Rhabdomyosarcoma

The Capacity of Drug-Metabolising Enzymes in Modulating the Therapeutic Efficacy of Drugs to Treat Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a rare soft tissue sarcoma (STS) that predominantly affects children and teenagers. It is the most common STS in children (40%) and accounts for 5-8% of total childhood malignancies. Apart from surgery and radiotherapy in eligible patients, standard chemotherapy is the only therapeutic option clinically available for RMS patients. While survival rates for this childhood cancer have considerably improved over the last few decades for low-risk and intermediate-risk cases, the mortality rate remains exceptionally high in high-risk RMS patients with recurrent and/or metastatic disease. The intensification of chemotherapeutic protocols in advanced-stage RMS has historically induced aggravated toxicity with only very modest therapeutic gain. In this review, we critically analyse what has been achieved so far in RMS therapy and provide insight into how a diverse group of drug-metabolising enzymes (DMEs) possess the capacity to modify the clinical efficacy of chemotherapy. We provide suggestions for new therapeutic strategies that exploit the presence of DMEs for prodrug activation, targeted chemotherapy that does not rely on DMEs, and RMS-molecular-subtype-targeted therapies that have the potential to enter clinical evaluation.

Transforming Growth Factor Beta and Alveolar Rhabdomyosarcoma: A Challenge of Tumor Differentiation and Chemotherapy Response

Alveolar rhabdomyosarcoma (ARMS), an invasive subtype of rhabdomyosarcoma (RMS), is associated with chromosomal translocation events resulting in one of two oncogenic fusion genes, PAX3-FOXO1 or PAX7-FOXO1. ARMS patients exhibit an overexpression of the pleiotropic cytokine transforming growth factor beta (TGF-β). This overexpression of TGF-β1 causes an increased expression of a downstream transcription factor called SNAIL, which promotes epithelial to mesenchymal transition (EMT). Overexpression of TGF-β also inhibits myogenic differentiation, making ARMS patients highly resistant to chemotherapy. In this review, we first describe different types of RMS and then focus on ARMS and the impact of TGF-β in this tumor type. We next highlight current chemotherapy strategies, including a combination of the FDA-approved drugs vincristine, actinomycin D, and cyclophosphamide (VAC); cabozantinib; bortezomib; vinorelbine; AZD 1775; and cisplatin. Lastly, we discuss chemotherapy agents that target the differentiation of tumor cells in ARMS, which include all-trans retinoic acid (ATRA) and 5-Azacytidine. Improving our understanding of the role of signaling pathways, such as TGF-β1, in the development of ARMS tumor cells differentiation will help inform more tailored drug administration in the future.

Soft Tissue Sarcomas in Adolescents and Young Adults

Soft tissue sarcomas (STS) represent a heterogeneous group of extraskeletal mesenchymal tumors that affect individuals throughout the entire age continuum. Despite this pervasive influence, key differences exist in the presentation of these sarcomas across varying age groups that have prevented a more uniform approach to management. Notably, rhabdomyosarcoma (RMS) is more common in children, while most nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) subtypes are more prevalent in adults. Older patients with NRSTS appear to have more molecularly complex biology and often present with more advanced disease compared with children. Poorer outcome disparities are observed in older patients with RMS despite receiving similar treatment as younger patients. In this review, we highlight differences in epidemiology, biology, and management paradigms for pediatric and adult patients with STS and explore opportunities for a unified approach to enhance the care and outcomes within the AYA population.

Muscle stem cell dysfunction in rhabdomyosarcoma and muscular dystrophy

Muscle stem cells (MuSCs) are crucial to the repair and homeostasis of mature skeletal muscle. MuSC dysfunction and dysregulation of the myogenic program can contribute to the development of pathology ranging from cancers like rhabdomyosarcoma (RMS) or muscle degenerative diseases such as Duchenne muscular dystrophy (DMD). Both diseases exhibit dysregulation at nearly all steps of myogenesis. For instance, MuSC self-renewal processes are altered. In RMS, this leads to the creation of tumor propagating cells. In DMD, impaired asymmetric stem cell division creates a bias towards producing self-renewing stem cells instead of committing to differentiation. Hyperproliferation of these cells contribute to tumorigenesis in RMS and symmetric expansion of the self-renewing MuSC population in DMD. Both diseases also exhibit a repression of factors involved in terminal differentiation, halting RMS cells in the proliferative stage and thus driving tumor growth. Conversely, the MuSCs in DMD exhibit impaired differentiation and fuse prematurely, affecting myonuclei maturation and the integrity of the dystrophic muscle fiber. Finally, both disease states cause alterations to the MuSC niche. Various elements of the niche such as inflammatory and migratory signaling that impact MuSC behavior are dysregulated. Here we show how these seemingly distantly related diseases indeed have similarities in MuSC dysfunction, underlying the importance of considering MuSCs when studying the pathophysiology of muscle diseases.

Extending deterministic transport capabilities for very-high and ultra-high energy electron beams

Focused Very-High Energy Electron (VHEE, 50-300 MeV) and Ultra-High Energy Electron (UHEE, > 300 MeV) beams can accurately target both large and deeply seated human tumors with high sparing properties, while avoiding the spatial requirements and cost of proton and heavy ion facilities. Advanced testing phases are underway at the CLEAR facilities at CERN (Switzerland), NLCTA at Stanford (USA), and SPARC at INFN (Italy), aiming to accelerate the transition to clinical application. Currently, Monte Carlo (MC) transport is the sole paradigm supporting preclinical trials and imminent clinical deployment. In this paper, we propose an alternative: the first extension of the nuclear-reactor deterministic chain NJOY-DRAGON for VHEE and UHEE applications. We have extended the Boltzmann-Fokker-Planck (BFP) multigroup formalism and validated it using standard radio-oncology benchmarks, complex assemblies with a wide range of atomic numbers, and comprehensive irradiation of the entire periodic table. We report that [Formula: see text] of water voxels exhibit a BFP-MC deviation below [Formula: see text] for electron energies under [Formula: see text]. Additionally, we demonstrate that at least [Formula: see text] of voxels of bone, lung, adipose tissue, muscle, soft tissue, tumor, steel, and aluminum meet the same criterion between [Formula: see text] and [Formula: see text]. For water, the thorax, and the breast intra-operative benchmark, typical average BFP-MC deviations of [Formula: see text] and [Formula: see text] were observed at [Formula: see text] and [Formula: see text], respectively. By irradiating the entire periodic table, we observed similar performance between lithium ([Formula: see text]) and cerium ([Formula: see text]). Deficiencies observed between praseodymium ([Formula: see text]) and einsteinium ([Formula: see text]) have been reported, analyzed, and quantified, offering critical insights for the ongoing development of the Evaluated Nuclear Data File mode in NJOY.

BRD4 isoforms have distinct roles in tumour progression and metastasis in rhabdomyosarcoma

BRD4, a bromodomain and extraterminal (BET) protein, is deregulated in multiple cancers and has emerged as a promising drug target. However, the function of the two main BRD4 isoforms (BRD4-L and BRD4-S) has not been analysed in parallel in most cancers. This complicates determining therapeutic efficacy of pan-BET inhibitors. In this study, using functional and transcriptomic analysis, we show that BRD-L and BRD4-S isoforms play distinct roles in fusion negative embryonal rhabdomyosarcoma. BRD4-L has an oncogenic role and inhibits myogenic differentiation, at least in part, by activating myostatin expression. Depletion of BRD4-L in vivo impairs tumour progression but does not impact metastasis. On the other hand, depletion of BRD4-S has no significant impact on tumour growth, but strikingly promotes metastasis in vivo. Interestingly, BRD4-S loss results in the enrichment of BRD4-L and RNA Polymerase II at integrin gene promoters resulting in their activation. In fusion positive alveolar rhabdomyosarcoma, BRD4-L is unrestricted in its oncogenic role, with no evident involvement of BRD4-S. Our work unveils isoform-specific functions of BRD4 in rhabdomyosarcoma.

