PCSK9 inhibitors and osteoporosis: mendelian randomization and meta-analysis.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors represent an effective strategy for reducing cardiovascular disease risk. Yet, PCSK9's impact on osteoporosis remains unclear. Hence, we employed Mendelian randomization (MR) analysis for examining PCSK9 inhibitor effects on osteoporosis. METHODS: Single nucleotide polymorphisms (SNPs) for 3-hydroxy-3-methylglutaryl cofactor A reductase (HMGCR) and PCSK9 were gathered from available online databases for European pedigrees. Four osteoporosis-related genome-wide association studies (GWAS) data served as the main outcomes, and coronary artery disease (CAD) as a positive control for drug-targeted MR analyses. The results of MR analyses examined by sensitivity analyses were incorporated into a meta-analysis for examining causality between PCSK9 and HMGCR inhibitors and osteoporosis. RESULTS: The meta-analysis involving a total of 1,263,102 subjects, showed that PCSK9 inhibitors can increase osteoporosis risk (P < 0.05, I2, 39%). However, HMGCR inhibitors are not associated with osteoporosis risk. Additionally, a replication of the analysis was conducted with another exposure-related GWAS dataset, which led to similar conclusions. CONCLUSION: PCSK9 inhibitors increase osteoporosis risk. However, HMGCR inhibitors are unremarkably linked to osteoporosis.

Genetically predicted triglycerides mediate the relationship between type 2 diabetes Mellitus and intervertebral disc degeneration.

BACKGROUND: To validate the causal relationship between type 2 diabetes mellitus (T2DM) and intervertebral disc degeneration (IVDD) and to identify and quantify the role of triglycerides (TGs) as potential mediators. METHODS: A two-sample Mendelian randomization (MR) analyses of T2DM (61,714 cases and 1178 controls) and IVDD (20,001 cases and 164,682 controls) was performed using genome-wide association studies (GWAS). Moreover, two-step MR was employed to quantify the proportionate impact of TG-mediated T2DM on IVDD. RESULTS: MR analysis showed that T2DM increased IVDD risk (OR: 1.0466, 95% CI 1.0049-1.0899, P = 0.0278). Reverse MR analyses demonstrated that IVDD does not affect T2DM risk (P = 0.1393). The proportion of T2DM mediated through TG was 11.4% (95% CI 5.5%-17.4%). CONCLUSION: This work further validates the causality between T2DM and IVDD, with a part of the effect mediated by TG, but the greatest impacts of T2DM on IVDD remain unknown. Further studies are needed to identify other potential mediators.

Compare the clinical value of two minimally invasive approaches to locating radial nerve in the posterior humeral approach.

PURPOSE: To compare the clinical value between locating radial nerve (RN) guided by Color Doppler ultrasonography and posterior antebrachial cutaneous nerve (PACN) in the posterior humeral approach. METHODS: The five fresh adult cadavers (ten upper arms) were selected to compare the two methods of locating the RN in the posterior humeral approach (guided by ultrasound and PACN) by measuring the operation time, the length of incision, and the area of subcutaneous free. And the comparison between the two groups was statistically analyzed by paired t-test. RESULTS: The results of this study demonstrated that the length of incision and the area of subcutaneous free in the ultrasound group were smaller than that in the PACN group (P < 0.05), while the operation time was just the opposite (P < 0.05). However, after excluding the time of ultrasound location, the operation time in the ultrasound group was shorter than that in the PANC group, and the difference was statistically significant (P < 0.05). CONCLUSION: The RN can be quickly and safely exposed by both methods. The ultrasound approach requires a long learning curve, but is more minimally invasive and can help determine whether the intraoperative nerve is compressed by the plate. And the PACN method requires a longer incision and a wider area of subcutaneous free, while specialized equipment and professional training for surgeons are not required. In a word, these two methods have advantages and disadvantages, so they should be selected based on the exact situation.

A posterolateral sheared fracture of the tibial plateau: a case presentation.

