A novel ferroptosis-related microRNA signature with prognostic value in osteosarcoma.

The induction of ferroptosis is suggested to be a potential therapeutic strategy for cancers. MicroRNAs (miRNAs) are reported to play an important role in cell death processes. This study aims to construct and validate a risk model based on ferroptosis-related miRNAs (FR_miRNAs) to predict prognosis and identify novel therapeutic targets for osteosarcoma. Data from the Therapeutically Applicable Research to Generate Effective Treatments database are used as the training cohort. A prognostic signature based on two FR_miRNAs (miR-635 and miR-593) is developed using univariate Cox regression, least absolute shrinkage and selection operator regression, and multivariate Cox regression analyses. The area under the curve values of the prognostic signature to predict the 1-year, 2-year, 3-year, and 5-year overall survival rates in patients with osteosarcoma are 0.782, 0.781, 0.722, and 0.777, respectively, indicating a good predictive ability. Based on the risk score, patients are divided into low-risk and high-risk groups. Patients with high-risk scores are associated with poor survival. The risk level is determined to be an independent prognostic factor. A nomogram is established for predicting prognosis. The expression levels of PRNP (miR-635-related ferroptosis-related gene (FRG); P=0.024) and HILPDA (miR-593-related FRG; P=0.025) are significantly different between the low-risk and high-risk groups. All results are validated in an external cohort (GSE39040). The results of the functional assay reveal that miR-635 mimics inhibit osteosarcoma (OS) cell proliferation and migration, whereas miR-593 overexpression exerts the opposite effect. In conclusion, miR-635 and miR-593 exert contrasting regulatory effects on OS cell proliferation and migration.

Identification and Characterization of a Novel Endo-ß-1,4-Xylanase from Streptomyces sp. T7 and Its Application in Xylo-Oligosaccharide Production.

A xylanase-producing strain, identified as Streptomyces sp. T7, was isolated from soil by our lab. The endo-ß-1,4-xylanase (xynST7) gene was found in the genome sequence of strain T7, which was cloned and expressed in Escherichia coli. XynST7 belonged to the glycoside hydrolase family 10, with a molecular mass of approximately 47 kDa. The optimum pH and temperature of XynST7 were pH 6.0 and 60 °C, respectively, and it showed wide pH and temperature adaptability and stability, retaining more than half of its enzyme activity between pH 5.0 and 11.0 below 80 °C. XynST7 showed only endo-ß-1,4-xylanase activity without cellulase- or ß-xylosidase activity, and it showed maximal hydrolysis for corncob xylan in all the test substrates. Then, XynST7 was used for the production of xylo-oligosaccharides (XOSs) by hydrolyzing xylan extracted from raw corncobs. The maximum yield of the XOS was 8.61 ± 0.13 mg/mL using 15 U/mL of XynST7 and 1.5% corncob xylan after 10 h of incubation at 60 °C. The resulting hydrolysate products mainly consisted of xylobiose and xylotriose. These data indicated that XynST7 might by a promising tool for various industrial applications.

Combination of ultrathin micro-patterned MXene and PEDOT: Poly(styrenesulfonate) enables organic electrochemical transistor for amperometric determination of survivin protein in children osteosarcoma.

An ultrathin micro-patterned MXene/PEDOT:PSS-based organic electrochemical transistor biosensor was constructed, which can significantly amplify the amperometric signal and transistor's performance. A novel interdigitated OECTs biosensor has been developed for reliable determination of survivin for the following considerations: (1) The synergistic effect of intercalated MXene and ionic PEDOT:PSS enhanced the mobility and volumetric capacitance of OECTs biosensor. (2) Compared with the best previous literatures, our assay demonstrated enhanced detection limit of survivin down to 10 pg mL-1, as well as satisfactory selectivity, reproducibility, and reliability. (3) Comparison of OECTs against commercial ELISA kit yielded favorable linearity (Y = 1.0015*X + 0.0039) and correlation coefficient (R2 = 0.9717). Those advantages are expected to pave the way to design of an OECTs biosensor with robustness, non-invasiveness, and miniaturization for the point-of-care applications.

LncRNA TTN-AS1 regulates osteosarcoma cell apoptosis and drug resistance via the miR-134-5p/MBTD1 axis.

