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.

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.

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.

Computed tomography aspects of thoracic metastases from osteosarcoma: pictorial essay / Aspectos tomográficos das metástases torácicas de osteossarcoma: ensaio iconográfico

Abstract Osteosarcoma is the most common primary bone tumor, with a higher incidence in the second decade of life, and it often leads to pulmonary metastases. The most common pattern seen on computed tomography is one of multiple well-defined nodules in the lung parenchyma, often with calcifications. Because of the variety of presentations of pulmonary metastases in osteosarcoma, including atypical forms, knowledge of the computed tomography aspects of these lesions is important for characterizing and evaluating the extent of the disease, as well as for distinguishing metastatic disease from other benign or malignant lung diseases. This essay discusses the main tomographic findings of pulmonary metastases from osteosarcoma.

Resumo O osteossarcoma é o tumor ósseo primário mais comum, com maior incidência na segunda década de vida, sendo as metástases pulmonares achado frequente. O padrão tomográfico mais comum das metástases pulmonares de osteossarcoma é o de múltiplos nódulos bem definidos no parênquima pulmonar, frequentemente com calcificações. Em razão da multiplicidade de apresentações das metástases pulmonares do osteossarcoma, inclusive com formas atípicas, o conhecimento dos aspectos dessas lesões na tomografia computadorizada do tórax é importante para a caracterização e avaliação da extensão da doença, além de permitir a diferenciação entre doença metastática e outras doenças pulmonares benignas ou malignas. Este ensaio discute os principais achados tomográficos das metástases pulmonares de osteossarcoma.

Efectividad de intervenciones fisioterapéuticas pre y posoperatorias en pacientes con osteosarcoma / Effectiveness of pre-and postoperative physiother-apy interventions in patients with osteosarcoma

ResumenIntroducción:La falta de información sobre la efectividad de intervenciones fisioterapéuticas en la rehabilitación de pacientes con osteosarcoma en Ecuador ha llevado a evaluaciones tardías, aumentando la agresividad de la enfermedad.Materiales y métodos:En la investigación se propuso analizar la eficacia de la intervención fisioterapéutica en las fases pre y posoperatoria, recopilando información de 35 artículos cien-tíficos mediante un enfoque documental e inductivo. La calidad metodológica se evaluó con la escala PEDro, garantizando una puntuación ≥7 para validar los estudios. Se utilizaron bases de datos como Redalyc, ProQuest, LILACS, Scopus, PubMed, SJR, Cochrane, Scielo y PEDro, aplicando estrategias de búsqueda con operadores booleanos.Resultados:En la fase pre y posoperatoria se realizan intervenciones fisioterapéuticas como masajes, estimulación nerviosa, acupuntura, crioterapia y ejercicio, mostraron beneficios sig-nificativos en la disminución del dolor, la fatiga, la ansiedad, la depresión, mejoran la movilidad y fortalecen la musculatura.Conclusión:La aplicación dentro de un enfoque multidisciplinario en pacientes con osteosar-coma dio como resultadobienestar y mejoría sintomática. Este estudio respalda la eficacia de la fisioterapia en el tratamiento integral, permitiendo la independencia de los pacientes post-tratamiento quirúrgico y protésico, destacando la importancia de implementar estas in-tervenciones desde las fases iniciales del diagnóstico

AbstractIntroduction:The lack of information on the effectiveness of physiotherapy interventions forthe rehabilitation of patients withosteosarcoma in Ecuador has led to late evaluationsof this disease, increasing its aggressiveness. Materials and methods: The research aimed to analyze the effectiveness of the physiotherapy intervention in the pre-and postoperative phases, compiling information from 35 scientific ar-ticles through a documentary and inductive approach. Methodological quality was evaluated with the PEDro scale, guaranteeing a score ≥7 to validate the studies. Databases such as Re-dalyc, ProQuest, LILACS, Scopus, PubMed, SJR, Cochrane, Scielo, and PEDro were used, ap-plying search strategies with Boolean operators.Results: In the pre-andpostoperative phases, physiotherapeutic interventions such as mas-sage, nerve stimulation, acupuncture, cryotherapy, and exercise showedsignificant benefits in reducing pain, fatigue, anxiety, and depression, improving mobility,and strengthening mus-cles.Conclusion: Amultidisciplinary approach in patients with OS improved patientwell-being and symptoms. This study supports the effectiveness of physiotherapy in comprehensive treat-ment, allowing patients to become independentafter surgical and prosthetic treatment, high-lighting the importance of implementing these interventions from the initial phases of diagno-sis.