Magnesium-ibogaine therapy in veterans with traumatic brain injuries

Traumatic brain injury (TBI) is a leading cause of disability. Sequelae can include functional impairments and psychiatric syndromes such as post-traumatic stress disorder (PTSD), depression and anxiety. Special Operations Forces (SOF) veterans (SOVs) may be at an elevated risk for these complications, leading some to seek underexplored treatment alternatives such as the oneirogen ibogaine, a plant-derived compound known to interact with multiple neurotransmitter systems that has been studied primarily as a treatment for substance use disorders. Ibogaine has been associated with instances of fatal cardiac arrhythmia, but coadministration of magnesium may mitigate this concern. In the present study, we report a prospective observational study of the Magnesium-Ibogaine: the Stanford Traumatic Injury to the CNS protocol (MISTIC), provided together with complementary treatment modalities, in 30 male SOVs with predominantly mild TBI. We assessed changes in the World Health Organization Disability Assessment Schedule from baseline to immediately (primary outcome) and 1 month (secondary outcome) after treatment. Additional secondary outcomes included changes in PTSD (Clinician-Administered PTSD Scale for DSM-5), depression (Montgomery-Åsberg Depression Rating Scale) and anxiety (Hamilton Anxiety Rating Scale). MISTIC resulted in significant improvements in functioning both immediately (Pcorrected < 0.001, Cohen's d = 0.74) and 1 month (Pcorrected < 0.001, d = 2.20) after treatment and in PTSD (Pcorrected < 0.001, d = 2.54), depression (Pcorrected < 0.001, d = 2.80) and anxiety (Pcorrected < 0.001, d = 2.13) at 1 month after treatment. There were no unexpected or serious adverse events. Controlled clinical trials to assess safety and efficacy are needed to validate these initial open-label findings. ClinicalTrials.gov registration: NCT04313712 .

Leveraging spatial omics for the development of precision sarcoma treatments

Sarcomas are rare and heterogeneous cancers that arise from bone or soft tissue, and are the second most prevalent solid cancer in children and adolescents. Owing to the complex nature of pediatric sarcomas, the development of therapeutics for pediatric sarcoma has seen little progress in the past decades. Existing treatments are largely limited to chemotherapy, radiation, and surgery. Limited knowledge of the sarcoma tumor microenvironment (TME) and of well-defined target antigens in the different subtypes necessitates an alternative investigative approach to improve treatments. Recent advances in spatial omics technologies have enabled a more comprehensive study of the TME in multiple cancers. In this opinion article we discuss advances in our understanding of the TME of some cancers enabled by spatial omics technologies, and we explore how these technologies might advance the development of precision treatments for sarcoma, especially pediatric sarcoma.

Impact of Consolidative Radiation on Overall and Progression-Free Survival in Pediatric, Adolescent, and Young Adult Metastatic Bone and Soft Tissue Sarcoma

PURPOSE

To determine the association between consolidative radiation (RT) and survival in children, adolescents, and young adults with metastatic sarcoma.

METHODS AND MATERIALS

Eligibility criteria included patients aged ≤39 years with newly diagnosed metastatic bone or soft tissue sarcoma who completed local control of the primary tumor without disease progression. Consolidative RT was defined as RT to all known sites of metastatic disease. The Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS). The least absolute shrinkage and selection operator Cox provided adjusted estimates. To account for immortal time bias, consolidative RT was used as a time-varying covariate in a time dependent Cox model. Distant failure was estimated using the Fine-Gray model.

RESULTS

Patients (n = 85) had a median age at diagnosis of 14.8 years. Most common histology was Ewing Sarcoma (45.9%) followed by rhabdomyosarcoma (40.0%). Receipt of consolidative RT was associated with Ewing Sarcoma (P < .001) and local control modality as those who underwent local control with surgery and RT compared with surgery alone were more likely to be treated with consolidative RT (P = .034). Consolidative RT was independently associated with improved OS (hazard ratio [HR], 0.41; 95% CI, 0.17-0.98; P = .045) and improved PFS (HR, 0.37; 95% CI, 0.16-0.88; P = .024) after adjusting for confounding variables and immortal time bias. Patients treated with consolidative RT also experienced a lower risk of distant failure (HR, 0.33; 95% CI, 0.17-0.64; P = .001). In an independent data set of patients with metachronous progression (n = 36), consolidative RT remained independently associated with improved OS.

CONCLUSIONS

Consolidative RT was independently associated with improved OS and PFS and decreased risk of distant failure in child, adolescent, and young adult patients with metastatic sarcoma. Future work should evaluate biomarkers to optimize patient selection, timing, and dose for consolidative RT.

Cytoskeleton remodeling induced by SMYD2 methyltransferase drives breast cancer metastasis

Malignant forms of breast cancer refractory to existing therapies remain a major unmet health issue, primarily due to metastatic spread. A better understanding of the mechanisms at play will provide better insights for alternative treatments to prevent breast cancer cell dispersion. Here, we identify the lysine methyltransferase SMYD2 as a clinically actionable master regulator of breast cancer metastasis. While SMYD2 is overexpressed in aggressive breast cancers, we notice that it is not required for primary tumor growth. However, mammary-epithelium specific SMYD2 ablation increases mouse overall survival by blocking the primary tumor cell ability to metastasize. Mechanistically, we identify BCAR3 as a genuine physiological substrate of SMYD2 in breast cancer cells. BCAR3 monomethylated at lysine K334 (K334me1) is recognized by a novel methyl-binding domain present in FMNLs proteins. These actin cytoskeleton regulators are recruited at the cell edges by the SMYD2 methylation signaling and modulate lamellipodia properties. Breast cancer cells with impaired BCAR3 methylation lose migration and invasiveness capacity in vitro and are ineffective in promoting metastases in vivo. Remarkably, SMYD2 pharmacologic inhibition efficiently impairs the metastatic spread of breast cancer cells, PDX and aggressive mammary tumors from genetically engineered mice. This study provides a rationale for innovative therapeutic prevention of malignant breast cancer metastatic progression by targeting the SMYD2-BCAR3-FMNL axis.

When the second comes first- rhabdomyosarcoma preceding heritable retinoblastoma- a case report

BACKGROUND

Retinoblastoma (rb) is the most frequent intraocular tumor, accounting for 3% of all childhood cancers. Heritable rb survivors are germline carriers for an RB1 mutation and have a lifelong risk to develop non-ocular second primary tumors (SPTs) involving multiple other organs like the bones, soft tissues, or skin. These SPTs usually become manifest several years succeeding the diagnosis of rb. In our instance, however, a non-ocular SPT presented prior to the diagnosis of heritable rb.

CASE PRESENTATION

We report a rare case of a monozygotic twin who presented with primary rhabdomyosarcoma (RMS) preceding the manifestation of heritable rb. The rb was diagnosed when the child developed strabismus while already on therapy for the RMS. The child underwent therapy for both as per defined treatment protocols. The rb regressed well on treatment, but the RMS relapsed and the child developed multiple refractory metastatic foci and succumbed to his disease.

CONCLUSIONS

Non-ocular SPTs like sarcomas are usually known to manifest in heritable rb survivors with a lag of two to three decades (earlier if exposure to radiation is present) from the presentation of the rb. However, in our case, this seemed to be reversed with the RMS being manifest at an unusual early age and the rb being diagnosed at a later point in time.

Vaccination protects against acute respiratory distress syndrome (ARDS) in hospitalized patients with COVID-19

This study aimed to analyze the effect of COVID-19 vaccination on the occurrence of ARDS in hospitalized COVID-19 patients. The study population of this retrospective, single-center cohort study consisted of hospitalized COVID-19 patients with known vaccination status and chest computed tomography imaging between July 2021 and February 2022. The impact of vaccination on ARDS in COVID-19 patients was assessed through logistic regression adjusting for demographic differences and confounding factors with statistical differences determined using confidence intervals and effect sizes. A total of 167 patients (69% male, average age 58 years, 95% CI [55; 60], 42% fully vaccinated) were included in the data analysis. Vaccinated COVID-19 patients had a reduced relative risk (RR) of developing ARDS (RR: 0.40, 95% CI [0.21; 0.62]). Consequently, non-vaccinated hospitalized patients had a 2.5-fold higher probability of developing ARDS. This risk reduction persisted after adjusting for several confounding variables (RR: 0.64, 95% CI [0.29; 0.94]) in multivariate analysis. The protective effect of COVID-19 vaccination increased with ARDS severity (RR: 0.61, 95% CI [0.37; 0.92]). Particularly, patients under 60 years old were at risk for ARDS onset and seemed to benefit from COVID-19 vaccination (RR: 0.51, 95% CI [0.20; 0.90]). COVID-19 vaccination showed to reduce the risk of ARDS occurrence in hospitalized COVID-19 patients, with a particularly strong effect in patients under 60 years old and those with more severe ARDS.

