MDM2 provides TOP2 poison resistance by promoting proteolysis of TOP2βcc in a p53-independent manner

DNA topoisomerase II (TOP2) is an enzyme that performs a critical function in manipulating DNA topology during replication, transcription, and chromosomal compaction by forming a vital intermediate known as the TOP2-DNA cleavage complex (TOP2cc). Although the TOP2cc is often transient, stabilization can be achieved by TOP2 poisons, a family of anti-cancer chemotherapeutic agents targeting TOP2, such as etoposide (VP-16), and then induce double-strand breaks (DSBs) in cellular DNA. TOP2cc first needs to be proteolyzed before it can be processed by TDP2 for the removal of these protein adducts and to produce clean DNA ends necessary for proper repair. However, the mechanism by which TOP2βcc is proteolyzed has not been thoroughly studied. In this study, we report that after exposure to VP-16, MDM2, a RING-type E3 ubiquitin ligase, attaches to TOP2β and initiates polyubiquitination and proteasomal degradation. Mechanistically, during exposure to VP-16, TOP2β binds to DNA to form TOP2βcc, which promotes MDM2 binding and subsequent TOP2β ubiquitination and degradation, and results in a decrease in TOP2βcc levels. Biologically, MDM2 inactivation abrogates TOP2β degradation, stabilizes TOP2βcc, and subsequently increases the number of TOP2β-concealed DSBs, resulting in the rapid death of cancer cells via the apoptotic process. Furthermore, we demonstrate the combination activity of VP-16 and RG7112, an MDM2 inhibitor, in the xenograft tumor model and in situ lung cancer mouse model. Taken together, the results of our research reveal an underlying mechanism by which MDM2 promotes cancer cell survival in the presence of TOP2 poisons by activating proteolysis of TOP2βcc in a p53-independent manner, and provides a rationale for the combination of MDM2 inhibitors with TOP2 poisons for cancer therapy.

Construction of RNA Methylation Modification-immune-related lncRNA Molecular Subtypes and Prognostic Scoring System in Lung Adenocarcinoma

BACKGROUND

RNA methylation modification is not only intimately interrelated with cancer development and progression but also actively influences immune cell infiltration in the tumor microenvironment (TME). RNA methylation modification genes influence the therapeutic progression of lung adenocarcinoma (LUAD), and mining RNA methylation modification prognosis-related markers in LUAD is crucial for its precise prognosis.

METHODS

RNA-Seq data and Gene sets were collected from online databases or published literature. Genomic variation analysis was conducted by the Maftools package. RNA methylation-immune-related lncRNAs were obtained by Pearson correlation analysis. Then, Consistent clustering analysis was performed to obtain RNA methylation modification- immune molecular subtypes (RMM-I Molecular subtypes) in LUAD based on selected lncRNAs. COX and random survival forest analysis were carried out to construct the RMM-I Score. The receiver operating characteristic (ROC) curve and Kaplan Meier survival analysis were used to assess survival differences. Tumor immune microenvironment was assessed through related gene signatures and CIBERSORT algorithm. In addition, drug sensitivity analysis was executed by the pRRophetic package.

RESULTS

Four RNA methylation modified-immune molecular subtypes (RMM-I1, RMM- I2, RMM-I3, RMM-I4) were presented in LUAD. Patients in RMM-I4 exhibited excellent survival advantages and immune activity. HAVCR2, CD274, and CTLA-4 expression were activated in RMM-I4, which might be heat tumors and a potential beneficial group for immunotherapy. OGFRP1, LINC01116, DLGAP1-AS2, CRNDE, LINC01137, MIR210HG, and CYP1B1-AS1 comprised the RMM-I Score. The RMM-I Score exhibited excellent accuracy in the prognostic assessment of LUAD, as patients with a low RMM- I Score exhibited remarkable survival advantage. Patients with a low RMM-I score might be more sensitive to treatment with Docetaxel, Vinorelbine, Paclitaxel, Cisplatin, and immunotherapy.

CONCLUSION

The RMM-I molecular subtype constituted the novel molecular characteristic subtype of LUAD, which complemented the existing pathological typing. More refined and accurate molecular subtypes provide help to reveal the mechanism of LUAD development. In addition, the RMM-I score offers a reliable tool for accurate prognosis of LUAD.

Identification of novel gene signature for lung adenocarcinoma by machine learning to predict immunotherapy and prognosis

Background

Lung adenocarcinoma (LUAD) as a frequent type of lung cancer has a 5-year overall survival rate of lower than 20% among patients with advanced lung cancer. This study aims to construct a risk model to guide immunotherapy in LUAD patients effectively.

Materials and methods

LUAD Bulk RNA-seq data for the construction of a model, single-cell RNA sequencing (scRNA-seq) data (GSE203360) for cell cluster analysis, and microarray data (GSE31210) for validation were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. We used the Seurat R package to filter and process scRNA-seq data. Sample clustering was performed in the ConsensusClusterPlus R package. Differentially expressed genes (DEGs) between two groups were mined by the Limma R package. MCP-counter, CIBERSORT, ssGSEA, and ESTIMATE were employed to evaluate immune characteristics. Stepwise multivariate analysis, Univariate Cox analysis, and Lasso regression analysis were conducted to identify key prognostic genes and were used to construct the risk model. Key prognostic gene expressions were explored by RT-qPCR and Western blot assay.

