Molecular Pathogenesis and Diagnostic, Prognostic and Predictive Molecular Markers in Sarcoma

Evaluating Circulating Biomarkers for Diagnosis, Prognosis, and Tumor Monitoring in Pediatric Sarcomas: Recent Advances and Future Directions

Pediatric sarcomas present a significant challenge in oncology. There is an urgent need for improved therapeutic strategies for high-risk patients and better management of long-term side effects for those who survive the disease. Liquid biopsy is emerging as a promising tool to optimize treatment in these patients by offering non-invasive, repeatable assessments of disease status. Circulating biomarkers can provide valuable insights into tumor genetics and treatment response, potentially facilitating early diagnosis and dynamic disease monitoring. This review examines the potential of liquid biopsies, focusing on circulating biomarkers in the most common pediatric sarcomas, i.e., osteosarcoma, Ewing sarcoma, and rhabdomyosarcoma. We also highlight the current research efforts and the necessary advancements required before these technologies can be widely adopted in clinical practice.

Advancing rare cancer research by MALDI mass spectrometry imaging: Applications, challenges, and future perspectives in sarcoma

MALDI mass spectrometry imaging (MALDI imaging) uniquely advances cancer research, by measuring spatial distribution of endogenous and exogenous molecules directly from tissue sections. These molecular maps provide valuable insights into basic and translational cancer research, including tumor biology, tumor microenvironment, biomarker identification, drug treatment, and patient stratification. Despite its advantages, MALDI imaging is underutilized in studying rare cancers. Sarcomas, a group of malignant mesenchymal tumors, pose unique challenges in medical research due to their complex heterogeneity and low incidence, resulting in understudied subtypes with suboptimal management and outcomes. In this review, we explore the applicability of MALDI imaging in sarcoma research, showcasing its value in understanding this highly heterogeneous and challenging rare cancer. We summarize all MALDI imaging studies in sarcoma to date, highlight their impact on key research fields, including molecular signatures, cancer heterogeneity, and drug studies. We address specific challenges encountered when employing MALDI imaging for sarcomas, and propose solutions, such as using formalin-fixed paraffin-embedded tissues, and multiplexed experiments, and considerations for multi-site studies and digital data sharing practices. Through this review, we aim to spark collaboration between MALDI imaging researchers and clinical colleagues, to deploy the unique capabilities of MALDI imaging in the context of sarcoma.

Neoadjuvant Therapies Do Not Reduce Epidermal Growth Factor Receptor (EGFR) Expression or EGFR-Targeted Fluorescence in a Murine Model of Soft-Tissue Sarcomas

PURPOSE

ABY-029, an epidermal growth factor receptor (EGFR)-targeted, synthetic Affibody peptide labeled with a near-infrared fluorophore, is under investigation for fluorescence-guided surgery of sarcomas. To date, studies using ABY-029 have occurred in tumors naïve to chemotherapy (CTx) and radiation therapy (RTx), although these neoadjuvant therapies are frequently used for sarcoma treatment in humans. The goal of this study was to evaluate the impact of CTx and RTx on tumor EGFR expression and ABY-029 fluorescence of human soft-tissue sarcoma xenografts in a murine model.

PROCEDURES

Immunodeficient mice (n = 98) were divided into five sarcoma xenograft groups and three treatment groups - CTx only, RTx only, and CTx followed by RTx, plus controls. Four hours post-injection of ABY-029, animals were sacrificed followed by immediate fluorescence imaging of ex vivo adipose, muscle, nerve, and tumor tissues. Histological hematoxylin and eosin staining confirmed tumor type, and immunohistochemistry staining determined EGFR, cluster of differentiation 31 (CD31), and smooth muscle actin (SMA) expression levels. Correlation analysis (Pearson's correlation coefficients, r) and linear regression (unstandardized coefficient estimates, B) were used to determine statistical relationships in molecular expression and tissue fluorescence between xenografts and treatment groups.

RESULTS

Neoadjuvant therapies had no broad impact on EGFR expression (|B|≤ 7.0, p ≥ 0.4) or on mean tissue fluorescence (any tissue type, (|B|≤ 2329.0, p ≥ 0.1). Mean tumor fluorescence was significantly related to EGFR expression (r = 0.26, p = 0.01), as expected.

CONCLUSION

Results suggest that ABY-029 as an EGFR-targeted, fluorescent probe is not negatively impacted by neoadjuvant soft-tissue sarcoma therapies, although validation in humans is required.

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.

Genetic, Epigenetic and Transcriptome Alterations in Liposarcoma for Target Therapy Selection

Liposarcoma (LPS) is one of the most common adult soft-tissue sarcomas (STS), characterized by a high diversity of histopathological features as well as to a lesser extent by a spectrum of molecular abnormalities. Current targeted therapies for STS do not include a wide range of drugs and surgical resection is the mainstay of treatment for localized disease in all subtypes, while many LPS patients initially present with or ultimately progress to advanced disease that is either unresectable, metastatic or both. The understanding of the molecular characteristics of liposarcoma subtypes is becoming an important option for the detection of new potential targets and development novel, biology-driven therapies for this disease. Innovative therapies have been introduced and they are currently part of preclinical and clinical studies. In this review, we provide an analysis of the molecular genetics of liposarcoma followed by a discussion of the specific epigenetic changes in these malignancies. Then, we summarize the peculiarities of the key signaling cascades involved in the pathogenesis of the disease and possible novel therapeutic approaches based on a better understanding of subtype-specific disease biology. Although heterogeneity in liposarcoma genetics and phenotype as well as the associated development of resistance to therapy make difficult the introduction of novel therapeutic targets into the clinic, recently a number of targeted therapy drugs were proposed for LPS treatment. The most promising results were shown for CDK4/6 and MDM2 inhibitors as well as for the multi-kinase inhibitors anlotinib and sunitinib.

