DDT-RELATED PROTEIN4-IMITATION SWITCH alters nucleosome distribution to relieve transcriptional silencing in Arabidopsis.

DNA methylation is a conserved epigenetic modification that is typically associated with silencing of transposable elements and promoter methylated genes. However, some DNA-methylated loci are protected from silencing, allowing transcriptional flexibility in response to environmental and developmental cues. Through a genetic screen in Arabidopsis (Arabidopsis thaliana), we uncovered an antagonistic relationship between the MICRORCHIDIA (MORC) protein and the IMITATION SWITCH (ISWI) complex in regulating the DNA-methylated SUPPRESSOR OF DRM1 DRM2 CMT3 (SDC) reporter. We demonstrate that components of the plant-specific ISWI complex, including CHROMATIN REMODELING PROTEIN11 (CHR11), CHR17, DDT-RELATED PROTEIN4 (DDR4), and DDR5, function to partially derepress silenced genes and transposable elements (TEs), through their function in regulating nucleosome distribution. This action also requires the known transcriptional activator DNAJ proteins, providing a mechanistic link between nucleosome remodeling and transcriptional activation. Genome-wide studies revealed that DDR4 causes changes in nucleosome distribution at numerous loci, a subset of which is associated with changes in DNA methylation and/or transcription. Our work reveals a mechanism for balancing transcriptional flexibility and faithful silencing of DNA-methylated loci. As both ISWI and MORC family genes are widely distributed across plant and animal species, our findings may represent a conserved eukaryotic mechanism for fine-tuning gene expression under epigenetic regulation.

The roles of epigenetic regulators in plant regeneration: Exploring patterns amidst complex conditions.

Plants possess remarkable capability to regenerate upon tissue damage or optimal environmental stimuli. This ability not only serves as a crucial strategy for immobile plants to survive through harsh environments, but also made numerous modern plant improvements techniques possible. At the cellular level, this biological process involves dynamic changes in gene expression that redirect cell fate transitions. It is increasingly recognized that chromatin epigenetic modifications, both activating and repressive, intricately interact to regulate this process. Moreover, the outcomes of epigenetic regulation on regeneration are influenced by factors such as the differences in regenerative plant species and donor tissue types, as well as the concentration and timing of hormone treatments. In this review, we focus on several well-characterized epigenetic modifications and their regulatory roles in the expression of widely studied morphogenic regulators, aiming to enhance our understanding of the mechanisms by which epigenetic modifications govern plant regeneration.

The role of ATXR6 expression in modulating genome stability and transposable element repression in Arabidopsis.

ARABIDOPSIS TRITHORAX-RELATED PROTEIN 5 (ATXR5) AND ATXR6 are required for the deposition of H3K27me1 and for maintaining genomic stability in Arabidopsis Reduction of ATXR5/6 activity results in activation of DNA damage response genes, along with tissue-specific derepression of transposable elements (TEs), chromocenter decompaction, and genomic instability characterized by accumulation of excess DNA from heterochromatin. How loss of ATXR5/6 and H3K27me1 leads to these phenotypes remains unclear. Here we provide extensive characterization of the atxr5/6 hypomorphic mutant by comprehensively examining gene expression and epigenetic changes in the mutant. We found that the tissue-specific phenotypes of TE derepression and excessive DNA in this atxr5/6 mutant correlated with residual ATXR6 expression from the hypomorphic ATXR6 allele. However, up-regulation of DNA damage genes occurred regardless of ATXR6 levels and thus appears to be a separable process. We also isolated an atxr6-null allele which showed that ATXR5 and ATXR6 are required for female germline development. Finally, we characterize three previously reported suppressors of the hypomorphic atxr5/6 mutant and show that these rescue atxr5/6 via distinct mechanisms, two of which involve increasing H3K27me1 levels.

Resistance-gene-directed discovery of a natural-product herbicide with a new mode of action.

