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
Our previous study has proven that tea polyphenol has a role in lung neoplasms. The present communication was to investage the anti-proliferation effect of tea polyphenol on the PG cells, which was a high metastatic h...Our previous study has proven that tea polyphenol has a role in lung neoplasms. The present communication was to investage the anti-proliferation effect of tea polyphenol on the PG cells, which was a high metastatic human lung carcinoma cell line, by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide (MTT) cell viability assay, and to study the change of intracellular calcium concentration, connexin43 (Cx43) expression, gap junctional intercellular communication (GJIC) and cell cycle distribution after the tea polyphenol treatment by laser scanning confocal microscopy and flow cytometry. The results showed that 1) tea polyphenol could kill the PG cells in a dose-depent manner via inhibiting the PG cell proliferation and blocking the PG cell cycle progression staying in G0/G1 phase and not transfering in S and G2/M phases to reduce the PG cell proliferation index;2) the increases of intracellular calcium concentration, GJIC and Cx43 expression were related with the tea polyphenol doses. The data suggested that tea polyphenol could inhibit the growth of PG cells, which mechanism was associated with the up-regulation of GJIC.展开更多
Objective: Aurora A kinase representing a family of evolutionarily conserved mitotic serine/threonine kinases has been found elevated in human lung adenocarcinoma cell line A549. It is suggested that the overexpressio...Objective: Aurora A kinase representing a family of evolutionarily conserved mitotic serine/threonine kinases has been found elevated in human lung adenocarcinoma cell line A549. It is suggested that the overexpression of Aurora A con- tributes to the carcinogenesis, chromosomal instability (CIN), and de-differentiation of lung cancers. To address its possibility as a therapeutic target for lung cancer, we employed the antisense oligodeoxynucleotide (ASODN) technique to inhibit Aurora A expression and investigate its effects on tumor growth and cell cycle of A549, as well as the chemosensitivity to paclitaxel. Methods: Aurora A ASODN was synthesized and transfected into A549 cells by lipofectAMINE 2000. Aurora A mRNA and protein expression were examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot respec- tively. Cell cycle distribution was observed by flow cytometer. MTT assay was used to evaluate cell inhibition ratio before and after transfection. Results: The proliferation of the A549 cells was inhibited by Aurora A ASODN dose and time dependently. It was also observed that the IC50 of A549 cells after 48 hours’ treatment of ASODN was about 300 nmol/L and under such circumstances, the Aurora A mRNA and protein expression significantly decreased (P < 0.05), along with the induction of ac- cumulation of cells in S phase and the G2-M transition. Furthermore, cell inhibition ratio of the combination of Aurora A ASODN and paclitaxel was higher significantly than paclitaxel (P < 0.05) or Aurora A ASODN alone (P < 0.05). Conclusion: Inhibition of Aurora A expression can result in the suppression of cell growth and chemosensitizing activity to paclitaxel in human lung cancer cell line A549.展开更多
Background Microwaves have other biological effects on cancer as well besides killing tumor cells by coagulation.Some studies showed that microwaves may induce apoptosis in some tumor cells. The apoptotic effect of mi...Background Microwaves have other biological effects on cancer as well besides killing tumor cells by coagulation.Some studies showed that microwaves may induce apoptosis in some tumor cells. The apoptotic effect of microwaves may help in clinic to remove residual malignant cells nearby the primary lesion and avoid relapse subsequently. However,there is little evidence on this subject from lung cancer. We studied the effect of