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This study was designed to explore the mechanism of Coix seed oil (Coix) impact on the drug resistance, bioluminescence imaging (BLI) and the efflux of D-luciferin potassium salt, the substrate of ABC transporters, in doxorubicin-resistant breast cancer cells. Multidrug resistance (MDR) gene and protein expression were analyzed in the cells by q-PCR and Western blot. First, in order to investigate the effect of the efflux function by ABC protein, a cell line with overexpressed luciferase was established in MCF-7 cell line. BLI was used to monitor the efflux kinetics of D-luciferin potassium salt before and after Coix treament. The results showed that the efflux of D-fluorescein potassium from MCF-7/DOXFluc was lessened when pretreated with Coix, which means that Coix may decrease the efflux of other chemotherapies using ABC transporters. Both of the results of q-PCR and Western blot showed that gene and protein expression of ABC transporters such as ABCG2, ABCC1 and ABCB1 were down-regulated by Coix treatment. The efficacy of Coix reversing MDR was verified with the chemotherapy medication doxorubicin (DOX). MTT assay showed that Coix increased the inhibitory effect of DOX on proliferation of MCF-7/DOX, and the optimal combination of ratio was 25 times that of DOX. The results suggest that Coix may reverse MDR of the substrate of ABC transporters from two aspects, one is to cut down the ABC protein efflux function, and the other is to decrease the quantity of ABC gene and protein expression.
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AIM To study the effects of Elemene Injection (ELE) on the kinetics of intracellular transport of Gefitinib (GEF) in PC-9/GR cells and to probe the role of ELE in reversing oncological multidrug resistance.METHODS The intracellular pharmacokinetic behavior of D-luciferin potassium salt,a substrate of an ATP-binding cassette (ABC) protein,was investigated in PC-9/GRFluc cells using real-time bioluminescence imaging.The resistance of PC-9/GR cells to GEF was determined by MTT assay.Compusyn software was used to analyze the synergistic effect of GEF and ELE,and HPLC to detect the uptake of GEF in PC-9/GR cells.RESULTS The respective GEF IC50 values of 0.01 μg/mL in PC-9 cells and 1.50 μg/mL in PC-9/GR cells revealed the 150 times drug resistance of PC-9/GR to PC-9 cells.The significantly enhanced intracellular fluorescence intensity of D-fluorescein potassium salt by the intervention of ELE also indicated remarkable GEF uptake increase in PC-9/GR cell line (P ＜ 0.05) due to the synergistic result.CONCLUSION Partly as the mechanism in reversing oncological multidrug resistance,ELE,a booster for the fluorescence intensity of D-luciferin potassium salt,promotes cellular uptake of GEF by inhibiting efflux function of ABC proteins.
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Objective To establish a mouse model of lung adenocarcinoma brain metastasis with human luc+-PC?9 cells stably expressing luciferase and to compare the evaluation values of bioluminescence imaging and18 F?FDG ( 18 F?flu?orodeoxyglucose) SPECT/CT in these models. Methods Suspension of luc+?PC?9 cells was injected into the left ventri?cle of BALB/c nude mice to establish a mouse model of brain metastasis from lung cancer. Bioluminescence imaging and18 F?FDG SPECT/CT were used to evaluate the metastasis of tumors as compared with HE?staining pathology as a golden standard. Results The success rate of brain metastases was 85% through injecting luc+?PC?9 cells into the left ventricle. The number of tumor cells was positively related to the intensity of light, with a linear correlation (R2 =0. 96). Fluores?cence was observed in the brain, spine and femur by bioluminescence imaging, and the metastases were confirmed by H&E pathological examination. 18 F?FDG SPECT/CT observed abnormal density collective foci in the spine or femur but not in the brain. Conclusions Injection of tumor cell suspension into the mouse left ventricle is a good method to establish a brain metastasis of lung cancer. Bioluminescence has a higher sensitivity and specificity in detecting brain metastasis and bone metastasis, with advantages of real?time, dynamical and non?invasive detection of tumor metastasis growth. 18 F?FDG SPECT/CT does not have superiority in detection of brain metastases but is suitable for detecting bone metastasis.
