UBE2S, a novel substrate of Akt1, associates with Ku70 and regulates DNA repair and glioblastoma multiforme resistance to chemotherapy

Glioblastoma multiforme (GBM) is the most common primary malignant brain cancer in adults. However, the molecular events underlying carcinogenesis and their interplay remain elusive. Here, we report that the stability of Ubiquitin-conjugating enzyme E2S (UBE2S) is regulated by the PTEN/Akt pathway and that its degradation depends on the ubiquitin-proteasome system. Mechanistically, Akt1 physically interacted with and phosphorylated UBE2S at Thr 152, enhancing its stability by inhibiting proteasomal degradation. Additionally, accumulated UBE2S was found to be associated with the components of the non-homologous end-joining (NHEJ) complex and participated in the NHEJ-mediated DNA repair process. The association of Ku70 with UBE2S was enhanced, and the complex was recruited to double-stranded break (DSB) sites in response to etoposide treatment. Furthermore, knockdown of UBE2S expression inhibited NHEJ-mediated DSB repair and rendered glioblastoma cells more sensitive to chemotherapy. Overall, our findings provide a novel drug target that may serve as the rationale for the development of a new therapeutic approach.

Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200  GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12<p_{T}<50  GeV/c, within a pseudorapidity acceptance of |η|<0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

Cross-sectional survey on public health informatics workforce in China: issues, developments and the future

OBJECTIVE

To explore the current situation and issues related to the development of the public health informatics (PHI) workforce in provincial and prefectural centers for disease control and prevention (CDCs) in China, and to describe the corresponding strategies to address these issues for the future.

STUDY DESIGN

National cross-sectional study.

METHODS

One thousand two hundred and eighty-one respondents were selected at random from provincial and prefectural CDCs. The survey used a self-administered, structured questionnaire with an online data collection tool that integrated data quality control and user management. The questionnaire was divided into seven main categories. Score percentage of satisfaction and proportion in each part were calculated. Descriptive statistics were used to analyse the data, stratifying by country region, CDC level, job role and educational level.

RESULTS

One hundred and sixty staff from provincial CDCs and 1121 staff from prefectural CDCs were selected. Only 7.4% (33/445) of prefectural CDCs were not involved in this survey, due to lack of PHI practitioners. CDC staff in the eastern region were predominantly aged 30-39 years (39.5%), which was much younger compared with the other regions (P = 0.0012). Only 34 respondents (2.7%) had academic majors in both health and information technology. More staff had Master's degrees and a higher level of education (18.7%) in the eastern region compared with the other regions (P < 0.0001). Staff in the eastern region in high-level positions and with a higher level of education were more knowledgeable about PHI strategy. Prefectural CDC staff were more satisfied with their work and training than provincial CDC staff. In the eastern region, 34.9% of staff were hired through competitive recruitment, and 57.8% of staff had received a job description with detailed information about their responsibilities, which was higher than in the other regions. Staff in the western region were more likely to leave if a better job became available (37.7%) compared with staff in the other regions (P = 0.0116).

CONCLUSION

This study found regional disparities in PHI workforce development, possibly related to disparities in overall regional development. Findings showed a severe shortage of staff with a background in PHI, and occupational development paths were clearly lacking. Based on this study of current workforce issues, a comprehensive strategy for PHI workforce development in China has been described.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

New erythromycin derivatives enhance β-lactam antibiotics against methicillin-resistant Staphylococcus aureus

Newly synthesized erythromycin derivatives were screened for synergy with oxacillin and other β-lactam antibiotics against methicillin-resistant Staphylococcus aureus (MRSA). MRSA ATCC43300 and some clinically isolated MRSA were used. Several erythromycin derivatives were found to possess high synergism with oxacillin against MRSA. The newly synthesized erythromycin derivatives were also tested for their inhibitory effects against MRSA, either separately or in combination with oxacillin, using serial broth dilution, disc diffusion, Etest strips, growth curves and time-kill curves. A representative derivative, SIPI-8294, could potentiate almost all β-lactam antibiotics tested against the model strain MRSA ATCC43300 from 4 to 128 times and had synergism with oxacillin against 12 of 16 clinical isolates of MRSA under one-fourth of the minimum inhibitory concentration (MIC) of the compounds. This is the first report on the synergistic activity of these new erythromycin derivatives. These findings provide a new choice for the treatment of infection caused by MRSA and lead us to further study the synergistic mechanism.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first report on the synergy of anti-MRSA between new erythromycin derivatives and β-lactam antibiotics in vitro. The results show that although the erythromycin derivatives have poor anti-MRSA effects alone, they possess high synergism with oxacillin against MRSA ATCC43300 and clinically isolated MRSA. These novel compounds can significantly reduce the dosage of β-lactam antibiotics against MRSA, while this synergistic effect is different from the combination of β-lactams and β-lactamase inhibitors. The research may provide a new choice for the treatment of infection caused by MRSA and be useful to the research and development of new combination of medicines.

Effect of intra-abdominal volume increment on lungs in hemorrhagic shock

PURPOSE

Intra-abdominal hypertension (IAH) causes lung dysfunction in patients after hemorrhagic shock resuscitation. We performed intra-abdominal volume increment (IAVI) to IAH and studied its effect on pulmonary function.

