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Objective To investigate the role and potential mechanism of high mobility group box-1 protein (HMGB1) on improving the chemosensitivity of gemcitabine-resistant pancreatic cancer PANC1 ceils.Methods Gemcitabine-resistant pancreatic cancer PANC1 (PANC1-GR) cell line was established by using increased gradient concentration of gemcitabine.The si-HMGB1-PANC1 and si-HMGB1-PANC1-GR cells were established by the transfection with HMGB1 siRNA using liposome.The 50％ inhibitory concentration (IC50) and Resistance index (RI) of gemcitabine in 4 PANC1 cell lines with or without HMGB1 siRNA transfection were determined and calculated by CCK-8 assay.Western blot assay was used to detect the protein expression of HMGB1 in PANC1 and PANC1-GR cells and the expression of autophagy marker protein Beclin1 in the 4 PANC1 cell lines.Flow cytometry assay was used to evaluate the apoptosis rate of 4 pancreatic caner cell lines.Results The gemcitabine-resistant pancreatic cancer cell line PANC1-GR was successfully established,which could grow stably and passage in media with 100 μmol/L gemcitabine.The IC50 of gemcitabine in PANC1,PANC1-GR,si-HMGB1-PANC1,and si-HMGB1-PANC1-GR cells lines were (4.7 ±0.4) μmoL/L,(166.5 ± 13.6) μmol/L,(3.2 ± 0.3) μmol/L,and (52.4 ± 8.4) μmol/L,respectively.The IC50 in PANC1-GR wassignificantly higher than that in PANC1,while the IC50 in the transfected cells was significantly lower than that in untransfected cells,and the differences were both statistically significant (bothP ＜ 0.01).The RI value of gemcitabine in transfected and untransfected PANC1-GR cells was 35.4 and 16.4.The relative protein levels of HMGB1 in PANC1 and PANC1-GR were 0.17 ± 0.08 and 0.38 ± 0.11.The expression of HMGB1 in PANC1-GR was obviously higher than that in PANC1,and the difference was statistically significant (P＜0.01).The relative protein levels of Beclin1 in PANC1,PANC1-GR,si-HMGB1-PANC1 and siHMGB1-PANC1-GR cells were 2.68 ± 0.23,3.28 ± 0.15,0.68 ± 0.23 and 0.78 ± 0.11,which in two transfected cells was greatly lower than those in untransfected cells.The apoptosis level was (34.58± 3.14)％,(79.56±3.58)％,(19.41± 1.53)％,and (34.57±2.94)％.The apoptosis level in the 2 transfected cell lines were significantly higher than those in the 2 untransfected cell lines,and the differences were both statistically significant (P ＜ 0.01).Conclusions The inhibition of HMGB1 could improve the chemosensitivity of gemcitabine in pancreatic cancer PANC1 cells,which might be mediated by the activation of autophagy.
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Objective To investigate the radiobiological effects of VPA-BSANPs on C6 and U87 glioma cells in vitro.Methods C6 and U87 glioma cells were treated with different concentrations of VPA and VPA-BSANPs for 12 h and 24 h,and MTT assay was used to determine cell viability.C6 and U87 cells were treated with different concentrations of VPA and VPA-BSANPs conbined with X-ray irradiation (0,2,4,6,and 8 Gy),and colony formation assay was used to determine plating efficiency (PE).C6 and U87 glioma cells were treated with different concentrations of VPA and VPA-BSANPs for 12 h,followed by X-ray irradiation (0,4,and 8 Gy),and flow cytometry using Annexin V-FITC/PI staining was used to examine cell apoptosis.Western blot was used to evaluate the effects of VPA and VPA-BSANPs on radiation-induced apoptosis protein expression.One-way ANOVA was used for comparison of means with homogeneity of variance between multiple groups,and the t-test was used for comparison of means between two groups.Results Without irradiation,VPA and VPA-BSANPs had no significant inhibitory effects on the proliferation of C6 and U87 cells (P=0.328,0.920).The PE of cells treated with VPA-BSANPs combined with irradiation was significantly lower than that of cells treated with VPA combined with irradiation (P=0.000).In C6 and U87 cells,VPA-BSANPs combined with irradiation increased the expression of p53 and Bax (P =0.000,0.000 and P =0.010,0.002),but reduced the expression of Bcl-2 (P =0.008,0.000).Active caspase-3 fragments were only found in the cells treated with VPA-BSANPs combined with irradiation and VPA combined with irradiation,but were less in the former cells than in the latter cells (P=0.004).The active fragments of peroxisome proliferator-activated receptor were only found in the cells treated with VPA-BSANPs combined with irradiation.Conclusions VPA-BSANPs can increase the radiosensitivity of C6 and U87 glioma cells in vitro,possibly by promoting the apoptosis of tumor cells induced by radiation.