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Objective To construct a mouse model for real-time,noninvasive and specific monitoring of inflammation activation in hepatic tissues.Methods An inflammation reporter gene was targeted to the liver by hydrodynamic gene delivery technology.Bioluminescence imaging was used to detect the firefly luciferase(Fluc) expression in the mouse liver after inflammatory stimulation.Besides,the relevance between the light intensity and inflammation level was also intensively investigated.Results pIL-6-Fluc was successfully delivered to the liver.The hydrodynamic gene delivery could cause a transient liver injury that could return normal in 5 to 7 days.The expression of pIL-6-Fluc could be induced by lipopolysaccharides(LPS) treatment with an about (46.80±13.35) fold increase at the peak value,which was significantly higher than that detected by ELISA [(4.09±0.96)fold].Conclusion An inflammation reporter mouse model is constructed in this study by hydrodynamic gene transfection,allowing noninvasive monitoring of inflammation activation specifically in hepatic tissues.The reporter model is capable of monitoring inflammation activation with a sensitivity higher than that of ELISA.
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Objective:To study the signal enhancement of lung adenocarcinoma nude mice after injection of immunomagnetic bead solution (magnetic beads conjugated with monoclonal antibody NJ001) in micro-CT scan. Methods:The models of lung adenocarcino-ma nude mice were established by injecting SPC-A1-luc cells through the tail vein and were validated by bioluminescence imaging (BLI). The nude mice were divided into three groups: physiological saline group, bare magnetic bead group, and immunomagnetic bead group. Three groups of nude mice were injected with physiological saline, 750 nm bare magnetic bead solution, and immuno-magnetic bead solution via the tail vein every week, and micro-CT scan was taken before and 4 h after injection. Immunohistochemis-try (IHC) was used to detect the expression of antigen SP70 in tumor tissues. Results:The tumor was detected in the immunomagnetic bead group at the fourth week, whereas in the physiological saline and bare magnetic bead groups, the tumor was undetectable until the sixth week. The tumor intensities detected at the sixth week by micro-CT scan in the physiological saline, bare magnetic bead, and immunomagnetic bead groups were 59.05 ± 0.66, 60.69 ± 0.55, and 58.25 ± 0.32 before injection and 60.30 ± 1.83, 61.05 ± 0.68, and 67.41±3.82 after injection, respectively. Compared with the tumor intensities before injection, they significantly increased after injec-tion in the immunomagnetic bead group;the difference was statistically significant (P=0.0079). By contrast, no statistical significance was observed in the tumor intensities before and after injection in the physiological saline and bare magnetic bead groups (P=0.1867 and P=0.3839, respectively). Conclusion:The immunomagnetic beads had enhanced effect on micro-CT scan of lung adenocarcinoma nude mouse models.
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Objective To establish a luciferase labeled McA-RH7777 hepatoma rat model,which could be used for gross observation to further observe the effect of selective ligation of the portal vein and bile duct on tumor growth and metastasis.Methods The luciferase gene was transfected into rat McA-RH7777 hepatoma cells with pCDH-puromycin-CMV as the carrier,which were subcutaneously inoculated into Buffalo rats.Tumor pieces were then heterotransplanted into the left lateral lobe of the allogenic rat liver to observe the tumor growth in vivo.After the successful hepatoma modeling,the rats were randomly divided into three groups,namely the implanted portal vein group with combined portal vein and bile duct ligation,the implanted portal vein group with single portal vein ligation and sham operation group.The rats were executed at the 1 st week and 2nd week after ligation,and the livers were dissected to record the tumor growth and metastasis inside and outside the liver,respectively.Results The tumor formation rates of Buffalo rats after subcutaneous and intrahepatic implantation were both 100％.The fluorescence signal implanted into the liver lobe could be observed in vivo after the intrahepatic implantation of luciferase transfected Luc-McA-RH7777 at 2nd week,the range and intensity of which increased over time.Only local tumor growth could be found at the 4th week,without obvious intrahepatic and lung metastasis.However,both an increased in situ tumor volume and the pulmonary metastasis could be observed in the implanted portal vein group with combined portal vein and bile duct ligation at 2nd week after the ligation.Immunohistochemistry showed AFP positive immunoreactions in the vast majority of intrahepatic tumor cells and Luc positive immunoreactions in part of tumor cells.Conclusion Luc-McA-RH7777 cells could be used to establish the heptoma rat model and the in vivo analysis within the Buffalo rat liver demonstrated that the combined ligation of the portal vein and bile duct can accelerate the development and metastasis of liver cancer.