BACKGROUND: Among tibial plateau fractures, one specialized type is the posterolateral column fracture. There are few published studies on posterolateral tibial plateau fractures with a sheared fragment that was wedged into the intercondylar fossa without the anterior cruciate ligament (ACL) rupture. According to our research, this case presentation is the first to describe in detail the treatment and long-term follow-up for this uncommon subtype of posterolateral tibial plateau fracture. CASE PRESENTATION: A 46-year-old female injured her right knee when she was riding a motorbike and was diagnosed with a posterolateral sheared tibial plateau fracture with a wedge-shaped fragment inserted into the femoral intercondylar fossa. The fracture was repaired with open reduction internal fixation surgery. The patient's recovery was followed for four years. The degree of healing as indicated by clinical and radiological examinations was substantial. The patient exhibited an excellent range of motion for the repaired knee (0-145°) and little discomfort. The Lysholm score was 96, the hospital for special surgery score was 98, the Rasmussen clinical assessment was 28, and the Rasmussen radiological assessment was 18. CONCLUSION: This study revealed that a posterolateral sheared tibial plateau, as seen in this case, can be reset and fixed sufficiently to achieve excellent long-term postoperative recovery.

Discovering Potential Mechanisms of Intervertebral Disc Disease Using Systematic Mendelian Randomization of Human Circulating Immunocytomics.

BACKGROUND: Although intervertebral disc degeneration (IVDD) is a critical factor in many spine-related diseases and has an extremely high prevalence in the aging population, the potential pathogenesis remains to be clarified entirely. Immune cells have been found to perform an essential function during the onset and progression of IVDD in recent years. Therefore, we explored the association between immune cell characteristics and IVDD through Mendelian randomization (MR) analysis and further delved into the mediating role of potential metabolites. METHODS: Based on the MR analysis, the association of 731 immune cell phenotypes and 1400 metabolites on IVDD were assessed. Single nucleotide polymorphisms were closely associated the expression levels of immune cell characteristics and the concentrations of metabolites and have been used as instrumental variables for deducing them as risk factors or protective factors for IVDD. In addition, mediation analyses have been performed to identify potential metabolite mediators between immune cell characteristics and IVDD. RESULTS: MR analysis identified 27 immune cell phenotypes and 79 metabolites significantly associated with IVDD. In addition, mediation analysis was performed by selecting the immune cell phenotype that most significantly increased the risk of IVDD - CD86 on monocytes. A total of 4 metabolite-mediated mediation relationships were revealed (3 b-hydroxy-5-cholenoic acid, X-22509, N-acetyl-L-glutamine, and N2-acetyl, N6, N6-dimethyllysine). CONCLUSIONS: The findings of this analysis identified underlying association between immune cell phenotypes, metabolite, and IVDD that may serve as predictive and prognostic clinical biomarkers and benefit IVDD pathogenesis research.

Therapeutic potential of single-nucleotide polymorphism-mediated IL6R inhibitors in ankylosing spondylitis treatment.

