m6A-modified circARHGAP12 promotes the aerobic glycolysis of doxorubicin-resistance osteosarcoma by targeting c-Myc.

Chemotherapy resistance accompanied by energy metabolism abnormality functions as one of the main reasons for treatment failure and poor prognosis. However, the function of N6-methyladenosine (m6A)-modified circular RNA (circRNA) on osteosarcoma (OS) is still unclear. Here, present research investigated the potential role and mechanism of circARHGAP12 on OS doxorubicin (Dox) resistance and aerobic glycolysis. Results indicated that circARHGAP12 was a novel m6A-modified circRNA, which was up-regulated in OS cells. Overexpression of circARHGAP12 promoted the Dox resistance half-maximal inhibitory concentration (IC50) and aerobic glycolysis (glucose uptake, lactate and ATP production) in OS cells (Saos-2/Dox, MG63/Dox). Mechanistically, m6A-modified circARHGAP12 could bind with c-Myc mRNA through m6A-dependent manner, thereby enhancing the c-Myc mRNA stability. Thus, these findings revealed the critical function of circARHGAP12 on OS Dox-resistance and aerobic glycolysis. Taken together, our study demonstrated a critical function of circARHGAP12 on OS chemotherapy resistance and energy metabolism abnormality, providing critical roles on OS treatment.

Comprehensive Profile Analysis of Differentially Expressed circRNAs in Glucose Deprivation-Induced Human Nucleus Pulposus Cell Degeneration.

Nucleus pulposus (NP) is the core substance to maintain the homeostasis of intervertebral disc and stability of biomechanics. The insufficient supply of nutrition (especially glucose) is an important factor that leads to the degeneration of NP cells. circRNAs play an important role in the process of intervertebral disc degeneration (IDD) by regulating the functions of NP cells. However, glucose deprivation-related circRNAs and their functions in IDD have not been reported. In this study, the differentially expressed circRNAs in NP cells after 0, 6, 12, and 24 h of glucose deprivation culture were detected by a microarray assay. Besides, time series clustering analysis by STEM software obtained the differentially up- and downregulated circRNAs during glucose deficiency. Then, the main functions and pathways of up- and downregulated circRNAs were predicted by the functional enrichment analysis. By constructing the circRNA-miRNA regulatory network, the potential mechanisms of the most differentially expressed circRNAs were predicted. In addition, according to in vitro validation, circ_0075062 was upregulated in degenerating NP tissues and glucose deprivation-induced NP cell degeneration. Based on Sanger sequencing and RNase tolerance assay, circ_0075062 was the circular transcript. Interfering with circ_0075062 expression could potentially alleviate the imbalance of extracellular matrix (ECM) synthesis and degradation in the NP cells induced by glucose deprivation. Together, these findings help us gain a comprehensive understanding of the underlying mechanisms of IDD, and circ_0075062 may be a promising therapeutic target of IDD.

Integrating multiple microarray dataset analysis and machine learning methods to reveal the key genes and regulatory mechanisms underlying human intervertebral disc degeneration.

Intervertebral disc degeneration (IDD), a major cause of lower back pain, has multiple contributing factors including genetics, environment, age, and loading history. Bioinformatics analysis has been extensively used to identify diagnostic biomarkers and therapeutic targets for IDD diagnosis and treatment. However, multiple microarray dataset analysis and machine learning methods have not been integrated. In this study, we downloaded the mRNA, microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA) expression profiles (GSE34095, GSE15227, GSE63492 GSE116726, GSE56081 and GSE67566) associated with IDD from the GEO database. Using differential expression analysis and recursive feature elimination, we extracted four optimal feature genes. We then used the support vector machine (SVM) to make a classification model with the four optimal feature genes. The ROC curve was used to evaluate the model's performance, and the expression profiles (GSE63492, GSE116726, GSE56081, and GSE67566) were used to construct a competitive endogenous RNA (ceRNA) regulatory network and explore the underlying mechanisms of the feature genes. We found that three miRNAs (hsa-miR-4728-5p, hsa-miR-5196-5p, and hsa-miR-185-5p) and three circRNAs (hsa_circRNA_100723, hsa_circRNA_104471, and hsa_circRNA_100750) were important regulators with more interactions than the other RNAs across the whole network. The expression level analysis of the three datasets revealed that BCAS4 and SCRG1 were key genes involved in IDD development. Ultimately, our study proposes a novel approach to determining reliable and effective targets in IDD diagnosis and treatment.