CD73 contributes to the pathogenesis of fusion-negative rhabdomyosarcoma through the purinergic signaling pathway

Rhabdomyosarcoma (RMS) is the most common type of soft tissue sarcoma in children and adolescents. Fusion-negative RMS (FN-RMS) accounts for more than 80% of all RMS cases. The long-term event-free survival rate for patients with high-grade FN-RMS is below 30%, highlighting the need for improved therapeutic strategies. CD73 is a 5' ectonucleotidase that hydrolyzes AMP to adenosine and regulates the purinergic signaling pathway. We found that CD73 is elevated in FN-RMS tumors that express high levels of TWIST2. While high expression of CD73 contributes to the pathogenesis of multiple cancers, its role in FN-RMS has not been investigated. We found that CD73 knockdown decreased FN-RMS cell growth while up-regulating the myogenic differentiation program. Moreover, mutation of the catalytic residues of CD73 rendered the protein enzymatically inactive and abolished its ability to stimulate FN-RMS growth. Overexpression of wildtype CD73, but not the catalytically inactive mutant, in CD73 knockdown FN-RMS cells restored their growth capacity. Likewise, treatment with an adenosine receptor A2A-B agonist partially rescued FN-RMS cell proliferation and bypassed the CD73 knockdown defective growth phenotype. These results demonstrate that the catalytic activity of CD73 contributes to the pathogenic growth of FN-RMS through the activation of the purinergic signaling pathway. Therefore, targeting CD73 and the purinergic signaling pathway represents a potential therapeutic approach for FN-RMS patients.

Oral rhabdomyosarcoma, a rare malignant tumor mimicking an endodontic-periodontal lesion in an adult patient: a case report

BACKGROUND

According to previous research, 2.8% of lesions clinically identified as endodontic pathosis were ultimately diagnosed as non-endodontic periapical lesions via histopathology, and 3.7% of these non-endodontic periapical lesions were malignant neoplasms. Rhabdomyosarcoma, a malignant tumor most commonly observed in children, is uncommon in the oral cavity.

CASE PRESENTATION

This is a report of a rare case of embryonal rhabdomyosarcoma in a 41-year-old female, in which the lesion was in the maxillary gingiva. The biopsy reports confirmed the diagnosis of embryonal rhabdomyosarcoma. The wide excision of the tumor, free flap reconstruction, chemotherapy, and radiotherapy were performed. Clinical, radiological, and histopathological and management aspects of the neoplasm were also discussed.

CONCLUSIONS

This case report aimed to create awareness that rhabdomyosarcoma is one of the differential diagnoses of periapical lesions.

Non-calcified plaque in asymptomatic patients with zero coronary artery calcium score: A systematic review and meta-analysis

BACKGROUND

There is growing interest in understanding the coronary atherosclerotic burden in asymptomatic patients with zero coronary artery calcium score (CACS). In this population, we aimed to investigate the prevalence and severity of non-calcified coronary plaques (NCP) as detected by coronary CT angiography (CCTA), and to analyze the associated clinical predictors.

METHODS

This was a systematic review with meta-analysis of studies indexed in PubMed/Medline and Web of Science from inception of the database to March 31st, 2023. Using the random-effects model, separate Forest and Galbraith plots were generated for each effect size assessed. Heterogeneity was assessed using the I2 statistics whilst Funnel plots and Egger's test were used to assess for publication bias.

RESULTS

From a total of 14 studies comprising 37808 patients, we approximated the pooled summary estimates for the overall prevalence of NCP to be 10% (95%CI: 6%-13%). Similarly, the pooled prevalence of obstructive NCP was estimated at 1.1% (95%CI: 0.7%-1.5%) from a total of 10 studies involving 21531 patients. Hypertension [OR: 1.46 (95%CI:1.31-1.62)] and diabetes mellitus [OR: 1.69 (95%CI: 1.41-1.97)] were significantly associated with developing any NCP, with male gender being the strongest predictor [OR: 3.22 (95%CI: 2.17-4.27)].

CONCLUSION

There is a low burden of NCP among asymptomatic subjects with zero CACS. In a subset of this population who have clinical predictors of NCP, the addition of CCTA has a potential to provide a better insight about occult coronary atherosclerosis, however, a risk-benefit approach must be factored in prior to CCTA use given the low prevalence of NCP.

Cognitive Benefits of Sodium-Glucose Co-Transporters-2 Inhibitors in the Diabetic Milieu

Patients with diabetes are at higher risk of cognitive impairment and memory loss than the normal population. Thus, using hypoglycemic agents to improve brain function is important for diabetic patients. Sodium-glucose cotransporters-2 inhibitors (SGLT2i) are a class of therapeutic agents used in the management of diabetes that has some pharmacologic effects enabling them to fight against the onset and progress of memory deficits. Although the exact mediating pathways are not well understood, emerging evidence suggests that SGLT2 inhibition is associated with improved brain function. This study reviewed the possible mechanisms and provided evidence suggesting SGLT2 inhibitors could ameliorate cognitive deficits.

A Comprehensive Review on the Significance of Cysteine in Various Metabolic Disorders; Particularly CVD, Diabetes, Renal Dysfunction, and Ischemic Stroke

Metabolic disorders have long been a challenge for medical professionals and are a leading cause of mortality in adults. Diabetes, cardiovascular disorders (CVD), renal dysfunction, and ischemic stroke are the most prevalent ailments contributing to a high mortality rate worldwide. Reactive oxygen species are one of the leading factors that act as a fundamental root cause of metabolic syndrome. All of these disorders have their respective treatments, which, to some degree, sabotage the pathological worsening of the disease and an inevitable death. However, they pose a perilous health hazard to humankind. Cysteine, a functional amino acid shows promise for the prevention and treatment of metabolic disorders, such as CVD, Diabetes mellitus, renal dysfunction, and ischemic stroke. In this review, we explored whether cysteine can eradicate reactive oxygen species and subsequently prevent and treat these diseases.

Wide-Excision Choice in Orbital Rhabdomyosarcoma on an 8-Year-Old Patient in a Low-Resource Setting: A Case Report

Introduction

Rhabdomyosarcoma is the most common neoplasm of skeletal myoblast-like cells in children aged 5-8 years. It typically occurs in the head, neck region, genitourinary tract, retroperitoneum, and extremities.

Case Presentation

An 8-year-old boy complained of a lump under his left eye that he had felt for the past 4 years. Initially small, it gradually grew larger although there were no accompanying symptoms of redness, pain, itching, or eye movement disorders, and no history of trauma. Visual acuity in the left eye was measured at 6/15, with pinhole correction improving to 6/6, while the right eye was 6/6. Intraocular pressure in both eyes was 15 mm Hg. Anterior segment examination of the left eye revealed a mass on the lower eyelid with hard consistency, no erythema, no tenderness, with a flat surface, immobility, and all aspects of the conjunctiva, cornea, pupil, and lens appearing normal. A contrast computed tomography scan showed a solid mass measuring 2.1 × 1.9 × 1.9 cm, suggesting a left inferior eyelid mass. The patient underwent surgical excision of the tumor under general anesthesia. Histopathological examination confirmed the diagnosis of embryonal rhabdomyosarcoma. The patient was scheduled for chemotherapy.

Conclusions

Orbital rhabdomyosarcoma typically presents with sudden onset and rapid proptosis, without a history of trauma or respiratory tract infections. The embryonal subtype is the most common and has a better prognosis with combined therapy including surgery, chemotherapy, and radiation. In low-resource settings, early clinical suspicion and thorough physical examination are vital, as limited access to medical tools can complicate management. Treatment should be adapted based on available resources, and regular follow-up is essential to monitor outcomes and ensure optimal care. Any swelling in children should be carefully examined for early detection and effective intervention.

