Osteosarcoma (OS) is a primary bone malignancy, and its progression can be hindered by inducing programmed cell death (PCD). Protein disulfide-isomerase (PDI) regulates cancer cell death; however, its functional role in OS remains unclear. P4HB expression was assessed in tumor tissues and cells from patients with OS using RT-qPCR. The effects of P4HB on OS cell lines were evaluated. Western blotting was used to assess the impact of P4HB on various forms of PCD (apoptosis, ferroptosis, and pyroptosis). Bioinformatics analysis identified the upstream and downstream mechanisms of P4HB in OS progression. A xenograft tumorigenesis study was performed to elucidate the role and mechanism of P4HB in OS progression. Elevated P4HB expression was observed in OS tissue samples and cell lines. Downregulation of P4HB suppressed OS cell growth, migration, and invasiveness and induced PCD. Functional enrichment analysis and experimental validation revealed that PDI upregulated vascular endothelial growth factor A (VEGFA) vascular endothelial growth factor receptor 2 (VEGFR2) signaling. Methylation analysis showed that the m6A demethylase fat mass and obesity-associated protein (FTO) decreased P4HB m6A levels and enhanced VEGFA-VEGFR2 signaling in OS cells. Moreover, FTO overexpression enhanced the proliferative, migratory, and invasive capabilities of OS cells and decreased PCD. Finally, FTO knockdown inhibited tumor growth and lung metastasis of OS by decreasing the activity of the PDI/VEGFA-VEGFR2 signaling axis. Mechanistically, FTO-mediated m6A modification of P4HB regulates PCD in OS through activation of this axis. © 2026 The Pathological Society of Great Britain and Ireland.

Strategies targeted vascular endothelial growth factor (VEGF)-dependent osteosarcoma progression are limited although important progress has been made in illustrating the mechanisms. Here we identified circ_001621 as one of the significantly upregulated circular RNAs (circRNAs) by circRNAs microarrays. We found that patients with high circ_001621 expression had a shorter survival time. Moreover, we found several potential sponge micro RNAs (miRNA) of circ_001621 with Circular RNA Interactome database. Among the candidate sponge, we elucidated the association of circ_001621 and miR-578. In addition, we demonstrated that miR-578 targeted circ_001621 directly. Functionally, we set up the experimental system to investigate the effects of circ_001621/miR-578/VEGF interaction in vitro and in vivo. Results indicated circ_001621-promoted osteosarcoma proliferation and migration via attenuating the inhibition of cyclin-dependent kinase 4 (CDK4) and matrix metallopeptidase 9 (MMP9) by miR-578, respectively. Nude mice experiment was further performed to estimate the promotion of metastasis by circ_001621. The present study evaluated the mechanisms underlying circ_001621 enhanced osteosarcoma progression and provided novel therapeutic targets for advanced osteosarcoma.

Background: A critical step in preoperative planning for revision knee arthroplasty is the identification of the failed implant. The purpose of this study was to develop and evaluate the performance of deep learning methods based on convolutional neural networks (CNN) to detect and identify specific knee arthroplasty models. Methods: In this study, we propose a novel deep learning-based approach to identify knee arthroplasty implants’ design using both anterior-posterior (AP) and lateral images. We harness the pre-trained ResNet50 CNN model and employ transfer learning methods to adapt the model for implants identification task using a total of 1814 radiographs of 8 different knee arthroplasty implant designs. Performance was compared with operative note and crosschecked with implant sheets. We also evaluate the difference of performance of models trained with AP images, lateral images or both. Results: The training and validation data sets were comprised of 907 AP and 907 lateral view radiographs across 733 patients and included 8 knee arthroplasty implants from 5 leading implant manufactures. After 1000 training epochs the model classified 8 implant models with very high accuracy. Our results showed that jointly using AP images and lateral images improved the classification accuracy of the CNN model. Conclusion: CNN can accurately distinguish between specific knee arthroplasty designs. This technology could offer a useful adjunct to the surgeon in preoperative identification of the prior implant. Furthermore, using both AP images and lateral images to train the CNN is more effective than using images from only one perspective.