AIM: To explore the mechanism by which long non-coding RNA (lncRNA) TTN-AS1 regulates osteosarcoma cell apoptosis and drug resistance via the microRNA miR-134-5p/malignant brain tumour domain containing 1 (MBTD1) axis. RESULTS: The lncRNA TTN-AS1 was highly expressed in osteosarcoma and was associated with poor prognosis. The lncRNA TTN-AS1 promoted cell viability and inhibited apoptosis. MiR-134-5p targeted MBTD1, which was regulated by lncRNA TTN-AS1. MBTD1 was highly expressed in osteosarcoma and was associated with poor prognosis. MBTD1 promoted cell viability and inhibited apoptosis, and knockdown of MBTD1 reversed the cancer-promoting effects of lncRNA TTN-AS1. Downregulation of lncRNA TTN-AS1 reduced drug resistance. CONCLUSION: In osteosarcoma, lncRNA TTN-AS1 promoted the expression of MBTD1 by targeting miR-134-5p and regulated cell growth, apoptosis and drug resistance. METHODS: The expression characteristics of genes in osteosarcoma patients were analysed using bioinformatics. Plasmid transfection technology was applied to silence or overexpress lncRNA TTN-AS1, miR-134-5p and MBTD1. Western blotting and quantitative polymerase chain reaction (qPCR) were used to detect protein and RNA, respectively. A cell counting kit 8 (CCK-8) and flow cytometry were used to detect cell viability and apoptosis. The effects of lncRNA TTN-AS1 and MBTD1 on osteosarcoma in vivo were studied by using a tumour burden assay.

Which Combination Treatment Is Better for Spinal Metastasis: Percutaneous Vertebroplasty With Radiofrequency Ablation, 125I Seed, Zoledronic Acid, or Radiotherapy?

BACKGROUND: Percutaneous vertebroplasty (PVP) can not only alleviate pain but also restore mechanical stability with injection of bone cement, whereas it exhibits a poor effect on antitumor activity. But through combinations with other therapies, it may be possible to achieve the maximum effect in clinical treatment. Thus, this study is designed to assess the clinical efficacy of PVP separately combined with 4 ways for spinal metastasis (SM) treatment. STUDY QUESTION: Which combination treatment is better for spinal metastasis, percutaneous vertebroplasty with radiofrequency ablation, I seed, zoledronic acid or radiotherapy? STUDY DESIGN: A total of 169 patients with SM were retrospectively recruited and randomly assigned to 4 groups to receive 4 different ways separately: 49 patients (group A) received PVP plus I seed, 51 (group B) received PVP plus radiofrequency ablation (RFA), 38 (group C) underwent PVP plus zoledronic acid (ZA), and 31 (group D) underwent PVP plus radiotherapy (RT). MEASURES AND OUTCOMES: All of them underwent routine examinations before operation. Visual analog scale (VAS), World Health Organization (WHO) Pain Relief, and ODI were applied to evaluate pain relief and motor function. RESULTS: PVP plus RT achieved the best efficacy in relieving pains, with the highest WHO Pain Relief (P < 0.05). The PVP plus RFA exhibited lowest ODI, suggesting the best outcome after treatment (P < 0.05). The PVP plus I showed the lowest VAS score, but it was the worst to improve the routine exercise ability and relieve pains from patients. The PVP plus ZA presented higher VAS and ODI (P < 0.05). CONCLUSIONS: PVP combined with I seed exhibited the best clinical efficacy in terms of VAS, PVP combined with RT was the best choice in terms of WHO Pain Relief, and PVP combined with RFA showed the best effect in terms of ODI for the treatment of SM.

Allicin protects against H2O2-induced apoptosis of PC12 cells via the mitochondrial pathway.

Allicin is a major bioactive ingredient of garlic and has a broad range of biological activities. Allicin has been reported to protect against cell apoptosis induced by H2O2 in human umbilical vein endothelial cells. The present study evaluated the neuroprotective effect of allicin on the H2O2-induced apoptosis of rat pheochromocytoma PC12 cells in vitro and explored the underlying mechanism involved. PC12 cells were incubated with increasing concentrations of allicin and the toxic effect of allicin was measured by MTT assay. The cells were pretreated for 24 h with low dose (L-), medium dose (M-) and high dose (H-) of allicin, followed by exposure to 200 µM H2O2 for 2 h, and the cell viability was examined by MTT assay. In addition, cell apoptosis rate was analyzed by Annexin V-FITC/PI assay, while intracellular reactive oxygen species (ROS) and mitochondrial transmembrane potential (∆ψm) were measured by flow cytometry. Bcl-2, Bax, cleaved-caspase-3 and cytochrome c (Cyt C) in the mitochondria were also examined by western blotting. The results demonstrated that 0.01 µg/ml (L-allicin), 0.1 µg/ml (M-allicin) and 1 µg/ml (H-allicin) were non-toxic doses of allicin. Furthermore, H2O2 reduced cell viability, promoted cell apoptosis, induced ROS production and decreased ∆ψm. However, allicin treatment reversed the effect of H2O2 in a dose-dependent manner. It was also observed that H2O2 exposure significantly decreased Bcl-2 and mitochondrial Cyt C, while it increased Bax and cleaved-caspase-3, which were attenuated by allicin pretreatment. The results revealed that allicin protected PC12 cells from H2O2-induced cell apoptosis via the mitochondrial pathway, suggesting the potential neuroprotective effect of allicin against neurological diseases.