Therapeutic Potential of Quercetin in Diabetic Neuropathy and Retinopathy: Exploring Molecular Mechanisms

Diabetes mellitus poses a significant health challenge globally, often leading to debilitating complications, such as neuropathy and retinopathy. Quercetin, a flavonoid prevalent in fruits and vegetables, has demonstrated potential therapeutic effects in these conditions due to its antioxidant, anti-inflammatory, and neuroprotective properties. This review summarizes and provides a comprehensive understanding of the molecular mechanisms underlying the efficacy of quercetin in ameliorating diabetic neuropathy and retinopathy. A thorough search was carried out across scientific databases, such as SciFinder, PubMed, and Google Scholar, to gather pertinent literature regarding the effect of quercetin on diabetic neuropathy and retinopathy till February 2024. Preclinical studies indicate that quercetin mitigates neuropathic pain, sensory deficits, and nerve damage associated with diabetic neuropathy by improving neuronal function, reducing DNA damage, regulating pro-inflammatory cytokines, enhancing antioxidant enzyme levels and endothelial function, as well as restoring nerve injuries. In diabetic retinopathy, quercetin shows the potential to preserve retinal structure and function, inhibiting neovascularization, preventing retinal cell death, reducing pro-inflammatory cytokines, and increasing neurotrophic factor levels. Moreover, through modulating key signaling pathways, such as AMP-activated Protein Kinase (AMPK) activation, Glucose Transporter 4 (GLUT 4) upregulation, and insulin secretion regulation, quercetin demonstrates efficacy in reducing oxidative stress and inflammation, thereby protecting nerve and retinal tissues. Despite promising preclinical findings, challenges, such as limited bioavailability, necessitate further research to optimize quercetin's clinical application in order to establish its optimal dosage, formulation, and long-term efficacy in clinical settings.

[Characteristics of the cytogenetic variants of alveolar rhabdomyosarcoma]

Rhabdomyosarcomas (RMS) are one of the most common types of sarcomas in children and adolescents. The alveolar RMS subgroup is of particular interest because in some cases, the translocation of the PAX3 and FOXO1 genes is combined with an amplification of the corresponding hybrid gene. According to literature data, the frequency of the PAX3::FOXO1 translocation is 70-90% and the PAX7::FOXO1 translocation 10-30%.

OBJECTIVE

To determine the frequency of variable FOXO1 translocations in the alveolar RMS patient group.

MATERIAL AND METHODS

Thirty-two tumor samples were collected and analyzed using a combination of histological, immunohistochemistry (Myogenin, MyoD1), and molecular genetic techniques (fluorescence in situ hybridization (FISH) and real-time polymerase chain reaction (RT-PCR)).

RESULTS

Cytogenetic analysis using the FISH technique with a FOXO1-specific probe identified 26 (81%) samples with rearrangements at the FOXO1 locus and seven (19%) without rearrangements. Real-time PCR identified the translocation partners PAX3 in 58% (15/26) and PAX7 in 42% (11/26) of samples.

CONCLUSION

Four cytogenetic patterns were observed: classical translocation, translocation with amplification, translocation with deletion, and normal signal distribution. Alveolar rhabdomyosarcomas exhibit genetic heterogeneity and a diversity of cytogenetic profiles. The frequency ratio of PAX3/PAX7::FOXO1 variable transcripts is 1:1. Approximately 20% of cases of alveolar RMS do not have cytogenetic signs of rearrangements of the FOXO1 gene.

Glucosylated Hybrid TiO2 /Polymer Nanomaterials for Actively Targeted Sonodynamic Therapy of Cancer

Sonodynamic therapy (SDT) is an anti-cancer therapeutic strategy based on the generation of reactive oxygen species (ROS) upon local ultrasound (US) irradiation of sono-responsive molecules or nanomaterials that accumulate in the tumor. In this work, the sonodynamic efficiency of sono-responsive hybrid nanomaterials composed of amorphous titanium dioxide and an amphiphilic poly(ethylene oxide)-b-poly(propylene oxide) block copolymer is synthesized, fully characterized, and investigated both in vitro and in vivo. The modular and versatile synthetic pathway enables the control of the nanoparticle size between 30 and 300 nm (dynamic light scattering) and glucosylation of the surface for active targeting of tumors overexpressing glucose transporters. Studies on 2D and 3D rhabdomyosarcoma cell cultures reveal a statistically significant increase in the sonodynamic efficiency of glucosylated hybrid nanoparticles with respect to unmodified ones. Using a xenograft rhabdomyosarcoma murine model, it is demonstrated that by tuning the nanoparticle size and surface features, the tumor accumulation is increased by ten times compared to main off-target clearance organs such as the liver. Finally, the SDT of rhabdomyosarcoma-bearing mice is investigated with 50-nm glucosylated nanoparticles. Findings evidence a dramatic prolongation of the animal survival and tumor volumes 100 times smaller than those treated only with ultrasound or nanoparticles.

18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography and 68Ga-prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography Imaging in the Evaluation of Rare Entity Adult Embryonal Rhabdomyosarcoma of Prostate

A 21-year-old male with embryonal rhabdomyosarcoma of the prostate was referred for 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and 68Ga-prostate-specific membrane antigen (PSMA) PET/CT for initial disease staging. The PET scans revealed hypermetabolic and PSMA expressing lobulated mass involving both lobes of the prostate and weakly metabolic and PSMA expressing few bilateral pararectal and external iliac nodes, multiple bilateral lung nodules scattered over the lung parenchyma and multiple bone marrow lesions in both axial and appendicular skeleton. Magnetic resonance imaging prostate showed gross prostatomegaly with large lobulated T2 hyperintense heterogeneously enhancing mass lesion showing restricted diffusion, involving both lobes of the prostate with extraprostatic spread along anterior, posterior, and left lateral margins with evidence of lymph nodal and osseous metastases. The demonstration of increased uptake of 18F-FDG and 68Ga-PSMA in the primary as well as bilateral pararectal and external iliac nodes, multiple bilateral lung nodules, and multiple bone marrow lesions in both axial and appendicular skeleton indicates a potential role of 18F-FDG PET/CT and 68Ga-PSMA PET/CT in disease staging in this rare aggressive tumor of the prostate.

Fusion-negative rhabdomyosarcoma 3D organoids to predict effective drug combinations: A proof-of-concept on cell death inducers

Rhabdomyosarcoma (RMS) is the main form of pediatric soft-tissue sarcoma. Its cure rate has not notably improved in the last 20 years following relapse, and the lack of reliable preclinical models has hampered the design of new therapies. This is particularly true for highly heterogeneous fusion-negative RMS (FNRMS). Although methods have been proposed to establish FNRMS organoids, their efficiency remains limited to date, both in terms of derivation rate and ability to accurately mimic the original tumor. Here, we present the development of a next-generation 3D organoid model derived from relapsed adult and pediatric FNRMS. This model preserves the molecular features of the patients' tumors and is expandable for several months in 3D, reinforcing its interest to drug combination screening with longitudinal efficacy monitoring. As a proof-of-concept, we demonstrate its preclinical relevance by reevaluating the therapeutic opportunities of targeting apoptosis in FNRMS from a streamlined approach based on transcriptomic data exploitation.

MYOD-SKP2 axis boosts tumorigenesis in fusion negative rhabdomyosarcoma by preventing differentiation through p57Kip2 targeting

Rhabdomyosarcomas (RMS) are pediatric mesenchymal-derived malignancies encompassing PAX3/7-FOXO1 Fusion Positive (FP)-RMS, and Fusion Negative (FN)-RMS with frequent RAS pathway mutations. RMS express the master myogenic transcription factor MYOD that, whilst essential for survival, cannot support differentiation. Here we discover SKP2, an oncogenic E3-ubiquitin ligase, as a critical pro-tumorigenic driver in FN-RMS. We show that SKP2 is overexpressed in RMS through the binding of MYOD to an intronic enhancer. SKP2 in FN-RMS promotes cell cycle progression and prevents differentiation by directly targeting p27Kip1 and p57Kip2, respectively. SKP2 depletion unlocks a partly MYOD-dependent myogenic transcriptional program and strongly affects stemness and tumorigenic features and prevents in vivo tumor growth. These effects are mirrored by the investigational NEDDylation inhibitor MLN4924. Results demonstrate a crucial crosstalk between transcriptional and post-translational mechanisms through the MYOD-SKP2 axis that contributes to tumorigenesis in FN-RMS. Finally, NEDDylation inhibition is identified as a potential therapeutic vulnerability in FN-RMS.