Utility of Retrospective Molecular Analysis in Diagnostically Challenging Mesenchymal Neoplasms

Introduction: Molecular analysis plays a growing role in the diagnosis of mesenchymal neoplasms. The aim of this study was to retrospectively apply broad, multiplex molecular assays (a solid tumor targeted next-generation sequencing [NGS]) assay and single nucleotide polymorphism [SNP] microarray) to selected tumors, exploring the current utility and limitations. Methods: We searched our database (2010-2020) for diagnostically challenging mesenchymal neoplasms. After histologic review of available slides, tissue blocks were selected for NGS, SNP microarray, or both. DNA and RNA were extracted using the AllPrep DNA/RNA FFPE Kit Protocol on the QIAcube instrument. The NGS platform used was the TruSight Tumor 170 (TST-170). For SNP array, copy number variant (CNV) analysis was performed using the OncoScanTM CNV Plus Assay. Results: DNA/RNA was successfully extracted from 50% of tumors (n = 10/20). Specimens not successfully extracted included 6 core biopsies, 3 incisional biopsies, and 1 resection; 4 were decalcified (3 hydrochloric acid, 1 ethylenediaminetetraacetic acid). Higher tumor proportion and number of tumor cells were parameters positively associated with sufficient DNA/RNA extraction whereas necrosis and decalcification were negatively associated with sufficient extraction. Molecular testing helped reach a definitive diagnosis in 50% of tumors (n = 5/10). Conclusions: Although the overall utility of this approach is limited, these molecular panels can be helpful in detecting a specific "driver" alteration.

Predictive Biomarkers of Pathological Response to Neoadjuvant Chemoradiotherapy for Locally Advanced Soft Tissue Sarcomas

BACKGROUND

Marginally resectable and unresectable soft tissue sarcomas (STS) remain a therapy challenge due to the lack of highly active treatment. The aim of the study was to identify a biomarker to predict the pathological response (PR) to preplanned treatment of these STSs.

METHODS

In the phase II clinical trial (NCT03651375), locally advanced STS patients received preoperative treatment with a combination of doxorubicin-ifosfamide chemotherapy and 5 × 5 Gy radiotherapy. PR to the treatment was classified using the European Organization for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group recommendations. We have chosen HIF-1α, CD163, CD68, CD34, CD105, and γH2AFX proteins, rendering different biological phenomena, for biomarker study.

RESULTS

Nineteen patients were enrolled and in four cases a good PR was reported. The high expression of HIF-1α before surgery showed a negative correlation with PR, which means a poor response to therapy. Furthermore, the samples after surgery had decreased expression of HIF-1α, which confirmed the correlation with PR. However, high expression of γH2AFX positively correlated with PR, which provides better PR. The high number of positive-staining TAMs and the high IMVD did not correlate with PR.

CONCLUSIONS

HIF1α and γH2AFX could be potential biomarkers for PR prediction after neoadjuvant treatment in STS.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of soft tissue tumors 2020 - Secondary publication

BACKGROUND

These clinical practice guidelines are intended to provide recommendations based on the best evidence obtained to date on key issues in clinical practice to improve the prognosis, diagnostic and therapeutic processes for patients with soft tissue tumors.

METHODS

The Guidelines Development Committee and Systematic Review Committee were composed of a multidisciplinary team of specialists who play an important role in soft tissue tumor care. Clinical questions (CQs) were determined by choosing key decision-making points based on Algorithms for the diagnosis and treatment of soft tissue tumors. The guidelines were developed according to the "Medical Information Network Distribution Service (Minds) Handbook for Clinical Practice Guideline Development 2014" and "Minds Manual for Clinical Practice Guideline Development 2017." Recommendation strength was rated on two levels and the strength of evidence was rated on four levels. The recommendations were decided based on agreement by 70% or more voters.

RESULTS

Twenty-two CQs were chosen by the Guidelines Development Committee. The Systematic Review Committee reviewed the evidence concerning each CQ, a clinical value judgment was added by experts, and the text of each recommendation was determined.

CONCLUSION

We established 22 CQs and recommendations for key decision-making points in the diagnosis and treatment of soft tissue tumors according to the Minds Clinical Practice Guideline development methods. We hope that these guidelines will assist the decision-making of all medical staff engaged in the treatment and diagnosis of soft tissue tumors, and eventually lead to improved soft tissue tumor care in the country.

