Inhibition of anlotinib-induced autophagy attenuates invasion and migration by regulating epithelial-mesenchymal transition and cytoskeletal rearrangement through ATG5 in human osteosarcoma cells

Abstract The cure rates for osteosarcoma have remained unchanged in the past three decades, especially for patients with pulmonary metastasis. Thus, a new and effective treatment for metastatic osteosarcoma is urgently needed. Anlotinib has been reported to have antitumor effects on advanced osteosarcoma. However, both the effect of anlotinib on autophagy in osteosarcoma and the mechanism of anlotinib-mediated autophagy in pulmonary metastasis are unclear. The effect of anlotinib treatment on the metastasis of osteosarcoma was investigated by transwell assays, wound healing assays, and animal experiments. Related proteins were detected by western blotting after anlotinib treatment, ATG5 silencing, or ATG5 overexpression. Immunofluorescence staining and transmission electron microscopy were used to detect alterations in autophagy and the cytoskeleton. Anlotinib inhibited the migration and invasion of osteosarcoma cells but promoted autophagy and increased ATG5 expression. Furthermore, the decreases in invasion and migration induced by anlotinib treatment were enhanced by ATG5 silencing. In addition, Y-27632 inhibited cytoskeletal rearrangement, which was rescued by ATG5 overexpression. ATG5 overexpression enhanced epithelial-mesenchymal transition (EMT). Mechanistically, anlotinib-induced autophagy promoted migration and invasion by activating EMT and cytoskeletal rearrangement through ATG5 both in vitro and in vivo. Our results demonstrated that anlotinib can induce protective autophagy in osteosarcoma cells and that inhibition of anlotinib-induced autophagy enhanced the inhibitory effects of anlotinib on osteosarcoma metastasis. Thus, the therapeutic effect of anlotinib treatment can be improved by combination treatment with autophagy inhibitors, which provides a new direction for the treatment of metastatic osteosarcoma.

Effect and mechanism of berberine-induced ferroptosis in osteosarcoma cells / 中国药房

OBJECTIVE To investigate the effect of berberine on ferroptosis in MG63 osteosarcoma cells and its mechanism. METHODS Using cells without drug treatment as control， the cell viability， proliferation， the related indexes of ferroptosis [nuclear proliferation associated-antigen （Ki67）， mitochondrial ultrastructure， ferric ion （Fe2+）， reactive oxygen species （ROS）， malondialdehyde （MDA）， and glutathione （GSH）]， the protein expression of signal transducer and activator of transcription 3 （STAT3）， tumor protein 53 （p53）， and solute carrier family 7 member 11 （SLC7A11） were detected after being treated with different concentrations of berberine. Cells were transfected with p53 siRNA and then assigned to the control group， p53 siRNA group， berberine group， and p53 siRNA+berberine group to explore the role of p53 in berberine-induced ferroptosis. After 24 h incubation with 10.0 μmol/L berberine， the protein expressions of p53 and SLC7A11， the levels of mitochondrial membrane potential， GSH， and MDA content were determined. Cells were transfected with STAT3 overexpressed plasmid and then assigned to the control group， berberine group， STAT3 group， and STAT3+berberine group to explore the effect of STAT3 on the regulation of the p53/SLC7A11 pathway. After 24 h incubation with 10 μmol/L berberine， the protein expressions of p-STAT3， STAT3， p53， and SLC7A11 were detected. RESULTS Compared with the control cell， the concentrations of 2.5， 5.0 and 10.0 μmol/L berberine could reduce the cell viability and expression of Ki67， and induce the morphological changes in ferroptosis-related mitochondria， increase the levels of Fe2+， ROS and MDA， and the protein expression of p53， reduce the level of GSH， the binding activity of STAT3 with DNA， and the protein expressions of p-STAT3 and SLC7A11； the above differences were statistically significant （P＜ 0.05 or P＜0.01）. Compared with the berberine group，significantly down-regulated p53 protein expression and MDA level， up-regulated SLC7A11 protein expression， and increased mitochondrial membrane potential and GSH level were observed in the p53 siRNA+berberine group （P＜0.01）. Compared with the berberine group， the protein expressions of p-STAT3， STAT3， and SLC7A11 in the STAT3+berberine group were significantly increased （P＜0.01）， while the protein expression of p53 was significantly decreased （P＜0.01）. CONCLUSIONS Berberine can induce the ferroptosis of MG63 cells by mediating STAT3/p53/SLC7A11 signaling pathway.

