What is the best clinical approach to recurrent/refractory osteosarcoma?

Host-derived growth factors drive ERK phosphorylation and MCL1 expression to promote osteosarcoma cell survival during metastatic lung colonization

PURPOSE

For patients with osteosarcoma, disease-related mortality most often results from lung metastasis-a phenomenon shared with many solid tumors. While established metastatic lesions behave aggressively, very few of the tumor cells that reach the lung will survive. By identifying mechanisms that facilitate survival of disseminated tumor cells, we can develop therapeutic strategies that prevent and treat metastasis.

METHODS

We analyzed single cell RNA-sequencing (scRNAseq) data from murine metastasis-bearing lungs to interrogate changes in both host and tumor cells during colonization. We used these data to elucidate pathways that become activated in cells that survive dissemination and identify candidate host-derived signals that drive activation. We validated these findings through live cell reporter systems, immunocytochemistry, and fluorescent immunohistochemistry. We then validated the functional relevance of key candidates using pharmacologic inhibition in models of metastatic osteosarcoma.

RESULTS

Expression patterns suggest that the MAPK pathway is significantly elevated in early and established metastases. MAPK activity correlates with expression of anti-apoptotic genes, especially MCL1. Niche cells produce growth factors that increase ERK phosphorylation and MCL1 expression in tumor cells. Both early and established metastases are vulnerable to MCL1 inhibition, but not MEK inhibition in vivo. Combining MCL1 inhibition with chemotherapy both prevented colonization and eliminated established metastases in murine models of osteosarcoma.

CONCLUSION

Niche-derived growth factors drive MAPK activity and MCL1 expression in osteosarcoma, promoting metastatic colonization. Although later metastases produce less MCL1, they remain dependent on it. MCL1 is a promising target for clinical trials in both human and canine patients.

Does primary tumor resection improve survival for patients with sarcomas of pelvic bones, sacrum, and coccyx who have metastasis at diagnosis ?

BACKGROUND

Recent studies demonstrated that primary tumor resection (PTR) improves survival of patients with metastatic bone sarcomas. However, it remains quite unclear regarding the role of PTR in the treatment of sarcomas of pelvic bones with synchronous metastasis at diagnosis.

METHODS

Using the Surveillance, Epidemiology, and End Results Program, we enrolled a total of 385 patients with sarcomas of pelvic bones, sacrum, and coccyx who have metastasis at initial diagnosis, including 139 patients with osteosarcoma, 176 with Ewing sarcoma, and 70 with chondrosarcoma. Association between PTR and disease-specific survival (DSS) were investigated using the univariable and multivariable Cox regression models. Hazard ratio (HR) and 95% confidence interval (CI) were reported. Representative institutional PTR strategies and clinical outcomes for patients with metastatic pelvic sarcomas from our cancer center were displayed.

RESULTS

The usage rate of PTR was 28.1% (39/139) in osteosarcoma, 13.6% (24/176) in Ewing sarcoma, and 41.4% (29/70) in chondrosarcoma with synchronous metastatic lesions. PTR was not associated with an improved DSS for metastatic pelvic osteosarcoma (HR = 0.686, 95% CI = 0.430 ~ 1.094, P = 0.113) and Ewing sarcoma (HR = 0.580, 95% CI = 0.291 ~ 1.154, P = 0.121). The use of PTR was associated with an improved DSS for metastatic pelvic chondrosarcoma (HR = 0.464, 95% CI = 0.225 ~ 0.954, P = 0.037).

CONCLUSION

Primary lesion resection may provide a survival benefit for metastatic chondrosarcoma, but not for osteosarcoma and Ewing sarcoma of pelvic bones, sacrum, and coccyx. This population-based study recommends an active surgical intervention for metastatic chondrosarcoma while non-surgical treatment for metastatic osteosarcoma and Ewing sarcoma of the pelvis in terms of survival improvement.

A systematic review of recent phase-II trials in refractory or recurrent osteosarcoma: Can we inform future trial design?

