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Objective:To investigate the effects of rapamycin on the autophagy activation of M2 macrophages and the radiosensitivity in colorectal cancer xenograft.Methods:THP-1 cells were induced into Type-Ⅱ macrophages with PMA and/or IL-4. Rapamycin and Bafilomycin A1 were uesd to activate and suppress autophagy of M2 macrophage, respectively. Colorectal cancer LoVo cells were inoculated on BALB/c-nu/nu nude mice. After the xenograft tumor size approached to 10 mm in diameter, the nude mice were divided into the following groups randomly: M2 macrophage autophagy inactive group and active group, autophagy downregulation of the activated group, and nontreatment control group. The tumors in mice were irradiated with 8 Gy X-rays in two fractions, and the radiosensitivity of colorectal cancer xenograft in each group was analyzed.Results:The expression levels of M2 macrophage markers Arg-1 and CCL-22 were significantly higher than those in M0 macrophage. The tumor weight, volume [(1.93±0.05)g, (2.14±0.06)cm 3] and micro-vessel density (36.37±1.04) in M2 autophagy inactive group were higher than those in control group [(1.35±0.05)g, (1.77±0.02)cm 3, 25.69±1.34] ( t=20.07, 14.56, 10.92, P < 0.05). After activation of M2 autophagy, the tumor weight, volume and micro-vessel density were significantly decreased to (0.89±0.03)g, (1.24±0.01)cm 3, and 13.60±1.52 ( t=44.37, 40.32, 21.43, P < 0.05). After down-regulation of M2 autophagy with bafilomycin A1, the tumor weight, volume and micro-vessel density were increased to (1.02±0.07)g, (1.37±0.02)cm 3, and 21.06±1.41 ( t=4.67, 13.79, 6.23, P < 0.05). Autophagy inaction suppressed the expression of Livin and Survivin in tumor ( t=2.64, 7.90, P < 0.05), and the activation of M2 autophagy further down-regulated the expression of Livin, Survivin ( t=5.43, 9.39, P < 0.05). The expression levels of Livin and Survivin were increased after the treatment with bafilomycin A1 ( t=2.80, 3.17, P<0.05). Conclusions:M2 macrophagy promoted the growth of colorectal cancer xenograft by inducing the formation of micro-vessels in the tumor, which is one of the mechanisms of tumor-associated macrophages participating in the radiotherapy resistance of colorectal cancer. Activation of M2 autophagy by rapamycin inhibited the ability of M2 macrophagy in promoting tumor growth, and induced apoptosis of colorectal cancer cells after radiotherapy by down-regulating the expression of anti-apoptotic genes Livin and Survivin, thus increased the radiosensitivity of colorectal cancer.
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After multidisciplinary treatment including radiotherapy,the median survival of patients with glioblastoma multiforme (GBM) remains approximately 1 year.The heterogeneity of the genome and proteome of glioblastoma stem cells (GSC) is the fundamental factor affecting the prognosis.Proteomics-based sensitization of key radioresistance proteins is expected to improve the prognosis of GBM patients.In this article,literature review was conducted from PubMed and other databases in the previous 10 years to systematically discuss the research progress on various commonly used protein quantitative techniques,tools for data processing analysis and the application in radioresistance and radiosensitization of GSCs.
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Objective To investigate whether silencing UCP2 can sensitize cervical cancer cell line Siha to radiation.Methods Siha cells were transfected with UCP2 siRNA and then irradiated by Xray.The radiosensitivity of Siha cells was verified by colony formation,CCK-8,apoptosis and immunofluorescence assays.The mitochondrial membrane potential and the production of reactive oxygen species (ROS) were detected to further explore the related mechanism.Results RT-PCR and Western blot assays showed that the expression of UCP2 in Siha cells was increased after irradiation and the UCP2 siRNA successfully silenced the expression of UCP in cells.According to the survival curves,the D0,Dq,N and SF2 were 1.54,1.31,2.31 Gy and 0.52 for siUCP2 group,2.50,3.64,4.30 Gy and 0.83 for blank control group,and 3.34,2.16,1.91 Gy and 0.69,for siNC group,respectively.The radiosensitivity enhancement ratio of silent group was 0.62 and 0.46,compared with blank control group and negative control group,respectively.The proliferative activity of cells in the silent group was lower than that in the control group (t =13.2,P＜0.05).Apoptosis levels in the silent group were significantly higher than those in the control group after irradiation (t=3.14,P＜0.05).At 4 h after irradiation,the ROS production in the silent group was significantly higher than that in the control group (t=19.10,P＜0.05).At 24 h after irradiation,the mitochondrial membrane potential of Siha cells in the silent group was significantly lower than that in the control group (t =4.18,P ＜ 0.05) Conclusions The radiosensitivity of Siha cells is enhanced after UCP2 silencing,and thus UCP2 may applicable as a new target for radiosensitization of cervical cancer cells.