The epigenetic regulatory effect of histone acetylation and deacetylation on skeletal muscle metabolism-a review

Skeletal muscles, the largest organ responsible for energy metabolism in most mammals, play a vital role in maintaining the body's homeostasis. Epigenetic modification, specifically histone acetylation, serves as a crucial regulatory mechanism influencing the physiological processes and metabolic patterns within skeletal muscle metabolism. The intricate process of histone acetylation modification involves coordinated control of histone acetyltransferase and deacetylase levels, dynamically modulating histone acetylation levels, and precisely regulating the expression of genes associated with skeletal muscle metabolism. Consequently, this comprehensive review aims to elucidate the epigenetic regulatory impact of histone acetylation modification on skeletal muscle metabolism, providing invaluable insights into the intricate molecular mechanisms governing epigenetic modifications in skeletal muscle metabolism.

The influence of flow distribution strategy for the quantification of pressure- and wall shear stress-derived parameters in the coronary artery: A CTA-based computational fluid dynamics analysis

For image-based computational fluid dynamics (CFD) analysis to characterize the local coronary hemodynamic environment, the accuracy depends on the flow rate which is in turn associated with outlet branches' morphology. A good flow distribution strategy is important to mitigate the effect when certain branches cannot be considered. In this study, stenotic coronary arteries from 13 patients were used to analyze the effect of missing branches and different flow distribution strategies. Pressure- and wall shear stress (WSS)-derived parameters around the stenotic region (ROI) were compared, including fractional flow reserve (CT-FFR), instantaneous wave-free ratio (CT-iFR), resting distal to aortic coronary pressure (CT-Pd/Pa), time-averaged WSS, oscillatory shear index (OSI) and relative residence time (RRT). Three flow distribution strategies were the Huo-Kassab model at distal outlets (Type I), flow distribution based on outlet resistances (Type II), and a developed algorithm distributing flow at each bifurcation until the final outlets (Type III). Results showed that Type III strategy for models with truncated branch(es) had a good agreement in both pressure- and WSS-related results (interquatile range less than 0.12% and 4.02%, respectively) with the baseline model around the ROI. The relative difference of pressure- and WSS-related results were correlated with the flow differences in the ROI to the baseline mode. Type III strategy had the best performance in maintaining the flow in intermediate branches. It is recommended for CFD analysis. Removal of branches distal to a stenosis can be undertaken with an improved performance and maintained accuracy, while those proximal to the ROI should be kept.

Evaluating the effect of acupuncture on symptoms of diabetic peripheral neuropathy (DPN) among individuals with diabetic neuropathy: A single-blind, randomized trial study

Purpose

This study aimed to investigate the impact of acupuncture on Diabetic peripheral neuropathy (DPN) symptoms among individuals with diabetic neuropathy.

Methods

In a single-blind, randomized trial conducted between 2019 and 2020, 60 patients diagnosed with diabetic neuropathy were enrolled. These participants were randomly assigned to either the intervention or control group. The intervention group received real acupuncture alongside routine treatment once a week for seven sessions, each lasting 20 min. Meanwhile, the control group received sham acupuncture as an adjunct to their routine treatment, following the same schedule. To evaluate treatment efficacy, the study assessed primary outcomes, such as pain intensity measured using the Visual Analogue Scale (VAS). Secondary outcomes included evaluating fatigue severity and diabetic peripheral neuropathy (DPN) side effects, measured using the multidimensional fatigue inventory (MFI-20) and a standard questionnaire after each session.

Results

No statistically significant differences in pain and fatigue scores were observed between the two groups throughout all visits, even after adjusting for baseline characteristics, age, sex, type of diabetes, discopathy, and carpal tunnel syndrome parameters (P > 0.05). The findings did not provide strong evidence supporting a significant effect of real acupuncture compared to sham acupuncture on pain and fatigue values (P = 0.267 and 0.634, respectively). However, the 95% confidence interval for pain scores (-0.35, 1.28) was inconclusive, encompassing effect sizes favoring sham acupuncture.

Conclusion

Findings suggest that using acupuncture as an adjunctive therapy alongside routine treatment may not lead to a significant reduction in the symptoms of peripheral neuropathy and fatigue severity among individuals with diabetic neuropathy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01314-1.

Hedgehog pathway in sarcoma: from preclinical mechanism to clinical application

Sarcomas are a diverse group of malignant neoplasms of mesenchymal origin. They develop rarely, but due to poor prognosis, they are a challenging and significant clinical problem. Currently, available therapeutic options have very limited activity. A better understating of sarcomas' pathogenesis may help develop more effective therapies in the future. The Sonic hedgehog (Shh) signaling pathway is involved in both embryonic development and mature tissue repair and carcinogenesis. Shh pathway inhibitors are presently used in the treatment of basal cell carcinoma. Its increased activity has been demonstrated in many sarcomas, including osteosarcoma, Ewing sarcoma, chondrosarcoma, rhabdomyosarcoma, leiomyosarcoma, and malignant rhabdoid tumor. In vitro studies have demonstrated the effectiveness of inhibitors of the Hedgehog pathway in inhibiting proliferation in those sarcomas in which the components of the pathway are overexpressed. These results were confirmed by in vivo studies, which additionally proved the influence of Shh pathway inhibitors on limiting the metastatic potential of sarcoma cells. However, until now, the efficacy of sarcomas treatment with Shh pathway inhibitors has not been established in clinical trials. The reason for that may be the non-canonical activation of the pathway or interactions with other signaling pathways, such as Wnt or Notch. In this review, we present the Shh signaling pathway's role in the pathogenesis of sarcomas, including both canonical and non-canonical signaling. We also propose how this knowledge could be potentially translated into clinics.

Silent Killer in the Nose: Two Cases of Nasal Alveolar Rhabdomyosarcoma in Adults

We report two cases of nasal alveolar rhabdomyosarcoma (ARMS) in adult patients from our center who presented with local mass effect and systemic involvement. Our first patient had spontaneous unilateral epistaxis. Her blood investigation showed severe thrombocytopenia, and the bone marrow biopsy result showed bone marrow infiltration by non-hematopoietic malignant cells. Nasal endoscopy showed a mass arising medial to the left middle turbinate. Our second patient presented with right eye proptosis, associated with blurring of vision. Nasal endoscopy showed a right whitish nasal mass arising lateral to the middle turbinate. Both patients were diagnosed by immunohistochemical analysis showing ARMS, a soft tissue malignancy uncommon in adults. RMS in adults has a worse prognosis. Hence, the management is challenging. Early diagnostic workup is essential for the commencement of early treatment for better oncological outcomes.

A SNAI2/CTCF Interaction is Required for NOTCH1 Expression in Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a pediatric malignancy of the muscle with characteristics of cells blocked in differentiation. NOTCH1 is an oncogene that promotes self-renewal and blocks differentiation in the fusion negative-RMS sub-type. However, how NOTCH1 expression is transcriptionally maintained in tumors is unknown. Analyses of SNAI2 and CTCF chromatin binding and HiC analyses revealed a conserved SNAI2/CTCF overlapping peak downstream of the NOTCH1 locus marking a sub-topologically associating domain (TAD) boundary. Deletion of the SNAI2-CTCF peak showed that it is essential for NOTCH1 expression and viability of FN-RMS cells. Reintroducing constitutively activated NOTCH1-ΔE in cells with the SNAI2-CTCF peak deleted restored cell-viability. Ablation of SNAI2 using CRISPR/Cas9 reagents resulted in the loss of majority of RD and SMS-CTR FN-RMS cells. However, the few surviving clones that repopulate cultures have recovered NOTCH1. Cells that re-establish NOTCH1 expression after SNAI2 ablation are unable to differentiate robustly as SNAI2 shRNA knockdown cells; yet, SNAI2-ablated cells continued to be exquisitely sensitive to ionizing radiation. Thus, we have uncovered a novel mechanism by which SNAI2 and CTCF maintenance of a sub-TAD boundary promotes rather than represses NOTCH1 expression. Further, we demonstrate that SNAI2 suppression of apoptosis post-radiation is independent of SNAI2/NOTCH1 effects on self-renewal and differentiation.

