[Effects of simvastatin on the proliferation, invasion and radiosensitivity in Lewis lung cancer cell line]

Objective: To investigate the effects of simvastatin on proliferation, invasion and radiosensitivity of mouse Lewis lung cancer cell line in vitro. Methods: The inhibitory effects of simvastatin on proliferation of Lewis lung cancer cells were detected by MTT assay. Matrigel invasion and migration assay was used to determine the invasion and motility ability of the Lewis cells. P38 activity was measured by p38 activity detection kit, and the expressions of p-p38, MKP-1, RhoA and MMP-2 were analyzed by Western blot. Lung cancer xenograft model was established in C57BL/6 mice. The mice were randomly divided into control group, simvastatin group, radiotherapy alone group and combined treatment group. The mice were killed 27 days after inoculation. The tumor mass, volume and lung metastatic nodules in the mice were compared. Results: The cell proliferation rates of 0 μmol/L, 10 μmol/L, 20 μmol/L and 30 μmol/L simvastatin groups were 100%, (87.0±9.0)%, (76.5±8.1)% and (67.0±7.3)%, respectively (P<0.05). Invasive cell numbers of the above groups were 298±30, 251±26, 207±20 and 132±19 per field, respectively (P<0.05). The intracellular p38 activities were 100%, (83.1±8.8)%, (70.2±8.2)% and (59.0±6.4)%, respectively. The relative expressions of p-p38 were 100%, (76.2±6.7)%, (56.4±5.4)% and (36.5±3.2)%, respectively. The expressions of RhoA were 100%, (80.1±5.3)%, (55.3±6.2)% and (38.6±4.8)%, respectively. The expressions of MMP-2 were 100%, (89.6±8.6)%, (51.9±4.7)% and (42.7±3.1)%, respectively, while the expressions of MKP-1 were 100%, (136.5±12.2)%, (168.8±15.3)% and (187.7±13.4)%, respectively (all P<0.05). Lung metastatic nodules and mass in the control, simvastatin, radiotherapy group and combined treatment groups were 6.24±1.09, 3.07±0.71 g, 5.09±1.16, 2.43±0.53 g, 3.12±0.68, 1.96±0.62 g and 2.65±0.38, 1.12±0.43 g, respectively (all P<0.05). The tumor inhibition rates were 39.0%, 48.1% and 26.5%, respectively, in the radiotherapy alone, combined treatment and simvastatin groups (all P<0.05). Conclusions: Simvastatin inhibits the proliferation of Lewis cell line by inhibiting the activity of p38 and expression of p-p38. Meanwhile, simvastatin reduces the invasion and motility of Lewis cell line through down-regulating the expression of RhoA and MMP-2. When combined with radiotherapy, simvastatin can inhibit tumor growth and metastasis, and improve the treatment efficacy of radiotherapy synergistically.

[Relationship between the risk factors of coronary artery disease and degree of coronary artery plaques assessed by multi-detector row spiral computed tomography]

Objective: To assess the association of the traditional risk factors of coronary artery disease(CAD) and degree of coronary artery plaque. Methods: A total of 3 752 patients who had a suspicion of CAD from September 2011 to November 2012 at the First Hospital of China Medical University underwent the coronary artery computed tomography. The univariable and multivariable Logistic regression were employ to assess the association the traditional risk factors of CAD and degree of coronary artery plaque. Results: Age, diabetes, hypertension and smoking were the independent risk factor for significant stenosis, multivessel lesions and high coronary artery calcium score(all P <0.05), male was an independent risk factor for significant stenosis(P=0.039), however HDL-C was the independent protect factor(all P<0.05). Conclusion: Age, diabetes, hypertension and smoking are the independent risk factor for degree of coronary artery plaque, HDL-C is the independent protect factor.Male is only an independent risk factor for significant stenosis.

[Effect of endonuclease G depletion on plasmid DNA uptake and levels of homologous recombination in hela cells]

Endonuclease G (EndoG) is a mitochondrial apoptosis regulator that also has roles outside of programmed cell death. It has been implicated as a defence DNase involved in the degradation of exogenous DNA after transfection of mammalian cells and in homologous recombination of viral and endogenous DNA. In this study, we looked at the effect of EndoG depletion on plasmid DNA uptake and the levels of homologous recombination in HeLa cells. We show that the proposed defence role of EndoG against uptake of non-viral DNA vectors does not extend to the cervical carcinoma HeLa cells, as targeting of EndoG expression by RNA interference failed to increase intracellular plasmid DNA levels. However, reducing EndoG levels in HeLa cells resulted in a statistically significant reduction of homologous recombination between two plasmid DNA substrates. These findings suggest that non-viral DNA vectors are also substrates for EndoG in its role in homologous recombination.