Mechanism of oxymatrine promoting the apoptosis of osteosarcoma MG63 cell line through mitophagy mediated by COX-2/PINK1/Parkin signaling pathway / 中国药房

OBJECTIVE To study the mechanism of oxymatrine inducing apoptosis of osteosarcoma MG63 cell line based on mitophagy mediated by cyclooxygenase-2 （COX-2）/PTEN-induced putative kinase-1 （PINK1）/Parkinson disease protein-2 （Parkin） signaling pathway. METHODS MG63 cells were treated with 2.0， 4.0， 8.0 mg/mL oxymatrine and 6 μmol/L 5-fluorouracil， then the apoptotic rate， the expression of apoptosis-related proteins [B-cell lymphoma-2 （Bcl-2）， Bcl-2 related X protein （Bax）]， the proportion of decrease in mitochondrial membrane potential， the level of mitophagy as well as the protein expressions of PINK1， Parkin， and microtubule-associated protein 1 light chain-3Ⅱ （LC3-Ⅱ） were detected. PINK1 small interfering RNA （siRNA） was adopted to intervene in the expression of PINK1， the cells were divided into control group， PINK1 siRNA group， oxymatrine group， and PINK1 siRNA+oxymatrine group； the protein expressions of PINK1， Parkin， and LC3-Ⅱ， the proportion of decrease in mitochondrial membrane potential （MMP） as well as apoptotic rate were detected. The lentivirus infection technique was used to overexpress COX-2， the cells were divided into control group， oxymatrine group， COX-2 group， and COX-2+oxymatrine group. The protein expressions of COX-2， PINK1， and Parkin， as well as the proportion of decrease in MMP were detected. RESULTS After being treated with oxymatrine， the apoptotic rate， the protein expressions of Bax， PINK1， Parkin， and LC3-Ⅱ， the level of mitophagy as well as the proportion of decrease in MMP were significantly increased （P＜0.05）， while the protein expression of Bcl-2 was significantly decreased （P＜0.05）. Compared with the oxymatrine group， the protein expressions of PINK1， Parkin， and LC3-Ⅱ， apoptotic rate and the proportion of decrease in MMP were significantly decreased in PINK1 siRNA+oxymatrine group （P＜0.05）. Compared with the oxymatrine group， the protein expression of COX-2 in the COX-2+oxymatrine group was increased significantly （P＜0.05）， while the protein expressions of PINK1 and Parkin as well as the proportion of 526087266@qq.com decrease in MMP were decreased significantly （P＜0.05）. CONCLUSIONS Oxymatrine can mediate the overactivity of mitophagy based on the PINK1/Parkin signaling pathway by inhibiting COX-2 expression， thus promoting the apoptosis of the MG63 osteosarcoma cell line.

Research progress on autocrine and paracrine regulation of osteosarcoma cell growth / 中国生物制品学杂志

@#Osteosarcoma(OS)is one of the most common malignant tumors in bone tissue,and its specific mechanism is not yet fully clear. Studies have shown that OS cells express different cytokines(CKs)and their receptors in the development stage of tumors,and enable them to grow autonomously and confer metastatic ability through autocrine and paracrine effects. In this regard,the most important CKs mainly includes insulin-like growth factor-1,transforming growth factor-β,chemokine 5 and interleukin-8,which can regulate the tumor microenvironment that is conducive to tumor growth,invasion and metastasis. This review summarizes the role and mode of action of CKs and their biological relevance to OS cells,hoping to provide effective new markers and therapeutic targets for clinical treatment of OS.

Synergistic effects of methotrexate and piperine on human osteosarcoma cell lines – An in-vitro study

Background: Osteosarcoma is a malignant cancer that effect bone and metastasizing to many vital organs such as lungs. There are many available drugs to treat the disease including tamoxifen, methotrexate (MTX), and cisplatin which have their own side effects and hurdles to become drugs of choice for the disease. On the other hand, introduction of herbal drugs as chemotherapeutic agents opened up new arena to potentiate the existing treatment by exhibiting synergy. Piperine (PPN) is widely used drug as anti-cancer agent as well as it has anti-inflammatory, analgesic properties, and also used in the treatment of abdominal pains, tuberculosis, arthritis, and respiratory illness. Aims and Objective: Thus, this study was designed to investigate the synergistic inhibitory potential of PPN and MTX on the MG63 osteosarcoma cell lines in vitro. Materials and Methods: The cell lines were cultured on DMEM medium and investigated for cytotoxicity of the drugs using MTT assay at 540 nm in UV. Three groups of cell lines administered with PPN, MTX, and PPN+MTX (1:1) in various concentrations and IC50 values were calculated based on the % cell viability graphs. Results: Results showed that the IC50 of PPN was 38.65, MTX was 123.98, and PPN+MTX was 15.13 proving the significant synergistic cytotoxic effect of PPN and MTX in inhibiting the proliferation of MG63 cell lines. Conclusion: Further research needs to be conducted in this field to elucidate the synergistic pathways in which PPN has shown a better anti-osteosarcoma effect when combined with MTX.

