Acral melanoma is a dismal subtype of melanoma occurring in glabrous acral skin, and has a higher incidence in East Asians. We perform single-cell RNA sequencing for 63,394 cells obtained from 5 acral and 3 cutaneous melanoma samples to investigate tumor heterogeneity and immune environment. We define 5 orthogonal functional cell clusters that are involved in TGF-beta signaling, Type I interferon, Wnt signaling, Cell cycle, and Cholesterol efflux signaling. Signatures of enriched TGF-beta, Type I interferon, and cholesterol efflux signaling are significantly associated with good prognosis of melanoma. Compared with cutaneous melanoma, acral melanoma samples have significantly severe immunosuppressive state including depletion of cytotoxic CD8+ T cells, enrichment of Treg cells, and exhausted CD8+ T cells. PD1 and TIM-3 have higher expression in the exhaustive CD8+ T cells of acral melanoma. Key findings are verified in two independent validation sets. This study contributes to our better understanding of acral melanoma.

Spatial distancing of a substrate’s reactive group and nonreactive catalyst-binding group from its pro-stereogenic element presents substantial hurdles in asymmetric catalysis. In this context, we report a desymmetrizing Suzuki–Miyaura reaction that establishes chirality at a remote quaternary carbon. The anionic, chiral catalyst exerts stereocontrol through electrostatic steering of substrates, even as the substrate’s reactive group and charged catalyst-binding group become increasingly distanced. This study demonstrates that precise long-range stereocontrol is achievable by engaging ionic substrate–ligand interactions at a distal position.

Background: This study sought to assess the prognostic factors for leiomyosarcoma (LMS) patients with lung metastasis and construct web-based nomograms to predict overall survival (OS) and cancer-specific survival (CSS). Method: Patients diagnosed with LMS combined with lung metastasis between 2010 and 2016 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. The patients were randomly divided into a training set and a testing set. The X-tile analysis provides the best age and tumor size cut-off point, and changes continuous variables into categorical variables. The independent prognostic factors were determined by Cox regression analysis, and 2 nomograms were established. Receiver operating characteristic curves and calibration curves were used to evaluate the nomograms. Based on the nomograms, 2 web-based nomograms were established. Results: Two hundred and twenty-eight cases were included in the OS nomogram construction, and were randomly divided into a training set (n=160) and a validation set (n=68). Age, T stage, bone metastasis, surgery, chemotherapy, marital status, tumor size, and tumor site were found to be correlated with OS. One hundred and eighty-three cases were enrolled in the CSS nomogram construction, and randomly divided into a training set (n=129) and a validation set (n=54). Age, bone metastasis, surgery, chemotherapy, tumor size, and tumor site were found to be correlated with CSS. Two nomograms were established to predict OS and CSS. In the training set, the areas under the curve of the nomogram for predicting 1-, 2-, and 3-year OS were 0.783, 0.830, and 0.832, respectively, and those for predicting 1-, 2-, and 3-year CSS were 0.889, 0.777, and 0.884, respectively. Two web-based nomograms were established to predict OS (https://wenn23. shinyapps.io/lmslmosapp/), and CSS (https://wenn23.shinyapps.io/lmslmcssapp/). Conclusion:The developed web-based nomogram is a useful tool for accurately analyzing the prognosis of LMS patients with lung metastasis, and could help clinical doctors to make personalized clinical decisions.

The expression profile and specific roles of microRNAs (miRNAs) in regulation of atrophic bone nonunion are not fully understood. Here, we present evidence that miRNAs are involved in regulation of several osteogenic genes and may contribute to the development of atrophic bone nonunion. The miRNA expression profile of repairing tissues in atrophic bone nonunion patients (group A) and in callus tissues from patients with healed fractures (group B) were quantitatively measured. microRNA microarrays were used to identify differentially expressed miRNAs, and the bioinformatics methods were used to predict the potential target genes. Quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and dual-luciferase reporter assay were performed in human bone marrow stromal cells (hBMSCs) to validate the microarray results. Nine miRNAs in group A were up-regulated 1.5 times compared to group B, while the other 9 miRNAs in group A were down-regulated 1.5 times. Several target regions of these miRNAs were identified in the osteogenic genes, as well as in the other genes in their families or related regulatory factors. Four miRNAs (hsa-miR-149 ∗ , hsa-miR-221, hsa-miR-628-3p, and hsa-miR-654-5p) could play important roles in regulating bone nonunion development. hBMSCs transfected with these miRNAs significantly decreased mRNA levels of alkaline phosphatase, liver/bone/kidney ( ALPL ), platelet derived growth factor subunit A ( PDGFA ), and bone morphogenetic protein 2 ( BMP2 ). Lower protein expression levels were observed using western blotting, confirming that ALPL , PDGFA , and BMP2 were directly targeted by hsa-miR-149 ∗ , hsa-miR-221, and hsa-miR-654-5p, respectively. In summary, hsa-miR-149 ∗ , hsa-miR-221, and hsa-miR-654-5p may play important biological roles by repressing osteogenic target genes ALPL , PDGFA , and BMP2 , and, therefore, contributing to progression of atrophic bone nonunion.

Osteoporosis is a bone disease that has been connected with reactive oxygen species (ROS)-induced cytotoxicity. Mitochondrial dysfunction may be involved in the mechanism underlying ROS-induced cytotoxicity. It has been demonstrated that melatonin may exert cytoprotective effects by improving mitochondrial energetics and functions in several models of oxidative damage. In the present study, the MG63 osteoblast-like cell line was exposed to different concentrations of hydrogen peroxide (H2O2; 0, 100, 200, 400 or 800 µM) for 8 h, and 200 or 400 µM H2O2 for various periods of time (0.5, 4, 8 or 12 h). Results showed that H2O2 significantly reduced cell viability, increased the release of lactate dehydrogenase, increased the levels of ROS and malondialdehyde, reduced the concentration of adenosine-5'-triphosphate, disrupted the mitochondrial membrane potential (ΔΨm) and decreased the mitochondrial DNA copy number in MG63 cells. However, pretreatment with melatonin effectively decreased all of these H2O2-induced changes in cytotoxicity and mitochondrial dysfunction in MG63 cells. The protective effects of melatonin may be attributed to its ability to maintain mitochondrial function in H2O2-treated cells. This study suggests that melatonin is a potential pharmacological agent for preventing ROS-induced bone loss in diseases such as osteoporosis.