Identification of a Good-Prognosis IDH-Mutant-Like Population of Patients with Diffuse Gliomas

BACKGROUND

Isocitrate dehydrogenase (IDH) mutation is the initiating event that defines major clinical and prognostic classes of gliomas, but the potential mechanisms have not been well interpreted yet. The main objective of the current study was to better understand the underlying biology of IDH mutant gliomas as captured by gene expression profiles.

METHODS

RNA sequencing data of WHO grade II-IV gliomas from the Chinese Glioma Genome Atlas (CGGA, N=325) were used to assess differentially expressed genes between IDH mutant and wild type gliomas and to construct a gene expression-based classifier to detect IDH mutant samples with high sensitivity and specificity. The classifier was validated in independent RNA sequencing data from the Cancer Genome Atlas (TCGA, N=699), and the prognostic value of the classifier was also assessed in the two datasets.

RESULTS

A 58-gene-pair IDH mutation signature was developed by using the top scoring pairs algorithm. In CGGA dataset, 98.5% and 100% IDH mutant samples were also predicted to be mutant by gene expression based IDH status in grade II-III and grade IV gliomas, respectively. In TCGA dataset, the proportions were 99.8% and 100%, respectively. The signature remained to be a prognostic marker in multivariate cox analysis both in CGGA and TCGA datasets.

CONCLUSION

A characteristic gene expression signature is associated with and accurately predicts IDH mutation status. This suggests a common biology between these tumors and adds prognostic and biologic information that is not captured by the mutation status alone. These results may help in population stratification for clinical trials. As RNA-seq is more and more prevalent and cost-effective in glioma molecular diagnosis, this gene signature would provide a precise method to predict IDH mutation status with RNA-seq data.

[Gastrectomy with either wedge resection of the pancreas or pancreaticosplenectomy for adenocarcinoma of the esophagogastric junction invading the pancreas: a comparison study]

Objective: To compare the outcomes of gastrectomy with either wedge resection of the pancreas or pancreaticosplenectomy for adenocarcinoma of the esophagogastric junction (AEG) invading pancreas. Methods: From May 2005 to December 2015, a total of 64 patients with AEG invading pancreas underwent gastrectomy with either wedge resection of pancreas (n=25) or pancreaticosplenectomy (n=39) at Department of Thoracic Surgery, Fourth Hospital, Hebei Medical University. There were 53 males and 11 females, with a mean age of 60.2 years (range: 39 to 77 years). According to the AJCC esophageal cancer staging system, 8(th) edition, there were 27 patients in phase T4N0M0, 18 in phase T4bN1M0, 9 in phase T4bN2M0 and 10 in phase T4bN3M0. Follow-up was carried out every 6 months. The t-test for the measurement data and the χ(2) test, Fisher exact test or Wilcoxon ran-sum test for the enumeration data were used between the two groups. Survival curves were generated using the Kaplan-Meier method, and compared using the Log-rank test. Multivariate analysis was undertaken using the Cox proportional hazard model (forward stepwise regression). Results: In 39 patients who underwent pancreaticosplenectomy, incision infection occurred in 5 patients, anastomotic leak, peritoneal infection, lung infarction each occurred in 1 patient. There was 1 respiratory failure and 1 peritoneal infection in 25 patients undergoing wedge resection of the pancreas. There were no significant difference in the incidence of postoperative complications between the 2 groups (8/39 vs. 2/25, P=0.292), and no postoperative death in the study. Fifty-seven patients were followed up, with a follow-up rate of 89.1%. The 5-year overall survival rate was 32.3% in patients who underwent simultaneous gastrectomy and pancreaticosplenectomy, compared to 0 in those who underwent gastrectomy and wedge resection of the pancreas (χ(2)=4.484, P=0.034). The 5-year overall survival rate for patients who undergoing adjuvant chemotherapy was 32.3%, compared to 17.2% in whom underwent surgery alone (χ(2)=4.186, P=0.041). Conclusions: Survival benefit from R0 resection by simultaneous gastrectomy and pancreaticosplenectomy for AEG invading the pancreas can be achieved. Adjuvant chemotherapy is necessary for these patients.

Proton migration in hydrocarbons induced by slow highly charged ion impact

Different from most of the previous studies using light or photons, we use highly charged ions as projectiles to activate proton migration in the smallest saturated and unsaturated hydrocarbon molecules, i.e., CH₄ and C₂H₂. The H₃ ⁺ formation channel (H₃ ⁺ + CH⁺) and isomerization channel (C⁺ + CH₂ ⁺), serving as indicators of proton migration, are observed in the fragmentation of CH₄ and C₂H₂ dications. Corresponding kinematical information, i.e., kinetic energy release, is for the first time obtained in the collisions with highly charged ions. In particular, for the C⁺ + CH₂ ⁺ channel, a new pathway is identified, which is tentatively attributed to the isomerization on high-lying states of acetylene dication. The kinetic energy release spectra for other two-body breakup channels are also determined and precursor dication states could thus be identified.