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After multidisciplinary treatment including radiotherapy, the median survival of patients with glioblastoma multiforme (GBM) remains approximately 1 year. The heterogeneity of the genome and proteome of glioblastoma stem cells (GSC) is the fundamental factor affecting the prognosis. Proteomics-based sensitization of key radioresistance proteins is expected to improve the prognosis of GBM patients. In this article, literature review was conducted from PubMed and other databases in the previous 10 years to systematically discuss the research progress on various commonly used protein quantitative techniques, tools for data processing analysis and the application in radioresistance and radiosensitization of GSCs.
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Objective@#To investigate whether silencing UCP2 can sensitize cervical cancer cell line Siha to radiation.@*Methods@#Siha cells were transfected with UCP2 siRNA and then irradiated by X-ray. The radiosensitivity of Siha cells was verified by colony formation, CCK-8, apoptosis and immunofluorescence assays. The mitochondrial membrane potential and the production of reactive oxygen species (ROS) were detected to further explore the related mechanism.@*Results@#RT-PCR and Western blot assays showed that the expression of UCP2 in Siha cells was increased after irradiation and the UCP2 siRNA successfully silenced the expression of UCP in cells. According to the survival curves, the D0, Dq, N and SF2 were 1.54, 1.31, 2.31 Gy and 0.52 for siUCP2 group, 2.50, 3.64, 4.30 Gy and 0.83 for blank control group, and 3.34, 2.16, 1.91 Gy and 0.69, for siNC group, respectively. The radiosensitivity enhancement ratio of silent group was 0.62 and 0.46, compared with blank control group and negative control group, respectively. The proliferative activity of cells in the silent group was lower than that in the control group (t=13.2, P<0.05). Apoptosis levels in the silent group were significantly higher than those in the control group after irradiation(t=3.14, P<0.05). At 4 h after irradiation, the ROS production in the silent group was significantly higher than that in the control group (t=19.10, P<0.05). At 24 h after irradiation, the mitochondrial membrane potential of Siha cells in the silent group was significantly lower than that in the control group (t=4.18, P<0.05).@*Conclusions@#The radiosensitivity of Siha cells is enhanced after UCP2 silencing, and thus UCP2 may applicable as a new target for radiosensitization of cervical cancer cells.
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Objective: To explore the effects of up- and down-regulation of circadian clock gene Bmal1 on the growth and radiation sensitivity of nasopharyngeal carcinoma after CNE1 xenograft in nude mice. Methods: We produced four groups of cells using lentiviral transfection: cells overexpressing CNE1 (CNE1OE), negative control in which there was no overexpression of CNE1 (OENC), cells with short hairpin RNAi (CNE1sh3), and RNAi negative cells (CNE1shNC). We investigated the expression of Bmal1 protein in the aforementioned groups with Western blot. After subcutaneously injecting the four groups of cells in nude mice, the size of the xenograft was measured. Subsequently, the xenografts were irradiated with 15 Gy at 6 MeV, and variation in the xenograft volume was recorded. mRNA and protein expression levels of Bmal1, p53, and p21 in the xenograft were measured with RT-PCR and Western blot, respectively. Results: The CNE1OE group highly expressed Bmal1 protein whereas the CNE1sh3 group was silenced by RNAi as shown with the Western blot, indicating successful transfection. The xenograft in the nude mice developed well. The CNE1OE xenograft volume was lower than that of the CNE1OENC xenograft, whereas the CNE1sh3 xenograft was larger than the CNE1shNC xenograft (P<0.05). CNE1OE, CNE1OENC, and CNE1shNC xenograft volumes shrank after being irradiated (t=4.32, 5.38, 5.16, respectively; P<0.05) and the effect was the highest in the CNE1OE group. However, there was almost no variation in xenograft volume in the CNE1sh3 group. The relative amounts of mRNA and protein of Bmal1, P53, and P21 were higher in the CNE1OE group than in the CNE1OENC group,while they were lower in the CNE1sh3 group compared to the CNE1shNC group (P<0.05). Conclusions: Overexpression of Bmal1 inhibited the growth of the CNE1 xenograft in nude mice and enhanced its radiation sensitivity whereas silencing the Bmal1 gene by RNAi promoted the growth of the xenograft and led to radiation resistance. We believe that Bmal1 overexpression leads to P53 and P21 overexpression, thereby inhibiting the growth of the xenograft.
