Tegavivint and the β-Catenin/ALDH Axis in Chemotherapy-Resistant and Metastatic Osteosarcoma

State of the Art Modelling of the Breast Cancer Metastatic Microenvironment: Where Are We?

Metastatic spread of tumour cells to tissues and organs around the body is the most frequent cause of death from breast cancer. This has been modelled mainly using mouse models such as syngeneic mammary cancer or human in mouse xenograft models. These have limitations for modelling human disease progression and cannot easily be used for investigation of drug resistance and novel therapy screening. To complement these approaches, advances are being made in ex vivo and 3D in vitro models, which are becoming progressively better at reliably replicating the tumour microenvironment and will in the future facilitate drug development and screening. These approaches include microfluidics, organ-on-a-chip and use of advanced biomaterials. The relevant tissues to be modelled include those that are frequent and clinically important sites of metastasis such as bone, lung, brain, liver for invasive ductal carcinomas and a distinct set of common metastatic sites for lobular breast cancer. These sites all have challenges to model due to their unique cellular compositions, structure and complexity. The models, particularly in vivo, provide key information on the intricate interactions between cancer cells and the native tissue, and will guide us in producing specific therapies that are helpful in different context of metastasis.

Deciphering chemoresistance in osteosarcoma: Unveiling regulatory mechanisms and function through the lens of noncoding RNA

Osteosarcoma (OS) is a primary malignant bone tumor and is prevalent in children, adolescents, and elderly individuals. It has the characteristics of high invasion and metastasis. Neoadjuvant chemotherapy combined with surgical resection is the most commonly used treatment for OS. However, the efficacy of OS is considerably diminished by chemotherapy resistance. In recent years, noncoding RNAs (ncRNAs), including microRNAs, long noncoding RNAs, and circular RNAs, are hot topics in the field of chemotherapy resistance research. Several studies have demonstrated that ncRNAs are substantially associated with chemoresistance in OS. Thus, the present study overviews the abnormally expressed ncRNAs in OS and the molecular mechanisms involved in chemoresistance, with an emphasis on their function in promoting or inhibiting chemoresistance. ncRNAs are expected to become potential therapeutic targets for overcoming drug resistance and predictive biomarkers in OS, which are of great significance for enhancing the therapeutic effect and improving the prognosis.

Osteosarcoma PDX-Derived Cell Line Models for Preclinical Drug Evaluation Demonstrate Metastasis Inhibition by Dinaciclib through a Genome-Targeted Approach

PURPOSE

Models to study metastatic disease in rare cancers are needed to advance preclinical therapeutics and to gain insight into disease biology. Osteosarcoma is a rare cancer with a complex genomic landscape in which outcomes for patients with metastatic disease are poor. As osteosarcoma genomes are highly heterogeneous, multiple models are needed to fully elucidate key aspects of disease biology and to recapitulate clinically relevant phenotypes.

EXPERIMENTAL DESIGN

Matched patient samples, patient-derived xenografts (PDX), and PDX-derived cell lines were comprehensively evaluated using whole-genome sequencing and RNA sequencing. The in vivo metastatic phenotype of the PDX-derived cell lines was characterized in both an intravenous and an orthotopic murine model. As a proof-of-concept study, we tested the preclinical effectiveness of a cyclin-dependent kinase inhibitor on the growth of metastatic tumors in an orthotopic amputation model.

RESULTS

PDXs and PDX-derived cell lines largely maintained the expression profiles of the patient from which they were derived despite the emergence of whole-genome duplication in a subset of cell lines. The cell lines were heterogeneous in their metastatic capacity, and heterogeneous tissue tropism was observed in both intravenous and orthotopic models. Single-agent dinaciclib was effective at dramatically reducing the metastatic burden.

CONCLUSIONS

The variation in metastasis predilection sites between osteosarcoma PDX-derived cell lines demonstrates their ability to recapitulate the spectrum of the disease observed in patients. We describe here a panel of new osteosarcoma PDX-derived cell lines that we believe will be of wide use to the osteosarcoma research community.

Wnt/β-catenin signaling pathway in the tumor progression of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is an uncommon, aggressive endocrine malignancy with a high rate of recurrence, a poor prognosis, and a propensity for metastasis. Currently, only mitotane has received certification from both the US Food and Drug Administration (FDA) and the European Medicines Agency for the therapy of advanced ACC. However, treatment in the advanced periods of the disorders is ineffective and has serious adverse consequences. Completely surgical excision is the only cure but has failed to effectively improve the survival of advanced patients. The aberrantly activated Wnt/β-catenin pathway is one of the catalysts for adrenocortical carcinogenesis. Research has concentrated on identifying methods that can prevent the stimulation of the Wnt/β-catenin pathway and are safe and advantageous for patients in view of the absence of effective treatments and the frequent alteration of the Wnt/β-catenin pathway in ACC. Comprehending the complex connection between the development of ACC and Wnt/β-catenin signaling is essential for accurate pharmacological targets. In this review, we summarize the potential targets between adrenocortical carcinoma and the Wnt/β-catenin signaling pathway. We analyze the relevant targets of drugs or inhibitors that act on the Wnt pathway. Finally, we provide new insights into how drugs or inhibitors may improve the treatment of ACC.

DLX2 promotes osteosarcoma epithelial-mesenchymal transition and doxorubicin resistance by enhancing HOXC8-CDH2 axis

Metastasis and doxorubicin resistance are challenges in the clinical diagnosis and treatment of osteosarcoma, the mechanisms underlying these phenomena remain unclear. In this study, we found that DLX2 is highly expressed in metastatic osteosarcoma and is closely related to clinical prognosis. Knockdown of DLX2 inhibited tumor proliferation and migration in vitro and inhibited tumor growth in vivo. Mechanistically, we found that DLX2 enhanced the repression of CDH2 transcription by binding to HOXC8, thereby promoting the epithelial-mesenchymal transition in osteosarcoma cells. Through subsequent exploration, we found that targeting DLX2/HOXC8 signaling significantly restores the sensitivity of osteosarcoma cells to doxorubicin. In conclusion, our findings demonstrate that DLX2 may enhance the transcriptional regulation of CDH2 through interacting with HOXC8, which in turn promotes epithelial-mesenchymal transition and doxorubicin resistance in osteosarcoma. These findings hold great potential for clinical application and may guide the development of novel targeted therapies for osteosarcoma.

Research progress in the mechanism and treatment of osteosarcoma

ABSTRACT

Osteosarcoma (OS) is the most common primary malignant bone tumor that more commonly occurs in children and adolescents. The most commonly used treatment for OS is surgery combined with chemotherapy, but the treatment outcomes are typically unsatisfactory. High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS. This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities. Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS. In this review, we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS. We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.

Butyrate enhances erastin-induced ferroptosis of osteosarcoma cells via regulating ATF3/SLC7A11 pathway

Osteosarcoma (OS) is a highly fatal bone tumor characterized by high degree of malignancy and early lung metastasis. Traditional chemotherapy fails in improving the efficacy and survival rate of patients with OS. Butyrate (NaBu) has been reported as a new antitumor drug for inhibiting proliferation and inducing apoptosis in various cancer cells. However, the effect of NaBu on the ferroptosis of OS is still unknown. This study aimed to investigate whether NaBu promotes erastin-induced ferroptosis in OS cells and to uncover the underlying mechanism. Here, we found that NaBu significantly enhanced erastin-induced ferroptosis in vitro and in vivo. Compared with the group that erastin used alonely, pre-treating with NaBu exacerbated erastin-meditated GSH depletion, lipid peroxidation, and mitochondrial morphologic changes in OS cells. In a subcutaneous OS model, NaBu combined with erastin significantly reduced tumor growth and increased the levels of 4-HNE. Mechanistically, NaBu downregulated SLC7A11 transcription via regulating ATF3 expression. Overexpression of ATF3 facilitated erastin to induce ferroptosis, while ATF3 knockdown attenuated NaBu-induced ferroptosis sensitivity. In conclusion, our findings revealed a previously unidentified role of NaBu in erastin-induced ferroptosis by regulating SLC7A11, suggesting that NaBu may be a potential therapeutic agent for OS treatment.