PKCδ regulates the vascular biology in diabetic atherosclerosis

Diabetes mellitus, known for its complications, especially vascular complications, is becoming a globally serious social problem. Atherosclerosis has been recognized as a common vascular complication mechanism in diabetes. The diacylglycerol (DAG)-protein kinase C (PKC) pathway plays an important role in atherosclerosis. PKCs can be divided into three subgroups: conventional PKCs (cPKCs), novel PKCs (nPKCs), and atypical PKCs (aPKCs). The aim of this review is to provide a comprehensive overview of the role of the PKCδ pathway, an isoform of nPKC, in regulating the function of endothelial cells, vascular smooth muscle cells, and macrophages in diabetic atherosclerosis. In addition, potential therapeutic targets regarding the PKCδ pathway are summarized. Video Abstract.

PAX3-FOXO1 dictates myogenic reprogramming and rhabdomyosarcoma identity in endothelial progenitors

Fusion-positive rhabdomyosarcoma (FP-RMS) driven by the expression of the PAX3-FOXO1 (P3F) fusion oncoprotein is an aggressive subtype of pediatric rhabdomyosarcoma. FP-RMS histologically resembles developing muscle yet occurs throughout the body in areas devoid of skeletal muscle highlighting that FP-RMS is not derived from an exclusively myogenic cell of origin. Here we demonstrate that P3F reprograms mouse and human endothelial progenitors to FP-RMS. We show that P3F expression in aP2-Cre expressing cells reprograms endothelial progenitors to functional myogenic stem cells capable of regenerating injured muscle fibers. Further, we describe a FP-RMS mouse model driven by P3F expression and Cdkn2a loss in endothelial cells. Additionally, we show that P3F expression in TP53-null human iPSCs blocks endothelial-directed differentiation and guides cells to become myogenic cells that form FP-RMS tumors in immunocompromised mice. Together these findings demonstrate that FP-RMS can originate from aberrant development of non-myogenic cells driven by P3F.

Imaging cellular forces with photonic crystals

Current techniques for visualizing and quantifying cellular forces have limitations in live cell imaging, throughput, and multi-scale analysis, which impede progress in cell force research and its practical applications. We developed a photonic crystal cellular force microscopy (PCCFM) to image vertical cell forces over a wide field of view (1.3 mm ⨯ 1.0 mm, a 10 ⨯ objective image) at high speed (about 20 frames per second) without references. The photonic crystal hydrogel substrate (PCS) converts micro-nano deformations into perceivable color changes, enabling in situ visualization and quantification of tiny vertical cell forces with high throughput. It enabled long-term, cross-scale monitoring from subcellular focal adhesions to tissue-level cell sheets and aggregates.

CD276-CAR T cells and Dual-CAR T cells targeting CD276/FGFR4 promote rhabdomyosarcoma clearance in orthotopic mouse models

BACKGROUND

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in childhood, whose prognosis is still poor especially for metastatic, high-grade, and relapsed RMS. New treatments are urgently needed, especially systemic therapies. Chimeric Antigen Receptor T cells (CAR Ts) are very effective against hematological malignancies, but their efficacy against solid tumors needs to be improved. CD276 (B7-H3) is a target upregulated in RMS and detected at low levels in normal tissues. FGFR4 is a very specific target for RMS. Here, we optimized CAR Ts for these two targets, alone or in combination, and tested their anti-tumor activity in vitro and in vivo.

METHODS

Four different single-domain antibodies were used to select the most specific FGFR4-CAR construct. RMS cell killing and cytokine production by CD276- and FGFR4-CAR Ts expressing CD8α or CD28 HD/TM domains in combination with 4-1BB and/or CD28 co-stimulatory domains were tested in vitro. The most effective CD276- and FGFR4-CAR Ts were used to generate Dual-CAR Ts. Tumor killing was evaluated in vivo in three orthotopic RMS mouse models.

RESULTS

CD276.V-CAR Ts (276.MG.CD28HD/TM.CD28CSD.3ζ) showed the strongest killing of RMS cells, and the highest release of IFN-γ and Granzyme B in vitro. FGFR4.V-CAR Ts (F8-FR4.CD28HD/TM.CD28CSD.3ζ) showed the most specific killing. CD276-CAR Ts successfully eradicated RD- and Rh4-derived RMS tumors in vivo, achieving complete remission in 3/5 and 5/5 mice, respectively. In CD276low JR-tumors, however, they achieved complete remission in only 1/5 mice. FGFR4 CAR Ts instead delayed Rh4 tumor growth. Dual-CAR Ts promoted Rh4-tumors clearance in 5/5 mice.

CONCLUSIONS

CD276- and CD276/FGFR4-directed CAR Ts showed effective RMS cell killing in vitro and eradication of CD276high RMS tumors in vivo. CD276low tumors escaped the therapy highlighting a correlation between antigen density and effectiveness. FGFR4-CAR Ts showed specific killing in vitro but could only delay RMS growth in vivo. Our results demonstrate that combined expression of CD276-CAR with other CAR does not reduce its benefit. Introducing immunotherapy with CD276-CAR Ts in RMS seems to be feasible and promising, although CAR constructs design and target combinations have to be further improved to eradicate tumors with low target expression.

Rhabdomyosarcoma: Current Therapy, Challenges, and Future Approaches to Treatment Strategies

Rhabdomyosarcoma is a rare cancer arising in skeletal muscle that typically impacts children and young adults. It is a worldwide challenge in child health as treatment outcomes for metastatic and recurrent disease still pose a major concern for both basic and clinical scientists. The treatment strategies for rhabdomyosarcoma include multi-agent chemotherapies after surgical resection with or without ionization radiotherapy. In this comprehensive review, we first provide a detailed clinical understanding of rhabdomyosarcoma including its classification and subtypes, diagnosis, and treatment strategies. Later, we focus on chemotherapy strategies for this childhood sarcoma and discuss the impact of three mechanisms that are involved in the chemotherapy response including apoptosis, macro-autophagy, and the unfolded protein response. Finally, we discuss in vivo mouse and zebrafish models and in vitro three-dimensional bioengineering models of rhabdomyosarcoma to screen future therapeutic approaches and promote muscle regeneration.

Inhibition of NAD+-Dependent Metabolic Processes Induces Cellular Necrosis and Tumor Regression in Rhabdomyosarcoma Models

PURPOSE

Deregulated metabolism in cancer cells represents a vulnerability that may be therapeutically exploited to benefit patients. One such target is nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD+ salvage pathway. NAMPT is necessary for efficient NAD+ production and may be exploited in cells with increased metabolic demands. We have identified NAMPT as a dependency in rhabdomyosarcoma (RMS), a malignancy for which novel therapies are critically needed. Here we describe the effect of NAMPT inhibition on RMS proliferation and metabolism in vitro and in vivo.

EXPERIMENTAL DESIGN

Assays of proliferation and cell death were used to determine the effects of pharmacologic NAMPT inhibition in a panel of ten molecularly diverse RMS cell lines. Mechanism of the clinical NAMPTi OT-82 was determined using measures of NAD+ and downstream NAD+-dependent functions, including energy metabolism. We used orthotopic xenograft models to examine tolerability, efficacy, and drug mechanism in vivo.

RESULTS

Across all ten RMS cell lines, OT-82 depleted NAD+ and inhibited cell growth at concentrations ≤1 nmol/L. Significant impairment of glycolysis was a universal finding, with some cell lines also exhibiting diminished oxidative phosphorylation. Most cell lines experienced profound depletion of ATP with subsequent irreversible necrotic cell death. Importantly, loss of NAD and glycolytic activity were confirmed in orthotopic in vivo models, which exhibited complete tumor regressions with OT-82 treatment delivered on the clinical schedule.

CONCLUSIONS

RMS is highly vulnerable to NAMPT inhibition. These findings underscore the need for further clinical study of this class of agents for this malignancy.

Common queries in managing rhabdomyosarcoma in low- and middle-income countries: An Indo-North American collaboration

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma among children and adolescents. The management of RMS involves risk stratification of the patients based on various clinicopathological characteristics. The multimodality treatment approach requires chemotherapy, surgery, and/or radiation. The treatment of RMS necessitates the involvement of multiple disciplines, such as pathology, pediatric oncology, surgery, and radiation oncology. The disease heterogeneity, molecular testing, evolving treatment regimens, and limited resources are some of the challenges faced by clinicians while treating a patient with RMS in low- and middle-income countries (LMICs). In this review, we endeavor to bring experts from varying fields to address clinicians' common questions while managing a child or adolescent with RMS in LMICs. This review is most applicable to level 2 centers in LMICs as per the levels of services described by the Adapted Treatment Regimens Working Group of the Pediatric Oncology in Developing Countries committee of the International Society of Pediatric Oncology.

