Prot2GO: Predicting GO Annotations From Protein Sequences and Interactions.

Protein is the main material basis of living organisms and plays crucial role in life activities. Understanding the function of protein is of great significance for new drug discovery, disease treatment and vaccine development. In recent years, with the widespread application of deep learning in bioinformatics, researchers have proposed many deep learning models to predict protein functions. However, the existing deep learning methods usually only consider protein sequences, and thus cannot effectively integrate multi-source data to annotate protein functions. In this article, we propose the Prot2GO model, which can integrate protein sequence and PPI network data to predict protein functions. We utilize an improved biased random walk algorithm to extract the features of PPI network. For sequence data, we use a convolutional neural network to obtain the local features of the sequence and a recurrent neural network to capture the long-range associations between amino acid residues in protein sequence. Moreover, Prot2GO adopts the attention mechanism to identify protein motifs and structural domains. Experiments show that Prot2GO model achieves the state-of-the-art performance on multiple metrics.

Circ-CTNNB1 drives aerobic glycolysis and osteosarcoma progression via m6A modification through interacting with RBM15.

OBJECTIVES: Circular RNAs (circRNAs) are a subclass of noncoding RNAs, playing essential roles in tumorigenesis and aggressiveness. Recent studies have revealed the pivotal functions of circ-CTNNB1 (a circular RNA derived from CTNNB1) in cancer progression. However, little is known about the role of circ-CTNNB1 in osteosarcoma (OS), a highly malignant bone tumour in children and adolescents. METHODS: Circ-CTNNB1 was analysed by qRT-PCR, and the results were confirmed by Sanger sequencing. The interaction and effects between circ-CTNNB1 and RNA binding motif protein 15 (RBM15) were analysed through biotin-labelled RNA pull-down and mass spectrometry, in vitro binding, and RNA electrophoretic mobility shift assays. In vitro and in vivo experiments were performed to evaluate the biological functions and underlying mechanisms of circ-CTNNB1 and RBM15 in OS cells. RESULTS: Circ-CTNNB1 was highly expressed in OS tissues and predominantly detected in the nucleus of OS cells. Ectopic expression of circ-CTNNB1 promoted the growth, invasion, and metastasis of OS cells in vitro and in vivo. Mechanistically, circ-CTNNB1 interacted with RBM15 and subsequently promoted the expression of hexokinase 2 (HK2), glucose-6-phosphate isomerase (GPI) and phosphoglycerate kinase 1 (PGK1) through N6-methyladenosine (m6A) modification to facilitate the glycolysis process and activate OS progression. CONCLUSIONS: Circ-CTNNB1 drives aerobic glycolysis and OS progression by facilitating RBM15-mediated m6A modification.

Exosomal CTCF Confers Cisplatin Resistance in Osteosarcoma by Promoting Autophagy via the IGF2-AS/miR-579-3p/MSH6 Axis.

Cancer-derived exosomes participate in carcinogenesis and progression of cancers, including metastasis and drug-resistance. Of note, CTCF has been suggested to induce drug resistance in various cancers. Herein, we aim to investigate the role of cisplatin- (CDDP-) resistant osteosarcoma- (OS-) derived exosomal CTCF in OS cell resistance to CDDP and its mechanistic basis. Differentially expressed transcription factors, long noncoding RNAs (lncRNAs), miRNAs, and genes in OS were retrieved using bioinformatics approaches. Exosomes were extracted from CDDP-resistant OS cells and then cocultured with parental OS cells, followed by lentiviral transduction to manipulate the expression of CTCF, IGF2-AS, miR-579-3p, and MSH6. We assessed the in vitro and in vivo effects on malignant phenotypes, autophagy, CDDP sensitivity, and tumor formation of OS cells. It was established that CTCF and IGF2-AS were highly expressed in CDDP-resistant OS cells, and the CDDP-resistant OS cell-derived exosomal CTCF enhanced IGF2-AS transcription. CDDP-resistant OS-derived exosomes transmitted CTCF to OS cells and increased CDDP resistance in OS cells by activating an autophagy-dependent pathway. Mechanistically, CTCF activated IGF2-AS transcription and IGF2-AS competitively bound to miR-579-3p to upregulate MSH6 expression. Additionally, the promoting function of exosomal CTCF-mediated IGF2-AS/miR-579-3p/MSH6 in OS cell resistance to CDDP was confirmed in vivo. Taken together, CDDP-resistant OS-derived exosomal CTCF enhanced resistance of OS cells to CDDP via activating the autophagy-dependent pathway, providing a potential therapeutic consideration for OS treatment.