Children's Oncology Group's 2023 blueprint for research: Renal tumors

Every year, approximately 600 infants, children, and adolescents are diagnosed with renal cancer in the United States. In addition to Wilms tumor (WT), which accounts for about 80% of all pediatric renal cancers, clear cell sarcoma of the kidney, renal cell carcinoma, malignant rhabdoid tumor, as well as more rare cancers (other sarcomas, rare carcinomas, lymphoma) and benign tumors can originate within the kidney. WT itself can be divided into favorable histology (FHWT), with a 5-year overall survival (OS) exceeding 90%, and anaplastic histology, with 4-year OS of 73.7%. Outcomes of the other pediatric renal cancers include clear cell sarcoma (5-year OS: 90%), malignant rhabdoid tumor (5-year OS: 10% for stages 3 and 4), and renal cell carcinoma (4-year OS: 84.8%). Recent clinical trials have identified novel biological prognostic markers for FHWT, and a series of Children's Oncology Group (COG) trials have demonstrated improving outcomes with therapy modification, and opportunities for further care refinement.

Deciphering the Signaling Mechanisms of Osteosarcoma Tumorigenesis

Osteosarcoma (OS) is the predominant primary bone tumor in the pediatric and adolescent populations. It has high metastatic potential, with the lungs being the most common site of metastasis. In contrast to many other sarcomas, OS lacks conserved translocations or genetic mutations; instead, it has heterogeneous abnormalities, including somatic DNA copy number alteration, ploidy, chromosomal amplification, and chromosomal loss and gain. Unfortunately, clinical outcomes have not significantly improved in over 30 years. Currently, no effective molecularly targeted therapies are available for this disease. Several genomic studies showed inactivation in the tumor suppressor genes, including p53, RB, and ATRX, and hyperactivation of the tumor promoter genes, including MYC and MDM2, in OS. Alterations in the major signaling pathways, including the PI3K/AKT/mTOR, JAK/STAT, Wnt/β-catenin, NOTCH, Hedgehog/Gli, TGF-β, RTKs, RANK/RANKL, and NF-κB signaling pathways, have been identified in OS development and metastasis. Although OS treatment is currently based on surgical excision and systematic multiagent therapies, several potential targeted therapies are in development. This review focuses on the major signaling pathways of OS, and we propose a biological rationale to consider novel and targeted therapies in the future.

New treatments for desmoid tumors

PURPOSE OF REVIEW

Desmoid tumor is a rare disease of intermediate malignancy characterized by a locally aggressive monoclonal, fibroblastic proliferation and accompanied by a variable and often unpredictable clinical course. The purpose of this review is to give an overview on the emerging new systemic treatment options for this intriguing disease for which no established or approved drugs are available yet.

RECENT FINDINGS

Over decades, surgical resection has been the established initial treatment approach; however, more recently, a paradigm shift has been introduced towards a more conservative treatment strategy. Almost 10 years ago, The Desmoid Tumor Working Group has initiated a consensus process initially in Europe and then globally with the intention to harmonize the therapeutic strategy amongst clinicians and set up management recommendations for desmoid tumor patients.

SUMMARY

This review will summarize and focus on the latest emerging impressive data on the use of gamma secretase inhibitors in this disease paving a possible future perspective in the treatment armamentarium for desmoid tumor patients.

Advances in the clinical management of high-risk Wilms tumors

Outcomes are excellent for the majority of patients with Wilms tumors (WT). However, there remain WT subgroups for which the survival rate is approximately 50% or lower. Acknowledging that the composition of this high-risk group has changed over time reflecting improvements in therapy, we introduce the authors' view of the historical and current approach to the classification and treatment of high-risk WT. For this review, we consider high-risk WT to include patients with newly diagnosed metastatic blastemal-type or diffuse anaplastic histology, those who relapse after having been initially treated with three or more different chemotherapeutics, or those who relapse more than once. In certain low- or low middle-income settings, socio-economic factors expand the definition of what constitutes a high-risk WT. As conventional therapies are inadequate to cure the majority of high-risk WT patients, advancement of laboratory and early-phase clinical investigations to identify active agents is urgently needed.

Advances in the clinical management of high-risk Wilms tumors

Outcomes are excellent for the majority of patients with Wilms tumors (WT). However, there remain WT subgroups for which the survival rate is approximately 50% or lower. Acknowledging that the composition of this high-risk group has changed over time reflecting improvements in therapy, we introduce the authors' view of the historical and current approach to the classification and treatment of high-risk WT. For this review, we consider high-risk WT to include patients with newly diagnosed metastatic blastemal-type or diffuse anaplastic histology, those who relapse after having been initially treated with three or more different chemotherapeutics, or those who relapse more than once. In certain low- or low middle-income settings, socio-economic factors expand the definition of what constitutes a high-risk WT. As conventional therapies are inadequate to cure the majority of high-risk WT patients, advancement of laboratory and early-phase clinical investigations to identify active agents is urgently needed.

Human Metastatic Cholangiocarcinoma Patient-Derived Xenografts and Tumoroids for Preclinical Drug Evaluation

PURPOSE

Cholangiocarcinoma (CCA) is usually diagnosed at advanced stages, with limited therapeutic options. Preclinical models focused on unresectable metastatic CCA are necessary to develop rational treatments. Pathogenic mutations in IDH1/2, ARID1A/B, BAP1, and BRCA1/2 have been identified in 30%-50% of patients with CCA. Several types of tumor cells harboring these mutations exhibit homologous recombination deficiency (HRD) phenotype with enhanced sensitivity to PARP inhibitors (PARPi). However, PARPi treatment has not yet been tested for effectiveness in patient-derived models of advanced CCA.

EXPERIMENTAL DESIGN

We have established a collection of patient-derived xenografts from patients with unresectable metastatic CCA (CCA_PDX). The CCA_PDXs were characterized at both histopathologic and genomic levels. We optimized a protocol to generate CCA tumoroids from CCA_PDXs. We tested the effects of PARPis in both CCA tumoroids and CCA_PDXs. Finally, we used the RAD51 assay to evaluate the HRD status of CCA tissues.

RESULTS

This collection of CCA_PDXs recapitulates the histopathologic and molecular features of their original tumors. PARPi treatments inhibited the growth of CCA tumoroids and CCA_PDXs with pathogenic mutations of BRCA2, but not those with mutations of IDH1, ARID1A, or BAP1. In line with these findings, only CCA_PDX and CCA patient biopsy samples with mutations of BRCA2 showed RAD51 scores compatible with HRD.

CONCLUSIONS

Our results suggest that patients with advanced CCA with pathogenic mutations of BRCA2, but not those with mutations of IDH1, ARID1A, or BAP1, are likely to benefit from PARPi therapy. This collection of CCA_PDXs provides new opportunities for evaluating drug response and prioritizing clinical trials.