Objective: Interleukin-6 (IL-6) is a multiple-effect cell factor implicated in the etiopathogenesis of several rheumatologic disorders. The blockade of the IL-6 pathway via IL6R inhibitors effectively treats these disorders. However, the clinical significance of the IL6R blockade for ankylosing spondylitis (AS) therapy remains controversial. With advances in genomics, increasing evidence has revealed the role of heritability in the etiology of disease, and Mendelian randomization (MR) analyses are being used more broadly to infer causation. Therefore, this MR study aims to evaluate the potential therapeutic utility of IL6R-targeted approaches in AS. Methods: The C-reactive protein (CRP) level was used as an exposure factor, and rheumatoid arthritis (RA) was used as a positive control. As-related genome-wide association study (GWAS) data were used as the primary outcome of drug-targeted MR analyses to test the relation between IL6R blockers and AS. Inverse variance weighting (IVW) is the primary analytical approach. Various sensitivity tests were performed to check the robustness and trustworthiness of the causality estimation, including consistency, heterogeneity, and pleiotropy analyses. In addition, repeated analysis was conducted using different GWAS data related to exposures and outcomes to examine the results for stability. Results: According to the IVW results, IL6R inhibitors significantly reduced the risk of AS in ukb-b-18194 (OR: 0.995, 95% CI 0.993-0.996, P = 5.12 × 10-08) and ukb-a-88 (OR: 0.994, 95% CI 0.993-0.996, P = 6.25 × 10-15). Moreover, repeated analyses were performed using different exposure-related GWAS data, yielding similar results, ukb-b-18194 (OR: 0.995, 95% CI 0.993-0.997, P = 1.25 × 10-06) and ukb-a-88 (OR: 0.995, 95% CI 0.994-0.997, P = 7.81 × 10-09). Heterogeneity analyses and pleiotropy analyses indicated no significant heterogeneity or pleiotropy. Conclusion: This MR analysis result further validates that the IL-6 pathway may contribute to the pathogenesis of AS and that the inhibition of IL6R reduces the risk of AS. These findings may guide future studies and provide more favorable drug treatment options for people at high risk of AS.

A germline JAK2 exon12 mutation and a late somatic CALR mutation in a patient with essential thrombocythemia.

Background: It has been discovered that Janus kinase 2 (JAK2) exon12 mutations lead to the polycythemia vera (PV) phenotype, while somatic mutations of calreticulin (CALR) are associated with essential thrombocythemia (ET) or primary myelofibrosis. In this article, we report a case of ET with coexistence of JAK2 exon12 and CALR mutations. The objective of this study was to elucidate the pathogenicity mechanism of a JAK2 exon12 mutation (JAK2N533S) and the role of the coexistence of mutations on the hematological phenotype. Methods: We designed a colony analysis of tumor cells obtained from this patient, and attempted to identify mutant genes using DNA from hair follicles. Mutation impairment prediction and conservative analysis were conducted to predict the mutation impairment and structure of JAK2N533S. In addition, we conducted a functional analysis of JAK2N533S by constructing Ba/F3 cell models. Results: Three distinct tumor subclones, namely JAK2N533Shet+/CALRtype1het +, JAK2N533Shet+/CALR wt, and JAK2N533Shet+/CALRtype1hom +, were identified from the 17 selected erythroid and 21 selected granulocyte colonies. The analysis of hair follicles yielded positive results for JAK2N533S. According to the bioinformatics analysis, JAK2N533S may exert only a minor effect on protein function. Functional studies showed that JAK2N533S did not have a significant effect on the proliferation of Ba/F3 cells in the absence of interleukin-3 (IL-3), similar to wild-type JAK2. Notably, there were no increased phosphorylation levels of JAK2-downstream signaling proteins, including signal transducer and activator of transcription 3 (STAT3) and STAT5, in Ba/F3 cells harboring the JAK2N533S. Conclusion: Our study revealed that the JAK2N533Shet+/CALRtype1het+ subclone was linked to a significant expansion advantage in this patient, indicating that it may contribute to the development of the ET phenotype. We further demonstrated that JAK2N533S, as a noncanonical JAK2 exon12 mutation, is a germline mutation that may not exert an effect on cell proliferation and protein function. These results and the present body of available data imply that certain noncanonical JAK2 mutations are not gain-of-function mutations leading to the development of myeloproliferative neoplasms.

Balancing Public & Economic Health in Japan during the COVID-19 Pandemic: A Descriptive Analysis.

Despite loose restrictions and a low mortality rate due to COVID-19, Japan faced the challenge of stabilizing its economy during the pandemic. Here, we analyzed how the Japanese government attempted to maintain a balance between the health of the population and the health of the economy. We used a mix of quantitative data, information from policy documents, and news agency publications. Features of the Japanese government's handling of the pandemic include the lack of constitutional authority to enforce a lockdown, the laxer restrictions compared with other countries in which citizens were advised only to exercise self-restraint and avoid close social contact, and the existence of expert panels that had only an advisory role. Our findings address the slow initial response of the government, which feared that the 2020 Tokyo Olympics would be canceled, and the increased testing when the Olympics were postponed, as well as the expansion of vaccination efforts after the Olympics. In addition, there was a targeted campaign to promote national travel to increase economic revenue in the tourism sector, but this led to an increase in COVID-19 cases.