BACKGROUND/OBJECTIVE

To analyze changes in recurrent/refractory osteosarcoma phase II trials over time to inform future trials in this population with poor prognosis.

METHODS

A systematic review of trials registered on trial registries between 01/01/2017-14/02/2022. Comparison of 98 trials identified between 2003 and 2016. Publication search/analysis for both periods, last update on 01/12/2022.

RESULTS

Between 2017 and 2022, 71 phase-II trials met our selection criteria (19 osteosarcoma-specific trials, 14 solid tumor trials with and 38 trials without an osteosarcoma-specific stratum). The trial number increased over time: 13.9 versus 7 trials/year (p = 0.06). Monotherapy remained the predominant treatment (62% vs. 62%, p = 1). Targeted therapies were increasingly evaluated (66% vs. 41%, P = 0.001). Heterogeneity persisted in the trial characteristics. The inclusion criteria were measurable disease (75%), evaluable disease (14%), and surgical remission (11%). 82% of the trials included pediatric or adolescent patients. Biomarker-driven trials accounted for 25% of the total trials. The survival endpoint use (rather than response) slightly increased (40% versus 31%), but the study H1/H0 hypotheses remained heterogeneous. Single-arm designs predominated over multiarm trials (n = 7). Available efficacy data on 1361 osteosarcoma patients in 58 trials remained disappointing, even though 21% of these trials were considered positive, predominantly those evaluating multi-targeted kinase inhibitors.

CONCLUSION

Despite observed changes in trial design and an increased number of trials investigating new therapies, high heterogeneity remained with respect to patient selection, study design, primary endpoints, and statistical hypotheses in recently registered phase II trials for osteosarcoma. Continued optimization of trial design informed by a deeper biological understanding should strengthen the development of new therapies.

Integrated multiomic analysis and high-throughput screening reveal potential gene targets and synergetic drug combinations for osteosarcoma therapy

Although great advances have been made over the past decades, therapeutics for osteosarcoma are quite limited. We performed long-read RNA sequencing and tandem mass tag (TMT)-based quantitative proteome on osteosarcoma and the adjacent normal tissues, next-generation sequencing (NGS) on paired osteosarcoma samples before and after neoadjuvant chemotherapy (NACT), and high-throughput drug combination screen on osteosarcoma cell lines. Single-cell RNA sequencing data were analyzed to reveal the heterogeneity of potential therapeutic target genes. Additionally, we clarified the synergistic mechanisms of doxorubicin (DOX) and HDACs inhibitors for osteosarcoma treatment. Consequently, we identified 2535 osteosarcoma-specific genes and several alternative splicing (AS) events with osteosarcoma specificity and/or patient heterogeneity. Hundreds of potential therapeutic targets were identified among them, which showed the core regulatory roles in osteosarcoma. We also identified 215 inhibitory drugs and 236 synergistic drug combinations for osteosarcoma treatment. More interestingly, the multiomic analysis pointed out the pivotal role of HDAC1 and TOP2A in osteosarcoma. HDAC inhibitors synergized with DOX to suppress osteosarcoma both in vitro and in vivo. Mechanistically, HDAC inhibitors synergized with DOX by downregulating SP1 to transcriptionally modulate TOP2A expression. This study provided a comprehensive view of molecular features, therapeutic targets, and synergistic drug combinations for osteosarcoma.

LncRNA MALAT1-related signaling pathways in osteosarcoma

Osteosarcoma (OS) is a common and malignant form of bone cancer, which affects children and young adults. OS is identified by osteogenic differentiation and metastasis. However, the exact molecular mechanism of OS development and progression is still unclear. Recently, long non-coding RNAs (lncRNA) have been proven to regulate OS proliferation and drug resistance. LncRNAs are longer than 200 nucleotides that represent the extensive applications in the processing of pre-mRNA and the pathogenesis of human diseases. Metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) is a well-known lncRNA known as a transcriptional and translational regulator. The aberrant expression of MALAT1 has been shown in several human cancers. The high level of MALAT1 is involved in OS cell growth and tumorigenicity by targeting several signaling pathways and miRNAs. Hence, MALAT1 might be a suitable approach for OS diagnosis and treatment. In this review, we will summarize the role of lncRNA MALAT1 in the pathophysiology of OS.