Which Patients With Rhabdomyosarcoma Need Radiotherapy? Analysis of the Radiotherapy Strategies of the CWS-96 and CWS-2002P Studies and SoTiSaR Registry

PURPOSE

To analyze and compare the indications, doses, and application methods of radiotherapy (RT) and their influence on prognosis of patients with localized rhabdomyosarcoma (RMS).

METHODS

One thousand four hundred seventy patients with localized RMS 21 years and younger entered on CWS-96, CWS-2002P, and SoTiSaR were eligible for the analysis. The median follow-up was 6.5 years (IQR, 3.3-9.5).

RESULTS

The 5-year event-free survival (EFS) and local control survival (LCS) for 910 (62%) irradiated versus nonirradiated patients were 71% versus 69% and 78% versus 73% (P = .03), respectively. Ninety-five percent of patients in IRS I (90% embryonal RMS [eRMS]) were nonirradiated (EFS, 87%). Irradiated patients with IRS II had improved LCS (91% v 80%; P = .01) and EFS (not significant). In IRS III, EFS and LCS were significantly better for RT patients: 71% versus 56% (P = 3.1e-06) and 76% versus 61% (P = 4.1e-07). Patients with tumors in the head and neck region (orbita, parameningeal, and nonparameningeal) and in other sites had significantly better EFS and LCS and in parameningeal also overall survival (OS). The efficacy of low RT doses of 32 Gy (hyperfractionated, accelerated RT [HART]) and 36 and 41.4 Gy (conventional fractionated RT [CFRT]) in the favorable groups and higher doses of 44.8 Gy (HART) and 50.4 and 55.4 Gy (CFRT) in the unfavorable groups was comparable. Proton RT was used predominantly in head/neck-parameningeal (HN-PM) tumors, with similar EFS and LCS to photon RT.

CONCLUSION

RT can be omitted in patients with IRS I eRMS. RT improves LCS and EFS in IRS II and III. RT improves OS in patients with HN-PM, with proton RT comparable with photon RT. Doses of 32 Gy (HART) or 36 and 41.4 Gy (CFRT) had comparable efficacy in patients with favorable risk profiles and 44.8 Gy (HART) or 50.4 and 55.8 Gy (CFRT) in the unfavorable groups.

Staufen1 controls mitochondrial metabolism via HIF2α in embryonal rhabdomyosarcoma and promotes tumorigenesis

Elevated mitochondrial metabolism promotes tumorigenesis of Embryonal Rhabdomyosarcomas (ERMS). Accordingly, targeting oxidative phosphorylation (OXPHOS) could represent a therapeutic strategy for ERMS. We previously demonstrated that genetic reduction of Staufen1 (STAU1) levels results in the inhibition of ERMS tumorigenicity. Here, we examined STAU1-mediated mechanisms in ERMS and focused on its potential involvement in regulating OXPHOS. We report the novel and differential role of STAU1 in mitochondrial metabolism in cancerous versus non-malignant skeletal muscle cells (NMSkMCs). Specifically, our data show that STAU1 depletion reduces OXPHOS and inhibits proliferation of ERMS cells. Our findings further reveal the binding of STAU1 to several OXPHOS mRNAs which affects their stability. Indeed, STAU1 depletion reduced the stability of OXPHOS mRNAs, causing inhibition of mitochondrial metabolism. In parallel, STAU1 depletion impacted negatively the HIF2α pathway which further modulates mitochondrial metabolism. Exogenous expression of HIF2α in STAU1-depleted cells reversed the mitochondrial inhibition and induced cell proliferation. However, opposite effects were observed in NMSkMCs. Altogether, these findings revealed the impact of STAU1 in the regulation of mitochondrial OXPHOS in cancer cells as well as its differential role in NMSkMCs. Overall, our results highlight the therapeutic potential of targeting STAU1 as a novel approach for inhibiting mitochondrial metabolism in ERMS.

Preclinical development of a chimeric antigen receptor T cell therapy targeting FGFR4 in rhabdomyosarcoma

Pediatric patients with relapsed or refractory rhabdomyosarcoma (RMS) have dismal cure rates, and effective therapy is urgently needed. The oncogenic receptor tyrosine kinase fibroblast growth factor receptor 4 (FGFR4) is highly expressed in RMS and lowly expressed in healthy tissues. Here, we describe a second-generation FGFR4-targeting chimeric antigen receptor (CAR), based on an anti-human FGFR4-specific murine monoclonal antibody 3A11, as an adoptive T cell treatment for RMS. The 3A11 CAR T cells induced robust cytokine production and cytotoxicity against RMS cell lines in vitro. In contrast, a panel of healthy human primary cells failed to activate 3A11 CAR T cells, confirming the selectivity of 3A11 CAR T cells against tumors with high FGFR4 expression. Finally, we demonstrate that 3A11 CAR T cells are persistent in vivo and can effectively eliminate RMS tumors in two metastatic and two orthotopic models. Therefore, our study credentials CAR T cell therapy targeting FGFR4 to treat patients with RMS.

Complete loss of TP53 and RB1 is associated with complex genome and low immune infiltrate in pleomorphic rhabdomyosarcoma

Rhabdomyosarcoma accounts for roughly 1% of adult sarcomas, with pleomorphic rhabdomyosarcoma (PRMS) as the most common subtype. Survival outcomes remain poor for patients with PRMS, and little is known about the molecular drivers of this disease. To better characterize PRMS, we performed a broad array of genomic and immunostaining analyses on 25 patient samples. In terms of gene expression and methylation, PRMS clustered more closely with other complex karyotype sarcomas than with pediatric alveolar and embryonal rhabdomyosarcoma. Immune infiltrate levels in PRMS were among the highest observed in multiple sarcoma types and contrasted with low levels in other rhabdomyosarcoma subtypes. Lower immune infiltrate was associated with complete loss of both TP53 and RB1. This comprehensive characterization of the genetic, epigenetic, and immune landscape of PRMS provides a roadmap for improved prognostications and therapeutic exploration.

Clinical Insight on Proton Therapy for Paediatric Rhabdomyosarcoma

This paper offers an insight into the use of Proton Beam Therapy (PBT) in paediatric patients with rhabdomyosarcoma (RMS). This paper provides a comprehensive analysis of the literature, investigating comparative photon-proton dosimetry, outcome, and toxicity. In the complex and multimodal scenario of the treatment of RMS, clear evidence of the therapeutic superiority of PBT compared to other modern photon techniques has not yet been demonstrated; however, PBT can be considered an excellent treatment option, in particular for young children and patients with specific primary sites, such as the head and neck area (and especially the parameningeal regions), genito-urinary, pelvic, and paravertebral regions. The unique depth-dose characteristics of protons can be exploited to achieve significant reductions in normal tissue doses and may allow an escalation of tumour doses and greater sparing of normal tissues, thus potentially improving local control while at the same time reducing toxicity and improving quality of life. However, access of children with RMS (and more in general with solid tumors) to PBT remains a challenge, due to the limited number of available proton therapy installations.

Piperacetazine Directly Binds to the PAX3::FOXO1 Fusion Protein and Inhibits Its Transcriptional Activity

The tumor-specific chromosomal translocation product, PAX3::FOXO1, is an aberrant fusion protein that plays a key role for oncogenesis in the alveolar subtype of rhabdomyosarcoma (RMS). PAX3::FOXO1 represents a validated molecular target for alveolar RMS and successful inhibition of its oncogenic activity is likely to have significant clinical applications. Even though several PAX3::FOXO1 function-based screening studies have been successfully completed, a directly binding small-molecule inhibitor of PAX3::FOXO1 has not been reported. Therefore, we screened small-molecule libraries to identify compounds that were capable of directly binding to PAX3::FOXO1 protein using surface plasmon resonance technology. Compounds that directly bound to PAX3::FOXO1 were further evaluated in secondary transcriptional activation assays. We discovered that piperacetazine can directly bind to PAX3::FOXO1 protein and inhibit fusion protein-derived transcription in multiple alveolar RMS cell lines. Piperacetazine inhibited anchorage-independent growth of fusion-positive alveolar RMS cells but not embryonal RMS cells. On the basis of our findings, piperacetazine is a molecular scaffold upon which derivatives could be developed as specific inhibitors of PAX3::FOXO1. These novel inhibitors could potentially be evaluated in future clinical trials for recurrent or metastatic alveolar RMS as novel targeted therapy options.