An integrative pan-cancer analysis reveals the oncogenic role of mutS homolog 6 (MSH6) in human tumors.

There are three most important mismatch repair genes in the mismatch repair system, MSH6 is one of them and it plays an essential role in DNA mismatch repair. Several emerging cell- or animal-based studies have verified that MSH6 mutations are closely linked to the occurrence, progression or metastasis of cancer, but there is still no practicable pan-cancer analysis. On account of the available datasets of the cancer genome atlas (TCGA) and Gene expression omnibus (GEO), a comprehensive analysis of the potential carcinogenic effects of the MSH6 gene was conducted in 33 human cancers. MSH6 was highly expressed in most cancers, and the high expression of MSH6 was associated with poor overall survival prognosis of patients with multiple cancers, such as adrenocortical carcinoma. MSH6 mutations occurred in most cancers and were closely related to the prognosis of cancer patients. Increased phosphorylation levels of S227 and S830 were noted in several tumors, including breast cancer and colon cancer. MSH6 expression was also observed to be correlated with cancer-associated fibroblasts and CD8+ T-cells infiltration levels in various cancer types, e. g. pancreatic adenocarcinoma or testicular germ cell tumors. Furthermore, pathway enrichment analysis demonstrated that the main biological activities of MSH6 were related to ATPase activity, mismatch repair, and DNA metabolism-related functions. Altogether, our pan-cancer research has suggested that the MSH6 expression level was closely related to the carcinogenesis and prognosis of certain tumors, which helps to know the effect of MSH6 in tumorigenesis from the point of view of clinical tumor samples.

A SEER-based nomogram accurately predicts prognosis in Ewing's sarcoma.

Ewing's sarcoma is a high-grade malignancy bone and soft tissue tumor that most commonly occurs in children and adolescents. Although the overall prognosis of Ewing's sarcoma has improved, the 5-year survival rate has not improved significantly. The study aimed to determine the risk factors independently associated with the prognosis of Ewing's sarcoma and to construct a nomogram to predict patient survival. Patients diagnosed with Ewing's sarcoma were collected from the Surveillance, Epidemiology, and End Results program database between 2004 and 2015 and further divided into training and validation cohort. Univariate and multivariate Cox regression analyses were used to identify meaningful independent prognostic factors. The nomogram was used to predict 3- and 5-year overall survival (OS) and cancer-specific survival (CSS). Finally, the nomogram was verified internally and externally through the training and validation cohorts, and the predictive capability was evaluated using the receiver operating characteristic (ROC) curve, C-index, and calibration curve and compared with that of the 7th TNM stage. A total of 1120 patients were divided into training (n = 713) and validation (n = 407) cohorts. Based on the multivariate analysis of the training cohort, a nomogram that integrated age, tumor size, primary site, N stage, and M stage was constructed (P < 0.05). The predicted C-indexes of OS and CSS of the training cohort were 0.744 (95% CI 0.717-0.771) and 0.743 (95% CI 0.715-0.770), respectively. However, the TNM stage had a C-index of 0.695 (95% CI 0.666-0.724) and 0.698 (95% CI 0.669-0.727) for predicting OS and CSS, respectively. The nomogram showed higher C-indexes than those in the TNM stage. Furthermore, the internal and external calibration curves showed good consistency between the predicted and observed values. Age, tumor size, primary site, N stage, and M stage are independent risk factors affecting the OS and CSS in Ewing's sarcoma patients. Compared with the 7th TNM staging, the nomogram consisting of these factors was more accurate for risk assessment and survival prediction in patients with Ewing's sarcoma, thus providing a novel reliable tool for risk assessment and survival prediction in Ewing's sarcoma patients.