Quiste óseo aneurismático: diferencias diagnósticas con el osteosarcoma telangiectásico. Reporte de caso / Aneurysmal bone cyst: diagnostic differences with telangiectatic osteosarcoma. A case report

Introducción: los síntomas, signos y hallazgos imagenológicos e histológicos del quiste óseo aneurismático (QOA) y el osteosarcoma telangiectásico (OT) son similares, por lo que constituyen uno de los diagnósticos diferenciales más difíciles de establecer.Presentación del caso: mujer de 19 años que asistió al servicio de urgencias de un hospital de cuarto nivel de atención en Bogotá por dolor en la cadera izquierda, donde se identificó lesión lítica en el cuello del fémur y se remitió a consulta externa. Tres días después, la paciente regresó al servicio de urgencias por dolor en la cadera izquierda e incapacidad funcional. Mediante radiografía y resonancia magnética, se identificó fractura transcervical de la cadera en el lugar de la lesión lítica, por lo que se sospechó la presencia de QOA u OT. La paciente fue llevada a cirugía y se realizó biopsia por congelación, confirmando el diagnóstico de QOA; por lo tanto, se realizó curetaje y fresado de la lesión, reducción y fijación de la fractura con sistema DHS (dynamic hip screw), y aplicación de injerto y cemento óseo. Cuatro días después del procedimiento, la paciente fue dada de alta. En el seguimiento a los ocho meses, se evidenció recuperación completa de la funcionalidad de la cadera y ausencia de dolor.Conclusión: en pacientes en los que hay una alta sospecha de este tipo de lesiones óseas, es importante realizar un estudio histopatológico para confirmar el diagnóstico de QOA u OT, e instaurar un tratamiento adecuado y oportuno, que sin duda contribuirá a un mejor pronóstico, particularmente en términos de supervivencia

Introduction: Symptoms, signs, imaging and histological findings of aneurysmal bone cyst (ABC) and telangiectatic osteosarcoma (TO) are similar, which makes them one of the most difficult differential diagnoses. Case presentation: A 19-year-old woman attended the emergency department of a quaternary care hospital in Bogotá, Colombia, due to pain in the left hip. A lytic lesion in the femur was identified and the patient was referred to the outpatient clinic. Three days later, the patient returned to the emergency department with left hip pain and functional disability. By means of X-ray and MRI, a transcervical fracture of the hip was identified at the site of the lytic lesion, so the presence of ABC or TO was suspected. The patient was taken to surgery and a frozen section biopsy was performed, confirming the diagnosis of ABC. Consequently, curettage and reaming of the lesion were undertaken, followed by reduction and fixation of the fracture using the DHS (dynamic hip screw) system, and application of bone grafting and bone cement. Four days after the procedure, the patient was discharged. A follow-up at eight months showed complete recovery of hip functionality and absence of pain.Conclusion: In patients with a high suspicion of this type of bone lesions, it is important to perform a histopathological study to confirm the diagnosis of ABC or TO, and to establish an adequate and timely treatment, which will undoubtedly contribute to a better prognosis, particularly in terms of surviva

miR-125b-5p inhibits proliferation and migration of osteosarcoma cells by negatively regulating RAB3D expression / 南方医科大学学报

