IDH1 and IDH2 mutations are frequent events in central chondrosarcoma and central and periosteal chondromas but not in other mesenchymal tumours

Cartilage Forming Tumors of the Skeleton

Cartilage-forming tumors are a broad and diverse group of neoplasms frequently affecting the skeleton. Distinguishing between the members of this group is important because of significant differences in treatment and prognosis. Accurate diagnosis can be challenging because of similarities in their clinical, radiographic, and pathologic features. Immunohistochemistry and molecular tools are helpful in select instances. Therefore, careful evaluation and correlation of these features are essential in arriving at the correct diagnosis and appropriate patient management. This review provides an overview of the current literature, emphasizing helpful features in diagnosis.

Advancing Systemic Therapy in Chondrosarcoma: New Horizons

The systemic treatment landscape for advanced and metastatic chondrosarcoma, a malignancy with limited responsiveness to conventional therapies, has always been notoriously challenging. While standard chemotherapy offers minimal benefits, certain subtypes, such as mesenchymal and dedifferentiated chondrosarcomas, have shown some response to systemic therapies initially developed for other sarcomas. Investigational strategies are focusing on molecular targets, including mutations in the isocitrate dehydrogenase gene (IDH), signaling pathways, such as hedgehog and death receptor 5 (DR5) and immune modulation. IDH mutations, notably found in conventional and dedifferentiated chondrosarcomas, have prompted the evaluation of IDH inhibitors, which have demonstrated promising efficacy in preclinical and early clinical trials, despite limited data in chondrosarcoma. Additionally, the hedgehog pathway, implicated in chondrosarcoma progression, has been targeted with inhibitors, although clinical translation has shown mixed results. Immunotherapy, including programmed cell death 1 (PD-1) checkpoint inhibitors and chimeric antigen receptor-T (CAR-T) cells, is also being investigated but faces challenges due to the immunosuppressive tumour microenvironment. Among new approaches, DR5 agonists such as INBRX-109 have shown single-agent efficacy, with minimal toxicity, opening possibilities for use in combination therapies to improve outcomes. Given the heterogenous and treatment-resistant nature of chondrosarcoma, we highlight the need for multi-omics and genetic profiling to guide personalized, combination therapies that target multiple carcinogenic pathways. The integration of multi-targeted approaches could enhance efficacy, address tumour heterogeneity, and overcome resistance, presenting a hopeful direction for systemic therapy in this challenging cancer. The investigation of combination regimens with IDH inhibitors, immunotherapy and DR5 agonists hold promise for transforming the management of advanced chondrosarcoma.

Application of patient derived xenograft model in personalized drug screening for chondrosarcoma of head and neck: A preclinical study

OBJECTIVES

The effect of radiotherapy and chemotherapy on head and neck chondrosarcoma (HNCS) has not been unanimously determined because of the rarity of HNCS. Patient-Derived Xenograft (PDX) model is considered to be a good preclinical model for new drug development and personalized drug screening. We performed this study to investigate the preclinical application and value of PDX model in drug screening for HNCS.

MATERIALS AND METHODS

Tumor tissues of a patient with HNCS who underwent surgical treatment in the Department of Head and Neck Oncology of our hospital were collected. The PDX model was established in NCG mice and successfully passed to the P3 generation in nude mice. After the tumor grew to a certain size, three drugs targeting different molecules (Nilotinib, Regorafenib, Rapamycin) were given respectively. The treatment efficiency and safety were observed.

RESULTS

NCG mouse is a kind of mouse that can successfully establish the PDX model of HNCS, and the PDX model can be stably passed in nude mice. The PDX tumor show similar histopathological characteristics to the parent tumors. After stable passaging, the mesenchymal cells were reduced and the tumor cells were increased in PDX tumor, making it easier to extract primary tumor cells. In the P3 PDX tumor, oral administration of nilotinib and regorafenib or intraperitoneal injection of rapamycin could significantly reduce the tumor size.

CONCLUSION

For rare tumors such as HNCS, PDX model is a good preclinical model for personalized drug screening and has good clinical application value.

Chondrosarcoma: New Molecular Insights, Challenges in Near-Patient Preclinical Modeling, and Therapeutic Approaches

Chondrosarcoma (CS), the second most common malignant bone tumor after osteosarcoma, accounts for 20-30% of all malignant bone tumors. It mainly affects adults, middle-aged, and elderly people. The CS family includes various entities displaying peculiar biological, genetic, and epigenetic characteristics and clinical behaviors. Conventional CS is the most common subtype. High-grade, dedifferentiated, and mesenchymal CS, as well as unresectable and metastatic CS, exhibit poor prognoses due to their intrinsic resistance to radiotherapy and chemotherapy, underscoring the urgent need for novel therapeutic strategies. CS research is dealing with several challenges. Experimental studies can rely on animal and patient-derived models, but the paucity of representative near-patient preclinical models has hampered predictive drug screening research. This review describes the main clinical and molecular features of CS subtypes, discussing recent data on the genetic alterations and molecular mechanisms involved in CS pathogenesis and progression. The review provides an overview of the current in vitro and in vivo CS models, discusses their advantages and limitations, and highlights the recent efforts in the development of new targeted therapies against CS dependencies, including IDH1/2 mutations, NAD+ dependency, and SIRT1-HIF-2α axis, or exploring DR5 targeting, antiangiogenic therapies, epigenetic drugs, and immunological approaches. All such strategies, in combination with advanced preclinical modeling and personalized multi-omic profiling, hold promise for improving the survival of patients with advanced CS.

Updates in non-neoplastic orthopaedic pathology: what you don't know can hurt you!

Even though the average surgical pathologist reviews far more non-neoplastic orthopaedic pathology on a daily basis, most current research focuses on rare tumours and their even less frequent molecular events. Our experiences among consults and focused conferences strongly suggest that there remains a practice gap regarding knowledge and diagnosing specific non-neoplastic orthopaedic conditions. One of the most frequent intraoperative consultations performed in the USA, among both academic and private institutions, relates to revision arthroplasty and the determination of infection in periprosthetic joints. Pathologists play a critical role in this algorithm, helping determine intraoperatively whether patients require antibiotic spacers prior to reimplantation. Many pathology departments have abandoned the examination of arthroplasty specimens because they (and their surgeons) mistakenly believe there is little clinically relevant information to be gained by thorough pathological examination. However, recent literature has challenged this concept, emphasising the importance of distinguishing avascular necrosis (from osteoarthritis/degenerative joint disease with secondary osteonecrosis), subchondral insufficiency fracture, septic arthritis (from so-called 'sterile' osteomyelitis/pseudoabscesses), underlying crystalline diseases and incidental/occult neoplasia. Histological evaluation of historically insignificant orthopaedic specimens, such as tenosynovium from carpal tunnel syndrome/trigger finger, is now seen as valuable in early diagnosis of cardiac amyloidosis. Not infrequently, orthopaedic conditions like haemosiderotic synovitis, osteocartilaginous loose bodies or rheumatoid nodules, may histologically mimic bona fide neoplasms, notably diffuse tenosynovial giant cell tumour, synovial chondromatosis and epithelioid sarcoma, respectively. Here is a review of the more common non-neoplastic orthopaedic conditions, those likely to be examined by the practising surgical pathologist, with updates and guidelines for establishing clinically relevant diagnoses.

(B)On(e)-cohistones and the epigenetic alterations at the root of bone cancer

Identification of mutations in histones in a number of human neoplasms and developmental syndromes represents the most compelling evidence to date for a causal role of epigenetic perturbations in human disease. In most cases, these mutations have gain of function properties that cause deviation from normal developmental processes leading to embryo defects and/or neoplastic transformation. These exciting discoveries represent a step-change in our understanding of the role of chromatin (dys)regulation in development and disease. However, the mechanisms of action of oncogenic histone mutations (oncohistones) remain only partially understood. Here, we critically assess existing literature on oncohistones focussing mainly on bone neoplasms. We show how it is possible to draw parallels with some of the cell-autonomous mechanisms of action described in paediatric brain cancer, although the functions of oncohistones in bone tumours remain under-investigated. In this respect, it is becoming clear that histone mutations targeting the same residues display, at least in part, tissue-specific oncogenic mechanisms. Furthermore, it is emerging that cancer cells carrying oncohistones can modify the surrounding microenvironment to support growth and/or alter differentiation trajectories. A better understanding of oncohistone function in different neoplasms provide potential for identification of signalling that could be targeted therapeutically. Finally, we discuss some of the main concepts and future directions in this research area, while also drawing possible connections and parallels with other cancer epigenetic mechanisms.

IDH1/2 Mutations in Cancer: Unifying Insights and Unlocking Therapeutic Potential for Chondrosarcoma

Chondrosarcomas, a rare form of bone sarcomas with multiple subtypes, pose a pressing clinical challenge for patients with advanced or metastatic disease. The lack of US Food and Drug Administration (FDA)-approved medications underscores the urgent need for further research and development in this area. Patients and their families face challenges as there are no systemic therapeutic options available with substantial effectiveness. A significant number (50-80%) of chondrosarcomas have a mutation in the isocitrate dehydrogenase (IDH) genes. This review focuses on IDH-mediated pathogenesis and recent pharmacological advances with novel IDH inhibitors, explores their potential therapeutic value, and proposes potential future avenues for clinical trials combining IDH inhibitors with other systemic agents for chondrosarcomas.