Accuracy of core needle biopsy for histologic diagnosis of soft tissue sarcoma

The biopsy technique of choice in soft tissue sarcoma (STS) diagnosis is controversial. We examined the diagnostic accuracy of percutaneous core needle biopsy (CNB) and compared it to open incisional biopsy. A retrospective study included 91 incisional biopsies and 102 CNBs. A pair-match investigation was conducted on 19 patient pairs, comparing sensitivity, specificity, and diagnostic accuracy. Furthermore, we investigated the role of molecular pathology in sarcoma diagnostics. In 81/91 (89%) patients with incisional biopsy, the entity was confirmed by definitive pathology, whereas this was the case in 89/102 (87%) CNB patients (p = 0.52). Grading remained unchanged in 46/55 (84%) of incisional and 54/62 (87%) of CNBs (p = 0.61). The pair matched analysis showed that the correct entity was determined in 96% of incisional and 97.6% of core needle biopsies. The time between the initial consultation and the interdisciplinary tumor board's treatment recommendation was shorter in core needle biopsies (8.37 vs. 15.63 days; p < 0.002). Incisional biopsies led to two wound infections and one hematoma, whereas wound infection occurred in one patient after CNB. CNB leads to faster diagnosis while reaching the same histological accuracy and is less burdensome for patients. Still, surgeons need to remain aware of the possibility of biopsy failure.

Pyroptosis-Related Gene Signature Is a Novel Prognostic Biomarker for Sarcoma Patients

Sarcoma is a rare and an extremely aggressive form of cancer that originates from mesenchymal cells. Pyroptosis exerts a dual effect on tumours by inhibiting tumour cell proliferation while creating a microenvironment suitable for tumour cell development and proliferation. However, the significance of pyroptosis-related gene (PRG) expression in sarcoma has not yet been evaluated. Here, we conduct a retrospective analysis to examine PRG expression in 256 sarcoma samples from The Cancer Genome Atlas database. We identified the PRGs that had a significant correlation with overall patient survival in sarcoma by performing a univariate Cox regression analysis. Subsequently, we conducted a LASSO regression analysis and created a risk model for a six-PRG signature. As indicated from the Kaplan–Meier analysis, this signature revealed a significant difference between high- and low-risk sarcoma patients. A receiver operating characteristic curve analysis confirmed that this signature could predict overall patient survival in sarcoma patients with high sensitivity and specificity. Gene ontology annotation and Kyoto Encyclopaedia of Genes and Genomes pathway enrichment analyses revealed that five independent PRGs were closely associated with increased immune activity. Moreover, we also deciphered that increased number of immune cells infiltrated the tumour microenvironment in sarcoma. In brief, the PRG signature can effectively act as novel prognostic biomarker for sarcoma patients and is associated with the tumour immune microenvironment.

Natural speed of growth of untreated soft-tissue sarcomas: A dimension-based imaging analysis

PURPOSE

The interval from first symptoms to diagnosis, staging and referral to reference center can last months for soft-tissue sarcoma (STS) patients. Meanwhile, patients can undergo different imaging that capture the 'natural' tumor changes, before medical intervention. Aim was to depict these 'natural' dimensional variations and to correlate them with patients' outcome.

METHODS

Single-center retrospective study including all consecutive adults with newly-diagnosed STS, ≥2 pre-treatment imaging (CT-scan or MRI) on the tumor (Exam-0 and Exam-1), and managed in reference center between 2007 and 2018. Longest diameter (LD) and volume were calculated on both examinations to obtain the naïve dimensional growth before any intervention. SARCULATOR nomogram was applied on data at Exam-0 and Exam-1. Correlations with overall, metastatic and local relapse-free survivals (OS, MFS and LFS), and with pre-treatment pathological features were performed.

RESULTS

137 patients were included (median age: 65 years). Average naïve growth was +39.4% in LD and +503% in volume during an average Exam-0-to-Exam-1 interval of 130 days. The 10-year distant metastasis and OS predictions were different at Exam-0 and Exam-1 (P < 0.0001 for both). All the changes in radiological measurements significantly correlated with pre-treatment number of mitosis, grade and complex genomic (P-value range: <0.0001-0.0481). Multivariate Cox modeling identified the relative change in LD/month and absolute change in LD/month as independent predictors for OS and LFS, respectively (P = 0.0003 and 0.0001, respectively).

CONCLUSION

When available, the natural speed of growth on pre-treatment imaging should be evaluated to improve the estimation of pre-treatment histological grade and patients' OS and LFS.

Over-methylation of Histone H3 Lysines Is a Common Molecular Change Among the Three Major Types of Soft-tissue Sarcoma in Patient-derived Xenograft (PDX) Mouse Models

BACKGROUND/AIM

Sarcomas are considered a heterogeneous disease with incomplete understanding of its molecular basis. In the present study, to further understand general molecular changes in sarcoma, patient-derived xenograft (PDX) mouse models of the three most common soft-tissue sarcomas: myxofibrosarcoma, undifferentiated pleomorphic sarcoma (UPS) and liposarcoma were established and the methylation status of histone H3 lysine marks was studied.

MATERIALS AND METHODS

Immunoblotting and immunohistochemical staining were used to quantify the extent of methylation of histone H3K4me3 and histone H3K9me3.

