Objective: To investigate the co-expression of drug resistance- and apoptosis-related genes of cisplatin (CDDP)-selected lung adenocarcinoma cell line A 549 DDP for compared to the parental cell line A549, and reverse...Objective: To investigate the co-expression of drug resistance- and apoptosis-related genes of cisplatin (CDDP)-selected lung adenocarcinoma cell line A 549 DDP for compared to the parental cell line A549, and reverse of drug resistance by antisense s-oligodeoxynucleotides (S-ODNs) of differentially expressed genes. Methods: Sense and antisense S-ODN were transferred into A 549 DDP cells by lipofectin. The expression of drug resistance and apoptosis related genes was examined by RT-PCR, immunocytochemistry and flow cytometry, respectively. Apoptostic cells were identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT)-mediated biotin dUTP nick end-labeling(TUNEL). Drug resistance of tumor cells was detected by a cell viability (MTT) assay. Results: The expression of bcl-2 was positive and that of multidrug resistance-associated protein (MRP) at mRNA and protein level was increased in A 549 DDP compared to A549 cells. MDR1, c-myc and topoisomeras II (TOPO II) were similarly co-expressed in two cell lines. Both cell lines were negative for c-erbB-2 expression. In A 549 DDP cells, the expression of bcl-2 and MRP was significantly inhibited by their respective antisense S-ODNs. Antisense S-ODNs could also decrease significantly drug resistance of A 549 DDP cells to CDDP by promoting cell apoptosis. Conclusion: Both intrinsic and acquired drug resistance were involved in co-expression of multiple MDR-related genes in lung adenocarcinoma. Cooperation of bcl-2 and MRP genes appeared to play an important action to confer the resistance of A 549 DDP cells to CDDP. Their antisense S-ODNs are responsible for the decrease of drug resistance of this cell line by promoting apoptosis.展开更多
The low dose hyper-radiosensitivity （HRS） in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the pos...The low dose hyper-radiosensitivity （HRS） in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with ^60Co y-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981 Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at 〉0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation （P〉0.05）. After exposure to 0.3, 0.4 and 0.5 Gy radiation, G2/M phase arrest occurred 6 and 12 h after radiation （P〈0.05）, and the ratio of G2/M phase cells was decreased 24 h after radiation （P〈0.05）. It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.展开更多
Objective: To synthesize bio-inspired gold nanoparticles(AuNPs) using the leaf extract of Justicia adhatoda and evaluate the anti-cancer activity on human lung cancer cell line(A549).Methods: Synthesis of AuNPs was do...Objective: To synthesize bio-inspired gold nanoparticles(AuNPs) using the leaf extract of Justicia adhatoda and evaluate the anti-cancer activity on human lung cancer cell line(A549).Methods: Synthesis of AuNPs was done using an aqueous leaf extract of Justicia adhatoda as a green route. The bio-synthesized AuNPs were confirmed and characterized by using various spectral studies such as UV-Vis spectrum, Scanning Electron Microscope with EDAX, Transmission Electron Microscope, Fourier Transmission Infrared Spectroscope analysis and Surface Enhanced Raman Spectroscopy. The cell viability was determined by MTT reduction assay. In addition, cytomorphology and the nuclear morphological study of A549 cell line was observed under fluorescence microscope. Results: UV-Vis spectrum showed surface plasmon resonance peak at 547 nm, scanning electron microscope and transmission electron microscope studies showed the monodispersed spherical shape and its average size in the range of 40.1 nm was noticed. Fourier Transmission Infrared Spectroscope analysis confirmed that the C=O group of amino acids of proteins had strong ability to bind with the surface of nanoparticle. Interestingly, our results also demonstrated inhibited proliferation of A549 cell line by MTT(IC50 value: 80 μg/mL). Cell morphology was observed and cell death was caused by apoptosis as revealed by propidium iodide staining. Conclusions: The current study proves the anticancer potential of bio-synthesized AuNPs. Thus, synthesized AuNPs can be used for the treatment of human lung cancer cell(A549) and it can be exploited for drug delivery in future.展开更多
