Gene Therapy For Lung Cancer Research Articles

Combined Local Pulmonary and Systemic Delivery of AT2R Gene by Modified TAT Peptide Nanoparticles Attenuates Both Murine and Human Lung Carcinoma Xenografts in Mice

To evaluate the potential of cell-penetrating peptide-based delivery of apoptosis-inducer gene in cancer therapy, a modified HIV-1 TAT peptide (dimerized TAT peptide, dTAT) was studied. The dTAT and plasmid DNA (pDNA) complexes (dTAT-pDNA) were condensed using calcium chloride (dTAT-pDNA-Ca2+). This simple nonviral formulation approach showed high levels of gene expression in vitro without any cytotoxicity. In mouse studies, a single intratracheal (IT) aerosol spray or 2 intravenous (IV) injections of the dTAT, apoptosis-inducer gene, angiotensin II type 2 receptor (AT2R), and Ca2+ complexes (dTAT-pAT2R-Ca2+) significantly attenuated the acutely growing mouse Lewis lung carcinoma allografts in mouse lungs. Furthermore, single IT (p = 0.054) and the combination of IT and IV (p < 0.05) administrations of dTAT-pAT2R-Ca2+ markedly attenuated slowly growing and relatively large-sized H358 human bronchioloalveolar carcinoma xenografts in mouse lungs. These results indicate that the dTAT-pDNA-Ca2+ effectively delivered the gene to cancer cells by either IT or IV administration although the local pulmonary delivery of the dTAT-pAT2R-Ca2+ showed more effective growth inhibition of orthotopic lung cancer grafts. Thus, the present study offers preclinical proof of concept that a dTAT-based nonviral gene delivery method via IT administration may be an effective lung cancer gene therapy.

The down-regulated ING5 expression in lung cancer: a potential target of gene therapy.

ING5 can interact with p53, thereby inhibiting cell growth and inducing apoptosis. We found that ING5 overexpression not only inhibited proliferation, migration, and invasion, but also induced G2 arrest, differentiation, autophagy, apoptosis, glycolysis and mitochondrial respiration in lung cancer cells. ING5 transfection up-regulated the expression of Cdc2, ATG13, ATG14, Beclin-1, LC-3B, AIF, cytochrome c, Akt1/2/3, ADFP, PFK-1 and PDPc, while down-regulated the expression of Bcl-2, XIAP, survivin,β-catenin and HXK1. ING5 transfection desensitized cells to the chemotherapy of MG132, paclitaxel, and SAHA, which paralleled with apoptotic alteration. ING5 overexpression suppressed the xenograft tumor growth by inhibiting proliferation and inducing apoptosis. ING5 expression level was significantly higher in normal tissue than that in lung cancer at both protein and mRNA levels. Nuclear ING5 expression was positively correlated with ki-67 expression and cytoplasmic ING5 expression. Cytoplasmic ING5 expression was positively associated with lymph node metastasis, and negatively with age, lymphatic invasion or CPP32 expression. ING5 expression was different in histological classification: squamous cell carcinoma > adenocarcinoma > large cell carcinoma > small cell carcinoma. Taken together, our data suggested that ING5 downregulation might involved in carcinogenesis, growth, and invasion of lung cancer and could be considered as a promising marker to gauge the aggressiveness of lung cancer. It might be employed as a potential target for gene therapy of lung cancer.

Apoptotic Effects of the B Subunit of Bacterial Cytolethal Distending Toxin on the A549 Lung Cancer Cell Line

Cytolethal distending toxin (CDT) is a secreted tripartite genotoxin produced by many pathogenic gram-negative bacteria. It is composed of three subunits, CdtA, CdtB and CdtC, and CdtB-associated deoxyribonuclease (DNase) activity is essential for the CDT toxicity. In the present study, to design a novel potentially antitumor drug against lung cancer, the possible mechanisms of cdtB anticancer properties were explored in the A549 human lung adenocarcinoma cell line. A recombinant plasmid pcDNA3.1/cdtB was constructed expressing CdtB of human periodontal bacterium Aggregatibacter actinomycetemcomitans and investigated for toxic properties in A549 cells and possible mechanisms. It was observed that plasmid pcDNA3.1/cdtB caused loss of cell viability, morphologic changes and induction of apoptosis. Furthermore, measurement of caspase activity indicated involvement of an intrinsic pathway of cell apoptosis. Consequently, the recombinant plasmid pcDNA3.1/cdtB may have potential as a new class of therapeutic agent for gene therapy of lung cancer.

