Vulnerability Analysis Method Based on Network and Copula Entropy.

With the deepening of the diversification and openness of financial systems, financial vulnerability, as an endogenous attribute of financial systems, becomes an important measurement of financial security. Based on a network analysis, we introduce a network curvature indicator improved by Copula entropy as an innovative metric of financial vulnerability. Compared with the previous network curvature analysis method, the CE-based curvature proposed in this paper can measure market vulnerability and systematic risk with significant advantages.

Plasma-derived exosomes contributes to endothelial-to-mesenchymal transition in Moyamoya disease.

Background: Moyamoya disease (MMD) is a cerebrovascular disease with a high disability rate; however, its pathogenesis remains unknown. Endothelial-mesenchymal transition (EndMT) is the pathological basis of many vascular diseases; however, the key role of EndMT in MMD has not yet been reported. Method: We collected vascular tissues from three control samples and six patients with MMD to detect the expression of EndMT-related genes. To elucidate the mechanism of EndMT in MMD, we performed in vitro cell experiments. Plasma-derived exosomes (PDEs) can transmit information between cells and tissues and are of considerable importance in several disease studies. PDEs were used to stimulate EndMT phenotype in cerebrovascular endothelial cells. Results: Multiplex fluorescent immunohistochemistry staining confirmed that CD31, VE-cadherin and E-cadherin down-regulated, whereas α-SMA and vimentin were significantly up-regulated in moyamoya vascular endothelial cells than in control samples. PDEs from MMD patients significantly promoted cell proliferation and migration, resulting in slender cells. PDEs induce EndMT-related phenotype changes in cerebral vascular endothelial cells, including decreased endothelial cell marker expression and increased mesenchymal cell marker expression. We demonstrated that EndMT phenotypic alterations are mediated, in part, by microRNA(miRNAs). Conclusion: This study was the first to propose that EndMT may exist in the vessels of patients with MMD. PDEs induce the EndMT phenotype to promote the development of MMD. This study aimed to provide a new theoretical basis for elucidating the pathogenesis of MMD.

Function of Long Noncoding RNAs in Glioma Progression and Treatment Based on the Wnt/ß-Catenin and PI3K/AKT Signaling Pathways.

Gliomas are a deadly primary malignant tumor of the central nervous system, with glioblastoma (GBM) representing the most aggressive type. The clinical prognosis of GBM patients remains bleak despite the availability of multiple options for therapy, which has needed us to explore new therapeutic methods to face the rapid progression, short survival, and therapy resistance of glioblastomas. As the Human Genome Project advances, long noncoding RNAs (lncRNAs) have attracted the attention of researchers and clinicians in cancer research. Numerous studies have found aberrant expression of signaling pathways in glioma cells. For example, lncRNAs not only play an integral role in the drug resistance process by regulating the Wnt/ß-catenin or PI3K/Akt signaling but are also involved in a variety of malignant biological behaviors such as glioma proliferation, migration, invasion, and tumor apoptosis. Therefore, the present review systematically assesses the existing research evidence on the malignant progression and drug resistance of glioma, focusing on the critical role and potential function of lncRNAs in the Wnt/ß-catenin and PI3K/Akt classical pathways to promote and encourage further research in this field.

The relationship between hemoglobin and triglycerides in moyamoya disease: A cross-sectional study.

Hemoglobin (Hb) and lipid metabolism are critical in the pathophysiology of moyamoya disease (MMD), and Hb and triglycerides (TGs) both play roles in the development of cerebrovascular illness. However, there is little evidence of a link between Hb and TGs in patients with MMD. This study aimed to determine the association between Hb and TGs in patients who had recently been diagnosed with MMD. From March 2013 to December 2018, 337 patients clinically diagnosed with MMD were admitted to our hospital. Among these, 235 were selected for analysis in this retrospective, cross-sectional study. Each patient's clinical features were documented. For analysis, we used univariate analysis, smoothed-curve fitting, and multivariable, piecewise linear regression. Overall, the mean±standard deviation patient age was 48.14 ± 11.24 years, 44.68% were men, and the mean Hb concentration was 135.72 ± 18.99 g/L. After controlling for relevant confounders, smoothed-curve fitting revealed a nonlinear association between the Hb and TG concentrations (P = 0.0448). When the Hb concentration was below 141 g/L, multivariate piecewise linear regression analysis revealed a significant association between the Hb and TG concentrations [ß: 0.01, 95% confidence interval (CI): 0.00, 0.01; P = 0.0182], although the association disappeared above this threshold (ß:-0.00, 95% CI:-0.01, 0.01; P = 0.4429). In individuals newly diagnosed with MMD, there is a significant correlation between Hb and TGs, which may be connected to MMD pathogenesis.