Results

A total of 27 immune cell marker genes associated with prognosis were identified for subtyping LUAD samples into clusters C3, C2, and C1. C1 had the longest overall survival and highest immune infiltration among them, followed by C2 and C3. Oncogenic pathways such as VEGF, EFGR, and MAPK were more activated in C3 compared to the other two clusters. Based on the DEGs among clusters, we confirmed seven key prognostic genes including CPA3, S100P, PTTG1, LOXL2, MELTF, PKP2, and TMPRSS11E. Two risk groups defined by the seven-gene risk model presented distinct responses to immunotherapy and chemotherapy, immune infiltration, and prognosis. The mRNA and protein level of CPA3 was decreased, while the remaining six gene levels were increased in clinical tumor tissues.

Conclusion

Immune cell markers are effective in clustering LUAD samples into different subtypes, and they play important roles in regulating the immune microenvironment and cancer development. In addition, the seven-gene risk model may serve as a guide for assisting in personalized treatment in LUAD patients.

ATM inhibitor KU60019 synergistically sensitizes lung cancer cells to topoisomerase II poisons by multiple mechanisms

Type II topoisomerases (TOP2) poisons represent one class of the most successful and widely prescribed chemotherapeutics, which is frontline therapy for a myriad of systemic cancers and solid tumors, including lymphomas, leukemias, and lung cancer. Despite this, treatment with this class of drugs induces unwanted side effects (including cardiovascular morbidity and secondary malignancies). Additionally, the emergence of drug resistance also greatly compromises the clinical use of these drugs. To enhance therapeutic efficiency while lowering unwanted side effects, new insights into effective combination therapy are required. In this study we found that KU60019, a novel, and highly specific ATM kinase inhibitor interferes with the association of ATM with TOP2β and stabilizes TOP2β-DNA cleavage complex, thereby impairing the repair of TOP2 poison-induced DSBs and contributes to genome stability, leading to accelerated cell death. In H1299 as well as in A549 lung cancer cell lines, biologically, KU60019 combined with VP-16 (one of the TOP2 poisons) synergistically suppressed the growth of cells and survival and triggered a much higher apoptosis rate. In summary, we provide a proof-of-concept strategy that ATM inhibitors combined with TOP2 poison would synergistically suppresses lung cancer cell survival as well as reduce DNA damage responses, thus may lowering the possibility of cardiotoxicity and secondary malignancy linked to therapy.

Effect of Somatosensory Interaction Transcutaneous Electrical Acupoint Stimulation on Cancer-related Fatigue and Immunity: A Randomized Controlled Trial

BACKGROUND

This study was intended to evaluate the clinical effect of somatosensory interaction transcutaneous electrical acupoint stimulation (SI-TEAS) on cancer-related fatigue (CRF) and its safety.

METHODS

The study protocol had been registered in China Clinical Trial Registration Center with registration number: ChiCTR2100045655. CRF patients were equally divided into SI-TEAS Group, Acupressure Group and Sham Acupressure Group to receive SI-TEAS, acupressure and sham acupressure treatments 5 times a week. The fatigue levels of patients in the 3 groups were measured by the Piper Fatigue Scale during the baseline period and after 4 and 8 weeks (of treatment). The cell immunity of these patients was determined by detecting the T-lymphocyte subsets and NK cells.

RESULT

Of the 300 participants, 279 have gone through the independent rehabilitation intervention study, including 94 in the SI-TEAS Group, 92 in the Acupressure Group, and 93 in the Sham Acupressure Group. Intergroup comparisons of fatigue degree and cell immunity, namely SI-TEAS Group versus Acupressure Group, Acupressure Group versus Sham Acupressure Group, and SI-TEAS Group versus Sham Acupressure Group, showed that group changes observed during the baseline period and different time points after Week 4 and 8 were statistically different (P<0.05). The SI-TEAS Group had the sharpest decreases in the behavioral, sensory, emotional and cognitive dimensions of fatigue, and the total score, followed by the Acupressure Group, while the Sham Acupressure Group did not show significant changes; the SI-TEAS Group experienced the sharpest increases in the absolute counts of CD3+ T cells, CD4+ T cells, CD8+ T cells, CD4+/CD8+ T cells, and NK cells, followed by the Acupressure Group, while the Sham Acupressure Group did not show significant changes.

CONCLUSION

SI-TEAS could significantly relieve the fatigue of CRF patients and improve their cell immunity, which maybe a useful and effective option for reducing CRF in clinical practice.

Spatiotemporal characteristics and influencing factors of urban resilience efficiency in the Yangtze River Economic Belt, China

Urban resilience efficiency is an important indicator to explore the relationship between resource consumption and urban resilience, shedding new light on the study of urban sustainable development. Based on the panel data of 2008, 2012, and 2017, this paper makes a spatiotemporal assessment on the urban resilience efficiency of 126 cities in the Yangtze River Economic Belt (YREB) in China by applying an entropy weight-TOPSIS method and a slack-based measure (SBM) model. Combined with the analysis of a geographically weighted regression model (GWR), the influencing factors on resilience efficiency are also investigated. The results show that both the resource consumption index (RC, inputs) and the urban resilience index (UR, outputs) presented a steady upward trend, and their spatial distribution characteristics were similar, showing a gradual decrease from the eastern coastal cities to the central and western inland cities. Derived from inputs and outputs, the mean values of resilience efficiency index (RE) in three periods were 0.3149, 0.2906, and 0.1625, respectively, revealing that there had been a noticeable decline. Spatially, its spatial distribution has evolved from a relatively balanced pattern to an unbalanced one, showing a gradual decrease from west to east. The results of the GWR model analysis indicate that the total electricity consumption and area of construction land had a considerable correlation with the overall urban resilience of the YREB. Furthermore, total quantity of water supply and science and technology (S&T) expenditure continued to be the main driving factors on urban resilience of the upstream cities. The midstream regions mainly depended on the scale of construction land, and the influencing factors are relatively single. The influencing factors in the downstream areas have changed from dominance of resources and capital factors to the single dominance of resource factors, and total electricity consumption had a strong explanatory power. Based on these findings, we had put forward the overall and local regional policy implications.