OBJECTIVE： Deoxyelephantopin, a sesquiterpene lactone from Elephantopus scaber, showed inhibition of the growth of various tumor cells in vitro. In the present study, we investigated the cytotoxicity and apoptosis-in...OBJECTIVE： Deoxyelephantopin, a sesquiterpene lactone from Elephantopus scaber, showed inhibition of the growth of various tumor cells in vitro. In the present study, we investigated the cytotoxicity and apoptosis-inducing capacity of deoxyelephantopin on lung adenocarcinoma （A549） cells. METHODS： The cytotoxic effect of deoxyelephantopin on A549 cells and normal lymphocytes was evaluated using 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 50% inhibitory concentration （IC50） value was determined. The self-renewal and proliferating potential of A549 cells after treatment with deoxyelephantopin were examined by colony formation assay. Cellular morphology of deoxyelephantopin-treated cells was observed using phase- contrast microscopy. The induction of apoptosis was evaluated using acddine orange and ethidium bromide staining, Hoechst 33342 staining, terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end-labeling （TUNEL） assay, DNA fragmentation analysis and Annexin V-fluorescein isothiocyanate staining by flow cytometry. Activation of caspases was detected using fluorogenic substrate specific to caspases 2, 3, 8 and 9 and flow cytometric analysis. The total cellular DNA content and expression of cleaved poly （ADP-ribose） polymerase was also analyzed. RESULTS： Deoxyelephantopin exhibited cytotoxicity to A549 cells （IC50 = 12.287 μg/mL）, however, there was no toxicity towards normal human lymphocytes. Deoxyelephantopin suppressed the colony-forming ability of A549 cells in a dose-dependent manner. Acridine orange, ethidium bromide and Hoechst 33342 staining showed cell shrinkage, chromosomal condensation and nuclear fragmentation, indicating induction of apoptosis. Deoxyelephantopin increased apoptosis of A549 cells, as evidenced by more TUNEL-positive cells. DNA fragmentation and Annexin V staining revealed late-stage apoptotic cell population. Deoxyelephantopin inhibited A549 cell growth by cell cycle arrest at G2/M phase and induced apoptosis through both extrinsic and intrinsic pathways. CONCLUSION： These results suggest that deoxyelephantopin has great potential as a new chemotherapeutic agent to be developed further for the treatment of lung cancer.展开更多
Objective: Recombinant human Endostatin(rh-Endostatin, YH-16) can reverse cisplatin resistance in A549/DDP cells. However, the possible effect of rh-Endostatin in reversing DDP-resistance in A549/DDP cells and the mec...Objective: Recombinant human Endostatin(rh-Endostatin, YH-16) can reverse cisplatin resistance in A549/DDP cells. However, the possible effect of rh-Endostatin in reversing DDP-resistance in A549/DDP cells and the mechanism are needed to be investigated. Methods: Lung adenocarcinoma cell line A549 and its DDP-resistant cell line A549/DDP were treated with DDP and/or recombinant human Endostatin. Difference in drug resistance was analyzed between different regimens and between different cell lines after a 72 h-treatment in vitro. And below the non-cytotoxic concentration of rh-Endostatin, the possibility of rh-Endostatin in reversing DDP-resistance in A549/DDP was evaluated. The