Corilagin induces apoptosis and inhibits autophagy of HL­60 cells by regulating miR­451/HMGB1 axis.

Corilagin is the primary active component of the Euphorbia phyllanthus plant and has significant anti­cancer properties. However, the biological effects and mechanisms of corilagin on acute myeloid leukemia (AML) have not been clarified. The Cell Counting Kit­8 and Carboxyfluorescein Diacetate Succinimidyl Ester assay results showed that corilagin significantly inhibited proliferation of the AML cell line HL­60 in a time­ and dose­dependent manner. Western blotting and flow cytometry analysis were performed to determine the levels of apoptosis in HL­60 cells. The protein levels of cleaved caspase­3 and Bak were upregulated, while Bcl­xl was downregulated in cells treated with corilagin. The percentage of early­ and late­stage apoptotic cells increased following corilagin treatment in a dose­dependent manner, indicating that the intrinsic mitochondrial apoptosis pathway was activated by corilagin. Simultaneously, western blotting and immunofluorescence results revealed that autophagy was suppressed; this was accompanied by a decrease in light chain 3­II (LC3­II) conversion and autophagosomes. MicroRNA (miRNA/miR) profile analysis showed that corilagin elevated the expression of the tumor suppressor miR­451, while the mRNA and protein levels of high mobility group protein B1 (HMGB1), the target of miR­451, decreased following exposure to corilagin. Knockdown of miR­451 decreased the downregulation of HMGB1 caused by corilagin, indicating negative regulation of HMGB1 by miR­451 during corilagin treatment. Furthermore, knockdown of miR­451 also attenuated corilagin­induced proliferation inhibition of HL­60 cells, implying that miR­451 was essential for the proliferation inhibitory effect of corilagin. In conclusion, these results indicated that corilagin induced apoptosis and inhibited autophagy in HL­60 cells by regulating the miR­451/HMGB1 axis, and corilagin may be a novel therapeutic drug for the treatment of AML.

Platelet-to-Lymphocyte Ratio and Neutrophil-to-Lymphocyte Ratio in Patients With Newly Diagnosed Moyamoya Disease: A Cross-Sectional Study.

Inflammation has been proven to be one of the key factors in the pathogenesis of moyamoya disease (MMD). Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) are cheap and reliable biomarkers of inflammation. Nevertheless, evidence regarding the relationship among PLR and NLR in patients with MMD is limited. The focus of this subject was to explore the relationship between PLR and NLR in patients with newly diagnosed MMD. Patients and methods: A cross-sectional study was performed including 261 patients with diagnosed MMD for the first time who were enrolled from our hospital, from 24 March 2013 to 24 December 2018. The clinical characteristics were collected for each patient. Univariate analysis, smooth curve fitting and multivariate piecewise linear regression were showed. Results: The mean levels or median values (interquartile range) of PLR and NLR were 146.979 ± 51.203 and 2.241 (1.589-2.984), respectively. A significant positive correlation between PLR and NLR levels (P < 0.001) was showed by the univariate analysis. Furthermore, a non-linear relationship was detected between PLR and NLR by smooth curve fitting after adjusting for potential confounders. A multivariate piecewise linear regression model revealed a significant positive correlation between PLR and NLR when the PLR level was lower than 219.82 (ß 0.012, 95% CI 0.005, 0.019; P = 0.001). PLR was also significantly positively associated with NLR when PLR concentrations were >219.82 (ß 0.098, 95% CI 0.069, 0.128; P < 0.001). Conclusion: There seemed to be a positive association between PLR and NLR in patients with MMD. This may help to further explain the role of inflammation in the occurrence and progress of MMD.

Corilagin induces apoptosis and autophagy in NRF2­addicted U251 glioma cell line.