Induction of p27 contributes to inhibitory effect of isorhapontigenin (ISO) on malignant transformation of human urothelial cells

Bladder cancer (BC) is the most expensive cancer to manage on a per-patient basis, costing about $4 billion in total healthcare expenditure per annum in America alone. Therefore, identifying a natural compound for prevention of BC is of tremendous importance for managing this disease. Previous studies have identified isorhapontigenin (ISO) as having an 85% preventive effect against invasive BC formation induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). The results showed here that ISO treatment inhibited EGF-induced cell transformation of human urothelial cells through induction of tumor suppressor p27 transcription secondary to activation of an E2F1-dependentpathway.ISOtreatmentrenderedcellsresistanttoEGF-induced anchorage-independent growth concurrent with p27 protein induction in both UROtsa and SV-HUC-1 cells. ISO inhibition of EGF-induced cell transformation could be completely reversed by knockdown of p27, indicating that this protein was essential for the noted ISO inhibitory action. Mechanistic studies revealed that ISO treatment resulted in increased expression of E2F1, which in turn bound to its binding site in p27 promoter and initiated p27 transcription. The E2F1 induction was due to the elevation of its translation caused by ISO-induced miR-205 downregulation. Consistently, miR-205 was found to be overexpressed in human BCs, and ectopic expression of miR-205 mitigated ISO inhibitory effects against EGF-induced outcomes. Collectively, the results here demonstrate that ISO exhibits its preventive effect on EGF-induced human urothelial cell transformation by induction of p27 through a miR-205/E2F1 axis. This is distinct from what has been described for the therapeutic effects of ISO on human BC cells.

Territorial Resilience of Metropolitan Regions: A Conceptual Framework, Recognition Methodologies and Planning Response-A Case Study of Wuhan Metropolitan Region

As the key link and spatial form of urbanization in China, metropolitan region development has become a strategic frontier issue in the field of regional planning and territorial resilience. This paper defines the essence of territorial resilience of metropolitan regions, analyses the capacity of the system and its elements, and builds a regional planning framework. An evaluation indicator system is constructed to evaluate the territorial resilience level and identify the limiting factors in the Wuhan metropolitan region by utilizing the grey correlation model and the obstacle degree model. The results show that the resilience of Wuhan metropolitan region forms an overall pattern of one core area and four sub-regions in the east, west, north and south. According to the different limiting factors of resilience, cities can be divided into three types: cities limited by both policy and spatial resource factors, cities with lagging socioeconomic factors, and cities with insufficient innovation factors. This paper proposes planning response strategies to enhance resilience from two spatial levels. At the regional level this can be done by building a gradually balanced urban system, establishing three areas based on the degree of resilience factor agglomeration, while at the urban level it can be accomplished by maintaining ecological security, promoting economic agglomeration development and constructing innovation networks.

Regulation of topoisomerase II stability and activity by ubiquitination and SUMOylation: clinical implications for cancer chemotherapy

DNA topoisomerases II (TOP2) are peculiar enzymes (TOP2α and TOP2β) that modulate the conformation of DNA by momentarily breaking double-stranded DNA to allow another strand to pass through, and then rejoins the DNA phosphodiester backbone. TOP2α and TOP2β play vital roles in nearly all events involving DNA metabolism, including DNA transcription, replication, repair, and chromatin remodeling. Beyond these vital functions, TOP2 enzymes are therapeutic targets for various anticancer drugs, termed TOP2 poisons, such as teniposide, etoposide, and doxorubicin. These drugs exert their antitumor activity by inhibiting the activity of TOP2-DNA cleavage complexes (TOP2ccs) containing DNA double-strand breaks (DSBs), subsequently leading to the degradation of TOP2 by the 26S proteasome, thereby exposing the DSBs and eliciting a DNA damage response. Failure of the DSBs to be appropriately repaired leads to genomic instability. Due to this mechanism, patients treated with TOP2-based drugs have a high incidence of secondary malignancies and cardiotoxicity. While the cytotoxicity associated with TOP2 poisons appears to be TOP2α-dependent, the DNA sequence rearrangements and formation of DSBs appear to be mediated primarily through TOP2β inhibition, likely due to the differential degradation patterns of TOP2α and TOP2β. Research over the past few decades has shown that under various conditions, the ubiquitin-proteasome system (UPS) and the SUMOylation pathway are primarily responsible for regulating the stability and activity of TOP2 and are therefore critical regulators of the therapeutic effect of TOP2-targeting drugs. In this review, we summarize the current progress on the regulation of TOP2α and TOP2β by ubiquitination and SUMOylation. By fully elucidating the basic biology of these essential and complex molecular mechanisms, better strategies may be developed to improve the therapeutic efficacy of TOP2 poisons and minimize the risks of therapy-related secondary malignancy.

DEPTOR inhibits lung tumorigenesis by inactivating the EGFR-mTOR signals

DEPTOR plays vital roles in the regulation of cell proliferation and survival by directly modulating the activity of mTORC1/2. However, the physiological role of DEPTOR in lung tumorigenesis, as well as its clinical significance, remains elusive. In this study, we revealed that decreased DEPTOR expression correlated with increased tumor size, poor differentiation, and worse survival in patients with lung cancer. DEPTOR depletion promoted cell proliferation, survival, migration, and invasion in human lung cancer cells. Mechanistically, DEPTOR bound to the kinase domain of EGFR via its PDZ domain to inactivate EGFR signal. Thus, DEPTOR depletion not only directly activated mTORC1/2, but also relieved the inhibition of EGFR to subsequently activate mTOR signals, leading to the induction of cell proliferation and survival. Additionally, activated EGFR-mTOR signals upregulated the expression of ZEB1 and SLUG to induce epithelial-mesenchymal transition, resulting in enhanced migration and invasion. Importantly, Deptor deletion accelerated Kras^G12D;p53^fl/fl-induced lung tumorigenesis and shortened mouse life span via the activation of EGFR-mTOR signals. Collectively, our study demonstrated that DEPTOR acts as a tumor suppressor in lung tumorigenesis, and its reduction may advance the progression of human lung cancer.