The Therapeutic Evaluation of Spinal Canal Decompression by Using the TBEIS Technique in the Treatment of Lumbar Spinal Stenosis.

OBJECTIVE: To evaluate the clinical efficacy of the percutaneous endoscopic Transforaminal Broad Easy Immediate Surgery (TBEIS) technology in elderly patients with lumbar spinal stenosis (LSS). METHODS: From February 2016 to May 2018, 35 elderly patients with LSS were treated with the TBEIS technique. There were 23 males and 12 females, aged from 53 to 72 years with a median age of 63.1 years. Preoperative, 1 day, and 1 and 12 months postoperative visual analogue scale (VAS) scores and Oswestry Disability Index (ODI) were statistically analyzed. The modified MacNab criterion was used to assess the clinical effects. The radiological outcomes were evaluated by X-ray and computed tomography (CT). RESULTS: All of the operations were successful. The operative time ranged from 120 to 170 min with a median time of 148 min. All of the patients were followed up for 12 to 38 months with a median follow-up of 18 months. Preoperative, 1 day, and 1 and 12 months postoperative VAS leg scores were 6.91 ± 0.98, 1.69 ± 0.68, 1.23 ± 0.59, and 0.91 ± 0.61, respectively, and the VAS back scores improved from 4.51 ± 0.82 to 0.66 ± 0.68. The ODI scores were 63.82 ± 7.59, 38.79 ± 6.36, 24.79 ± 3.90, and 11.33 ± 3.92, respectively. Postoperative scores of VAS and ODI were obviously improved (P < 0.01). According to the modified MacNab criteria used to evaluate the clinical effects, 11 cases achieved excellent results, 18 cases achieved good results, 4 cases achieved fair results, and 2 cases achieved poor results. There were no neurovascular injury and other complications. CONCLUSIONS: Treatment of LSS in the elderly patients by the TBEIS technology has good clinical efficacy, and the technique is safe and minimally invasive.

Cell-seeded porous silk fibroin scaffolds promotes axonal regeneration and myelination in spinal cord injury rats.

Accumulating evidence indicates that a suitable scaffold designed for the spinal cord injury (SCI) was needed to enhance the survival of transplanted Bone mesenchymal stem cells (BMSCs) and to promote nerve regeneration. The current study was aimed to evaluate the effect of the porous silk fibroin scaffold (PSFSs) seeded with BMSCS on nerve regeneration, myelination and functional recovery after SCI. We previously demonstrated that the PSFSs could bridge defected nerve with nerve fibers when applied to the transected spinal cord. And we found that BMSCs were adhered to the scaffold closely and have good biological compatibility with PSFSs. PSFSs seeded with BMSCs exhibited significant improvement in complete transverse thoracic SCI rat models. Flow cytometric assay also indicated that BMSCs grew well and adhered closely to the surface of the scaffold. The Basso-Beattie-Bresnehan (BBB) scores at each time point showed that the hindlimb motor function of each transplant group was also significantly restored. Meanwhile, growth associated protein 43 (GAP-43)marker of damaged axons regeneration and myelin basic protein (MBP) marker of maintaining the myelin structural and functional integrity, all markedly increased in PSFSs seeded with BMSCs models. Together, these results demonstrated that transplantation of PSFSs seeded with BMSCS could promote the nerve regeneration, myelination and functional recovery after SCI.