Synthesis and application of poly(ethylene glycol)-co-poly(β-amino ester) copolymers for small cell lung cancer gene therapy

The design of polymeric nanoparticles for gene therapy requires engineering of polymer structure to overcome multiple barriers, including prolonged colloidal stability during formulation and application. Poly(β-amino ester)s (PBAEs) have been shown effective as polymeric vectors for intracellular DNA delivery, but limited studies have focused on polymer modifications to enhance the stability of PBAE/DNA polyplexes. We developed block copolymers consisting of PBAE oligomer center units and poly(ethylene glycol) (PEG) end units. We fabricated a library of PEG-PBAE polyplexes by blending PEGylated PBAEs of different PEG molecular weights and non-PEGylated PBAEs of different structures at various mass ratios of cationic polymer to anionic DNA. Non-PEGylated PBAE polyplexes aggregated following a 24h incubation in acidic and physiological buffers, presenting a challenge for therapeutic use. In contrast, among 36 PEG-PBAE polyplex formulations evaluated, certain polyplexes maintained a small size under these conditions. These selected polyplexes were further evaluated for transfection in human small cell lung cancer cells (H446) in the presence of serum, and the best formulation transfected ∼40% of these hard-to-transfect cells while preventing polymer-mediated cytotoxicity. When PEG-PBAE polyplex delivered Herpes simplex virus thymidine kinase plasmid in combination with the prodrug ganciclovir, the polyplexes killed significantly more H446 cancer cells (35%) compared to healthy human lung fibroblasts (IMR-90) (15%). These findings indicate that PEG-PBAE polyplexes can maintain particle stability without compromising their therapeutic function for intracellular delivery to human small cell lung cancer cells, demonstrate potential cancer specificity, and have potential as safe materials for small cell lung cancer gene therapy. Statement of SignificanceMany natural and synthetic biomaterials have been investigated as non-viral vectors to deliver nucleic acids for cancer therapy. However, there are multiple hurdles to successful transfection including achieving particle stability, efficient delivery to cancer cells, and low cytotoxicity. In particular, engineering the physicochemical surface properties of a nanoparticle to improve stability is often offset by a decrease in the cellular entry and transfection efficiency. We developed stable polymeric nanoparticles that demonstrate high transfection efficiency by modifying synthetic biodegradable cationic polymers and engineering nanoparticle formulations using a combinatorial approach. The results of this study show the potential of biodegradable surface-modified polymeric nanoparticles as clinically translatable, biomaterial-based vehicles for cancer gene therapy.

Expression of Chemokine XCL2 and CX3CL1 in Lung Cancer.

BackgroundChemokines are a family of small proteins secreted by cells with chemotactic activity, and they play important roles in cell adhesion. However, the expression of chemokine XCL2 and CX3CL1 in lung cancers in different pathological stages remains unclear.Material/MethodsXCL2 and CX3CL1 expression in lung cancers and adjacent non-cancerous tissues was detected by quantitative PCR and ELISA. The relative expression of both chemokines in lung cancers in different pathological stages was compared by immunohistochemical assay.ResultsThe relative expression level of XCL2 and CX3CL1 in lung cancer was significantly higher compared with adjacent normal tissues (P<0.001). The expression level of both chemokines was significantly increased with higher pathological stages, as indicated by immunohistochemical assay (P<0.05 or P <0.001). Their expression level in cancers with higher numbers of metastatic lymph nodes was also significantly increased compared with cancers with lower numbers of metastatic lymph nodes (P<0.05 or P<0.001).ConclusionsThe expression of XCL2 and CX3CL1 increases with increasing degree of malignancy, indicating that both chemokines might be important targets in gene therapy for lung cancer.

Correlation study of biological characteristics of non-small cell lung cancer A549 cells after transfecting plasmid by microbubble ultrasound contrast agent.