Effects of miR-143 on the migration and invasion of osteosarcoma cells by regulating MMP-13 expression / 中国骨伤

OBJECTIVE@#To explore the effect of miR-143 regulating matrix metalloproteinase(MMP)-13 expression on migration and invasion of osteosarcoma cells.@*METHODS@#The mouse osteosarcoma cell line 143B cells were cultured in 96-well plates, and blank group, negative group, positive group, and intervention group were set up. Then, the blank group did no treatment 50 μg miR-143 mimic was added to positive group, negative group added equal mimic NC (control sequence of miR-143 mimic), the intervention group was added 50 μg miR-143 mimic and 10 μg MMP-13 protein, all groups continued to culture for 3 to 6 hours, and finally the serum was aspirated to treat for half an hour. The protein expressions of miR-143 and MMP-13 in each group were measured by fluorescence quantitative PCR experiment and Western blot experiment, respectively, and the invasion and migration abilities of cells were measured by Transwell and scratch experiments.@*RESULTS@#The expression of MMP-13 protein in the positive group and the intervention group was significantly lower than that in the blank group, and the positive group was lower than the intervention group (P<0.05);The mean numbers of invasive cells in blank group, negative group, positive group and intervention group were (1 000.01±44.77), (959.25±46.32), (245.04±4.33), (634.06±33.78) cells/field, respectively;the scratch healing rate of the positive group and the intervention group was significantly lower than that of the blank group, and the positive group was lower than the intervention group (P<0.05).@*CONCLUSION@#MMP-13 is a target of miR-143, which can reduce the migration and invasion ability of osteosarcoma cells by inhibiting the expression of MMP-13.

Characterization of Cell Subsets Associated With Prognosis of Osteosarcoma Based on Single-Cell Sequencing Data / 中国医学科学院学报

Objective To explore the cell subsets and characteristics related to the prognosis of osteosarcoma by analyzing the cellular composition of tumor tissue samples from different osteosarcoma patients.Methods The single-cell sequencing data and bulk sequencing data of different osteosarcoma patients were downloaded.We extracted the information of cell samples for dimensionality reduction,annotation,and cell function analysis,so as to identify the cell subsets and clarify the cell characteristics related to the prognosis of osteosarcoma.The development trajectory of macrophages with prognostic significance was analyzed,and the prognostic model of osteosarcoma was established based on the differentially expressed genes of macrophage differentiation.Results The cellular composition presented heterogeneity in the patients with osteosarcoma.The infiltration of mononuclear phagocytes in osteosarcoma had prognostic significance(P=0.003).Four macrophage subsets were associated with prognosis,and their signature transcription factors included RUNX3(+),ETS1(+),HOXD11(+),ZNF281(+),and PRRX1(+).Prog_Macro2 and Prog_Macro4 were located at the end of the developmental trajectory,and the prognostic ability of macrophage subsets increased with the progression of osteosarcoma.The prognostic model established based on the differentially expressed genes involved in macrophage differentiation can distinguish the survival rate of osteosarcoma patients with different risks(P<0.001).Conclusion Macrophage subsets are closely related to the prognosis of osteosarcoma and can be used as the key target cells for the immunotherapy of osteosarcoma.

Synchronous Primary Parosteal Osteosarcoma and Primary Mediastinal Germ Cell Tumour with Atypical Mycobacterial Infection – A Rare Phenomenon: A Case Report

@#Mediastinal germ cell tumours are a rare group of extragonadal germ cell tumours with less than 5% prevalence of all germ cell tumours. Primary mediastinal germ cell tumours themselves account for 16-36% of the extragonadal germ cell tumours. Along the spectrum of osteosarcoma, parosteal osteosarcoma is a welldifferentiated surface osteosarcoma with a prevalence of 4% of all osteosarcoma. As such synchronous primary parosteal osteosarcoma and primary mediastinal germ cell tumour are exceedingly rare. This leads to complexity in determining the most appropriate chemotherapy for two different types of tumours and its potential side effects of reduced immunity leading to potential secondary infection. Here we report a case of a 16-year-old boy who presented with synchronous primary osteosarcoma and primary mediastinal germ cell tumour, complicated with atypical mycobacterial infection post-operatively. Additionally, we discuss our choice of chemotherapy and the management of the atypical mycobacterial infection.

Curcumin in Treatment of Osteosarcoma： A Review / 中国实验方剂学杂志

Osteosarcoma （OS） is the most common primary malignant bone tumor originating from mesenchymal stem cells， which features high degree of malignancy， strong invasiveness， easy early metastasis， and high recurrence rate. The clinical manifestations of OS are pain， local mass， limited movement， and pathological fracture. OS mainly occurs in children， adolescents， and the elderly， seriously threatening physical and mental health of patients， as well as their quality of life. The currently available therapies for OS are surgery， chemoradiotherapy， and the combination of the two. Although the therapeutic effect has been improved， tumor recurrence and metastasis and multidrug resistance still occur. Thus， the therapeutic effect is not satisfactory， especially in improving the overall survival rate of patients with metastatic OS. As a result， clinicians and researchers have been making efforts to find an effective therapy. In recent years， the mechanism of curcumin （CUR） against OS has attracted wide attention. CUR， a pigment extracted from the rhizomes or tubers of many plants， such as Curcuma longa， C. rcenyujin， and C. phaeocaulis， has a variety of pharmacological effects. Scholars have found that CUR has the effects of inhibiting proliferation， inducing apoptosis， and reversing multidrug resistance （MDR） of tumor cells， but also it has poor water solubility and low bioavailability， which limit the clinical application. This paper mainly discusses the mechanism of CUR against OS， the existing problems， new treatment methods， and future research directions， which is expected to provide new ideas for scientific researchers and provide a reference for the development and utilization of CUR in the future.