LncRNA prostate androgen-regulated transcript 1 (PART 1) functions as an oncogene in osteosarcoma via sponging miR-20b-5p to upregulate BAMBI.

BACKGROUND: Osteosarcoma (OS) is an aggressive bone cancer that most commonly affects adolescents and children. Emerging studies have shown that long noncoding RNA (lncRNA) performs essential roles in the occurrence and development of many tumors. Prostate androgen-regulated transcript 1 (PART 1) has been reported as a tumor oncogene; despite this, the mechanisms underlying its involvement in OS are unclear. METHODS: OS and paired normal tissue samples were obtained, and gene expressions were detected by real time-quantitative polymerase chain reaction (RT-qPCR). The functions of PART 1 in OS cell proliferation, invasion, and migration were determined by Cell Counting Kit-8 (CCK-8) and Transwell assays. Furthermore, the binding sites of PART 1 and miR-20b-5p as well as those between miR-20b-5p and bone morphogenic protein and activin membrane-bound inhibitor homolog (BAMBI) were verified by bioinformatics analysis and dual-luciferase reporter assay. RESULTS: Our study found obvious overexpression of PART 1 in OS tissues and cells. Furthermore, PART 1 overexpression facilitated OS cell proliferation, invasion, and migration. Further mechanistic investigations revealed that PART 1 could sponge to miR-20b-5p, which was expressed at a low level in OS tissues and cells. Importantly, miR-20b-5p overexpression inhibited OS cell proliferation, invasion, and migration. Additionally, BAMBI was confirmed as a downstream gene of miR-20b-5p, and its expression was reversely modulated by miR-20b-5p and positively modulated by PART 1. Rescue experiments suggested that BAMBI was involved in PART 1-mediated promotion of OS progression. CONCLUSIONS: PART 1 serves as a competing endogenous RNA to promote OS tumorigenesis via its regulation of the miR-20b-5p/BAMBI axis, which may provide a promising therapeutic biomarkers for OS patients.

LncRNA TUG1 promotes Ewing's sarcoma cell proliferation, migration, and invasion via the miR-199a-3p-MSI2 signaling pathway.

The aim of this study was to investigate the roles and potential mechanisms of long non-coding RNA (lncRNA) taurine upregulated gene 1 (TUG1) in the proliferation, migration, and invasion of Ewing's sarcoma cells. RT-qPCR was used to detect the expression of TUG1, microRNA-199a-3p (miR-199a-3p), and musashi2 (MSI2) in Ewing's sarcoma tissues and cell lines. Kaplan-Meier overall survival curves showed the survival rates of Ewing's sarcoma patients with high and low expression of TUG1. The association between the expressions of TUG1/MSI2 and miR-199a-3p in Ewing's sarcoma tissues was assessed by Pearson's correlation analysis. Cell proliferation, migration, and invasion were detected by CCK-8 assay and Transwell assay, respectively. The protein level of MSI2 was determined using western blotting. The interaction between TUG1/MSI2 and miR-199a-3p was validated by the dual-luciferase reporter assay. The levels of TUG1 and MSI2 were increased, while the level of miR-199a-3p was decreased in Ewing's sarcoma tissues and cells. High expression of TUG1 or MSI2 indicated a decreased overall survival rate of Ewing's sarcoma patients. TUG1/MSI2 level was negatively correlated with miR-199a-3p level. While TUG1 level was positively correlated with MSI2 level. In Ewing's sarcoma cells, knockdown of TUG1/MSI2 or overexpression of miR-199a-3p inhibited cell proliferation, migration, and invasion, whereas the overexpression of TUG1/MSI2 presented the opposite results. TUG1 functioned as a competing endogenous RNA to regulate MSI2 expression by sponging miR-199a-3p. Finally, miR-199a-3p inhibitor or MSI2 overexpression counteracted the TUG1 knockdown-mediated inhibitory effect on Ewing's sarcoma cell proliferation, migration, and invasion. TUG1 promotes proliferation, migration, and invasion of Ewing's sarcoma cells via sequestering miR-199a-3p to enhance the MSI2 expression, suggesting that TUG1 might be a potential target for treating Ewing's sarcoma.

