Citations

Abstract Ewing sarcoma is an aggressive pediatric cancer that has remained refractory to current therapeutics. Immunotherapy has been unsuccessful in Ewing sarcoma, largely due to poor understanding of how its immune tumor microenvironment is regulated. We recently demonstrated that ubiquitin-specific protease 6 (USP6) can remodel the Ewing sarcoma immune landscape to engender an antitumorigenic tumor microenvironment. USP6 expression in Ewing sarcoma cells enhances surface expression of immunostimulatory ligands and receptors and induces production of multiple chemokines, driving recruitment and activation of tumor-suppressive immune lineages, including NK cells. We sought to harness this multifaceted immunostimulatory function into a novel therapeutic by delivering in vitro transcribed USP6 mRNA via ionizable lipid nanoparticles (LNP). Treatment of Ewing sarcoma cells with USP6 mRNA in vitro is capable of inducing the aforementioned antitumorigenic and immunostimulatory responses. In addition, USP6 mRNA–treated Ewing sarcoma cells elicit cytolytic activation of primary human CD8+ and CD4+ T lymphocytes and NK cells in vitro. Intratumoral delivery of USP6 mRNA LNPs suppresses growth of Ewing sarcoma xenografts, coincident with increased immune infiltration and activation. We further demonstrate that USP6 mRNA is capable of igniting an immunostimulatory program in other cancer types (including acute myeloid leukemia, melanoma, prostate cancer, head and neck cancer, and osteosarcoma) in vitro and suppressing acute myeloid leukemia xenograft growth in vivo. Treatment with USP6 mRNA LNPs was well-tolerated, with no observed gross toxicity. Together, these preclinical studies provide proof-of-concept for the immunogenic and antitumorigenic efficacy of USP6 mRNA LNPs and support its promise as a novel immunotherapeutic in diverse cancer types.

ABSTRACT Background Atherothrombosis, the main event leading to acute coronary syndrome (ACS), is strongly linked to disturbed blood flow (d-flow) regions. Although the involvement of the Hippo pathway and its kinases Large Tumor Suppressor Kinase 1and 2 (LATS 1 and 2) in mechanical stress responses is known, the mechanisms by which d-flow simultaneously induces senescence, proliferation, and atherothrombosis remain unclear. Methods The role of endothelial cells (EC)-specific LATS1/2 was examined using EC specific knock-out (EKO) mice in a partial left carotid ligation (PLCL) model. Plaque spatial multi-omics analysis was performed by integrating imaging mass cytometry, sequential immunofluorescence (COMET™), and spatial metabolomics at the single-cell level in human and mouse atherosclerotic plaques. Results In tamoxifen-inducible Lats1 homo( -/- ) / Lats2 homo( -/- ) EC-specific knockout (EKO) mice, deletion of LATS1/2 induced by tamoxifen led to fatal outcomes, characterized by severe systemic edema and markedly increased vascular permeability. In contrast, Lats1 het(+ /- ) / Lats2 homo( -/- ) -EKO mice survived and developed atherothrombotic plaques exhibiting neovascularization even without further additional dietary or genetic intervention. Spatial proteomics analysis revealed that LATS1/2 depletion in ECs triggered a senescence-associated stemness (SAS) phenotype, primarily driven by CD38 upregulation. Complementary spatial metabolomics profiling demonstrated a significant increase in sulfite and taurine within LATS1/2-deficient plaques, indicating lowered sulfite oxidase (SUOX) activity. Mechanistically, CD38 upregulation was found to suppress SUOX expression, induce the reverse mode of mitochondrial complex V, and increase succinate dehydrogenase (SDH) activity along with ATP consumption. Paradoxically, despite ATP depletion, this metabolic disturbance enhanced glutamate metabolism and the tricarboxylic acid (TCA) cycle, sustaining EC proliferation under energetically stressed conditions. The combined effect of LATS1/2 deletion and CD38 activation established a unique EC phenotype defined by increased SAS, leading to proliferation, senescence, and eventual cell death. These pathological processes culminated in the formation of atherothrombotic plaques, which were attenuated by inhibition of CD38. Notably, a similar phenotype—marked by metabolically active ECs—was observed in human atherothrombotic plaques, suggesting translational relevance. Conclusion Loss of LATS1/2 in ECs induces SAS state that promotes excessive EC proliferation, senescent cell accumulation, and the development of structurally fragile, leaky neo vessels—hallmarks of atherothrombotic lesions. CD38-mediated SUOX deficiency further amplifies this pathological process by inducing mitochondrial dysfunction, depleting ATP, and triggering compensatory upregulation of glutamate and TCA cycle metabolism. These findings identify a novel LATS1/2–CD38–SUOX axis in ECs that orchestrates SAS-driven atherothrombosis. Targeting CD38 may represent a promising therapeutic strategy to mitigate vascular dysfunction and plaque instability in high-risk ACS patients. Graphical abstract Under normal physiological conditions, LATS1/2 and Lamin A work together to suppress CD38 expression. Lamin A binds directly to the CD38 promoter to repress transcription, and LATS1/2 interact with Lamin A to reinforce this suppression. This collaboration helps maintain low CD38 activity and preserves cellular NAD⁺ levels. However, under disturbed flow (d-flow), both LATS1/2 and Lamin A are downregulated. The loss of this dual repression leads to increased CD38 NADase expression. Elevated CD38 accelerates NAD⁺ consumption, causing NAD⁺ depletion—a hallmark of cellular senescence. Reduced NAD⁺ disrupts key metabolic and stress-response pathways, contributing to the onset of the senescent state. At the same time, CD38 suppresses sulfite oxidase (SUOX), leading to sulfite accumulation and mitochondrial redox imbalance. This shift activates the reverse mode of mitochondrial Complex V, which decreases ATP production and increases mitochondrial ROS, intensifying metabolic and oxidative stress in endothelial cells (ECs). In response, ECs compensate by upregulating succinate dehydrogenase (SDH), enhancing TCA cycle activity and glutamate metabolism. This metabolic adaptation provides the biosynthetic building blocks needed for cell growth and proliferation. As a result, ECs adopt a paradoxical phenotype: they show classical features of stress-induced senescence (such as NAD⁺ depletion, oxidative stress, and cell cycle arrest signals), while simultaneously undergoing metabolic activation and proliferation, also mediated by YAP. This defines a non-canonical endothelial program known as senescence-associated stemness (SAS), characterized by the formation of abnormal, proliferative, yet fragile neovessels. These dysfunctional vessels contribute to atherothrombosis, setting this process apart from the more stable lesions typical of conventional atherosclerosis.