Functional characterization of the long noncoding RNA MIR22HG as a tumour suppressor in cervical cancer by targeting IGF2BP2

OBJECTIVE

Cervical cancer is the most common malignant tumour in the female reproductive tract, ranking second in the global cause of female cancer and seriously endangering women's health. However, the underlying mechanisms leading to cervical cancer are unclear. Previous studies have reported the roles and general underlying mechanisms of the long noncoding RNA MIR22HG (MIR22HG) in multiple types of tumours.

PATIENTS AND METHODS

In this study, we describe the functional role of MIR22HG as a tumour suppressor lincRNA by regulating metastasis, growth and invasion by performing a series of in vivo and in vitro experiments.

RESULTS

Our data suggested that MIR22HG dramatically promoted cervical cancer apoptosis and inhibited invasion by targeting IGF2BP2.

CONCLUSIONS

The long noncoding RNA MIR22HG targets IGF2BP2 as a tumour suppressor in cervical cancer. Our findings will be helpful for developing potential therapeutics for cervical cancer.

FBXW7 Confers Radiation Survival by Targeting p53 for Degradation

The tumor suppressor p53 plays a critical role in integrating a wide variety of stress responses. Therefore, p53 levels are precisely regulated by multiple ubiquitin ligases. In this study, we report that FBXW7, a substrate recognition component of the SKP1-CUL1-F-box (SCF) E3 ligase, interacts with and targets p53 for polyubiquitination and proteasomal degradation after exposure to ionizing radiation or etoposide. Mechanistically, DNA damage activates ATM to phosphorylate p53 on Ser33 and Ser37, which facilitates the FBXW7 binding and subsequent p53 degradation by SCF^FBXW7. Inactivation of ATM or SCF^FBXW7 by small molecular inhibitors or genetic knockdown/knockout approaches extends the p53 protein half-life upon DNA damage in an MDM2-independent manner. Biologically, FBXW7 inactivation sensitizes cancer cells to radiation or etoposide by stabilizing p53 to induce cell-cycle arrest and apoptosis. Taken together, our study elucidates a mechanism by which FBXW7 confers cancer cell survival during radiotherapy or chemotherapy via p53 targeting.

Prognostic value of neutrophil-lymphocyte ratio in critically ill patients with cancer: a propensity score matching study

BACKGROUND

Neutrophil-lymphocyte ratio (NLR) has shown a good prognostic value in many different type of malignancies. The purpose of this study was to investigate the relationship between NLR and the outcome of critically ill patients with cancer.

METHODS

We performed a single-institution, retrospective study of 1317 adult critically ill patients with cancer and determined the optimal cut-off for NLR by X-tile software. Propensity score matching (PSM) and inverse probabilities of treatment weighting (IPTW) were performed to control confounders. Cox proportional hazards model was used to evaluate the relationship between NLR and 28-day, 6-month and 1-year all-cause mortality. Kaplan-Meier method, subgroup analysis, and receiver operating characteristics (ROC) analysis were applied to assess the prognostic value of NLR.

RESULTS

The cut-off value for NLR was 17.6. Cox proportional hazards model demonstrated that high NLR (> 17.6) was independently associated with 28-day, 6-month and 1-year all-cause mortality with hazard ratio (HR) of 1.58 (1.29, 1.94), 1.51 (1.28, 1.77) and 1.45 (1.25, 1.69), respectively. The results were consistent with survival analyses (p < 0.001, log-rank test). The ROC analyses showed that the discrimination abilities of NLR were better than other blood-based biomarkers.

CONCLUSION

NLR is a promising prognostic indicator of survival in unselected critical ill patients with cancer.

[Clinical application effects of portable visual retractor in superficial temporal fascia flap harvesting]

