THE EFFECT OF RNAI-MEDIATED GENE SILENCING ON HER-2/NEU GENE EXPRESSION IN LUNG ADENOCARCINOMA CELLS

Objective: Her-2/neu protein overexpression has been demonstrated in Non-small cell lung cancer, especially in lung adenocarcinoma. Its overexpression often indicates a poor prognosis. Therapeutic agents against her-2/neu have been intensively sought over the past decades. The objective of this paper is to investigate the effect of chemically synthesized siRNA targeting her-2/neu on her-2/neu dysregulated human lung adenocarcinoma cells. Methods: Calu-3 cells were transfected with siRNAs formulated LipofectAMINE 2000. The her-2/neu mRNA and protein levels were detected by RT-PCR and flow cytometry (FCM). The biological morphology and growth inhibition of calu-3 cells were observed with light microscopy and MTT assay, respectively. The cell cycle and apoptosis rate were analyzed by FCM. Results: siRNA targeting Her-2/neu down-regulated the transcription of her-2/neu oncogene and protein level. Slowed cell proliferation and cell cycle arrest at G0/1 stage could be also observed, accompanied with enhanced cell apoptosis. Conclusion: Specific siRNA targeting her-2/neu can effectively inhibit her-2/neu expression in her-2/neu overexpressing calu-3 cell lines. siRNA-mediated gene silencing may be a useful therapeutic strategy for cancer.

Regulation Effect of miR-34a Expression on Radiosensitivity of Lung Adenocarcinoma Cells by Targeting Bcl-2 and CDK4/6 Signaling Pathways

Objective: Radiotherapy has been widely used to treat lung cancer. However, non-small lung cancer cells are insensitive to radiation, diminishing their radiotherapy effects. Although the radiosensitivity of the non-small lung cancer cells was reported to be enhanced through regulating miR-34a, the regulation effects of miR-34a expression on radiosensitivity of lung adenocarcinoma cells through target genes CDK4, CDK6, CyclinD1, and Bcl-2/Bax have not been systematically investigated. Methods: In this study, we investigated the effect of miR-34a expression on the Bcl-2, CDK4, and CDK6 pathways in lung adenocarcinoma cells, to provide new insights into the sensitization treatment of lung cancer. We first studied the effect of miR-34a expression on H1299 and A549 cell activity. Then to investigate the mechanisms of radiosensitivity, we focused on apoptosis, cell cycle, and target genes. Results: We find that overexpression of miR-34a in lung adenocarcinoma cells inhibits cell activity, and improves radiosensitivity. Specifically, overexpression of miR-34a suppresses the expression of target genes CDK4, CDK6, CyclinD1, and Bcl-2/Bax, which leads to cell cycle arrest and promotes apoptosis of lung adenocarcinoma cells. Conclusions: Overall, our results demonstrate that the overexpression of miR-34a enhances the radiosensitivity of lung adenocarcinoma cells, indicating that miR-34a is a sensitizer for lung adenocarcinoma radiotherapy.

Effects of PI3K Inhibitor NVP-BKM120 on Acquired Resistance to Gefitinib of Human Lung Adenocarcinoma H1975 Cells