Prognostic value and mechanism of long non-coding RNA DLEU1 in osteosarcoma / 中国骨伤

OBJECTIVE@#To investigate the prognostic value and mechanism of long non-coding RNA DLEU1(LncRNA DLEU1) in osteosarcoma.@*METHODS@#The tissue samples and clinical data of 86 patients with osteosarcoma treated by orthopaedic surgery in our hospital from January 2012 to December 2014 were retrospectively collected. The expression of LncRNA DLEU1 in pathological tissues was detected by qRT-PCR, then the patients were divided into high and low expression of LncRNA DLEU1 groups. Osteosarcoma cell line HOS was divided into two groups, down-regulated expression group (si-DLEU1 group) and negative control group (si-NC group). LncRNA DLEU1 siRNA and negative control sequence were transfected by Lipofectamine 3000. Chi-square test was used to analyze the relationship between the expression of LncRNA DLEU1 and the clinicopathological factors of osteosarcoma. Kaplan-Meier method was used to compare the difference of the overall survival rate of osteosarcoma patients between the high and low expression groups of LncRNA DLEU1. The risk factors affecting the overall survival rate of osteosarcoma were analyzed by single factor and multifactor analysis. The number of invasive cells in the two groups was determined and compared by Transwell assay.@*RESULTS@#The expression of LncRNA DLEU1 in osteosarcoma tissue was higher than that in adjacent tissues (P<0.001). The expression of LncRNA DLEU1 in human osteosarcoma cell lines (MG-63, U-2 OS, and HOS) was significantly higher than that in human osteoblast line hFOB 1.19 (P<0.001). The expression of LncRNA DLEU1 was significantly correlated with Enneking stage (P<0.001), distant metastasis (P=0.016), and histological grade (P=0.028). The 1-year overall survival rate of the LncRNA DLEU1 high expression group was significantly higher than that of the low expression group (90.7% vs 60.5%, P<0.001). The 5-year overall survival rate of the LncRNA DLEU1 high expression group was significantly higher than that of the low expression group (32.6% vs 11.6%, P<0.001). Univariate analysis showed that Enneking stage (P<0.001), tumor size (P=0.043), distant metastasis (P<0.001), histological grade (P<0.001), and expression of LncRNA DLEU1 (P<0.001) were risk factors for overall survival of osteosarcoma patients. Multivariate analysis showed that high expression of LncRNA DLEU1 [HR=1.948, 95% CI(1.141, 3.641), P=0.012] and distant metastasis[HR=4.108, 95% CI(2.169, 7.780), P<0.001] were independent risk factors for overall survival of osteosarcoma patients. The number of invasive cells in si-DLEU1 group was significantly lesser than that in si-NC group(139±13 vs 357±31, P<0.001).@*CONCLUSION@#High expression of LncRNA DLEU1 is a molecular marker affecting the prognosis of osteosarcoma patients. Downregulation of LncRNA DLEU1 can inhibit the invasion of osteosarcoma cells.

Research Progress of 3D Printing Technology for Perioperative Treatment of Osteosarcoma / 肿瘤防治研究

The anatomical site of osteosarcoma is generally complex. Hence, it is difficult to accurately remove osteosarcoma and retain important nerves and blood vessels around the tumor, as well as repair and reconstruct bone defects after osteosarcoma resection. 3D printing technology can "tailor" the "bone defect" after removing the irregular osteosarcoma to achieve a good therapeutic effect of limb reconstruction. This study reviews the application of 3D printing technology in the preoperative, intraoperative, and postoperative reconstruction of osteosarcoma and bone tissue engineering scaffolds. Thus, this study systematically analyzes the advantages and suggestions of 3D printing technology based on the characteristics of 3D printing to put forward references for the accurate treatments of osteosarcoma in the future.

Correlation Between PD-1/CTLA-4 Expressions with C linicopathological Features and Prognosis of Osteosarcoma Patients / 肿瘤防治研究

Objective To explore the expression of PD-1 and CTLA-4 in osteosarcoma and their clinical significance. Methods Fifty-eight cases of osteosarcoma encountered from 2007 to 2016 were enrolled. The expression levels of PD-1 and CTLA-4 were detected through immunohistochemistry (EnVision method). Results PD-1 was positively expressed in 31 (53.4%) cases and negatively expressed in 27 (46.6%) cases. CTLA-4 was positively expressed in 19 (32.8%) cases and negatively expressed in 39 (67.2%) cases. A total of 12 (20.7%) cases were PD-1 and CTLA-4 double positive, whereas 20 (34.5%) cases were double negative, and 26 (44.8%) cases were single positive. The positive expression of PD-1 was correlated with neoadjuvant chemotherapy, tumor metastasis and relapse, and shortened survival time (P < 0.05). The positive expression of CTLA-4 was partly related with late Ennecking stage (P=0.051). Double positive expression was related to the highest tumor metastasis and relapse rates and the worst prognosis (P < 0.05), compared with double negative and single positive expression. Conclusion Positive expression of PD-1 and CTLA-4 in osteosarcoma is associated with worse prognosis, whereas double positive expression is associated with the highest tumor relapse and metastasis rates and shortest survival time. These results are potential valuable references for osteosarcoma immunotherapy.