Biocompatibility and fabrication of RGO/chitosan film for cartilage tissue recovery.

Graphene oxide (GO) has been successfully deoxygenated via an environmental friendly approach using chitosan. The prepared RGO was characterized using several microscopic and spectroscopic techniques. Also, the synthesized RGO is used to develop a highly compatible film with chitosan. Further, the in-vitro cytotoxicity results showed the biocompatible nature of prepared RGO/chitosan composite towards the human articular chondrocytes indicating their use in future cartilage tissue engineering applications.

Study of Double-level Degeneration of Lower Lumbar Spines by Finite Element Model.

BACKGROUND: Degeneration of intervertebral disks in the lower lumbar spine is associated with significant structural alterations. Finite element model has been widely used in the study of spinal mechanical behaviors. Our study used this technique to characterize the motional influence to the double-level (L4-5 and L5-S) degeneration. METHODS AND RESULTS: Three grades of disk degeneration were modeled with the changes in geometry and material properties. In the extension and flexion of range of motion (ROM), single segment degeneration in L4-5 or L5-S resulted in a decreased angle in itself and increased angle in the other segment. Double-level degeneration resulted in a decreased rotation in both segments. Bending resulted in a decreased ROM in all 3 grades of degeneration in the double-level degeneration. In torsion loading, mild and moderate single degeneration in L4-5 and L5-S increased the rotation angle. In double-level degeneration, mild and moderate L4-5 degeneration increased the L4-5 rotation angle by 14%-19%. In contrast, severe L4-5 decreased L4-5 rotation angle. Concurrently, mild and moderate L5-S degeneration increased the rotation angle, respectively, by 15% and 6%, and severe degeneration decreased the rotation angle by 29%. CONCLUSIONS: Different loading motions in double-level degeneration had differing effects on the ROM. These changes are important to understand the biomechanics of the progression of disk degeneration in the lower lumbar spine. Our results provide insights for the clinical intervention of double-level intervertebral disks.

Sex-pairing pheromone of Ancistrotermes dimorphus (Isoptera: Macrotermitinae).

Ancistrotermes dimorphus is a common Macrotermitinae representative, facultative inquiline by its life-style, occurring in South-East China. Sex pheromone is used for couple formation and maintenance, and it is produced by and released from the female sternal gland and is highly attractive to males. Based on our combined behavioral, chemical and electrophysiological analyses, we identified (3Z,6Z)-dodeca-3,6-dien-1-ol as the female sex pheromone of A. dimorphus as it evoked the tandem behavior at short distance, and the active quantities ranged from 0.01ng to 10ng. Interestingly, GC-MS analyses of SPME extracts showed another compound specific to the female sternal gland, (3Z)-dodec-3-en-1-ol, which showed a clear GC-EAD response. However, this compound has no behavioral function in natural concentrations (0.1ng), while higher amounts (1ng) inhibit the attraction achieved by (3Z,6Z)-dodeca-3,6-dien-1-ol. The function of (3Z)-dodec-3-en-1-ol is not fully understood, but might be linked to recognition from sympatric species using the same major compound, enhancing the long-distance attraction, or informing about presence of other colonies using the compound as a trail-following pheromone. The sternal gland secretion of Ancistrotermes females contains additional candidate compounds, namely (3E,6Z)-dodeca-3,6-dien-1-ol and (6Z)-dodec-6-en-1-ol, which are not perceived by males' antennae in biologically relevant amounts.

Neuroprotective effect of allicin in a rat model of acute spinal cord injury.