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Objective To develop a specific trans-splicing intron ribozyme type Ⅰ-mediated dual reporter gene system (Rib53-Fluc-tk) for targeting CEA.Methods The novel CEA-targeting trans-splicing ribozyme with the downstream reporter system (Rib53-Fluc-tk) was constructed by genetic engineering technology.The trans-splicing reaction product was evaluated using the 131I-5-iodo-2'-fluro-l-beta-D-arabinofuranosy-luracil (FIAU) cellular uptake rates and the bioluminescence.Two-sample t test,the analysis of variance and the least significant difference (LSD) t test was performed for data analysis.Results The sequence of Rib53-Fluc-tk was proved by gene-sequencing test.Human MCF-7 breast cancer cells showed a high ratio of firefly luciferase/renilla luciferase (0.64±0.10,n =4).A 520 bp band of product existed,which matched with the predicted size using RNA from cells transfected with Rib53-Fluc-tk in MCF-7.Signals were detected by bioluminescence in human embryonic kidney 293T cells co-transfected with Rib53-Fluc-tk and pCDNA3.1-CEA.The labelling rate of 131I-FIAU was (64.02±4.79)％ (n =3).The radiochemical purity was (95.96± 1.07)％ (n=3),and the stability of the radiocompound remained high in human serum at least for 24 h.The uptake of 131I-FIAU in 293T cells transfected with Rib53-Fluc-tk was (0.31±0.01)％ (n=4),while it increased with the incubation time in 293T cells co-transfected with pCDNA3.1-CEA and Rib53-Fluc-tk and reached (1.40±0.06)％ at 4.5 h (F=1 007.29,t=136.34,both P＜0.01).Conelusions A novel and specific reporter gene in the cellular level was established.Taking advantage of trans-splicing reaction of the ribozyme,it could improve the specificity of the reporter gene imaging.
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OBJECTIVE: With the growing interests of bacteria as a targeting vector for cancer treatment, diverse genetically engineered Salmonella has been reported to be capable of targeting primary or metastatic tumor regions after intravenous injection into mouse tumor models. The purpose of this study was to investigate the capability of the genetically engineered Salmonella typhimurium (S. typhimurium) to access the glioma xenograft, which was monitored in mouse brain tumor models using optical bioluminescence imaging technique. METHODS: U87 malignant glioma cells (U87-MG) stably transfected with firefly luciferase (Fluc) were implanted into BALB/cAnN nude mice by stereotactic injection into the striatum. After tumor formation, attenuated S. typhimurium expressing bacterial luciferase (Lux) was injected into the tail vein. Bioluminescence signals from transfected cells or bacteria were monitored using a cooled charge-coupled device camera to identify the tumor location or to trace the bacterial migration. Immunofluorescence staining was also performed in frozen sections of mouse glioma xenograft. RESULTS: The injected S. typhimurium exclusively localized in the glioma xenograft region of U87-MG-bearing mouse. Immunofluorescence staining also demonstrated the accumulation of S. typhimurium in the brain tumors. CONCLUSION: The present study demonstrated that S. typhimurium can target glioma xenograft, and may provide a potentially therapeutic probe for glioma.