Study progression on mechanism of long non-coding RNAs regulating drug resistance in osteosarcoma / 国际肿瘤学杂志

Osteosarcoma is the most common primary solid bone malignancy. The main factor leading to recurrence and metastasis of osteosarcoma is resistance to chemotherapy drugs. Long non-coding RNAs can affect drug resistance in osteosarcoma by regulating epithelial-mesenchymal transition, cell autophagy, apoptosis, drug efflux, and cell cycle, suggesting that long non-coding RNAs may become new targets for drug resistance in osteosarcoma treatment.

Study on the relationship between long non-coding RNA DHRS4-AS1 and disease-free survival in patients with osteosarcoma and its effect on osteosarcoma cell proliferation and migration in vitro / 肿瘤研究与临床

Objective:To investigate the relationship between long non-coding RNA (lncRNA) DHRS4-AS1 and disease-free survival in osteosarcoma patients and the mechanisms of its effect on proliferation and migration of osteosarcoma cells in vitro.Methods:The data of DHRS4-AS1 transcriptome levels and survival status of osteosarcoma patients in GEPIA database were collected since the database was established, and the patients were divided into high DHRS4-AS1 expression group and low DHRS4-AS1 expression group based on the median DHRS4-AS1 transcriptome level, with 59 cases in each group, and the Kaplan-Meier method was used to analyze the disease-free survival of the two groups. Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of DHRS4-AS1 in osteosarcoma cell lines MG-63, HOS, 143B, U-2OS, Saos2 and normal osteoblast cell line hFOB1.19, and the osteosarcoma cell line with the lowest DHRS4-AS1 expression level was selected for subsequent experiments. The plasmid carrying DHRS4-AS1 sequence and the plasmid carrying negative control sequence were transfected into the selected osteosarcoma cells as DHRS4-AS1 group and control group. CCK-8 method was used to detect the proliferation of each group of cells, and the absorbance value was used as the cell proliferation ability; cell scratch assay was used to detect the migration of each group of cells. The bioinformatics website starBase V2.0 was used to predict the target genes of DHRS4-AS1, and the dual luciferase reporter gene assay was used to verify the targeting relationship between DHRS4-AS1 and the target genes. The expression levels of target genes and downstream genes of osteosarcoma cells in control group and DHRS4-AS1 group were detected by qRT-PCR and Western blotting.Results:Survival analysis showed that the disease-free survival of osteosarcoma patients in the high DHRS4-AS1 expression group in GEPIA database was superior to that of the low DHRS4-AS1 expression group ( P < 0.001). Compared with normal osteoblastic hFOB1.19 cells, the expression level of DHRS4-AS1 was low in all osteosarcoma cells (all P < 0.01), with the lowest expression level of DHRS4-AS1 in U-2OS cells ( P < 0.001). Cell proliferation ability was reduced in U-2OS cells of the DHRS4-AS1 group after 1, 2, 3 and 4 d of culture compared with the control group (all P < 0.05). The migration rate of U-2OS cells in the DHRS4-AS1 group was lower than that in the control group [(31±6)% vs. (63±4)%, t = 4.38, P = 0.005]. starBase V2.0 website predicted that DHRS4-AS1 complementarily bound to miRNA-411-3p (miR-411-3p); dual luciferase reporter gene assay showed that miR-411-3p overexpression reduced the luciferase activity of the wild-type DHRS4-AS1 reporter gene ( P < 0.001), but had no effect on the luciferase activity of the mutant DHRS4-AS1 reporter gene ( P > 0.05). qRT-PCR showed that the relative expression of miR-411-3p in U-2OS cells of the DHRS4-AS1 group was low (0.22±0.06 vs. 1.06±0.23, t = 3.55, P = 0.012) and the relative expression of metastasis suppressor MTSS1 mRNA was high (5.58±1.03 vs. 1.06±0.22, t = 4.28, P = 0.005) compared with the control group; Western blotting showed that MTSS1 expression was elevated, and the expression levels of cell proliferation phenotype proteins CDK3 and cyclin C and cell migration phenotype proteins ZEB2 and KLF8 were low. Conclusions:Osteosarcoma patients with high expression of lncRNA DHRS4-AS1 have better disease-free survival, and its expression is low in osteosarcoma cell lines. DHRS4-AS1 may promote MTSS1 gene expression and inhibit cell proliferation and migration by targeting and down-regulating miR-411-3p expression in osteosarcoma cells.

