Highly Efficient Labeling of Human Lung Cancer Cells Using Cationic Poly-L-lysine-Assisted Magnetic Iron Oxide Nanoparticles

Cell labeling with magnetic iron oxide nanoparticles(IONPs)is increasingly a routine approach in the cellbased cancer treatment.However,cell labeling with magnetic IONPs and their leading effects on the biological properties of human lung carcinoma cells remain scarcely reported.Therefore,in the present study the magnetic c-Fe2O3nanoparticles(MNPs)were firstly synthesized and surface-modified with cationic poly-L-lysine(PLL)to construct the PLL-MNPs,which were then used to magnetically label human A549 lung cancer cells.Cell viability and proliferation were evaluated with propidium iodide/fluorescein diacetate double staining and standard 3-(4,5-dimethylthiazol-2-diphenyl-tetrazolium)bromide assay,and the cytoskeleton was immunocytochemically stained.The cell cycle of the PLL-MNPlabeled A549 lung cancer cells was analyzed using flow cytometry.Apoptotic cells were fluorescently analyzed with nuclear-specific staining after the PLL-MNP labeling.The results showed that the constructed PLL-MNPs efficiently magnetically labeled A549 lung cancer cells and that,at low concentrations,labeling did not affect cellular viability,proliferation capability,cell cycle,and apoptosis.Furthermore,the cytoskeleton in the treated cells was detected intact in comparison with the untreated counterparts.However,the results also showed that at high concentration(400 lg m L-1),the PLL-MNPs would slightly impair cell viability,proliferation,cell cycle,and apoptosis and disrupt the cytoskeleton in the treated A549 lung cancer cells.Therefore,the present results indicated that the PLL-MNPs at adequate concentrations can be efficiently used for labeling A549 lung cancer cells and could be considered as a feasible approach for magnetic targeted anti-cancer drug/gene delivery,targeted diagnosis,and therapy in lung cancer treatment.

IONIZING RADIATION-INDUCED IL-Ia, IL-6 AND GM-CSF PRODUCTION BY HUMAN LUNG CANCER CELLS

A cell line derived from human lung cancer(AOI) was employed in the present study.A panel of cytokines were quantified by ELISA technique following cellular exposure to X-irradiation.

Inhibitory Effect of Cantharidin on Proliferation of A549 Cells

Objective： To study the inhibition of Cantharidin against the proliferation of human lung cancer A549 cells and its mechanism. Methods： MTT assay was employed to determine the inhibition of Cantharidin against proliferation of A549 cells and flow Cytometry was applied to analyze A549 cell cycle and the effect of Cantharidin on cell cycle. Results： Cantharidin showed inhibition against the proliferation of A549 cells, and the inhibition was mediated by blocking A549 cell cycle at G2/M phase significantly. Conclusion： Cantharidin exhibits inhibition against the proliferation of human lung cancer A549 cells.

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.

GRP78 upregulation-induced increase in cisplatin sensitivity of SPCA1 lung cancer cells

Background Glucose regulated protein 78 （GRP78）, an endoplasmic reticulum （ER） chaperone, plays a critical role in chemotherapy resistance in a variety of cancers. In this study, we investigated the up-regulation of GRP78 induced by A23187 and its association with the chemotherapeutical sensibility to cisplatin in human lung cancer cell line SPCAI. Methods SPCA1 cells were pretreated with A23187 at different concentrations. The expression of GRP78 at the mRNA level was analyzed by RT-PCR; the expression of GRP78 at the protein level was determined by Western blotting and immunofluorescence assay. Cell survival was determined by MTT assay. Cell apoptosis was analyzed by flow cytometry. Results The expression of GRP78 at both the mRNA and protein levels was obviously induced by A23187 in SPCA1 cells, with an elevation of GRP78 by 2.1-fold at the mRNA level and by 3.8-fold at the protein level compared to the control. There was a dose-dependent response. Survival curve analysis demonstrated that A23187 induction caused a significant reduction of survival for the cells subjected to cisplatin treatment （P 〈0.05）. After treatment by cisplatin, the percentage of apoptotic cells in the A23187 pretreated group increased about three fold compared with the control group （（27.53!-4.32）% vs. （9.25＋3.64）%, P 〈0.05）. Conclusions A23187 treatment was fairly effective for the induction of GRP78 in SPCA1 cells at both the mRNA and protein levels. To a certain extent, GRP78 up-regulation by A23187 was associated with the enhancement of drug sensitivity to cisplatin in human luncl cancer cell line SPCAI.