Erratum: Beclin-1 knockdown decreases proliferation, invasion and migration of Ewing sarcoma SK-ES-1 cells via inhibition of MMP-9.

[This corrects the article DOI: 10.3892/ol.2017.7667.].

Ubiquitin-like protein FAT10 promotes osteosarcoma glycolysis and growth by upregulating PFKFB3 via stabilization of EGFR.

Osteosarcoma is a major cause of cancer-related deaths in adolescents. While it thrives in a state of malnutrition, the mechanism of metabolic stress adaptation via metabolic reprogramming is unclear. Here, we found that the level of FAT10, a ubiquitin-like protein, was significantly higher in tumors than in adjacent normal tissues. Moreover, high FAT10 levels were closely related to increased malignancy and shorter survival time in osteosarcoma patients. Multivariate analysis also showed that FAT10 overexpression was an independent predictor of poor prognosis. Functional assays indicated that FAT10 promoted osteosarcoma cell proliferation by inducing glycolysis. In addition, FAT10 knockdown reduced the level of PFKFB3, a positive regulator of glycolysis in many cancers. A positive correlation was found between FAT10 and PFKFB3 levels in osteosarcoma tissues, further indicating that FAT10 induced an increase in glycolysis and that cell growth depended on PFKFB3. Interestingly, FAT10 regulated PFKFB3 expression by directly binding to EGFR and inhibiting its ubiquitination and degradation. These results shed light on the mechanisms responsible for osteosarcoma cell survival in the malnourished tumor microenvironment. Further, the results provide insights into the role of FAT10 in the adaptation of osteosarcoma cells to metabolic stress.

Long non-coding RNA H19 promotes the proliferation and invasion of lung cancer cells and regulates the expression of E-cadherin, N-cadherin, and vimentin.

BACKGROUND: This study aimed to explore the effect of long non-coding RNA (LncRNA) H19 on the proliferation and invasion of lung carcinoma cells A549, and to determine its molecular targets. METHODS: A549 cells were with either LncRNA H19 or LncRNA H19 shRNA, and the expression levels of LncRNA H19 were evaluated by quantitative real-time PCR (RT-PCR). We measured cell proliferation using the CCK-8 assay, cell counting assays, and colony formation assay in response to shLncRNA H19-2. Cell migration and invasion were assessed by wound healing assay and Transwell assay, respectively. The mRNA and protein expression levels of E-cadherin, N-cadherin, and vimentin were determined by RT-PCR and western blot, respectively. RESULTS: The three LncRNA H19 shRNAs used in our study significantly reduced the expression levels of LncRNA H19 in A549 cells (P<0.05). Moreover, LncRNA H19 shRNA 2 (shLncRNA-2) was the most potent inhibitor of LncRNA H19 expression, and was selected for further experimentation. Transfection with shLncRNA H19-2 significantly decreased the proliferation, migration, and invasion of A549 cells, while overexpression of LncRNA H19 had the opposite effect in these cells (P<0.05). In response to shLncRNA H19-2, the expression levels of E-cadherin were notably elevated (P<0.05), while the expression levels of N-cadherin and vimentin were decreased (P<0.05). In contrast, overexpression of LncRNA H19 induced the expression of E-cadherin, and blocked the expression of N-cadherin, and vimentin (P<0.05). CONCLUSION: Our results suggest that LncRNA H19 mediates the proliferation and invasion of lung cancer cells via upregulation of N-cadherin and vimentin, and downregulation of E-cadherin.