METHODS

Eight minipigs established for IAH model by exsanquination until shock, incomplete blockage of portal vein and overload resuscitation were randomly divided into IAVI group (n=4) and sham-operated control group (n=4). Bladder pressure, arterial blood gas analysis and thoraco-abdominal computed tomography (CT) scans were measured. The minipigs were sacrificed 26 h after surgery, and lung samples were harvested for measuring the wet-to-dry weight ratio and hematoxylin-eosin staining.

RESULTS

Compared with sham-operated control group, the respiratory rate and paCO2 remarkably decreased and paO2 notably increased at 8 and 12 h in the IAVI group. The bladder pressure also notably decreased at 8, 12, and 22 h after IAVI treatment. However, a significant improvement in diaphragm height was observed at 22 h after IAVI treatment. The wet-to-dry weight ratio of the lungs in IAVI group was also significantly higher than that that in the sham-operated control group.

CONCLUSION

Our data indicate that IAVI surgery could improve the damaged pulmonary function caused by IAH after hemorrhagic shock resuscitation (Tab. 1, Fig. 7, Ref. 21).

Spontaneous neuronal activity predicts intersubject variations in executive control of attention

Executive control of attention regulates our thoughts, emotion and behavior. Individual differences in executive control are associated with task-related differences in brain activity. But it is unknown whether attentional differences depend on endogenous (resting state) brain activity and to what extent regional fluctuations and functional connectivity contribute to individual variations in executive control processing. Here, we explored the potential contribution of intrinsic brain activity to executive control by using resting-state functional magnetic resonance imaging (fMRI). Using the amplitude of low-frequency fluctuations (ALFF) as an index of spontaneous brain activity, we found that ALFF in the right precuneus (PCUN) and the medial part of left superior frontal gyrus (msFC) was significantly correlated with the efficiency of executive control processing. Crucially, the strengths of functional connectivity between the right PCUN/left msFC and distributed brain regions, including the left fusiform gyrus, right inferior frontal gyrus, left superior frontal gyrus and right precentral gyrus, were correlated with individual differences in executive performance. Together, the ALFF and functional connectivity accounted for 67% of the variability in behavioral performance. Moreover, the strength of functional connectivity between specific regions could predict more individual variability in executive control performance than regionally specific fluctuations. In conclusion, our findings suggest that spontaneous brain activity may reflect or underpin executive control of attention. It will provide new insights into the origins of inter-individual variability in human executive control processing.

TSG-6 mediates the effect of tendon derived stem cells for rotator cuff healing

BACKGROUND

Bone marrow stem cells (MSCs) were able to reduce fibrovascular tissues formation via TNF alpha-stimulated gene/protein 6 (6TSG-6) in various animal models. At the same time, tendon-derived stem cells (TDSCs) were able to promote rotator cuff healing; however, the mechanism is still unknown.

AIM

To investigate the role of TSG-6 in the treatment of rotator cuff healing with TDSCs.

MATERIALS AND METHODS

45 rats underwent unilateral detachment and repair of the supraspinatus tendon. 15 animals received TDSCs in a fibrin glue carrier(Group A), 15 received TSG-6 silenced TDSCs (Group B), and 15 received fibrin glue for control (Group C). Animals were sacrificed at 4 weeks and evaluated for the biomechanical testing. Statistical analysis was performed with an independent t test with significance set at p = 0.05.

RESULTS

The ultimate stress was greater in the TDSCs group (4.91 ± 1.41 N/mm(2)) as compared with the Control group (2.99 ± 1.04 N/mm(2)) (p < 0.05). However, when silent the expression of TSG-6, the TSG-6 silenced group (3.36 ± 0.96 N/mm(2)) showed no benefit over the control group (p = 0.32).

CONCLUSIONS

TSG-6 mediates the function of TDSCs to improve the structure and the attachment strength of the healing tendon-bone interface.

Therapeutic and preventive effects of an epidermal growth factor receptor inhibitor on oral squamous cell carcinoma

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is the sixth most common human neoplasm worldwide. Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is highly expressed in human OSCC and is a target for cancer therapy and prevention. This study investigated the therapeutic and preventive effects of an inhibitor of EGFR (PD153035) on OSCC.

METHODS

The effects of PD153035 were examined in human cancer cell lines in vitro, in an athymic nude mouse xenograft model in vivo, and in the 7,12-dimethyl benz[a]anthracene (DMBA)-induced hamster cheek pouch tumour model in vivo.

RESULTS

PD153035 significantly inhibited cell growth, delayed cell cycle progression and induced apoptosis in human OSCC cells in vitro. In vivo, PD153035 inhibited xenograft tumour growth in nude mice in a dose-dependent manner and prevented the development of OSCC at the postinitiation stage in the DMBA-induced hamster cheek pouch tumour model. PD153035 inhibited the DMBA-induced increases in cell proliferation and in levels of phosphorylated EGFR and phosphorylated signal transducer and activator of transcription 3 (STAT3) protein in the hamster cheek pouch.

CONCLUSIONS

Inhibitors of EGFR, such as PD153035, have potential value in the treatment and prevention of OSCC.