Liquid Biopsy for Spinal Tumors: On the Frontiers of Clinical Application

STUDY DESIGN

Narrative review.

OBJECTIVES

This article aims to provide a narrative review of the current state of research for liquid biopsy in spinal tumors and to discuss the potential application of liquid biopsy in the clinical management of patients with spinal tumors.

METHODS

A comprehensive review of the literature was performed using PubMed, Google Scholar, Medline, Embase and Cochrane databases, and the review was limited to articles of English language. All the relevant articles which were identified to be related to liquid biomarker study in spinal tumors, were studied in full text.

RESULTS

Liquid biopsy has revolutionized the field of precision medicine by guiding personalized clinical management of cancer patients based on the liquid biomarker status. In recent years, more research has been done to investigate its potential utilization in patients with tumors from the spine. Herein, we review the liquid biomarkers that have been proposed in different spine malignancies including chordoma, chondrosarcoma, Ewing sarcoma, osteosarcoma, astrocytoma and ependymoma. We also discuss the wide window of opportunity to utilize these liquid biomarkers in diagnosis, treatment response, monitoring, and detection of minimal residual disease in patients with spinal tumors.

CONCLUSIONS

Liquid biomarkers, especially blood-derived circulating tumor DNA, has a promising clinical utility as they are disease-specific, minimally invasive, and the procedure is repeatable. Prospective studies with larger populations are needed to fully establish its use in the setting of spinal tumors.

Japanese orthopaedic association (JOA) clinical practice guideline on the management of primary malignant bone tumors - Secondary publication

BACKGROUND

In Japan, there are currently no general guidelines for the treatment of primary malignant bone tumors. Therefore, the Japanese Orthopaedic Association established a committee to develop guidelines for the appropriate diagnosis and treatment of primary malignant bone tumors for medical professionals in clinical practice.

METHODS

The guidelines were developed in accordance with "Minds Clinical Practice Guideline Development Handbook 2014″ and "Minds Clinical Practice Guideline Development Manual 2017". The Japanese Orthopaedic Association's Bone and Soft Tissue Tumor Committee established guideline development and systematic review committees, drawing members from orthopedic specialists leading the diagnosis and treatment of bone and soft tissue tumors. Pediatricians, radiologists, and diagnostic pathologists were added to both committees because of the importance of multidisciplinary treatment. Based on the diagnosis and treatment algorithm for primary malignant bone tumors, important decision-making points were selected, and clinical questions (CQ) were determined. The strength of recommendation was rated on two levels and the strength of evidence was rated on four levels. The recommendations published were selected based on agreement by 70% or more of the voters.

RESULTS

The guideline development committee examined the important clinical issues in the clinical algorithm and selected 22 CQs. The systematic review committee reviewed the evidence concerning each CQ and a clinical value judgment was added by experts. Eventually, 25 questions were published and the text of each recommendation was determined.

CONCLUSION

Since primary malignant bone tumors are rare, there is a dearth of strong evidence based on randomized controlled trials, and recommendations cannot be applied to all the patients. In clinical practice, appropriate treatment of patients with primary malignant bone tumors should be based on the histopathological diagnosis and degree of progression of each case, using these guidelines as a reference.

Chitosan Nanoparticle-Mediated Delivery of Alstonia venenata R.Br. Root Methanolic Extract: A Promising Strategy for Breast Cancer Therapy in DMBA-Induced Breast Cancer in Sprague Dawley Rats

Alstonia venenata R.Br., a plant native to the Western Ghats, is recognized for its diverse medicinal properties. The plant's extracts, particularly rich in alkaloids and other bioactive compounds, have shown potential anticancer activity. This study investigates the therapeutic potential of chitosan nanoparticles (CNPs) loaded with the root methanolic extract (RME) of A. venenata in combating breast cancer induced by dimethylbenz(a)anthracene (DMBA) in female Sprague Dawley rats. The RME-loaded chitosan nanoparticles (RME-EnCNPs) were synthesized and characterized, and their in vivo efficacy was evaluated. Treatment with RME-EnCNPs significantly inhibited tumor progression, which is evidenced by reduced tumor volume, burden, and incidence. Moreover, the nanoparticles demonstrated a sustained release of the active compounds, leading to marked improvements in various biochemical, enzymatic, and histopathological parameters. The study found that both RME and RME-EnCNPs effectively suppressed tumor growth, with RME-EnCNPs showing superior efficacy in modulating tumor progression. Antioxidant assays revealed that treatment with RME-EnCNPs (500 mg/kg) resulted in significant increases in total protein, superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione (GSH) levels, alongside a marked reduction in lipid peroxidation (LPO) (p < 0.001). These findings suggest that RME-EnCNPs exert a potent antioxidant effect, mitigating oxidative stress within the tumor microenvironment. The root extract of A. venenata and its nanoparticle formulation hold promise as a potential therapeutic agent for breast cancer, warranting further investigation to isolate active bioactive compounds and elucidate their mechanisms of action.

Prevalence of SPOP and IDH Gene Mutations in Prostate Cancer in a Jordanian Population

Speckle-type POZ (SPOP) is described as an essential tumor suppressor factor in gastric cancer, colorectal cancer, and prostate cancer (PCa). SPOP gene mutations were reported in primary human PCa. Isocitrate dehydrogenase-1 (IDH1) oncogene mutations were detected in gliomas, acute myeloid leukemia, some benign and malignant cartilaginous tumors, and only 1% of PCa. This study aimed to investigate the prevalence of mutations of SPOP and IDH1 genes in PCa in the Jordanian population. One hundred formalin-fixed paraffin-embedded tissue samples were collected from patients diagnosed with prostate adenocarcinoma. The obtained specimens were subjected to genomic DNA extraction, PCR amplification, and direct sequencing of exons 4, 5, 6, and 7 of the SPOP gene and exon 6 of the IDH1 gene. SPOP gene mutations were found in 17% of PCa cases, while no mutation was detected in the screened exon 6 of the IDH1 gene. Clinicopathological data demonstrated a strong correlation between prostate-specific antigen (PSA) levels and both Gleason score (GS) and the International Society of Urological Pathology (ISUP) grade group (GG). There was no significant correlation between PSA levels and age (p = 0.816) nor there were significant associations for SPOP mutational status with age (p = 0.659), PSA levels (p = 0.395), GS (p = 0.259), and ISUP GG (p = 0.424) in the tested population. The study found a strong correlation between PSA levels and both GS and ISUP GG. It also identified a high frequency (17%) of SPOP gene mutations in Jordanian Arab PCa patients, mainly in exon 7. No IDH1 mutations were detected in exon 6.

Delineating the nexus between gut-intratumoral microbiome and osteo-immune system in bone metastases

Emerging insights in osteoimmunology have enabled researchers to explore in depth the role of immune modulation in regulating bone health. Bone is one of the common sites of metastasis notably in case of breast cancer, prostate cancer and several other cancer types. High calcium ion concentration and presence of several factors within the mineralized bone matrix including TGF-β, BMP etc., aid in tumor growth and proliferation. Accumulating evidence has substantiated the role of the gut-microbiota (GM) in tumorigenesis, further providing a strong impetus for the growing "immune-cancer-gut microbiota" relationship. Recent advancements in research further highlight the importance of the intra-tumor microbiota in conjunction with GM in cancer metastasis. Intratumoral microbiota owing to their ability to cause genetic instability, mutations, and epigenetic modifications within the tumor microenvironment, has been recognized to affect cancer cell physiology. The host microbiota and immune system crosstalk shapes the innate and adaptive arms of the immune system, which is the key player in cancer progression. In this review, we aim to decipher the role of microorganisms mediating bone metastasis by shedding light on the immuno-onco-microbiome (IOM) axis. We discussed the feasible cancer therapeutic interventions based on the modulation of the microbiome-immune cell axis which includes prebiotics, probiotics, and postbiotics. Here, we leverage the conceptual framework based on the published articles on microbiota-based therapies to target bone metastases. Understanding this complicated nexus will provide insights into fundamental factors governing bone metastases which will subsequently help in managing this malignancy with better efficacy.

Genetics and Molecular Pathogenesis of the Chondrosarcoma: A Review of the Literature

The chondrosarcoma, a cartilage-forming bone tumor, presents significant clinical challenges due to its resistance to chemotherapy and radiotherapy. Surgical excision remains the primary treatment, but high-grade chondrosarcomas are prone to recurrence and metastasis, necessitating the identification of reliable biomarkers for diagnosis and prognosis. This review explores the genetic alterations and molecular pathways involved in chondrosarcoma pathogenesis. These markers show promise in distinguishing between benign enchondromas and malignant chondrosarcomas, assessing tumor aggressiveness, and guiding treatment. While these advancements offer hope for more personalized and targeted therapeutic strategies, further clinical validation of these biomarkers is essential to improve prognostic accuracy and patient outcomes in chondrosarcoma management.