Nitazoxanide inhibits osteosarcoma cells growth and metastasis by suppressing AKT/mTOR and Wnt/β-catenin signaling pathways

Osteosarcoma (OS) is the most prevalent malignant bone tumor with poor prognosis. Developing new drugs for the chemotherapy of OS has been a focal point and a major obstacle of OS treatment. Nitazoxanide (NTZ), a conventional anti-parasitic agent, has got increasingly noticed because of its favorable antitumor potential. Herein, we investigated the effect of NTZ on human OS cells in vitro and in vivo. The results obtained in vitro showed that NTZ inhibited the proliferation, migration and invasion, arrested cell cycle at G1 phase, while induced apoptosis of OS cells. Mechanistically, NTZ suppressed the activity of AKT/mTOR and Wnt/β-catenin signaling pathways of OS cells. Consistent with the results in vitro, orthotopic implantation model of 143B OS cells further confirmed that NTZ inhibited OS cells growth and lung metastasis in vivo. Notably, NTZ caused no apparent damage to normal cells/tissues. In conclusion, NTZ may inhibit tumor growth and metastasis of human OS cells through suppressing AKT/mTOR and Wnt/β-catenin signaling pathways.

Successful limb salvage in progressive proximal tibia osteosarcoma following denosumab chemotherapy: A case report

RATIONALE

Osteosarcoma (OS) is a primary malignant bone tumor that originates in the mesenchymal tissue. It is the most common type of pleomorphic tumor occurring in children and adolescents. Currently, there is no established systematic treatment for OS that progresses during standard preoperative chemotherapy.

PATIENT CONCERNS AND DIAGNOSES

We describe a 14-year-old male patient with a 4-month history of pain in the upper right leg. Based on the results of percutaneous biopsy, a diagnosis of OS was made. After admission, the patient was treated with first-line chemotherapy agents. After a single course of treatment, the tumor progressed locally and no limb salvage was feasible.

INTERVENTIONS AND OUTCOMES

Intervention with denosumab combined with chemotherapy led to a significant reduction in tumor volume and ossification of soft tissue, which successfully resulted in limb salvage rather than amputation. The patient showed no evidence of recurrent or distant metastasis at 6-month follow-up.

LESSONS

Treatment with receptor activator of nuclear factor-ĸB ligand inhibitor denosumab combined with standard chemotherapy is effective for advanced OS progressing after chemotherapy. We recommend denosumab therapy for successful limb salvage in patients with high-grade OS associated with osteolytic bone destruction and refractory to preoperative neoadjuvant chemotherapy.

Targeted Delivery of Chemotherapeutic Agents for Osteosarcoma Treatment

Since osteosarcoma (OS) is an aggressive bone cancer with unknown molecular pathways of etiology and pathophysiology, improving patient survival has long been a challenge. The conventional therapy is a complex multidisciplinary management that include radiotherapy, chemotherapy which followed by surgery and then post-operative adjuvant chemotherapy. However, they have severe side effects because the majority of the medicines used have just a minor selectivity for malignant tissue. As a result, treating tumor cells specifically without damaging healthy tissue is currently a primary goal in OS therapy. The coupling of chemotherapeutic drugs with targeting ligands is a unique therapy method for OS that, by active targeting, can overcome the aforementioned hurdles. This review focuses on advances in ligands and chemotherapeutic agents employed in targeted delivery to improve the capacity of active targeting and provide some insight into future therapeutic research for OS.