PURPOSE Survivors of adolescent and young adult (AYA)-onset cancers require comprehensive cancer surveillance care. Guidelines recommend 1-4 clinician visits annually for 5 years depending on stage and disease. The goal of this study was to identify factors associated with patterns of post-treatment primary and oncology care in a large cohort of survivors of AYA-onset cancers diagnosed within an integrated health care system. METHODS Patients diagnosed with cancer between 2006 and 2020 age 15-39 years were included. Surveillance visits were identified from electronic medical records 2-5 years after diagnosis. Multivariable logistic regression was used to assess associations with zero oncology specialty visits. RESULTS Of 7,925 survivors, 46% were Hispanic, 6% non-Hispanic Black, 11% non-Hispanic Asian, 35% non-Hispanic White, and 65% female. One-quarter had no oncology specialty visits in the first surveillance year rising to 38% in year 5; 31% had 3+ visits in the first year, declining to 13% in year 5. Over the surveillance period, 17% did not have any oncology specialty visits and 6% had no primary care or oncology visits. Those who were male (odds ratio [OR], 1.21 [95% CI, 1.02 to 1.45]), 20-24 years at diagnosis (OR, 1.58, 95% CI, 1.27 to 1.9; v 35 to 39), or non-Hispanic Black (OR, 1.38, 95% CI, 1.05 to 1.82; v non-Hispanic White) or had high-deductible commercial or Medicaid insurance (OR, 1.35, 95% CI, 1.15 to 1.59; OR, 1.42, 95% CI, 1.11 to 1.82, respectively; v no or low deductible commercial) were more likely to be in the 0-visit group for oncology specialty care. CONCLUSION Although the majority of this cohort received either primary or oncology specialty care, our study identifies those who may need tailored outreach for follow-up care. Continued research into development and testing of interventions to improve uptake of appropriate health care for survivors of AYA-onset cancers is critical.