Research trends and foci in chondrosarcoma: A bibliometric and network analysis

Chondrosarcoma is 1 of the most common malignant bone tumors, with dedicated research being conducted by scientists worldwide. The purpose of this study was to guide researchers in identifying valuable scholars, institutions, and countries, provide recommendations for journal submissions, and explore research trends and hotspots in chondrosarcoma studies through literature analysis. Data for this study were collected from the Web of Science Core Collection website. The R package bibliometrix was utilized for citation metrics analysis, VOSviewer for network analysis, and CiteSpace for generating keywords citation burst maps. The analysis focused on publications from 2000 to 2023, identifying trends, authorship patterns, and collaboration networks. A total of 2085 articles were initially identified, but after excluding non-English articles and those outside the study's time range, 2022 articles were included. The field comprised 9954 author records, with an average of 6.37 coauthors per document and 13.9% international co-authorships. Publications in chondrosarcoma research have shown an average annual growth rate of 3.9%. The most influential author identified was Tang Chih-Hsin from China Medical University. Significant contributions came from China Medical University and Leiden University, with China showing a dramatic increase in publications while the United States maintained a leading position in the field. The study highlights an increasing trend in chondrosarcoma research publications and identifies key contributors and institutions. Cancer emerged as 1 of the most influential journals in the field. Future research is likely to focus on targeted therapy for refractory chondrosarcomas, indicating a potential new hotspot in the ongoing efforts to understand and treat this malignancy.

Deciphering the multifaceted roles and clinical implications of 2-hydroxyglutarate in cancer

Increasing evidence indicates that 2-hydroxyglutarate (2HG) is an oncometabolite that drives tumour formation and progression. Due to mutations in isocitrate dehydrogenase (IDH) and the dysregulation of other enzymes, 2HG accumulates significantly in tumour cells. Due to its structural similarity to α-ketoglutarate (αKG), accumulated 2HG leads to the competitive inhibition of αKG-dependent dioxygenases (αKGDs), such as KDMs, TETs, and EGLNs. This inhibition results in epigenetic alterations in both tumour cells and the tumour microenvironment. This review comprehensively discusses the metabolic pathways of 2HG and the subsequent pathways influenced by elevated 2HG levels. We will delve into the molecular mechanisms by which 2HG exerts its oncogenic effects, particularly focusing on epigenetic modifications. This review will also explore the various methods available for the detection of 2HG, emphasising both current techniques and emerging technologies. Furthermore, 2HG shows promise as a biomarker for clinical diagnosis and treatment. By integrating these perspectives, this review aims to provide a comprehensive overview of the current understanding of 2HG in cancer biology, highlight the importance of ongoing research, and discuss future directions for translating these findings into clinical applications.

Single cell analysis of Idh mutant growth plates identifies cell populations responsible for longitudinal bone growth and enchondroma formation

Enchondromas are a common tumor in bone that can occur as multiple lesions in enchondromatosis, which is associated with deformity of the affected bone. These lesions harbor somatic mutations in IDH and driving expression of a mutant Idh1 in Col2 expressing cells in mice causes an enchondromatosis phenotype. Here we compared growth plates from E18.5 mice expressing a mutant Idh1 with control littermates using single cell RNA sequencing. Data from Col2 expressing cells were analysed using UMAP and RNA pseudo-time analyses. A unique cluster of cells was identified in the mutant growth plates that expressed genes known to be upregulated in enchondromas. There was also a cluster of cells that was underrepresented in the mutant growth plates that expressed genes known to be important in longitudinal bone growth. Immunofluorescence showed that the genes from the unique cluster identified in the mutant growth plates were expressed in multiple growth plate anatomic zones, and pseudo-time analysis also suggested these cells could arise from multiple growth plate chondrocyte subpopulations. This data supports the notion that a subpopulation of chondrocytes become enchondromas at the expense of contributing to longitudinal growth.

IDH Mutations in Glioma: Molecular, Cellular, Diagnostic, and Clinical Implications

In 2021, the World Health Organization classified isocitrate dehydrogenase (IDH) mutant gliomas as a distinct subgroup of tumors with genetic changes sufficient to enable a complete diagnosis. Patients with an IDH mutant glioma have improved survival which has been further enhanced by the advent of targeted therapies. IDH enzymes contribute to cellular metabolism, and mutations to specific catalytic residues result in the neomorphic production of D-2-hydroxyglutarate (D-2-HG). The accumulation of D-2-HG results in epigenetic alterations, oncogenesis and impacts the tumor microenvironment via immunological modulations. Here, we summarize the molecular, cellular, and clinical implications of IDH mutations in gliomas as well as current diagnostic techniques.

A Rare Entity of the Anterior Chest Cage Rib Chondrosarcoma: A Case Report and Review of Literature

Primary bone cancers, also called bone sarcomas, can arise anywhere in the body. Less than 1% of cancers are identified as primary bone cancers annually, and they are correlated with high rates of morbidity and death. Twenty to twenty-seven percent of primary malignant osseous neoplasms are chondrosarcomas, the rarest subtype of bone sarcomas. The incidence of chondrosarcomas in Saudi Arabia was less common than globally discovered chondrosarcomas, and only a few cases have been recorded. The most common presentation of the primary chondrosarcoma (CS) is to encompass the bony skeleton of the long bones of the lower extremities and the axial skeleton. Detecting primary CS in the anterior chest wall and the rib cage is rare. To our knowledge, chondrosarcomas of the ribs encroaching on the anterior chest are rare and have never been documented in Saudi Arabian or Middle East medical or surgical literature. We describe a case of a 32-year-old female with chondrosarcoma of the left anterior seventh rib, with no other medical or surgical histories. Further work-up at the tertiary care center, including computed tomography-scan, magnetic resonance imaging, and detailed triple bone scan (nuclear scan) imaging and histological biopsy, revealed features of chondrosarcoma arising from the ribs and involving the surrounding soft tissue. The patient underwent en masse surgical resection with a 4 cm margin, including the sixth rib and partial resection of the left hemidiaphragm and a small piece of the diaphragm. The patient was discharged without any inauspicious consequences. In the current work, we comprehensively discussed a scarce case of the anterior chest wall chondrosarcoma affecting the rib. This case highlights the importance of early detection of a rare tumor using a toolkit diagnostic approach to provide successful management and caring of the patient. Consequently, this will guarantee encouraging outcomes and thus stress the fruitful role of the surgery as the best curative modality in chondrosarcoma patients.

Mesenchymal Chondrosarcoma of the Mandible, a Big Dilemma: Report of a Rare Case in Mesenchymal Chondrosarcoma of the Mandible-Report of a Case With Discussion of Diagnostic and Therapeutic Dilemmas

Chondrosarcomas are a group of malignant neoplasms with cartilaginous matrix production mostly found in flat and peripheral long bones. Mesenchymal chondrosarcoma is one of the most unusual and rare histological variants of chondrosarcoma, with a distinct histopathological appearance and biologically aggressive behavior. The amount of cartilage in mesenchymal chondrosarcoma may be so abundant that it is easily found in random sections or so scarce that numerous sections are required to discover it. In such cases, it is tough to make an accurate diagnosis, which leads to a big dilemma for pathologists and surgeons regarding diagnosis and treatment. Here, we report a mandibular mesenchymal chondrosarcoma in a 38-year-old male with a diagnosis of malignant small round cell tumor in incisional biopsy without any bone or chondroid formation. After ruling out lymphoma, a complete lesion excision was done. Diagnosis of mesenchymal chondrosarcoma was confirmed with small foci of chondroid material and strong positivity of tumoral cells for CD99 and S100. We highlight the fact that incisional biopsy frequently fails to provide sufficient tissue to establish the diagnosis of mesenchymal chondrosarcoma. Adequate tissue with multiple sections, detailed histopathological examination, and adjunctive IHC study are the keys to a definitive diagnosis.

Molecular insights and functional analysis of isocitrate dehydrogenase in two gram-negative pathogenic bacteria

Klebsiella pneumoniae and Legionella pneumophila are common Gram-negative bacteria that can cause lung infections. The multidrug resistance of K. pneumoniae presents a significant challenge for treatment. This study focuses on isocitrate dehydrogenase (IDH), a key enzyme in the oxidative metabolic pathway of these two bacteria. KpIDH and LpIDH were successfully overexpressed and purified, and their biochemical characteristics were thoroughly investigated. The study revealed that KpIDH and LpIDH are homodimeric enzymes with molecular weights of approximately 70 kDa. They are completely dependent on the coenzyme NADP+ and are inactive towards NAD+. KpIDH exhibits the highest catalytic activity at pH 8.0 in the presence of Mn2+ and at pH 7.8 in the presence of Mg2+. Its optimal catalytic performance is achieved with both ions at 55 °C. LpIDH exhibited its highest activity at pH 7.8 in the presence of Mn2+ and Mg2+, respectively, and exhibits optimal catalytic performance at 45 °C. Heat inactivation studies showed that KpIDH and LpIDH retained over 80% of their activity after being exposed to 45 °C for 20 min. Furthermore, we successfully altered the coenzyme specificity of KpIDH and LpIDH from NADP+ to NAD+ by replacing four key amino acid residues. This study provides a comprehensive biochemical characterization of two multidrug-resistant bacterial IDHs commonly found in hospital environments. It enhances our understanding of the characteristics of pathogenic bacteria and serves as a reference for developing new therapeutic strategies.

