the development of bioengineered RNAs as a novel class of large molecule therapeutic agents.

Present Advances and Future Perspectives of Molecular Targeted Therapy for Osteosarcoma

Osteosarcoma (OS) is a bone cancer mostly occurring in pediatric population. Current treatment regime of surgery and intensive chemotherapy could cure about 60%-75% patients with primary osteosarcoma, however only 15% to 30% can be cured when pulmonary metastasis or relapse has taken place. Hence, novel precise OS-targeting therapies are being developed with the hope of addressing this issue. This review summarizes the current development of molecular mechanisms and targets for osteosarcoma. Therapies that target these mechanisms with updated information on clinical trials are also reviewed. Meanwhile, we further discuss novel therapeutic targets and OS-targeting drug delivery systems. In conclusion, a full insight in OS pathogenesis and OS-targeting strategies would help us explore novel targeted therapies for metastatic osteosarcoma.

Update on Survival in Osteosarcoma

Osteosarcoma is the most common primary bone malignancy in children. Treatment has evolved to include systemic chemotherapy and local control surgery. Although survival improved initially in a drastic fashion with this approach, recent decades have seen little to no further gains in this area. Limb salvage surgery evolved with effective chemotherapy and advances in imaging, and continues to improve in the recent era. This article serves as a review of survival in high-grade osteosarcoma: prognostic factors, advances in chemotherapy and surgery, late effects of chemotherapy and surgery in survivors, and future directions.

Combination therapy with bioengineered miR-34a prodrug and doxorubicin synergistically suppresses osteosarcoma growth

Osteosarcoma (OS) is the most common form of primary malignant bone tumor and prevalent among children and young adults. Recently we have established a novel approach to bioengineering large quantity of microRNA-34a (miR-34a) prodrug for miRNA replacement therapy. This study is to evaluate combination treatment with miR-34a prodrug and doxorubicin, which may synergistically suppress human OS cell growth via RNA interference and DNA intercalation. Synergistic effects were indeed obvious between miR-34a prodrug and doxorubicin for the suppression of OS cell proliferation, as defined by Chou-Talalay method. The strongest antiproliferative synergism was achieved when both agents were administered simultaneously to the cells at early stage, which was associated with much greater degrees of late apoptosis, necrosis, and G2 cell cycle arrest. Alteration of OS cellular processes and invasion capacity was linked to the reduction of protein levels of miR-34a targeted (proto-)oncogenes including SIRT1, c-MET, and CDK6. Moreover, orthotopic OS xenograft tumor growth was repressed to a significantly greater degree in mouse models when miR-34a prodrug and doxorubicin were co-administered intravenously. In addition, multiple doses of miR-34a prodrug and doxorubicin had no or minimal effects on mouse blood chemistry profiles. The results demonstrate that combination of doxorubicin chemotherapy and miR-34a replacement therapy produces synergistic antiproliferative effects and it is more effective than monotherapy in suppressing OS xenograft tumor growth. These findings support the development of mechanism-based combination therapy to combat OS and bioengineered miR-34a prodrug represents a new natural miRNA agent.

Targeting protein kinases to reverse multidrug resistance in sarcoma

Sarcomas are a group of cancers that arise from transformed cells of mesenchymal origin. They can be classified into over 50 subtypes, accounting for approximately 1% of adult and 15% of pediatric cancers. Wide surgical resection, radiotherapy, and chemotherapy are the most common treatments for the majority of sarcomas. Among these therapies, chemotherapy can palliate symptoms and prolong life for some sarcoma patients. However, sarcoma cells can have intrinsic or acquired resistance after treatment with chemotherapeutics drugs, leading to the development of multidrug resistance (MDR). MDR attenuates the efficacy of anticancer drugs and results in treatment failure for sarcomas. Therefore, overcoming MDR is an unmet need for sarcoma therapy. Certain protein kinases demonstrate aberrant expression and/or activity in sarcoma cells, which have been found to be involved in the regulation of sarcoma cell progression, such as cell cycle, apoptosis, and survival. Inhibiting these protein kinases may not only decrease the proliferation and growth of sarcoma cells, but also reverse their resistance to chemotherapeutic drugs to subsequently reduce the doses of anticancer drugs and decrease drug side-effects. The discovery of novel strategies targeting protein kinases opens a door to a new area of sarcoma research and provides insight into the mechanisms of MDR in chemotherapy. This review will focus on the recent studies in targeting protein kinase to reverse chemotherapeutic drug resistance in sarcoma.