Molecular mechanisms of osteosarcoma metastasis and possible treatment opportunities

In osteosarcoma patients, metastasis of the primary cancer is the leading cause of death. At present, management options to prevent metastasis are limited and non-curative. In this study, we review the current state of knowledge on the molecular mechanisms of metastasis and discuss promising new therapies to combat osteosarcoma metastasis. Genomic and epigenomic changes, metabolic reprogramming, transcription factors, dysregulation of physiologic pathways, and alterations to the tumor microenvironment are some of the changes reportedly involved in the regulation of osteosarcoma metastasis. Key factors within the tumor microenvironment include infiltrating lymphocytes, macrophages, cancer-associated fibroblasts, platelets, and extracellular components such as vesicles, proteins, and other secreted molecules. We conclude by discussing potential osteosarcoma-limiting agents and their clinical studies.

Osteosarcoma

Osteosarcoma is the most common primary malignant tumour of the bone. Osteosarcoma incidence is bimodal, peaking at 18 and 60 years of age, and is slightly more common in males. The key pathophysiological mechanism involves several possible genetic drivers of disease linked to bone formation, causing malignant progression and metastasis. While there have been significant improvements in the outcome of patients with localized disease, with event-free survival outcomes exceeding 60%, in patients with metastatic disease, event-free survival outcomes remain poor at less than 30%. The suspicion of osteosarcoma based on radiographs still requires pathological evaluation of a bone biopsy specimen for definitive diagnosis and CT imaging of the chest should be performed to identify lung nodules. So far, population-based screening and surveillance strategies have not been implemented due to the rarity of osteosarcoma and the lack of reliable markers. Current screening focuses only on groups at high risk such as patients with genetic cancer predisposition syndromes. Management of osteosarcoma requires a multidisciplinary team of paediatric and medical oncologists, orthopaedic and general surgeons, pathologists, radiologists and specialist nurses. Survivors of osteosarcoma require specialized medical follow-up, as curative treatment consisting of chemotherapy and surgery has long-term adverse effects, which also affect the quality of life of patients. The development of osteosarcoma model systems and related research as well as the evaluation of new treatment approaches are ongoing to improve disease outcomes, especially for patients with metastases.

LncRNA PVT-1 promotes osteosarcoma cancer stem-like properties through direct interaction with TRIM28 and TSC2 ubiquitination

Osteosarcoma, the most common pediatric bone tumor, is an aggressive heterogeneous malignancy defined by complex chromosomal aberrations. Overall survival rates remain at ~70%, but patients with chemoresistant or metastatic disease have extremely poor outcomes of <30%. A subgroup of tumors harbor amplification of chromosome 8q24.2 and increased expression of the oncogenic long noncoding RNA (lncRNA) Plasmacytoma Variant Translocation-1 (PVT-1), which is associated with an extremely poor clinical prognosis. This study demonstrates that PVT-1 is critical for osteosarcoma tumor-initiation potential. Chromatin Hybridization by RNA Purification analysis identified Tripartite-Motif Containing Family 28 (TRIM28) as a novel PVT-1 binding partner. Mechanistically, co-immunoprecipitation studies showed the PVT-1/TRIM28 complex binds and increases SUMOylation of phosphatidylinositol 3-kinase catalytic subunit type 3 (Vps34), which leads to enhanced ubiquitination and degradation of tumor suppressor complex 2 (TSC2), thus contributing to increased self-renewal and stem cell phenotypes. Furthermore, we identified that osteosarcoma cells with increased PVT-1 have enhanced sensitivity to the SUMOylation inhibitor, TAK-981. Altogether, this study elucidated a role for PVT-1 in the enhancement of cancer stem-like behaviors, including migration and invasion, in osteosarcoma, and identified the novel PVT-1/TRIM28 axis signaling cascade as a potential therapeutic target for osteosarcoma treatment.

TBL1X: At the crossroads of transcriptional and posttranscriptional regulation

Over the past 2 decades, the adaptor protein transducin β-like 1 (TBL1X) and its homolog TBL1XR1 have been shown to be upregulated in solid tumors and hematologic malignancies, and their overexpression is associated with poor clinical outcomes. Moreover, dysregulation of the TBL1 family of proteins has been implicated as a key component of oncogenic prosurvival signaling, cancer progression, and metastasis. Herein, we discuss how TBL1X and TBL1XR1 are required for the regulation of major transcriptional programs through the silencing mediator for tetanoid and thyroid hormone receptor (SMRT)/nuclear receptor corepressor (NCOR)/ B cell lymphoma 6 (BCL6) complex, Wnt/β catenin, and NF-κB signaling. We outline the utilization of tegavivint (Iterion Therapeutics), a first-in-class small molecule targeting the N-terminus domain of TBL1, as a novel therapeutic strategy in preclinical models of cancer and clinically. Although most published work has focused on the transcriptional role of TBL1X, we recently showed that in diffuse large B-cell lymphoma (DLBCL), the most common lymphoma subtype, genetic knockdown of TBL1X and treatment with tegavivint resulted in decreased expression of critical (onco)-proteins in a posttranscriptional/β-catenin-independent manner by promoting their proteasomal degradation through a Skp1/Cul1/F-box (SCF)/TBL1X supercomplex and potentially through the regulation of protein synthesis. However, given that TBL1X controls multiple oncogenic signaling pathways in cancer, treatment with tegavivint may ultimately result in drug resistance, providing the rationale for combination strategies. Although many questions related to TBL1X function remain to be answered in lymphoma and other diseases, these data provide a growing body of evidence that TBL1X is a promising therapeutic target in oncology.

The Role of Pharmacotherapeutic Agents in Children with Desmoid Tumors

Desmoid tumors (DT) are rare fibroblastic, soft-tissue tumors that do not metastasize but can aggressively infiltrate tissues causing significant chronic discomfort and/or functional impairment. In the pediatric population, the incidence of DT is greatest during infancy and adolescence but can occur at any age. Dysregulated β-catenin, most commonly resulting from mutations in either CTNNB1 or germline APC (adenomatous polyposis coli) drives DT. Most cases are sporadic but some are associated with predisposition syndromes such as familial adenomatous polyposis (FAP). Historically, treatment has been surgery. However, the recurrence rate after surgery can be high. Various systemic cytotoxic chemotherapy regimens used in other soft-tissue sarcomas have been applied to DT with differing results. Given the chronic and rarely life-threatening nature of this disease and the potential short- and long-term toxicity of these regimens, especially in children, alternative non-cytotoxic interventions have been investigated. Molecularly targeted agents such as tyrosine kinase and gamma secretase inhibitors have shown activity against DT. Innovative local control therapies are being employed as alternatives to surgery and radiation. Periods of prolonged stability and spontaneous regression in the absence of therapy in some patients has prompted wider adoption of an upfront active surveillance approach in the appropriate setting. This review will briefly summarize the epidemiology, pathophysiology, and clinical presentation of DT in children, then focus on historical, current, and future pharmacotherapeutic management and finally, propose areas for future study.