Mitochondrial signaling pathways and their role in cancer drug resistance

Mitochondria, traditionally known as cellular powerhouses, now emerge as critical signaling centers influencing cancer progression and drug resistance. The review highlights the role that apoptotic signaling, DNA mutations, mitochondrial dynamics and metabolism play in the development of resistance mechanisms and the advancement of cancer. Targeted approaches are discussed, with an emphasis on managing mitophagy, fusion, and fission of the mitochondria to make resistant cancer cells more susceptible to traditional treatments. Additionally, metabolic reprogramming can be used to effectively target metabolic enzymes such GLUT1, HKII, PDK, and PKM2 in order to avoid resistance mechanisms. Although there are potential possibilities for therapy, the complex structure of mitochondria and their subtle role in tumor development hamper clinical translation. Novel targeted medicines are put forth, providing fresh insights on combating drug resistance in cancer. The study also emphasizes the significance of glutamine metabolism, mitochondrial respiratory complexes, and apoptotic pathways as potential targets to improve treatment effectiveness against drug-resistant cancers. Combining complementary and nanoparticle-based techniques to target mitochondria has demonstrated encouraging results in the treatment of cancer, opening doors to reduce resistance and enable individualized treatment plans catered to the unique characteristics of each patient. Suggesting innovative approaches such as drug repositioning and mitochondrial drug delivery to enhance the efficacy of mitochondria-targeting therapies, presenting a pathway for advancements in cancer treatment. This thorough investigation is a major step forward in the treatment of cancer and has the potential to influence clinical practice and enhance patient outcomes.

Ollier Disease, Acute Myeloid Leukemia, and Brain Glioma: IDH as the Common Denominator

Ollier disease (OD), acute myeloid leukemia (AML), and brain glioma (BG) are three apparently completely different neoplasms in terms of histopathology, clinic, natural history, and management, but they can affect the same patient. This study aimed to identify the common molecular pathways involved in the pathogenesis of all three diseases and discuss their current and potential role as therapeutic targets. A detailed and comprehensive systematic literature review according to PRISMA guidelines on OD patients harboring BG and/or AML was made. In addition, the unique case of a patient affected by all three considered diseases has been added to our case series. Demographic, pathological, treatment, and outcome data were analyzed and discussed, mainly focusing on the molecular findings. Twenty-eight studies reported thirty-three patients affected by OD and BG, and only one study reported one patient with OD and AML, while only our patient harbored all three pathologies. The IDH R132H mutation was the only genetic alteration shared by all three pathologies and was simultaneously detected in enchondromas and brain glioma in 100% (3/3) of OD patients with BG and also in the neoplastic blood cells of the single patient hosting all three diseases. The IDH1-R132H gene mutation is the etiopathogenetic common denominator among three apparently different tumors coexisting in the same patient. The adoption of mutant-specific IDH1 inhibitor molecules could represent a potential panacea for these conditions in the era of targeted therapies. Further studies with larger clinical series are needed to confirm our results and hypothesis.

Discovery of novel natural-product-derived mutant isocitrate dehydrogenases 1 inhibitors: Structure-based virtual screening, biological evaluation and structure-activity relationship study

Mutations in IDH1 are commonly observed across various cancers, causing the conversion of α-KG to 2-HG. Elevated levels of 2-HG disrupt histone and DNA demethylation processes, promoting tumor development. Consequently, there is substantial interest in developing small molecule inhibitors targeting the mutant enzymes. Herein, we report a structure-based high-throughput virtual screening strategy using a natural products library, followed by hit-to-lead optimization. Through this process, we discover a potent compound, named 11s, which exhibited significant inhibition to IDH1 R132H and IDH1 R132C with IC50 values of 124.4 and 95.7 nM, respectively. Furthermore, 11s effectively reduced 2-HG formation, with EC50 values of 182 nM in U87 R132H cell, and 84 nM in HT-1080 cell. In addition, 11s significantly reduced U87 R132H and HT-1080 cell proliferation with GC50 values of 3.48 and 1.38 μM, respectively. PK-PD experiments further confirmed that compound 11s significantly decreased 2-HG formation in an HT-1080 xenograft mouse model, resulting in notable suppression of tumor growth without apparent loss in body weight.

Preparation and Preclinical Evaluation of 18F-Labeled Olutasidenib Derivatives for Non-Invasive Detection of Mutated Isocitrate Dehydrogenase 1 (mIDH1)

Mutations of isocitrate dehydrogenase 1 (IDH1) are key biomarkers for glioma classification, but current methods for detection of mutated IDH1 (mIDH1) require invasive tissue sampling and cannot be used for longitudinal studies. Positron emission tomography (PET) imaging with mIDH1-selective radioligands is a promising alternative approach that could enable non-invasive assessment of the IDH status. In the present work, we developed efficient protocols for the preparation of four 18F-labeled derivatives of the mIDH1-selective inhibitor olutasidenib. All four probes were characterized by cellular uptake studies with U87 glioma cells harboring a heterozygous IDH1 mutation (U87-mIDH) and the corresponding wildtype cells (U87-WT). In addition, the most promising probe was evaluated by PET imaging in healthy mice and mice bearing subcutaneous U87-mIDH and U87-WT tumors. Although all four probes inhibited mIDH1 with variable potencies, only one of them ([18F]mIDH-138) showed significantly higher in vitro uptake into U87-mIDH compared to U87-WT cells. In addition, PET imaging with [18F]mIDH-138 in mice demonstrated good in vivo stability and low non-specific uptake of the probe, but also revealed significantly higher uptake into U87-WT compared to U87-mIDH tumors. Finally, application of a two-tissue compartment model (2TCM) to the PET data indicated that preferential tracer uptake into U87-WT tumors results from higher specific binding rather than from differences in tracer perfusion. In conclusion, these results corroborate recent findings that mIDH1-selective inhibition may not directly correlate with mIDH1-selective target engagement and indicate that in vivo engagement of wildtype and mutated IDH1 may be governed by factors that are not faithfully reproduced by in vitro assays, both of which could complicate development of PET probes.

Molecular confirmation that fibrocartilaginous dysplasia is a variant of fibrous dysplasia

AIMS

Fibrocartilaginous dysplasia (FCD) is a subvariant of fibrous dysplasia (FD). This study aims to retrospectively elucidate the clinicopathological and separate genetic features of the cartilaginous and fibro-osseous components of FCD.

METHODS

In total, 24 patients (14 men and 10 women) with FCD were included in our cohort. The diagnosis was confirmed morphologically and immunohistochemically, and genetic features were determined via Sanger sequencing.

RESULTS

Five patients were polyostotic, and 19 were monostotic, predominantly concerning the femur. Radiography revealed a well-demarcated ground glass appearance with ring-like or scattered calcification. Histologically, the lesions were characterised by proliferative fibroblasts, immature woven bone and highly differentiated hyaline cartilage. The fibro-osseous components exhibited positive immunoreaction with SATB2 and a low Ki-67 proliferation index. The fibro-osseous and cartilaginous components shared mutations at codon 201 in exon 8 of the guanine nucleotide-binding protein/a-subunit (GNAS) gene, specifically CGT>CAT (p.R201H) in four patients and the wild-type isocitrate dehydrogenase (IDH)1/IDH2 gene. Telomerase reverse transcriptase (TERT) promoter mutations (C288T and C229G) occurred in both fibro-osseous and cartilaginous components in two patients.

CONCLUSIONS

FCD encompasses areas of conventional FD with additional cartilage. Importantly, the presence or absence of mutations in the GNAS gene and/or the TERT promoter is common between the fibro-osseous and cartilaginous components of the disease. These results further confirmed FCD as a variant of FD.

A perioperative study of Safusidenib in patients with IDH1-mutated glioma

This is a single arm, open label perioperative trial to assess the feasibility, pharmacokinetics and pharmacodynamics of treatment with safusidenib following biopsy, and prior to surgical resection in patients with IDH1 mutated glioma who have not received radiation therapy or chemotherapy. Fifteen participants will receive treatment in two parts. First, biopsy followed by one cycle (28 days) of safusidenib, an orally available, small molecular inhibitor of mutated IDH1, then maximal safe resection of the tumor (Part A). Second, after recovery from surgery, safusidenib until disease progression or unacceptable toxicity (Part B). This research will enable objective measurement of biological activity of safusidenib in patients with IDH1 mutated glioma. Anti-tumor activity will be assessed by progression free survival and time to next intervention.Clinical Trial Registration: NCT05577416 (ClinicalTrials.gov).