Charged particle flows in the beam extraction region of a negative ion source for NBI

Experiments by a four-pin probe and photodetachment technique were carried out to investigate the charged particle flows in the beam extraction region of a negative hydrogen ion source for neutral beam injector. Electron and positive ion flows were obtained from the polar distribution of the probe saturation current. Negative hydrogen ion flow velocity and temperature were obtained by comparing the recovery times of the photodetachment signals at opposite probe tips. Electron and positive ions flows are dominated by crossed field drift and ambipolar diffusion. Negative hydrogen ion temperature is evaluated to be 0.12 eV.

Improvement of accelerator of negative ion source on the Large Helical Device

To improve the performance of negative-ion based neutral beam injection on the Large Helical Device, the accelerator was modified on the basis of numerical investigations. A field limiting ring was installed on the upper side of a grounded grid (GG) support and a multi-slot GG was adopted instead of a multi-aperture GG. As a result, the voltage holding capability is improved and the heat load on the GG decreases by 40%. In addition, the arc efficiency is improved significantly only by replacing the GG.

Installation of spectrally selective imaging system in RF negative ion source

A spectrally selective imaging system has been installed in the RF negative ion source in the International Thermonuclear Experimental Reactor-relevant negative ion beam test facility ELISE (Extraction from a Large Ion Source Experiment) to investigate distribution of hydrogen Balmer-α emission (Hα) close to the production surface of hydrogen negative ion. We selected a GigE vision camera coupled with an optical band-path filter, which can be controlled remotely using high speed network connection. A distribution of Hα emission near the bias plate has been clearly observed. The same time trend on Hα intensities measured by the imaging diagnostic and the optical emission spectroscopy is confirmed.

Negative ion production and beam extraction processes in a large ion source (invited)

Recent research results on negative-ion-rich plasmas in a large negative ion source have been reviewed. Spatial density and flow distributions of negative hydrogen ions (H(-)) and positive hydrogen ions together with those of electrons are investigated with a 4-pin probe and a photodetachment (PD) signal of a Langmuir probe. The PD signal is converted to local H(-) density from signal calibration to a scanning cavity ring down PD measurement. Introduction of Cs changes the slope of plasma potential local distribution depending upon the plasma grid bias. A higher electron density H2 plasma locally shields the bias potential and behaves like a metallic free electron gas. On the other hand, the bias and extraction electric fields penetrate in a Cs-seeded electronegative plasma even when the electron density is similar. Electrons are transported by the penetrated electric fields from the driver region along and across the filter and electron deflection magnetic fields. Plasma ions exhibited a completely different response against the penetration of electric fields.

Effects of curcumin on hippocampal expression of NgR and axonal regeneration in Aβ-induced cognitive disorder rats

Curcumin has been widely used for the prevention and treatment of Alzheimer's disease (AD), but its mechanism is still not clear. Inhibitory factors of axonal regeneration have been shown to cause a series of pathophysiological changes in the early period of AD. In this study, the co-receptor (Nogo receptor; NgR) of three axonal growth-inhibitory proteins was examined, and effects of curcumin on spatial learning and memory abilities and hippocampal axonal growth were investigated in amyloid β-protein (Aβ)1-40-induced AD rats. Results showed that the expression of NgR in the AD group significantly increased and the number of axonal protein-positive fibers significantly reduced. The spatial learning and memory abilities of AD rats were significantly improved in the curcumin group. Furthermore, hippocampal expressions of NgR mRNA and protein decreased, and the expression of axonal protein significantly increased. There was a negative correlation between the expression of NgR and axonal growth. Together, these results suggested that curcumin could improve the spatial learning and memory abilities of AD rats. The mechanism might be related with its lowering of hippocampal NgR expression and promoting axonal regeneration.

Upregulation of microRNA-224 confers a poor prognosis in glioma patients

OBJECTIVE

MicroRNA-224 (miR-224) has been consistently reported to be dysregulated in various human malignancies and can potentially affect many cancer-related cellular processes, including transcription, cell differentiation, cell death, growth, and cell proliferation. However, its roles in human glioma have not been reported. The aim of this study was to explore the expression pattern, clinical significance, and prognostic value of miR-224 in glioma patients using large cohorts.