Purpose To establish international expert consensus on surgical techniques, complications, and rehabilitation protocols for lateral extra‐articular procedures (LEAPs) performed adjunctively with anterior cruciate ligament reconstruction. Methods Fifty‐five knee surgeons from 17 countries on 5 continents completed a 3‐round modified Delphi process. In the final round, 16 statements on LEAP techniques and complications were scored on a 5‐point Likert scale; ≥75% “agree/strongly agree” constituted consensus. When appropriate, strength of recommendation was graded. Statements lacking support were revised until consensus or abandonment. Results Six statements achieved unanimous consensus (100%), 2 had strong consensus (90%‐99.9%), and 3 reached consensus (75%‐89.9%); 4 were removed. Key technical recommendations were as follows: (1) in iliotibial band procedures, the graft strip should pass beneath the lateral collateral ligament; (2) an anatomic technique is mandatory for anterolateral ligament reconstruction; and (3) no single LEAP is clinically superior to another. Unanimous agreement indicated that modern LEAPs do not increase lateral compartment osteoarthritis risk, carry a low complication rate, and do not necessitate changes to rehabilitation or return‐to‐play timelines. Conclusions Consensus defined core surgical principles and confirmed the safety of adding LEAPs to anterior cruciate ligament reconstruction. When an iliotibial band graft is used, it should be routed deep to the lateral collateral ligament and fixed between 0° and 60° of knee flexion under low tension. For anterolateral ligament reconstruction, femoral fixation should be in full extension at a posterior‐proximal point relative to the lateral epicondyle. Although no single LEAP proved superiority, adherence to these principles permits safe, effective surgery without altering standard rehabilitation or return‐to‐sport protocols and without increasing osteoarthritis risk. Level of Evidence Level V, expert opinion.

Purpose To define expert consensus on whether and how lateral extra‐articular procedures (LEAPs) should accompany anterior cruciate ligament (ACL) reconstruction to optimize outcomes in ACL‐deficient knees. Methods Fifty‐five knee surgeons from 17 countries on 5 continents completed a 3‐round modified Delphi process. Twenty‐one statements on patient selection for combined ACL reconstruction (ACLR) + LEAPs were graded on 5‐point Likert scales; ≥75% “agree/strongly agree” signified consensus. Strength of recommendation was ranked, and statements failing the threshold were revised or discarded after discussion. Results One statement achieved unanimous agreement (100%): it is strongly recommended to add a LEAP for active patients ≤25 years receiving hamstring‐autograft ACLR to reduce graft failure. Strong consensus (≥90%) supported LEAPs in primary ACLR when grade 3 pivot shift (97.9%), knee hyperextension (97.9%), skeletally immature status (79.5%), revision ACLR (91.5%), return to pivoting sports (93.2%), active patients ≤25 years using nonhamstring grafts (90.7%), grade 3 Lachman test (90%), and when multiple relative risk factors coexist (statement 36, 97.1%). Consensus (75%‐89.9%) favored LEAPs for chronic symptomatic ACL deficiency (86.1%), posterior tibial slope >12° (85.7%), and a history of contralateral ACL injury (88.9%). Eight statements did not reach consensus regarding small‐diameter autografts, female athletes, imaging signs of anterolateral injury (e.g., Segond fracture, lateral femoral‐notch sign), and concomitant meniscal procedures. One statement on LEAPs with primary ACL repair was withdrawn because the project focused on reconstruction. Conclusions International experts strongly recommend adding a LEAP in young active patients undergoing hamstring‐autograft ACLR and in cases of high‐grade rotational or anterior laxity, knee hyperextension, revision surgery, or returning to pivoting sports. Unresolved issues include small graft size, female athletes, imaging findings of rotational instability, and concurrent meniscal procedures, highlighting priorities for future research. Level of Evidence Level V, expert opinion.

Abstract Langerhans cell histiocytosis (LCH) is a rare histiocytic disorder infrequently complicated by delayed-onset pituitary disease. A 41-year-old female presented with papular, acneiform skin lesions. Shave biopsy demonstrated a superficial dermal epithelioid cell proliferation with S100, CD1a, and langerin positivity on immunohistochemistry and a BRAF p.N486_P490del inframe deletion-gain of function pathogenic variant on next-generation sequencing. The skin lesions spontaneously resolved. One year later, she developed progressive fatigue, fevers, anorexia, menstrual irregularities, polyuria, and polydipsia. Laboratory workup was consistent with panhypopituitarism. Pituitary magnetic resonance imaging noted mass-like thickening and enhancement of the infundibulum extending toward the hypothalamus. After treatment with cobimetinib, magnetic resonance imaging findings resolved but endocrinopathies persisted, requiring indefinite hormone therapy. This case demonstrates the full spectrum of endocrinopathies of LCH-induced pituitary disease and is an unusual circumstance of LCH with delayed-onset panhypopituitarism.