The roles of glycolysis in osteosarcoma

Metabolic reprogramming is of great significance in the progression of various cancers and is critical for cancer progression, diagnosis, and treatment. Cellular metabolic pathways mainly include glycolysis, fat metabolism, glutamine decomposition, and oxidative phosphorylation. In cancer cells, reprogramming metabolic pathways is used to meet the massive energy requirement for tumorigenesis and development. Metabolisms are also altered in malignant osteosarcoma (OS) cells. Among reprogrammed metabolisms, alterations in aerobic glycolysis are key to the massive biosynthesis and energy demands of OS cells to sustain their growth and metastasis. Numerous studies have demonstrated that compared to normal cells, glycolysis in OS cells under aerobic conditions is substantially enhanced to promote malignant behaviors such as proliferation, invasion, metastasis, and drug resistance of OS. Glycolysis in OS is closely related to various oncogenes and tumor suppressor genes, and numerous signaling pathways have been reported to be involved in the regulation of glycolysis. In recent years, a vast number of inhibitors and natural products have been discovered to inhibit OS progression by targeting glycolysis-related proteins. These potential inhibitors and natural products may be ideal candidates for the treatment of osteosarcoma following hundreds of preclinical and clinical trials. In this article, we explore key pathways, glycolysis enzymes, non-coding RNAs, inhibitors, and natural products regulating aerobic glycolysis in OS cells to gain a deeper understanding of the relationship between glycolysis and the progression of OS and discover novel therapeutic approaches targeting glycolytic metabolism in OS.

Targeting Bone Tumor and Subcellular Endoplasmic Reticulum via Near Infrared II Fluorescent Polymer for Photodynamic-Immunotherapy to Break the Step-Reduction Delivery Dilemma

Specific localization of photosensitizers (PSs) to a certain organelle could result in targeted attack to cause greater trauma to cancer cells, eventually maximizing photodynamic therapy (PDT). However, currently, efficient and precise transportation of PSs via drug delivery to tumor cells and subcellular organelles is still challenging, due to a so-called step-reduction delivery dilemma (SRDD) which also threatens anticancer drug delivery to exert their efficacy. Herein, a cascade targeting near infrared II (NIR II) fluorescent nanoparticles (NP^ER/BO-PDT ) is designed that can target bone tumor first and then target the subcellular organelle of endoplasmic reticulum (ER). It is found that NP^ER/BO-PDT achieves the targeted accumulation of the bone tumor and then ER. NP^ER/BO-PDT generates reactive oxygen species (ROS) in the subcellular organelles of ER under near infrared light irradiation. The continuous ER stress by ROS promotes the release of more damage-associated molecular patterns, induces immunogenic cell death, stimulates the adaptive immune response, and further synergistically inhibits tumor growth, achieving the so-called photodynamic-immunotherapy. Overall, this study exemplifies a safe and efficient nano-drug delivery system for a bone and ER cascade targeting via delivery of PSs to break the SRDD and highlights potential clinical translation.

Evolving strategies for management of desmoid tumor

Desmoid tumors (DTs) are rare soft tissue mesenchymal neoplasms that may be associated with impairments, disfigurement, morbidity, and (rarely) mortality. DT disease course can be unpredictable. Most DTs are sporadic, harboring somatic mutations in the gene that encodes for β-catenin, whereas DTs occurring in patients with familial adenomatous polyposis have germline mutations in the APC gene, which encodes for a protein regulator of β-catenin. Pathology review by an expert soft tissue pathologist is critical in making a diagnosis. Magnetic resonance imaging is preferred for most anatomic locations. Surgery, once the standard of care for initial treatment of DT, is associated with a significant risk of recurrence as well as avoidable morbidity because spontaneous regressions are known to occur without treatment. Consequently, active surveillance in conjunction with pain management is now recommended for most patients. Systemic medical treatment of DT has evolved beyond the use of hormone therapy, which is no longer routinely recommended. Current options for medical management include tyrosine kinase inhibitors as well as more conventional cytotoxic chemotherapy (e.g., anthracycline-based or methotrexate-based regimens). A newer class of agents, γ-secretase inhibitors, appears promising, including in patients who fail other therapies, but confirmation in Phase 3 trials is needed. In summary, DTs present challenges to physicians in diagnosis and prognosis, as well as in determining treatment initiation, type, duration, and sequence. Accordingly, evaluation by a multidisciplinary team with expertise in DT and patient-tailored management are essential. As management strategies continue to evolve, further studies will help clarify these issues and optimize outcomes for patients.

Canine and murine models of osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor in children. Despite efforts to develop and implement new therapies, patient outcomes have not measurably improved since the 1980s. Metastasis continues to be the main source of patient mortality, with 30% of cases developing metastatic disease within 5 years of diagnosis. Research models are critical in the advancement of cancer research and include a variety of species. For example, xenograft and patient-derived xenograft (PDX) mouse models provide opportunities to study human tumor cells in vivo while transgenic models have offered significant insight into the molecular mechanisms underlying OS development. A growing recognition of naturally occurring cancers in companion species has led to new insights into how veterinary patients can contribute to studies of cancer biology and drug development. The study of canine cases, including the use of diagnostic tissue archives and clinical trials, offers a potential mechanism to further canine and human cancer research. Advancement in the field of OS research requires continued development and appropriate use of animal models. In this review, animal models of OS are described with a focus on the mouse and tumor-bearing pet dog as parallel and complementary models of human OS.

Recent and Ongoing Research into Metastatic Osteosarcoma Treatments

The survival rate for metastatic osteosarcoma has not improved for several decades, since the introduction and refinement of chemotherapy as a treatment in addition to surgery. Over two thirds of metastatic osteosarcoma patients, many of whom are children or adolescents, fail to exhibit durable responses and succumb to their disease. Concerted efforts have been made to increase survival rates through identification of candidate therapies via animal studies and early phase trials of novel treatments, but unfortunately, this work has produced negligible improvements to the survival rate for metastatic osteosarcoma patients. This review summarizes data from clinical trials of metastatic osteosarcoma therapies as well as pre-clinical studies that report efficacy of novel drugs against metastatic osteosarcoma in vivo. Considerations regarding the design of animal studies and clinical trials to improve survival outcomes for metastatic osteosarcoma patients are also discussed.

Outstanding prognostic value of novel ferroptosis-related genes in chemoresistance osteosarcoma patients

Osteosarcoma (OS) is the most common bone-derived tumor, and chemoresistance is a pivotal factor in the poor prognosis of patients with OS. Ferroptosis, as an emerging modality of regulated cell death, has demonstrated potential value in tumor chemoresistance studies. Through the gene expression omnibus database in conjunction with the FerrDb database, we identified novel ferroptosis-related differentially expressed genes (DEGs) involving chemoresistance in OS patients. Subsequently, enrichment analysis, protein-protein interaction network analysis and survival analysis were performed sequentially to recognize the hub genes and ultimately to construct a predictive model. The model constructed from the TARGET database was exhibited in a nomogram and assessed by calibration curves. The prognostic value of the model and hub genes was validated separately by an independent cohort. Twenty-two ferroptosis-related DEGs were identified, including 16 up-regulated and 6 down-regulated. Among them, expressions of CBS, COCS1, EGFR, as hub genes, were significantly associated with the prognosis of OS patients and were evidenced as independent prognostic factors. An efficient prognostic model covering hub gene expressions and clinical variables was developed and validated. Combining the results of hub genes in differential analysis, the actions of hub genes in ferroptosis, and the prognostic relevance of hub genes in patients, we revealed that CBS, SOCS1 and EGFR might play essential roles in OS and its chemoresistance with potential research and clinical value.