Bioactive natural products have evolved to inhibit specific cellular targets and have served as lead molecules for health and agricultural applications for the past century1-3. The post-genomics era has brought a renaissance in the discovery of natural products using synthetic-biology tools4-6. However, compared to traditional bioactivity-guided approaches, genome mining of natural products with specific and potent biological activities remains challenging4. Here we present the discovery and validation of a potent herbicide that targets a critical metabolic enzyme that is required for plant survival. Our approach is based on the co-clustering of a self-resistance gene in the natural-product biosynthesis gene cluster7-9, which provides insight into the potential biological activity of the encoded compound. We targeted dihydroxy-acid dehydratase in the branched-chain amino acid biosynthetic pathway in plants; the last step in this pathway is often targeted for herbicide development10. We show that the fungal sesquiterpenoid aspterric acid, which was discovered using the method described above, is a sub-micromolar inhibitor of dihydroxy-acid dehydratase that is effective as a herbicide in spray applications. The self-resistance gene astD was validated to be insensitive to aspterric acid and was deployed as a transgene in the establishment of plants that are resistant to aspterric acid. This herbicide-resistance gene combination complements the urgent ongoing efforts to overcome weed resistance11. Our discovery demonstrates the potential of using a resistance-gene-directed approach in the discovery of bioactive natural products.

Dual-mode vortex beam transmission metasurface antenna based on linear-to-circular polarization converter.

The generation of multi-mode vortex beams at the same aperture is currently emerging as a research hotspot. In this paper, a method based on a linearly polarized-circularly polarized translational transmission metasurface (TM) is proposed to enable a dual-circularly polarized dual-mode vortex beam generation. Through the judicious implementation of an additional rotational phase and the combination of the initial transmission phase, the phases of the left-hand circularly polarized (LHCP) and right-hand circularly polarized (RHCP) waves can be manipulated arbitrarily and independently. Meanwhile, the design of the array phase is utilized for the dual-mode dual-circularly polarized beam generation. Simulation and sample measurements provide validation data for the feasibility of this method, in which the measurement results are in excellent consistency with the simulation ones. This proposed method paves the way toward the enhancement of the channel capacity of mobile communication.

Genome mining and biosynthesis of a polyketide from a biofertilizer fungus that can facilitate reductive iron assimilation in plant.

Fungi have the potential to produce a large repertoire of bioactive molecules, many of which can affect the growth and development of plants. Genomic survey of sequenced biofertilizer fungi showed many secondary metabolite gene clusters are anchored by iterative polyketide synthases (IPKSs), which are multidomain enzymes noted for generating diverse small molecules. Focusing on the biofertilizer Trichoderma harzianum t-22, we identified and characterized a cryptic IPKS-containing cluster that synthesizes tricholignan A, a redox-active ortho-hydroquinone. Tricholignan A is shown to reduce Fe(III) and may play a role in promoting plant growth under iron-deficient conditions. The construction of tricholignan by a pair of collaborating IPKSs was investigated using heterologous reconstitution and biochemical studies. A regioselective methylation step is shown to be a key step in formation of the ortho-hydroquinone. The responsible methyltransferase (MT) is fused with an N-terminal pseudo-acyl carrier protein (ψACP), in which the apo state of the ACP is essential for methylation of the growing polyketide chain. The ψACP is proposed to bind to the IPKS and enable the trans MT to access the growing polyketide. Our studies show that a genome-driven approach to discovering bioactive natural products from biofertilizer fungi can lead to unique compounds and biosynthetic knowledge.

Long-term results of trans-scaphoid perilunate fracture dislocations treated by open reduction and internal fixation.

PURPOSE: The paper holds the research purpose of confirming the long-term results of trans-scaphoid perilunate fracture dislocations (TSPFD) under the treatment of open reduction and internal fixation. METHODS: Anteroposterial-lateral radiographs of the patient's wrist were taken before and after surgery. We use a dorsal approach for all cases. Postoperative clinical and radiographic assessments were performed routinely. The scapholunate angle (SLA), estradiol angle (RLA), as well as lunotriquetral distance (LTD) assisted in the radiographic assessment. Clinical assessment was performed using the Krimmer score, modified Mayo wrist score (MWS), active flexion extension arc (FEA), radial deviation and ulnar deviation arc (RUDA) and grip strength. A visual analog scale (VAS) assisted in the pain evaluation, the VAS score ranges from 0 to 10. RESULTS: Twenty-two TSPFD patients due to the wrist trauma received operative treatment and we retrospectively analyzed the surgical results, together with evaluating their clinical and radiological follow-up. These patients held a mean age of 30 years old. Herzberg's perilunate fracture-dislocation classification was taken into account to find that 19 males and 3 females suffered dorsal dislocation. The fellow-up time lasted 98.3 months on average. All cases obtained sufficient union after open reduction and internal fixation. The last follow-up found the median of grip strength was 20.00 (interquartile range, 20.00-21.25), which was 84.5% of the normal side. The modified Mayo wrist score evaluation scale considered 12 cases as excellent, and 10 good. The median of VAS and Krimmer scores at the final follow-up were 1.50 (interquartile range, 0.75-2.00) and 100.00 (interquartile range, 100.00-100.00), respectively, higher relative to the pre-operation (P < 0.001). No patients showed nerve damage preoperatively or postoperatively, or pin tract infection in any of the patient. CONCLUSIONS: It is necessary to diagnose such complicated biomechanical damage in early stage and adopt the open reduction and stable fixation for treatment; appropriate treatment can contribute to a functionally adequate and anatomically integrated wrist.