resistance protein which was detected in the study included P glycoprotein(P-gp) and topoisomerase II(Topo-II). Results: Rh-Endostatin below 400 μg/mL showed no cytotoxicity in either A549 or A549/DDP after 72 h-treatment with it. The inhibited concentration of 50%(IC50) observed for DDP was(0.79 ± 0.05) μg/mL in A549 and(13.2 ± 1.1) in A549/DDP respectively. IC50 was reduced to 2.57 ± 0.05 μg/mL in A549/DDP treated by rh-Endostatin below the non-cytotoxic concentrations in combination with DDP, with a reversal fold(RF) of 5.14 and a relative reversal rate of 85.6%. Apoptotic rates were 2.01%, 13.47% and 29.26% respectively for cells treated with rh-Endostain, DDP, and the combination. The rate of the A549/DDP control group was 0.99%. The expression level of P-gp or Topo-II was higher in A549/DDP cells than in A549 cells. Rh-Endostatin may partially reverse DDP-resistance in A549/DDP cells in vitro, with a probable mechanism related to lowering expression of P-gp and Topo-II. Conclusion: Rh-Endostatin of non-cytotoxic dose partially reversed cisplatin resistance in cisplatin-resistant human lung adenocarcinoma cell line A549/DDP. Rh-Endostatin reversed the resistance of A549/DDP cells to DDP, which may be related to decreased protein expression of P-gp and Topo-II in A549/DDP cells.展开更多
Objective: To clone multidrug resistance (MDR) related genes in lung adenocarcinoma cell lines. Methods: The differentially expressed cDNA fragments between A549 and A549 DDP cells were analyzed by mRNA differential d...Objective: To clone multidrug resistance (MDR) related genes in lung adenocarcinoma cell lines. Methods: The differentially expressed cDNA fragments between A549 and A549 DDP cells were analyzed by mRNA differential display PCR(DD RT-PCR). The fragments thus obtained were further analyzed by DNA sequencing and Northern blotting. Results: Three differentially expressed cDNA fragments were obtained and confirmed by Northern blot. Sequence analysis revealed that two of them were novel and one was 100% identical with ICE gene. Conclusion: Analyzing differentially expressed fragment between A549 and A549 DDP cells may be helpful for finding new MDR related genes. The drug resistance of A549 DDP cells may be related to the inhibition or down-regulation of ICE gene.展开更多
Objective： Even though radiotherapy plays a major role in the local treatment of non-small cell lung cancer （NSCLC）, little is known about the molecular effects of irradiation in this tumor. In the present study, w...Objective： Even though radiotherapy plays a major role in the local treatment of non-small cell lung cancer （NSCLC）, little is known about the molecular effects of irradiation in this tumor. In the present study, we examined two NSCLC cell lines for their endogenous production of TNF-α after irradiation. To investigate the radiation-induced TNF-α production in NSCLC cell lines. Methods： Two human NSCLC cell lines （A549： squamous; NCI-H596： adenosquamous） were investigated for their TNF-α mRNA （real-time RT-PCR） after exposure to different irradiation doses （2, 5, 10, 20, 30, 40 Gy） and time intervals （1, 3, 6, 12, 24, 48 or 72 h）. The TNF-α mRNA expression was quantified by real-time RT-PCR. The clonogenic survival was evaluated after irradiation with 2, 4, 6 and 8 Gy. Results： Non-irradiated NSCLC cells exhibited no or very low TNF-α expression. For the NCI-H596 cell line, TNF-α expression was significantly elevated 1～12 h （maximum 6h： 568fold increase relative to unirradiated cells） in a time-dependent manner. The radiation-induced increase could be observed after irradiation with 2 Gy reaching maximal at 40 Gy, with 83 times higher than normal controls. The clonogenic survival of these cell lines was nearly identical. Conclusion： NCI-H596 cells produce significant quantities of TNF-α following irradiation in a time- and dose-dependent manner. The pro-inflammatory cytokine TNF-α is a key mediator for the pathogenesis of radiation pneumonitis. Radiation-induced endogenous TNF-α expression in NSCLC cells may affect the normal lung adjacent to the tumor and may be associated with an adverse clinical outcome of the patient.展开更多