Developments in the Antitumor Activity, Mechanisms of Action, Structural Modifications, and Structure-Activity Relationships of Steroidal Saponins

Steroidal saponins, a class of natural products formed by the combination of spirosteranes with sugars, are widely distributed in plants and have various biological activities, such as anti-tumor, anti-inflammatory, anti-bacterial, anti-Alzheimer's, anti-oxidation, etc. Particularly, extensive researches on the antitumor property of steroidal saponins have been received. Steroidal sapogenins, the aglycones of steroidal saponins, also have attracted much attention due to a vast range of pharmacological activities similar to steroidal saponins. In the past few years, structural modifications on the aglycones and sugar chains of steroidal saponins have been carried out and some achievements have been made. In this mini-review, the antitumor activity, action mechanisms, and structural modifications along with the structure-activity relationships of steroidal saponins and their derivatives are summarized.

Molecular signaling pathways as potential therapeutic targets in osteosarcoma

Among primary bone malignancies, osteosarcoma (OS) is the most common form causing morbidity and mortality in both adults and children. The interesting point about this malignancy is that nearly 10-20% of its newly diagnosed cases have developed metastasis. This adds up to the fact that the survival rate of both metastatic and non-metastatic patients of osteosarcoma hasn't changed in the past 30 years and suggests that we need to revise our therapeutic options for OS. In recent years, diverse signaling pathways have drawn the attention of the scientific community since they can be great candidates for treating complicated diseases such as cancer. In this review, we have tried to explain the pathophysiology of osteosarcoma by the help of different signaling pathways taking part in its initiation/progression and investigate how this pathway can be targeted for providing more efficient methods.

Combination of Histone Deacetylase Inhibitor Panobinostat (LBH589) with β-Catenin Inhibitor Tegavivint (BC2059) Exerts Significant Anti-Myeloma Activity Both In Vitro and In Vivo

Over the last three decades changes in the treatment paradigm for newly diagnosed multiple myeloma (MM) have led to a significant increase in overall survival. Despite this, the majority of patients relapse after one or more lines of treatment while acquiring resistance to available therapies. Panobinostat, a pan-histone deacetylase inhibitor, was approved by the FDA in 2015 for patients with relapsed MM but how to incorporate panobinostat most effectively into everyday practice remains unclear. Dysregulation of the Wnt canonical pathway, and its key mediator β-catenin, has been shown to be important for the evolution of MM and the acquisition of drug resistance, making it a potentially attractive therapeutic target. Despite concerns regarding the safety of Wnt pathway inhibitors, we have recently shown that the β-catenin inhibitor Tegavivint is deliverable and effective in in vivo models of MM. In this study we show that the combination of low concentrations of panobinostat and Tegavivint have significant in vitro and in vivo anti-MM effects including in the context of proteasome inhibitor resistance, by targeting both aerobic glycolysis and mitochondrial respiration and the down-regulation of down-stream β-catenin targets including myc, cyclinD1, and cyclinD2. The significant anti-MM effect of this novel combination warrants further evaluation for the treatment of MM patients with relapsed and/or refractory MM.

Combination of Anlotinib and Celecoxib for the Treatment of Abdominal Desmoid Tumor: A Case Report and Literature Review

Desmoid tumor is a rare disease, which is histologically characterized by local invasion, monoclonality, and fibroblast proliferation; and clinically characterized by a variable and often unpredictable course. The treatment of desmoid tumor is mainly surgical resection, but the recurrence rate is high. In recent years, a variety of treatment methods, including endocrine therapy, surgery, radiotherapy, chemotherapy, non-steroidal anti-inflammatory drugs, targeted drugs, interferon and more, have been used and achieved certain curative effects. In addition, in view of the inertia characteristics of desmoid tumor, observation is also a first-line scheme recommended by multiple guidelines. In the past, the research progress of targeted therapy for desmoid tumor is relatively slow and the curative effect is limited. Thus, targeted therapy is usually used as a remedial treatment after the failure of other conventional treatment methods. However, in recent years, with the rapid progress in the basic research of targeted therapy, some new targeted drugs are increasingly used for the clinical treatment of desmoid tumor and have achieved good results. Herein, we described a patient with aggressive fibromatosis in the abdominal cavity. Following a combined treatment using anlotinib and celecoxib, the patient achieved a partial response with mild toxicity. Simultaneously, the patient’s pain symptoms completely disappeared. This case indicates that the combination of anlotinib and NSAIDs could be an effective treatment for desmoid tumor.

AKAP9 Upregulation Predicts Unfavorable Prognosis in Pediatric Acute Myeloid Leukemia and Promotes Stemness Properties via the Wnt/β-Catenin Pathway

Background

PRKA kinase anchor protein 9 (AKAP9) is a scaffold protein involved in various cellular processes, including cell adhesion, proliferation, differentiation, and apoptosis. Although the oncogenic role of AKAP9 in solid tumors is well elucidated, the functions and mechanisms of AKAP9 in acute myeloid leukemia (AML) are still not understood.

Methods

We used the gene expression omnibus (GEO) database (GSE2191) to determine the mRNA expression of AKAP9 in the bone marrow of pediatric AML and healthy patients. We further used the therapeutically available research to generate effective treatments (TARGET) database to elucidate the relationship between AKAP9 expression and clinical outcomes in pediatric patients with AML. In addition, cell proliferation, cell cycle, apoptosis, RT-PCR, and Western blotting assays were applied to reveal the functions of AKAP9 and the underlying mechanisms of AKAP9 silencing in THP1 and HL60 cell lines.

Results

AKAP9 is overexpressed in the bone marrow of pediatric AML patients as compared with that of healthy patients. High expression of AKAP9 was found to be a predictor of poor overall survival (OS) and event-free survival (EFS). Using univariate and multivariate survival analyses, we found that high AKAP9 expression is an independent predictor of a worse OS and EFS. Functionally, AKAP9 silencing significantly inhibited AML cell proliferation, and cell cycle progression and promoted apoptosis. Moreover, AKAP9 silencing significantly downregulated the expression of stemness markers and β-catenin.

Conclusion

AKAP9 upregulation is a predictor of unfavorable prognosis, promotes stemness, and activates the Wnt/β-catenin pathway in AML patients. AKAP9 may act as a prognostic biomarker of AML in pediatric patients and a future therapeutic target.

Aldehyde dehydrogenase 3B2 promotes the proliferation and invasion of cholangiocarcinoma by increasing Integrin Beta 1 expression

Aldehyde dehydrogenases (ALDHs) play an essential role in regulating malignant tumor progression; however, their role in cholangiocarcinoma (CCA) has not been elucidated. We analyzed the expression of ALDHs in 8 paired tumor and peritumor perihilar cholangiocarcinoma (pCCA) tissues and found that ALDH3B1 and ALDH3B2 were upregulated in tumor tissues. Further survival analysis in intrahepatic cholangiocarcinoma (iCCA, n = 27), pCCA (n = 87) and distal cholangiocarcinoma (dCCA, n = 80) cohorts have revealed that ALDH3B2 was a prognostic factor of CCA and was an independent prognostic factor of iCCA and pCCA. ALDH3B2 expression was associated with serum CEA in iCCA and dCCA, associated with tumor T stage, M stage, neural invasion and serum CA19-9 in pCCA. In two cholangiocarcinoma cell lines, overexpression of ALDH3B2 promoted cell proliferation and clone formation by promoting the G1/S phase transition. Knockdown of ALDH3B2 inhibited cell migration, invasion, and EMT in vitro, and restrained tumor metastasis in vivo. Patients with high expression of ALDH3B2 also have high expression of ITGB1 in iCCA, pCCA, and dCCA at both mRNA and protein levels. Knockdown of ALDH3B2 downregulated the expression of ITGB1 and inhibited the phosphorylation level of c-Jun, p38, and ERK. Meanwhile, knockdown of ITGB1 inhibited the promoting effect of ALDH3B2 overexpression on cell proliferation, migration, and invasion. ITGB1 is also a prognostic factor of iCCA, pCCA, and dCCA and double-positive expression of ITGB1 and ALDH3B2 exhibits better performance in predicting patient prognosis. In conclusion, ALDH3B2 promotes tumor proliferation and metastasis in CCA by regulating the expression of ITGB1 and upregulating its downstream signaling pathway. The double-positive expression of ITGB1 and ALDH3B2 serves as a better prognostic biomarker of CCA.