Objective: To explore the clinical application effects of portable visual retractor in superficial temporal fascia flap harvesting. Methods: From January 2010 to June 2019, 27 patients meeting the inclusion criteria and planning to perform operation of superficial temporal fascia flap harvesting were admitted to the Department of Plastic and Reconstructive Surgery of the First Clinical Medical Center of the People's Liberation Army General Hospital. The patients were divided into traditional surgical method group [6 males and 3 females, aged (34±14) years], cold light source retractor group [6 males and 4 females, aged (35±16) years], and portable visual retractor group [7 males and 1 female, aged (30±14) years] according to way of superficial temporal fascia flap harvesting. The superficial temporal fascia flaps of patients in traditional surgical method group were resected by traditional way of resection, and the superficial temporal fascia flaps of patients in cold light source retractor group and portable visual retractor group were resected at assistance of cold light source retractor and portable visual retractor, respectively. Length of incision, operation time, intraoperative blood loss volume, postoperative drainage volume, and postoperative complication of patients in 3 groups were observed and recorded. Data were processed with Fisher's exact probability test, one-way analysis of variance, least significant difference test, Kruskal-Wallis H test, and Bonferroni correction. Results: The length of incision of patients in visual retractor group was (3.6±0.8) cm, significantly shorter than (12.6±1.6) cm in traditional surgical method group and (5.8±0.9) cm in cold light source retractor group (P<0.05). The incision length of patients in traditional surgical method group was significantly longer than that in cold light source retractor group (P<0.05). The operation time of patients in visual retractor group was 24.0 (23.3, 25.8) min, significantly shorter than 35.0 (30.5, 36.5) min in traditional surgical method group and 28.5 (26.8, 30.5) min in cold light source retractor group (H=16.5, 9.8, P<0.05). The operation time of patients in traditional surgical method group was significantly longer than that in cold light source retractor group (H=6.6, P<0.05). The intraoperative blood loss volume was (26±3) mL of patients in visual retractor group, significantly less than (34±4) mL in traditional surgical method group and (30±6) mL in cold light source retractor group (P<0.05). The intraoperative blood loss volume of patients in traditional surgical method group was significantly more than that in cold light source retractor group (P<0.05). The postoperative drainage volumes of patients in visual retractor group, cold light source retractor group, and traditional surgical method group were (33±4), (34±6), and (31±7) mL, respectively, and there were no significantly statistical differences in postoperative drainage volumes among patients in the three groups (F=0.3, P>0.05). There were no severe complications such as ischemia and necrosis of superficial temporal fascia flaps in patients of the three groups. One patient in cold light source retractor group had subcutaneous hematoma after operation, which was improved by removing stitches and hematoma. Conclusions: Superficial temporal fascia flap harvesting at the assistance of portable visual retractor has the advantages of clear visual field, simple operation, short operation time, small incision, and less intraoperative blood loss.

Efficient electrochemical generation of ferrate(VI) by iron coil anode imposed with square alternating current and treatment of antibiotics

Anode passivation is still a main challenge for the electrochemical generation of ferrate(VI, Fe(VI)), leading to the reduction of Fe(VI) production efficiency. In this study, cyclic voltammetry, scanning electronic microscopy, and electrochemical impedance spectroscopy were used to select better anode electrode configurations (iron wire, iron gauze, and iron coil). The results indicate that iron coil had the least degree of passivation. Different imposed current waveforms during the electrochemical generation of Fe(VI) were also investigated, and the iron coil imposed with square alternating current (AC) wave can mitigate the anode passivation, resulting in higher Fe(VI) production efficiency. The optimum conditions for the electrochemical generation of Fe(VI) were evaluated and the optimum temperature (40 ℃), current density (10 mA/cm²), AC cycle period (15 s) and electrolyte concentrations (14 M NaOH) were identified. As a result, 0.12 mol/L Fe(VI) concentration and over 50% of current efficiency can be achieved after 3 h electrolysis. The generated Fe(VI) solution was further applied to oxidize doxycycline(DOX) and sulfadiazine(SDZ) as typical antibiotics. Over 80% of DOX can be removed at a Fe(VI) to DOX molar ratio of 5:1 (pH = 4-9), whilst a higher Fe(VI) to SDZ molar ratio of 20:1 (pH = 7) was needed to obtain 75% SDZ removal.

The cross talk of two family members of β-TrCP in the regulation of cell autophagy and growth

β-transducin repeat-containing protein (β-TrCP), one of the best-characterized substrate recognition components of the SKP1-CUL1-F-box (SCF) E3 ligase, has two distinct paralogs, β-TrCP1 and β-TrCP2, expressed in mammals. Through governing the ubiquitination and degradation of numerous key regulators, β-TrCP1/2 regulates various cellular physiological and pathological processes. However, whether and how these two proteins cross talk and whether they regulate cell autophagy and proliferation in different manners is completely unknown. Herein, we report that β-TrCP1 and β-TrCP2 are the physiological substrates of SCF E3 ligase and target each other for degradation that is dependent on their β-TrCP degron sequences. Furthermore, glucose deprivation activates AMPK kinase to phosphorylate β-TrCP1 and promotes the subsequent ubiquitination and degradation of β-TrCP1 by β-TrCP2, but does not promote β-TrCP2 degradation by β-TrCP1. Finally, we found that β-TrCP2, not β-TrCP1, preferentially degrades DEPTOR and REDD1, the inhibitors of mTORC1, to activate mTORC1, leading to autophagy inhibition and cell growth. Thus, our study demonstrates that β-TrCP1 and β-TrCP2 mutually target each other for degradation and that β-TrCP2 acts as a dominant paralog in the regulation of cell autophagy and growth, which might be a promising anticancer target.

Improving the effectiveness of lifestyle interventions for gestational diabetes prevention: a meta-analysis and meta-regression

BACKGROUND

Diet and exercise during pregnancy have been used to prevent gestational diabetes mellitus (GDM) with some success.

OBJECTIVE

To examine the effectiveness of lifestyle intervention on GDM prevention and to identify key effectiveness moderators to improve the prevention strategy.

SEARCH STRATEGY

Pubmed, Scopus, Cochrane, and cross-references were searched.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating lifestyle interventions during pregnancy for GDM prevention.

DATA COLLECTION AND ANALYSIS

Two independent reviewers extracted data. A random-effects model was used to analyse the relative risk (RR) and 95% confidence interval (95% CI). Meta-regressions and subgroup analyses were used to investigate important moderators of effectiveness.

MAIN RESULTS

Forty-seven RCTs involving 15 745 participants showed that diet and exercise during pregnancy were preventive of GDM (RR 0.77, 95% CI 0.69-0.87). Four key aspects were identified to improve the preventive effect: targeting the high-risk population; an early initiation of the intervention; the correct intensity and frequency of exercise; and gestational weight gain management. Although 24 RCTs targeted women who were overweight or obese, body mass index (BMI) failed to predict the effectiveness of an intervention. Instead, interventions are most effective in high-incidence populations rather than simply in women who are overweight or obese. Furthermore, exercise of moderate intensity for 50-60 minutes twice a week could lead to an approximately 24% reduction in GDM.