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Objective To disclose whether the down-regulation of Musashi1 gene can sensitize human colon carcinoma cell line HCT116 to radiation. Methods Lentviral vectors were used to knockdown the expression of Musashi1 gene in HCT116 cell line ( HCT116-Musashi1 ) and its negative control ( NC) . Cell survival was measured by the colony formation assay, cell apoptosis and cell cycle distribution were measured by a flow cytometry. Results HCT116-Musashi1 silence and its negative control cells were established successfully. The result of cell survival assay showed that D0 , Dq , N, SF2 were 1.55, 0.88, 1.76 Gy and 0.43 for the Musashil silence group, 2.17, 1.51, 2.01 Gy and 0.64 for control cells, and 1.99, 1.45, 2.07 Gy and 0.62 for siRN NC, respectively. The radiosensitivity of Musashi1 silence group was significantly higher than that of control and siRNA NC, and SER was 1.40 and 1.28 respectively. After 8 Gy irradiation, the apoptosis rate of silence group was always higher than other two groups at 24, 48, and 72 h after irradiation(F =65.16, P <0.05), but there was no statistically significant difference between control and NC (P>0.05). After 12 Gy irradiation, the percentage of cells in G2/M phase decreased significantly in the silence group compared with control group and NC group( F=65. 398,P<0. 05). Conclusions Knockdown of Musashi1 in HCT116 cells increases the radiosensitivity through promoting cell apoptosis and reversing G2/M arrest, indicating that Musashi1 may be a new target of radiotherapy.
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Objective To investigate the effect of evodiamine on the proliferation and sensitivity of endometrial cancer cells to irradiation.Methods After administration of evodiamine,cell proliferations of human endometrial carcinoma cell lines of Ishikawa,HEC-1A,AN3CA were detected by MTT and the half maximal inhibitory concentration (IC50) of drug was calculated.The cell lines most sensitive to drug were screened for further experiment and administered with evodiamine (IC50) and 8 Gy irradiation.Then,cell apoptosis was detected by flow cytometry,the levels of Cleaved Caspase-3,p38 and p-p38 were measured by Western blot,and the level of intracellular ROS was detected by a ROS kit.Cell clone survival was also detected to evaluate cell radiosensitivity.Results 1,2,4,6 and 8 μmol/L evodiamine could inhibit the proliferation of the cell line of Ishikawa,HEC-1A,and AN3CA with IC50 of(8.32 ± 0.95),(3.98 ± 0.84) and (4.78 ± 0.64) μmol/L,respectively.Compared with radiation alone,after radiation in combination with 4 μmol/L evodiamine,the apoptosis rate of HEC-1A cells was increased from (45.54 ±4.25)％ to (65.87 ±2.93)％ (t =11.010,P ＜0.05) and cell viability decreased from (41.84±4.18)％ to (33.27 ± 3.52)％ (t =7.484,P ＜0.05),and the levels of ROS,Cleaved Caspase-3 and p-p38 were also enhanced.In addition,the sensitivity ratio of evodiamine for HEC-1A cells was calculated to be 1.628.Conclusions Evodiamine could inhibit the proliferation,promote apoptosis and enhance the radiosensitivity of endometrial carcinoma cells,in which the intracellular ROS and p38 signaling pathway may be involved.
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Objective To observe the effect of PIF1 knockdown on cell growth and cell cycle arrest induced by ionizing radiation.Methods HeLa cell lines that consistently down-regulated PIF1 were prepared by the lentivirus granules interfering technology and confirmed by real-time PCR and Western blotting.The effect of down-regulation of PIF1 on cell growth and cell cycle arrest induced by ionizing radiation was evaluated by cell counting and flow cytometry.Results HeLa cell lines consistently down-regulating PIF1 were established.The growth of HeLa that down-regulated PIF1 was inhibited greatly after 4 Gy of γ-ray irradiation.There was little cell proliferation until the 5th day post 4 Gy γ-ray.Moreover, the S phase block and G2/M phase block of PIF1 knock-downed cell lines were significantly delayed after 8 Gy γ-ray irradiation.Conclusion Knockdown of PIF1 can significantly enhance the radiation sensitivity and delayes the S phase block and G 2 /M phase block induced by ionizing radiation.