Current advance of nanotechnology in diagnosis and treatment for malignant tumors

Cancer remains a significant risk to human health. Nanomedicine is a new multidisciplinary field that is garnering a lot of interest and investigation. Nanomedicine shows great potential for cancer diagnosis and treatment. Specifically engineered nanoparticles can be employed as contrast agents in cancer diagnostics to enable high sensitivity and high-resolution tumor detection by imaging examinations. Novel approaches for tumor labeling and detection are also made possible by the use of nanoprobes and nanobiosensors. The achievement of targeted medication delivery in cancer therapy can be accomplished through the rational design and manufacture of nanodrug carriers. Nanoparticles have the capability to effectively transport medications or gene fragments to tumor tissues via passive or active targeting processes, thus enhancing treatment outcomes while minimizing harm to healthy tissues. Simultaneously, nanoparticles can be employed in the context of radiation sensitization and photothermal therapy to enhance the therapeutic efficacy of malignant tumors. This review presents a literature overview and summary of how nanotechnology is used in the diagnosis and treatment of malignant tumors. According to oncological diseases originating from different systems of the body and combining the pathophysiological features of cancers at different sites, we review the most recent developments in nanotechnology applications. Finally, we briefly discuss the prospects and challenges of nanotechnology in cancer.

Targeting Isocitrate Dehydrogenase (IDH) in Solid Tumors: Current Evidence and Future Perspectives

The isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) enzymes are involved in key metabolic processes in human cells, regulating differentiation, proliferation, and oxidative damage response. IDH mutations have been associated with tumor development and progression in various solid tumors such as glioma, cholangiocarcinoma, chondrosarcoma, and other tumor types and have become crucial markers in molecular classification and prognostic assessment. The intratumoral and serum levels of D-2-hydroxyglutarate (D-2-HG) could serve as diagnostic biomarkers for identifying IDH mutant (IDHmut) tumors. As a result, an increasing number of clinical trials are evaluating targeted treatments for IDH1/IDH2 mutations. Recent studies have shown that the focus of these new therapeutic strategies is not only the neomorphic activity of the IDHmut enzymes but also the epigenetic shift induced by IDH mutations and the potential role of combination treatments. Here, we provide an overview of the current knowledge about IDH mutations in solid tumors, with a particular focus on available IDH-targeted treatments and emerging results from clinical trials aiming to explore IDHmut tumor-specific features and to identify the clinical benefit of IDH-targeted therapies and their combination strategies. An insight into future perspectives and the emerging roles of circulating biomarkers and radiomic features is also included.

Global research development of chondrosarcoma from 2003 to 2022: a bibliometric analysis

Background

Chondrosarcomas are common primary malignant bone tumors; however, comprehensive bibliometric analysis in this field has not yet been conducted. Therefore, this study aimed to explore the research hotspots and trends in the field of chondrosarcoma through bibliometric analysis to help researchers understand the current status and direction of research in the field.

Methods

Articles and reviews related to chondrosarcoma published between 2003 and 2022 were retrieved from the Web of Science. Countries, institutions, authors, journals, references, and keywords in this field were visualized and analyzed using CtieSpace and VOSviewer software.

Results

Between 2003 and 2022, 4,149 relevant articles were found. The number of articles published on chondrosarcoma has increased significantly annually, mainly from 569 institutions in China and the United States, and 81 in other countries. In total, 904 authors participated in the publication of studies related to chondrosarcomas. Over the past 20 years, articles on chondrosarcoma have been published in 958 academic journals, with Skeletal Radiology having the highest number of publications. Furthermore, keywords such as "gene expression," "radiotherapy," "experience," and "apoptosis" have been popular in recent years.

Conclusion

Over the past 20 years, the global trend in chondrosarcoma research has primarily been clinical research, with basic research as a supplement. In the future, communication and exchange between countries and institutions should be strengthened. Further, the future main research hotspots in the field of chondrosarcoma include mutated genes and signaling pathways, precision surgical treatment, proton therapy, radiation therapy, chemotherapy, immunotherapy, and other aspects.

The Leukemic Isocitrate Dehydrogenase (IDH) 1/2 Mutations Impair Myeloid and Erythroid Cell Differentiation of Primary Human Hematopoietic Stem and Progenitor Cells (HSPCs)

How hematopoietic stem and progenitor cell (HSPC) fate decisions are affected by genetic alterations acquired during AML leukemogenesis is poorly understood and mainly explored in animal models. Here, we study isocitrate dehydrogenase (IDH) gene mutations in the human model of HSPC and discuss the available literature on this topic. IDH1/2 mutations occur in ~20% of AML cases, are recognized among the mutations earliest acquired during leukemogenesis, and are targets of specific inhibitors (ivosidenib and enasidenib, respectively). In order to investigate the direct effects of these mutations on HSPCs, we expressed IDH1-R132H or IDH2-R140Q mutants into human CD34+ healthy donor cells via lentiviral transduction and analyzed the colony-forming unit (CFU) ability. CFU ability was dramatically compromised with a complete trilineage block of differentiation. Strikingly, the block was reversed by specific inhibitors, confirming that it was a specific effect induced by the mutants. In line with this observation, the CD34+ leukemic precursors isolated from a patient with IDH2-mutated AML at baseline and during enasidenib treatment showed progressive and marked improvements in their fitness over time, in terms of CFU ability and propensity to differentiate. They attained clonal trilinear reconstitution of hematopoiesis and complete hematological remission.

[Malignant transformation of Ollier disease-related multiple glioma with IDH1 p.R132C mutation]

A 21-year-old man who was diagnosed with Ollier disease at the age of 1 year developed incidental multiple gliomas at the age of 15 years. Subsequently, the multiple gliomas enlarged and the patient underwent three surgical removals. Genetic analysis revealed the IDH1 p.R132C mutation in the gliomas, and histopathology showed malignant transformation. Despite multimodality treatment, the gliomas could not be controlled, and the patient died at the age of 23 years. Ollier disease is a rare disease with IDH1/2 mutations and is often associated with gliomas. However, there are very few reports on genetic analysis of IDH1/2 mutations and long-term follow-up in Ollier disease-related gliomas. Genetic analysis of IDH mutations may contribute to the elucidation of its pathogenesis. The cross-departmental collaboration is required for long-term follow-up of Ollier disease-related gliomas.

Targeting DNA Methylation Machinery in Pediatric Solid Tumors

DNA methylation is a key epigenetic regulatory mechanism that plays a critical role in a variety of cellular processes, including the regulation of cell fate during development, maintenance of cell identity, and genome stability. DNA methylation is tightly regulated by enzymatic reactions and its deregulation plays an important role in the development of cancer. Specific DNA methylation alterations have been found in pediatric solid tumors, providing new insights into the development of these tumors. In addition, DNA methylation profiles have greatly contributed to tune the diagnosis of pediatric solid tumors and to define subgroups of patients with different risks of progression, leading to the reduction in unwanted toxicity and the improvement of treatment efficacy. This review highlights the dysregulated DNA methylome in pediatric solid tumors and how this information provides promising targets for epigenetic therapies, particularly inhibitors of DNMT enzymes (DNMTis). Opportunities and limitations are considered, including the ability of DNMTis to induce viral mimicry and immune signaling by tumors. Besides intrinsic action against cancer cells, DNMTis have the potential to sensitize immune-cold tumors to immunotherapies and may represent a remarkable option to improve the treatment of challenging pediatric solid tumors.

DNA methylation in human diseases

Aberrant epigenetic modifications, particularly DNA methylation, play a critical role in the pathogenesis and progression of human diseases. The current review aims to reveal the role of aberrant DNA methylation in the pathogenesis and progression of diseases and to discuss the original data obtained from international research laboratories on this topic. In the review, we mainly summarize the studies exploring the role of aberrant DNA methylation as diagnostic and prognostic biomarkers in a broad range of human diseases, including monogenic epigenetics, autoimmunity, metabolic disorders, hematologic neoplasms, and solid tumors. The last section provides a general overview of the possibility of the DNA methylation machinery from the perspective of pharmaceutic approaches. In conclusion, the study of DNA methylation machinery is a phenomenal intersection that each of its ways can reveal the mysteries of various diseases, introduce new diagnostic and prognostic biomarkers, and propose a new patient-tailored therapeutic approach for diseases.

The Tricarboxylic Acid Cycle Metabolites for Cancer: Friend or Enemy

The tricarboxylic acid (TCA) cycle is capable of providing sufficient energy for the physiological activities under aerobic conditions. Although tumor metabolic reprogramming places aerobic glycolysis in a dominant position, the TCA cycle remains indispensable for tumor cells as a hub for the metabolic linkage and interconversion of glucose, lipids, and certain amino acids. TCA intermediates such as citrate, α-ketoglutarate, succinate, and fumarate are altered in tumors, and they regulate the tumor metabolism, signal transduction, and immune environment to affect tumorigenesis and tumor progression. This article provides a comprehensive review of the modifications occurring in tumor cells in relation to the intermediates of the TCA cycle, which affects tumor pathogenesis and current therapeutic strategy for therapy through targeting TCA cycle in cancer cells.