CONCLUSION

The best strategy to prevent GDM is to target the high-risk population predicted by risk evaluation models and to control the gestational weight gain of women through intensified diet and exercise modifications early in their pregnancy.

TWEETABLE ABSTRACT

Four key effectiveness moderators of lifestyle interventions for GDM prevention.

AKT inhibitor MK-2206 sensitizes breast cancer cells to MLN4924, a first-in-class NEDD8-activating enzyme (NAE) inhibitor

Breast cancer is a common type of cancer among female cancer patients and the main cause of cancer-related deaths. During the last decades, targeted therapies for breast cancer have been rapidly developing. Among them, MLN4924, a first-in-class NEDD8-activating enzyme (NAE) inhibitor, has performed antitumor activity by inactivating the cullin-RING ligases and causing the accumulation of their substrates to induce apoptosis in a number of studies. In this study, we found that MLN4924 activates the AKT pathway in both HER2-positive and triple-negative breast cancer (TNBC) cell lines. Given that AKT signaling is responsible for tumor progression and drug resistance in some types of cancers, we hypothesized that the AKT inhibitor may synergistically enhance the tumor suppression capability in breast cancer by MLN4924. To demonstrate the sensitizing effect, MK-2206 was chosen as the adjuvant treatment, and cell growth, migration and apoptosis were detected. The results showed that MLN4924 treatment inhibited cell growth and migration and induced apoptosis in both SK-BR3 and MDA-MB231 breast cancer cell lines. More importantly, the combined treatment of MLN4924 and MK-2206 indeed caused stronger cytotoxicity and inhibition of migration and a much higher induction of apoptosis compared with MLN4924 treatment alone. Our study provides the proof-of-concept evidence for strategic drug combination of MLN4924 with an AKT inhibitor for maximal killing of breast cancer cells via the enhancement of apoptosis.

Long non-coding RNA EPB41L4A-AS2 inhibited non-small cell lung cancer proliferation, invasion and promoted cell apoptosis

The aim of the research was to investigate the expression of lncRNA EPB41L4A-AS2 in non-small cell lung cancer (NSCLC) and evaluate its influence on the proliferation, invasion and apoptosis of NSCLC. A total of 56 NSCLC tissues and its corresponding adjacent tissues were collected. Quantitative Reverse transcription polymerase chain reaction (qRT-PCR) was performed to evaluate the lncRNA EPB41L4A-AS2 expression level in tissues and cell lines. Proliferating cell nuclear antigen (PCNA) protein level was determined by western blot assay. CCK8 assay, EdU assay, flow cytometry (FCM) and transwell assay were performed to access cell proliferation, apoptosis and invasion. EPB41L4A-AS2 expression was significantly downregulated in cancer tissues and cells compared with the adjacent tissues and normal cells (P<0.05). After cells were transfected with pcDNA3.1-EPB41L4A-AS2, cell viability and PCNA protein level was decreased, and cells were arrested in the G0/G1 phase with higher apoptosis rate. Transwell assay showed that over-expressed EPB41L4A-AS2 could reduce cells invasion ability. Expression of low levels of EPB41L4A-AS2 is associated with poor survival in NSCLC and the over-expression of lncRNA EPB41L4A-AS2 inhibits NSCLC cell proliferation, invasion and promote cell apoptosis.

Multiregion whole-exome sequencing of matched primary and metastatic tumors revealed genomic heterogeneity and suggested polyclonal seeding in colorectal cancer metastasis

Background

Distant metastasis accounts for 90% of deaths from colorectal cancer (CRC). Genomic heterogeneity has been reported in various solid malignancies, but remains largely under-explored in metastatic CRC tumors, especially in primary to metastatic tumor evolution.

Patients and methods

We conducted high-depth whole-exome sequencing in multiple regions of matched primary and metastatic CRC tumors. Using a total of 28 tumor, normal, and lymph node tissues, we analyzed inter- and intra-individual heterogeneity, inferred the tumor subclonal architectures, and depicted the subclonal evolutionary routes from primary to metastatic tumors.

Results

CRC has significant inter-individual but relatively limited intra-individual heterogeneity. Genomic landscapes were more similar within primary, metastatic, or lymph node tumors than across these types. Metastatic tumors exhibited less intratumor heterogeneity than primary tumors, indicating that single-region sequencing may be adequate to identify important metastasis mutations to guide treatment. Remarkably, all metastatic tumors inherited multiple genetically distinct subclones from primary tumors, supporting a possible polyclonal seeding mechanism for metastasis. Analysis of one patient with the trio samples of primary, metastatic, and lymph node tumors supported a mechanism of synchronous parallel dissemination from the primary to metastatic tumors that was not mediated through lymph nodes.

Conclusions

In CRC, metastatic tumors have different but less heterogeneous genomic landscapes than primary tumors. It is possible that CRC metastasis is, at least partly, mediated through a polyclonal seeding mechanism. These findings demonstrated the rationale and feasibility for identifying and targeting primary tumor-derived metastasis-potent subclones for the prediction, prevention, and treatment of CRC metastasis.