OBJECTIVE@#To investigate the inhibitory effect of miR-125b-5p on proliferation and migration of osteosarcoma and the role of RAB3D in mediating this effect.@*METHODS@#The expression level of miR-125b-5p was detected by qRT-PCR in a normal bone cell line (hFOB1.19) and in two osteosarcoma OS cell lines (MG63 and HOS). A miR-125b-5p mimic or inhibitor was transfected in the osteosarcoma cell lines via liposome and the changes in cell proliferation and migration were detected with EDU and Transwell experiments. Bioinformatic analysis was conducted for predicting the target gene of miR-125b-5p, and the expression level of RAB3D in hFOB1.19, MG63, and HOS cells was detected by Western blotting. In the two osteosarcoma cell lines transfected with miR-125b-5p mimic or inhibitor, the expression levels of RAB3D mRNA and protein in osteosarcoma cells were examined with qRT-PCR and Western blotting. The effects of RAB3D overexpression, RAB3D knockdown, or overexpression of both miR-125b-5p and RAB3D on the proliferation and migration of cells were assessed using EDU and Transwell experiments.@*RESULTS@#The two osteosarcoma cell lines had significantly lower expression levels of miR-125b-5p (P < 0.05). Bioinformatic analysis predicted that RAB3D was a possible target gene regulated by miR-125b-5p. In osteosarcoma cells, overexpression of miR-125b-5p significantly lowered the expression of RAB3D protein (P < 0.05); inhibiting miR-125b-5p expression significantly decreased RAB3D expression only at the protein level (P < 0.05) without obviously affecting its mRNA level. Modulation of miR-125b-5p and RAB3D levels produced opposite effects on proliferation and migration of osteosarcoma cells, and in cells with overexpression of both miR-125b-5p and RAB3D, the effect of RAB3D on cell proliferation and migration was blocked by miR-125b-5p overexpression (P < 0.05).@*CONCLUSION@#Overexpression of miR-125b-5p inhibits the proliferation and migration of osteosarcoma cells by regulating the expression of RAB3D at the post-transcriptional level.

Value of dual-layer spectral detector CT in evaluating the intramedullary invasion of limb osteosarcoma / 中华放射学杂志

Objective:To explore the optimal keV value of the virtual monoenergetic image (VMI) for displaying the osteosarcoma by using the dual-layer spectral detector CT and to evaluate its application value in determining the extent of intramedullary invasion of osteosarcoma.Methods:From August 2021 to August 2022, 57 patients with conventional osteosarcoma of long bone confirmed by biopsy in Beijing Jishuitan Hospital, Capital Medical University were retrospectively analyzed. All patients completed dual-layer spectral CT enhanced examination before limb salvage surgery, and tumor segment resection specimens were obtained after surgery. Conventional 120 kVp image and VMI of 40, 50, 60, 70 and 80 keV were obtained by spectral CT examination, and the CT values of tumors, image noise were measured and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the corresponding images were calculated. The objective evaluation among the six groups of images were assessed with the Friedman test, and then determined the optimal keV value. The maximum distance between the intramedullary boundary of osteosarcoma and the adjacent articular surfaces was measured on the best keV VMI and the tumor segment resection specimens. The Wilcoxon signed rank test was used to find the differences and the Spearman correlation analysis was used to evaluate the correlation between the distance measured from the best keV VMI and the specimens.Results:There were significant differences in CT value, image noise, SNR and CNR between 40-80 keV VMI and 120 kVp conventional CT images ( P<0.05). The CT value, SNR and CNR of 40 and 50 keV VMI were better than 120 kVp ( P<0.001). The 50 keV VMI was chosen as the best keV VMI to measure the intramedullary extent of osteosarcoma. The distance measured from 50 keV VMI was 103.9 (80.4, 131.4) mm, while the distance measured from specimens was 113.5 (94.0, 142.0) mm, and the difference was statistically significant ( Z=-5.76, P<0.001). The 50 keV VMI measurements in 51 patients were smaller than the gross specimens, which underestimated the tumor intramedullary extent, with the difference was 11.1 (6.6, 13.8) mm. The Spearman correlation analysis demonstrated a high positive correlation of distance measured on gross specimens with the 50 keV VMI ( r s=0.960, P<0.001). Conclusions:Dual-layer spectral detector CT with 50 keV VMI is the best image to show the limb osteosarcoma. Compared with gross specimens, the distance measured from CT underestimated the intramedullary invasion range of limb osteosarcoma about 10 mm, but the two show a good correlation.