Single-cell transcriptomic analyses of mouse idh1 mutant growth plate chondrocytes reveal distinct cell populations responsible for longitudinal growth and enchondroma formation

Enchondromas are a common tumor in bone that can occur as multiple lesions in enchondromatosis, which is associated with deformity of the effected bone. These lesions harbor mutations in IDH and driving expression of a mutant Idh1 in Col2 expressing cells in mice causes an enchondromatosis phenotype. In this study we compared growth plates from E18.5 mice expressing a mutant Idh1 with control littermates using single cell RNA sequencing. Data from Col2 expressing cells were analyzed using UMAP and RNA pseudo-time analyses. A unique cluster of cells was identified in the mutant growth plates that expressed genes known to be upregulated in enchondromas. There was also a cluster of cells that was underrepresented in the mutant growth plates that expressed genes known to be important in longitudinal bone growth. Immunofluorescence showed that the genes from the unique cluster identified in the mutant growth plates were expressed in multiple growth plate anatomic zones, and pseudo-time analysis also suggested these cells could arise from multiple growth plate chondrocyte subpopulations. This data identifies subpopulations of cells in control and mutant growth plates, and supports the notion that a mutant Idh1 alters the subpopulations of growth plate chondrocytes, resulting a subpopulation of cells that become enchondromas at the expense of other populations that contribute to longitudinal growth.

Dedifferentiation in bone and soft tissue sarcomas: How do we define it? What is prognostically relevant?

Dedifferentiation traditionally is defined by descriptive criteria as a tumor showing an abrupt change in histology from a conventional, classic, low-grade appearing neoplasm to a tumor that is more cellular, pleomorphic and "high grade", with grading typically being performed by subjective criteria. The dedifferentiated areas range from areas with recognizable histologic differentiation which differs from the primary tumor (such as an osteosarcoma arising from a low-grade chondrosarcoma) to areas containing sarcomas without specific histologic differentiation (such as pleomorphic or spindle cell sarcoma). Many, but not all, dedifferentiated tumors are aggressive and associated with significantly shorter survival than their conventional counterparts, even grade 3 conventional tumors. As a result, dedifferentiated tumors are generally considered to be clinically aggressive and as a result, more aggressive surgery or the addition of (neo)adjuvant chemotherapy is often considered. However, long-term (greater than 20 year) survivors are reported in the most common dedifferentiated bone and soft tissue sarcomas. Moreover, use of mitotic criterion for defining dedifferentiation in dedifferentiated liposarcoma as well as grading (by the French system) have been found to be associated with survival. This paper reviews the literature on dedifferentiated chondrosarcoma, dedifferentiated liposarcoma, dedifferentiated chordoma and dedifferentiated parosteal osteosarcoma. As a result of that review, recommendations are advocated to identify evidence-based, objective diagnostic and grading criteria for dedifferentiation that are appropriate for each tumor type. Adding such criteria will improve consistency in diagnosis worldwide, allow easier comparison of clinical research performed on dedifferentiated tumors and help communicate (to patients and clinicians) the tumors with highest risk of clinically aggressive behavior, to allow appropriate and personalized treatment planning.

Management of isocitrate dehydrogenase 1/2 mutated acute myeloid leukemia

The emergence of next generation sequencing and widespread use of mutational profiling in acute myeloid leukemia (AML) has broadened our understanding of the heterogeneous molecular basis of the disease. Since genetic sequencing has become a standard practice, several driver mutations have been identified. Accordingly, novel targeted therapeutic agents have been developed and are now approved for the treatment of subsets of patients that carry mutations in FLT3, IDH1, and IDH2 [1, 2]. The emergence of these novel agents in AML offers patients a new modality of therapy, and shifts treatment paradigms toward individualized medicine. In this review, we outline the role of IDH mutations in malignant transformation, focus in on a novel group of targeted therapeutic agents directed toward IDH1- and IDH2-mutant AML, and explore their impact on prognosis in patients with AML.

Resolving Challenges in Detection and Quantification of D-2-hydroxyglutarate and L-2-hydroxyglutarate via LC/MS

D-2-Hydroxyglutarate and L-2-Hydroxyglutarate (D-2HG/L-2HG) are typically metabolites of non-specific enzymatic reactions that are kept in check by the housekeeping enzymes, D-2HG /L-2HG dehydrogenase (D-2HGDH/L-2HGDH). In certain disease states, such as D-2HG or L-2HG aciduria and cancers, accumulation of these biomarkers interferes with oxoglutarate-dependent enzymes that regulate bioenergetic metabolism, histone methylation, post-translational modification, protein expression and others. D-2HG has a complex role in tumorigenesis that drives metabolomics investigations. Meanwhile, L-2HG is produced by non-specific action of malate dehydrogenase and lactate dehydrogenase under acidic or hypoxic environments. Characterization of divergent effects of D-2HG/L-2HG on the activity of specific enzymes in diseased metabolism depends on their accurate quantification via mass spectrometry. Despite advancements in high-resolution quadrupole time-of-flight mass spectrometry (HR-QTOF-MS), challenges are typically encountered when attempting to resolve of isobaric and isomeric metabolites such as D-2HG/L-2HG for quantitative analysis. Herein, available D-2HG/L-2HG derivatization and liquid chromatography (LC) MS quantification methods were examined. The outcome led to the development of a robust, high-throughput HR-QTOF-LC/MS approach that permits concomitant quantification of the D-2HG and L-2HG enantiomers with the benefit to quantify the dysregulation of other intermediates within interconnecting pathways. Calibration curve was obtained over the linear range of 0.8-104 nmol/mL with r 2 ≥ 0.995 for each enantiomer. The LC/MS-based assay had an overall precision with intra-day CV % ≤ 8.0 and inter-day CV % ≤ 6.3 across the quality control level for commercial standard and pooled biological samples; relative error % ≤ 2.7 for accuracy; and resolution, R s = 1.6 between 2HG enantiomers (m/z 147.030), D-2HG and L-2HG (at retention time of 5.82 min and 4.75 min, respectively) following chiral derivatization with diacetyl-L-tartaric anhydride (DATAN). Our methodology was applied to disease relevant samples to illustrate the implications of proper enantioselective quantification of both D-2HG and L-2HG. The stability of the method allows scaling to large cohorts of clinical samples in the future.

A personalized medicine approach identifies enasidenib as an efficient treatment for IDH2 mutant chondrosarcoma

BACKGROUND

Sarcomas represent an extensive group of malignant diseases affecting mesodermal tissues. Among sarcomas, the clinical management of chondrosarcomas remains a complex challenge, as high-grade tumours do not respond to current therapies. Mutations in the isocitrate dehydrogenase (IDH) 1 and 2 genes are among the most common mutations detected in chondrosarcomas and may represent a therapeutic opportunity. The presence of mutated IDH (mIDH) enzymes results in the accumulation of the oncometabolite 2-HG leading to molecular alterations that contribute to drive tumour growth.

METHODS

We developed a personalized medicine strategy based on the targeted NGS/Sanger sequencing of sarcoma samples (n = 6) and the use of matched patient-derived cell lines as a drug-testing platform. The anti-tumour potential of IDH mutations found in two chondrosarcoma cases was analysed in vitro, in vivo and molecularly (transcriptomic and DNA methylation analyses).

FINDINGS

We treated several chondrosarcoma models with specific mIDH1/2 inhibitors. Among these treatments, only the mIDH2 inhibitor enasidenib was able to decrease 2-HG levels and efficiently reduce the viability of mIDH2 chondrosarcoma cells. Importantly, oral administration of enasidenib in xenografted mice resulted in a complete abrogation of tumour growth. Enasidenib induced a profound remodelling of the transcriptomic landscape not associated to changes in the 5 mC methylation levels and its anti-tumour effects were associated with the repression of proliferative pathways such as those controlled by E2F factors.

INTERPRETATION

Overall, this work provides preclinical evidence for the use of enasidenib to treat mIDH2 chondrosarcomas.

FUNDING

Supported by the Spanish Research Agency/FEDER (grants PID2022-142020OB-I00; PID2019-106666RB-I00), the ISC III/FEDER (PI20CIII/00020; DTS18CIII/00005; CB16/12/00390; CB06/07/1009; CB19/07/00057); the GEIS group (GEIS-62); and the PCTI (Asturias)/FEDER (IDI/2021/000027).

Opportunity in Complexity: Harnessing Molecular Biomarkers and Liquid Biopsies for Personalized Sarcoma Care

Due to their rarity and complexity, sarcomas represent a substantial therapeutic challenge. However, the incredible diversity within and across sarcoma subtypes presents an opportunity for personalized care to maximize efficacy and limit toxicity. A deeper understanding of the molecular alterations that drive sarcoma development and treatment response has paved the way for molecular biomarkers to shape sarcoma treatment. Genetic, transcriptomic, and protein biomarkers have become critical tools for diagnosis, prognostication, and treatment selection in patients with sarcomas. In the future, emerging biomarkers like circulating tumor DNA analysis offer the potential to improve early detection, monitoring response to treatment, and identifying mechanisms of resistance to personalize sarcoma treatment. Here, we review the current state of molecular biomarkers for sarcomas and highlight opportunities and challenges for the implementation of new technologies in the future.