RESULTS

In all 3 sarcoma types in PDX models, histone H3K4me3 and H3K9me3 were found highly over-methylated compared to normal muscle tissue.

CONCLUSION

Histone H3 lysine over-methylation may be a general basis of malignancy of the major sarcoma types.

Clinical biomarkers in soft tissue sarcoma A comprehensive review of current soft tissue sarcoma biomarkers

Soft tissue sarcomas (STS) are a heterogeneous group of tumors that arise from mesenchymal tissue. Investigation at the molecular level has been challenging due to the rarity of STS and the number of histologic subtypes. However, recent research has provided new insight into potential genomic, proteomic, and immunological biomarkers of STS. The identification of biomarkers can improve diagnosis, prognosis, and prediction of recurrence and treatment response. This review provides an understanding of biomarkers, discussing the current status of biomarker research in STS.

Soft Tissue Sarcoma: An Insight on Biomarkers at Molecular, Metabolic and Cellular Level

Simple Summary

Soft tissue sarcoma is a rare mesenchymal malignancy. Despite the advancements in the fields of radiology, pathology and surgery, these tumors often recur locally and/or with metastatic disease. STS is considered to be a diagnostic challenge due to the large variety of histological subtypes with clinical and histopathological characteristics which are not always distinct. One of the important clinical problems is a lack of useful biomarkers. Therefore, the discovery of biomarkers that can be used to detect tumors or predict tumor response to chemotherapy or radiotherapy could help clinicians provide more effective clinical management.

Abstract

Soft tissue sarcomas (STSs) are a heterogeneous group of rare tumors. Although constituting only 1% of all human malignancies, STSs represent the second most common type of solid tumors in children and adolescents and comprise an important group of secondary malignancies. Over 100 histologic subtypes have been characterized to date (occurring predominantly in the trunk, extremity, and retroperitoneum), and many more are being discovered due to molecular profiling. STS mortality remains high, despite adjuvant chemotherapy. New prognostic stratification markers are needed to help identify patients at risk of recurrence and possibly apply more intensive or novel treatments. Recent scientific advancements have enabled a more precise molecular characterization of sarcoma subtypes and revealed novel therapeutic targets and prognostic/predictive biomarkers. This review aims at providing a comprehensive overview of the most relevant cellular, molecular and metabolic biomarkers for STS, and highlight advances in STS-related biomarker research.

CD11c-CD8 Spatial Cross Presentation: A Novel Approach to Link Immune Surveillance and Patient Survival in Soft Tissue Sarcoma

Checkpoint inhibitors are slowly being introduced in the care of specific sarcoma subtypes such as undifferentiated pleomorphic sarcoma, alveolar soft part sarcoma, and angiosarcoma even though formal indication is lacking. Proper biomarkers to unravel potential immune reactivity in the tumor microenvironment are therefore expected to be highly warranted. In this study, intratumoral spatial cross presentation was investigated as a novel concept where immune cell composition in the tumor microenvironment was suggested to act as a proxy for immune surveillance. Double immunohistochemistry revealed a prognostic role of direct spatial interactions between CD11c+ antigen-presenting cells (APCs) and CD8+ cells in contrast to each marker alone in a soft tissue sarcoma (STS) cohort of 177 patients from the Karolinska University Hospital (MFS p = 0.048, OS p = 0.025). The survival benefit was verified in multivariable analysis (MFS p = 0.012, OS p = 0.004). Transcriptomics performed in the TCGA sarcoma cohort confirmed the prognostic value of combining CD11c with CD8 (259 patients, p = 0.005), irrespective of FOXP3 levels and in a CD274 (PD-LI)-rich tumor microenvironment. Altogether, this study presents a histopathological approach to link immune surveillance and patient survival in STS. Notably, spatial cross presentation as a prognostic marker is distinct from therapy response-predictive biomarkers such as immune checkpoint molecules of the PD-L1/PD1 pathway.

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.

Primary Intracranial Angiomatoid Fibrous Histiocytoma: Two Case Reports and Literature Review

BACKGROUND

Angiomatoid fibrous histiocytoma (AFH) is a rare, fibrohistiocytic, soft-tissue neoplasm. Intracranial AFH is extremely rare. Here we present 2 pediatric cases of intracranial AFH and perform a literature review on this disease entity.

CASE DESCRIPTION

We present 2 cases. The first case is a 10-year-old boy who presented with seizures and hemiparesis. The second case is an 11-year-old girl who presented with 2-year history of seizures. Radiologic images demonstrated right frontal lesions in both patients. Complete surgical resection was achieved. Histopathological findings established the diagnosis of intracranial AFH confirmed with fluorescence in situ hybridization and reverse transcriptase polymerase chain reaction testing that demonstrated EWSR1 gene rearrangement in both cases.

CONCLUSIONS

Twenty-two cases of intracranial AFH have been previously documented, with the majority of lesions located in the frontal lobe. Most cases occurred in adolescents and young adults, with a slight female predilection. Headaches and seizures constituted the most common clinical presentation. Complete surgical resection remains the standard of care in the management of this pathology.

The landscape of gene mutations and clinical significance of tumor mutation burden in patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy

BACKGROUND

The aim of this study was to evaluate the landscape of gene mutations and the clinical significance of tumor mutation burden (TMB) in patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy.