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Objective:To explore the effects of radiation on miRNA-21 expression and the biology of human salivary gland adenoid cystic carcinoma cell lines(SACC-83,SACC-LM).Methods:In vitro cultured SACC-83 and SACC-LM cells were radiated by Varian 23 EX with the dose of 0(control),2,6 and 10 Gy respectively.Cell proliferation,apoptosis and miRNA-21 expression were observed by CCK-8 assay,flow cytometry and qRT-PCR methods respectively.Results:48 h after radiation the proliferation ability of SACC-LM cells decreased with the increasing dose of radiation(F =1 321.646,P =0.000),so did the miRNA-21 expression (F =177.964,P =0.011).However,the early apoptosis rate (F =354.484,P =0.039),the later apoptosis rate (F =254.278,P =0.042) and heteroploid ratio(F =1 562.991,P =0.001) increased with the increasing dose of radiation.In SACC-83 cell line 48 h after 6 Gy radiation the cell proliferation(F =1 537.214,P =0.013) and the miRNA-21 expression(F =134.868,P =0.017) were lower than that of other radiation doses.Moreover,the early apoptosis rate (F =88.579,P =0.006),the late apoptosis rate (F =1 391.345,P =0.033),heteroploid ratio(F =250.461,P =0.004) were higher than that of other radiation doses.Conclusion:The miRNA-21 expression in SACC-LM and SACC-83 cell lines is conversely associated with the radiation sensitivity.
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Objective The purpose of this study is to investigate the effect of miR-449a on pancreatic cancer cells and the molecular mechanism. Methods The expression levels of miR-449a in pancreatic cancer cells treated or untreated with radiation was detected by qRT-PCR.High expression of miR-449a was achieved by transfecting miR-449a mimics into SW1990 cells. The cell growth,apoptosis and colony formation ability was assessed by MTT assay,flow cytometry and colony formation assay,respectively. The relationship of miR-449a and Cyclin D1 was determined by the TargetScan and dual luciferase reporter. Immunohistochemistry was used to examine protein levels of Cyclin D1 in pancreatic cancer and normal pancreas tissues. Si-Cyclin D1 was used to detecte the effect of Cyclin D1 on radiosensitivity of pancreatic cancer cells. Results The expression levels of miR-449a in pancreatic cancer cells with radiation treatment were decreased significantly. Mir-449a mimics increased the cell proliferation rates and apoptosis rates obviously,and decreased the colony formation ability in SW1990 cells treated with radiation. Results from the TargetScan and dual luciferase reporter showed that Cyclin D1 was the target of miR-449a. The positive staining rates of Cyclin D1 in pancreatic cancer tissue(85.7%,30/35)was higher than those in normal pancreas tissue(20%,2/10).Knockdown of Cyclin D1 enhanced the radiosensitivity of pancreatic cancer cells.Conclusion MiR-449a enhances the radiosensitivity of pancreatic cancer cells by targeting Cyclin D1.
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OBJECTIVE@#To identify the influence on radiosensitivity of lung glandular cancer cells when excisions repair cross-complementing group1 (ERCC1) gene was silenced by targeted siRNA.@*METHODS@#siRNA which targeting to ERCC1 and control siRNA was designed and synthesized. The human lung glandular cancer SPC-A-1 cells was transfected. A total of 56 nude mice were divided into two groups, and two kinds of SPC-A-1 cells were transplanted to armpit of right forelimb, to establish the nude mice subcutaneous xenotransplanted tumor model of human lung glandular cancer cells. After the tumor was developed, the nude mice were randomly divided into four groups and accepted different doses of X-Ray radiation, then the change of tumor volume, survival time of mice in every group were recorded and the average lifetime was calculated. Twenty-one days later of X-ray experiment, two mice were taken and killed in each group and the tumors organizations were stripped. The cell apoptosis rate and cell cycle distributions were obtained by FCM (flow cytometry).@*RESULTS@#The volume of tumor which ERCC1 gene was silenced was less than single irradiation group after X-ray irradiation, and the growth speed was slower and the lifetime of mice was lengthened as well (P < 0.05). The cells apoptosis rate and the rate of G2/M cells which ERCC1 gene was silenced were higher than the same dose control group and the rate of G1 cells were lower, which indicated that the cells could be stopped at G2/M point, the cell proliferation was inhibited, the cell apoptosis was promoted and the radiation sensitivity was improved after the ERCC1 was silenced.@*CONCLUSIONS@#The radiation sensitivity of lung glandular tumor could be improved after the ERCC1 gene was silenced by siRNA.
