7-difluoromethoxyl-5,4'-di-n-octylgenistein inhibits growth of gastric cancer cells through downregulating forkhead box M1

AIM: To investigate whether the 7-difluoromethoxyl-5, 4'-di-n-octylgenistein (DFOG), a novel synthetic genistein analogue, affects the growth of gastric cancer cells and its mechanisms. METHODS: A series of genistein analogues were prepared by difluoromethylation and alkylation, and human gastric cancer cell lines AGS and SGC-7901 cultured in vitro were treated with various concentrations of genistein and genistein analogues. The cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cells were incubated by DFOG at different concentrations. The growth inhibitory effects were evaluated using MTT and clonogenic assay. The distribution of the phase in cell cycle was analyzed using flow cytometric analysis with propidium iodide staining. The expression of the transcription factor forkhead box M1 (FOXM1) was analyzed by reverse transcription-polymerase chain reaction and Western blotting. The expression levelsof CDK1, Cdc25B, cyclin B and p27KIP1 protein were detected using Western blotting. RESULTS: Nine of the genistein analogues had more effective antitumor activity than genistein. Among the tested analogues, DFOG possessed the strongest activity against AGS and SGC-7901 cells in vitro. DFOG significantly inhibited the cell viability and colony formation of AGS and SGC-7901 cells. Moreover, DFOG efficaciously arrested the cell cycle in G2/M phase. DFOG decreased the expression of FOXM1 and its downstream genes, such as CDK1, Cdc25B, cyclin B, and increased p27KIP1 at protein levels. Knockdown of FOXM1 by small interfering RNA before DFOG treatment resulted in enhanced cell growth inhibition in AGS cells. Up-regulation of FOXM1 by cDNA transfection attenuated DFOG-induced cell growth inhibition in AGS cells. CONCLUSION: DFOG inhibits the growth of human gastric cancer cells by down-regulating the FOXM1 expression.

Role of acoustic interface layer during high intensity focused ultrasound therapeutics

After interface layer was simulated by the magnetic nano-particles in the egg white phantom, high intensity focused ultrasound （HIFU） at the same dosage was introduced to radiate the phantom in different depths to blow the acoustic interface layer to mimic ＂point＂ exposure. The results showed that the volumes of biological focal region （BFR） were enlarged when the acoustic focal region （AFR） is close with interface layer. This meant that the magnetic nano-particles enhanced the therapeutic efficiency of HIFU. When the distance of the AFR from the interface layer was 10 mm, the size and shape of the BFR were similar with those of the control group, but a larger lesion at the interface, which was harmful for treatment, was observed. When the distance of the AFR to the interface layer increased to 30 mm, the size and shape of the BFR were also similar to those of the control group. When the thickness of the interface layer diminished, the utility of enhancement decreased. Continuous increase of the safe area for treatment and decrease of the utility of enhancement were observed along with the abatement of the thickness of the interface layer

Establishing an Initial Electron Beam Model with Monte Carlo Simulation for a Single 6 MV X-ray Medical Linac Based on Particle Dynamics Characteristics

Objective:In this study,we try to establish an initial electron beam model by combining Monte Carlo simulation method with particle dynamic calculation(TRSV)for the single 6 MV X-ray accelerating waveguide of BJ-6 medical linac.Methods and Materials:1.We adapted the treatment head configuration of BJ-6 medical linac made by Beijing Medical Equipment Institute(BMEI)as the radiation system for this study.2.Use particle dynamics calculation code called TRSV to drive out the initial electron beam parameters of the energy spectrum,the spatial intensity distribution,and the beam incidence angle.3.Analyze the 6 MV X-ray beam characteristics of PDDc,OARc in a water phantom by using Monte Carlo simulation(BEAMnrc,DOSXYZnrc)for a preset of the initial electron beam parameters which have been determined by TRSV,do the comparisons of the measured results of PDDm,OARm in a real water phantom,and then use the deviations of calculated and measured results to slightly modify the initial electron beam model back and forth until the deviations meet the error less than 2%.Results:The deviations between the Monte Carlo simulation results of percentage depth doses at PDDc and off-axis ratios OARc and the measured results of PDDm and OARm in a water phantom were within 2%.Conclusion:When doing the Monte Carlo simulation to determine the parameters of an initial electron beam for a particular medical linac like BJ-6,modifying some parameters based on the particle dynamics calculation code would give some more reasonable and more acceptable results.

Ginsenoside Rb1 improves energy metabolism after spinal cord injury

Mitochondrial damage caused by oxidative stress and energy deficiency induced by focal ischemia and hypoxia are important factors that aggravate diseases.Studies have shown that ginsenoside Rb1 has neurotrophic and neuroprotective effects.However,whether it influences energy metabolism after spinal cord injury remains unclear.In this study,we treated mouse and cell models of spinal cord injury with ginsenoside Rb1.We found that ginsenoside Rb1 remarkably inhibited neuronal oxidative stress,protected mitochondria,promoted neuronal metabolic reprogramming,increased glycolytic activity and ATP production,and promoted the survival of motor neurons in the anterior horn and the recovery of motor function in the hind limb.Because sirtuin 3 regulates glycolysis and oxidative stress,mouse and cell models of spinal cord injury were treated with the sirtuin 3 inhibitor 3-TYP.When Sirt3 expression was suppressed,we found that the therapeutic effects of ginsenoside Rb1 on spinal cord injury were remarkably inhibited.Therefore,ginsenoside Rb1 is considered a potential drug for the treatment of spinal cord injury,and its therapeutic effects are closely related to sirtuin 3.