Identification of the circRNA-miRNA-mRNA regulatory network in osteoarthritis using bioinformatics analysis.

Background: Osteoarthritis (OA) is a degenerative joint disease that seriously affects the quality of people. Unfortunately, the pathogenesis of OA has not been fully known. Therefore, this study aimed to construct a ceRNA regulatory network related to OA to explore the pathogenesis of OA. Methods: Differentially expressed circRNAs (DEcircRNAs), microRNAs (DEmiRNAs), and mRNAs (DEmRNAs) were obtained from the Gene Expression Omnibus microarray data (GSE175959, GSE105027, and GSE169077). The miRNA response elements and target mRNAs were identified using bioinformatics approaches. Additionally, a circRNA-miRNA-mRNA network was established using Cytoscape version 3.8.0. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of mRNAs in the network were conducted to explore the possible mechanisms underlying OA development. Protein-protein interaction (PPI) analysis was performed to determine the hub genes. Based on the hub genes, a sub network was constructed using Cytoscape 3.8.0 version. Finally, connectivity map (CMap) and drug-gene interaction database (DGIdb) analyses were performed to identify the potential therapeutic targets for OA. Results: Altogether, five DEcircRNAs, 89 DEmiRNAs, and 345 DEmRNAs were identified. Moreover, a circRNA-miRNA-mRNA network was established using three circRNAs, seven miRNAs, and 37 mRNAs. GO and KEGG analyses demonstrated that the mRNAs in the network could be related to the occurrence and development of OA. PPI analysis was performed and six key genes, namely serpin family H member 1 [SERPINH1], collagen type VIII alpha 2 chain [COL8A2], collagen type XV alpha 1 chain [COL15A1], collagen type VI alpha 3 chain [COL6A3], collagen type V alpha 1 chain [COL5A1], and collagen type XI alpha 1 chain [COL11A1], were identified. Furthermore, a circRNA-miRNA-hub gene subnetwork was established in accordance with two circRNAs (hsa_circ_0075320 and hsa_circ_0051428), two miRNAs (hsa-miR-6124 and hsa-miR-1207-5p), and six hub genes (COL11A1, SERPINH1, COL6A3, COL5A1, COL8A2, and COL15A1). Finally, three chemicals (noscapine, diazepam, and TG100-115) based on CMap analysis and two drugs (collagenase Clostridium histolyticum and ocriplasmin) based on DGIdb were discovered as potential treatment options for OA. Conclusion: This study presents novel perspectives on the pathogenesis and treatment of OA based on circRNA-related competitive endogenous RNA regulatory networks.

The gut microbiome and antibiotic resistome of chronic diarrhea rhesus macaques (Macaca mulatta) and its similarity to the human gut microbiome.