Flexible electronics are highly developed nowadays in human-machine interfaces (HMI). However, challenges such as lack of flexibility, conductivity, and versatility always greatly hindered flexible electronics applications. In this work, a multifunctional hybrid hydrogel (H-hydrogel) was prepared by combining two kinds of 1D polymer chains (polyacrylamide and polydopamine) and two kinds of 2D nanosheets (Ti3C2Tx MXene and graphene oxide nanosheets) as quadruple crosslinkers. The introduced Ti3C2Tx MXene and graphene oxide nanosheets are bonded with the PAM and PDA polymer chains by hydrogen bonds. This unique crosslinking and stable structure endow the H-hydrogel with advantages such as good flexibility, electrical conductivity, self-adhesion, and mechanical robustness. The two kinds of nanosheets not only improved the mechanical strength and conductivity of the H-hydrogel, but also helped to form the double electric layers (DELs) between the nanosheets and the bulk-free water phase inside the H-hydrogel. When utilized as the electrode of a triboelectric nanogenerator (TENG), high electrical output performances were realized due to the dynamic balance of the DELs between the nanosheets and the H-hydrogel's inside water molecules. Moreover, flexible sensors, including triboelectric, and strain/pressure sensors, were achieved for human motion detection at low frequencies. This hydrogel is promising for HMI and e-skin.

目的:探究miR-196 在骨肉瘤和瘤旁组织中的表达差异,进而研究miR-196 在骨肉瘤MG-63细胞中对SMAD4 和上皮-间充质转化相关因子的调控作用及其对细胞侵袭能力的影响.方法:RT-qPCR检测 20 例患者的骨肉瘤和瘤旁组织中miR-196 的差异性表达,Targetscan和miRDB数据库寻找miR-196 序列与SMAD4 序列是否存在结合位点,Spearman相关系数分析miR-196 与SMAD4 的表达相关性,双荧光素酶报告基因实验验证miR-196 对SMAD4 的调控作用,RT-qPCR和Western blotting分别检测miR-196 与SMAD4 对上皮-间充质转化相关因子在RNA水平和蛋白质水平表达的调控关系,Tran-swell实验检测miR-196 对MG-63 细胞侵袭能力的影响.结果:骨肉瘤组织中miR-196 表达低于瘤旁组织,miR-196 和SMAD4 在骨肉瘤中的表达呈负相关(Y =-0.241 8∗X +1.188),过表达miR-196 可以在RNA水平和蛋白质水平抑制SMAD4、N-cadherin和Vimentin的表达并促进E-cadherin的表达,同时还能抑制骨肉瘤MG-63 细胞的侵袭能力.结论:miR-196 通过下调SMAD4 抑制上皮-间充质转化过程,发挥抑制骨肉瘤MG-63 细胞侵袭能力的作用.

N-6-methyladenosine (m6A) serves an essential role in RNA modulation and is implicated in multiple malignancies, including colorectal cancer (CRC). Methyltransferase-like 3 (METTL3) is an important writer in m6A modification, however its role in CRC in modifying small nucleolar RNA host gene 1 (SNHG1), an oncogenic long noncoding RNA, remains unclear. In the present study, METTL3 expression in CRC was assessed using online bioinformatics analysis, immunohistochemistry staining, western blotting, reverse transcription (RT)-quantitative PCR (qPCR) and cell transfections. Cell proliferation, migration and invasion were determined using functional Cell Counting Kit-8 (CCK-8) and Transwell assays. SNHG1 expression in CRC was evaluated using online bioinformatics analysis and RT-qPCR. Methylated RNA immunoprecipitation qPCR was performed to assess m6A modification changes of SNHG1 mRNA. The present study demonstrated that METTL3 is upregulated in CRC tissues and cell lines. Moreover, METTL3 expression was associated with several unfavourable clinical features in patients with CRC, including the stage of lymph node metastases and overall survival. Functional Transwell and CCK-8 assays demonstrated that knockdown of METTL3 suppressed CRC cell proliferation and migration. Furthermore, METTL3 was positively correlated with SNHG1 in CRC tissue, as indicated by analysis of data from The Cancer Genome Atlas. Mechanistically, SNHG1 contains 18 m6A modification sites. Through cell transfections and actinomycin D assays, the present study found that METTL3-mediated m6A modification at these sites enhances the stability of SNHG1 in CRC cells. Finally, it was demonstrated that SNHG1 knockdown partially diminished the facilitative effect of METTL3 on CRC cell migration and proliferation. The present study concluded that METTL3, a potential biomarker for assessing overall survival and metastasis in CRC, may serve as an oncogene, promote SNHG1 m6A modification, improve the stability of SNHG1 and enhance SNHG1-mediated oncogenic function in CRC.