CCR9 initiates epithelial-mesenchymal transition by activating Wnt/β-catenin pathways to promote osteosarcoma metastasis

Background

Osteosarcoma (OS) patients with lung metastasis have poor prognoses, and effective therapeutic strategies for delaying or inhibiting the spread of lung metastasis from the primary OS site are lacking. Hence, it is critical to elucidate the underlying mechanisms of OS metastasis and to identify additional new effective treatment strategies for patients.

Methods

Differential expression and functional analyses were performed to identify key genes and relevant signaling pathways associated with OS lung metastasis. The expression of CCR9 in OS cell lines and tissues was measured by RT-qPCR, western blotting and immunohistochemistry. Cell migration and invasion were assessed by wound healing and Transwell Matrigel invasion assays, respectively. The regulatory relationship between CCR9 and the Wnt/β-catenin signaling pathway was further evaluated by rescue experiments.

Results

The expression of CCR9 was elevated in OS cell lines and patients with lung metastasis. CCR9 promoted MG63 and HOS cell migration and invasion by activating the Wnt/β-catenin signaling pathway. Furthermore, knockdown of CCR9 repressed epithelial–mesenchymal transition (EMT) by downregulating mesenchymal markers (N-cadherin and Vimentin) and EMT-associated transcription factors (twist and snail) and upregulating an epithelial marker (E-cadherin).

Conclusions

Our findings suggest that CCR9 promotes EMT by activating Wnt/β-catenin pathways to promote OS metastasis. CCR9 may be a promising therapeutic target to inhibit lung metastasis and serve as a novel prognostic marker for OS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02320-0.

EIF4A3-induced circular RNA PRKAR1B promotes osteosarcoma progression by miR-361-3p-mediated induction of FZD4 expression

Emerging evidence indicates that circRNAs are broadly expressed in osteosarcoma (OS) cells and play a crucial role in OS progression. Recently, cancer-specific circRNA circPRKAR1B has been identified by high-throughput sequencing and is recorded in publicly available databases. Nevertheless, the detailed functions and underlying mechanisms of circPRKAR1B in OS remains poorly understood. By functional experiments, we found that circPRKAR1B enhanced OS cell proliferation, migration, and promotes OS epithelial–mesenchymal transition (EMT). Mechanistic investigations suggested that circPRKAR1B promotes OS progression through sponging miR-361-3p to modulate the expression of FZD4. Subsequently, we identified that EIF4A3 promoted cirPRKAR1B formation through binding to the downstream target of circPRKAR1B on PRKAR1B mRNA. Further rescue study revealed that overexpression of the Wnt signalling could impair the onco-suppressor activities of the silencing of circPRKAR1B. Interestingly, further experiments indicated that circPRKAR1B is involved in the sensitivity of chemoresistance in OS. On the whole, our results demonstrated that circPRKAR1B exerted oncogenic roles in OS and suggested the circPRKAR1B/miR-361-3p/FZD4 axis plays an important role in OS progression and might be a potential therapeutic target.

Wilms tumour

Wilms tumour (WT) is a childhood embryonal tumour that is paradigmatic of the intersection between disrupted organogenesis and tumorigenesis. Many WT genes play a critical (non-redundant) role in early nephrogenesis. Improving patient outcomes requires advances in understanding and targeting of the multiple genes and cellular control pathways now identified as active in WT development. Decades of clinical and basic research have helped to gradually optimize clinical care. Curative therapy is achievable in 90% of affected children, even those with disseminated disease, yet survival disparities within and between countries exist and deserve commitment to change. Updated epidemiological studies have also provided novel insights into global incidence variations. Introduction of biology-driven approaches to risk stratification and new drug development has been slower in WT than in other childhood tumours. Current prognostic classification for children with WT is grounded in clinical and pathological findings and in dedicated protocols on molecular alterations. Treatment includes conventional cytotoxic chemotherapy and surgery, and radiation therapy in some cases. Advanced imaging to capture tumour composition, optimizing irradiation techniques to reduce target volumes, and evaluation of newer surgical procedures are key areas for future research.

Tirapazamine suppress osteosarcoma cells in part through SLC7A11 mediated ferroptosis

Osteosarcoma is the most common primary orthopedic malignant bone tumor in adolescents. However, the traditional neoadjuvant chemotherapy regimen has reached the bottleneck. TPZ is a hypoxic prodrug that has a powerful anti-tumor effect in the hypoxic microenvironment of tumors. And ferroptosis is a newly discovered cell death in 2012, and ferroptosis inducers have been used in anti-tumor therapy research in recent decades. Though, the role of TPZ and ferroptosis in osteosarcoma remains unclear. The aim of this study was to investigate the role of TPZ in osteosarcoma and the specific mechanism. MTT assay showed the extraordinary inhibition of TPZ on three osteosarcoma cells under hypoxia. And fluorescence of Fe2+ staining was enhanced by TPZ. Western blotting showed decreased expression of SLC7A11 and GPX4. Lipid peroxidation was confirmed by MDA assay and C11 BODIPY 581/591 staining. SLC7A11 overexpression could restored the proliferation and migration abilities inhibited by TPZ. Thus, we for the first time demonstrated that TPZ could inhibit the proliferation and migration of osteosarcoma cells, and induce ferroptosis in part through inhibiting SLC7A11.

Selective Targeting of Class I Histone Deacetylases in a Model of Human Osteosarcoma

Dysregulation of histone deacetylases (HDACs) is associated with the pathogenesis of human osteosarcoma, which may present an epigenetic vulnerability as well as a therapeutic target. Domatinostat (4SC-202) is a next-generation class I HDAC inhibitor that is currently being used in clinical research for certain cancers, but its impact on human osteosarcoma has yet to be explored. In this study, we report that 4SC-202 inhibits osteosarcoma cell growth in vitro and in vivo. By analyzing cell function in vitro, we show that the anti-tumor effect of 4SC-202 involves the combined induction of cell-cycle arrest at the G2/M phase and apoptotic program, as well as a reduction in cell invasion and migration capabilities. We also found that 4SC-202 has little capacity to promote osteogenic differentiation. Remarkably, 4SC-202 revised the global transcriptome and induced distinct signatures of gene expression in vitro. Moreover, 4SC-202 decreased tumor growth of established human tumor xenografts in immunodeficient mice in vivo. We further reveal key targets regulated by 4SC-202 that contribute to tumor cell growth and survival, and canonical signaling pathways associated with progression and metastasis of osteosarcoma. Our study suggests that 4SC-202 may be exploited as a valuable drug to promote more effective treatment of patients with osteosarcoma and provide molecular insights into the mechanism of action of class I HDAC inhibitors.