Influence of Magnetic Scaffold Loading Patterns on their Hyperthermic Potential against Bone Tumors

Magnetic scaffolds have been investigated as promising tools for the interstitial hyperthermia treatment of bone cancers, to control local recurrence by enhancing radio- and chemotherapy effectiveness. The potential of magnetic scaffolds motivates the development of production strategies enabling tunability of the resulting magnetic properties. Within this framework, deposition and drop-casting of magnetic nanoparticles on suitable scaffolds offer advantages such as ease of production and high loading, although these approaches are often associated with a non-uniform final spatial distribution of nanoparticles in the biomaterial. The implications and the influences of nanoparticle distribution on the final therapeutic application have not yet been investigated thoroughly. In this work, poly-caprolactone scaffolds are magnetized by loading them with synthetic magnetic nanoparticles through a drop-casting deposition and tuned to obtain different distributions of magnetic nanoparticles in the biomaterial. The physicochemical properties of the magnetic scaffolds are analyzed. The microstructure and the morphological alterations due to the reworked drop-casting process are evaluated and correlated to static magnetic measurements. THz tomography is used as an innovative investigation technique to derive the spatial distribution of nanoparticles. Finally, multiphysics simulations are used to investigate the influence on the loading patterns on the interstitial bone tumor hyperthermia treatment.

The survival and proliferation of osteosarcoma cells are dependent on the mitochondrial BIG3-PHB2 complex formation

Previous studies reported the critical role of the brefeldin A-inhibited guanine nucleotide exchange protein 3-prohibitin 2 (BIG3-PHB2) complex in modulating estrogen signaling activation in breast cancer cells, yet its pathophysiological roles in osteosarcoma (OS) cells remain elusive. Here, we report a novel function of BIG3-PHB2 in OS malignancy. BIG3-PHB2 complexes were localized mainly in mitochondria in OS cells, unlike in estrogen-dependent breast cancer cells. Depletion of endogenous BIG3 expression by small interfering RNA (siRNA) treatment led to significant inhibition of OS cell growth. Disruption of BIG3-PHB2 complex formation by treatment with specific peptide inhibitor also resulted in significant dose-dependent suppression of OS cell growth, migration, and invasion resulting from G2/M-phase arrest and in PARP cleavage, ultimately leading to PARP-1/apoptosis-inducing factor (AIF) pathway activation-dependent apoptosis in OS cells. Subsequent proteomic and bioinformatic pathway analyses revealed that disruption of the BIG3-PHB2 complex might lead to downregulation of inner mitochondrial membrane protein complex activity. Our findings indicate that the mitochondrial BIG3-PHB2 complex might regulate PARP-1/AIF pathway-dependent apoptosis during OS cell proliferation and progression and that disruption of this complex may be a promising therapeutic strategy for OS.

Anoctamin 5 promotes osteosarcoma development by increasing degradation of Nel-like proteins 1 and 2

Anoctamin 5 (ANO5) is a member of the Anoctamin (ANO) family of calcium-activated chloride channels. Although ANO5 expression is upregulated in various cancers, its role in osteosarcoma remains largely unknown. In this study, bioinformatics analysis, western blot, and immunohistochemical staining revealed that ANO5 was upregulated in osteosarcoma cell lines and osteosarcoma tissues, and ANO5 expression was positively associated with tumor size, tumor grade, and metastasis. Functional experiments demonstrated that inhibition of ANO5 decreased, while ANO5 overexpression increased, osteosarcoma cell proliferation and mobility in vitro. Immunoprecipitation, western blot, and confocal microscopy experiments showed that ANO5 bound to and promoted the degradation of Nel-like proteins 1 (NELL1) and 2 (NELL2). Moreover, a subcutaneous tumor transplantation model revealed that ANO5 knockdown reduced osteosarcoma cell proliferation and increased NELL1 and NELL2 expression in vivo. Finally, rescue experiments showed that knockdown of NELL1 or NELL2 reversed the inhibitory effects of ANO5 knockdown on osteosarcoma cell proliferation and migration. These results demonstrated that upregulation of ANO5 promoted osteosarcoma development by decreasing the stability of the NELL1 and NELL2 proteins and that ANO5 may be an effective target for the treatment of osteosarcoma.