Efficacy of celastrol combined with cisplatin in enhancing the apoptosis of U-2OS osteosarcoma cells via the mitochondrial and endoplasmic reticulum pathways of apoptosis.

Osteosarcoma is a common primary malignant tumor of bone, and the poor prognosis and low 5-year survival rate have not improved for three decades. The present study aimed to study the effect a combination of celastrol and cisplatin on the human osteosarcoma cell line U-2OS, and to investigate the mechanism by which celastrol/cisplatin induces the apoptosis of osteosarcoma cells. MTT and Annexin V-FITC/PI assays were used to evaluate the effects of combined celastrol/cisplatin on growth and apoptosis, respectively, in U-2OS cells. Morphological changes accompanying cell growth inhibition were observed using a fluorescence microscope. Combination index (CI) analysis was used to evaluate the combinatorial effects of celastrol/cisplatin treatment. Western blotting was used to quantify the expression of apoptosis-associated proteins. It was identified that celastrol/cisplatin inhibited the growth of U-2OS cells in a dose-dependent manner. CI analysis revealed that combined celastrol/cisplatin demonstrated a synergistic effect in U-2OS cells, with CIs ranging from 0.80 to 0.97 at effect levels from IC10 to IC70. In addition, it was observed that celastrol/cisplatin upregulated the expression of Bcl-associated X protein, cytochrome c, caspase-3 and C/EBP homologous protein, and downregulated the expression of Bcl-2, poly(ADP-ribose) polymerase, 78 kDa glucose-regulated protein and caspase-9, whereas the expression of caspase-8 remained unchanged. To conclude, celastrol/cisplatin induced apoptosis in U-2OS cells via the mitochondrial and endoplasmic reticulum pathways, particularly in the former. Celastrol/cisplatin therefore exhibits potential as a novel therapeutic combination for the treatment of osteosarcoma.

A rare case of giant osteoblastoma of the sacrum.

BACKGROUND: An osteoblastoma is a rare benign bone tumor characterized by formation of osteoid tissue and primitive bone and occurs more often in men than in women. They are often secondary to an osteoid osteoma and can be located at any site on the skeleton. Lesions generally involve the posterior elements of the spine, such as the pedicle and the lamina. CASE PRESENTATION: This study reports the case of a 25-year-old female who suffered from an osteoblastoma of the right sacrum with repeated swelling and pain in the right lumbosacral region for approximately 6 months. Computed tomography (CT) and magnetic resonance imaging (MRI) of the pelvis revealed a segmented, expansive, multiseptate lesion. Resection with wide margins was performed and a huge cavity of approximately 15â€¯× 8â€¯× 4.4 cm in the right sacrum and pelvis was formed after complete curettage of the tumor. The pathological analysis of the resected tissue was consistent with a benign osteoblastoma. A follow-up was performed 2 years later and the patient was eventually relieved of the pain, the mobility of the right leg was improved and the CT scan demonstrated no evidence of recurrence. CONCLUSION: Osteoblastomas most commonly occur in the spine but rarely also in the sacrum. Large core needle biopsies play an important role in the diagnostics. Intralesional surgery can be performed for treatment of osteoblastomas.

Inhibitory effect of MSH6 gene silencing in combination with cisplatin on cell proliferation of human osteosarcoma cell line MG63.