microwaves on inducing apoptosis in the human lung carcinoma cell line A549 cells, aiming to identify its effect on apoptosis.Methods A549 cells were radiated by various intensities and durations of microwaves. Apoptosis induction in A549 cells was analyzed by morphological observations, tetrazolium blue color method （MTT） assays, flow cytometery,immunohistochemistry, and image analyses.Results Morphological changes in A549 cells, including cell shrinking and nuclear pycnosis, were observed after microwave radiation. Microwaves significantly inhibited metabolic activities and induced apoptosis in A549 cells. The results of the MTT assay showed a significant decrease of cell activities in all the radiation groups compared with the normal control （P ＜0.01）. The low point of cell activities often appeared at 6-12 hours after radiation. Apoptosis was also confirmed by flow cytometery. The early stage apoptotic rate reached 6.10%-17.98% and the advanced stage apoptotic rate ＋ necrosis rate reached 8.04%-44.06% at 6 hours after microwave irradiation, in contrast to 2.32% and 4.10% in the respective control groups. Down-regulation of Bcl-2 expression and up-regulation of p53 expression were observed by immunohistochemistry after radiation. In most treated groups, the down-regulation of Bcl-2 expression reached its lowest level at 3-6 hours after radiation （integrated optical density （IOD）-6 hours： 2.13±0.08-5.14±0.13 vs. control： 5.79±0.10, P＜0.01 ） and the up-regulation of P53 expression peaked at about 3 hours （IOD-3 hours： 2.61±0.13-8.07±0.11 vs. control：1.29±0.07, P ＜0.01）. Cell damage, apoptosis, and protein expression levels in the samples differed depending on the radiation intensity and duration.Conclusions Microwaves can promote apoptosis in A549 cells. The effect depends on the duration and dosage of microwave radiation. Bcl-2 and p53 proteins may be involved in the apoptotic process of A549 cells induced by microwaves.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
In order to investigate the inhibitory effects of Endostar(rh-endostatin,YH-16)in combination with radiotherapy on lung adenocarcinoma A549 in mice and the interaction mechanisms of combined therapy,the transplantatio...In order to investigate the inhibitory effects of Endostar(rh-endostatin,YH-16)in combination with radiotherapy on lung adenocarcinoma A549 in mice and the interaction mechanisms of combined therapy,the transplantation tumor models of A549 lung adenocarcinoma were established.When the largest diameter of tumor reached 1.0cm,all nude mice were randomly divided into 4 groups:Endostar group,radiotherapy group,radiotherapy plus Endostar(combined treatment)group,and control group(n=6 in each group).The largest d...展开更多
Obejctive To detect the influence of antisense s oligodeoxynucleotides (S ODNs) of bd 2 and multidrug resistamce associated protein (MRP) genes multidrug resistance associated protein gene and bcl 2 antisen...Obejctive To detect the influence of antisense s oligodeoxynucleotides (S ODNs) of bd 2 and multidrug resistamce associated protein (MRP) genes multidrug resistance associated protein gene and bcl 2 antisense S oligodeoxynucleotides on cisplatin resistant lung adenocarcinoma cell line A 549 DDP which overexpresses both bcl 2 and MRP Methods A 549 DDP cells were treated with sense and antisense S ODN mediated by lipofection Expression of MRP and bcl 2 mRNA and protein in the treated cells was measured by RT PCR and flow cytometry (FCM), respectively Apoptosis was identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT) mediated biotin dUTP nick end labeling(TUNEL) The degree of drug resistance of the treated cells was detected by a cell viability 3' [4,5 dimethylthiazol 2 yl] 2,5 diphenyl tefrazolium bromide thiazolylblue (MTT) assay Results Expression of bcl 2 and MRP significantly decreased in the cells treated with bcl 2 or/and MRP antisense S ODN for 48h as compared to the cells untreated and sense treated ( P <0 05) Resistance to cisplatin in the cells treated with bcl 2 or/and MRP antisense S ODN decreased by 60 6% (6 5 times), 56 4% (7 2 times) and 71 0% (4 8 times), respectively, which paralleled the decrease of bcl 2 and MRP expression Similarly, the resistance to etoposide and epirubicin in antisense treated cells also reduced in parallel to decreases of the two gene expressions The drug resistance in sense treated cells was similar to that in untreated cells Statistically significant dose and concentration dependent increases of apoptotic cells were observed in the groups exposed to 100?