SIGNIFICANCE

RMS is a malignant soft-tissue tumor mainly affecting the pediatric population. A subgroup of RMS with worse prognosis harbors a unique chromosomal translocation creating an oncogenic fusion protein, PAX3::FOXO1. We identified piperacetazine as a direct inhibitor of PAX3::FOXO1, which may provide a scaffold for designing RMS-specific targeted therapy.

Antitumor activity of natural pigment violacein against osteosarcoma and rhabdomyosarcoma cell lines

PURPOSE

Sarcomas are rare and heterogenic tumors with unclear etiology. They develop in bone and connective tissue, mainly in pediatric patients. To increase efficacy of current therapeutic options, natural products showing selective toxicity to tumor cells are extensively investigated. Here, we evaluated antitumor activity of bacterial pigment violacein in osteosarcoma (OS) and rhabdomyosarcoma (RMS) cell lines.

METHODS

The toxicity of violacein was assessed in vitro and in vivo, using MTT assay and FET test. The effect of violacein on cell migration was monitored by wound healing assay, cell death by flow cytometry, uptake of violacein by fluorescence microscopy, generation of reactive oxygen species (ROS) by DCFH-DA assay and lipid peroxidation by TBARS assay.

RESULTS

Violacein IC50 values for OS and RMS cells were in a range from 0.35 to 0.88 µM. Its selectivity toward malignant phenotype was confirmed on non-cancer V79-4 cells, and it was safe in vivo, for zebrafish embryos in doses up to 1 µM. Violacein induced apoptosis and affected the migratory potential of OS and RMS cells. It was found on the surfaces of tested cells. Regarding the mechanism of action, violacein acted on OS and RMS cells independently of oxidative signaling, as judged by no increase in intracellular ROS generation and no lipid peroxidation.

CONCLUSION

Our study provided further evidence that reinforces the potential of violacein as an anticancer agent and candidate to consider for improvement of the effectiveness of traditional OS and RMS therapies.

The modulation of iron metabolism affects the Rhabdomyosarcoma tumor growth in vitro and in vivo

Rhabdomyosarcoma (RMS) is an aggressive rare neoplasm that derives from mesenchymal cells, which frequently develops resistance to the current therapies and the formation of metastases. Thus, new therapies are needed. The alteration of iron metabolism in cancer cells was effective in reducing the progression of many tumors but not yet investigated in RMS. Here we investigated the effect of iron modulation in RMS both in vitro and in vivo. We first characterized the most used RMS cell lines representing the most common subtypes, embryonal (ERMS, RD cells) and alveolar (ARMS, RH30 cells), for their iron metabolism, in basal condition and in response to its modulation. Then we investigated the effects of both iron overload and chelation strategies in vitro and in vivo. RMS cell lines expressed iron-related proteins, even if at lower levels compared to hepatic cell lines and they are correctly modulated in response to iron increase and deprivation. Interestingly, the treatment with different doses of ferric ammonium citrate (FAC, as iron source) and with deferiprone (DFP, as iron chelator), significantly affected the cell viability of RD and RH30. Moreover, iron supplementation (in the form of iron dextran) or iron chelation (in the form of DFP) were also effective in vivo in inhibiting the tumor mass growth both derived from RD and RH30 with iron chelation treatment the most effective one. All the data suggest that the iron modulation could be a promising approach to overcome the RMS tumor growth. The mechanism of action seems to involve the apoptotic cell death for both iron supplementation and chelation with the concomitant induction of ferroptosis in the case of iron supplementation.

SIX1 as a Novel Immunohistochemical Marker in the Differential Diagnosis of Rhabdomyosarcoma

Background: Differential diagnosis of rhabdomyosarcoma (RMS) is challenging. Sineoculis homeobox homolog 1 (SIX1) is an oncogene involved in skeletal muscle differentiation. We compared protein expression patterns of SIX1 in RMS and its most common differential diagnoses. Methods: SIX1 immunohistochemistry in 36 RMS and in 33 tumors from seven differential diagnostic subtypes were evaluated. The fraction of SIX1 positive tumor cells was scored by three independent observers. Results: A majority (75%) of the evaluated RMS expressed SIX1 in at least 50% of tumor cells and all except one RMS had more than 25% positive tumor cells. Neuroblastoma had less than 1% SIX1 positive tumor cells. Gonadoblastoma, malignant rhabdoid tumor, and Ewing sarcoma had 10% or less positive tumor cells. Pleuropulmonary blastoma exhibited 26-50% positive tumor cells and synovial sarcoma >50% positive cells. Conclusion: SIX1 immunohistochemistry is positive in most RMS, and occasionally in some tumors within the differential diagnoses of RMS.

Case Report: A 13-year-old adolescent diagnosed as malignant phyllodes tumor combined with rhabdomyosarcoma differentiation

Phyllodes tumor (PT) is an infrequent type of breast neoplasm, constituting a mere 0.5%-1.5% of the entirety of breast tumors. The malignant phyllodes tumor (MPT) comprises only 15% of all phyllodes tumors, and its transformation into rhabdomyosarcoma (RMS) is exceedingly rare in clinical practice. Given its insensitivity to chemotherapy and radiotherapy, treatment options for MPT patients are limited, leaving complete surgical resection as the only option. Therefore, it is imperative to investigate the effective utilization of the heterogeneous differentiation characteristics of MPT to expand treatment alternatives for these patients. In this case report, we represent a 13-year-old adolescent diagnosed with giant breast MPT with RMS differentiation and pulmonary metastasis. The initial step in the treatment process involved radical surgical resection, followed by the administration of four cycles of VDC/IC chemotherapy, which is widely recognized as the standard chemotherapy for RMS. Regrettably, the delay in initiating chemotherapy resulted in minimal observable changes in the size of the pulmonary metastatic nodule. Additionally, a comprehensive literature review on the characterization of MPT with heterogeneous differentiation was conducted to enhance comprehension of the diagnosis and treatment of this uncommon disease in clinical practice. Meanwhile, this case also reminds the doctors that when we diagnose a patient as MPT, it is crucial to consider its heterogenous nature and promptly initiate adjuvant treatment. By targeting the differentiation element of MPT, it becomes feasible to overcome the previously perceived limitation of surgical intervention as the sole treatment option.

Novel iodoquinazolinones bearing sulfonamide moiety as potential antioxidants and neuroprotectors

In a search for new antioxidants, a set of new iodoquinazolinone derivatives bearing benzenesulfonamide moiety and variable acetamide pharmacophores 5-17 were designed and synthesized. The structures of the synthesized compounds were confirmed based on spectral data. Compounds 5-17 were screened using in vitro assay for their antioxidant potential and acetylcholinesterase (AChE) inhibitory activity. The 2-(6-iodo-4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-ylthio)-N-(pyrazin-2-yl) acetamide 14 was the most active scaffold with potent AChE inhibitory activity. Compound 14 showed relative safety with a median lethal dose of 300 mg/kg (LD50 = 300 mg/kg), in an acute toxicity study. The possible antioxidant and neuroprotective activities of 14 were evaluated in irradiated mice. Compound 14 possessed in vivo AChE inhibitory activity and was able to modify the brain neurotransmitters. It was able to cause mitigation of gamma radiation-induced oxidative stress verified by the decline in Myeloperoxidase (MPO) and increase of glutathione (GSH) levels. Also, 14 restored the alterations in behavioral tests. Molecular docking of 14 was performed inside MPO and AChE active sites and showed the same binding interactions as that of the co-crystallized ligands considering the binding possibilities and energy scores. These findings would support that 14 could be considered a promising antioxidant with a neuromodulatory effect.

Comparison of 18F-FDG PET/CT and 68Ga-FAPI in Spindle Cell Rhabdomyosarcoma

We report a rare case of spindle cell rhabdomyosarcoma. Sarcomas generally exhibit an abnormal increased FDG uptake on 18F-FDG PET/CT imaging, while spindle cell rhabdosarcomas exhibits a significantly increased lesion uptake on 68Ga FAPI PET/CT imaging compared to 18F-FDG. This case suggests that 68Ga-FAPI PET/CT has potential value in evaluating spindle cell rhabdomyosarcoma.