State-of-the-art, approved therapeutics for the pharmacological management of osteosarcoma

Introduction: Advances in the treatment of osteosarcoma (OS) came in the mid-1970s, when adding chemotherapy to surgery significantly improved patient survival. OS outcomes have since plateaued, however, despite exhaustive clinical investigations.Area covered: This review focuses on the most significant recent results of trials (in phases II and III) on localized and metastatic/relapsing OS and offers an overview of new targeted drugs.Expert opinion: Recent findings confirm the MAP (methotrexate, doxorubicin, and cisplatin) regimen as the gold standard for OS patients, also in metastatic cases, and the inefficacy of augmenting or modifying chemotherapy in poor responder patients. Immunotherapy and several tyrosine kinase inhibitors seem to be effective and promising in the treatment of OS. Optimizing the use of active drugs available by personalizing chemotherapies might prove important in the future. We urgently need bench-to-bedside research on OS. This will need to involve the extensive sequencing and immunoprofiling of all resected tumor tissue to find new therapeutic agents, especially for relapsing/metastatic patients. The low incidence of OS, its genomic complexity, and differences within and between tumors combine to complicate efforts to elucidate the biology of this disease. This means that we need to pool the resources of different groups studying OS and support translational research.

Managing axial bone sarcomas in childhood

Introduction: Axial osteosarcoma and Ewing sarcoma are rare, aggressive neoplasms with a worse prognosis than with tumors involving the extremities because they are more likely to be associated with larger tumor volumes, older age, primary metastases, and a poor histological response to chemotherapy. The 5-year OS rates are reportedly in the range of 18-41% for axial osteosarcoma, and 46-64% for Ewing sarcoma.Area covered: The treatment of axial bone tumors is the same as for extremity bone tumors, and includes chemotherapy, surgery and/or radiotherapy.Expert opinion: Local treatment of axial tumors is particularly difficult due to their proximity to neurological and vascular structures, which often makes extensive and en bloc resections impossible without causing significant morbidity. The incidence of local relapse is consequently high, and this is the main issue in the treatment of these tumors. Radiotherapy is an option in the case of surgical resections with close or positive margins, as well as for inoperable tumors. Delivering high doses of RT to the spinal cord can be dangerous. Given the complexity and rarity of these tumors, it is essential for this subset of patients to be treated at selected reference institutions with specific expertise and multidisciplinary skills.

Critical roles of the lncRNA CASC11 in tumor progression and cancer metastasis: The biomarker and therapeutic target potential

The frequency of human suffering from cancer is increasing annually across the globe. This has fueled numerous investigations aimed at the prevention and cure of various cancers. Long non-coding RNA (lncRNA) are known to play a crucial role in cancer. For instance, cancer susceptibility candidate 11 (CASC11), as one of the long non-coding RNAs, has been reported to be overexpressed in various tumors. This review elucidates the mechanism by which lncRNA CASC11 regulates tumors' biological processes and affirms its value as a therapeutic target for tumors. Through systematic analysis and review of relevant articles in PubMed, we revealed the pathophysiological mechanism of CASC11 on the tumor by regulating the biological processes of tumor such as proliferation, autophagy, apoptosis, thereby promoting tumor metastasis. We also revealed the regulatory pathways of CASC11 in different tumors, for instance by acting on a variety of microRNAs, oncogenic proteins, carcinogens, and transcription factors. Consequently, CASC11 regulates cancer proliferation, apoptosis, and invasion by altering the WNT/β-catenin signaling pathway and epithelial–mesenchymal transition (EMT). Furthermore, CASC11 expression has a high pertinence with clinical prognosis, suggesting that it is a potential marker for malignant tumors or a clinical adjuvant therapy in the future.