Synergistic Cytotoxicity of Ampelopsin Sodium and Carboplatin in Human Non-Small Cell Lung Cancer Cell Line SPC-A1 by G1 Cell Cycle Arrested

Objective： To evaluate the cytotoxic effects of ampelopsin sodium（Amp-Na） and carboplatin（CBP） used alone or in combination on human non-small cell lung cancer（NSCLC） cells SPC-A1 in vitro and its related mechanism. Methods： Cytotoxic effects were assessed by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） assays. The synergistic effects of the drugs were calculated with coefficient of drug interaction（CDI）. Cell cycle was determined by flow cytometry（FCM）. The levels of p53, p21, cyclin E, cyclin D1, and phosphorylated cyclin-dependent kinase-2（p-CDK2） were evaluated by Western blot. Results： Amp-Na（6.25–200 μg/m L） and CBP（3.13–100 μg/m L） alone exhibited prominent cytotoxic activity in a concentration-dependent manner on SPC-A1 cells with 50% inhibitive concentration values of 57.07±14.46 and 34.97±6.30 μg/m L, respectively. Drug combinations were associated with significantly higher cytotoxic effects than each drug alone（P〈0.05 or 0.01）. The CDI analysis confirmed the synergy of Amp-Na and CBP on inhibiting cancer cell viability across a wide concentration range（CDI 〈1）. FCM and Western blot showed that synergistic cytotoxic effects of Amp-Na and CBP were related to G1 arrested which mainly mediated by p21 through the inhibition of CDK2 activity independent of the p53 tumor suppressor pathway. Conclusions： AmpNa exhibits anticancer activities and enhances the antitumor activities of CBP through up-regulation of p21 and inhibition of CDK2 activity in human NSCLC cells SPC-A1. These results suggest that Amp-Na may be applied to enhance the anticancer action of CBP.

XAF1 as a prognostic biomarker and therapeutic target in squamous cell lung cancer

Background X-linked inhibitor of apoptosis （XlAP）-associated factor 1 （XAF1） is a new tumor suppressor. Low expression of XAF1 is associated with poor prognosis of human cancers. However, the effect of XAF1 on lung cancer remains unknown. In this study, we investigated the expression of XAF1 and its role in squamous cell lung cancer. Methods Cancer tissues, cancer adjacent tissues and normal lung tissues were collected from 51 cases of squamous cell lung cancer. The expression of XAF1 mRNA was determined by reverse transcription-polymerase chain reaction （RT-PCR）. The expression of XAF1 protein was determined by Western blotting and immunohistochemical staining. Ad5/F35-XAF1 virus was generated. Cell proliferation and apoptosis were measured by 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT） method and flow cytometry （FACS）, respectively. Results The levels of XAF1 protein and mRNA in cancer tissues were significantly lower than those in cancer adjacent and normal lung tissues （P 〈0.05）. The low expression of XAF1 was associated with tumor grade, disease stage, differentiation status and lymph node metastasis in squamous cell lung cancer patients. The restoration of XAF1 expression mediated by Ad5/F35-XAF1 virus significantly inhibited cell proliferation and induced apoptosis in a dose- and time-dependent manner. Conclusion XAF1 is a valuable prognostic marker in squamous cell lung cancer and may be a potential candidate gene for lung cancer therapy.

Agglutinin isolated from Arisema heterophyllum Blume induces apoptosis and autophagy in A549 cells through inhibiting PI3K/Akt pathway and inducing ER stress

Arisaema heterophyllum Blume is one of the three medicinal plants known as traditional Chinese medicine Rhizoma Arisaematis(RA). RA has been popularly used to treat patients with convulsions, inflammation, and cancer for a long time. However, the underlying mechanisms for RA effects are still unclear. The present study was designed to determine the cytotoxicity of agglutinin isolated from Arisema heterophyllum Blume(AHA) and explore the possible mechanisms in human non-small-cell lung cancer A549 cells. AHA with purity up to 95% was isolated and purified from Arisaema heterophyllum Blume using hydrophobic interaction chromatography. AHA dose-dependently inhibited the proliferation of A549 cells and induced G_1 phase cell cycle arrest. AHA induced apoptosis by up-regulating pro-apoptotic Bax, decreasing anti-apoptotic Bcl-2, and activating caspase-9 and caspase-3. In A549 cells treated with AHA, the PI3K/Akt pathway was inhibited. Furthermore, AHA induced increase in the levels of ER stress markers such as phosphorylated eukaryotic initiation factor 2α(p-eIF2α), C/EBP-homologous protein(CHOP), inositol-requiring enzyme 1α(IRE1α), and phosphorylated c-Jun NH_2-terminal kinase(p-JNK). AHA also induced autophagy in A549 cells. Staining of acidic vesicular organelles(AVOs) and increase in the levels of LC3II and ATG7 were observed in AHA-treated cells. These findings suggested that AHA might be one of the active components with anti-cancer effects in Arisaema heterophyllum Blume. In conclusion, cytotoxicity of AHA on cancer cells might be related to its effects on apoptosis and autophagy through inhibition of PI3K/Akt pathway and induction of ER stress.