Osteosarcoma, originating from primitive bone-forming mesenchymal cells, is the most common malignant bone tumour among children and adolescents. N6-methyladenosine (m6A), the most ubiquitous type of posttranscriptional modification, is a methylation that occurs in the N6-position of adenosine. m6A dramatically affects the splicing, export, translation, and stability of various RNAs, including mRNA and noncoding RNAs (ncRNAs). Increasing evidence suggests that ncRNAs, especially microRNAs (miRNA), long noncoding RNAs (lncRNA), and circular RNAs (circRNAs), regulate the m6A modification process by affecting the expression of m6A-associated enzymes. m6A modification interactions with ncRNAs provide new perspectives for exploring the underlying mechanisms of tumorigenesis and progression. In the current review, we summarized the expression and biological functions of m6A regulators in osteosarcoma. At the same time, the present review systematically elucidated the functional and mechanical interactions between m6A modification and ncRNAs in osteosarcoma. In addition, we discussed the effect of m6A and ncRNAs in the tumour microenvironment and potential clinical applications of osteosarcoma.

Osteosarcoma (OS) is a serve and the most frequent primary malignant tumor of bone. Chitosan was reported to have anti-tumor effect on human cancers including OS. However, the molecular mechanism by which chitosan suppresses tumor growth is not fully illustrated. In this study, human OS cell lines, including both Saos-2 and U2OS cells, were used to dissect the underlying mechanisms. RNA sequencing results show that a candidate biomarker family with sequence similarity 172 member A (FAM172A) was up-regulated in both of the two cell lines treated with chitosan. We observed that the mitogen-activated protein kinase (MAPK) signaling pathway could be inactivated by chitosan, and the MAPK inhibition caused by chitosan was reversed by FAM172A knockdown. Moreover, we uncovered a direct interaction between C-terminal domain of FAM172A (311-415) and mitogen-activated protein kinase kinase 1 (MEK1) (270-307) by immunoprecipitation assay. Finally, we also found that chitosan could bind with subunit p85 of PI3K to further inactivate the PI3K/Akt pathway. Taken together, our study demonstrates that chitosan binds with PI3K p85 subunit to suppress the activity of PI3K/Akt pathway to up-regulate the expression of FAM172A, and which exerts its function by suppressing phosphorylation of MEK1/2 and blocking the activity of MAPK/ERK signaling pathway. Taken together, our study deepens the understanding of the molecular mechanism of MAPK/ERK pathway inhibition induced by chitosan, and provides insights into the development of new targets to enhance the pharmacological effect of chitosan against OS.

目的 检测miR-196和CDK6在骨肉瘤组织中的表达情况,通过构建过表达和低表达miR-196的转染载体检测miR-196对CDK6表达的调控以及对骨肉瘤细胞增殖的影响.方法 通过生物信息学检测miR-196在骨肉瘤中的差异性表达,使用miRDB数据库寻找可能靶向CDK6的候选miRNA,采用RT-qPCR和Western blotting检测miR-196和CDK6表达之间的调控关系,MTT实验测定转染miR-196 mimic和miR-196 inhibitor的骨肉瘤细胞增殖活性,双荧光素酶报告实验检测miR-196在骨肉瘤细胞中对CDK6的调控作用.结果 骨肉瘤组织中miR-196表达下调1.773 993倍.构建过表达miR-196载体发现骨肉瘤细胞中CDK6的表达显著下调(P＜0.05).与此同时,miR-196的过表达能够使骨肉瘤细胞的增殖活性显著降低.结论 miR-196能够通过下调CDK6的表达来抑制骨肉瘤细胞的增殖.