Analysis of differentially co-expressed genes based on microarray data of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer related death worldwide. Although great progress in diagnosis and management of HCC have been made, the exact molecular mechanisms remain poorly understood. The study aims to identify potential biomarkers for HCC progression, mainly at transcription level. In this study, chip data GSE 29721 was utilized, which contains 10 HCC samples and 10 normal adjacent tissue samples. Differentially expressed genes (DEGs) between two sample types were selected by t-test method. Following, the differentially co-expressed genes (DCGs) and differentially co-expressed Links (DCLs) were identified by DCGL package in R with the threshold of q < 0.25. Afterwards, pathway enrichment analysis of the DCGs was carried out by DAVID. Then, DCLs were mapped to TRANSFAC database to reveal associations between relevant transcriptional factors (TFs) and their target genes. Quantitative real-time RT-PCR was performed for TFs or genes of interest. As a result, a total of 388 DCGs and 35,771 DCLs were obtained. The predominant pathways enriched by these genes were Cytokine-cytokine receptor interaction, ECM-receptor interaction and TGF-β signaling pathway. Three TF-target interactions, LEF1-NCAM1, EGR1-FN1 and FOS-MT2A were predicted. Compared with control, expressions of the TF genes EGR1, FOS and ETS2 were all up-regulated in the HCC cell line, HepG2; while LEF1 was down-regulated. Except NCAM1, all the target genes were up-regulated in HepG2. Our findings suggest these TFs and genes might play important roles in the pathogenesis of HCC and may be used as therapeutic targets for HCC management.

A theoretical study of Ar8+-acetylene collisions at 1.2 MeV: Ionization and dissociation dynamics

We theoretically study Ar⁸⁺-induced dissociation of C₂H₂ molecule at 1.2 MeV using the time-dependent density-functional theory non-adiabatically coupled to nuclear dynamics. We find that molecular dissociation depends strongly on the ionization at the initial stage and the collision configuration. A detailed analysis shows a correspondence between the charge state of [C₂H₂]^q+ and the final fragments. A remarkable impact parameter effect provides deep insights of bond breakup and electronic transport. We analyze two typical sequential dissociation channels reported in experiments by tracking structural and electronic dynamics in real time. Our results provide better understanding of experiments. Moreover, the comparison between various exchange-correlation functionals reveals that electrons' correlation and self-interaction do not significantly impact the initial ionization and fragment distribution in the present study.

[Effects of artesunate combined with bortezomib on apoptosis and autophagy of acute myeloid leukemia cells in vitro and its mechanism]

Objective: To investigate the effects of artesunate combined with bortezomib on the proliferation, apoptosis and autophagy of human acute myeloid leukemia cell lines MV4-11, and its mechanisms. Methods: MTT method was used to determine the anti-proliferation effect of different concentrations of artesunate, bortezomib and their combination on MV4-11 cells. The cell apoptosis were analyzed by flow cytometry. The expression of cleaved-Caspase-3, Bcl-2 family protein (Bcl-2, Mcl-1, Bim, Bax) and autophagy-related protein LC3B were assayed by Western blot. Results: Artesunate displayed a proliferation inhibition effect on MV4-11 with dose- and time-dependent manner, the IC(50) of artesunate on MV4-11 after 48 hours was 1.44 μg/ml. Bortezomib displayed a proliferation inhibition effect on MV4-11 with dose-dependent manner, the IC(50) of bortezomib on MV4-11 after 48 hours was 8.97 nmol/L. The combination of artesunate (0.75, 1.0 μg/ml) and Bortezomib (6, 8 nmol/L) showed higher inhibition on MV4-11 than artesunate or bortezomib alone in the same concentration gradient after 48 hours (P<0.05) . The cooperation index of the two drugs were all less than 1. The 48 h apoptotic rate of artesunate (1.5 μg/ml) on MV4-11 was (15.27±2.18) %, (19.85±3.23) % of bortezomib (8 nmol/L) , (81.67±5.96) % of combination of the two drugs, significantly higher than the single group (P<0.05) . When combination of the two drugs on MV4-11 after 24 hours, the levels of pro-apoptotic protein Bim and the cleaved activation of Caspase-3 and autophagy-related protein LC3B were up-regulated and the anti-apoptotic protein Bcl-2 expressions was down-regulated. Conclusion: Combination of artesunate with bortezomib shows a significant synergistic effects on proliferation, apoptosis and autophagy of MV4-11 cell lines, which may be associated with Bcl-2 family proteins expression.

Imaging features of metanephric adenoma and their pathological correlation

AIM

To analyse the imaging features of metanephric adenoma (MA) and their pathological correlation.

MATERIALS AND METHODS

The imaging findings in 11 patients with MA were studied retrospectively. Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) findings were studied in seven, 11, and six patients, respectively. The enhancement pattern, attenuation, lesion location, size, cystic or solid appearance, capsule sign, and presence of calcifications were evaluated.