Oncologic and functional outcomes of different reconstruction modalities after resection of chondrosarcoma of the scapula: a medium- to long-term follow-up study.

OBJECTIVES: To evaluate the oncologic and functional results of scapular reconstruction after partial or total scapulectomy for chondrosarcoma. MATERIALS AND METHODS: Twenty-one patients with chondrosarcoma who underwent partial or total scapulectomy between January 2005 and July 2019 were reviewed retrospectively. RESULTS: At a mean follow-up of 62.6 months (range, 13-123 months), four patients developed local recurrence, and three developed distant metastases, one of which developed both recurrence and metastasis. The overall survival rate of patients at 5 years was 84.6%, the disease-free survival rate was 69.3%, and the complication rate was 19% (4/21). The 1993 American Musculoskeletal Tumor Society (MSTS93) scores of patients in the partial scapulectomy group, total scapulectomy + humeral suspension group and prosthetic reconstruction group were 26.50 ± 1.38, 19.00 ± 2.58, and 21.38 ± 2.62, respectively. There was a statistically significant difference between the partial scapulectomy group and the total scapulectomy + humeral suspension or prosthetic reconstruction group ( P = 0.006 and 0.0336, respectively). The range of motion of the shoulder joint for forward flexion was 80.83° ± 11.14°, 51.25° ± 21.36°, and 52.50° ± 11.02°, respectively. The p-values for the comparison between the partial scapulectomy group and the total scapulectomy + humeral suspension or prosthetic reconstruction group were 0.0493 and 0.0174, respectively. And the range of motion of abduction was 75.00° ± 10.49°, 32.50° ± 11.90°, 41.88° ± 11.63°, respectively. Patients in the partial scapulectomy group had significantly better postoperative shoulder abduction function than the total scapulectomy + humeral suspension or prosthetic reconstruction group (P = 0.0035 and 0.0304, respectively). There was no significant difference in MSTS93 scores and flexion and abduction function of the shoulder joint in the upper extremity after total scapulectomy with humeral suspension or prosthetic reconstruction (P > 0.05). CONCLUSIONS: Surgical treatment of chondrosarcoma of the scapula can achieve a satisfactory prognosis and shoulder function. Total scapulectomy followed by prosthetic reconstruction or humeral suspension are both feasible treatments.

Large-scale comparative epigenomics reveals hierarchical regulation of non-CG methylation in Arabidopsis.

Genome-wide characterization by next-generation sequencing has greatly improved our understanding of the landscape of epigenetic modifications. Since 2008, whole-genome bisulfite sequencing (WGBS) has become the gold standard for DNA methylation analysis, and a tremendous amount of WGBS data has been generated by the research community. However, the systematic comparison of DNA methylation profiles to identify regulatory mechanisms has yet to be fully explored. Here we reprocessed the raw data of over 500 publicly available Arabidopsis WGBS libraries from various mutant backgrounds, tissue types, and stress treatments and also filtered them based on sequencing depth and efficiency of bisulfite conversion. This enabled us to identify high-confidence differentially methylated regions (hcDMRs) by comparing each test library to over 50 high-quality wild-type controls. We developed statistical and quantitative measurements to analyze the overlapping of DMRs and to cluster libraries based on their effect on DNA methylation. In addition to confirming existing relationships, we revealed unanticipated connections between well-known genes. For instance, MET1 and CMT3 were found to be required for the maintenance of asymmetric CHH methylation at nonoverlapping regions of CMT2 targeted heterochromatin. Our comparative methylome approach has established a framework for extracting biological insights via large-scale comparison of methylomes and can also be adopted for other genomics datasets.