[Relationship between hyperuricemia and prognosis in patients with heart failure of coronary heart disease after revascularization]

Objective: To explore the effect of hyperuricemia on prognosis in patients with heart failure of coronary heart disease (CHD) after revascularization. Methods: A single-center retrospective study of all subjects who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) as revascularization for CHD at Beijing Anzhen Hospital, Capital Medical University, between January 2005 and December 2014 was performed.Patients were divided into two groups by with or without hyperuricemia.The average follow-up was 1 818 d. Results: The Logistic regression analysis revealed that hyperuricemia was independent risk factors of readmission of heart failure(P=0.018, OR=1.499, 95%CI 1.071-2.098). The Cox regression analysis revealed that hyperuricemia was independent risk factor of all-cause mortality(P=0.002, RR=1.520, 95%CI 1.166-1.982), cardiovascular (CV) mortality(P=0.001, RR=1.811, 95%CI 1.279-2.566), heart failure mortality(P=0.006, RR=2.151, 95%CI 1.247-3.711). Conclusions: There is negative correlation between level of uric acid and left ventricular ejection fraction (LVEF). The patients with heart failure of coronary heart disease complicated with hyperuricemia have high risk of readmission of heart failure, all-cause mortality, CV mortality andheart failure mortality than patients with normal uric acid level. Hyperuricemia is an independent risk factor for patients with heart failure of coronary heart disease after revascularization.

Chicken egg-white extracts promote OCT4 and NANOG expression and telomeres growth in 293T cells

It will have broad applications in cell biology if one of egg cell extracts has the roles to promote cell proliferation and reprogramming. It will provide a new method for easier reprogramming somatic cells and promote cell proliferation. We found chicken egg-white extracts have roles to promote cell proliferation and reprogramming. The different ingredients were then assessed for cell proliferation activity and somatic cell reprogramming. Chicken egg-white extract ingredients that were less than 3 kDa (LT3K) promoted cell proliferation. Those ingredients that were greater than 3 kDa (GT3K) promoted the increased expression of pluripotency factors in somatic cells and promote telomeres growth in 293T cells. Chicken egg-whites can be separated into ingredients of LT3K, which act to promote cell proliferation, and GT3K, which can be used to promote somatic cell reprogramming.

Tissue-specific effects of estrogen on glycerol channel aquaporin 7 expression in an ovariectomized mouse model of menopause

OBJECTIVE

Elevated fat mass and redistribution of body fat are commonly observed in postmenopausal women. Aquaporin 7 (AQP7), a unique glycerol permeable integral membrane protein, has been associated with the onset of obesity. We hypothesized that estrogen supplementation could counteract this fat accumulation and redistribution through tissue-specific modulation of AQP7.

METHODS

We measured fat depot weight, adipocyte size, and the expression of AQP7 and glycerol kinase (GK) in visceral and subcutaneous fat tissues of ovariectomized mice supplemented with or without 17β-estradiol.

RESULTS

Removal of the ovaries resulted in a significant decrease in AQP7 expression and an increase in GK expression in visceral adipocyte tissue; expression of AQP7 and GK in subcutaneous adipose tissue remained unaltered. Supplementation with estrogen significantly restored the visceral, but not subcutaneous, fat depot mass and adipocyte size to those of sham-operated mice. A marked increase in the expression of AQP7 and a reduction of GK were observed selectively in the visceral fat depots in estrogen-treated mice.

CONCLUSIONS

Our results suggest that estrogen has tissue-specific effects on AQP7 expression, and modulation of AQP7 by estrogen alters the balance of adipocyte metabolism between adipose tissue depots.

Asian Immigrant Settlement and Adjustment in Australia

Asians have been the fastest growing overseas-born population inAustralia, more than doubling from 1981 to 1991. Based on the 1991 Census, this article broadly examines economic and social characteristics of the Asian-born population in Australia. Economic factors such as labor force participation, unemployment, occupation, income and housing reveal a great diversity in the settlement experience of the Asian-born, attributable to the diversity of backgrounds. The speed and success of adjustment by refugees and migrants from business, skill and family migrant streams are assisted by such social factors as English language proficiency.

Pressure-dependent isotopic composition of iron alloys

Our current understanding of Earth's core formation is limited by the fact that this profound event is far removed from us physically and temporally. The composition of the iron metal in the core was a result of the conditions of its formation, which has important implications for our planet's geochemical evolution and physical history. We present experimental and theoretical evidence for the effect of pressure on iron isotopic composition, which we found to vary according to the alloy tested (FeO, FeH(x), or Fe3C versus pure Fe). These results suggest that hydrogen or carbon is not the major light-element component in the core. The pressure dependence of iron isotopic composition provides an independent constraint on Earth's core composition.

A glimpse into evolution and dissemination of multidrug-resistant Acinetobacter baumannii isolates in East Asia: a comparative genomics study

Clonal dissemination is characteristic of the important nosocomial pathogen Acinetobacter baumannii, as revealed by previous multi-locus sequence typing (MLST) studies. However, the disseminated phyletic unit is actually MLST sequence type instead of real bacterial clone. Here we sequenced the genomes of 13 multidrug-resistant (MDR) A. baumannii strains from Taiwan, and compared them with that of A. baumannii from other East Asian countries. Core-genome phylogenetic tree divided the analyzed strains into three major clades. Among them, one ST455 clade was a hybrid between the ST208 clade and the other ST455 clade. Several strains showed nearly identical genome sequence, but their isolation sources differed by over 2,500 km and 10 years apart, suggesting a wide dissemination of the phyletic units, which were much smaller than the sequence type. Frequent structural variation was detected even between the closely related strains in antimicrobial resistance elements such as AbaRI, class I integron, indicating strong selection pressure brought by antimicrobial use. In conclusion, wide clonal dissemination and frequent genomic variation simultaneously characterize the clinical MDR A. baumannii in East Asia.

Endometrial carcinoma tumorigenesis and pharmacotherapy research

Endometrial carcinoma is the common malignant tumor of the female genital tract, and its incidence is increasing. Two different clinicopathological subtypes are recognized based on epidemiology, genetic carcinogenesis and clinical behavior. Understanding and identifying molecular biology and genetics is essential to the development of novel therapies. This article reviews the current understanding of its risk factors, recent conceptions on its tumorigenesis and advances on its drug therapies.