METHODS

A total of 68 patients with soft tissue sarcoma were included. Postoperative tumor tissue specimens from the patients were collected for DNA extraction. Targeted next-generation sequencing of cancer-relevant genes was performed for the detection of gene mutations and the analysis of TMB. Univariate analysis between TMB status and prognosis was carried out using the Kaplan-Meier survival analysis, and multivariate analysis was adjusted by the Cox regression model.

RESULTS

No specific genetic mutations associated with soft tissue sarcoma were found. The mutation frequency of TP53, PIK3C2G, NCOR1, and KRAS of the 68 patients with soft tissue sarcoma were observed in 19 cases (27.94%), 15 cases (22.06%), 14 cases (20.59%), and 14 cases (20.59%), respectively. With regard to the analysis of TMB, the overall TMB of the 68 patients with soft tissue sarcoma was relatively low (median: 2.05 per Mb (range: 0∼15.5 per Mb)). Subsequently, TMB status was divided into TMB-Low and TMB-Middle according to the median TMB. Patients with TMB-Low and TMB-Middle were 37 cases (54.41%) and 31 cases (45.59%), respectively. Overall survival analysis indicated that the median overall survival of patients with TMB-Low and TMB-Middle was not reached, and 4.5 years, respectively (P=0.015).

CONCLUSION

This study characterizes the genetic background of patients with STS soft tissue sarcoma. The TMB was of clinical significance for patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy.

A review of retroperitoneal liposarcoma genomics

Retroperitoneal liposarcomas are rare tumours that carry a poorer prognosis than their extremity counterparts. Within their subtypes - well differentiated (WDL), dedifferentiated (DDL), myxoid (MLS) and pleomorphic (PLS) - they exhibit a diverse genomic landscape. With recent advances in next generation sequencing, the number of studies exploring this have greatly increased. The recent literature has deepened our understanding of the hallmark MDM2/CDK4 amplification in WDL/DDL and addressed concerns about toxicity and resistance when targeting this. The FUS-DDIT3 fusion gene remains the primary focus of interest in MLS with additional potential targets described. Whole genome sequencing has driven identification of novel genes and pathways implicated in WDL/DDL outside of the classic 12q13-15 amplicon. Due to their rarity; anatomical location and histologic subtype are infrequently mentioned when reporting the results of these studies. Reports can include non-adipogenic or extremity tumours, making it difficult to draw specific retroperitoneal conclusions. This narrative review aims to provide a summary of retroperitoneal liposarcoma genomics and the implications for therapeutic targeting.

SP1-Induced Upregulation of lncRNA LINC00514 Promotes Tumor Proliferation and Metastasis in Osteosarcoma by Regulating miR-708

Background

Growing studies have suggested the dysregulation of long non-coding RNAs (lncRNAs) in several tumors, including osteosarcoma (OS). However, limited studies report metastasis-associated lncRNAs in OS. Our present study aimed to explore the roles of lncRNA LINC00514 (LINC00514) in OS.

Materials and Methods

The LINC00514 expression was measured using qPCR assays in OS tissues and cell lines. The clinical significance of LINC00514 expression in OS patients was analyzed using chi-square test, Kaplan–Meier assays and multivariate analysis. The possible effects of LINC00514 in tumor cellular progression were determined using a series of functional assays. The mechanisms of LINC00514 action were explored through bioinformatics, luciferase reporter assays and RT-PCR assays. The mechanisms involved the upregulation of LINC00514 expression in OS were determined using luciferase reporter and chromatin immunoprecipitation (ChIP) assays.

Results

We showed that LINC00514 expressions were distinctly upregulated in both OS tissues and cell lines, especially in advanced cases. High levels of LINC0051 were positively correlated with advanced tumor stages, distant metastasis, and reduced survival of patients with OS. Functional experiments indicated that silencing of LINC00514 suppressed the ability of cell growth, colony formation and metastasis, whereas promoted cell apoptosis in vitro. Mechanistic investigation revealed that LINC00514 could directly bind to miR-708 and effectively serve as a ceRNA for miR-708. In addition, LINC00514 was upregulated by the transcription factor SP1.

Conclusion

Our findings revealed SP1-induced upregulation of LINC00514 as an oncogene in OS through competitively binding to miR-708, suggesting that there are potential diagnostic and treatment values of LINC00514 in OS.

Antitumoral effects of [6]-gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone] in sarcoma 180 cells through cytogenetic mechanisms

BACKGROUND

[6]-Gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone] is a phenolic substance reported for several ethnopharmacological usage by virtue of its antioxidant, antiemetic, anti-inflammatory and anticancer properties. This study assessed the antitumoral effects of [6]-Gingerol in primary cells of Sarcoma 180 as well as in peripheral blood lymphocytes of mice.

METHODS

The effect of [6]-Gingerol was assessed by applying cytogenetic biomarkers as indicative of genotoxicity, mutagenicity and apoptosis. Ascitic liquid cells were treated with [6]-Gingerol at concentrations of 21.33, 42.66 and 85.33 μM and subjected to the cytotoxicity assays using Trypan blue test and the comet assay, as well as the cytokinesis-block micronucleus assay. Doxorubicin (6 μM) and hydrogen peroxide (85.33 μM) were used as positive controls.

