Multicomponent Assessment of the Geometrical Uncertainty and Consequent Margins in Prostate Cancer Radiotherapy Treatment Using Fiducial Markers

The aim is to compute all sources of geometrical uncertainty in prostate radiotherapy using fiducial markers and determine the safety treatment margins. Based on the markers position, correlations between prostate rotation/deformation and rectal and bladder fillings as well as changes in prostate volume during the treatment course are analyzed. The study includes 375 pre-treatment CBCT images from 15 prostate cancer patients treated with hypofractionated radiotherapy. The position coordinates of the markers were obtained from each image acquisition. In addition, rectum and bladder were outlined on CBCTs. The intrafractional error was estimated by an additional post-treatment CBCT acquired on alternate days. Tau-Kendall analysis was performed to correlate organ fillings with prostate rotation/deformation. Delineation uncertainty was assessed from contours of 10 patients performed by two radiation oncologists and repeated twice. The CT contouring was assisted by a multiparametric MR approach combining a T2-weighted with diffusion-weighted imaging, and a gradient recalled echo for fiducial marker identification. Uncertainty associated to treatment unit was estimated from phantom measurements. The obtained clinical margins were 4.4, 7.3, 5.1 mm in the Left-Right, Superior-Inferior, and Anterior-Posterior directions, respectively, being the contouring the most important contribution. The mechanical limitations of the beam delivery system and the associated imaging device entailed errors of the same order as prostate motion, rotation or deformation. Weak correlations between variation of the rectal volume and the presence of rotations/deformations were found (correlation coefficient 0.182, p = 0.001 for rotations around lateral axis;correlation coefficients 0.1, p < 0.05 for deformations). The distance between markers decreased with session number, becoming more pronounced from fraction 13 and reaching 1 - 1.8 mm at the end of the treatment. In summary we have determined the optimal treatment margins based on geometrical uncertainty assessment using van Herk formalism. An appropriate preparation of rectum and bladder involves minimizing the effect of prostate rotations/deformations. The prostate tends to decrease in size during the treatment which could influence treatment re-planning strategies.

Enhancer of zeste homolog 2 contributes to apoptosis by inactivating janus kinase 2/signal transducer and activator of transcription signaling in inflammatory bowel disease

BACKGROUND Inflammatory bowel disease(IBD)is a prevalent worldwide health problem featured by relapsing,chronic gastrointestinal inflammation.Enhancer of zeste homolog 2(EZH2)is a critical epigenetic regulator in different pathological models,such as cancer and inflammation.However,the role of EZH2 in the IBD development is still obscure.AIM To explore the effect of EZH2 on IBD progression and the underlying mechanism.METHODS The IBD mouse model was conducted by adding dextran sodium sulfate(DSS),and the effect of EZH2 on DSS-induced colitis was assessed in the model.The function of EZH2 in regulating apoptosis and permeability was evaluated by Annexin V-FITC Apoptosis Detection Kit,transepithelial electrical resistance analysis,and Western blot analysis of related markers,including Zona occludens 1,claudin-5,and occludin,in NCM460 and fetal human colon(FHC)cells.The mechanical investigation was performed by quantitative reverse transcriptionpolymerase chain reaction,Western blot analysis,and chromatin immunoprecipitation assays.RESULTS The colon length was inhibited in the DSS-treated mice and was enhanced by the EZH2 depletion in the system.DSS treatment caused a decreased histological score in the mice,which was reversed by EZH2 depletion.The inflammatory cytokines,such as tumor necrosis factor-α,interleukin-6,and interleukin-1β,were induced in the DSS-treated mice,in which the depletion of EZH2 could reverse this effect.Moreover,the tumor necrosis factor-αtreatment induced the apoptosis of NCM460 and FHC cells,in which EZH2 depletion could reverse this effect in the cells.Moreover,the depletion of EZH2 attenuated permeability of colonic epithelial cells.Mechanically,the depletion of EZH2 or EZH2 inhibitor GSK343 was able to enhance the expression and the phosphorylation of janus kinase 2(JK2)and signal transducer and activator of transcription in the NCM460 and FHC cells.Specifically,EZH2 inactivated JAK2 expression by regulating histone H3K27me3.JAK2 inhibitor TG101348 was able to reverse EZH2 knockdownmediated colonic epithelial cell permeability and apoptosis.CONCLUSION Thus,we concluded that EZH2 contributed to apoptosis and inflammatory response by inactivating JAK2/signal transducer and activator of transcription signaling in IBD.EZH2 may be applied as a potential target for IBD therapy.

Icaritin Attenuates Lipid Accumulation by Increasing Energy Expenditure and Autophagy Regulated by Phosphorylating AMPK

Background and Aims:Lipid accumulation is the major characteristic of non-alcoholic fatty liver disease,the prevalence of which continues to rise.We aimed to investigate the effects and mechanisms of icaritin on lipid accumulation.Methods:Cells were treated with icaritin at 0.7,2.2,6.7,or 20μM for 24 h.The effects on lipid accumulation in L02 and Huh-7 cells were detected by Bodipy and oil red O staining,respectively.Mitochondria biogenesis of L02 cells was detected by MitoTracker Orange staining.Glucose uptake and adenosine triphosphate content of 3T3-L1 adipocytes and C2C12 myotubes were detected.The expression levels of proteins in the adenosine 5′-monophosphate-activated protein kinase(AMPK)signaling pathway,biomarkers of autophagy,and mitochondria biogenesis were measured by western blotting.LC3 puncta were detected by immunofluorescence.Results:Icaritin significantly attenuated lipid accumulation in L02 and Huh-7 cells and boosted the mitochondria biogenesis of L02 cells.Icaritin enhanced glucose uptake,decreased adenosine triphosphate content,and activated the AMPK signaling pathway in 3T3-L1 adipocytes and C2C12 myotubes.Icaritin boosted autophagy and also enhanced the initiation of autophagic flux in 3T3-L1 preadipocytes and C2C12 myoblasts.However,icaritin decreased autophagy and promoted mitochondria biogenesis in 3T3-L1 adipocytes and C2C12 myotubes.Conclusions:Icaritin attenuates lipid accumulation by increasing energy expenditure and regulating autophagy by activating the AMPK pathway.

Salicylic acid sensitizes cervical cancer cells to radiotherapy by activating AMPK/TSC2/mTOR pathway

Objective:To investigate the radio-sensitizing effect of salicylic acid(SA)on human cervical cancer cells and its potential molecular mechanism.Methods:Cervical cancer cells were treated with SA and ionizing radiation.The expression ofγ-H2AX was evaluated by immunofluorescence(IF)assay.Cell cycle and apoptosis were analyzed by flow cytometry.Western blot was performed to detect the protein level of AMPK/TSC2/mTOR pathway.Results:SA inhibited basal proliferation of cervical cancer cells in a dose and time dependent manner.In addition,SA increased radiation-induced DNA damage,promoted apoptosis,triggered a redistribution of cell cycle from G2-M phase to G1-S phase of cervical cancer cells,and hence increased cell sensitivity to radiation.Moreover,SA treatment elevated the expression levels of p-AMPKα(t=3.996,P<0.05)and p-TSC2(t=5.308,P<0.05),whereas the level of p-mTOR(t=10.160,P<0.05)was significantly decreased.Conclusion:SA enhances the radiosensitivity of cervical cancer cells by targeting AMPK/TSC2/mTOR signaling pathway,and might serve as a promising therapeutic strategy to improve the efficacy of radiotherapy for cervical cancer.