The effects of class I PI3K inhibitor NVP-BKM120 on cell proliferation, cell cycle distri- bution, cellular apoptosis, phosphorylation of several proteins of the PI3K/AKT signaling pathway and the mRNA expression levels of HIFl-ct, VEGF and MMP9 in the acquired gefitinib resistant cell line H1975 were investigated, and whether NVP-BKM120 can overcome the acquired resistance caused by the EGFR T790M mutation and the underlying mechanism were explored. MTT assay was performed to detect the effect of gefitinib, NVP-BKM120, NVP-BKM120 plus 1 ~unol/L gefitinib on growth of H1975 cells. The distribution of cell cycle and apoptosis rate of H1975 cells were examined by using flow cytometry. The mRNA expression levels of tumor-related genes such as HIFI-a, VEGF and MMP9 were detected by using real-time quantitative PCR. Western blotting was used to detect the ex- pression level of phosphorylated proteins in the PI3K/AKT signaling pathway, such as Ser473-p-AKT, Ser235/236-p-S6 and Thr70-p-4E-BP1, as well as total AKT, $6 and 4E-BP1. The results showed that the NVP-BKM120 could inhibit the growth of H1975 cells in a concentration-dependent manner, and H1975 cells were more sensitive to NVP-BKM120 than gefitinib （IC50：1.385 vs. 15.09 ~mol/L respec- tively）, whereas combination of NVP-BKM120 and gefitinib （1 ~trnol/L） did not show more obvious ef- fect than NVP-BKM120 used alone on inhibition of cell growth （P〉0.05）. NVP-BKM120 （1 ~unol/L） increased the proportion ofH1975 cells in G0~G1 phase and the effect was concentration-dependent, and 2 ~maol/L NVP-BKM120 promoted apoptosis ofH1975 cells. There was no significant difference in the proportion of H1975 cells in G0-G1 phase and apoptosis rate between NVP-BKM120-treated alone group and NVP-BKM120 plus genfitinib （1 ~unol/L）-treated group or between DMSO-treated control group and gefitinib （1 Ixmol/L）-treated alone group （P〉0.05 for all）. It was also found that the mRNA expression levels of these genes were down-regulated by NVP-BKM120 （1 ~unol/L）, and NVP-BKM120 （1 ~tmol/L） or NVP-BKM120 （1 pmol/L） plus gefitinib （1 ~tmol/L） obviously inhibited the activation of Akt, $6 and 4E-BP1 as compared with control group, but single use of gefitinib （1 pmol/L） exerted no significant effect. These data suggested that NVP-BKM120 can overcome gefitinib resistance in H1975 cells, and the combination of NVP-BKM120 and gefitinib did not have additive or synergistic effects. It was also concluded that NVP-BKM120 could overcome the acquired resistance to gefitinib by down-regulating the phosphorylated protein in PI3K/AKT signal pathways in H1975 cells, but it could not enhance the sensitivity of H 1975 cells to gefitinib.

Effects of paclitaxel on cell proliferation and apoptosis and its mechanism in human lung adenocarcinoma A549 cells

Objective： To investigate the effect of paclitaxel on cell proliferation and apoptosis of human lung adenocarcinoma A549 cells line and its mechanism in vitro. Methods ： Cell growth inhibition of paclitaxel on A549 cells was analyzed by MTT assay. Cell apoptosis was detected by DNA cytofluorometry, Hoechst33258 staining when treated with paclitaxel for 48 hours. Meanwhile, Cell cycle and apoptotic rate were analyzed by flow cytometry. The protein expressions of Bax and Bcl-2 were studied by Western Blot. Results： Paclitaxel inhibited the proliferation of A549 cells in a time-and dose-dependant manner. Hoechst33258 staining indicated that apoptosis was induced by paclitaxel. After treated for 48 hours, cell apoptosis rates of 25 nmo1/L, 50 nmol/L and 100 nmol/L paclitaxel groups were 11.52 ± 1.94% ,17.73 ±2.53%, and 29.32 ±5.51% respectively, which were significantly higher than those of control group 5.88 ±1.07%（all P 〈 0.01 ）, and apoptosis rate increased in dose-dependant manner. Meanwhile, G2/M stage cell percentage of 25 nmol/L, 50 nmol/L and 100 nmol/L paclitaxel groups were 42.52 ± 6.25%, 40.46 ± 5.81%, and 35.34 ±6.17% respectively,which were significantly higher than that of control group 22.32 ± 3.30%（all P 〈 0.01 ）; Western blot showed that paclitaxel increased the expression of Bax and decreased the expression of Bcl-2 in dose-dependant manner. Conclusion： Paclitaxel can inhibit A549 cell proliferation in a time-and dose-dependant manner. Its mechanism may be related to arresting cell cycle in G2/M stage and induce cell apoptosis by up-modulating Bax expression and down-modulating Bcl-2 expression.