RESULTS

[6]-Gingerol, especially at concentrations of 42.66 and 85.33 μM, showed notable cytotoxicity in Sarcoma 180 cells by reducing cell viability and cell division rates via induction of apoptosis. Genotoxicity at the concentrations used was punctuated by the increase in the index and frequency of DNA damage in tested groups. [6]-Gingerol, at all concentrations tested, did not induce significant aneugenic and/or clastogenic effects. It did, however, induced other nuclear abnormalities, such as nucleoplasmic bridges, nuclear buds and apoptosis. The genotoxic effects observed in the cotreatment with H₂O₂ (challenge assay) employing neoplastic and healthy cells, indicated that [6]-Gingerol may induce oxidative stress.

CONCLUSIONS

Observations suggest that [6]-Gingerol may be a candidate for pharmaceutical antitumoral formulations due to its cytotoxicity and to mechanisms associated with genetic instability generated by nuclear alterations especially by apoptosis.

Morphologic and immunophenotypical features distinguishing Merkel cell polyomavirus-positive and negative Merkel cell carcinoma

In 2008, Feng et al. identified Merkel cell polyomavirus integration as the primary oncogenic event in ~80% of Merkel cell carcinoma cases. The remaining virus-negative Merkel cell carcinoma cases associated with a high mutational load are most likely caused by UV radiation. The current study aimed to compare the morphological and immunohistochemical features of 80 virus-positive and 21 virus-negative Merkel cell carcinoma cases. Microscopic evaluation revealed that elongated nuclei-similar to the spindle-shape variant of small cell lung cancer-were less frequent in Merkel cell polyomavirus-positive Merkel cell carcinoma compared to the virus-negative subset (p = 0.005). Moreover, virus-negative cases more frequently displayed a "large-cell neuroendocrine carcinoma" phenotype with larger cell size (p = 0.0026), abundant cytoplasm (p = 4×10^-7) and prominent nucleoli (p = 0.002). Analysis of immunohistochemical data revealed frequent positivity for thyroid transcription factor 1 and cytokeratin 7, either absence or overexpression of p53, as well as frequent lack of neurofilament expression in virus-negative cases. By contrast, cytokeratin 8, 18 and 20 and a CD99 with a dot pattern as well as high EMA expression were identified as characteristic features of virus-positive Merkel cell carcinoma. In particular, the CD99 dot-like expression pattern was strongly associated with presence of the Merkel cell polyomavirus in Merkel cell carcinoma (sensitivity = 81%, specificity = 90%, positive likelihood ratio = 8.08). To conclude, virus-positive and -negative Merkel cell carcinoma are characterized by distinct morphological and immunohistochemical features, which implies a significant difference in tumor biology and behavior. Importantly, we identified the CD99 staining pattern as a marker indicating the virus status of this skin cancer.

Non-gastrointestinal stromal tumours soft tissue sarcomas: an update

Soft tissue sarcomas (STS) encompass a diverse family of neoplasms of mesenchymal origin, marked by significant heterogeneity in terms of physiopathology, molecular characterisation, natural history and response to different therapies. This review aims to summarise the current strategies for the management of patients with STS, including surgery, systemic treatments and radiation therapy, along with considerations applicable to the most frequent subtypes, as well as particularities associated with less common and specific histologies. It also provides insights into upcoming strategies to tackle this challenging group of diseases.

The PTEN Tumor Suppressor Gene in Soft Tissue Sarcoma

Soft tissue sarcoma (STS) is a rare malignancy of mesenchymal origin classified into more than 50 different subtypes with distinct clinical and pathologic features. Despite the poor prognosis in the majority of patients, only modest improvements in treatment strategies have been achieved, largely due to the rarity and heterogeneity of these tumors. Therefore, the discovery of new prognostic and predictive biomarkers, together with new therapeutic targets, is of enormous interest. Phosphatase and tensin homolog (PTEN) is a well-known tumor suppressor that commonly loses its function via mutation, deletion, transcriptional silencing, or protein instability, and is frequently downregulated in distinct sarcoma subtypes. The loss of PTEN function has consequent alterations in important pathways implicated in cell proliferation, survival, migration, and genomic stability. PTEN can also interact with other tumor suppressors and oncogenic signaling pathways that have important implications for the pathogenesis in certain STSs. The aim of the present review is to summarize the biological significance of PTEN in STS and its potential role in the development of new therapeutic strategies.

Intracranial Angiomatoid Fibrous Histiocytoma with EWSR1-CREB Family Fusions: A Report of 2 Pediatric Cases

BACKGROUND

Intracranial angiomatoid fibrous histiocytomas (AFHs) are very rare tumors. Histologically, classical cases have been reported exclusively in adults, with myxoid variants identified only in children. Here, we report the clinical presentation, treatment, biopsy, and molecular test results for 2 children with classical intracranial AFH and combine this with a literature review of published intracranial AFH and AFH-like cases.