背景白藜芦醇不仅具有抗肿瘤作用,其还能增强多种化疗药物的化疗敏感性,但其对食管癌耐药细胞的顺铂敏感性的作用尚不清楚.目的探讨白藜芦醇逆转食管癌细胞Eca109/DDP的耐药效应并从铁死亡的角度分析其潜在的作用机制.方法采用MTT法确...背景白藜芦醇不仅具有抗肿瘤作用,其还能增强多种化疗药物的化疗敏感性,但其对食管癌耐药细胞的顺铂敏感性的作用尚不清楚.目的探讨白藜芦醇逆转食管癌细胞Eca109/DDP的耐药效应并从铁死亡的角度分析其潜在的作用机制.方法采用MTT法确定白藜芦醇和顺铂的最佳作用时间和浓度;检测细胞增殖、细胞内丙二醛(malondialdehyde,MDA)、谷胱甘肽(glutathione,GSH)、活性氧(reactive oxygen species,ROS)及铁离子的水平;Western blot检测铁死亡相关调控因子酰基辅酶A合成酶长链家族成员4(acyl coenzyme A synthetase long chain family member 4,ACSL4)、铁蛋白重链(ferritin heavy chain,FTH)、谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)和肿瘤蛋白53(tumor protein 53,P53)的蛋白表达情况.结果MTT检测结果显示,相较于单用顺铂,联用白藜芦醇对Eca109/DDP细胞的生长抑制作用较为显著(P<0.05).此外,白藜芦醇和顺铂联用可显著降低Eca109/DDP细胞克隆形成数(P<0.05),增加细胞内铁离子、MDA和ROS水平(P<0.05),降低GSH水平(P<0.05).铁死亡抑制剂(ferrostatin-1,Fer-1)和铁离子螯合剂(deferoxamine,DFO)可部分逆转白藜芦醇对细胞增殖的抑制作用(P<0.05).Western blot的结果显示相较于其他组,白藜芦醇和顺铂联用组的FTH和GPX4的蛋白表达显著降低(P<0.05),而ACSL4和P53的蛋白表达显著增加(P<0.05).结论白藜芦醇可通过铁死亡抑制Eca109/DDP细胞的增殖并逆转顺铂耐药.展开更多
目的:探讨叉头框转录因子M1(FoxM1)对人宫颈癌顺铂耐药株Hela/DDP增殖、侵袭、凋亡的影响及其机制。方法:将Hela/DDP细胞分为空白组(常规培养,不予任何处理)、正常对照(NC)组(转染空白干扰质粒)、低表达组和过表达组。低表达组转染siRNA...目的:探讨叉头框转录因子M1(FoxM1)对人宫颈癌顺铂耐药株Hela/DDP增殖、侵袭、凋亡的影响及其机制。方法:将Hela/DDP细胞分为空白组(常规培养,不予任何处理)、正常对照(NC)组(转染空白干扰质粒)、低表达组和过表达组。低表达组转染siRNA-FoxM1下调Hela/DDP细胞中FoxM1表达,过表达组转染pcDNA3.1-FoxM1上调Hela/DDP细胞中FoxM1表达。采用RT-qPCR法检测FoxM1 m RNA表达水平,CCK-8检测细胞活力,流式细胞仪检测细胞凋亡,Transwell小室检测细胞侵袭能力。结果:FoxM1 mRNA在Hela细胞中的表达水平低于Hela/DDP细胞(P<0.05)。空白组与NC组中FoxM1 mRNA、增殖率、凋亡率、侵袭细胞数及HSP70、S100A9蛋白表达水平比较,差异均无统计学意义(P>0.05)。与空白组比较,低表达组细胞活力和侵袭能力及FoxM1 mRNA、HSP70蛋白表达水平降低,凋亡率和S100A9蛋白表达水平升高(P<0.05),与空白组比较,过表达组细胞活力和侵袭能力及FoxM1 m RNA、HSP70蛋白表达水平升高,凋亡率和S100A9蛋白表达水平降低(P<0.05)。与低表达组比较,过表达组细胞活力和侵袭能力及FoxM1 mRNA、HSP70蛋白表达水平升高,凋亡率和S100A9蛋白表达水平降低(P<0.05)。结论:下调FoxM1表达可抑制HSP70表达,促进S100A9表达,调控宫颈癌细胞恶性行为,从而提高宫颈癌顺铂耐药细胞株对顺铂化疗的敏感性。展开更多
基金the Grant from Beijing Natural Science Foundation (No.7992005)and a Grantfrom Postdoctoral Foundation of National Committee of E
文摘Objective: To investigate the co-expression of drug resistance- and apoptosis-related genes of cisplatin (CDDP)-selected lung adenocarcinoma cell line A 549 DDP for compared to the parental cell line A549, and reverse of drug resistance by antisense s-oligodeoxynucleotides (S-ODNs) of differentially expressed genes. Methods: Sense and antisense S-ODN were transferred into A 549 DDP cells by lipofectin. The expression of drug resistance and apoptosis related genes was examined by RT-PCR, immunocytochemistry and flow cytometry, respectively. Apoptostic cells were identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT)-mediated biotin dUTP nick end-labeling(TUNEL). Drug resistance of tumor cells was detected by a cell viability (MTT) assay. Results: The expression of bcl-2 was positive and that of multidrug resistance-associated protein (MRP) at mRNA and protein level was increased in A 549 DDP compared to A549 cells. MDR1, c-myc and topoisomeras II (TOPO II) were similarly co-expressed in two cell lines. Both cell lines were negative for c-erbB-2 expression. In A 549 DDP cells, the expression of bcl-2 and MRP was significantly inhibited by their respective antisense S-ODNs. Antisense S-ODNs could also decrease significantly drug resistance of A 549 DDP cells to CDDP by promoting cell apoptosis. Conclusion: Both intrinsic and acquired drug resistance were involved in co-expression of multiple MDR-related genes in lung adenocarcinoma. Cooperation of bcl-2 and MRP genes appeared to play an important action to confer the resistance of A 549 DDP cells to CDDP. Their antisense S-ODNs are responsible for the decrease of drug resistance of this cell line by promoting apoptosis.