Osteosarcoma (OS) is one of the most common primary bone malignancies, with the survival rate of patients with OS remaining low. Therefore, we conducted this study to identify the potential role combination of both MSH6 gene silencing and cisplatin (DDP) plays in OS cell proliferation and apoptosis. Microarray-based gene expression profiling was used to identify the differentially expressed genes (DEGs) in patients with OS, as well as microRNAs (miRNAs) that regulate the candidate gene. OS tissues from 67 patients with OS along with normal tissues from 24 amputee patients were collected for detection of the positive expression of mutS homolog 6 (MSH6) protein, mRNA, and protein expressions of c-myc, cyclin D1, l-2, B-cell lymphoma 2 (Bcl-2), Stathmin, proliferating cell nuclear antigen (PCNA), and Bcl-2-associated X (Bax). Moreover, after MSH6 silencing and DDP were treated on the selected human OS cell line MG63 with the highest expression of MSH6, cell viability, cell cycle distribution, and apoptosis were detected. The microarray analysis showed that MSH6 was upregulated in OS chip data. Furthermore, silencing MSH6 combined with DDP reduced expressions of c-myc, cyclin D1, Bcl-2, Stathmin, and PCNA, and elevated Bax expression, whereas inhibiting OS cell viability, impeding cell cycle distribution, and inducing apoptosis. In conclusion, our preliminary results indicated that the combination of MSH6 gene silencing coupled with DDP may have a better effect on the inhibition of OS cell proliferation and promote apoptosis, potentially providing targets for the OS treatment.

Giant sacrococcygeal chordoma: A case report.

RATIONALE: Chordoma is a relatively rare tumor that accounts for 1% to 4% of all malignant bone tumors, with an annual incidence of <0.1 per 100,000 people. Although chordoma is aligned with the axis of the spine and most commonly develops in the sacrum, to the best of our knowledge, giant sacrococcygeal chordoma is extremely rare. PATIENT CONCERNS: A 61-year-old Chinese man presented with a massive dorsal sacral mass. The patient's primary complaint was that, during the last two months, the mass had been increasing in size and his right lower extremity was uncomfortable while he was sitting, although the discomfort was relieved when he was standing. DIAGNOSES: Based on the imaging findings, we suspected that the sacrococcygeal mass was a chordoma, and a postoperative pathological examination confirmed the diagnosis of a sacral chordoma. INTERVENTION: The patient underwent extensive open surgery to achieve complete resection of the sacrococcygeal mass. An occlusion balloon catheter was used in the abdominal aorta to minimize intraoperative bleeding and maintain a clear surgical field. OUTCOMES: The patient was discharged without complications at 27 days after surgery. The 3-month follow-up revealed that the patient had recovered well, the discomfort in his right lower extremity while standing had completely resolved and that there was no evidence of recurrence. LESSONS: The development of chordoma is not associated with clear symptoms, although early diagnosis and treatment are needed to prevent invasion of the nearby tissues and organs. Therefore, we believe that surgical treatment of sacral chordoma is effective, although care must be taken to completely remove all residual tumor tissue and reduce the risk of recurrence. Besides, This report adds to our limited understanding of the rare giant sacrococcygeal chordoma.

Lumbar spinal canal osteosarcoma: A case report.

RATIONALE: Osteosarcoma is a rare neoplasm in the lumbar spine. Although osteosarcoma can arise in any portion of the skeleton, it very rarely arises in the spinal canal, which accounts for <0.1% of all cases of adult sarcomas. Here, we describe a case of osteosarcoma arising in the L4-5 spinal canal. PATIENT CONCERNS: The present report describes the case of a 55-year-old female patient with osteosarcoma of the L4-5 spinal canal. DIAGNOSES: The patient was initially diagnosed with lumbar spinal stenosis and underwent lumbar fusion at a local hospital. At the 4-month follow-up, the patient reported a marked increase in numbness and pain in the lumbar region and lower limbs. Based on magnetic resonance imaging, we diagnosed a postoperative infectious lesion of the lumbar spine. INTERVENTIONS: The patient underwent surgery for complete removal of the mass lesion. The mass measured 3 × 2.5 × 0.7 cm in size and was located in the L4-5 spinal canal. OUTCOMES: Based on histological and immunohistochemical findings, the diagnosis of osteosarcoma was confirmed by an expert pathology consultant. The patient then received chemotherapy. Postoperative follow-up at 6 months revealed no evidence of recurrent disease or residual side effects from therapy. LESSONS: Osteosarcoma in the L4-5 spinal canal is extremely rare and very difficult to distinguish histologically from benign nervous and fibrous tissue. This is a very valuable case, which highlights the need for orthopedic surgeons to consider this when diagnosing patients with spinal tumors.