μmol/L cisplatin for 48?h after treatment by bcl 2 or/and MRP antisense Conclusion Bcl 2 and MRP were at least additive and possibly synergistic in conferring drug resistance in a cisplatin resistant lung adenocarcinoma cell line Antisense S ODN could attenuate drug resistance by promoting cells apoptosis, which might lead to a new treatment for patients with non small cell lung cancers (NSCLCs) who are refractory to conventional chemotherapy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Our previous study has proven that tea polyphenol has a role in lung neoplasms. The present communication was to investage the anti-proliferation effect of tea polyphenol on the PG cells, which was a high metastatic human lung carcinoma cell line, by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide (MTT) cell viability assay, and to study the change of intracellular calcium concentration, connexin43 (Cx43) expression, gap junctional intercellular communication (GJIC) and cell cycle distribution after the tea polyphenol treatment by laser scanning confocal microscopy and flow cytometry. The results showed that 1) tea polyphenol could kill the PG cells in a dose-depent manner via inhibiting the PG cell proliferation and blocking the PG cell cycle progression staying in G0/G1 phase and not transfering in S and G2/M phases to reduce the PG cell proliferation index;2) the increases of intracellular calcium concentration, GJIC and Cx43 expression were related with the tea polyphenol doses. The data suggested that tea polyphenol could inhibit the growth of PG cells, which mechanism was associated with the up-regulation of GJIC.
基金Hubei Provincial Science and Technology Key Program Foundation (No. 2004AA304B08)
文摘Objective: Aurora A kinase representing a family of evolutionarily conserved mitotic serine/threonine kinases has been found elevated in human lung adenocarcinoma cell line A549. It is suggested that the overexpression of Aurora A con- tributes to the carcinogenesis, chromosomal instability (CIN), and de-differentiation of lung cancers. To address its possibility as a therapeutic target for lung cancer, we employed the antisense oligodeoxynucleotide (ASODN) technique to inhibit Aurora A expression and investigate its effects on tumor growth and cell cycle of A549, as well as the chemosensitivity to paclitaxel. Methods: Aurora A ASODN was synthesized and transfected into A549 cells by lipofectAMINE 2000. Aurora A mRNA and protein expression were examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot respec- tively. Cell cycle distribution was observed by flow cytometer. MTT assay was used to evaluate cell inhibition ratio before and after transfection. Results: The proliferation of the A549 cells was inhibited by Aurora A ASODN dose and time dependently. It was also observed that the IC50 of A549 cells after 48 hours’ treatment of ASODN was about 300 nmol/L and under such circumstances, the Aurora A mRNA and protein expression significantly decreased (P < 0.05), along with the induction of ac- cumulation of cells in S phase and the G2-M transition. Furthermore, cell inhibition ratio of the combination of Aurora A ASODN and paclitaxel was higher significantly than paclitaxel (P < 0.05) or Aurora A ASODN alone (P < 0.05). Conclusion: Inhibition of Aurora A expression can result in the suppression of cell growth and chemosensitizing activity to paclitaxel in human lung cancer cell line A549.