Integrated Molecular and Histological Insights for Targeted Therapies in Mesenchymal Sinonasal Tract Tumors

PURPOSE OF REVIEW

This review aims to provide a comprehensive overview of mesenchymal sinonasal tract tumors (STTs), a distinct subset of STTs. Despite their rarity, mesenchymal STTs represent a unique clinical challenge, characterized by their rarity, often slow progression, and frequently subtle or overlooked symptoms. The complex anatomy of the sinonasal area, which includes critical structures such as the orbit, brain, and cranial nerves, further complicates surgical treatment options. This underscores an urgent need for more advanced and specialized therapeutic approaches.

RECENT FINDINGS

Advancements in molecular diagnostics, particularly in next-generation sequencing, have significantly enhanced our understanding of STTs. Consequently, the World Health Organization has updated its tumor classification to better reflect the distinct histological and molecular profiles of these tumors, as well as to categorize mesenchymal STTs with greater accuracy. The growing understanding of the molecular characteristics of mesenchymal STTs opens new possibilities for targeted therapeutic interventions, marking a significant shift in treatment paradigms. This review article concentrates on mesenchymal STTs, specifically addressing sinonasal tract angiofibroma, sinonasal glomangiopericytoma, biphenotypic sinonasal sarcoma, and skull base chordoma. These entities are marked by unique histopathological and molecular features, which challenge conventional treatment approaches and simultaneously open avenues for novel targeted therapies. Our discussion is geared towards delineating the molecular underpinnings of mesenchymal STTs, with the objective of enhancing therapeutic strategies and addressing the existing shortcomings in the management of these intricate tumors.

Advancing the Management of Skull Base Chondrosarcomas: A Systematic Review of Targeted Therapies

Background: Chondrosarcomas rank as the second most common primary bone malignancy. Characterized by the production of a cartilaginous matrix, these tumors typically exhibit resistance to both radiotherapy (RT) and chemotherapy (CT), resulting in overall poor outcomes: a high rate of mortality, especially among children and adolescents. Due to the considerable resistance to current conventional therapies such as surgery, CT, and RT, there is an urgent need to identify factors contributing to resistance and discover new strategies for optimal treatment. Over the past decade, researchers have delved into the dysregulation of genes associated with tumor development and therapy resistance to identify potential therapeutic targets for overcoming resistance. Recent studies have suggested several promising biomarkers and therapeutic targets for chondrosarcoma, including isocitrate dehydrogenase (IDH1/2) and COL2A1. Molecule-targeting agents and immunotherapies have demonstrated favorable antitumor activity in clinical studies involving patients with advanced chondrosarcomas. In this systematic review, we delineate the clinical features of chondrosarcoma and provide a summary of gene dysregulation and mutation associated with tumor development, as well as targeted therapies as a promising molecular approach. Finally, we analyze the probable role of the tumor microenvironment in chondrosarcoma drug resistance. Methods: A systematic search was conducted across major medical databases (PubMed, Embase, and Cochrane Library) up to 10 November 2023. The search strategy utilized relevant Medical Subject Heading (MeSH) terms and keywords related to “chondrosarcomas”, “target therapies”, “immunotherapies”, and “outcomes”. The studies included in this review consist of randomized controlled trials, non-randomized controlled trials, and cohort studies reporting on the use of target therapies for the treatment of chondrosarcoma in human subjects. Results: Of the initial 279 articles identified, 40 articles were included in the article. The exclusion of 140 articles was due to reasons such as irrelevance, non-reporting of selected results, systematic literature review or meta-analysis, and lack of details on the method/results. Three tables highlighted clinical studies, preclinical studies, and ongoing clinical trials, encompassing 13, 7, and 20 studies, respectively. For the clinical study, a range of molecular targets, such as death receptors 4/5 (DR4 and DR5) (15%), platelet-derived growth factor receptor-alpha or -beta (PDGFR-α, PDGFR-β) (31%), were investigated. Adverse events were mainly constitutional symptoms emphasizing that to improve therapy tolerance, careful observation and tailored management are essential. Preclinical studies analyzed various molecular targets such as DR4/5 (28.6%) and COX-2 (28.6%). The prevalent indicator of antitumoral activity was the apoptotic rate of both a single agent (tumor necrosis factor-related apoptosis-inducing ligand: TRAIL) and double agents (TRAIL-DOX, TRAIL-MG132). Ongoing clinical trials, the majority in Phase II (53.9%), highlighted possible therapeutic strategies such as IDH1 inhibitors and PD-1/PD-L1 inhibitors (30.8%). Conclusions: The present review offers a comprehensive analysis of targeted therapeutics for skull base chondrosarcomas, highlighting a complex landscape characterized by a range of treatment approaches and new opportunities for tailored interventions. The combination of results from molecular research and clinical trials emphasizes the necessity for specialized treatment strategies and the complexity of chondrosarcoma biology.

IDH1-mutated Crohn's disease-associated small bowel adenocarcinomas: Distinctive pathological features and association with MGMT methylation and serrated-type dysplasia

AIMS

Patients with Crohn's disease (CrD) have an elevated risk for the development of small bowel adenocarcinomas (SBAs). Actionable isocitrate dehydrogenase 1 (IDH1) mutations have been reported to be more frequent in CrD-SBAs than in sporadic SBAs. The present study aimed to investigate the clinicopathological and immunophenotypical features, as well as methylation profiles, of IDH1-mutated CrD-SBAs.

METHODS AND RESULTS

An international multicentre series of surgically resected CrD-SBAs was tested for IDH1 mutation. Clinicopathological features, immunophenotypical marker expression and O6-methylguanine-DNA methyltransferase (MGMT) and long interspersed nuclear element-1 (LINE-1) methylation were compared between IDH1-mutated and IDH1 wild-type CrD-SBAs. Ten (20%) of the 49 CrD-SBAs examined harboured an IDH1 mutation and all the mutated cancers harboured the R132C variant. Compared to IDH1 wild-type cases, IDH1-mutated CrD-SBAs showed significantly lower rates of cytokeratin 7 expression (P = 0.005) and higher rates of p53 overexpression (P = 0.012) and MGMT methylation (P = 0.012). All three dysplastic growths associated with IDH1-mutated SBAs harboured the same IDH1 variant (R132C) of the corresponding invasive cancer, and all were of non-conventional subtype (two serrated dysplastic lesions and one goblet cell-deficient dysplasia). In particular, non-conventional serrated dysplasia was significantly associated with IDH1-mutated CrD-SBAs (P = 0.029). No significant cancer-specific survival difference between IDH1-mutated CrD-SBA patients and IDH1 wild-type CrD-SBA patients was found (hazard ratio = 0.55, 95% confidence interval = 0.16-1.89; P = 0.313).

CONCLUSIONS

IDH1-mutated CrD-SBAs, which represent approximately one-fifth of total cases, are characterised by distinctive immunophenotypical features and methylation profiles, with potential therapeutic implications. Moreover, IDH1-mutated non-conventional, serrated dysplasia is likely to represent a precursor lesion to such CrD-SBAs.

Oncometabolite 2-hydroxyglutarate regulates anti-tumor immunity

"Oncometabolite" 2-hydroxyglutarate (2-HG) is an aberrant metabolite found in tumor cells, exerting a pivotal influence on tumor progression. Recent studies have unveiled its impact on the proliferation, activation, and differentiation of anti-tumor T cells. Moreover, 2-HG regulates the function of innate immune components, including macrophages, dendritic cells, natural killer cells, and the complement system. Elevated levels of 2-HG hinder α-KG-dependent dioxygenases (α-KGDDs), contributing to tumorigenesis by disrupting epigenetic regulation, genome integrity, hypoxia-inducible factors (HIF) signaling, and cellular metabolism. The chiral molecular structure of 2-HG produces two enantiomers: D-2-HG and L-2-HG, each with distinct origins and biological functions. Efforts to inhibit D-2-HG and leverage the potential of L-2-HG have demonstrated efficacy in cancer immunotherapy. This review delves into the metabolism, biological functions, and impacts on the tumor immune microenvironment (TIME) of 2-HG, providing a comprehensive exploration of the intricate relationship between 2-HG and antitumor immunity. Additionally, we examine the potential clinical applications of targeted therapy for 2-HG, highlighting recent breakthroughs as well as the existing challenges.