BACKGROUND: Chronic diarrhea is a common disease causing morbidity and mortality of captive rhesus macaques (RMs, Macaca mulatta). Chronic diarrhea in RMs is typically characterized by long-term diarrhea and a weak response to antibiotic treatment. Diarrhea is also a common disease in humans and can cause death. However, the etiology of about half of diarrheal cases of humans is still unclear. Therefore, we performed shotgun metagenomic sequencing to characterize the differences in the gut microbiome and resistome of chronic diarrhea RMs and asymptomatic individuals. RESULTS: Our results showed Lactobacillus spp. (mainly L. johnsonii, L. reuteri and L. amylovorus) were significantly depleted in chronic diarrhea RM guts compared to asymptomatic individuals (5.2 vs 42.4%). Functional annotation of genes suggested these Lactobacillus spp. carried genes involved in the adhesion of intestinal epithelial cells and production of bacteriocin. Chronic diarrhea RM guts also had a significantly greater abundance of many other gut bacteria, including mucin-degrading bacteria and opportunistic pathogens. The metabolic pathways of chronic diarrhea RM gut microbiome were enriched in aerobactin biosynthesis, while the metabolic pathways of asymptomatic RM gut microbiome were enriched in the production of short-chain fatty acids (SCFAs). Chronic diarrhea RM guts had a significantly greater abundance of antibiotic resistance genes (ARGs), such as ermF, aph(3')-IIIa, ermB, and floR. The strains isolated from feces and tissue fluid of chronic diarrhea RMs had higher resistance rates to the majority of tested antibiotics, but not cephamycin and carbapenem antibiotics. Gut microbial composition comparisons showed that several captive nonhuman primate (NHP) guts were more similar to the guts of humans with a non-westernized diet than humans with a westernized diet. Chronic diarrhea RM gut microbiome was strikingly similar to rural-living humans with diarrhea and humans with a non-westernized diet than asymptomatic RMs. CONCLUSIONS: Our results suggested chronic diarrhea significantly altered the composition and metabolic pathways of the RM gut microbiome. The frequent use of antibiotics caused antibiotic resistance in chronic diarrhea RM gut microbiome with serious consequences for individual treatment and survival. The findings of this study will help us to improve the effective prevention and treatment of diarrhea in RMs. Video Abstract.

circSKIL promotes the ossification of cervical posterior longitudinal ligament by activating the JNK/STAT3 pathway.

Ossification of the posterior longitudinal ligament (OPLL) is a hyperostotic spinal condition that involves genetic factors as well as non-genetic factors, and its underlying molecular mechanism is largely unknown. Recently, circular RNAs (circRNAs) have been attracting the attention of researchers since they have important regulatory roles in many diseases, including bone metabolism disorders. The present study aimed to investigate the role of circRNA SKI-like proto-oncogene (circSKIL) in OPLL disease progression. First, primary posterior longitudinal ligament cells from patients with cervical spondylotic myelopathy (CSM) without OPLL (control group) and CSM patients with OPLL (OPLL group) were isolated, and the expression levels of circSKIL in ligament cells was found to be significantly increased in the OPLL group compared with control. This result was also confirmed in OPLL tissues. Next, circSKIL was overexpressed in control ligament cells, and the proliferation, mineralization, and osteogenic differentiation of ligament cells were found to be significantly enhanced; the phosphorylation levels of both JNK and STAT3 were upregulated. By contrast, the knockdown of circSKIL in OPLL ligament cells inhibited proliferation, mineralization, and osteogenic differentiation and inactivated the JNK/STAT3 pathway. Therefore, circSKIL may have a significant role in osteogenic differentiation and could serve as a potential target to prevent OPLL progression.

High neural precursor cell-expressed developmentally down-regulated 9 expression is a poor prognostic indicator for osteosarcoma.

BACKGROUND: This study detected neural precursor cell-expressed developmentally down-regulated 9 (NEDD9) expression in osteosarcoma tissue samples. It also examined the association between NEDD9 expression and clinicopathological features of osteosarcoma. METHODS: The prognostic value of NEDD9 has been verified in multiple solid cancers, but not osteosarcoma. In this study, 45 osteosarcoma paraffin-embedded specimens were accumulated and applied based on immunohistochemistry to identify NEDD9 expression. A correlation linking NEDD9 expression, clinicopathological qualities, and its prognostic significance was assessed to verify whether NEDD9 could be a poor prognosis biomarker. RESULTS: High NEDD9 expression compared to its low expression in osteosarcoma tissue was shown in the immunohistochemical assay. The percentage of high and low NEDD9 expression was 62.2% and 37.8% respectively. NEDD9 expression level was significantly associated with metastasis and Enneking stage (P<0.05), while gender, age, tumor size, sites, and histopathological types were not. Univariate analysis showed that metastasis with a hazard ratio (HR) of 2.63 (P=0.003), Enneking stage III (HR =5.44, P=0.009), chondroblastic osteosarcoma (HR =2.59, P=0.014), and high NEDD9 expression (HR =2.79, P=0.002) were prognostic factors contributing to poor overall survival (OS). Moreover, multivariate analysis revealed that nonconventional pathological osteosarcoma (HR =0.17, P=0.010) and NEDD9 expression (HR =6.03, P<0.001) were independent prognostic factors. CONCLUSIONS: High NEDD9 expression in osteosarcoma independently indicated poor clinical prognosis, indicating the possibility that NEDD9 could be a therapeutic target for osteosarcoma.