Comprehensive Annotation of Physcomitrella patens Small RNA Loci Reveals That the Heterochromatic Short Interfering RNA Pathway Is Largely Conserved in Land Plants.

Many plant small RNAs are sequence-specific negative regulators of target mRNAs and/or chromatin. In angiosperms, the two most abundant endogenous small RNA populations are usually 21-nucleotide microRNAs (miRNAs) and 24-nucleotide heterochromatic short interfering RNAs (siRNAs). Heterochromatic siRNAs are derived from repetitive regions and reinforce DNA methylation at targeted loci. The existence and extent of heterochromatic siRNAs in other land plant lineages has been unclear. Using small RNA-sequencing (RNA-seq) of the moss Physcomitrella patens, we identified 1090 loci that produce mostly 23- to 24-nucleotide siRNAs. These loci are mostly in intergenic regions with dense DNA methylation. Accumulation of siRNAs from these loci depends upon P. patens homologs of DICER-LIKE3 (DCL3), RNA-DEPENDENT RNA POLYMERASE2, and the largest subunit of DNA-DEPENDENT RNA POLYMERASE IV, with the largest subunit of a Pol V homolog contributing to expression at a smaller subset of the loci. A MINIMAL DICER-LIKE (mDCL) gene, which lacks the N-terminal helicase domain typical of DCL proteins, is specifically required for 23-nucleotide siRNA accumulation. We conclude that heterochromatic siRNAs, and their biogenesis pathways, are largely identical between angiosperms and P. patens, with the notable exception of the P. patens-specific use of mDCL to produce 23-nucleotide siRNAs.

Analysis of complementarity requirements for plant microRNA targeting using a Nicotiana benthamiana quantitative transient assay.

MicroRNAs (miRNAs) guide RNA-induced silencing complexes to target RNAs based on miRNA-target complementarity. Using a dual-luciferase based sensor system in Nicotiana benthamiana, we quantitatively assessed the relationship between miRNA-target complementarity and silencing efficacy measured at both the RNA and protein levels, using several conserved miRNAs and their known target sites from Arabidopsis thaliana. We found that naturally occurring sites have variable efficacies attributable to their complementarity patterns. We also observed that sites with a few mismatches to the miRNA 3' regions, which are common in plants, are often equally effective and sometimes more effective than perfectly matched sites. By contrast, mismatches to the miRNA 5' regions strongly reduce or eliminate repression efficacy but are nonetheless present in several natural sites, suggesting that in some cases, suboptimal miRNA efficacies are either tolerated or perhaps selected for. Central mismatches fully abolished repression efficacy in our system, but such sites then became effective miRNA target mimics. Complementarity patterns that are functional in animals (seed sites, 3'-supplementary sites, and centered sites) did not reliably confer repression, regardless of context (3'-untranslated region or open reading frame) or measurement type (RNA or protein levels). Overall, these data provide a robust and empirical foundation for understanding, predicting, and designing functional miRNA target sites in plants.

A non-canonical plant microRNA target site.

Plant microRNAs (miRNAs) typically form near-perfect duplexes with their targets and mediate mRNA cleavage. Here, we describe an unconventional miRNA target of miR398 in Arabidopsis, an mRNA encoding the blue copper-binding protein (BCBP). BCBP mRNA carries an miR398 complementary site in its 5'-untranslated region (UTR) with a bulge of six nucleotides opposite to the 5' region of the miRNA. Despite the disruption of a target site region thought to be especially critical for function, BCBP mRNAs are cleaved by ARGONAUTE1 between nucleotides 10th and 11th, opposite to the miRNA, like conventional plant target sites. Levels of BCBP mRNAs are inversely correlated to levels of miR398 in mutants lacking the miRNA, or transgenic plants overexpressing it. Introducing two mutations that disrupt the miRNA complementarity around the cleavage site renders the target cleavage-resistant. The BCBP site functions outside of the context of the BCBP mRNA and does not depend on 5'-UTR location. Reducing the bulge does not interfere with miR398-mediated regulation and completely removing it increases the efficiency of the slicing. Analysis of degradome data and target predictions revealed that the miR398-BCBP interaction seems to be rather unique. Nevertheless, our results imply that functional target sites with non-perfect pairings in the 5' region of an ancient conserved miRNA exist in plants.

Successful treatment of epidermodysplasia verruciformis with a combination of 5-aminolevulinic acid photodynamic therapy and surgery.