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Objective To observe the regulatory role of long non-coding RNA HIF1A-AS1 on the autophagy of pancreatic cancer PANC1 cells induced by hypoxia.Methods The pancreatic cancer PANC1 cells were cultured in a three-gas incubator filled with hypoxic gas mixture (94% N2,5% CO2,1% O2) for 3, 6, 12, 24, 36 and 48 h.HIF1A-AS1 overexpression and low expression PANC1 cells were obtained by the infection of recombinant adenovirus carrying HIF1A-AS1 and the transfection of HIF1A-AS1 targeting siRNA by liposome, and routinely cultured PANC1 cells served as control.The expression of HIF1A-AS1 of PANC1 cells was detected by real-time quantitative PCR after being cultured in hypoxia-induced condition for 24 h.The apoptosis rate was detected by flow cytometry.The autophagy related proteins Beclin 1 were detected by western blot.Results The expression of HIF1A-AS1 in hypoxic cells was increased as the hypoxic time increased since 6 h and peaked at 36 h, which was significantly higher than that in control group (P<0.01).HIF1A-AS1 relative expression in HIF1A-AS1 overexpression and low expression PANC1 cells was 4.49±0.53 and 0.49±0.07, which were normalized to that of control group with the relative expression of 1.Control group had lower HIF1A-AS1 expression than HIF1A-AS1 overexpression PANC1 cells but higher HIF1A-AS1 in HIF1A-AS1 low expression PANC1 cells, and the differences were statistically significant (P<0.01).The cell apoptosis rate of control, HIF1A-AS1 overexpression and low expression PANC1 cells was (8.27±1.28)%, (6.56±1.49)% and (19.9±2.34)% after 24 h hypoxic culture.Control group had higher HIF1A-AS1 expression than HIF1A-AS1 overexpression PANC1 cells but lower HIF1A-AS1 in HIF1A-AS1 low expression PANC1 cells, and the differences were statistically significant (P<0.01).The expression of Beclin 1 protein was protein 1.05±0.11, 1.29±0.19 and 0.38±0.18, respectively.Control group had lower Beclin 1 expression than HIF1A-AS1 overexpression PANC1 cells but higher Beclin 1 in HIF1A-AS1 low expression PANC1 cells, and the differences were statistically significant (P<0.01).Conclusions HIF1A-AS1 can promote autophagy of pancreatic cancer PANC1 cells induced by hypoxia and participate in the pathogenesis and metastasis of pancreatic cancer.
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The image guided radio therapy (IGRT) Imaging System based on cone-beam computer tomography (CBCT) can reach the goal of improving the accuracy of the radiotherapy. However, because the clinical registration between CBCT images and Planning CT images is carried out manually, it inevitably reduces radiation positioning accuracy to some extent. To tackle the problem, we proposed a new feature vector selection method for the CBCT image elastic registration in the framework of hierarchical attribute matching mechanism for elastic registration (HAMMER) algorithm. We analyzed the characteristics of HAMMER algorithm and used Canny operator which has a better edge detection and positioning performance to replace the noise-sensitive gradient amplitude. Therefore, we used a new attribute vector, which consisted of the intensity, Laplacian of the Gaussian and Canny operator, to ex tract the image feature points in CBCT and planning CT images. We also presented an adaptive feature-point selection method and the choice criteria of attribute vector weights. Experimental results showed that the new feature vector effectively avoided the noise interference resulted from scattering lines in CBCT images to improve registration accuracy, and it also decreased the required feature point numbers and reduced the computation redundancy, so that it provided a new approach for the clinical elastic registration of CBCT and Planning CT rapidly and accurately.
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Humans , Algorithms , Cone-Beam Computed Tomography , Radiotherapy , Methods , Radiotherapy Planning, Computer-AssistedABSTRACT
BACKGROUND: Studies have demonstrated that trehalose possesses protective effects on cyropreserved sternum. But the mechanism of action remains poorly understood. OBJECTIVE: To investigate the effects of trehalose on bcl-2 and bax mRNA expression in cryopreserved sternum. METHODS: Four groups of freshly prepared solution were used: low-potassium dextran (LPD), LPD + dimethyl sulfoxide (DMSO), LPD + trehalose, LPD + DMSO + trehalose. Rat sternum was cut and then immediately cryopreserved in the tubes containing each group of solution. Fresh rat sternum tissue and 4 groups of samples cryopreserved for 120 days were taken and bcl-2 and bax mRNA expression in fresh and cryopreserved sternum was detected using reverse transcription-polymerase chain reaction.RESULTS AND CONCLUSION: bcl-2 mRNA expression in the LPD + trehalose group was significantly higher, but bax mRNA expression was significantly lower, than in the LPD, LPD + DMSO groups (both P 0.05). These findings indicate that trehalose may protect cell activity in cryopreserved sternum by enhancing bcl-2 mRNA expression and inhibiting bax mRNA expression, and trehalose together with DMSO shows better protective effects.
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Malignant tumor severely endangers the health of people. Scholars in and abroad believed that the causes of malignant tumor are related to people's mental disorder. Emotional imbalance had immediate influences in the whole process of tumor, including the occurrence, progressing, treatment, and recovery. Therefore, we should pay more attention to regulate the emotion for the patients with malignant tumor.
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The mollusicidal effect and toxicity to fish with META-Li in field were tested in mountain areas in Zhejiang Province. The snail control test, which had 3 groups including a META-Li group, niclosamide group and control group, were performed by the spraying method. The adjusted mortalities of snails in the META-Li group on the 3rd, 7th and 15th day were 89.76% , 87.98% and 94.10% , respectively, in the niclosamide group were 89.70% , 83.22% and 94.72% , respectively .and there was no significant difference between the two groups ( P > 0.05), but they were decreased obviously compared with the control group, which were 9.24% , 9.50% and 15.21% , respectively(P <0.05). The toxicity test to fish with META-Li included 3 groups, namely a high concentration META-Li group, low concentration META-Li group and control group, and none fish was dead. It is suggested META-Li has low toxicity to fish, and is suitable to snail control in aquiculture areas.