Targeting ferroptosis in osteosarcoma

Osteosarcoma (OS) is the most common primary bone tumour in children and adolescents, with high degree of malignancy and an extremely poor prognosis. Ferroptosis, a non-traditional mode of regulated cell death (RCD) characterised by iron-dependent accumulation of lipid reactive oxygen species (ROS), is closely associated with a variety of cancers. It has been demonstrated that ferroptosis can regulate OS progression and exert an essential role in the treatment of OS, which is potentially of great value. By targeting ferroptosis in OS, the present review article summarises the relevant mechanisms and therapeutic applications along with discussing current limitations and future directions, which may provide a new strategy for the treatment of OS.

Cancer Stem Cells as a Source of Drug Resistance in Bone Sarcomas

Bone sarcomas are commonly characterized by a high degree of intra-tumor heterogeneity, which in part is due to the presence of subpopulations of tumor cells presenting stem cell properties. Similar to normal stem cells, these cancer stem cells (CSCs) display a drug resistant phenotype and therefore are responsible for relapses and tumor dissemination. Drug resistance in bone sarcomas could be enhanced/modulated during tumor evolution though the acquisition of (epi)-genetic alterations and the adaptation to changing microenvironments, including drug treatments. Here we summarize findings supporting the involvement of pro-stemness signaling in the development of drug resistance in bone sarcomas. This include the activation of well-known pro-stemness pathways (Wnt/β-Cat, NOTCH or JAT/STAT pathways), changes in the metabolic and autophagic activities, the alteration of epigenetic pathways, the upregulation of specific non-coding RNAs and the crosstalk with different microenvironmental factors. This altered signaling is expected to be translated to the clinic in the form of biomarkers of response and new therapies able to overcome drug resistance.

Research models and mesenchymal/epithelial plasticity of osteosarcoma

Most osteosarcomas (OSs) develop from mesenchymal cells at the bone with abnormal growth in young patients. OS has an annual incidence of 3.4 per million people and a 60-70% 5-year surviving rate. About 20% of OS patients have metastasis at diagnosis, and only 27% of patients with metastatic OS survive longer than 5 years. Mutation of tumor suppressors RB1, TP53, REQL4 and INK4a and/or deregulation of PI3K/mTOR, TGFβ, RANKL/NF-κB and IGF pathways have been linked to OS development. However, the agents targeting these pathways have yielded disappointing clinical outcomes. Surgery and chemotherapy remain the main treatments of OS. Recurrent and metastatic OSs are commonly resistant to these therapies. Spontaneous canine models, carcinogen-induced rodent models, transgenic mouse models, human patient-derived xenograft models, and cell lines from animal and human OSs have been developed for studying the initiation, growth and progression of OS and testing candidate drugs of OS. The cell plasticity regulated by epithelial-to-mesenchymal transition transcription factors (EMT-TFs) such as TWIST1, SNAIL, SLUG, ZEB1 and ZEB2 plays an important role in maintenance of the mesenchymal status and promotion of cell invasion and metastasis of OS cells. Multiple microRNAs including miR-30/9/23b/29c/194/200, proteins including SYT-SSX1/2 fusion proteins and OVOL2, and other factors that inhibit AMF/PGI and LRP5 can suppress either the expression or activity of EMT-TFs to increase epithelial features and inhibit OS metastasis. Further understanding of the molecular mechanisms that regulate OS cell plasticity should provide potential targets and therapeutic strategies for improving OS treatment.

What's in a Name? Drug Nomenclature and Medicinal Chemistry Trends using INN Publications

The World Health Organization assigns international nonproprietary names (INN), also known as common names, to compounds upon request from drug developers. Structures of INNs are publicly available and represent a source, albeit underused, to understand trends in drug research and development. Here, we explain how a common drug name is composed and analyze chemical entities from 2000 to 2021. In the analysis, we describe some changes that intertwine chemical structure, newer therapeutic targets (e.g., kinases), including a significant increase in the use of fluorine and of heterocycles, and some other evolutionary modifications, such as the progressive increase in molecular weight. Alongside these, small signs of change can be spotted, such as the rise in spirocyclic scaffolds and small rings and the emergence of unconventional structural moieties that might forecast the future to come.

Desmoid Fibromatosis: Management in an Era of Increasing Options

PURPOSE OF REVIEW

Desmoid fibromatosis (DF) is a locally aggressive clonal neoplasm with locally aggressive behavior and no metastatic potential. Historical treatment of DF has consisted primarily of up-front surgery when feasible. In recent years, recognition that DF can spontaneously stabilize or involute has allowed for many patients to be managed with watchful waiting rather than intervention. This review is intended to review recent developments in the treatment of DF.

RECENT FINDINGS

Recent studies have demonstrated prospectively that patients with DF often have improvement in their lesions without intervention, enabling an initial period of surveillance as a standard option for patients with mild symptoms. Given the lengthening list of effective systemic treatments, including sorafenib, pazopanib, and experimental agents, there has been a less reliance on local therapies for those patients who require treatment. For patients with DF that require treatment, there is a growing list of options that includes radiation therapy (RT), percutaneous ablation, and a growing list of systemic agents with favorable toxicity profiles.

PTHR1 in osteosarcoma: Specific molecular mechanisms and comprehensive functional perspective

Osteosarcoma occurs largely in children and adolescents and is the most common primary malignant tumour of bone. Although surgical advances and neoadjuvant chemotherapy have made great strides in recent years, rates of local recurrence and lung metastasis remain high, with a plateau in overall survival during the past decade. It is thus urgent to explore the pathogenesis of osteosarcoma and identify potential therapeutic targets. Parathyroid hormone receptor 1 (PTHR1) belongs to the broad family of G protein–coupled receptors, binding both parathyroid hormone (PTH) and parathyroid hormone–related peptide (PTHrP, a paracrine factor). Previous studies have shown that in tissues and cells of osteosarcoma, expression of PTHR1 is markedly increased, correlating with aggressive biologic behaviour and a poor prognosis. PTHR1 expression also correlates closely with epigenetic regulation, transcriptional regulation, post‐translational modification and protein interaction. Herein, we have summarized the latest research on the role played by PTHR1 in progression of osteosarcoma, assessing its clinical utility as a novel biomarker and its therapeutic ramifications.

Nomograms to predict lung metastasis probability and lung metastasis subgroup survival in malignant bone tumors

The aim of this study was to construct and validate nomograms for predicting lung metastasis and lung metastasis subgroup overall survival in malignant primary osseous neoplasms. Least absolute shrinkage and selection operator, logistic and Cox analyses were used to identify risk factors for lung metastasis in malignant primary osseous neoplasms and prognostic factors for overall survival in the lung metastasis subgroup. Further, nomograms were established and validated. A total of 3184 patients were collected. Variables including age, histology type, American Joint Committee on Cancer T and N stage, other site metastasis, tumor extension and surgery were extracted for the nomograms. The authors found that nomograms could provide an effective approach for clinicians to identify patients with a high risk of lung metastasis in malignant primary osseous neoplasms and perform a personalized overall survival evaluation for the lung metastasis subgroup.

Recent Insights into Therapy Resistance in Osteosarcoma

Osteosarcoma, the most common bone malignancy of childhood, has been a challenge to treat and cure. Standard chemotherapy regimens work well for many patients, but there remain minimal options for patients with progressive or resistant disease, as clinical trials over recent decades have failed to significantly improve survival. A better understanding of therapy resistance is necessary to improve current treatments and design new strategies for future treatment options. In this review, we discuss known mechanisms and recent scientific advancements regarding osteosarcoma and its patterns of resistance against chemotherapy, radiation, and other newly-introduced therapeutics.