文摘The low dose hyper-radiosensitivity （HRS） in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with ^60Co y-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981 Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at 〉0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation （P〉0.05）. After exposure to 0.3, 0.4 and 0.5 Gy radiation, G2/M phase arrest occurred 6 and 12 h after radiation （P〈0.05）, and the ratio of G2/M phase cells was decreased 24 h after radiation （P〈0.05）. It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.
文摘Objective: To synthesize bio-inspired gold nanoparticles(AuNPs) using the leaf extract of Justicia adhatoda and evaluate the anti-cancer activity on human lung cancer cell line(A549).Methods: Synthesis of AuNPs was done using an aqueous leaf extract of Justicia adhatoda as a green route. The bio-synthesized AuNPs were confirmed and characterized by using various spectral studies such as UV-Vis spectrum, Scanning Electron Microscope with EDAX, Transmission Electron Microscope, Fourier Transmission Infrared Spectroscope analysis and Surface Enhanced Raman Spectroscopy. The cell viability was determined by MTT reduction assay. In addition, cytomorphology and the nuclear morphological study of A549 cell line was observed under fluorescence microscope. Results: UV-Vis spectrum showed surface plasmon resonance peak at 547 nm, scanning electron microscope and transmission electron microscope studies showed the monodispersed spherical shape and its average size in the range of 40.1 nm was noticed. Fourier Transmission Infrared Spectroscope analysis confirmed that the C=O group of amino acids of proteins had strong ability to bind with the surface of nanoparticle. Interestingly, our results also demonstrated inhibited proliferation of A549 cell line by MTT(IC50 value: 80 μg/mL). Cell morphology was observed and cell death was caused by apoptosis as revealed by propidium iodide staining. Conclusions: The current study proves the anticancer potential of bio-synthesized AuNPs. Thus, synthesized AuNPs can be used for the treatment of human lung cancer cell(A549) and it can be exploited for drug delivery in future.
基金Kerala State Council for Science Technology and Environment (KSCSTE) and University Grant Commission for financial support
文摘OBJECTIVE： Deoxyelephantopin, a sesquiterpene lactone from Elephantopus scaber, showed inhibition of the growth of various tumor cells in vitro. In the present study, we investigated the cytotoxicity and apoptosis-inducing capacity of deoxyelephantopin on lung adenocarcinoma （A549） cells. METHODS： The cytotoxic effect of deoxyelephantopin on A549 cells and normal lymphocytes was evaluated using 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 50% inhibitory concentration （IC50） value was determined. The self-renewal and proliferating potential of A549 cells after treatment with deoxyelephantopin were examined by colony formation assay. Cellular morphology of deoxyelephantopin-treated cells was observed using phase- contrast microscopy. The induction of apoptosis was evaluated using acddine orange and ethidium bromide staining, Hoechst 33342 staining, terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end-labeling （TUNEL） assay, DNA fragmentation analysis and Annexin V-fluorescein isothiocyanate staining by flow cytometry. Activation of caspases was detected using fluorogenic substrate specific to caspases 2, 3, 8 and 9 and flow cytometric analysis. The total cellular DNA content and expression of cleaved poly （ADP-ribose） polymerase was also analyzed. RESULTS： Deoxyelephantopin exhibited cytotoxicity to A549 cells （IC50 = 12.287 μg/mL）, however, there was no toxicity towards normal human lymphocytes. Deoxyelephantopin suppressed the colony-forming ability of A549 cells in a dose-dependent manner. Acridine orange, ethidium bromide and Hoechst 33342 staining showed cell shrinkage, chromosomal condensation and nuclear fragmentation, indicating induction of apoptosis. Deoxyelephantopin increased apoptosis of A549 cells, as evidenced by more TUNEL-positive cells. DNA fragmentation and Annexin V staining revealed late-stage apoptotic cell population. Deoxyelephantopin inhibited A549 cell growth by cell cycle arrest at G2/M phase and induced apoptosis through both extrinsic and intrinsic pathways. CONCLUSION： These results suggest that deoxyelephantopin has great potential as a new chemotherapeutic agent to be developed further for the treatment of lung cancer.