MiR-181a promotes the growth of chondrosarcoma cells by targeting PTEN / 中国医师杂志

Objective:To explore the effect of miR-181a on chondrosarcoma cell growth through phosphatase and tensin homolog(PTEN) and its possible regulatory mechanism.Methods:From January to December 2022, 10 fresh chondrosarcoma and 10 chondroma tissues from orthopedic patients of Hunan Provincial People′s Hospital were collected, and the expression of miR-181a in chondrosarcoma and chondroma tissues was detected using real-time fluorescence quantitative polymerase chain reaction (qRT-PCR); Chondrosarcoma cell SW1353 was cultured in vitro and transfected with miR-181a inhibitor (miR-181a inhibition group) and control (miR-NC, control group), respectively. The effects of miR-181a on the growth and proliferation of SW1353 cells were detected by cell counting kit (CCK-8) and clone formation test, respectively; The binding sites between miR-181a and PTEN were predicted through the Target Scan database, and verified using dual luciferase reporter gene experiments; The mimetic miR-181a (miR-181a group) and its control (miR-NC, control group) were transfected into chondrosarcoma cell SW1353, respectively. The adenosine triphosphate (ATP) content, glucose consumption, and lactic acid production in the cells were measured, and the effect of miR-181a on glycolysis of SW1353 cells was analyzed. Results:The expression of miR-181a in chondrosarcoma tissues was significantly higher than that in chondroma tissues ( P<0.05). The cell growth and clonogenesis ability of miR-181a inhibition group were significantly lower than those of control group (all P<0.05). It was predicted by Target Scan online website that there might be binding sites between miR-181a and PTEN, and co-transfection of wild-type PTEN and miR-181a could significantly reduce luciferase activity by double luciferase reporter assay ( P<0.05). The ATP content, glucose consumption and lactic acid production of miR-181a group were significantly higher than those of miR-NC group (all P<0.05). Conclusions:MiR-181a promotes the growth of chondrosarcoma cells through PTEN-mediated glycolysis.

Imaging evaluation of the efficacy and prognosis of neoadjuvant chemotherapy for osteosarcoma / 中国医师杂志

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. Neoadjuvant chemotherapy is an important part of the standard treatment mode for osteosarcoma. Preoperative evaluation of the effect of neoadjuvant chemotherapy is of great significance to the selection of surgical plan and the adjustment of subsequent treatment plan. Imaging evaluation method is one of the important ways to evaluate the efficacy of neoadjuvant chemotherapy and the prognosis of patients. It has the advantages of simple, quick and non-invasive, and has become a research hotspot.

Imaging analysis and clinical follow-up of Ewing sarcoma of bone / 中国医师进修杂志

Objective:To analyze and summarize the imaging characteristics and clinical follow-up results of Ewing sarcoma of bone.Methods:The imaging data of 23 patients with Ewing sarcoma confirmed by pathology who treatment in Drum Tower Hospital Affiliated to Nanjing University School of Medicine from May 2010 to October 2021 were retrospectively analyzed, and clinical follow-up was performed.Results:Of the 23 patients with Ewing sarcoma of the bone in this group, a total of 18 patients had follow-up results and 5 cases were lost to follow-up. Of the 18 cases, 6 cases died and 12 cases survived. The main cause of death was lung metastasis. There were 27 lesions in total, femoral diaphysis was the most common site of the disease; bone structure destruction and soft tissue mass shadows could be seen in the images of each lesion. Periosteal reaction could be seen in most of the lesions (92.59%, 25/27). There were certain differences in signs of bone destruction and periosteal reaction between different bone types.Conclusions:The imaging of Ewing sarcoma of bone mainly manifests various types of bone destruction, soft tissue masses and periosteal reactions. Ewing sarcoma of bone is mainly bone marrow metastasis and lung metastasis, and lung metastasis is the main cause of death.

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.

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.