PDGFRß modulates aerobic glycolysis in osteosarcoma HOS cells via the PI3K/AKT/mTOR/c-Myc pathway.

Osteosarcoma is a malignant tumor abundant in vascular tissue, and its rich blood supply may have a significant impact on its metabolic characteristics. PDGFRß is a membrane receptor highly expressed in osteosarcoma cells and vascular wall cells, and its effect on osteosarcoma metabolism needs to be further studied. In this study, we discussed the effect and mechanism of action of PDGFRß on glucose metabolism in human osteosarcoma (HOS) cells. GSEA, Pearson's correlation test, and PPI correlation analysis indicated positive regulation of PDGFRß on aerobic glycolysis in osteosarcoma. The results of qPCR and western blot further confirmed the prediction of bioinformatics. Glucose metabolism experiments proved that PDGF/PDGFRß could effectively promote aerobic glycolysis in osteosarcoma cells. In addition, the mitochondrial membrane potential (ΔΨm) experiment proved that the metabolic change triggered by PDGFRß was not caused by mitochondrial damage. The PI3K pathway inhibitor LY294002, MEK pathway inhibitor U0126, or Warburg effect inhibitor DCA was used to perform western blot and glucose metabolism experiments, and the results showed that PDGFBB/PDGFRß mainly activated the PI3K/AKT/mTOR/c-Myc pathway to promote aerobic glycolysis in osteosarcoma HOS cells. The newly elucidated role of PDGFRß provides a novel metabolic therapeutic target for osteosarcoma.

RNF38 inhibits osteosarcoma cell proliferation by binding to CRY1.

The PI3K/AKT pathway plays an important role in the development of osteosarcoma. RNF38 interferes with activation of the AKT pathway. Cryptochrome1 (CRY1) inhibits osteosarcoma proliferation through the AKT pathway. We aimed to clarify whether RNF38 affects the proliferation of osteosarcoma cells by regulating the PI3K/AKT pathway through its interaction with CRY1. The mRNA levels of RNF38 were determined using qRT-PCR. Protein levels of RNF38, p-p70S6, p70S6, +p-AKT, AKT, p-mTOR, mTOR, and CRY1 were detected by western blotting. The proliferation of osteosarcoma cells was detected using CCK-8 and colony formation assays. The interaction between CRY1 and RNF38 was detected by co-immunoprecipitation and GST pull-down assays. RNF38 expression was higher in Saos-2 and U20S cells than in hFOB cells. Overexpression of RNF38 promoted the proliferation of osteosarcoma cells, the number of colonies, and p-AKT and p-mTOR levels, suggesting that overexpression of RNF38 activated the PI3K/AKT pathway. In addition, RNF38 directly binds to the N-terminal of CRY1. The simultaneous knockdown of RNF38 and CRY1 restored the level of p-AKT, which was reduced by RNF38 knockdown alone. RNF38 affects the proliferation of osteosarcoma cells by regulating the PI3K/AKT pathway through its interaction with CRY1.

Long non-coding RNA DSCAM-AS1 upregulates USP47 expression through sponging miR-101-3p to accelerate osteosarcoma progression.

Osteosarcoma (OS) originating from mesenchyme is one of the most common invasive tumors of bone, and has an extremely high mortality rate. Previous studies have reported that long non-coding RNAs (lncRNAs) play essential roles in the tumorigenesis and progression of a multitude of human cancers. The lncRNA DSCAM-AS1 has been reported to be an oncogenic gene in many cancers. However, the roles and regulatory mechanisms of DSCAM-AS1 in OS have not been deeply investigated. In this study, our findings prove that DSCAM-AS1 is highly expressed in OS cells. Knockdown of DSCAM-AS1 suppressed cell proliferation, migration, and invasiveness, and induced cell apoptosis in OS. Additionally, knockdown of DSCAM-AS1 inactivated the Wnt-ß-catenin signaling pathway. Moreover, research into its molecular mechanisms confirmed that DSCAM-AS1 functions as a sponge for miR-101-3p, and that ubiquitin-specific peptidase 47 (USP47) is a target gene of miR-101-3p. Furthermore, a negative relationship between miR-101-3p and DSCAM-AS1 or USP47 was discovered. The results from our rescue assays suggest that DSCAM-AS1 regulates the progression of OS through binding with miR-101-3p to control the expression of USP47. Finally, we discovered that AKT-mTOR signaling pathway mediates the activity of DSCAM-AS1 in OS. Taken together, our results show that DSCAM-AS1 accelerates the progression of OS via the miR-101-3p-USP47 axis, which could present a new potential therapeutic treatment for OS.

miR-628-5p promotes growth and migration of osteosarcoma by targeting IFI44L.