Beclin-1 knockdown decreases proliferation, invasion and migration of Ewing sarcoma SK-ES-1 cells via inhibition of MMP-9.

Although Beclin-1, a well-known key regulator of autophagy, has been demonstrated to serve a function in a number of disorders, including cancer, aging and degenerative diseases, its biological function in Ewing sarcoma (ES) remains unresolved. The objective of the present study was to determine the in vitro effect of Beclin-1 knockdown on the growth and malignant phenotype of ES SK-ES-1 cells, which have increased endogenous expression of Beclin-1 compared with RD-ES cells, and to investigate the underlying molecular mechanism. Cell proliferation, invasion and migration were investigated using CCK-8, Boyden chamber Transwell, and wound healing assays, respectively. Western blot analysis was used to detect expression levels of matrix metalloproteinase (MMP)-2 and MMP-9, which are associated with the malignant phenotype. Beclin-1 knockdown significantly inhibited proliferation, invasion and migration of SK-ES-1 cells. Western blot analysis revealed that Beclin-1 knockdown caused a significant reduction in the expression of MMP-9; no marked changes in MMP-2 expression were observed in the si-Beclin-1 group compared with the control group. The results of the present study suggest that Beclin-1 serves a function in proliferation, tumor progression and inhibition of autophagy in ES, and demonstrates it's potential as a target to increase the efficacy of anticancer agents.

Therapeutic effect of neoadjuvant chemotherapy combined with curettage to treat distal femoral osteosarcoma: A case report.

RATIONALE: Osteosarcoma is the most common malignant bone tumor in children and adolescents. Metastasis occurs early, the mortality rate is high, and the tumor results in a tremendous physical, mental, and economic burden on patients. Therefore, the treatment of osteosarcoma has been important for orthopedic surgeons. However, treatment has always been a difficult problem globally. PATIENT CONCERN: We present the case of a 22-year-old girl with increasing local pain in the distal left thigh. DIAGNOSES: The patient was initially diagnosed as bone cancer according to computed tomography (CT) and X-ray imaging. And the patient was further diagnosed as osteosarcoma via to puncture biopsy of the left distal femur. INTERVENTIONS: Local arterial infusion chemotherapy, systemic intravenous chemotherapy, and curettage was conducted because of limb salvage program. OUTCOMES: The patient was doing well with no evidence of local or distant recurrence 7 years after the surgery. LESSONS: Our case indicated that limb osteosarcoma patients can undergo a limb salvage program of local arterial infusion chemotherapy, systemic intravenous chemotherapy, and curettage.

Comparing the efficacy of short-segment pedicle screw instrumentation with and without intermediate screws for treating unstable thoracolumbar fractures.

It is generally acknowledged that short-segment pedicle screw instrumentation is the preferred surgical method for thoracolumbar fractures. However, the use of short-segment instrumentation with or without intermediate screws at the fracture level remains controversial.We retrospectively evaluated 44 patients (28 men, 16 women) with unstable thoracolumbar fractures. The patients were divided into 2 groups according to the surgical method used. In group 1, 24 patients underwent surgery with a posterior approach via short-segment pedicle screw instrumentation (1 level above and 1 level below the fractured level). In group 2, 20 patients received an additional 2 screws at the fractured vertebrae. Clinical and radiologic parameters were evaluated before surgery and at 1 week, 6 months, and 1 year after surgery.We found no significant difference in the demographic characteristics between the 2 groups. No significant difference was observed in the operative time and intraoperative blood loss between the 2 groups. Clinical outcomes also showed no significant differences between the groups preoperatively or at all follow-up periods. The correction of the Cobb angle (CA) 1 week after surgery was better in group 2, whereas the anterior vertebral body height of the fractured level (AVHF) and compression ratio of the AVHF (AVHFCR) were not significantly different between the 2 groups 1 week after surgery. Moreover, group 2 had better maintenance of restored CA, AVHF, and AVHFCR at the fractured level than did group 1 at 6 months and 1 year postoperatively. In addition, the reduction of mid-sagittal diameter (MSD) of spinal canal 1 week and 1 year after surgery was better in group 2. Besides, bone fragments in the spinal canal have a tendency to be less in group 2 1 week and 1 year after surgery.Reinforcement with intermediate screws for a single thoracolumbar fracture not only enhanced the stability of the internal fixation system, but it was also conducive to the correction of kyphosis and the maintenance of the reduction effects. Furthermore, this method is helpful to restore the spinal canal and reduce the bone fragments in the spinal canal. However, more long-term follow-up studies are needed.