BACKGROUND: Small, randomized trials of patients with cervical artery dissection showed conflicting results regarding optimal stroke prevention strategies. We aimed to compare outcomes in patients with cervical artery dissection treated with antiplatelets versus anticoagulation. METHODS: This is a multicenter observational retrospective international study (16 countries, 63 sites) that included patients with cervical artery dissection without major trauma. The exposure was antithrombotic treatment type (anticoagulation versus antiplatelets), and outcomes were subsequent ischemic stroke and major hemorrhage (intracranial or extracranial hemorrhage). We used adjusted Cox regression with inverse probability of treatment weighting to determine associations between anticoagulation and study outcomes within 30 and 180 days. The main analysis used an as-treated crossover approach and only included outcomes occurring with the above treatments. RESULTS: The study included 3636 patients (402 [11.1%] received exclusively anticoagulation and 2453 [67.5%] received exclusively antiplatelets). By day 180, there were 162 new ischemic strokes (4.4%) and 28 major hemorrhages (0.8%); 87.0% of ischemic strokes occurred by day 30. In adjusted Cox regression with inverse probability of treatment weighting, compared with antiplatelet therapy, anticoagulation was associated with a nonsignificantly lower risk of subsequent ischemic stroke by day 30 (adjusted hazard ratio [HR], 0.71 [95% CI, 0.45–1.12]; P =0.145) and by day 180 (adjusted HR, 0.80 [95% CI, 0.28–2.24]; P =0.670). Anticoagulation therapy was not associated with a higher risk of major hemorrhage by day 30 (adjusted HR, 1.39 [95% CI, 0.35–5.45]; P =0.637) but was by day 180 (adjusted HR, 5.56 [95% CI, 1.53–20.13]; P =0.009). In interaction analyses, patients with occlusive dissection had significantly lower ischemic stroke risk with anticoagulation (adjusted HR, 0.40 [95% CI, 0.18–0.88]; P interaction =0.009). CONCLUSIONS: Our study does not rule out the benefit of anticoagulation in reducing ischemic stroke risk, particularly in patients with occlusive dissection. If anticoagulation is chosen, it seems reasonable to switch to antiplatelet therapy before 180 days to lower the risk of major bleeding. Large prospective studies are needed to validate our findings.

AimsCeramic-on-ceramic (CoC) articulations in total hip arthroplasty (THA) have the advantage of low wear but the unique risk of fracture. After revision for CoC-bearing fracture, third-body ceramic particles can lead to massive wear of cobalt-chrome (CoCr) bearings, causing extremely elevated blood cobalt. We present a multicentre series of five cases where patients sustained fractures of ceramic liners, were revised using a CoCr articulation, and rapidly developed severe cobalt toxicity.MethodsWe identified five cases of cobalt toxicity after fractured CoC THA treated with revision to CoCr on polyethylene bearings. Mean follow-up was three years (5 to 72 months) after re-revision to remove the CoCr bearing.ResultsSymptoms of cobalt toxicity occurred at a mean ten months (6 to 12) after revision for ceramic fracture. All patients developed vision and hearing loss, balance difficulties, and peripheral neuropathy. Several had cardiomyopathy, endocrine abnormalities, and local skin discolouration. Only two reported hip pain. Repeat revision for recognized cobalt toxicity occurred at a mean 22 months after revision for ceramic fracture. Mean serum cobalt level at re-revision was 991 ng/ml (normal value < 1 ng/ml; 734 to 1,302). All CoCr femoral heads exhibited massive wear, and deep tissues showed prominent metal staining. Treatment consisted of debridement and revision to a ceramic femoral head with highly cross-linked polyethylene (HXLPE) liner. Serum cobalt improved to a mean 25 μg/l (1 to 76) at final follow-up. All patients reported partial improvement in vision and hearing, however their peripheral neuropathy and balance difficulties did not recover.ConclusionSystemic cobalt toxicity is a devastating complication of ceramic-bearing fracture in THA treated with CoCr bearings, which may not present with hip symptoms. The diagnosis of this syndrome of systemic cobalt toxicity was significantly delayed following systemic symptoms in this series. Debridement and re-revision to a ceramic-on-HXLPE bearing leads to improvement, but not full resolution, of cobalt toxicity complications.Cite this article: Bone Joint J 2025;107-B(6 Supple B):92–100.