文摘Background Microwaves have other biological effects on cancer as well besides killing tumor cells by coagulation.Some studies showed that microwaves may induce apoptosis in some tumor cells. The apoptotic effect of microwaves may help in clinic to remove residual malignant cells nearby the primary lesion and avoid relapse subsequently. However,there is little evidence on this subject from lung cancer. We studied the effect of microwaves on inducing apoptosis in the human lung carcinoma cell line A549 cells, aiming to identify its effect on apoptosis.Methods A549 cells were radiated by various intensities and durations of microwaves. Apoptosis induction in A549 cells was analyzed by morphological observations, tetrazolium blue color method （MTT） assays, flow cytometery,immunohistochemistry, and image analyses.Results Morphological changes in A549 cells, including cell shrinking and nuclear pycnosis, were observed after microwave radiation. Microwaves significantly inhibited metabolic activities and induced apoptosis in A549 cells. The results of the MTT assay showed a significant decrease of cell activities in all the radiation groups compared with the normal control （P ＜0.01）. The low point of cell activities often appeared at 6-12 hours after radiation. Apoptosis was also confirmed by flow cytometery. The early stage apoptotic rate reached 6.10%-17.98% and the advanced stage apoptotic rate ＋ necrosis rate reached 8.04%-44.06% at 6 hours after microwave irradiation, in contrast to 2.32% and 4.10% in the respective control groups. Down-regulation of Bcl-2 expression and up-regulation of p53 expression were observed by immunohistochemistry after radiation. In most treated groups, the down-regulation of Bcl-2 expression reached its lowest level at 3-6 hours after radiation （integrated optical density （IOD）-6 hours： 2.13±0.08-5.14±0.13 vs. control： 5.79±0.10, P＜0.01 ） and the up-regulation of P53 expression peaked at about 3 hours （IOD-3 hours： 2.61±0.13-8.07±0.11 vs. control：1.29±0.07, P ＜0.01）. Cell damage, apoptosis, and protein expression levels in the samples differed depending on the radiation intensity and duration.Conclusions Microwaves can promote apoptosis in A549 cells. The effect depends on the duration and dosage of microwave radiation. Bcl-2 and p53 proteins may be involved in the apoptotic process of A549 cells induced by microwaves.
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.
文摘In order to investigate the inhibitory effects of Endostar(rh-endostatin,YH-16)in combination with radiotherapy on lung adenocarcinoma A549 in mice and the interaction mechanisms of combined therapy,the transplantation tumor models of A549 lung adenocarcinoma were established.When the largest diameter of tumor reached 1.0cm,all nude mice were randomly divided into 4 groups:Endostar group,radiotherapy group,radiotherapy plus Endostar(combined treatment)group,and control group(n=6 in each group).The largest d...
文摘Obejctive To detect the influence of antisense s oligodeoxynucleotides (S ODNs) of bd 2 and multidrug resistamce associated protein (MRP) genes multidrug resistance associated protein gene and bcl 2 antisense S oligodeoxynucleotides on cisplatin resistant lung adenocarcinoma cell line A 549 DDP which overexpresses both bcl 2 and MRP Methods A 549 DDP cells were treated with sense and antisense S ODN mediated by lipofection Expression of MRP and bcl 2 mRNA and protein in the treated cells was measured by RT PCR and flow cytometry (FCM), respectively Apoptosis was identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT) mediated biotin dUTP nick end labeling(TUNEL) The degree of drug resistance of the treated cells was detected by a cell viability 3' [4,5 dimethylthiazol 2 yl] 2,5 diphenyl tefrazolium bromide thiazolylblue (MTT) assay Results Expression of bcl 2 and MRP significantly decreased in the cells treated with bcl 2 or/and MRP antisense S ODN for 48h as compared to the cells untreated and sense treated ( P <0 05) Resistance to cisplatin in the cells treated with bcl 2 or/and MRP antisense S ODN decreased by 60 6% (6 5 times), 56 4% (7 2 times) and 71 0% (4 8 times), respectively, which paralleled the decrease of bcl 2 and MRP expression Similarly, the resistance to etoposide and epirubicin in antisense treated cells also reduced in parallel to decreases of the two gene expressions The drug resistance in sense treated cells was similar to that in untreated cells Statistically significant dose and concentration dependent increases of apoptotic cells were observed in the groups exposed to 100?μmol/L cisplatin for 48?h after treatment by bcl 2 or/and MRP antisense Conclusion Bcl 2 and MRP were at least additive and possibly synergistic in conferring drug resistance in a cisplatin resistant lung adenocarcinoma cell line Antisense S ODN could attenuate drug resistance by promoting cells apoptosis, which might lead to a new treatment for patients with non small cell lung cancers (NSCLCs) who are refractory to conventional chemotherapy