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Objective To investigate the low-dose hyper-radiosensitivity (HRS)/induced radioresistance (IRR) in A549 cells synchronized at G2 phase and the role of ATM kinase in the process.Methods Human lung adenocarcinoma cell line A549 was synchronized at G2 phase by aphidicolin.The ATM-specific activator and inhibitor,chloroquine and KU55933,were used to regulate the activity of ATM.The colony formation assay was used to evaluate cell survival.Flow cytometry was used to determine the cell cycle of radiation-exposed A549 cells synchronized at G2 phase.Immunofluorescence was used to observe the dynamics of γ-H2AX fluorescence and evaluate the efficiency of DNA repair in A549 cells synchronized at G2 phase.Western blot was used to detect the expression of phosphorylated ATM (Ser1981) and ATM.Results A549 cells synchronized at G2 phase had substantially enhanced HRS than non-synchronized cells.The dose-induced transition from HRS to 1RR was in accordance with the dose-response pattern of early G2/M checkpoint.However,with the same threshold dose,the activation of early checkpoint occurred earlier and lasted longer than normal.The activation of ATM kinase inhibited HRS and enhanced DNA repair,while the inhibition of ATM kinase enhanced HRS and hindered DNA repair.Conclusions ATM kinase-mediated early G2+M checkpoint is a molecular switch for HRS in synchronized A549 cells.Low-dose irradiation with G2-phase synchronization and ATM inhibitor can enhance the low-dose radiosensitivity.
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Cumulative evidence demonstrated that the chromatin modification plays important roles in the processes of DNA replication,transcription,repair and recombination.Both of the generation of DNA lesions and the activation of DNA damage response (DDR) to ionizing radiation could be affected by the chromatin modifications.This paper reviewed the recent research progresses in the chromatin structure modifications and its role in DDR,especially the influence of characteristic chromatin structure and histone modification on the radiation sensitivity of tumor cells.
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Objective To identify the influence on radiosensitivity of lung glandular cancer cells when excisions repair cross-complementing group1 (ERCC1) gene was silenced by targeted siRNA. Methods siRNA which targeting to ERCC1 and control siRNA was designed and synthesized. The human lung glandular cancer SPC-A-1 cells was transfected. A total of 56 nude mice were divided into two groups, and two kinds of SPC-A-1 cells were transplanted to armpit of right forelimb, to establish the nude mice subcutaneous xenotransplanted tumor model of human lung glandular cancer cells. After the tumor was developed, the nude mice were randomly divided into four groups and accepted different doses of X-Ray radiation, then the change of tumor volume, survival time of mice in every group were recorded and the average lifetime was calculated. Twenty-one days later of X-ray experiment, two mice were taken and killed in each group and the tumors organizations were stripped. The cell apoptosis rate and cell cycle distributions were obtained by FCM (flow cytometry). Results The volume of tumor which ERCC1 gene was silenced was less than single irradiation group after X-ray irradiation, and the growth speed was slower and the lifetime of mice was lengthened as well (P < 0.05). The cells apoptosis rate and the rate of G
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Objective To investigate the role of a small RNA interference against VEGF in radiation sensitivity in melanoma .Methods A375 human melanoma cell lines were transplanted into nude mice ,which with malignant melanoma were randomly divided into control group , VEGF negative plasmid group and VEGF positive plasmid group, followed by 4Gy irradiation twice a week for 2 weeks.The volume of tumor was calculated twice a week, the area of tumor necrosis was assayed by HE,the expression of VEGF in tumor was determined by Western-blot and Immunohistochemical. ResuIts The expression of VEGF in VEGF positive plasmid group decreased significantly (P<0.05), VEGF positive group had more tissue necrosis, tumor growth was significantly inhibited (P<0.05).ConcIusion siRNA-VEGF in tumor injection liposome encapsulated in malignant melanoma has a role in the radiation sensitization, which provides an experimental basis for the clinical development of targeted therapy combined with radiotherapy for the treatment of VEGF gene.