Wnt Signaling in Osteosarcoma

Wnt molecules are a class of cysteine-rich secreted glycoproteins that participate in various developmental events during embryogenesis and adult tissue homeostasis. Since its discovery in 1982, the roles of Wnt signaling have been established in various key regulatory systems in biology. Wnt signals exert pleiotropic effects, including mitogenic stimulation, cell fate specification, and differentiation. The Wnt signaling pathway in humans has been shown to be involved in a wide variety of disorders including colon cancer, sarcoma, coronary artery disease, tetra-amelia, Mullerian duct regression, eye vascular defects, and abnormal bone mass. The canonical Wnt pathway functions by regulating the function of the transcriptional coactivator β-catenin, whereas noncanonical pathways function independent of β-catenin. Although the role of Wnt signaling is well established in epithelial malignancies, its role in mesenchymal tumors is more controversial. Some studies have suggested that Wnt signaling plays a pro-oncogenic role in various sarcomas by driving cell proliferation and motility; however, others have reported that Wnt signaling acts as a tumor suppressor by committing tumor cells to differentiate into a mature lineage. Wnt signaling pathway also plays an important role in regulating cancer stem cell function. In this review, we will discuss Wnt signaling pathway and its role in osteosarcoma.

The Wnt Signalling Pathway: A Tailored Target in Cancer

Cancer is one of the greatest public health challenges. According to the World Health Organization (WHO), 9.6 million cancer deaths have been reported in 2018. The most common cancers include lung, breast, colorectal, prostate, skin (non-melanoma) and stomach cancer. The unbalance of physiological signalling pathways due to the acquisition of mutations in tumour cells is considered the most common cancer driver. The Wingless-related integration site (Wnt)/β-catenin pathway is crucial for tissue development and homeostasis in all animal species and its dysregulation is one of the most relevant events linked to cancer development and dissemination. The canonical and the non-canonical Wnt/β-catenin pathways are known to control both physiological and pathological processes, including cancer. Herein, the impact of the Wnt/β-catenin cascade in driving cancers from different origin has been examined. Finally, based on the impact of Extracellular Vesicles (EVs) on tumour growth, invasion and chemoresistance, and their role as tumour diagnostic and prognostic tools, an overview of the current knowledge linking EVs to the Wnt/β-catenin pathway is also discussed.

The potential roles of exosomal noncoding RNAs in osteosarcoma

Clinically, it is difficult to efficaciously screen and diagnose osteosarcoma (OS) in advance due to the low sensitivity and poor specificity of the existing tumor markers. Exosomes (Exos) are nanoscale vesicles containing RNAs, lipids, and proteins with a diameter of 30-100 nm. They are multivesicular bodies formed during the invagination of lysosomal particles in cells and released extracellularly after fusing with cell membranes. Besides, Exos are important carriers of cell-to-cell communication signals and genetic materials in the tumor microenvironment. During tumorigenesis, the tumor cells interplay with immune cells, endothelial cells, and related fibroblasts through Exos and boost cancer development. After altering the surrounding microenvironment, the Exos drive tumor cells to proliferate, speed up angiogenesis, and boost cancers to develop along with body fluid transportation. Currently, Exos are becoming novel noninvasive tumor diagnostic markers with high sensitivity, exerting pivotal impacts in fundamental research and clinical applications. Here, we review the existing literature on the roles of exosomal noncoding RNAs in OS progression and their potential clinical applications as novel biomarkers and therapeutics.

Desmoid tumors: To treat or not to treat, That is the question

Desmoid tumors (DTs) are a rare disease of intermediate malignancy characterized histologically by a locally aggressive, monoclonal, fibroblastic proliferation and clinically by a variable and often unpredictable course. For decades, surgical resection has been the standard initial treatment approach; however, more recently, a paradigm shift toward a more conservative treatment strategy has been introduced. More than 5 years ago, The Desmoid Tumor Working Group started a consensus initiative in Europe with the aim of harmonizing the strategy among clinicians and setting up treatment recommendations for patients with DTs. This review summarizes the latest joint, global, evidence-based guideline approach to DT management. Moreover, a number of gray areas in the treatment recommendations are discussed, and possible future perspectives on the treatment armamentarium for patients with DTs are presented.

HSPA1L Enhances Cancer Stem Cell-Like Properties by Activating IGF1Rβ and Regulating β-Catenin Transcription

Studies have shown that cancer stem cells (CSCs) are involved in resistance and metastasis of cancer; thus, therapies targeting CSCs have been proposed. Here, we report that heat shock 70-kDa protein 1-like (HSPA1L) is partly involved in enhancing epithelial–mesenchymal transition (EMT) and CSC-like properties in non-small cell lung cancer (NSCLC) cells. Aldehyde dehydrogenase 1 (ALDH1) is considered a CSC marker in some lung cancers. Here, we analyzed transcriptional changes in genes between ALDH1high and ALDH1low cells sorted from A549 NSCLC cells and found that HSPA1L was highly expressed in ALDH1high cells. HSPA1L played two important roles in enhancing CSC-like properties. First, HSPA1L interacts directly with IGF1Rβ and integrin αV to form a triple complex that is involved in IGF1Rβ activation. HSPA1L/integrin αV complex-associated IGF1Rβ activation intensified the EMT-associated cancer stemness and γ-radiation resistance through its downstream AKT/NF-κB or AKT/GSK3β/β-catenin activation pathway. Secondly, HSPA1L was also present in the nucleus and could bind directly to the promoter region of β-catenin to function as a transcription activator of β-catenin, an important signaling protein characterizing CSCs by regulating ALDH1 expression. HSPA1L may be a novel potential target for cancer treatment because it both enhances IGF1Rβ activation and regulates γβ-catenin transcription, accumulating CSC-like properties.

Lycorine inhibits tumor growth of human osteosarcoma cells by blocking Wnt/β-catenin, ERK1/2/MAPK and PI3K/AKT signaling pathway

Osteosarcoma (OS) is the most common type of primary bone cancer. Even with advances in early diagnosis and aggressive treatment, the overall prognosis for OS remains to be further elevated. Lycorine was an isoquinoline alkaloid mainly existed in the bulb of lyco salvia miltiorrhiza and was shown to inhibit several types of cancer. In the present study, we investigated the anti-OS activity of lycorine and the possible underlying mechanism. We found that lycorine inhibited cell proliferation of human OS cells while had lower cytotoxcity against normal cells, and triggered cell cycle arrest at the G1/S transition. Moreover, we validated that lycorine promoted apoptosis via death receptor pathway and mitochondrial pathway, suppressed migration and invasion by reversing epithelial mesenchymal transition (EMT) and suppressing the degradation of extracellular matrix (ECM) in vitro. In addition, orthotopic implantation model of 143B OS cells further confirmed that lycorine suppressed OS growth and lung metastasis in vivo. Mechanically, lycorine reduced the protein level of β-catenin and its' downstream molecule c-Myc. Furthermore, lycorine also decreased the phosphorylation of ERK1/2 and AKT. Together, our results reveal that lycorine may inhibit tumor growth of OS cells possibly through suppressing Wnt/β-catenin, ERK1/2 and PI3K/AKT signaling pathway.