EXPERIMENTAL RESEARCH OF EFFECTIVENESS OF siRNA-Her-2/neu ON DRUG SENSITIVITY OF Her-2/neu-OVER-EXPRESSING LUNG ADENOCARCINOMA CELL LINE

Objective： Her-2/neu protein overexpression has been demonstrated in lung adenocarcinoma. Its overexpression often indicates a poor prognosis and resistance to chemotherapeutic agents. The objectives of this paper is to explore the effectiveness of double-stranded short inhibitory RNAs （siRNA） targeting Her-2/neu oncogene on the drug sensitivity of Her-2/neu-overexpressing lung adenocarcinoma cells. Methods： Lung adenocarcinoma cell line calu-3 was transfected with siRNAs formulated LipofectAMINE 2000, and Her-2/neu protein and P-gp were determined by flow cytometry （FCM）. The chemosensitivity of transfected cells to cisplatin （CDDP） was measured by MTT. Cell apoptosis detection kit （Annexin V method） was used to examine the drug induced apoptosis rate. Results： siRNA targeting Her-2/neu greatly reduced the cell surface expression of Her-2/neu protein and had no effect on P-gp. Consequently the inhibitory rate of CDDP in combination with siRNA targeting Her-2/neu was （67.1±2.3）%, while the inhibitory rates were （48.1±3.5）%, （46.3±5.9）% and （50.2±2.9）% in untreated control, empty vector and unrelated siRNA groups, respectively. The FCM results showed that the apoptosis rate of cells treated with CDDP combined with siRNAs-Her-2/neu was elevated when compared with unrelated siRNA group and empty vector group. Conclusion： Sequence specific siRNA targeting Her-2/neu was capable of enhancing the chemosensitivity of calu-3 cell to cisplatin.

Characterization of Two Human Lung Adenocarcinoma Cell Lines by Reciprocal Chromosome Painting

Lung cancer is a leading cause of cancer death worldwide. Some lung cancer patients correlate with a gas of radon besides smoking. To search for common chromosomal aberrations in lung cancer cell lines established from patients induced by different factors, a combined approach of chromosome sorting, forward and reverse chromosome painting was used to characterize karyotypes of two lung adenocarcinoma cell lines： A549 and GLC-82 with the latter line derived from a patient who has suffered long-term exposure to environmental radon gas pollution. The chromosome painting results revealed that complex chromosomal rearrangements occurred in these two lung adenocarcinoma cell lines. Thirteen and twenty-four abnormal chromosomes were identified An A549 and GLC-82 cell lines, respectively. Almost half of abnormal chromosomes in these two cell lines were formed by non-reciprocal translocations, the others were derived from deletions and duplication/or amplification in some chromosomal regions. Furthermore, two apparently common breakpoints, HSA8q24 and 12q14 were found in these two lung cancer cell lines.

The Inhibitory Effects of Rh-endostatin(YH-16) in Combination with Radiotherapy on Lung Adenocarcinoma A549 in Mice and the Underlying Mechanisms

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...

Empirical studies about quercetin increasing chemosensitivity on human lung adenocarcinoma cell line A549

Objective： The present study was designed to investigate whether quercetin exerts increasing chemosensitivity on human lung adenocarcinoma cells when quercetin combined with cisplatin （DDP） and vincristine （VCR） in vitro respectively and its possible antitumor mechanism. To provide experimental proof for clinical combination application. Methods： Using intermittent administration of high dose VCR, human lung adenocarcinoma sensitive cell line （A549/S） was induced to VCR- resistant human lung adenocarcinoma cell line （A549NCR）. MTT assay was adapted for examing the 50% inhibition （IC50） value of DDP and VCR on A549/S and A549/VCR when quercetin combined with DDP and VCR respectively. Results： IC50 of DDP on A549/S and A549/VCR was 10.18 and 12.35 mg/L, and the IC50 of VCR on the two cell lines was 1.21 and 12.77 rag/L, respectively. The resistance fold of A549/VCR on VCR and DDP was 10.55 and 121, respectively. When quercetin at concentration of 50, 100 and 200 pmol/L in combination with DDP and VCR respectively, the IC50 of DDP and VCR on A549/S and A549/VCR were obvious decreased （P 〈 0.05 - P 〈 0.01）. Conclusion： The experiment results suggested that quercetin could increase the chemosensitivity and partly revise the resistance of A549NCR.