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Objective:To investigate the inhibitory effect of dihydroartemisinin on non-small cell lung cancer H1299 cells.Methods:Through the CCK-8 method for determining the IC 10 of dihydroartemisinin ,choose low dose IC 10 as the experimental concentration,CCK-8 to observe artemisinin in low doses of H1299 cell proliferation, cycle and the influence of radiation sensitivity.Results:IC10 of dihydroartemisinin was 14.87 μmol/L,dihydroartemisinin could inhibit proliferation of H 1299 cells,slow down the cell cycle , and increased the radiation sensitivity.Conclusion: Dihydroartemisinin can inhibit cell proliferation , cell cycle arrest in S phase ,increase the radiation sensitivity.
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Objective:To investigate the expression level of pyruvate kinase M2 (PKM2) in tissues of non-small cell lung cancer (NSCLC) patients and the correlation between PKM2 expression level and radiation sensitivity. Methods:A total of 45 NSCLC pa-tients were chosen and treated with radiotherapy for two months after surgery. The patients were classified into four groups based on the curative effect. The mRNA expression levels of PKM2 in tumor and the homologous paraneoplastic tissues of NSCLC patients were de-tected prior to radiotherapy using real time-polymerase chain reaction (RT-PCR), and the protein expressions of PKM2 in the tumor and paraneoplastic tissues of NSCLC patients were detected with Western blot analysis and immunohistochemical method. The mRNA and protein expression levels of PKM2 in the tumor tissues of different groups were detected with RT-PCR and Western blot assays. Re-sults:The effective rate of radiotherapy for 2 months is 44.8%in NSCLC patients. The expression level of PKM2 is significantly high-er in tumor tissues than in homologous paraneoplastic tissues of NSCLC patients and is negatively correlated with the curative effect of radiotherapy. Conclusion:The expression level of PKM2 is significantly higher in tumor tissues than in the paraneoplastic tissues of NSCLC patients. Patients with lower PKM2 expression level are more sensitive to radiotherapy.
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Objective To research the relationship between miR-21 and radiation sensitivity of cervical cancer HeLa cells,and to elucidate the possible action mechanism of miR-21 in apoptosis and autophagy of cells.Methods The HeLa cells were divided into mock groups (transfected with miR-21 NC,mimics,inhibitor NC or inhibitor)and 4 Gy irradiation groups (transfected with miR-2 1 NC, mimics,inhibitor NC or inhibitor with irradiation). The miR-2 1 expression was detected by real-time PCR;colony-forming assay was used to detect the changes of radiation sensitivity;the apoptosis and autophagy were analyzed by FACS assay;the target gene of miR-2 1 was predicted by bioinformatics methods;Dual-luciferase Reporter Assay was used to demonstrate the binding of miR-2 1 and targets;the expression of beclin1 protein was measured by Western blotting method. Results After 4 Gy radiation,compared with mock group,the expression of miR-21 was increased remarkably (P0.05).Compared with miR-21 NC+4 Gy group,the apoptotic rate of HeLa cells in miR-21 mimics+4 Gy group was increased (P<0.05).After transfection with miR-21 inhibitor,compared with miR-21 inhibitor NC group,the apoptotic rate of HeLa cells in duced by radiation was decreased (P<0.05 ). Compared with miR-21 NC group, the autophagy rate was increased after transfection with miR-21 mimics (P<0.05).After transfection with miR-21 mimics and radiation, the expression level of beclin1 protein was increased (P<0.05 ) compared with miR-21 NC+4 Gy group. Conclusion Beclin1 is the target gene of miR-21 in HeLa cells. Overexpression of miR-21 can increase the radiation-induced apoptosis and autophagy,but has on influence in radiation sensitivity of HeLa cells.
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Objective To clarify the mechanism of immediate early response gene 5 (ler5)transcription induced by radiation. Methods Deletant construction, site-specific mutagenesis,electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) were used to forecast the promoter region,binding sites and transcription factors of Ier5 gene in HeLa cells.Results The promoter region of Ier5 gene might be in the region of Ier5 -8 deletant ( -408 - -238 bp).The Ier5 gene had two transcription factors of GCF and NFI,and GCF had two binding sites located in the region of - 388 - - 382 bp and - 274 - - 270 bp of Ier5 promoter.The binding site of NFI was located in - 362 --357 bp of Ier5 promoter. GCF could inhibit the expression of Ier5 gene and this inhibition was diminished when the radiation dose increased. In contrast, NFI increased the expression of Ier5.Conclusions The most possible region of Ier5 promoter is from -408 to - 238 bp which has two binding sites for the radiosensitivity transcription factors of GCF and NFI that could negatively and positively regulate the expression of Ier5 respectively.