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Animals , Mice , Bacteria , Brain Neoplasms , Fireflies , Fluorescent Antibody Technique , Frozen Sections , Glioma , Heterografts , Injections, Intravenous , Luciferases , Mice, Nude , Salmonella , Salmonella typhimurium , VeinsABSTRACT
Background Our previous study demonstrated that hyperglycemia aggravate the choroidal neovascularization (CNV) by promoting the chemotaxis process of bone marrow-derived cells (BMCs).Bioluminescence imaging (BLI) can dynamically monitor CNV in vivo.However,how diabetes mellitus (DM)participate in CNV is still in research.Objective This study was to dynamically observe the influence of BMCs to CNV under hyperglycaemia by using BLI combined with histopathology.Methods BMCs from luciferase-green fluorescent protein (Fluc-GFP) double transgenic mice were injected to adult wild type C57BL/6J mice (nine mice per group) via caudal vein to create the chimera models with a chimerism degree higher than 85％,and the chimeric mice were randomized into the control group and DM group based on randomized number table.Streptozotocin [60 mg/(kg · d)] was intraperitoneally injected daily for 5 days to establish the DM models in the chimeric mice of the DM group.CNV was induced in the chimeric mice of both control group and DM group with 532 nm laser photocoagulation.BLI signal of BMCsFluc+GFP+ was in vivo examined by IVIS Kinetics system 1,3,5,7,14,21 and 28 days after CNV modeling.At the seventh day after laser,part of mice were sacrificed,and choroidal and retinal sections were prepared for histopathological examination.The length and thickness of CNV were compared between the control group and DM group.The use and care of experimental followed Statement of ARVO.Results The chimerism degree of the chimeric mice was (88.85 ± 2.46) ％ 28 days after BMCs transplantation,and the blood glucose concentration in the DM group was (17.88±0.86)mmol/L.Histopathological examination revealed that CNV broke through the Bruch membrane toward subretinas.The length of the CNV was (338.67±33.17) μm in the DM group and (180.33±24.68)μm in the control group,showing a significant difference between the two groups (t =8.943,P＜0.05).However,no significant difference was seen in the CNV thickness between the two groups (t =1.790,P＞0.05).Light signals appeared 1 day and reach strongest 7 days after CNV modeling in both groups.The Light signals were stronger in the DM group than those in the control group on 5,7,14 and 21 days after CNV modeling (t =3.411,5.594,5.067,2.663,all at P＜0.05).Conclusions Hyperglycemia can promote more BMCs to participate in the pathogenesis and aggravation of CNV.The behavior of BMCs in CNV can be evaluated using BLI in vivo.
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Objective:Breast cancer metastasis is a major cause of death. Lymphatic metastasis is one of the two main metastatic ways that is crucial to the metastasis process of breast cancer. To treat breast cancer metastasis, we prepared micelle-based drug carrier for lymphatic delivery. Methods:We used in vivo bioluminescence imaging for real-time dynamic monitoring of the inhibitory effect of polyethylene glycol phospholipid micelle encapsulating vinorelbine on breast cancer metastasis. Results: Compared with the free vinorelbine, vinorelbine-encapsulated micelles (NanoVin) showed a significantly enhanced anti-tumor activity both in primary and met-astatic tumors. Conclusion:Intravenous administration of NanoVin markedly prevented the metastasis of tumor cells through both he-matogenous and lymphatic systems. This study provides a new approach for treatment of metastatic tumors. Bioluminescence imaging is a powerful tool to dynamically monitor tumor metastasis and clinical therapeutic effect of anticancer drugs.
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[Objective]To investigate the anti-proliferative effects of CEP on HCT116 cells and in mouse xenograft model. [Methods]The in vivo anti-cancer activity of CEP was determined with Xenogen bioluminescence imaging in a xenograft tumor model. The cel-based multiple signaling pathway reporter assays were carried out to determine the effects of CEP on these pathways. [Results] CEP inhibited growth of human cancer cells, the IC 50 was 0.8~11.5 μM. CEP induced cellcycle arrest in S and G2/M phase. CEP also inhibited xenograft tumor growth in athymic nude mice bearing HCT116 cells. The xenograft tumor size was significantly reduced upon the treatment with CEP(10 or 20 mg·kg-1 body weight) for up to 3 weeks. Pathway-spe-cific reporter assays indicated that CEP effectively suppressed the NF-κB and MAPK/ERK signaling pathways. [Conclusions] Our results suggest that the anticancer activity of CEP in colon cancer cells may be mediated through targeting NF-κB and MAPK/ERK signaling pathways.