This study investigated the role of miR-628-5p and interferon-induced protein 44-like (IFI44L) in osteosarcoma (OS) and determined whether miR-628-5p modulated OS growth by regulating IFI44L. Based on the data downloaded from Gene Expression Omnibus (GEO) database, we revealed that the expression of IFI44L was downregulated in OS and low expression of IFI44L was correlated with better prognosis of patients with OS. Biological prediction of its upstream regulatory miRNAs on the miRWalk website found that miR-628-5p is a possible upstream regulatory miRNA of IFI44L. Luciferase activity assay demonstrated that miR-628-5p could bind to the 3' untranslated region (UTR) of IFI44L, which proved the above prediction. The expression of miR-628-5p is upregulated in OS and high expression of miR-628-5p is correlated with poor prognosis of patients with OS. The results of RT-qPCR showed that the expression of miR-628-5p in MG-63, U2OS, Saos-2, and SW1353 cells was significantly higher than that in the hFOB1.19 cells. Downregulation of miR-628-5p by miR-628-5p inhibitor significantly inhibited the proliferation, migration, and invasion of MG-63 cells. By rescue assay, we found that knockdown of IFI44L rescued the proliferation and motility of miR-628-5p depleted MG-63 cells. Collectively, our present data illustrated that miR-628-5p promoted the growth and motility of OS at least partly by targeting IFI44L. Moreover, miR-628-5p and IFI44L might be proposed as promising biomarkers in OS diagnosis and treatment.

MicroRNA-211-5p promotes apoptosis and inhibits the migration of osteosarcoma cells by targeting proline-rich protein PRR11.

Osteosarcoma remains fatal in adolescents and young adults, with a 5-year survival rate of less than 20%. However, the details for mechanisms that regulate osteosarcoma metastasis are poorly understood. We analyzed the expression levels of miR-211-5p in clinical samples of osteosarcoma as well as cell lines, and found that the expression of miR-211-5p was reduced in osteosarcoma. Moreover, induction of miR-211-5p in several osteosarcoma cell lines dramatically inhibited their migration and invasiveness. Furthermore, miR-211-5p overexpression led to a significant increase in the apoptosis of osteosarcoma cell. Importantly, our in vivo xenograft experiments showed that miR-211-5p strongly inhibits tumorigenesis. Additionally, functional experiments demonstrated that miR-211-5p suppresses the expression of proline-rich protein 11 (PRR11) by directly binding to the 3' region of PRR11 mRNA. Moreover, we showed that PRR11 overexpression attenuated the increase of apoptosis and decreased migration and invasiveness when the upstream miR-211-5p was overexpressed. Our data provide new insights into the mechanisms that regulate osteosarcoma metastasis, and novel potential pharmaceutical targets for personalized medicine.

Long noncoding RNA HIF1A-AS2 facilitates cell survival and migration by sponging miR-33b-5p to modulate SIRT6 expression in osteosarcoma.

Long noncoding RNAs (lncRNAs) are emerging as vital regulators in various physiological and pathological processes. It was recently found that lncRNA HIF1A-AS2 could play oncogenic roles in several cancers. However, the function and regulatory mechanism of lncRNA HIF1A-AS2 in osteosarcoma (OS) remain largely unclear. In this study, we demonstrated that HIF1A-AS2 was overexpressed in OS tissues and cells. Downregulation of HIF1A-AS2 significantly affects multiple biological functions in OS cells, including cell proliferation, cell cycle progression, cell apoptosis, cell migration, and cell invasiveness. Mechanistic investigations demonstrated that HIF1A-AS2 can interact with miR-33b-5p and negatively regulate its expression, thereby upregulating the protein expression of miR-33b-5p's target SIRT6. Additionally, in vivo experiments using a xenograft tumor mouse model revealed that downregulation of HIF1A-AS2 suppresses tumor growth in OS. Taken together, a newly identified regulatory mechanism for the lncRNA HIF1A-AS2-miR-33b-5p-SIRT6 axis was systematically studied in OS, which could be a promising target for the treatment of OS.

Carboxypeptidase E-ΔN promotes migration, invasiveness, and epithelial-mesenchymal transition of human osteosarcoma cells via the Wnt-ß-catenin pathway.

Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents, and metastatic OS is the major cause of OS-related death. Carboxypeptidase E (CPE) is known to be highly expressed in some cancer types, and its N-terminal truncated form, CPE-ΔN, is implicated in tumor metastasis and poor prognosis. In this study, we investigated the effect of CPE-ΔN on cell migration, invasiveness, and the epithelial-mesenchymal transition (EMT) of OS cells, and illustrated the molecular mechanisms. We first constructed CPE-ΔN overexpressing human OS cell lines (143B and U2OS cells), and found that ectopic CPE-ΔN expression in OS cells enhanced cell migration and invasiveness, and promoted the EMT process. Further, overexpression of CPE-ΔN increased the levels of c-myc and nuclear ß-catenin in OS cells, which suggested the CPE-ΔN promotes activation of the Wnt-ß-catenin pathway in OS cells. Treatment with ß-catenin small interfering RNA (siRNA) inhibited the migration and invasiveness of CPE-ΔN-overexpressing cells, and reduced the expression of E-cadherin. Together, these results suggest that CPE-ΔN promotes migration, invasiveness, and the EMT of OS cells via the Wnt-ß-catenin signaling pathway.

MiR-378 promotes the cell proliferation of osteosarcoma through down-regulating the expression of Kruppel-like factor 9.

MicroRNAs (miRNAs) are small non-coding RNAs that play important roles in a variety of biological processes. Dysregulation of miRNAs is tightly associated with the malignancy of cancers. Aberrant expression of miR-378 has been observed in human cancers; however, the function of miR-378 in osteosarcoma (OS) remains largely unknown. Here, we showed that miR-378 was highly expressed in human OS tissues and cell lines. Overexpression of miR-378 significantly promoted the cell proliferation of OS cells. Molecular studies identified Kruppel-like factor-9 (KLF9) as a functional downstream target of miR-378. MiR-378 directly bound to the mRNA 3'-UTR region of KLF9 and suppressed the expression of KLF9. Highly expressed KLF9 reversed the promoting effect of miR-378 on the proliferation of OS cells. The expression level of miR-378 was negatively correlated with that of KLF9 in OS tissues. Collectively, our results demonstrated the molecular interaction between miR-378 and KLF9, indicating the therapeutic potential of miR-378 for OS.

Chimaphilin inhibits human osteosarcoma cell invasion and metastasis through suppressing the TGF-ß1-induced epithelial-to-mesenchymal transition markers via PI-3K/Akt, ERK1/2, and Smad signaling pathways.

Epithelial-to-mesenchymal transition is a cellular process associated with cancer invasion and metastasis. However, the antimetastatic effects of chimaphilin remain elusive. In this study, we attempted to investigate the potential use of chimaphilin as an inhibitor of TGF-ß1-induced epithelial-to-mesenchymal transition in U2OS cells. We found that TGF-ß1 induced epithelial-to-mesenchymal transition to promote U2OS cell invasion and metastasis. Western blotting demonstrated that chimaphilin inhibited U2OS cell invasion and migration, increased the expression of the epithelial phenotype marker E-cadherin, repressed the expression of the mesenchymal phenotype marker vimentin, as well as decreased the level of epithelial-to-mesenchymal-inducing transcription factors Snail1 and Slug during the initiation of TGF-ß1-induced epithelial-to-mesenchymal transition. In this study, we revealed that chimaphilin up-regulated the E-cadherin expression level and inhibited the production of vimentin, Snail1, and Slug in TGF-ß1-induced U2OS cells by blocking PI-3K/Akt and ERK 1/2 signaling pathway. Additionally, the TGF-ß1-mediated phosphorylated levels of Smad2/3 were inhibited by chimaphilin pretreatment. Above all, we conclude that chimaphilin represents an effective inhibitor of the metastatic potential of U2OS cells through suppression of TGF-ß1-induced epithelial-to-mesenchymal transition.

A case of polyostotic osteosarcoma with kidney metastases in a dog: histopathology and microcomputed tomographic analysis.

A 7-year- old sexually intact female Leonberg dog was evaluated for chronic lameness of the right forelimb. The bitch showed mild hyperthermia (39.3°C), a decrease in its activity, a capricious appetite, a high weight loss (4 kg in 15 days) and a right foreleg lameness. A careful clinical examination revealed a deformation of the right proximal humerus and right tibia. Radiographic examination of the right tibia, right humerus showed osteolysis of both cortical and trabecular bone with a periosteal bone proliferation in the vicinal soft tissues. The owner having refused a bone biopsy, a treatment with NSAIDs and antibiotics was prescribed. After a marked improvement during the first two weeks, an increase in lameness and activity was observed. At that time, the owner accepted the bone biopsy. Histopathologic examination evidenced an osteosarcoma but the amount of available tissue was limited. Due to the poor prognosis, he declined treatment and decided to euthanize the dog. An osteosarcoma with a large chondroid component was observed at autopsy together with ossifying kidney metastases. Histological findings revealed a grade III osteosarcoma. Conventional and undecalcified histology and X-ray microcomputed tomography findings evidenced a large and partially mineralized osteoid part with a sunburst extension in the soft tissues. This is the first time that microCT and undecalcified analyses of an osteosarcoma are presented. The osteolytic and metaplastic bone foci were easily demonstrated by this method.