METHODS

Quantitative real-time polymerase chain reaction analysis was used to characterize the expression patterns of miR-224 in 108 glioma and 20 normal brain tissues. The associations of miR-224 expression with clinicopathological factors and prognosis of glioma patients were also statistically analyzed.

RESULTS

miR-224 expression is significantly upregulated in glioma tissues compared with normal brain tissues (P < 0.001). In addition, high expression of miR-224 was significantly associated with advanced pathological grade (P = 0.006) and low Karnofsky performance score (KPS, P = 0.01). Moreover, Kaplan-Meier survival analysis showed that high miR-224 expression group had significantly shorter disease-free survival (DFS) and overall survival (OS) rates than low miR-224 expression group (both P < 0.001). Multivariate analysis with the Cox's proportional hazards model revealed that high expression of miR-224 (P = 0.006 and P = 0.01, respectively) and advanced pathological grade (both P = 0.02) were independent factors for shorter DFS and OS. Furthermore, subgroup analyses showed that miR-224 expression was significantly associated with poor DFS and OS in glioma patients with high pathological grades (for grade III-IV: P < 0.001 and P = 0.005, respectively).

CONCLUSIONS

MiR-224 is upregulated and confers a poor prognosis in glioma patients.

Human B-cell ontogeny in humanized NOD/SCID γc(null) mice generates a diverse yet auto/poly- and HIV-1-reactive antibody repertoire

Characterization of the human antibody (Ab) repertoire in mouse models of the human immune system is essential to establish their relevance in translational studies. Single human B-cells were sorted from bone marrow and periphery of humanized NOD/SCID γc^null mice at 8–10 months post-engraftment with human cord blood-derived CD34⁺ stem cells. Human immunoglobulin variable heavy (V_H) and kappa (V_κ) genes were amplified, cognate V_H-V_κ gene-pairs assembled as single-chain variable fragment-Fc antibodies (scFvFcs) and functional studies performed. Although overall distribution of V_H genes approximated the normal human Ab repertoire, analysis of the V_H-third complementarity determining regions (H-CDR3) in the mature B-cell subset demonstrated an increase in length and positive charges suggesting autoimmune characteristics. Additionally, >70% of V_κ sequences utilized V_κ4-1, a germline gene associated with autoimmunity. The mature B-cell subset-derived scFvFcs displayed the highest frequency of autoreactivity and polyspecificity, suggesting defects in checkpoint control mechanisms. Furthermore, these scFvFcs demonstrated binding to recombinant HIV envelope corroborating previous observations of poly/autoreactivity in anti-HIVgp140 antibodies. These data lend support to the hypothesis that anti-HIV BnAbs may be derived from auto/polyspecific Abs that escaped immune elimination and that the hNSG mouse could provide a new experimental platform for studying the origin of anti-HIV neutralizing Ab responses.

Salvage combination chemotherapy with floxuridine, dactinomycin, etoposide, and vincristine (FAEV) for patients with relapsed/chemoresistant gestational trophoblastic neoplasia

BACKGROUND

Although most patients with gestational trophoblastic neoplasia (GTN) are cured by conventional chemotherapy, some develop drug resistance or relapse. The use of new combination drugs has been studied to treat those with resistant or relapsed disease. We evaluated the results of floxuridine, dactinomycin, etoposide, and vincristine (FAEV) chemotherapy in patients with relapsed/chemoresistant GTN.

PATIENTS AND METHODS

Clinical data and outcome of the patients with relapsed/chemoresistant GTN from 1 January 2005 to 30 June 2008 were retrospectively reviewed. Eligible patients had received at least one cycle of FAEV chemotherapy. The primary end points were response rate and toxicity of FAEV regimen; the secondary end point was assessment of clinical predictors of response.

RESULTS

In total, 91 patients were included. Fifty-five of these patients (60.4%) achieved serologic complete remission (SCR), 29 patients had no response, 7 patients experienced recurrent grade ≥3 or intolerable toxicity. SCR of FAEV chemotherapy was significantly associated with number of previous chemotherapy regimens (≤2) in multivariate analysis (P = 0.005). The most serious adverse events were greater than or equal to grade 3 neutropenia (26.4%), febrile neutropenia (6.6%), and greater than or equal to grade 3 thrombocytopenia (3.3%).

CONCLUSION

FAEV is an effective regimen with manageable toxicity for patients with relapsed/chemoresistant GTN. Further studies of this regimen are warranted.