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Objective To construct adenovirus vector containing firefly luciferase reporter gene (AdLuc) and infect bone marrow mesenchymal stem cells (BMSC),then to take bioluminescence imaging in vitro and in vivo for identification.Methods The luciferase gene was amplified with PCR from psiCHECK-2 plasmid and cloned into the adenoviral shuttle vector (pShuttle-CMV).It was confirmed by Nhe Ⅰ/Xba Ⅰ digestion and sequencing.PShuttle-CMV-Luc and backbone vector (pAdeno) were homologous recombined.Then the recombinant plasmid was packaged in HEK293 cells and the virus titer was detected.The BMSC were infected by the recombinant adenovirus.The bioluminescence imaging in vitro was performed to determine the best multiplicity of infection (MOI),and the relationship between bioluminescence intensity and MOI was analyzed by curve fitting regression analysis.Viability was evaluated via Trypan blue staining.The transfected BMSC (l× 106) were implanted into the muscles of forelimb of SD rats,and then tracked by bioluminescence imaging in vivo.Cell viability was compared using two-way repeated measures analysis of variance between groups.Results Enzyme digestion and sequence analysis indicated that Ad-Luc was successfully constructed.The virus titer was 1 × 1010 plaque forming unit (PFU)/ml.The bioluminescence detection in vitro showed that Ad-Luc could infect BMSC high efficiently to express luciferase and the best MOI was 50.The bioluminescence intensity enhanced with increase of MOI (R2 =0.98).No statistically significant difference was found in cell viability between transfected and untransfected BMSC at 1,3,5,7 d.The cell survival rates were (92.5±2.3)％ vs (94.1±1.8)％,(91.4±0.9)％ vs (92.7±2.0)％,(92.1±1.6)％ vs (93.3± 2.4) ％,(91.9 ± 1.5) ％ vs (93.0 ± 3.1) ％,respectively (F =4.38,P ＞ 0.05).The bioluminescence imaging in vivo showed that BMSC survived 1,3,7 d after implantation.However,bioluminescence signal decreased gradually over time.Conclusion It is feasible to apply the optical reporter gene imaging for tracing transplanted stem cells in vitro and in vivo due to the effective transformation of luciferase reporter gene into BMSC by adenovirus vector.
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Objective To establish cell strains stably transfected with Luciferase gene (Luc2), which was mediated by retrovirus, and explore the relationship between the number of Luc2-positive cells and light flux from bioluminescence imaging system by experiments in vitro and in vivo. Methods We co-transfected pMX-Luc2 plasmid and pMD.G plasmid into 293T gag-pol cells to get retrovirus expressing Luc2 gene. Stable Luc2 positive cell lines were generated and screened by transduction of Retro-Luc2 in mouse colon cancer cell line CT26, human non-small cell lung cancer cell line NCI-H446, human colon cancer cell line HT-29, human ovarian carcinoma cell line SKOV3 and human hepatocellular carcinoma cell line SMMC-7721, all of them were identified by bioluminescence imaging system. Different numbers of SKOV3-Luc2 cells ranging from 10 to 10000 were plated onto culture dishes. Two xenograft models of ovarian cancer were reproduced by subcutaneous injection of 200μl SKOV3-Luc2 cell suspension with different concentrations (1×107, 5×106, 2.5×106, 1×106, 5×105, 2.5×105, 1×105 and 5×104/ml) into 16 sites on the back of 4 nude mice, or intravenous injection of 1×106 or 3 ×106 SKOV3-Luc2 cells into the tail vein. Light flux value of SKOV3-Luc2 cells in dishes and in mice was measured by bioluminescence imaging system. Results Retro-Luc2 was constructed successfully and expressed Luc2 stably in transduced CT26, NCI-H446, HT-29, SKOV3 and SMMC-7721 cell lines. Light flux was correlated in a linear manner with the number of Luc2-positive cells in dishes and in mice (R2=0.944, β=0.972; R2=0.991, β=0.996; R2=0.351, β=0.628; P < 0.01). Conclusion Luc2-positive cell lines could be established rapidly and accurately by infecting tumor cells with retrovirus expressing Luc2. The number of Luc2 positive cells is significantly related in a linear manner to light flux from bioluminescence imaging system in vitro and in vivo.
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Objective To study the in vivo expression and biodistribution of Ad5-Fluc (Adenovirus carrying firefly luciferase genes) in mice.Methods The recombinant Ad5-Fluc virus was constructed and infected to BALB/c or nude mice through three different routes.The protein expression level,tissue distribution and the characteristics of infection were analyzed by in vivo bioluminescence imaging technology.Results Compared to other two routes,the BALB/c mice infected through muscular route had the longest expression cycle (over 60 days) and the highest expression level,while the virus was transferred into the liver and spleen after infection.The nude mice had a significantly extended expression cycle than BALB/c mice.Moreover,the characteristic of liver tropism was eliminated after Ad5 F35 infection in mice,while maintained similar expression efficiency.Conclusion Due to the highest expression efficiency,the muscular route would be the optimal route for Ad5 vector based vaccination.In addition,Ad5F35 virus could become an ideal alternative vaccine vector for eliminating the liver tropism.