Corilagin, extracted from the Euphorbiaceae and Phyllanthus plants, inhibits the growth of a number of types of tumors. Compared with temozolomide, the traditional chemotherapy drug, corilagin has demonstrated stronger antitumor activity. However, the pharmaceutical mechanism of corilagin in glioma remains unclear. Nuclear factor erythroid 2 like 2 (NFE2L2 or NRF2) is positively associated with several types of tumor including glioma. In the present study, NRF2 expression was higher in glioma tissues compared with non­glioma specimens. Therefore, it was hypothesized that corilagin targets NRF2 regulation of U251 cell apoptosis. The present study used Hoechst 33258 staining to demonstrate that corilagin induced glioma cell apoptosis and observed that the expression of the apoptosis­related gene Bcl­2 was reduced. In addition, corilagin induced autophagy and promoted the conversion of light chain 3 (LC3) protein from LC3Ⅰ to LC3II. NRF2 expression was downregulated by corilagin stimulation. Furthermore, the gene expression pattern following knockdown of NRF2 in U251 cells using siRNA was consistent with corilagin stimulation. Therefore, it was preliminarily concluded that corilagin induces apoptosis and autophagy by reducing NRF2 expression.

Corilagin induces human glioblastoma U251 cell apoptosis by impeding activity of (immuno)proteasome.

Glioma is a type of common primary intracranial tumor, which is difficult to treat. It has been confirmed by research that corilagin (the primary active constituent of the matsumura leafflower herb) has significant antitumor effect. In particular, our previous research demonstrated that corilagin effectively promotes apoptosis of glioma U251 cells and has a synergistic effect when used with temozolomide. However, the mechanism by which corilagin causes apoptosis in U251 cells has yet to be investigated. Proteasomes are catalytic centers of the ubiquitin­proteasome system, which is the major protein degradation pathway in eukaryotic cells; they are primarily responsible for the degradation of signal molecules, tumor suppressors, cyclins and apoptosis inhibitors and serve an important role in tumor cell proliferation and apoptosis. The present study investigated the pro­apoptotic effect of corilagin on glioma U251 cells and confirmed that decreased proteasome activity and expression levels serve an important role in corilagin­induced U251 cell apoptosis.

Amino Acid-Mediated Metabolism: A New Power to Influence Properties of Stem Cells.

The self-renewal and differentiation potentials of stem cells are dependent on amino acid (AA) metabolism. We review the literature on the metabolic preference of both cancer and noncancer stem cells. The balance in AA metabolism is responsible for maintaining the functionality of noncancer stem cells, and altering the levels of AAs can influence the malignant biological behavior of cancer stem cells. AAs are considered nutrients participating in metabolism and playing a critical role in maintaining the activity of normal stem cells and the effect of therapy of cancer stem cells. Targeting AA metabolism helps inhibit the stemness of cancer stem cells and remodels the function of normal stem cells. This review summarizes the metabolic characteristics and regulation pathways of AA in different stem cells, not only from the nutritional perspective but also from the genomic perspective that have been reported in the recent five years. In addition, we briefly survey new therapeutic modalities that may help eradicate cancer stem cells by exploiting nutrient deprivation. Understanding AA uptake characteristics helps researchers define the preference for AA in different stem cells and enables clinicians make timely interventions to specifically target the cell behavior.

SPDEF is overexpressed in gastric cancer and triggers cell proliferation by forming a positive regulation loop with FoxM1.

The SAM-pointed domain-containing ETS transcription factor (SPDEF) is an epithelial-specific transcription factor of the E26 transformation-specific (ETS) family, which binds the target gene through the high-affinity sequence of GGAT. It is suggested that SPDEF targets the promoter activity of Forkhead Box M1 (FoxM1), which has been proven to be highly expressed in gastric cancer. We found that SPDEF was overexpressed both at the messenger RNA (mRNA) and at the protein level in human gastric cancer species. The gastric cancer cells transfected with the SPDEF expression plasmid or SPDEF small interfering RNA (siRNA) led to observations on the clone genetics assay that indicated the promotion or the inhibition of gastric cancer cell proliferation, respectively. Both mRNA and protein levels of FoxM1 were regulated by SPDEF in gastric cancer cells and FoxM1 was also overexpressed in the corresponding human gastric cancer species. The overexpression and inhibition of FoxM1 could upregulate and downregulate the mRNA and protein levels of SPDEF expression, respectively. The recovery experiments verified that the overexpression of FoxM1 could at least partially revert both the expression of SPDEF and the proliferation of the cell lines even with the siRNA inhibition of SPDEF. The result of the dual luciferase activity assay showed that SPDEF bound to the promoter of FoxM1 and activated it. FoxM1 might also bind to the promoter of SPDEF to affect its expression. The results were checked in vivo. In conclusion, SPDEF is overexpressed in gastric cancer, which can form a positive regulation loop with FoxM1 to promote gastric carcinogenesis.