Research progress on the role of non-coding RNA in chemotherapy resistance of osteosarcoma / 中华骨科杂志

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. With the emergence of chemotherapy resistance in recent years, the survival rate of osteosarcoma patients has reached a bottleneck. Therefore, exploration of its chemoresistance mechanism is one of the popular research directions currently. Non-coding RNA (ncRNA) is a class of RNA without the ability to encode proteins, which is classified into microRNA, long non-coding RNA, and circular RNA based on length and shape. With the development of high-throughput sequencing technology, there is increasing evidence that some non-coding RNAs are abnormally upregulated or downregulated in osteosarcoma cells and affect the response of osteosarcoma to four commonly used chemotherapeutic drugs (methotrexate, doxorubicin, cisplatin and ifosfamide) through mechanisms such as regulation of apoptosis, cell cycle, signaling pathways, intracellular drug concentration, and cellular autophagy. Therefore, thesenon-coding RNAs are expected to be novel targets for osteosarcoma treatment. In this paper, the current studies were searched and reviewed on the above three non-coding RNAs mediating chemoresistance in osteosarcoma, aiming to provide a reference for breaking the bottleneck of survival rate of osteosarcoma patients.

A new 3D-printed ankle fusion prosthesis for the treatment of osteosarcoma in the distal tibia: a case report / 中华骨科杂志

To report the short-term clinical outcome of three cases of distal tibial osteosarcoma treated with a novel 3D-printed ankle fusion prosthesis for limb preservation. The patients were admitted to the Department of Bone Tumor, Shanghai General Hospital from January 2020 to June 2021, with one male and two female cases, aged 18, 12, and 14 years, respectively, all diagnosed with distal tibial osteosarcoma (Ennecking stage IIb). A new self-designed ankle fusion prosthesis was used to perform osteosarcoma resection and prosthetic reconstruction of the distal tibia. The operation time, blood loss, postoperative American Orthopedic Foot and Ankle Society Score (AOFAS) and ankle range of motion were recorded. All the 3 patients successfully completed the operation and were followed up for 22 months, 18 months and 12 months, respectively. The operation time was 140 min, 110 min and 200 min, and the blood loss was 200 ml, 200 ml and 350 ml, respectively. At the last follow-up, the AOFAS were 86, 90 and 95 points, and the range of motion of ankle flexion and extension were 30°, 15° and 30°. There was no local recurrence or lung metastasis at the last follow-up. The novel 3D-printed ankle fusion prosthesis in the distal tibia is safe and effective for the reconstruction of bone defects after resection of osteosarcoma in the distal tibia, and the early postoperative function is satisfactory.

Research on cell membrane-coated drug delivery nanovesicles in inducing the polarization of tumor-associated macrophages and treating osteosarcoma / 中华骨科杂志

Objective:To prepare cell membrane-coated nanovesicles with targeted delivery of toll-like receptor 4 (TLR4) agonist, and to explore the effect and mechanism of inducing the polarization of tumor-associated macrophages (TAMs) and treating osteosarcoma.Methods:TLR4 agonist loaded nanovesicles were prepared by polycarbonate membrane extruders. The morphology and size of nanovesicles were detected by transmission electron microscopy (TEM) and particle size analyzer, and the drug loading performance of the nanovesicles to TLR4 agonist was investigated. TLR4 agonist loaded nanovesicles were co-incubated with macrophages in vitro, and the targeting ability of nanovesicles to macrophages and its role in regulating the function of macrophages were detected by confocal fluorescence microscopy. In vitro experiments, a cell co-culture system was established. After the upper layer macrophages were treated by the control group, the TLR4 agonist group and the TLR4 agonist loaded nanovesicle group, the lower layer osteosarcoma cells were collected for CCK-8 and cloning formation experiments to evaluate their effects on the proliferation and migration of osteosarcoma cells. In vivo experiments, an osteosarcoma subcutaneous graft tumor model was established, and mice were randomly divided into the control group, the TLR4 agonist group, and the TLR4 agonist loaded nanovesicle group. After the treatment by caudal vein, the tumor targeting ability of nanovesicles in vivo was explored through the in vivo imaging system, and the volume of tumor tissue was continuously detected. The subcutaneous tumors were stained to detect macrophage-related markers, and their effect on the polarization of macrophages was evaluated. The TUNEL fluorescence of tumor tissues was further detected.Results:TEM showed the round shape of TLR4 agonist loaded nanovesicle and the size was about 200 nm. The co-incubation of 0.05 mg TLR4 agonist with 0.1 mg nanovesicles was the best condition for the preparation of drug-loaded nanovesicles. The drug loading efficiency was about 35% and the drug loading content was about 0.11 mg/mg. The membrane-coated nanovesicles could efficiently load and deliver TLR4 agonist. TLR4 agonist loaded nanovesicles were labeled with DiD red fluorescent dye, and then the labeled nanovesicles were co-incubated with macrophages. It was found by confocal fluorescence microscopy that DiD labeled TLR4 agonist loaded nanovesicles significantly accumulated in macrophages, and the fluorescence of M1-type macrophage marker (iNOS) was significantly enhanced, which could induce M1 polarization of macrophages. In vitro experiments, it was found that the number of osteosarcoma cells in the TLR4 agonist loaded nanovesicle group was significantly reduced under the light microscope, and the cell morphology was wrinkled and rounded. CCK-8 and cloning formation experiments showed that the proliferation and migration ability of osteosarcoma cells in the TLR4 agonist loaded nanovesicle group was significantly reduced compared with the control group and the TLR4 agonist group. A subcutaneous graft tumor model was established. In vivo imaging experiments showed that TLR4 agonist loaded nanovesicles locally accumulated in tumor tissues in vivo, but were not distributed in other organs. The growth of tumor tissue was significantly inhibited in the TLR4 agonist loaded nanovesicle group. Moreover, the fluorescence of M1-type macrophage marker (iNOS) was significantly enhanced (relative fluorescence intensity: 3.27±0.19), while the fluorescence of M2-type macrophage marker (CD163) was significantly decreased (relative fluorescence intensity: 0.14±0.04). TUNEL fluorescence staining showed that the apoptosis level of osteosarcoma cells was significantly increased (relative fluorescence intensity: 9.53±0.21).Conclusion:Membrane-coated nanovesicles could targeted deliver TLR4 agonist to osteosarcoma, induce TAMspolarization, remodel tumor immunosuppressive microenvironment, promote cell apoptosis, and effectively kill osteosarcoma.