N6-methyladenosine (m 6 A) modification, catalyzed by methyltransferase complexes (MTCs), plays many roles in multifaceted biological activities. As the most important subunit of MTCs, the METTL3-METTL14 complex is reported to be the initial factor that catalyzes the methylation of adenosines. Recently, accumulating evidence has indicated that the METTL3-METTL14 complex plays a key role in musculoskeletal diseases in an m 6 A-dependent or -independent manner. Although the functions of m 6 A modifications in a variety of musculoskeletal diseases have been widely recognized, the critical role of the METTL3-METTL14 complex in certain musculoskeletal disorders, such as osteoporosis, osteoarthritis, rheumatoid arthritis and osteosarcoma, has not been systematically revealed. In the current review, the structure, mechanisms and functions of the METTL3-METTL14 complex and the mechanisms and functions of its downstream pathways in the aforementioned musculoskeletal diseases are categorized and summarized.

First-line treatment for osteosarcoma includes chemotherapy and surgery. However, the five-year survival rate of refractory osteosarcoma remains unsatisfactory. Osteosarcoma cancer stem cells, possessing stemness and chemoresistance, are one of the critical causes of poor response to chemotherapy. Elucidating regulatory signaling pathways of osteosarcoma cancer stem cells may provide a rationale for improving regimens against chemoresistant osteosarcoma. Methotrexate (MTX)-resistant osteosarcoma cells were established. microRNA expression profiles were used for detecting differentially expressed microRNA in resistant clones and the parental cells. microRNA target databases were employed to predict potential microRNA and mRNA interactions. Flow cytometry was performed to measure stem cell marker Prominin-1 (CD133)-positive cells. Immunofluorescence staining was applied to detect CD133 expression. miR-197-3p mimic or anti-miR-197-3p stably transfected cells were used to generate xenograft models. In the study, we found that miR-197-3p was increased in MTX-resistant cell lines. Overexpression of miR-197-3p enhanced the expression of cancer stem cell markers CD133, Octamer-binding protein 4 (OCT4), Transcription factor SOX-2 (SOX2), and Homeobox protein NANOG (NANOG), as well as chemoresistance-associated genes ATP-dependent translocase ABCB1 (ABCB1) and Broad substrate specificity ATP-binding cassette transporter ABCG2 (ABCG2), whereas miR-197-3p knockdown inhibited stemness and recovered sensitivity to MTX. We also classified the tumor suppressor Speckle-type POZ protein-like (SPOPL) as a target of miR-197-3p. The miR-197-3p mutation that could not combine SPOPL promoter regions was unable to sustain stemness or chemoresistance. Collectively, we discovered miR-197-3p conferred osteosarcoma stemness and chemotherapy resistance by targeting SPOPL, prompting promising therapeutic candidates for refractory osteosarcoma treatment.

Data-intensive applications have achieved great success in the field of machine learning. How to ensure that the machine can still learn correctly in the absence of labeled samples is the next challenging problem to be solved. This paper first introduces the problem definition of few-shot learning. Secondly, the existing small few-shot learning methods based on meta-learning are comprehensively summarized. Specifically, they are divided into three categories: metric-based learning methods, optimization-based learning methods and model-based learning methods. We conducted a series of comparisons among various methods in each category to show the advantages and disadvantages of each method. Finally, the limitations of existing methods are analyzed, and the future development direction of few-shot learning research is prospected.