Epidermodysplasia verruciformis (EV) is a rare inherited immune disease characterized by pityriasis versicolor-like macules, hyperpigmented or hypopigmented warty papules and irregular reddish-brown plaques, mainly on the face, neck and extremities. Some therapeutic options include medications, lifestyle changes, ALA-PDT, surgery and so on. But there is no cure for EV and thus the clinical management is challenging. We report a case of EV that was refractory to multiple therapies and achieved an encouraging result with a combination therapy of surgery and 5-aminolevulinic acid photodynamic therapy (ALA-PDT).

Genetic and epigenetic signatures for improved breeding of cultivated blueberry.

Blueberry belongs to the Vaccinium genus and is a highly popular fruit crop with significant economic importance. It was not until the early twentieth century that they began to be domesticated through extensive interspecific hybridization. Here, we collected 220 Vaccinium accessions from various geographical locations, including 154 from the United States, 14 from China, eight from Australia, and 29 from Europe and other countries, comprising 164 Vaccinium corymbosum, 15 Vaccinium ashei, 10 lowbush blueberries, seven half-high blueberries, and others. We present the whole-genome variation map of 220 accessions and reconstructed the hundred-year molecular history of interspecific hybridization of blueberry. We focused on the two major blueberry subgroups, the northern highbush blueberry (NHB) and southern highbush blueberry (SHB) and identified candidate genes that contribute to their distinct traits in climate adaptability and fruit quality. Our analysis unveiled the role of gene introgression from Vaccinium darrowii and V. ashei into SHB in driving the differentiation between SHB and NHB, potentially facilitating SHB's adaptation to subtropical environments. Assisted by genome-wide association studies, our analysis suggested VcTBL44 as a pivotal gene regulator governing fruit firmness in SHB. Additionally, we conducted whole-genome bisulfite sequencing on nine NHB and 12 SHB cultivars, and characterized regions that are differentially methylated between the two subgroups. In particular, we discovered that the ß-alanine metabolic pathway genes were enriched for DNA methylation changes. Our study provides high-quality genetic and epigenetic variation maps for blueberry, which offer valuable insights and resources for future blueberry breeding.

An inducible CRISPR activation tool for accelerating plant regeneration.

The inducible CRISPR activation (CRISPR-a) system offers unparalleled precision and versatility for regulating endogenous genes, making it highly sought after in plant research. In this study, we developed a chemically inducible CRISPR-a tool for plants called ER-Tag by combining the LexA-VP16-ER inducible system with the SunTag CRISPR-a system. We systematically compared different induction strategies and achieved high efficiency in target gene activation. We demonstrated that guide RNAs can be multiplexed and pooled for large-scale screening of effective morphogenic genes and gene pairs involved in plant regeneration. Further experiments showed that induced activation of these morphogenic genes can accelerate regeneration and improve regeneration efficiency in both eudicot and monocot plants, including alfalfa, woodland strawberry, and sheepgrass. Our study expands the CRISPR toolset in plants and provides a powerful new strategy for studying gene function when constitutive expression is not feasible or ideal.

Dumbbell-type tenosynovial giant cell tumor of the buttocks: a report of two cases.

Background: Tenosynovial giant cell tumor (TSGCT) is a benign tumor derived from the synovium of the joints, bursa, and tendon sheaths, which is mainly located around the tendon sheath of hand and foot. Extra-articular TSGCT are relatively rare and are mainly found in the soft tissue around the large joint. They are rarer when located purely intramuscular or subcutaneous, and mostly in the lower extremities. Case Description: We report two rare cases of completely extra-articular TSGCT located at the buttocks. One case was a 23-year-old young male presenting with left buttock swelling and pain for 1 year. Magnetic resonance imaging (MRI) examination revealed a dumbbell-type cystic solid mass in the left buttock, growing anteriorly from the deep surface of the gluteus muscle along the medial of the lesser trochanter. The lesion showed a heterogeneous mixed signal and was well-defined. MRI presentation needs to be differentiated with neurogenic or mesenchymal tumors, and radical resection of left gluteal tumor + neurovascular exploration surgery was performed. Another case of TSGCT we present here was diagnosed in a 55-year-old male elderly patient. Computed tomography angiography (CTA) revealed an irregular soft tissue mass in the left buttock involving the sacroiliac joint. T1-weighted imaging (T1WI) on MRI showed a mixed signal with predominantly isosignal, well-defined, and seemingly enveloped. A left buttock tumor resection with the scraping of the sacroiliac joint lesion was performed. Conclusions: Based on histopathological examination, the diagnosis was diffuse-type TSGCT for both cases. Both patients were periodically monitored after surgery, and one of them showed no imaging findings of recurrence or metastases seven years after surgery; the other case showed recurrence one year after surgery, which was resected and treated with radiotherapy, and there has been no recurrence so far. TSGCT occurring completely intramuscular is rare, with atypical clinical symptoms and imaging presentation, requiring differentiation with mesenchymal and giant cell-rich tumors.