Significance of the Expression of Rho-GDP Dissociation Inhibitor β,γ in Lung Squamous Cell Carcinoma and Adenocarcinoma

Objective： To study the expression of Rho-GDP dissociation inhibitor β,γ （Rho-GDIβ, Rho-GDIγ） in lung squamous cell carcinoma and adenocarcinoma and its relationship with the expression of RhoC （Ras homologus oncogenes C） and clinicopathologic parameters. Methods： Western blot assay was employed for Rho-GDIβ, Rho-GDIγand RhoC in lung squamous cell carcinoma and adenocarcinoma and non-neoplastic lung tissues of 37 cases with fresh specimens. Results： The study showed that Rho-GDIβ, Rho-GDIγ and RhoC were expressed in lung cancer and non-neoplastic lung tissues, the level in lung cancer tissue was much higher than that in non-neoplastic tissues （P〈0.001）. In lung cancer, the expression of Rho-GDIβwas much higher in patients with lymph node metastasis （P=0.021）, and the expression of Rho-GDIγ was much higher in poorly differentiated tumor than in well-differentiated and moderately differentiated tumor, but both of them were not correlated with other clinicopathologic parameters. The expressions of Rho-GDIβ and Rho-GDIγ were not correlated with the expression of RhoC. Conclusion： In lung cancer, Rho-GDIβand Rho-GDIγ may play a role in the tumorigenesis, Rho-GDIβ may promote metastasis, and Rho-GDIγ may have some relationship with differentiation.

Study of Pravastatin on Intervention of the Apoptosis in Human Lung Adenocarcinoma A549

Lung cancer is one of the serious threats to human health and life of malignant diseases, on a global scale; it has become one of the major lung cancer deaths. Due to the growth of the tumor and the main reason is that apoptosis is inhibited, therefore, it can induce apoptosis in lung cancer cells that is an important measure for the treatment of lung cancer, which is one of the effective means to reduce lung cancer mortality. In this paper, A549 human lung adenocarcinoma cell line, for example, has the use of chemical genetics of these emerging technological platforms, research pravastatin on apoptosis in human lung adenocarcinoma A549 intervention, while providing a theoretical basis for the development of new lung cancer therapy.

Simvastatin Action Is Not Related to HDAC2 Expression in Non-Small Cell Lung Cancer (NSCLC)

In this study, we lowered the expression of HDAC2 protein, to evaluate the effects of simvastatin on the biochemical pathways involved in inflammatory and metastatic response. The model used is the non-small cell lung cancer line (GLC-82). Trypan blue staining for assessing vital cell number to be seed and MTT assay was used as cell proliferation test. Lentivus for HDAC2 was used to silence its mRNA. Western blotting analysis was used for protein extracts, and ELISA was done on culture media for cytokines (IL-6, IL-8 and TNF-alpha) release. Hydrogen peroxide (H2O2) was used to induce oxidative stress. Our results have shown that Lentivirus containing the shHDAC2 in GLC-82 cells was able to reduce protein expression of HDAC2. In the GLCshHDAC2 cell line obtained, H2O2 induced a significant increase in cytokines release and ERK1/2 phosphorylation (P 0.01);a significant decrease of RECK activation (P 0.01);a significant increased activation (P 0.01) of both MMP-2 and MMP-9 and an increased activation of NF-κB, MyD88, TRAF-6, TRADD, TRAF-2. In GLCshHDAC2 cell, the treatment with simvastatin (30 μM), significantly affected all the biochemical markers examinated (P 0.01). In conclusion, from our report emerge, that simvastatin is able per se to inhibit oxidative stress in lung cancer cells, overcoming HDAC2 expression.