Upregulated miR-96-5p inhibits cell proliferation by targeting HBEGF in T-cell acute lymphoblastic leukemia cell line.

INTRODUCTION: microRNAs (miRNAs) are critical for tumorigenesis and progression of T-cell acute lymphoblastic leukemia (T-ALL). MiR-96-5p has been shown to play important roles in the development of many cancers, but its roles in T-ALL have yet not been studied. MATERIALS AND METHODS: miR-96-5p expression was detected in T-leukemic cells from peripheral blood of 30 patients with T-ALL using real-time quantitative PCR (RT-qPCR). TargetScan database was utilized to identify the target genes for miR-96-5p, and their target relationship was verified by western blot, dual luciferase reporter assay and RT-qPCR. The effects of miR-96-5p on the viability and proliferation of T-leukemic cells (Jurkat cells) were respectively determined using MTT and BrdU incorporation assays. RESULTS: miR-96-5p presented low expression levels by qPCR in peripheral blood of T-ALL patients compared to healthy volunteers. Upregulated miR-96-5p by miR-96-5p mimic transfection markedly inhibited the viability and proliferation of Jurkat cells. Furthermore, miR-96-5p negatively regulated the expression of its target gene, HBEGF. The decreased viability and proliferation of Jurkat cells caused by miR-96-5p over-expression was suppressed after the introduction of HBEGF plasmid. CONCLUSIONS: The presented study showed that upregulation of miR-96-5p inhibited the viability and proliferation of Jurkat T-leukemic cells through suppressing HBEGF expression. Our study provides a novel sight for understanding the pathological mechanism of T-ALL and suggests that miR-96-5p may be a potential biomarker for the therapy and diagnosis of T-ALL.

TREX1 suppression imparts cancer-stem-cell-like characteristics to CD133- osteosarcoma cells through the activation of E2F4 signaling.

There is ongoing debate whether cancer stem cells (CSCs) could arise from the transformation of non-CSCs under specific conditions. In the present study, the role of the three prime repair exonuclease 1 (TREX1) in regulating CSC generation form human osteosarcoma cells was investigated. High, intermediate and low levels of TREX1 expression were respectively observed in low-grade, high-grade and metastatic human osteosarcoma samples, while the opposite tendency was observed for E2F4, a transcription factor associated with G2 arrest. Luciferase assay proved that TREX1 had a negative impact on the activity of E2F4 promoter. TREX1 was highly expressed in CD133- HOS cells (non-CSC osteosarcoma cells) compared to CD133+ ones; whereas TREX1 knockdown endowed the CD133- non-CSCs with CSC-like characteristics in vitro relying on E2F4 activation, as demonstrated by enlarged proportion of the subset expressing CSC markers in flow cytometry analysis, enhanced self-renewal ability in osteosphere formation assay, increased metastasis capacity in migration and invasion assays, together with improved chemoresistance to cisplatin. Furthermore, TREX1 knockdown and subsequent E2F4 activation could promote the tumorigenicity of CD133- non-CSCs in vivo. With respect to underlying mechanisms, it was found that in CD133- HOS cells, TREX1 suppression would allow the activation of ß-catenin signaling in the dependence of E2F4, thus possibly leading to the up-regulation of the transcription factor OCT4. These findings suggested that TREX1 was probably a negative regulator of CSC formation and hence worth to be further studied for developing new treatments in cancer therapies targeting CSCs.