RESULTS

On ultrasonography, MA presented as hypoechoic (4/7), slightly hyperechoic (1/7), isoechoic (2/7), and with a clear boundary. Unenhanced CT showed unclear boundaries (11/11), homogeneous isodensity (8/11), with calcification (1/11), necrosis (1/11), and heterogeneous hyperattenuation (1/11). Mean CT attenuation values on unenhanced and enhanced CT (cortical phase, corticomedullary phase, and excretory phase) were 38.87±6.66, 55.71±17.74, 67.77±16.86, and 65.62±15.99 HU, respectively. The degree of enhancement of the lesions in each phase was statistically significantly lower than that of the surrounding normal renal parenchyma (p=0.00). The pattern of enhancement of the solid component was slight and gradual enhancement (9/11). The tumour was located entirely within the renal medulla in nine cases, and two cases demonstrated an exophytic pattern. All tumours showed a clear boundary on enhanced CT, but capsules were not found. The mean greatest tumour diameter was 3.5 cm. MA showed markedly hyperintense on the diffusion-weighted MRI sequence (DWI) and delayed enhancement of the tumour capsule on enhanced MRI.

CONCLUSIONS

Imaging features of MA are usually solid and hypovascular, and show prolonged, and homogeneous mild enhancement that is less than that of the surrounding normal renal parenchyma in all phases. MA is markedly hyperintense on DWI.

A reversed approach for simultaneous mandibular symphyseal split osteotomy and genioplasty

Performing a mandibular symphyseal split and genioplasty simultaneously and accurately is a technical challenge for the surgeon. The aim of this study was to validate a reversed approach for simultaneous symphyseal split and genioplasty. A cutting guide and a repositioning guide were designed and printed three-dimensionally in titanium. The symphyseal split and genioplasty were performed successfully. The accuracy of the technique appears to be appropriate for clinical application.

[miR-449a is a potential epigenetic biomarker for WNT subtype of medulloblastoma]

Objective: To identify the candidate epigenetic biomarkers of Wnt subtype of medulloblastoma(MB). Methods: MicroRNAs(miRNAs) expression array was used to detect the expression of miRNAs in MB cell lines with or without treatment by demethylation reagent. Nanostring gene expression array was used to detect the expression level of mRNA in 45 samples of primary MB. Molecular subtyping was performed based on the NanoString data. The status of methylation was confirmed by methylation specific PCR. The expression of candidate miRNA was confirmed by real-time PCR. Results: All 45 MBs except one were classified into the four molecular groups: 4 in WNT group, 8 in SHH group, 16 were in Group3 and 16 in Group4. Methylation specific PCR (MSP) assay confirmed miR-449a was silenced due to aberrant DNA methylation in MB cell lines.WNT subtype of MBs showed relatively higher expression of miR-449a comparing with other subgroups. Conclusion: MiR-449a, a candidate tumor suppressor gene regulated by hypermethylation, is a novel potential epigenetic marker for WNT subtype of MBs.

Post-traumatic stress disorder and incident fractures in the Danish population

Psychological stress may be associated with increased risk of fractures. It is unknown whether post-traumatic stress disorder (PTSD), a marker of chronic severe psychological stress occurring in response to a traumatic event, influences fracture risk. In this nationwide cohort study, persons with PTSD had an increased risk of fractures compared to the general population.

INTRODUCTION

We conducted a population-based national cohort study in Denmark to examine the association between PTSD and incident fractures.

METHODS

We examined the incidence rate of overall and specific fractures among patients with clinician-diagnosed PTSD (n = 4114), compared with the incidence rate in the general population from 1995 to 2013, using Danish medical registry data. We further examined differences in associations by gender, age, psychiatric and somatic comorbidity, and follow-up time. We calculated absolute risks, standardized incidence ratios (SIRs), and 95% confidence intervals (95% CIs).

RESULTS

Risk of any fracture among persons with PTSD was 24% (95% CI 20%, 28%) over the study period. The SIR for any fracture was 1.7 (95% CI 1.6, 1.9). We found little evidence of effect measure modification of the association between PTSD and fractures in our stratified analyses.

CONCLUSIONS

Our findings suggest that PTSD is associated with increased fracture risk.

[Identification of the Disease-Associated Genes in Periodontitis Using the Co-expression Network]

The aim of this study was to investigate the disease-associated genes in periodontitis. In the present experiments, the topological analysis of the differential co-expression network was proposed. Using the GSE16134 dataset downloaded from the European Molecular Biology Laboratory-European Bioinformatics Institute, a co-expression network was constructed after the differentially expressed genes (DEGs) were identified between the diseased (242 samples) and healthy (69 samples) gingival tissues from periodontitis patients. The topological properties of the modules obtained from the network as well as an analysis of transcription factors (TFs) were used to determine the disease-associated genes. The gene ontology and pathway enrichment analysis was performed to investigate the underlying mechanisms of these disease related genes. A total of 524 DEGs, including 19 TFs were identified and a co-expression network with 2569 edges was obtained. Among the 7 modules gained in the network, the TFs (ZNF215, ZEN273, NFAT5, TRPS1, MEF2C and FLI1) were considered to be important in periodontitis. The functional and pathway enrichment analysis revealed that the DEGs were highly involved in the immune system. The co-expression network analysis and TFs identified in periodontitis may provide opportunities for biomarker development and novel insights into the therapeutics of periodontitis.