The prognosis of patients with extremity osteosarcoma who have undergone misdiagnosis and mistreatment / 中华骨科杂志

Objective:To compare outcomes between standardized and misdiagnosis and mistreatment of osteosarcoma.Methods:A retrospective analysis of patients with high-grade osteosarcoma who received appropriate surgical treatment and chemotherapy (299 cases, control group) and those who were misdiagnosed (benign or infective) and received mistreatment (23 cases, study group) between January 2009 and December 2021. Gender, age, first operation mode, recurrence time, recurrence interval, metastasis time, metastasis interval, total survival time (months), survival status in the two group and tumor site reoperation mode in the study group were statistically analyzed. Further, chi-square test was performed for comparison of the clinical between two groups. The survival analysis was performed using Kaplan-Meier test and Log-rank test.Results:All the 322 patients were followed up. In the control group, the average follow-up time was 42 months (1-137 months), the average age was 24 years (3-80 years), male 184 cases, female 115 cases, and limb salvage rate was 85.3% (255/299). Seven patients underwent amputation, and the amputation rate was 17.7% (44/299). The recurrence rate was 8.4% (25/299), the average recurrence interval was 22.8 months (7-36 months), and the metastasis rate was 28.1% (85/299), the average metastasis time was 32.7 months (0-58 months). In the study group, the average of follow-up time was 30 months (9-117 months), the average age was 36 years (5-67 years), 17 males and 6 females. Among them, eleven patients were treated with limb salvage in the second stage, and the limb salvage rate was 47.8% (11/23). Seven patients underwent amputation, and the amputation rate was 30.4% (7/23). The recurrence rate was 26.1% (6/23), the average recurrence interval was 11 months (1-42 months), and the metastasis rate was 43.4% (10/23), the average metastasis time was 20.3 months (1-44 months). The 5-year survival rate was 50.7% in the study group and 56.1% in the control group. There was no significant difference between the two groups (χ 2=0.09, P=0.760). Conclusion:The overall prognosis of patients with high-grade osteosarcoma who receive active treatment after mistreatment is similar to that of patients with standardized treatment, but the recurrence and metastasis rate is higher, the recurrence time is earlier, and the amputation rate is higher.

Physeal-sparing distal femur megaprothesis for skeletally immature patients with osteosarcoma / 中华骨科杂志