Gene expression profiling of brain metastatic cell from triple negative breast cancer: Understanding the molecular events.

Brain metastatic triple negative breast cancer (BM-TNBC) is afflicted with unfavorable prognosis. However, the molecular events underlying BM-TNBC remain largely unknown. In the present study, we conducted gene expression microarray analysis using the triple negative breast cancer cell line MDA-MB-231 and its brain metastatic derivative (MDA-MB-231Brm). Results of microarray analysis showed that a total of 4296 genes were differentially expressed, of which 2433 genes were up-regulated and 1863 genes were down-regulated. Gene Ontology (GO), KEGG pathway and protein-protein interaction (PPI) analyses indicated differentially expressed genes functionally categorized as genes of signal transduction, multicellular organismal development, ion transport, nervous system development, plasma membrane, extracellular region, calcium ion binding, GTP binding neuroactive ligand-receptor interaction. The validity of the microarray results was verified by quantitative real-time PCR analysis of twelve representative genes. The present findings revealed molecular basis and events associated with brain metastasis in TNBC, which will potentially contribute to the understanding of underlying mechanism and develop therapeutic targets.

Feasibility of interlaminar lumbar discectomy through percutaneous transforaminal endoscopy and blunt perforation of the ligamentum flavum.

AIM: To determine the efficacy, safety, and clinical value of a novel surgical procedure involving the blunt perforation of the ligamentum flavum (LF) during endoscopic interlaminar lumbar discectomy. MATERIAL AND METHODS: This was a prospective study of 50 patients (27 males, 17-51 years of age) undergoing lumbar discectomy for single segment L4/L5 or L5/S1 disk herniation were grouped into the control (cutting of the LF; n=28) and test (blunt perforation; n=22) groups. Intraoperative injury to the LF was evaluated by electrophysiological monitoring. The time required for perforation, total surgical time, and proportion of epidural sac and nerve root injury were assessed. RESULTS: Among the enrolled patients, 90% showed herniation of the L4/5 segment and 10% of the L5/S1 segment. The success rate for the perforation of the LF was 93%. The intraoperative observation showed mild self-closing injury to the LF tissue. The test group showed shorter overall surgical time (43 vs. 56 min) and shorter duration to go through the LF (1 vs. 13 min, p 0.001). No dural sac or nerve root injury resulting from blunt perforation of the LF was observed. CONCLUSION: Compared to cutting, blunt perforation of the LF could reduce surgical time and injury to LF and surrounding tissues. Thus, it could be a safe and efficient surgical technique for patients undergoing intralaminar lumbar discectomy.

Transdifferentiation of human MNNG/HOS osteosarcoma cells into vascular endothelial cells in vitro and in vivo.

The transdifferentiation of cancer cells into other types of cells in several types of tissues or organs has been studied. However, whether human osteosarcoma MNNG/HOS cells can transdifferentiate into other types of cells has seldom been reported. Meanwhile, the mechanism of tumor angiogenesis is still disputed, and whether MNNG/HOS cells participate in angiogenesis in osteosarcoma remains unknown. In the present study, the investigation was divided into two parts: in vitro and in vivo. In vitro, we cultivated MNNG/HOS cells under hypoxic conditions for 4 days and found that they typically showed a characteristic 'flagstone' appearance as cultured vascular endothelial cells (VECs). MNNG/HOS cells that were cultivated on Matrigel under hypoxic conditions gradually formed tubular-like structures. Furthermore, when cultured under hypoxic conditions for 4 days, MNNG/HOS cells also transcribed and expressed several molecular markers of VECs (CD31, CD34 and vWF). In vivo, MNNG/HOS cells (1x106 cells) were cultivated under hypoxic conditions and subcutaneously injected into nude mice; the mice were sacrificed 49 days after inoculation. Immunohistochemical staining with anti-human CD31 antibody showed evidence of tumor angiogenesis in human osteosarcoma MNNG/HOS cells. The results demonstrated that MNNG/HOS cells can transdifferentiate into vascular endothelial cell-like cells in vitro and in vivo.