MiR-320a inhibits gastric carcinoma by targeting activity in the FoxM1-P27KIP1 axis.

MicroRNAs (miRNAs) regulate tumorigenesis by inhibiting gene expression. In this study, we showed that miR-320a expression is decreased in human gastric cancer tissues and correlates inversely with expression of FoxM1, a key cell cycle regulator involved in gastric carcinoma. By contrast, the expression of P27KIP1, a downstream effector of FoxM1, correlates positively with miR-320a levels. Luciferase assays indicate that miR-320a suppresses FoxM1 expression, and in vitro recovery tests using FoxM1 siRNA indicate miR-320a inhibits gastric cancer cell proliferation by suppressing activity in the FoxM1-P27KIP1 axis. In vivo, nude mice injected with BGC-823 gastric cancer cells expressing a miR-320a inhibitor exhibit faster tumor growth than mice injected with control cells. Analysis of FoxM1 and P27KIP1 expression in tumor tissues indicates that miR-320a suppression increases the tumor growth by enhancing FoxM1-P27KIP1 signaling. These results thus reveal the crucial role played by miR-320a in limiting gastric carcinoma by directly targeting FoxM1- P27KIP1 axis.

Sequence conversion by single strand oligonucleotide donors via non-homologous end joining in mammalian cells.

Double strand breaks (DSBs) can be repaired by homology independent nonhomologous end joining (NHEJ) pathways involving proteins such as Ku70/80, DNAPKcs, Xrcc4/Ligase 4, and the Mre11/Rad50/Nbs1 (MRN) complex. DSBs can also be repaired by homology-dependent pathways (HDR), in which the MRN and CtIP nucleases produce single strand ends that engage homologous sequences either by strand invasion or strand annealing. The entry of ends into HDR pathways underlies protocols for genomic manipulation that combine site-specific DSBs with appropriate informational donors. Most strategies utilize long duplex donors that participate by strand invasion. Work in yeast indicates that single strand oligonucleotide (SSO) donors are also active, over considerable distance, via a single strand annealing pathway. We examined the activity of SSO donors in mammalian cells at DSBs induced either by a restriction nuclease or by a targeted interstrand cross-link. SSO donors were effective immediately adjacent to the break, but activity declined sharply beyond approximately 100 nucleotides. Overexpression of the resection nuclease CtIP increased the frequency of SSO-mediated sequence modulation distal to the break site, but had no effect on the activity of an SSO donor adjacent to the break. Genetic and in vivo competition experiments showed that sequence conversion by SSOs in the immediate vicinity of the break was not by strand invasion or strand annealing pathways. Instead these donors competed for ends that would have otherwise entered NHEJ pathways.

Targeted gene knock in and sequence modulation mediated by a psoralen-linked triplex-forming oligonucleotide.

Information from exogenous donor DNA can be introduced into the genome via homology-directed repair (HDR) pathways. These pathways are stimulated by double strand breaks and by DNA damage such as interstrand cross-links. We have employed triple helix-forming oligonucleotides linked to psoralen (pso-TFO) to introduce a DNA interstrand cross-link at a specific site in the genome of living mammalian cells. Co-introduction of duplex DNA with target region homology resulted in precise knock in of the donor at frequencies 2-3 orders of magnitude greater than with donor alone. Knock-in was eliminated in cells deficient in ERCC1-XPF, which is involved in recombinational pathways as well as cross-link repair. Separately, single strand oligonucleotide donors (SSO) were co-introduced with the pso-TFO. These were 10-fold more active than the duplex knock-in donor. SSO efficacy was further elevated in cells deficient in ERCC1-XPF, in contrast to the duplex donor. Resected single strand ends have been implicated as critical intermediates in sequence modulation by SSO, as well as duplex donor knock in. We asked whether there would be a competition between the donor species for these ends if both were present with the pso-TFO. The frequency of duplex donor knock in was unaffected by a 100-fold molar excess of the SSO. The same result was obtained when the homing endonuclease I-SceI was used to initiate HDR at the target site. We conclude that the entry of double strand breaks into distinct HDR pathways is controlled by factors other than the nucleic acid partners in those pathways.

Extensive sugar modification improves triple helix forming oligonucleotide activity in vitro but reduces activity in vivo.