基金Supported by a grant from the Natural Science Foundation of Liaoning Province(No.201202043)
文摘Objective: Recombinant human Endostatin(rh-Endostatin, YH-16) can reverse cisplatin resistance in A549/DDP cells. However, the possible effect of rh-Endostatin in reversing DDP-resistance in A549/DDP cells and the mechanism are needed to be investigated. Methods: Lung adenocarcinoma cell line A549 and its DDP-resistant cell line A549/DDP were treated with DDP and/or recombinant human Endostatin. Difference in drug resistance was analyzed between different regimens and between different cell lines after a 72 h-treatment in vitro. And below the non-cytotoxic concentration of rh-Endostatin, the possibility of rh-Endostatin in reversing DDP-resistance in A549/DDP was evaluated. The resistance protein which was detected in the study included P glycoprotein(P-gp) and topoisomerase II(Topo-II). Results: Rh-Endostatin below 400 μg/mL showed no cytotoxicity in either A549 or A549/DDP after 72 h-treatment with it. The inhibited concentration of 50%(IC50) observed for DDP was(0.79 ± 0.05) μg/mL in A549 and(13.2 ± 1.1) in A549/DDP respectively. IC50 was reduced to 2.57 ± 0.05 μg/mL in A549/DDP treated by rh-Endostatin below the non-cytotoxic concentrations in combination with DDP, with a reversal fold(RF) of 5.14 and a relative reversal rate of 85.6%. Apoptotic rates were 2.01%, 13.47% and 29.26% respectively for cells treated with rh-Endostain, DDP, and the combination. The rate of the A549/DDP control group was 0.99%. The expression level of P-gp or Topo-II was higher in A549/DDP cells than in A549 cells. Rh-Endostatin may partially reverse DDP-resistance in A549/DDP cells in vitro, with a probable mechanism related to lowering expression of P-gp and Topo-II. Conclusion: Rh-Endostatin of non-cytotoxic dose partially reversed cisplatin resistance in cisplatin-resistant human lung adenocarcinoma cell line A549/DDP. Rh-Endostatin reversed the resistance of A549/DDP cells to DDP, which may be related to decreased protein expression of P-gp and Topo-II in A549/DDP cells.
文摘Objective: To clone multidrug resistance (MDR) related genes in lung adenocarcinoma cell lines. Methods: The differentially expressed cDNA fragments between A549 and A549 DDP cells were analyzed by mRNA differential display PCR(DD RT-PCR). The fragments thus obtained were further analyzed by DNA sequencing and Northern blotting. Results: Three differentially expressed cDNA fragments were obtained and confirmed by Northern blot. Sequence analysis revealed that two of them were novel and one was 100% identical with ICE gene. Conclusion: Analyzing differentially expressed fragment between A549 and A549 DDP cells may be helpful for finding new MDR related genes. The drug resistance of A549 DDP cells may be related to the inhibition or down-regulation of ICE gene.
基金This work was supported by a grant fromChina Scholarship Council (No.20842007).
文摘Objective： Even though radiotherapy plays a major role in the local treatment of non-small cell lung cancer （NSCLC）, little is known about the molecular effects of irradiation in this tumor. In the present study, we examined two NSCLC cell lines for their endogenous production of TNF-α after irradiation. To investigate the radiation-induced TNF-α production in NSCLC cell lines. Methods： Two human NSCLC cell lines （A549： squamous; NCI-H596： adenosquamous） were investigated for their TNF-α mRNA （real-time RT-PCR） after exposure to different irradiation doses （2, 5, 10, 20, 30, 40 Gy） and time intervals （1, 3, 6, 12, 24, 48 or 72 h）. The TNF-α mRNA expression was quantified by real-time RT-PCR. The clonogenic survival was evaluated after irradiation with 2, 4, 6 and 8 Gy. Results： Non-irradiated NSCLC cells exhibited no or very low TNF-α expression. For the NCI-H596 cell line, TNF-α expression was significantly elevated 1～12 h （maximum 6h： 568fold increase relative to unirradiated cells） in a time-dependent manner. The radiation-induced increase could be observed after irradiation with 2 Gy reaching maximal at 40 Gy, with 83 times higher than normal controls. The clonogenic survival of these cell lines was nearly identical. Conclusion： NCI-H596 cells produce significant quantities of TNF-α following irradiation in a time- and dose-dependent manner. The pro-inflammatory cytokine TNF-α is a key mediator for the pathogenesis of radiation pneumonitis. Radiation-induced endogenous TNF-α expression in NSCLC cells may affect the normal lung adjacent to the tumor and may be associated with an adverse clinical outcome of the patient.