AIMS: This study aims to investigate the effect of allicin on motor functions and histopathologic changes after spinal cord injury and the mechanism underlying its neuroprotective effects. MAIN METHODS: The motor function of rats was evaluated with the Basso, Beattie, and Bresna test. Histopathologic changes were evaluated by hematoxylin and eosin and Nissl staining. Spinal cord oxidative stress markers were determined by measuring glutathione and malondialdehyde content and superoxide dismutase activity using commercial kits. Inflammatory factors were determined by measuring tumor necrosis factor-α, interleukin-1ß and interleukin-6 using ELISA assay. Apoptosis was examined using TUNEL staining. The effect of allicin on Nrf2 protein levels and localization was assessed using immunofluorescence staining and Western blotting analysis. KEY FINDINGS: Results demonstrated that allicin accelerated the motor functional recovery and protected neuron damage against spinal cord injury (SCI). SCI-induced oxidative stress, inflammatory response and cell apoptosis in the spinal cord were also prevented by allicin. In addition, we observed that SCI increased Nrf2 nuclear expression, and allicin treatment further increased Nrf2 nuclear translocation in neurons and astrocytes. siRNA-mediated Nrf2 gene knockdown completely blocked the effect of allicin on spinal cord tissue. SIGNIFICANCE: Our finding suggests that allicin promotes the recovery of motor function after SCI in rats, and this effect may be related to its anti-oxidant, anti-inflammatory and anti-apoptotic effects. Allicin mediated Nrf2 nuclear translocation may be involved in the protective effect as well.

MicroRNA-375 functions as a tumor suppressor in osteosarcoma by targeting PIK3CA.

Osteosarcoma has become one of the most common primary malignant bone tumors in childhood and adult. Numerous studies have demonstrated that aberrant microRNA (miRNA) expression is involved in human disease including cancer. To date, the potential miRNAs regulating osteosarcoma growth and progression are not fully identified yet. Herein, we showed that miR-375 was frequently downregulated in osteosarcoma tissue and cell lines compared to normal human colon tissues. Overexpression of miR-375 resulted in decreased expression of PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha) at both mRNA and protein levels. We found that miR-375 overexpression markedly suppressed cell proliferation in vitro. And inhibition of miR-375 promotes osteosarcoma growth. Mechanistic studies showed that PIK3CA was a potential target of miR-375 and it mediated reduction of PIK3CA resulted in suppression of PI3K/Akt pathway. Taken together, our results demonstrate that miR-375 functions as a growth-suppressive miRNA and plays an important role in inhibiting the tumorigenesis through targeting PIK3CA in osteosarcoma.

A Comparison of Anterior Cervical Corpectomy and Fusion Combined With Artificial Disc Replacement and Cage Fusion in Patients With Multilevel Cervical Spondylotic Myelopathy.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of this study was to compare clinical and radiological outcomes of anterior cervical corpectomy and fusion (ACCF) combined with artificial disc replacement (C-ADR) and ACCF combined with anterior cervical discectomy and fusion (ACDF) in patients with consecutive 3-level cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: The optimal surgical strategy for multilevel CSM (MCSM) remains undefined. C-ADR maintains motion at the level of the surgical procedure and decreases strain on the adjacent segments. The clinical results of multilevel C-ADR have not yet been elucidated. ACCF combined with 1-level C-ADR for the treatment of consecutive 3-level CSM may be a reasonable alternative to 3-level fusion. METHODS: We retrospectively reviewed the histories of patients who underwent surgery for consecutive 3-level CSM between C3-4 and C6-7 from June 2007 to August 2011. A total of 42 patients were divided into 2 groups. Group A (n = 19) underwent ACCF combined with 1-level C-ADR; group B (n = 23) underwent ACCF combined with 1-level ACDF. We compared perioperative parameters, clinical parameters, and radiological parameters. RESULTS: There were no significant differences in the average age, sex ratio, the preoperative heights of the disc space or average blood loss between the 2 groups. Group A had longer operation times than group B (P < 0.05). During the follow-up period, group A showed a better Neck Dysfunction Index recovery (P < 0.05) at 24 months postoperatively, and less visual analogue scale scores at 12 and 24 months postoperatively (P < 0.05 and P < 0.001, respectively). Moreover, group A exhibited better C2-C7 range of motion recovery at 6, 12, and 24 months postoperatively (P < 0.05, respectively). CONCLUSION: Group A was superior to Group B in terms of better Neck Dysfunction Index recovery, less intermediate term pain, and better C2-C7 ROM recovery. ACCF hybrid 1-level C-ADR may be a suitable choice for the management of 3-level CSM in appropriate patients. LEVEL OF EVIDENCE: 3.