CASE DESCRIPTION

Two young girls presenting with abnormal neurologic signs, received diagnoses of intracranial AFHs from histopathologic analysis. No myxoid features were identified. Fluorescence in situ hybridization and reverse transcriptase polymerase chain reaction testing demonstrated EWS1-ATF1 and EWS1-CREM gene fusions, respectively, verified by Sanger sequencing. Both patients underwent surgery only. The first child experienced local recurrence 5 years from initial surgery. Following a further complete resection, this patient has remained recurrence free over a subsequent 6-year follow-up period. The second patient has recently experienced local multinodular recurrence 28 months after initial surgery and is awaiting surgical re-excision. No additional chemotherapy/radiotherapy has been administered to either patient.

CONCLUSIONS

This report describes the first 2 cases of nonmyxoid intracranial AFH in children; confirmed by molecular analysis. Our results suggest that a tumor spectrum incorporating classical and myxoid intracranial AFHs can occur in children and that gross total resection represents the treatment strategy of choice at diagnosis or following recurrence.

Elevated circulating macrophage inhibitory cytokine 1 is a biological marker for the diagnosis and prognosis of osteosarcoma

Osteosarcoma is among the most frequently occurring bone tumors in infants and teenagers. However, despite its widespread prevalence, no effective diagnostic and prognostic biomarkers for osteosarcoma are known. Macrophage inhibitory cytokine 1 (MIC-1) has been considered a promising biological marker of various tumor types. However, the possible role of circulating MIC-1 as a screening biomarker for osteosarcoma remains to be elucidated. The present study evaluated the circulating levels of MIC-1 in patients with osteosarcoma with the aim of elucidating its effect on the diagnosis and prognosis of this specific tumor. The circulating levels of MIC-1 were measured via an enzyme-linked immunosorbent assay in 300 individuals, including 100 patients with osteosarcoma, 100 patients with benign bone tumors, and 100 healthy subjects, and its correlation with clinicopathological characteristics was then evaluated. Various analyses were performed to determine its utility in diagnosis and prognosis. The levels of circulating MIC-1 were increased considerably in patients with osteosarcoma. The patients bearing larger tumors, those with distant metastases, and those with later-stage tumors had relatively higher levels of MIC-1. According to the multivariate logistic regression analysis, a high level of circulating MIC-1 was an independent variable for distant metastases. Receiver operating characteristic analysis revealed MIC-1 as a possible biological marker for distinguishing patients from healthy controls. Patients with osteosarcoma with higher levels of MIC-1 had relatively higher risk of mortality. Furthermore, multivariate data analysis on general survival rate revealed that a high level of circulating MIC-1 was a prognostic indicator of osteosarcoma. These findings suggest that an elevated level of circulating MIC-1 is a novel potential diagnostic and prognostic biomarker for osteosarcoma.

Global Health Perspective in Sarcomas and Other Rare Cancers

Sarcomas, rare and heterogenous malignancies that comprise less than 1% of all cancers, have poor outcomes in the metastatic and refractory setting. Their management requires a multidisciplinary approach that consists of medical and surgical oncologists, radiation oncologists, and pathologists as well as ancillary support. In addition to systemic treatments, most patients will require surgical resection and radiation therapy, which mandates the use of the latest technologies and specialized expertise. Management guidelines have been developed in high-income countries, but their applicability in low-income countries, where resources may be limited, remains a challenge. In this article, we propose the best possible evidence-based practices specifically for income-constrained settings to overcome this challenge. In addition, we review the different methods that can be used in low-income countries to access new and expensive treatments, which often times carry prohibitive costs for these areas.

Sarcomas of the Oral and Maxillofacial Region: Analysis of 26 Cases with Emphasis on Diagnostic Challenges

Sarcomas of the Oral and Maxillofacial Region (SOMR) are rare lesions which pose diagnostic and management challenges. We analyzed 26 cases of SOMR with respect to clinical presentation, histopathological subtype, treatment modalities, recurrence, and treatment outcome. In our series, Osteosarcoma (OS) was the most common type of sarcoma (7 cases), followed by 5 cases of Ewing's Sarcoma (ES), 3 cases each of Chondrosarcoma (CS) and Leiomyosarcoma (LMS), 2 cases each of Malignant Peripheral Nerve Sheath Tumor (MPNST), Pleomorphic Undifferentiated Sarcoma (PUS), Myeloid Sarcoma (MS)and Rhabdomyosarcoma (RMS). Surgery was the primary treatment modality in most cases and was combined with adjuvant chemo/ radiotherapy in few cases. 24 of the 26 cases were followed up for an average period of 40.67 months. Adverse disease outcomes like recurrence were seen in 2 cases whereas death due to the disease was reported in 7 cases. In view of the diagnostic challenges faced in SOMRs, it appears practical to stress on the underlying genetic aspects of the disease process rather than histological subtyping to improve disease outcome.

Genetic testing for high-grade osteosarcoma: a guide for future tailored treatments?