We are developing triple helix forming oligonucleotides (TFOs) for gene targeting. Previously, we synthesized bioactive TFOs containing 2'-O-methylribose (2'-OMe) and 2'-O-aminoethylribose (2'-AE) residues. Active TFOs contained four contiguous 2'-AE residues and formed triplexes with high thermal stability and rapid association kinetics. In an effort to further improve bioactivity, we synthesized three series of TFOs containing the 2'-AE patch and additional ribose modifications distributed throughout the remainder of the oligonucleotide. These were either additional 2'-AE residues, the conformationally locked BNA/LNA ribose with a 2'-O,4'-C-methylene bridge, or the 2'-O,4'-C-ethylene analogue (ENA). The additionally modified TFOs formed triplexes with greater thermal stability than the reference TFO, and some had improved association kinetics. However, the most active TFOs in the biochemical and biophysical assays were the least active in the bioassay. We measured the thermal stability of triplexes formed by the TFOs in each series on duplex targets containing a change in sequence at a single position. The Tm value of the variant sequence triplexes increased as the number of all additional modifications increased. A simple explanation for the failure of the improved TFOs in the bioassay was that the increased affinity for nonspecific targets lowered the effective nuclear concentration. Enhancement of TFO bioactivity will require chemical modifications that improve interaction with the specific targets while retaining selectivity against mismatched sequences.

Ultrasound-accelerated tissue fixation/processing achieves superior morphology and macromolecule integrity with storage stability.

We demonstrate that high-frequency and high-intensity ultrasound (US) can be applied to both tissue fixation and tissue processing to complete the conventional overnight formalin-fixation and paraffin-embedding (FFPE) procedures within 1 hr. US-facilitated FFPE retains superior tissue morphology and long-term room temperature storage stability than conventional FFPE. There is less alteration of protein antigenicity after US-FFPE preservation so that rapid immunohistochemical reactions occur with higher sensitivity and intensity, reducing the need for antigen retrieval pretreatment. US-FFPE tissues present storage stability so that room temperature storage up to 7 years does not significantly affect tissue morphology, protein antigenic properties, RNA distribution, localization, and quantitation. In addition, during fixation, tissue displays physical changes that can be monitored and reflected as changes in transmission US signals. As far as we know, this is the first effort to monitor tissue physical changes during fixation. Further study of this phenomenon may provide a method to control and to monitor the level of fixation for quality controls. The mechanism of less alteration of protein antigenicity by US-FFPE was discussed.

Triplex targeted genomic crosslinks enter separable deletion and base substitution pathways.

We have synthesized triple helix forming oligonucleotides (TFOs) that target a psoralen (pso) interstrand crosslink to a specific chromosomal site in mammalian cells. Mutagenesis of the targeted crosslinks results in base substitutions and deletions. Identification of the gene products involved in mutation formation is important for developing practical applications of pso-TFOs, and may be informative about the metabolism of other interstrand crosslinks. We have studied mutagenesis of a pso-TFO genomic crosslink in repair proficient and deficient cells. Deficiencies in non homologous end joining and mismatch repair do not influence mutation patterns. In contrast, the frequency of base substitutions is dependent on the activity of ERCC1/XPF and polymerase zeta, but independent of other nucleotide excision repair (NER) or transcription coupled repair (TCR) genes. In NER/TCR deficient cells the frequency of deletions rises, indicating that in wild-type cells NER/TCR functions divert pso-TFO crosslinks from processes that result in deletions. We conclude that targeted pso-TFO crosslinks can enter genetically distinct mutational routes that resolve to base substitutions or deletions.

A nondestructive molecule extraction method allowing morphological and molecular analyses using a single tissue section.

In clinical practice, molecular analysis of tumor specimens is often restricted by available technology for sample preparation. Virtually all current methods require homogenization of tissues for molecule extraction. We have developed a simple, rapid, nondestructive molecule extraction (NDME) method to extract proteins and nucleic acids directly from a single fixed or frozen tissue section without destroying the tissue morphology. The NDME method is based upon exposure of micron-thick tissue section to extraction buffer with the help of heating and/or intact physical forces (ultrasound and microwave) to facilitate release of macromolecules into the buffer. The extracted proteins and nucleic acids can be used directly without further purification for downstream SDS-PAGE analysis, immunoblotting, protein array, mass spectra protein profiling, PCR, and RT-PCR reactions. Most importantly, the NDME procedure also serves as an antigen retrieval treatment, so that after NDME, the same tissue section can be used for histopathological analyses, such as H&E staining, immunohistochemistry, and in situ hybridization. Thus, the NDME method allows, for the first time, both histological diagnosis and molecular analysis on a single tissue section, whether it is from frozen or fixed tissue specimens.