ABT-737 potentiates cisplatin-induced apoptosis in human osteosarcoma cells via the mitochondrial apoptotic pathway.

ABT-737 is a BH-3 mimetic that inhibits Bcl-2 and induces apoptosis of cancer cells, which has potential for anticancer therapies. Studies have shown that Bcl-2 expression in human osteosarcoma (OS) cells plays a significant role in tumor progression; however, its effects on OS cell apoptosis are still unknown. Therefore, we examined whether ABT-737 was effective in eliminating human U-2OS cells, either alone or in combination with the chemotherapy drug cisplatin [cis-diamminedichloroplatinum (II); DDP]. Furthermore, we studied the molecular mechanisms of ABT-737 in combination with DDP to induce apoptosis. To analyze the role of ABT-737 and/or DDP on osteosarcoma progression, CCK-8 viability assay, flow cytometry, Hoechst 33258 staining, and western blots were performed. Combined use of ABT-737 and DDP synergistically suppressed cell viability and induced apoptosis in human U-2OS cells when compared with either compound treated alone at low doses. We found that the combination of ABT-737 and DDP upregulated the expression of the pro-apoptotic protein Bax and downregulated the expression of the pro-survival protein Bcl-2, resulting in a change in the Bax/Bcl-2 ratio, release of cytochrome c, and activation of the mitochondrial apoptotic pathway, which resulted in caspase-9 and caspase-3 activation and PARP cleavage. Our results demonstrated that ABT-737 alone has a nominal influence on human U-2OS cells when treated within the clinically administered range, but when combined with DDP, it can inhibit the proliferation of human U-2OS cells by inducing apoptosis via the mitochondrial apoptotic pathway.

Celastrol negatively regulates cell invasion and migration ability of human osteosarcoma via downregulation of the PI3K/Akt/NF-κB signaling pathway in vitro.

Osteosarcoma (OS) is a primary malignant tumor of the bone, with a tendency to metastasize early. Despite the advances in treatment options, more than 30% of patients develop distant metastases, and the prognosis of these patients with metastases is extremely poor. Celastrol has been demonstrated to manifest multiple pharmacological activities, including induction of apoptosis in numerous types of cancer cell lines. Our previous studies have also suggested that Celastrol is capable of inducing apoptosis of human osteosarcoma cells via the mitochondrial-dependent pathway. The purpose of this study was to investigate the effects of Celastrol on the migration and invasion of human osteosarcoma U-2OS cells in vitro. Cell migration and invasion were investigated using wound healing and Boyden chamber Transwell assays. We observed that Celastrol suppressed cell invasion and migration in human osteosarcoma U-2OS cells. Furthermore, protein expression levels of phosphorylated phosphatidylinositol 3-kinase (PI3K), Akt, inhibitor of κB kinase α/ß, inhibitor of κB α, nuclear factor-κB (NF-κB subunit p65) and matrix metalloproteinase (MMP)-2 and -9 were measured by western blot analysis. We observed that the PI3K/Akt/NF-κB signaling pathway was inhibited following Celastrol treatment. In addition, the expression levels of MMP-2 and -9 proteins were also reduced significantly following Celastrol treatment. Therefore, we confirmed that Celastrol suppressed osteosarcoma U-2OS cell metastasis via downregulation of the PI3K/Akt/NF-κB signaling pathway in vitro.