The localization of hazardous sources (e.g. poisonous gas sources) is an important task regarding the security of human society. To find the unknown source in time, various autonomous source searching methods have mushroomed and been employed over the past decade. This paper designs a fresh source searching approach, namely particle clustering-deep Q-network, PC-DQN, which applies the deep reinforcement learning (DRL) techniques as a source searching approach for the first time. Specifically, the search process is formulated as the partially observable Markov decision process, then converted into the Markov decision process based on the belief state (represented by the particle fil-ter). PC-DQN leverages the density-based spatial clustering of applications with noise (DBSCAN) algorithm to extract the feature of belief state, and employ the deep Q-network (DQN) algorithm to find the optimal policy for the source searching task. Through the comparison with two baseline methods (i.e. RANDOM and Entrotaxis algo-rithm) under various experimental conditions, the viability of our proposed PC-DQN is tes-tified. Results explicitly reveal that the success rate of the PC-DQN maintains at a high level (beyond 99.6%) in all scenarios in this paper, and the mean search step shows evident supe-riority over baseline methods in most scenarios. Significantly, we also introduce the trans-fer learning concept to reuse the well-trained Q-network into new scenarios. These findings show important implications of the DRL-based approach as an alternative and more effective source searching approach.(c) 2021 Elsevier Inc. All rights reserved.

The purpose of this study was to develop and evaluate the performance of deep learning methods based on convolutional neural networks (CNN) to detect and identify specific hip arthroplasty models. In this study, we propose a novel deep learning-based approach to identify hip arthroplasty implants' design using anterior-posterior images of both the stem and the cup. We harness the pre-trained ResNet50 CNN model and employ transfer learning methods to adapt the model for the implants identification task using a total of 714 radiographs of 4 different hip arthroplasty implant designs. Performance was compared with the operative notes and crosschecked with implant sheets. We also evaluate the difference in performance of models trained with the images of the stem, the cup or both. The training and validation data sets were comprised of 357 stem images and 357 cup radiographs across 313 patients and included 4 hip arthroplasty implants from 4 leading implant manufacturers. After 1000 training epochs the model classified 4 implant models with very high accuracy. Our results showed that jointly using stem images and cup images did not improve the classification accuracy of the CNN model. CNN can accurately distinguish between specific hip arthroplasty designs. This technology could offer a useful adjunct to the surgeon in preoperative identification of the prior implant. Using stem images or cup images to train the CNN can both achieve effective identification accuracy, with the accuracy of the stem images being higher. Using stem images and cup images together is not more effective than using images from only one perspective.

Osteoarthritis (OA) is a heterogeneous disease that is extremely hard to cure owing to its complex regulation network of pathogenesis, especially cartilage degeneration. FBXO21 is a subunit of ubiquitin E3 ligases that degrades P-glycoprotein and EID1 by ubiquitination and activates the JNK and p38 pathways; however, its role in OA remains unknown. Here, the main objective of this study was to evaluate the potential effects and mechanism of FBXO21 in OA degeneration, we revealed that FBXO21 is upregulated in the cartilage of patients with OA, aging, and monosodium iodoacetate-induced OA rats, and chondrocytes treated with interleukin-1β, tumor necrosis factor-α, and lipopolysaccharide. Moreover, the in vivo and in vitro knockdown of FBXO21 suppressed OA-related cartilage degeneration, as evidenced by activated autophagy, upregulated anabolism, alleviated apoptosis, and downregulated catabolism. In contrast, its overexpression promoted OA-related cartilage degeneration. In addition, using mass spectrometry and co-immunoprecipitation assay, we demonstrated that the downstream mechanism of FBXO21 inhibits autophagy by interacting with and phosphorylating ERK. Furthermore, FBXO21 alleviated anabolism and enhanced apoptosis and catabolism by inhibiting autophagy in rat chondrocytes. Interestingly, for its upstream mechanism, JUNB promoted FBXO21 expression by directly targeting the FBXO21 promoter, thus further accelerating cartilage degeneration in SW1353 cells and rat chondrocytes. Overall, our findings reveal that the JUNB-FBXO21-ERK axis regulates OA apoptosis and cartilage matrix metabolism by inhibiting autophagy. Therefore, FBXO21 is an attractive target for regulating OA pathogenesis, and its knockdown may provide a novel targeted therapy for OA.