Verification of TREX1 as a promising indicator of judging the prognosis of osteosarcoma.

BACKGROUND: The study aimed to explore the correlation between the expression of TREX1 and the metastasis and the survival time of patients with osteosarcoma as well as biological characteristics of osteosarcoma cells for the prognosis judgment of osteosarcoma. METHOD: The correlation between the expression of TREX1 protein and the occurrence of pulmonary metastasis in 45 cases of osteosarcoma was analyzed. The CD133+ and CD133- cell subsets of osteosarcoma stem cells were sorted by the flow cytometry. The tumorsphere culture, clone formation, growth curve, osteogenic and adipogenic differentiation, tumor-formation ability in nude mice, sensitivity of chemotherapeutic drugs, and other cytobiology behaviors were compared between the cell subsets in two groups; the expressions of stem cell-related genes Nanog and Oct4 were compared; The expressions of TREX1 protein and mRNA were compared between the cell subsets in two groups. The data was statistically analyzed. The measurement data between the two groups were compared using t test. The count data between the two groups were compared using χ 2 test and Kaplan-Meier survival analysis. A P value <0.05 indicated that the difference was statistically significant. RESULTS: The expression of TREX1 protein in patients with osteosarcoma in the metastasis group was significantly lower than that in the non-metastasis group. The difference was statistically significant (P < 0.05). Up to the last follow-up visit, the former average survival time was significantly lower than that of the latter, and the difference was statistically significant (P < 0.05). The expression of TREX1 in human osteosarcoma CD133+ cell subsets was significantly lower than that in CD133- cell subsets. Stemness-related genes Nanog and Oct4 were highly expressed in human osteosarcoma CD133+ cell subsets with lower expression of TREX1; the biological characteristics identification experiment showed that human CD133+ cell subsets with low TREX1 expression could form tumorspheres, the number of colony forming was more, the cell proliferation ability was strong, the osteogenic and adipogenic differentiation potential was big, the tumor-forming ability in nude mice was strong, and the sensibility of chemotherapeutics drugs on cisplatin was low. CONCLUSIONS: The expression of TREX1 may be related to metastasis in patients with osteosarcoma. The expression of TREX1 was closely related to the cytobiology characteristics of osteosarcoma stem cell. TREX1 can play an important role in the occurrence and development processes. And, TREX1 is expected to become an effective new index for the evaluation of the prognosis.

Matrine and CYC116 synergistically inhibit growth and induce apoptosis in multiple myeloma cells.

OBJECTIVE: To investigate whether CYC116 can potentiate matrine-dependent growth inhibition and apoptosis in multiple myeloma (MM) cells. METHODS: The dose response relationship of matrine to dexamethasone-resistant and dexamethasone-sensitive MM cells was first established. Myeloma RPMI8226 cells were treated with matrine alone or combined with CYC116 for 24 h. Cell proliferation was measured using an MTT assay and apoptosis induction was evaluated by flow cytometry. Activation of the caspase pathway and expression of apoptosis regulator proteins were detected by Western blotting. RESULTS: Matrine significantly induced growth arrest and apoptosis in both drug-resistant and drug-sensitive MM cells. Treatment with the combination of matrine and CYC116 had a stronger cytotoxic effect on MM cells than did single drug treatments. Enhanced apoptosis observed following the combined treatment of matrine and CYC116 was associated with higher levels of activation of caspase-9, caspase-3, and poly adenosine diphosphate ribose polymerase (PARP) and down-regulation of the anti-apoptotic proteins Bcl-2 and Mcl-1 and the signaling proteins p-Akt and nuclear factor κB (NF-κB). CONCLUSION: CYC116 enhances the growth inhibitory and apoptotic effects of matrine on MM cells.