Casticin-induced apoptosis involves death receptor 5 upregulation in hepatocellular carcinoma cells

AIM:To investigate the apoptotic activities of casticin in hepatocellular carcinoma(HCC) cells and its molecular mechanisms.METHODS:PLC/PRF/5 and Hep G2 cell lines were cultured in vitro and the inhibitory effect of casticin on the growth of cells was detected by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolim bromide(MTT) assay.The apoptotic cell death was examined using the cell apoptosis enzyme linked immunosorbent assay(ELISA) detection kit,flow cytometry(FCM) after propidium iodide(PI) staining and DNA agarose gel electrophoresis.The caspase activities were measured using ELISA.Reactive oxygen species(ROS) production was evaluated by FCM after dichlorodihydrofluorescein diacetate(DCFH-DA) probe labeling.Intracellular glutathione(GSH) content was measured using a glutathione assay kit.The expression of death receptor(DR)4 and DR5 proteins was analyzed by Western blotting and FCM.RESULTS:Casticin significantly inhibited the growth of human HCC(PLC/PRF/5 and Hep G2) cells in a dosedependent manner(P < 0.05).Casticin increased the percentage of the sub-G1 population in HCC cells in a concentration-dependent manner.The potency of casticin to PLC/PRF/5 cells was higher than that of 5-flurouracil(26.8% ± 4.8% vs 17.4% ± 5.1%) at 10 μmol/L for 24 h.Casticin increased the levels of Histone/DNA fragmentation and the levels of active caspase-3,-8 and-9 in a concentration-dependent manner(P < 0.05).Treatment with 30 μmol/L casticin for 24 h resulted in the formation of a DNA ladder.Casticin reduced the GSH content(P < 0.05),but did not affect the level of intracellular ROS in PLC/PRF/5 and Hep G2 cells.The thiol antioxidants,acetylcysteine(NAC) and GSH restored GSH content and attenuated casticin-induced apoptosis.In contrast,the nonthiol antioxidants,butylated hydroxyanisole and mannitol failed to do so.In the HCC cells treated with casticin for 24 h,DR5 protein level was increased.The expression of DR5 protein induced by casticin was inhibited by NAC.Pretreatment with DR5/Fc chimera protein,a blocking antibody,effectively attenuated the induction of apoptosis by casticin.CONCLUSION:Casticin-induced apoptosis of HCC cells is involved in GSH depletion and DR5 upregulation.

Study on Multi-Exponential Inversion Method for NMR Relaxation Signals with Tikhonov Segularization

The analysis of NMR data in terms of inversion of relaxation distribution is hampered by the ill-posed nature of the required solution about the Fredholm integral equation. Naive approaches such as multi-exponential fitting or standard least-squares algorithms are numerically unstable and often failed. This paper updates the application of Tikhonov regularization to stabilize this numerical inversion problem and demonstrates the method for automatically choosing the optimal value of the regularization parameter. The approach is computationally efficient and easy to implement using standard matrix algebra techniques, which is based on mathematical ware MATLAB. Example analyses arepresented using both synthetic data and experimental results of NMR studies on the liquid samples like as oils and yoghurt.

Cell sheet formation enhances the therapeutic effects of human umbilical cord mesenchymal stem cells on myocardial infarction as a bioactive material

Stem cell-based therapy has been used to treat ischaemic heart diseases for two decades.However,optimal cell types and transplantation methods remain unclear.This study evaluated the therapeutic effects of human umbilical cord mesenchymal stem cell(hUCMSC)sheet on myocardial infarction(MI).Methods:hUCMSCs expressing luciferase were generated by lentiviral transduction for in vivo bio-luminescent imaging tracking of cells.We applied a temperature-responsive cell culture surface-based method to form the hUCMSC sheet.Cell retention was evaluated using an in vivo bio-luminescent imaging tracking system.Unbiased transcriptional profiling of infarcted hearts and further immunohistochemical assessment of monocyte and macrophage subtypes were used to determine the mechanisms underlying the therapeutic effects of the hUCMSC sheet.Echocardiography and pathological analyses of heart sections were performed to evaluate cardiac function,angiogenesis and left ventricular remodelling.Results:When transplanted to the infarcted mouse hearts,hUCMSC sheet significantly improved the retention and survival compared with cell suspension.At the early stage of MI,hUCMSC sheet modulated inflammation by decreasing Mcp1-positive monocytes and CD68-positive macrophages and increasing Cx3cr1-positive non-classical macrophages,preserving the cardiomyocytes from acute injury.Moreover,the extracellular matrix produced by hUCMSC sheet then served as bioactive scaffold for the host cells to graft and generate new epicardial tissue,providing mechanical support and routes for revascularsation.These effects of hUCMSC sheet treatment significantly improved the cardiac function at days 7 and 28 post-MI.Conclusions:hUCMSC sheet formation dramatically improved the biological functions of hUCMSCs,mitigating adverse post-MI remodelling by modulating the inflammatory response and providing bioactive scaffold upon transplantation into the heart.Translational perspective:Due to its excellent availability as well as superior local cellular retention and survival,allogenic transplantation of hUCMSC sheets can more effectively acquire the biological functions of hUCMSCs,such as modulating inflammation and enhancing angiogenesis.Moreover,the hUCMSC sheet method allows the transfer of an intact extracellular matrix without introducing exogenous or synthetic biomaterial,further improving its clinical applicability.