A single-cell atlas of conventional central chondrosarcoma reveals the role of endoplasmic reticulum stress in malignant transformation

The transformation of benign lesions to malignant tumours is a crucial aspect of understanding chondrosarcomas, which are malignant cartilage tumours that could develop from benign chondroid lesions. However, the process of malignant transformation for chondroid lesions remains poorly understood, and no reliable markers are available to aid clinical decision-making. To address this issue, we conducted a study analysing 11 primary cartilage tumours and controls using single-cell RNA sequencing. By creating a single-cell atlas, we were able to identify the role of endoplasmic reticulum (ER) stress in the malignant transformation of conventional central chondrosarcomas (CCCS). Our research revealed that lower levels of ER stress promote chondrosarcoma growth in a patient-derived xenograft mouse model, while intensive ER stress reduces primary chondrosarcoma cell viability. Furthermore, we discovered that the NF-κB pathway alleviates ER stress-induced apoptosis during chondrosarcoma progression. Our single-cell signatures and large public data support the use of key ER stress regulators, such as DNA Damage Inducible Transcript 3 (DDIT3; also known as CHOP), as malignant markers for overall patient survival. Ultimately, our study highlights the significant role that ER stress plays in the malignant transformation of cartilaginous tumours and provides a valuable resource for future diagnostic markers and therapeutic strategies.

A Systematic Review of Adjuvant Chemotherapy in Localized Dedifferentiated Chondrosarcoma

Dedifferentiated chondrosarcoma (DDCS) is a high-grade subtype of chondrosarcoma with the bimorphic histological appearance of a conventional chondrosarcoma component with abrupt transition to a high-grade, non-cartilaginous sarcoma. DDCS can be radiographically divided into central and peripheral types. Wide resection is currently the main therapeutic option for localized DDCS. Moreover, the effectiveness of adjuvant chemotherapy remains controversial. Therefore, we performed a systematic review of available evidence to evaluate the effect of adjuvant chemotherapy on localized DDCS. The purpose was to compare the 5-year survival rate among patients treated with surgery plus adjuvant chemotherapy or surgery alone for localized DDCS. The search was conducted in PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Of the 217 studies shortlisted, 11 retrospective non-randomized studies (comprising 556 patients with localized DDCS) were selected. The 5-year survival rates were similar between the two treatment groups (28.2% (51/181) vs. 24.0% (90/375), respectively). The overall pooled odds ratio was 1.25 (95% confidence interval: 0.80-1.94; p = 0.324), and heterogeneity I2 was 2%. However, when limited to peripheral DDCS, adjuvant chemotherapy was associated with prolonged survival (p = 0.03). Due to the paucity of included studies and the absence of prospective comparative studies, no conclusions can be drawn regarding the effectiveness or ineffectiveness of adjuvant chemotherapy for localized DDCS.

SMARCB1-Deficient Skull Base Chondrosarcoma with 12p Duplication Presenting as Somatic-Type Malignancy Arising from Metastatic Seminoma

Somatic-type malignancy (STM) can occur infrequently within a primary or metastatic testicular germ cell tumor (TGCT) and is associated with dismal prognosis and survival. STM with chondrosarcomatous features is exceedingly rare and head and neck involvement has not been previously documented. A 39-year-old white man presented with nasal obstruction and epistaxis. Imaging disclosed a 6.9-cm expansile tumor involving the nasal cavity and skull base with intraorbital and intracranial extension. The histopathologic properties of the tumor were compatible with chondrosarcoma, grade II-III. Immunohistochemically, malignant cells were strongly and diffusely positive for S100 and epithelial markers, and showed loss of SMARCB1 expression. IDH1/2 mutations were not detected. Following whole-body PET scan, a 7.0-cm left testicular mass was discovered and diagnosed as seminoma with syncytiotrophoblastic cells, stage pT3NXM1b. Extensive retroperitoneal, mediastinal, and supraclavicular lymphadenopathy was also noticed. Histopathologic examination of the left supraclavicular lymph node revealed metastatic seminoma. By FISH, most metastatic nodal seminoma cells harbored 1 to 4 copies of isochromosome 12p, while the chondrosarcoma featured duplication of 12p. Presence of a malignant TGCT with disseminated supradiaphragmatic lymphadenopathy, the unique immunophenotypic properties of the skull-based chondrosarcoma and lack of IDH1/2 aberrations with gain of 12p strongly support the diagnosis of STM chondrosarcoma arising from metastatic TGCT. The patient did not respond to chemotherapy and succumbed three months after diagnosis. Although exceedingly uncommon, metastasis to the head and neck may occur in patients with TGCT. This case of STM chondrosarcoma demonstrated divergent immunophenotypic and molecular characteristics compared to "typical" examples of head and neck chondrosarcoma. High index of suspicion is advised regarding the diagnosis of lesions that present with otherwise typical histomorphology but unexpected immunohistochemical or molecular features.

Diagnostics of IDH1/2 Mutations in Intracranial Chondroid Tumors: Comparison of Molecular Genetic Methods and Immunohistochemistry

Intracranial chondroid tumors are a heterogeneous group of neoplasms characterized by the presence of a cartilage matrix. These tumors exhibit overlapping clinical and histological features. Mutations in IDH1/2 genes serve as important diagnostic markers of tumor type, particularly chondrosarcoma. To improve the accuracy of IDH1/2 diagnostics, we compared three methods: biochip assay, real-time PCR with DNA melting analysis using TaqMan probes and sequencing (qPCR-DMA-Sanger), and immunohistochemistry (IHC). Tumor samples from 96 patients were investigated. The IDH1 mutations were detected in 34/64 (53%) chondrosarcomas; IHC detected 27/56 (48.2%) mutations, the qPCR-DMA-Sanger method 27/59 (46%) mutations, and the biochip assay revealed 29/60 (48.3%) mutations. The detection of IDH1 mutations in chordoma (2/15) and osteosarcoma (2/7) suggested the need for a revised diagnosis. In benign tumors, IDH1 mutations were present in chondroma (4/6), but absent in chondromyxoid fibroma (0/4). The most frequent IDH1 mutations were R132C (60%), R132L, and R132G (13.5% each), R132H (8%), and R132S (5%). The concordance between the biochip assay and IHC was 90%, between IHC and PCR-DMA-Sanger 83%, and between biochip assay and qPCR-DMA-Sanger was 98%, respectively. No IDH2 mutations were found. The use of independent diagnostic methods may improve the detection of IDH-mutant specimens in chondroid tumors.

Hunting for the vulnerability in chondrosarcoma by tracing metabolic and genetic links

In this Backstory, we narrate our journey in establishing a multidisciplinary team for sarcoma research and uncovering vulnerabilities in chondrosarcoma cells associated with their NAD+ dependencies for survival.1 Our findings hold promise for exploitation, yielding a synergistic cytotoxic effect when combined with systemic therapy.

Grade 2, 3 and Dedifferentiated Chondrosarcomas: A Comparative Study of Isocitrate Dehydrogenase-Mutant and Wild-Type Tumors with Implications for Prognosis and Therapy

BACKGROUND

Grade 2 and 3 and dedifferentiated chondrosarcomas (CS) are frequently associated with isocitrate dehydrogenase (IDH) mutations and often exhibit a poor clinical outcome. Treatment is limited mainly to surgery. Defining IDH status (wild type (WT) and mutant) and the associated transcriptome may prove useful in determining other therapeutic options in these neoplasms.

METHODS

Formalin-fixed paraffin-embedded material from 69 primary and recurrent grade 2, 3 and dedifferentiated CS was obtained. DNA sequencing for IDH1 and IDH2 mutations (n = 47) and RNA sequencing via Nextseq 2000 (n = 14) were performed. Differentially expressed genes (DEGs) were identified and used to predict aberrant biological pathways with Ingenuity Pathway Analysis (IPA) software (Qiagen). Gene Set Enrichment Analyses (GSEA) using subsets C3, C5 and C7 were performed. Differentially expressed genes were validated by immunohistochemistry. Outcome analysis was performed using the Wilcoxon test.

RESULTS

A set of 69 CS (28 females, 41 males), average age 65, distributed among femur, pelvis, humerus, and chest wall were identified from available clinical material. After further selection based on available IDH status, we evaluated 15 IDH WT and 32 IDH mutant tumors as part of this dataset. Out of 15 IDH WT tumors, 7 involved the chest wall/scapula, while 1 of 32 mutants arose in the scapula. There were far more genes overexpressed in IDH WT tumors compared to IDH mutant tumors. Furthermore, IDH WT and IDH mutant tumors were transcriptomically distinct in the IPA and GSEA, with IDH mutant tumors showing increased activity in methylation pathways and endochondral ossification, while IDH WT tumors showed more activity in normal matrix development pathways. Validation immunohistochemistry demonstrated expression of WT1 and AR in IDH WT tumors, but not in IDH mutants. SATB2 was expressed in IDH mutant tumors and not in WT tumors. Outcome analysis revealed differences in overall survival between mutant and WT tumors (p = 0.04), dedifferentiated mutant and higher-grade (2, 3) mutant tumors (p = 0.03), and dedifferentiated mutant and higher-grade (2, 3) WT tumors (p = 0.03). The longest survival times were observed in patients with higher-grade WT tumors, while patients with dedifferentiated mutant tumors showed the lowest survival. Generally, patients with IDH WT tumors displayed longer survival in both the higher-grade and dedifferentiated groups.

CONCLUSIONS

Grade 2, 3 and dedifferentiated chondrosarcomas are further characterized by IDH status, which in turn informs transcriptomic phenotype and overall survival. The transcriptome is distinct depending on IDH status, and implies different treatment targets.