Parosteal osteosarcoma of the thumb: A case report and literature review.

Parosteal osteosarcoma (PO) is a rare malignant tumor arising from the surface of the bone. Locations in the hand are even more exceptional. This low-grade osteosarcoma shows non-specific clinical and radiological presentation, making diagnosis challenging. Moreover, histologic examination is extremely difficult and can easily lead to misdiagnosis. We report the case of a 21-year-old woman who presented PO of the right thumb, initially diagnosed as a "benign exostosis" 9 years previously. En-bloc resection followed by reconstruction using a free corticocancellous iliac crest autograft provided good esthetic and functional outcome. No recurrence occurred at 2 years' follow-up. Our literature review confirmed the rarity of PO of the hand, with only 8 cases reported in the past 60 years. Amputation was the main treatment, but some authors reported limb-sparing surgery. The present result and those in the literature review support conservative surgery when feasible, with little recurrence and better functional and esthetic results. These rare tumors should not be misdiagnosed, and should be treated in specialized centers to optimize outcome.

Reconstruction of the distal radius using a double-barrel vascularized fibula flap: A case series.

Treatment of distal radius tumor sometimes requires sacrificing the epiphysis. We propose adding to currently available reconstruction options a technique using a double-barrel vascularized fibula flap fixed distally to the first carpal row, conserving midcarpal mobility. We monitored 4 cases of Campanacci III giant-cell tumor and 2 cases of osteosarcoma. After en-bloc tumor resection, a double-barrel vascularized fibula flap was lodged distally in the scaphoid and lunate and proximally in the radius. Follow-up was clinical and radiological, using DASH, PRWE and MSTS functional scores. At a median 3 years' follow-up, there were no cases of recurrence or non-union. Median ranges of motion were 23° flexion, 28° extension, 90° pronation and 62° supination. Median grip strength proportional to the contralateral side was 67%. Median DASH and PRWE functional scores were respectively 13.7 and 17 points. Median MSTS was 83%. Although this technique is challenging, with difficulties in double-barrel flap placement and in pedicle plication, the double-barrel vascularized fibula flap provided a stable and mobile wrist.

[Renal tuberculosis disease indicative of Pott's disease]. / Une atteinte tuberculeuse rénale révélatrice d'un mal de Pott.

Tuberculosisis is a serious desease, causing high morbidity and mortality. It includes frequent extra-pulmonary forms, polymorphic in their clinico-radiological presentation, resultsing in a delayed diagnosis. We report the case of a rare association of renal tuberculosis and Pott's disease. It is the case of a 19-year-old patient. He has two brothers on chronic hemodialysis. He is hospitalized for exploration of a lumbar mass and a cachectic state. Radiological imaging (MRI, scanner) suggests osteosarcoma. The renal biopsy, performed for the nephrotic syndrome, reveals the presence of a granulomatous interstitial infiltration, which suggests a tuberculosis. The anatomo-pathological study, of the excisional piece of the lumbar mass, confirms the diagnosis of tuberculous spondylodiscitis. The clinico-biological evolution, with four antituberculous therapy is favorable, except for the persistence of the glomerular syndrome.

[Prediction of chemotherapy response in primary osteosarcoma using the machine learning technique on radiomic data]. / Prédiction de la réponse à la chimiothérapie des ostéosarcomes à partir des données radiomiques issues des IRM diagnostiques.