TAXOL INDUCES CELL DEATH WITH CYTOPLASM VACUOLIZATION IN PARAPTOSIS-LIKE BUT NOT ONCOSIS FASHION IN ASTC-a-1 CELLS

Recently,we found that high concentration of taxol(70μM)induced cell death with cytoplasm vacuolization,the typical characteristic of both paraptosis and oncosis,in human lung carcinoma(ASTC-a-1)cells.This report was designed to further deternine the form of taxo-induced cell death with cytoplasm vacuolization.It is generally coneidered that the cytoplasm vacuolization in oncosis due to the sweling of endoplasmic reticulum(ER),mitochondria,lysosomes and muclei occurs after the loss of mitochondrial mermbrane potential(△ψm).However,flow cytometry(FCM)analysis showed that taxol induced cy toplsm vacuolization preceded the loss of(△ψm).Moreover,taxol treatment did not induce the collapse of microtubule,the ty pical characteristic of oncosis.These data demonstrated that taxol-induced cell death with cytoplasm vacuolization is not onoosis.FCM analysis by Annexin V-FTTC/PI apoptosis detection kit further demoustrated that taxol-induced cell death with cytoplasm vacuolization is not apoptosis.In conclusion,in combination with our recent in ritro and in vito data,this report further demonstrates that high concentration of taxol induces cell death with cytoplasm vacuolization in paraptosis like but not oncosis fashion.

A benzoxazine derivative specifically inhibits cell cycle progression in p53-wild type pulmonary adenocarcinoma cells

A fundamental aspect of cancer development is cancer cell proliferation.Seeking for chemical agents that can interfere with cancer cell growth has been of great interest over the years.In our study,we found that a benzoxazine derivative,(6-tert-butyl-3,4-dihydro-2Hbenzo[b][1,4]oxazin-3-yl)methanol(TBM),could inhibit cell growth and caused significant cell cycle arrest in pulmonary adenocarcinoma A549 and H460 cells with wild-type p53,while not affecting the cell cycle distribution in p53-deleted H1299 lung adenocarcinoma cells.Since P53 plays an important role in regulating cell cycle progression,we analyzed the protein level of p53 by Western blot,and detected a significant elevation of p53 level after TBM treatment in A549 and H460 cells.The data suggested that TBM might specifically inhibit the proliferation of p53 wild-type lung adenocarcinoma cells through a p53-dependent cell cycle control pathway.More interestingly,results indicated that TBM might serve as a useful tool for studying the molecular mechanisms of lung cancer cell growth and cell cycle control,especially for the biologic process regulated by P53.

Chemical compositions,cytotoxicity and antioxidant activity of the endophytic fungus Fusarium napiforme isolated from Psidium guajava

The bioactive secondary metabolites from the endophytic fungus Fusarium napiforme was evaluated for the cytotoxic effect and antioxidant activity.The total antioxidant capacity(TAC)of the extract was determined by 2,2-diphenyl-1-picrylhydrazyl(DPPH),phosphomolybdate,and reducing power assay methods.The cytotoxicity of the extract was evaluated against lung adenocarcinoma(A549)cells and mouse embryo fibroblast(NIH3T3)cells by methyl thiazolyl tetrazolium(MTT)method.The major composition of the crude extract was identified by the Gas Chromatography-Mass Spectrometry(GC-MS)analysis.Estimation of the endophyte crude extract revealed a high amount of the total flavonoid content(TFC)and total phenolic content(TPC).The extract showed high cytotoxic activity against the A549 cell line with the mean cytotoxicity of 69.74±0.49%.The extract did not show any cytotoxic effect against the NIH3T3 cell line.The extract exhibited high antioxidant activity as a function of the concentrations.At a test concentration of 1 mg ml-1,the extract showed the highest inhibition against DPPH radical at 75.4607%±0.47688,ferric ion reducing power at 0.882±0.0120,and 255.434±21.404 AAE/g of the extract by phosphomolybdenum assay(PMA).There is a significant correlation between TPC and antioxidant activity at p<0.05.The correlation between reducing power and DPPH is significant at p<0.01.The major types of bioactive compounds identified by the GC-MS have shown the presence of nine major compounds.This result strongly exhibits that the endophyte F.napiforme can be a potential source for the formulation of natural anticancer drugs and protecting the body from oxidative damages.

Adenocarcinoma transformed into squamous cell carcinoma in non-small cell lung cancer

Non-small cell lung cancer(NSCLC)is the most common form of lung cancer which remains the deadliest malignancy worldwide(Siegel et al.,2019).In general,NSCLC can be divided into several subtypes,including adenocarcinoma(ADC),squamous cell carcinoma(SCC),adeno-squamous cell carcinoma(AD-SCC)and large cell carcinoma(LCC).