文摘背景白藜芦醇不仅具有抗肿瘤作用,其还能增强多种化疗药物的化疗敏感性,但其对食管癌耐药细胞的顺铂敏感性的作用尚不清楚.目的探讨白藜芦醇逆转食管癌细胞Eca109/DDP的耐药效应并从铁死亡的角度分析其潜在的作用机制.方法采用MTT法确定白藜芦醇和顺铂的最佳作用时间和浓度;检测细胞增殖、细胞内丙二醛(malondialdehyde,MDA)、谷胱甘肽(glutathione,GSH)、活性氧(reactive oxygen species,ROS)及铁离子的水平;Western blot检测铁死亡相关调控因子酰基辅酶A合成酶长链家族成员4(acyl coenzyme A synthetase long chain family member 4,ACSL4)、铁蛋白重链(ferritin heavy chain,FTH)、谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)和肿瘤蛋白53(tumor protein 53,P53)的蛋白表达情况.结果MTT检测结果显示,相较于单用顺铂,联用白藜芦醇对Eca109/DDP细胞的生长抑制作用较为显著(P<0.05).此外,白藜芦醇和顺铂联用可显著降低Eca109/DDP细胞克隆形成数(P<0.05),增加细胞内铁离子、MDA和ROS水平(P<0.05),降低GSH水平(P<0.05).铁死亡抑制剂(ferrostatin-1,Fer-1)和铁离子螯合剂(deferoxamine,DFO)可部分逆转白藜芦醇对细胞增殖的抑制作用(P<0.05).Western blot的结果显示相较于其他组,白藜芦醇和顺铂联用组的FTH和GPX4的蛋白表达显著降低(P<0.05),而ACSL4和P53的蛋白表达显著增加(P<0.05).结论白藜芦醇可通过铁死亡抑制Eca109/DDP细胞的增殖并逆转顺铂耐药.
文摘目的:探讨叉头框转录因子M1(FoxM1)对人宫颈癌顺铂耐药株Hela/DDP增殖、侵袭、凋亡的影响及其机制。方法:将Hela/DDP细胞分为空白组(常规培养,不予任何处理)、正常对照(NC)组(转染空白干扰质粒)、低表达组和过表达组。低表达组转染siRNA-FoxM1下调Hela/DDP细胞中FoxM1表达,过表达组转染pcDNA3.1-FoxM1上调Hela/DDP细胞中FoxM1表达。采用RT-qPCR法检测FoxM1 m RNA表达水平,CCK-8检测细胞活力,流式细胞仪检测细胞凋亡,Transwell小室检测细胞侵袭能力。结果:FoxM1 mRNA在Hela细胞中的表达水平低于Hela/DDP细胞(P<0.05)。空白组与NC组中FoxM1 mRNA、增殖率、凋亡率、侵袭细胞数及HSP70、S100A9蛋白表达水平比较,差异均无统计学意义(P>0.05)。与空白组比较,低表达组细胞活力和侵袭能力及FoxM1 mRNA、HSP70蛋白表达水平降低,凋亡率和S100A9蛋白表达水平升高(P<0.05),与空白组比较,过表达组细胞活力和侵袭能力及FoxM1 m RNA、HSP70蛋白表达水平升高,凋亡率和S100A9蛋白表达水平降低(P<0.05)。与低表达组比较,过表达组细胞活力和侵袭能力及FoxM1 mRNA、HSP70蛋白表达水平升高,凋亡率和S100A9蛋白表达水平降低(P<0.05)。结论:下调FoxM1表达可抑制HSP70表达,促进S100A9表达,调控宫颈癌细胞恶性行为,从而提高宫颈癌顺铂耐药细胞株对顺铂化疗的敏感性。