INTRODUCTION: Osteosarcoma is the most common malignant bone tumor before 25 years of age. Response to neoadjuvant chemotherapy determines continuation of treatment and is also a powerful prognostic factor. There are currently no reliable ways to evaluate it early. The aim is to develop a method to predict the chemotherapy response using radiomics from pre-treatment MRI. METHODS: Clinical characteristics and MRI of patients treated for local or metastatic osteosarcoma were collected retrospectively in the Rhône-Alpes region, from 2007 to 2016. On initial MRI exams, each tumor was segmented by expert radiologist and 87 radiomic features were extracted automatically. Univariate analysis was performed to assess each feature's association with histological response following neoadjuvante chemotherapy. To distinguish good histological responder from poor, we built predictive models based on support vector machines. Their classification performance was assessed with the area under operating characteristic curve receiver (AUROC) from test data. RESULTS: The analysis focused on the MRIs of 69 patients, 55.1% (38/69) of whom were good histological responders. The model obtained by support vector machines from initial MRI radiomic data had an AUROC of 0.98, a sensitivity of 100% (IC 95% [100%-100%]) and specificity of 86% (IC 95% [59.7%-111%]). DISCUSSION: Radiomic based on MRI data would predict the chemotherapy response before treatment initiation, in patients treated for osteosarcoma.

[Cerebral primitive osteosarcoma, a radiological and histological atypia]. / Ostéosarcome cérébral primitif, une atypie radiologique et histologique.

INTRODUCTION: Osteosarcoma is a malignant mesenchymal tumor including cells that present an osteoblastic differentiation. On the skull, it has often extra-axial development associated with bone reaction. We report an atypical and rare case of intracranial or cerebral osteosarcoma underline the radiological and pathological diagnostic difficulties. CASE REPORT: Our case concerns a primary osteosarcoma without bone involvement in a 10-year old boy who was admitted for intracranial hypertension with progressive worsening and brachial monoparesis. Subtotal resection was performed but the postoperative course was not favorable. The child died five months after the initial surgery. Its radiological aspect prompted us evoke several diagnoses including glioma or meningioma. On the histological level, osteosarcoma, especially with poorly differentiated cells, can be deceiving with other processes, including a gliosarcoma that was revealed by simple microscopic reading before being confirmed by an immunohistochemical study. CONCLUSION: In the absence of any bone reaction or known extra-cranial location, it can be difficult to suggest the diagnosis of osteosarcoma based on imagery alone. Immunohistochemistry is essential for an accurate diagnosis.

[Osteosarcoma at a rare location: a case study]. / Osteosarcome a localisation rare. a propos d'un cas.

Bone sarcomas are uncommon tumors (3 to 5% of all bone tumors), they are even more rare after an irradiation 0.5 at 2%. Mandibular location is barely described in the literature; it mainly affects adults in their thirties. We report the case of a 43 years old man with a painful right cheek mass evolving 7 years after the end of treatment for undifferentiated nasopharyngeal carcinoma. Medical imaging has enabled us to situate the lesion, guide us towards an etiology, and to the staging and to post therapeutic monitoring. Mandibular bone osteosarcoma is a rare malignant tumor in Morocco.

Les sarcomes osseux sont des tumeurs peu fréquentes (3 à 5 % de l'ensemble des tumeurs osseuses), ils sont encore plus rares après une irradiation 0.5 à 2 %. La localisation mandibulaire est peu décrite dans la littérature, elle atteint surtout les sujets d'âge adulte (3éme décennie). Nous rapportons le cas d'un sujet de 43 ans présentant une masse jugale droite douloureuse d'évolution progressive apparue 7ans après la fin de son traitement pour carcinome indifférencié du nasopharynx. L'imagerie médicale a permis de situer la lésion, d'orienter vers une étiologie, de faire le bilan d'extension et le suivi post thérapeutique. L'ostéosarcome à localisation mandibulaire reste une tumeur maligne osseuse très rare au Maroc.

[Demographic Analysis of Patients with Osteosarcoma, Chonddrosarcoma, Ewing's Sarcoma from one Sarcoma Center in Switzerland]. / Demografische Analyse von Patienten mit Osteosarkom, Chondrosarkom und Ewing's Sarkom vom Sarkomzentrum UZH in Zürich.

Retrospective analysis of presentation, diagnosis and outcome of patients with osteosarcoma, chondrosarcoma and Ewing's sarcoma was performed for a single Sarcoma Center in Zurich at the University Hospital Balgrist. 201 patients were included. Overall survival at five and ten years were 74 ± 6%, 69 ± 7% for osteosarcoma (n = 85, since 2000), 85 ± 7%, 80 ± 9% for Ewing's sarcoma (n = 43, since 1990) and 86 ± 5%, 78 ± 9% for chondrosarcoma (n = 73, since 2000). The here presented overall survival rates from a single Sarcoma Center in Switzerland appear to be equivalent to other large international monocenter studies. The presentation and epidemiology of these patients are in accordance with large multicenter epidemiological studies. A nationwide sarcoma database (SwissSARCOS; www.sarcoma.ch) seems indispensable for more detailed analysis and quality management in such rare diseases.