Objective:To evaluate the clinical outcome of a special physeal sparing knee prosthesis for pediatric distal femoral osteosarcoma regarding the functional outcome, retention of the growth potential of the proximal tibia, and postoperative complications.Methods:A retrospective study was conducted to review 37 pediatric patients with osteosarcoma of distal femur who were treated in a single musculuskeletal tumor center between August 2015 and January 2019. Among them, 21 were boys and 16 were girls, aged from 5 to 12 years at the time of operation, with an average age of 9.1±2.1 years and the height of 115 to 160 cm, with an average of 140±10 cm. Tumor resection of distal femur was performed and the bone defect was reconstructed by a special hinged knee prosthesis which can preserve the proximal tibial epiphyseal plate. Demographic data was recorded. Overall leg length and tibial length was assessed by full-length standing anteroposterior radiographs of bilateral lower extremity with the patella pointing anteriorly preoperativelly and postoperativelly at each follow up. And the growth potential of the affected proximal tibia was calculated by comparing with the preoperative length of tibia. Meanwhile, the functional outcome was assessed by using the Musculoskeletal Tumor Society (MSTS) system, and the postoperative complications were analysed.Results:All patients underwent the tumor resection and reconstruction operation successfully. The average operation duration was 143±41 minutes, ranging 90 to 250 minutes. The average intraoperative blood loss was 314±397 ml, ranging 30 to 2 200 ml. The patients were followed up for 24 to 64 months, averaging 42.3±12.1 months. The postoperative knee range of motion was 100-130 degrees, with an average of 115.6±7.2 degrees. The postoperative MSTS score was 23-30, with an average of 26.7±1.6. To the last follow-up, the limb length discrepancy of the lower limb was 1.3 to 10 cm, and the length of the tibia was shortened from 0 to 3.8 cm compared with the opposite side, with an average of 1.3±1.0 cm. The growth percentage of the proximal tibial epiphysis on the affected side was 30% to 100%, with an average of 70%±17%. Totally, 13 patients suffered postoperative complication, the overall incidence of complications was 35% (13/37), and prosthesis-related complications were 16% (6/37). Three patients with wound dehiscence were managed by debridement and antibiotics. Radiographs revealed femoral stem loosening in a single patient 3 years after the initial operation and then the prosthesis was converted to an adult tumor knee endoprosthesis. Two cases experienced breakage of the femoral stem at 30 and 33 months, respectively, due to an accidental injury. They received revision surgery, and a new femoral prosthesis component was replaced. One patient developed femoral stem breakage at 10 months after surgery due to fatigue fracture, which treated with revision surgery. Tumor recurrence occurred in 6 patients. Among them, tumor recurrence in soft tissue occurred in 4 patients, and treated with regional resection without further recurrence. The other 2 patients experienced tumor recurrence at the distal femoral site, and treated with resection and prosthetic revision.Conclusion:The physeal sparing pediatric knee prosthesis can preserve the growth potential of the proximal tibial epiphyseal plate with good postoperative function and low incidence of prosthesis complications. Therefore, it can be an alternativeespecially for skeletally immature patients with distal femur osteosarcoma.

Mid-term follow-up of reconstruction with liquid nitrogen-inactivated autologous bone graft in patients with diaphyseal malignant tumours / 中华骨科杂志

Objective:To explore the mid-term efficacy of liquid nitrogen-inactivated autologous tumor segment bone replantation for repairing bone defects after resection of malignant tumors in the long bone shaft.Methods:A retrospective analysis was performed on the clinical data of 16 patients treated with liquid nitrogen-inactivated autologous bone graft at Beijing Jishuitan Hospital from July 2015 to June 2017 to repair defects caused by malignant tumour resection of the diaphysis. There were 10 males and 6 females with a mean age of 23.4±11.6 years (range, 8-44 years), including 8 classic osteosarcoma, 2 high-grade surface osteosarcoma, 4 Ewing's sarcoma, 1 periosteal osteosarcoma, and 1 undifferentiated pleomorphic sarcoma. Tumors were located in the humerus in 2 cases, in the femur in 8 cases and in the tibia in 6 cases. The mean length of tumor was 12.4±4.8 cm (range, 5.5-26 cm). Postoperative imaging examination was performed every 6 months, and the healing status of the transplanted bone-host bone was evaluated based on the imaging assessment method of the International Society of Limb Salvage (ISOLS) imaging assessment after allogeneic bone transplantation, and the complications were assessed using the Henderson classification. The five-year survival rate for patients and grafted bone was calculated using the Kaplan-Meier survival curve.Results:The median follow-up was 64 (60.3, 69.8) months. At the end of follow-up, 13 patients were tumour free and 3 patients died of multiple metastases at 19, 20 and 33 months after surgery. There were 32 osteotomy ends in 16 patients, of which 30 healed, including 11 metaphyseal osteotomy ends, and the healing time was 9 (6, 12) months after replantation of the tumour segment with liquid nitrogen-inactivated autologous bone; 19 osteotomy ends in the diaphysis took 13 (9, 21) months to heal, with a statistically significant difference in healing time between different sites ( Z=-2.25, P=0.025). Sixteen patients had six complications, including two cases of non-union at the diaphyseal site, one case of failure of internal fixation due to non-union, three cases of recurrence, and no soft tissue complications or infections. One patient with failed internal fixation was treated with a vascularized tip iliac bone graft that healed 6 months after surgery. Another patient died of multiple metastases with 1 unhealed diaphysis left. Three cases of recurrence were all located in the extracranial soft tissue of the autologous tumor segment inactivated by liquid nitrogen. Among them, one case underwent reoperation and local radiotherapy, and there was still no tumor survival after 65 months of surgery, and two cases died due to multiple metastases. The five-year survival rate of patients was 81% as calculated using the Kaplan-Meier survival curve, and the graft survival rate was 100%. There was no amputation and the limb salvage rate was 100%. Conclusion:The use of liquid nitrogen-inactivated autologous tumor segment bone replantation for reconstruction of bone defects after resection of malignant tumors in the shaft has advantages of higher healing rate, shorter healing time at the metaphyseal end compared to the osteotomy end, fewer complications, and higher survival rate of the replanted bone.