circ_0072464 Shuttled by Bone Mesenchymal Stem Cell-Secreted Extracellular Vesicles Inhibits Nucleus Pulposus Cell Ferroptosis to Relieve Intervertebral Disc Degeneration.

Ferroptosis, as an iron-dependent form of necrotic cell death, has been reported to affect activities of nucleus pulposus cells (NPCs). However, its role in the pathogenesis of intervertebral disc degeneration (IDD) is largely unknown. Notably, our bioinformatics analysis predicted that circ_0072464 was downregulated in nucleus pulposus of IDD mice. Therefore, this study is aimed at clarifying the mechanisms of extracellular vesicle- (EV-) encapsulated circ_0072464 derived from bone marrow mesenchymal stem cells (BMSCs) in NPC ferroptosis in IDD. EVs were extracted from mouse BMSCs (BMSC-EVs) and then cocultured with IL-1ß-induced NPCs, followed by detection of matrix synthesis, proliferation, and ferroptosis of NPCs based on gain- or loss-of-function experiments. It was found that the uptake of BMSC-EVs by NPCs alleviated IDD. circ_0072464 and NRF2 were downregulated, and miR-431 was upregulated in IDD. Mechanistically, circ_0072464 competitively bound to miR-431, which targeted and inhibited NRF2 expression. BMSC-derived EVs carrying circ_0072464 inhibited NPC ferroptosis to promote matrix synthesis and proliferation of NPCs by inhibiting miR-431 and upregulating NRF2. Besides, in vivo experiments also confirmed that BMSC-EVs alleviated intervertebral disc lesions in mice with IDD through the circ_0072464/miR-431/NRF2 axis. Collectively, BMSC-EV-loaded circ_0072464 inhibited NPC ferroptosis to relieve IDD via upregulation of miR-431-mediated NRF2, therefore providing a potential therapeutic target against IDD.

Risk factors for lymph node metastasis of soft tissue sarcomas of the head, neck, and extremities, and the clinical significance of negative lymph node dissection.

BACKGROUND: This study sought to define the risk factors for lymph node metastasis (LNM) of soft tissue sarcomas (STS) of the head, neck, and extremities, and the clinical significance of negative lymph node dissection (NLND). METHODS: STS patient data in the Surveillance, Epidemiology, and End Results (SEER) database from 1988 to 2015 were extracted and pooled. Logistics regression analysis was used to identify risk factors for LNM, Cox proportional hazards and Fine-Grey's models were used for survival analysis, and Propensity score matching analysis (PSM) was used to assess the impact of NLND on patient prognosis. RESULTS: A total of 3276 patients were enrolled in the study, of whom 283 (8.6%) developed LNM. Rhabdomyosarcoma had the highest rate of LNM (25.3%), followed by clear cell sarcoma (16.8%) and epithelioid sarcoma (12.4%), while leiomyosarcoma had the lowest rate of LNM (1.3%). Sex, tumor size, grade, histology, and site were significantly associated with LNM. For specific histologic subtypes of STS, NLND significantly improves overall survival (HR: 0.718, 95%CI 0.535-0.962; P = 0.026) and cancer-specific survival (HR: 0.699, 95%CI 0.506-0.967; P = 0.031) and reduces cancer-specific mortality (Gray's test, P = 0.017). However, NLND did not improve overall survival (P = 0.46) or reduce cancer-specific mortality (Gray's test, P = 0.772) of patients with leiomyosarcoma. CONCLUSIONS: Histology is an independent risk factor for LNM in STS of the head, neck, and extremities. Prophylactic NLND treatment was necessary and had a clinical benefit for patients with STS who were at high risk for LNM but had no significant impact on the prognosis of patients with leiomyosarcoma.