INTRODUCTION

Genetic characterization of osteosarcoma has evolved during the last decade, thanks to the integrated application of conventional and new candidate-driven and genome-wide technologies. Areas covered: This review provides an overview of the state of art in genetic testing applied to osteosarcoma, with particular regard to novel candidate genetic biomarkers that can be analyzed in tumor tissue and blood samples, which might be used to predict toxicity and prognosis, detect disease relapse, and improve patients' selection criteria for tailoring treatment. Expert commentary: Genetic testing based on modern technologies is expected to indicate new osteosarcoma-related prognostic markers and driver genes, which may highlight novel therapeutic targets and patients stratification biomarkers. The definition of tailored or targeted treatment approaches may improve outcome of patients with localized tumors and, even more, of those with metastatic disease, for whom progress in cure probability is highly warranted.

Contemporary Sarcoma Diagnosis, Genetics, and Genomics

Sarcomas include diverse mesenchymal neoplasms with widely varied prognosis, clinical behavior, and treatment. Owing to their rarity and histologic overlap, accurate diagnosis of sarcomas can be challenging. Our approach has evolved dramatically in the past few decades, where novel insights into the molecular pathogenetic basis for sarcomas has dramatically (re)shaped contemporary diagnosis, building on a largely morphology- and clinical presentation–based strategy. Examples include the introduction of novel immunohistochemical markers that serve as surrogates for molecular genetic alterations and identification of characteristic molecular alterations. Accordingly, cytogenetic and molecular genetic analyses, such as conventional karyotyping, fluorescence in situ hybridization, reverse transcription–polymerase chain reaction, and targeted sequencing, have increasingly been incorporated into the routine diagnostic work-up of these neoplasms. For those sarcomas with complex cytogenetic changes that lack specific alterations, additional testing is often directed toward identifying lines of differentiation and excluding pathognomonic (cyto-)genetic alterations. Although some gene rearrangements are diagnostic of particular sarcoma types, certain fusion partners, most notably EWSR1, are not tumor specific (and may, in fact, also be found in benign tumors). Correlation with clinical, radiologic, morphologic, and immunohistochemical findings is particularly important in tumors with such rearrangements to establish the correct diagnosis, acknowledging the inherent limitations of diagnostic tests. The recognition of sarcomas occurring in cancer predisposition syndromes is critical, with implications not only for the index patient but also potentially for family members, including the need for genetic counseling and sometimes particular types of surveillance. Together, contemporary sarcoma evaluation involves combining the initial morphologic evaluation with diagnostically relevant cytogenetic, molecular, and immunohistochemical testing methods.

Involvement of c-Fos in cell proliferation, migration, and invasion in osteosarcoma cells accompanied by altered expression of Wnt2 and Fzd9

Osteosarcoma (OS) is an aggressive bone tumor, and proto-oncogene c-Fos is involved in this lethal disease. However, the role and molecular mechanism of c-Fos in the development and progression of OS remain enigmatic. As one of the Wnt family members, Wnt2 is closely associated with the development of several malignant tumors. In the present study, the expression of c-Fos, Wnt2, and its receptor Fzd9 in human OS tissues, MG63 OS cell line, and human osteoblast hFOB 1.19 cell line was detected by Western blot analysis, immunohistochemical staining, or reverse transcription-polymerase chain reaction. The role of c-Fos in the OS was clarified by treating MG63 cells with small interfering RNA to knockdown c-Fos. Then, cell migration and invasion were assayed by transwell assays and wound healing assay; cell proliferation was assayed by MTS method and 5-ethynyl-2'-deoxyuridine DNA proliferation in vitro detection; cell apoptosis was assayed by flow cytometric method. Co-immunoprecipitation kit was used to confirm the relationship between c-Fos and Wnt2/Fzd9. We found that the expression of c-Fos, Wnt2, and Fzd9 protein was distinctly higher in human OS tissues than that in the adjacent non-cancerous tissues, and their expression in the MG63 OS cell line was markedly increased compared with that in the human osteoblast hFOB 1.19 cell line. Knockdown of c-Fos inhibited the proliferation, migration, and invasion of MG63 cells, and promoted the apoptosis of MG63 cells. Moreover, knockdown of c-Fos inhibited the expression of Wnt2 and Fzd9 mRNA and protein. Our data enforced the evidence that knockdown of c-Fos inhibited cell proliferation, migration, and invasion, and promoted the apoptosis of OS cells accompanied by altered expression of Wnt2 and Fzd9. These findings offer new clues for OS development and progression, and c-Fos may be a potential therapeutic target for OS.

Potentials of Long Noncoding RNAs (LncRNAs) in Sarcoma: From Biomarkers to Therapeutic Targets

Sarcoma includes some of the most heterogeneous tumors, which make the diagnosis, prognosis and treatment of these rare yet diverse neoplasms especially challenging. Long noncoding RNAs (lncRNAs) are important regulators of cancer initiation and progression, which implies their potential as neoteric prognostic and diagnostic markers in cancer, including sarcoma. A relationship between lncRNAs and sarcoma pathogenesis and progression is emerging. Recent studies demonstrate that lncRNAs influence sarcoma cell proliferation, metastasis, and drug resistance. Additionally, lncRNA expression profiles are predictive of sarcoma prognosis. In this review, we summarize contemporary advances in the research of lncRNA biogenesis and functions in sarcoma. We also highlight the potential for lncRNAs to become innovative diagnostic and prognostic biomarkers as well as therapeutic targets in sarcoma.