Accumulating evidence has indicated that circular RNAs (circRNAs) serve crucial roles in the progression of a diverse range of different types of cancer, including osteosarcoma (OS). The present study determined the expression pattern and function of circRNA homeodomain interacting protein kinase 3 (circHIPK3), a novel circular RNA, in OS. It was revealed that circHIPK3 expression was upregulated in OS tissue samples and OS cell lines. A localization assay revealed that circHIPK3 was primarily located in the cytoplasm. Using loss-of-function proliferation and Transwell assays, the present study revealed that circHIPK3-knockdown suppressed OS cell proliferation, migration and invasion. Furthermore, the present study screened potential microRNAs that may interact with circHIPK3. It was revealed that microRNA-637 (miR-637) expression was downregulated in OS according to a Gene Expression Omnibus data analysis. In addition, the present study demonstrated that miR-637 expression was downregulated in OS cell lines. A fluorescence in situ hybridization assay revealed that both miR-637 and circHIPK3 were located in the cytoplasm. An in-depth mechanism investigation demonstrated that circHIPK3 expression was inversely correlated with miR-637 expression, and that circHIPK3 was a target of miR-637. In addition, it was revealed that histone deacetylase 4 (HDAC4) was another downstream target gene of miR-637, as demonstrated using a luciferase assay. It was revealed that miR-637 suppressed OS cell proliferation, migration and invasion via targeting of HDAC4. Finally, the present study demonstrated that circHIPK3 sponged miR-637 to promote HDAC4 expression and OS cell proliferation, migration and invasion. In conclusion, the present study uncovered the role of the circHIPK3/miR-637/HDAC4 axis in OS cell proliferation, migration and invasion. It was demonstrated that circHIPK3 promoted OS cell proliferation, migration and invasion by modulating miR-637/HDAC4 signaling.

There are several problems with traditional artificial skeletal age assessment methods, such as strong subjectivity, large random errors, complex assessment processes, and long assessment cycles. In this study, automated skeletal bone age assessment based on deep learning were performed. Other than examining all the bones in the whole hand, we have proposed a skeletal maturity assessment method based on the Standards of Skeletal Development of Hand and Wrist for Chinese (CHN) method that observing only 14 representative hand bones using the deep convolutional neural network (CNN). The method was compared with the traditional method using whole hand evaluated using the same test dataset. We have also expanded the dataset and increase the generalisation ability of the CNN using data augmentation. As a result, this method is able to improve the accuracy of the final skeletal age assessment and reduce the upper limit of the absolute value of the single skeletal age error. The experiments demonstrate the effectiveness of the proposed method, which can provide physicians with more stable, efficient, and convenient diagnostic assistance and decision support.

Osteoarthritis (OA) is a heterogeneous disease that is consistently difficult to treat due to the complexity of the regulatory network involved in OA pathogenesis, especially in terms of cartilage degeneration. As a C-2 epimer of glucose, d-mannose can alleviate bone loss and repress immunopathology by upregulating regulatory T cells; however, the role of d-mannose in OA-related cartilage degeneration remains unknown. In this study, we investigated the chondroprotective effect of d-mannose in vitro and in vivo on OA. We found that incubating interleukin (IL)-1β-treated rat chondrocytes with d-mannose restrained OA degeneration by elevating cell proliferation, strongly activating autophagy, reducing apoptosis, and downregulating catabolism. Additionally, oral gavage administration of d-mannose to monosodium iodoacetate (MIA)-treated rats revealed that a median (1.25 g/kg/day) rather than high or low dose of d-mannose suppressed OA progression and attenuated OA development based on lower macroscopic scores for cartilage, decreased histological scores for cartilage and synovium, strongly activated autophagy, and downregulated catabolism. In terms of a downstream mechanism, we showed that d-mannose might attenuate OA degeneration by activating autophagy in IL-1β-treated rat chondrocytes by promoting the phosphorylation of 5′ AMP-activated protein kinase (AMPK). Our in vitro findings revealed that d-mannose delayed IL-1β-induced OA degeneration in rat chondrocytes by enhancing autophagy activation through the AMPK pathway. Furthermore, the in vivo results indicated that a median dose of d-mannose suppressed MIA-induced OA development. These results suggested that d-mannose exhibits chondroprotective effects and represents a potential disease-modifying drug and novel therapeutic agent for OA.