[Application of susceptibility weighted imaging in revealing intratumoral blood products and grading gliomas]

OBJECTIVE

Susceptibility weighted imaging (SWI) is a novel imaging method that utilizes the magnetic susceptibility differences between tissues. The purpose of our study was to evaluate the application of SWI for revealing inratumoral blood products and diagnosing high-grade gliomas.

MATERIALS AND METHODS

Conventional MR sequences and SWI were performed in 32 patients, 10 low-grade gliomas (1 grade I and 9 grade II) and 22 high-grade gliomas (8 grade III and 14 grade IV). The ability of SWI for detecting inratumral blood products was analyzed and compared with conventional MR sequences. Logistic regression and Receiver operating characteristic (ROC) curve analysis were used to evaluate the diagnostic value of SWI for high-grade gliomas.

RESULTS

SWI was sensitive for showing intrtumoral blood products (P=0.00) and depicted much more micro bleeds. No statistical difference was found in detection rate of blood products between low-grade and high-grade group. According to the result of logistic regression, the frequency of blood products and the diameter of maximum blood products were significant determinants of high-grade gliomas. The result of ROC analysis indicated that with an optimal cut-off point (0.67), the sensitivity, specificity, positive predictive value and negative predictive value for diagnosing high-grade gliomas with blood products detected by SWI were 81.8%, 80.0%, 90.0%, and 66.6%, respectively.

CONCLUSION

SWI can accurately detect blood products with superlative contrast. With a high-grade gliomas risk estimation model based on two variables, satisfied sensitivity, specificity, PPV and NPV were obtained. Thus, SWI could be a useful adjunct sequence in glioma grading.

First Report of Citrus exocortis viroid from Grapevine in China

Citrus exocortis viroid (CEVd) can induce bark scaling, dwarfing, leaf epinasty, and fruit yield loss in susceptible hosts. In citrus, CEVd is reported from around the world, but in grape, it is reported from fewer locations (Australia, Brazil, California, and Spain [1]). In 2009, leaves were collected from 40 grapevines (of several different cultivars and species) from Henan, Hubei, Shandong, and Liaoning provinces, China. Total RNA or double-stranded RNA was extracted from the leaves by a described method (3) and subjected to reverse transcription with a random primer (Takara, Dalian, China) and then PCR with primer CEV-AM3 and CEV-AP3 (2). Results showed that the target DNA fragments of 372 bp long were amplified only from the symptomless leaves collected from two grapevines of cv. White Rose grown for approximately 26 years within a small garden in Hubei Province. Amplified products were recovered and cloned into pMD18-T (Takara) and 10 positive clones of each isolate were sequenced and aligned. For both isolates, 20% of the clones represented the same variant (CEVd-hn-g-1; GenBank Accession No. GU592444). It showed a max identity of 94 to 99% with the variants (GenBank Accession Nos. Y00328.1 and DQ471996.1) from grape registered in NCBI, 91 to 100% (GenBank Accession Nos. DQ431993.1 and DQ831485.1) from citrus, 91 to 98% (GenBank Accession Nos. EF488068.1 and EF488050.1) from broad bean, and 89 to 94% (GenBank Accession Nos. AY671953.1 and S67446.1) from tomato. To our knowledge, this is the first report of CEVd from grape in China. References: (1) M. Eiras et al. Fitopatol. Bras. 31:440, 2006. (2) H. J. Gross et al. Eur. J. Biochem. 121:249, 1982. (3) W. X. Xu et al. J. Virol. Methods 135:276, 2006.

Amino acid supplementation decreases plasmid retention in Escherichia coli

The effect of amino acid supplementation on plasmid stability in Escherichia coli B/r was tested experimentally. Comparisons of experimental results to computer-predicted values were made using a detailed, structured single-cell model. The plasmid, pDW17 (a pBR322 derivative with a mutated tac promoter controlling the beta-lactamase gene), was used. In chemostat cultures, the amino acid supplemented cultures were always less stable than those grown in minimal medium. This effect was not a growth rate effect, as increasing growth rate improves stability for both cultures in minimal medium and in amino acid supplemented medium. The computer model also predicted a decrease in stability due to amino acid supplementation. The model also predicts that amino acid supplementation, combined with moderately strong plasmid-encoded protein expression, results in a depletion of low-molecular-weight organics compared with plasmid-free cells. In minimal medium the same level of plasmid-encoded protein synthesis results in a strong reduction in amino acid pools compared with plasmid-free cells. With amino acid supplementation the growth differential between plasmid-bearing and plasmid-free cells may be due to an "energy limitation," while in minimal medium the size of the growth rate differential may be due to a "building block" limitation.

A mathematical model for the growth of a single cell of E. coli on a glucose/glutamine/ammonium medium

Extension of a single cell model of E. coli B/r to make predictions of culture response to variations in glutamine/glucose/ammonium ion concentrations is described. A biphasic glutamine transport system, a nitrogen metabolism scheme that includes glutamate dehydrogenase (GDH), glutamine synthetase/glutamate synthase (GS/GOGAT), the glutaminase routes, and a transaminase mechanism for glutamine carbon usage are added to the prototype model. The predictions of the extended model with regard to nutrient concentrations and cell size compare well with the experimental data and the prototype model predictions, demonstrating the capability of the integrated kinetic model to illustrate important enzymological interactions in a biological system. The discrepancies between the experimental data and the model predictions on growth yield suggest that a more detailed regulatory system of the TCA cycle is required for a more accurate energy budget.