Anti-angiogenesis effect of Demethyl bryoanthrathiophene(DBT) in vitro

Objective:The aim of the study was to investigate the effect of Demethyl bryoanthrathiophene(DBT) on proliferations of human umbilical vein endothelial cells(HUVECs) and human lung adenocarcinoma cell line A549,and antiangiogenic effect of DBT on HUVECs in vitro.Methods:MTT assay was used to observe the effect of DBT on proliferations of HUVECs and A549 cells,flat plate scarification assay and tube formation in vitro test were used to observe the impact of DBT on migration and vaso-formed ability of HUVECs.The effects of DBT on apoptosis and cell cycle of HUVECs were calculated by flow cytometry.Results:MTT assay showed that treatment with DBT resulted in strong inhibition to the growth of HUVECs and A549 cells.The inhibition effects of DBT on HUVECs and A549 cells were related to dosage and times of dependency.In different doses of DBT(0.16,0.32 and 0.48 μmol/L) of flat plate scarification for 24 h,inhibition rates of DBT to migration of HUVECs were 14.70%,38.23% and 58.82%,respectively.In dose of DBT from 0.04,0.20 to 0.40 μmol/L for 24 h in tube formation,there were significance differences(P < 0.01) in the decreasing number of angiogenesis and incomplete blood vessel compared with control groups.All results showed that DBT promoted the apoptosis rate of HUVECs,and the increase of concentration of DBT accompanied the acceleration of apoptosis rate.Conclusion:DBT could inhibit the proliferations of HUVECs and A549 cells,and effectively suppress angiogenesis in vitro.

Correlation of circulating tumor DNA EGFR mutation levels with clinical outcomes in patients with advanced lung adenocarcinoma

Background:Circulating tumor DNA(ctDNA)is a promising biomarker for non-invasive epidermal growth factor receptor mutations(EGFRm)detection in lung cancer patients,but existing methods have limitations in sensitivity and availability.In this study,we used theΔCt value(mutant cycle threshold[Ct]value-internal control Ct value)generated during the polymerase chain reaction(PCR)assay to convert super-amplification-refractory mutation system(superARMS)from a qualitative method to a semi-quantitative method named reformed-superARMS(R-superARMS),and evaluated its performance in detectingEGFRm in plasma ctDNA in patients with advanced lung adenocarcinoma.Methods:A total of 41 pairs of tissues and plasma samples were obtained from lung adenocarcinoma patients who had knownEGFRm in tumor tissue and were previously untreated.EGFRm in ctDNA was identified by using superARMS.Through making use ofΔCt value generated during the detection process of superARMS,we indirectly transform this qualitative detection method into a semi-quantitative PCR detection method,named R-superARMS.Both qualitative and quantitative analyses of the data were performed.Kaplan-Meier analysis was performed to estimate the progression-free survival(PFS)and overall survival(OS).Fisher exact test was used for categorical variables.Results:The concordance rate ofEGFRm in tumor tissues and matched plasma samples was 68.3%(28/41).At baseline,EGFRm-positive patients were divided into two groups according to the cut-offΔCt value ofEGFRm set at 8.11.A significant difference in the median OS(mOS)between the two groups was observed(EGFRmΔCt≤8.11vs.>8.11:not reachedvs.11.0 months;log-rankP=0.024).Patients were divided into mutation clearance(MC)group and mutation incomplete clearance(MIC)group according to whether theΔCt value ofEGFRm test turned negative after 1 month of treatment.We found that there was also a significant difference in mOS(not reachedvs.10.4 months;log-rankP=0.021)between MC group and MIC group.Although there was no significant difference in PFS between the two groups,the two curves were separated and the PFS of MC group tended to be higher than the MIC group(not reachedvs.27.5 months;log-rankP=0.088).Furthermore,EGFRm-positive patients were divided into two groups according to the cut-off of the changes inΔCt value ofEGFRm after 1 month of treatment,which was set at 4.89.A significant difference in the mOS between the two groups was observed(change value ofΔCt>4.89vs.≤4.89:not reachedvs.11.0 months;log-rankP=0.014).Conclusions:DetectingEGFRm in ctDNA using R-superARMS can identify patients who are more likely sensitive to targeted therapy,reflect the molecular load of patients,and predict the therapeutic efficacy and clinical outcomes of patients.