To explore the role of the abnormal expression of miRNAs in the development process of non-small cell lung cancer and the feasibility of ultrasound microbubble-mediated gene therapy after transfecting antisense miRNA-224 and miRNA-122a plasmids into non-small cell lung cancer A549 cells. Antisense miRNA-224 and miRNA-122a plasmids were transfected into non-small cell lung cancer A549 cells on the optimal ultrasound microbubble-mediated condition. We set up a control group. The cell proliferation activity, apoptosis, invasion ability were detected by MTT assay, Annexin V-PE, Transwell invasion experiment and colony formation assay, respectively. The expression of miRNA-224 decreased and the expression of miRNA-122a rose after the plasmids of target genes were transfected into non-small cell lung cancer A549 cells, and there were significant differences when compared with those of the control group (P<0.05). After the plasmids of target genes were transfected into A549 cells, the growth of antisense miRNA-224 and miRNA-122a were inhibited, and the differences were significant as compared with the control group (P<0.05). Besides, the inhibition of miRNA-122a group was the most significant and there was statistically significant difference as compared with miRNA-224 group (t=-4.694, P=0.009). After the plasmids of target genes were transfected into A549 cells, the proportion of apoptotic cells increased, the invasive cells were decreased and the clone ability reduced, and also there was a significant difference as compared with those of the control group (P<0.05). What's more, the apoptotic peak appeared in miRNA-122a group. Its invasion ability decreased most obviously (40.25±3.97/visual field), the number of clone ability was 104.93±4.87 and the inhibitory effect was the most obviously. There was statistically significant difference as compared with other groups (P<0.05). A549 cells transfected by ultrasound microbubble-mediated antisense miRNA-224 and miRNA-122a plasmids possessed good transfection efficiency. The cell growth, invasion and colony-forming abilities of transfected A549 cells were suppressed, which laid a solid foundation for the gene therapy of non-small cell lung cancer.

Combined RNAi targeting human Stat3 and ADAM9 as gene therapy for non-small cell lung cancer.

Previous studies have demonstrated that human signal transducer and activator of transcription 3 (Stat3) and disintegrin and metalloproteinase 9 (ADAM9) are promising targets for RNA interference (RNAi)-based gene therapy for human non-small cell lung cancer (NSCLC). Thus, in the present study, the recombinant lentiviral (Lv) small hairpin (sh)RNA expression plasmids Lv/sh-Stat3 and Lv/sh-ADAM9, which targeted Stat3 and ADAM9, respectively, were constructed and subsequently infected into the A549 human NSCLC cell line. Cell proliferation, migration, invasion and apoptosis were determined in vitro in A549 cells following treatment with Lv/sh-Stat3 or Lv/sh-ADAM9 alone or in combination. In addition, the combined effect of Lv/sh-Stat3 and Lv/sh-ADAM9 gene therapy was evaluated in vivo using A549 xenograft models in nude mice. The in vitro experiments demonstrated that A549 cells treated with a combination of Lv/sh-Stat3 and Lv/sh-ADAM9 exhibited a significant additive effect in their cell proliferation, migration, invasion and apoptosis abilities, compared with A549 cells treated with Lv/sh-Stat3 or Lv/sh-ADAM9 alone. The in vivo experiments conducted in A549 xenograft tumor mouse models revealed that the combined treatment with Lv/sh-Stat3 and Lv/sh-ADAM9 exerted an additive effect on tumor growth inhibition, compared with the treatment with Lv/sh-Stat3 or Lv/sh-ADAM9 alone. These results suggested that combined RNAi gene therapy targeting human Stat3 and ADAM9 may be a novel and promising strategy for the treatment of NSCLC.

DAL-1/4.1B contributes to epithelial-mesenchymal transition via regulation of transforming growth factor-β in lung cancer cell lines.

The present study aimed to investigate the effects of the tumor suppressor gene differentially expressed in adenocarcinoma of the lung 1 (DAL‑1)/4.1B on early‑stage adenocarcinoma of the lung. The role of DAL‑1/4.1B in the epithelial‑mesenchymal transition (EMT), which is implicated in cancer metastasis, was examined using DAL‑1 knockdown and overexpression, followed by polymerase chain reaction and western blot analysis of EMT markers, as well as cell counting and cell migration/invasion assays. The results showed that DAL‑1/4.1B has a role in transforming growth factor (TGF)‑β‑induced EMT in non‑small cell lung cancer cells. Silencing of DAL‑1/4.1B with inhibitory RNAs altered the expression of numerous EMT markers, including E‑cadherin and β‑catenin, whereas overexpression of DAL‑1/4.1B had the opposite effect. In addition, DAL‑1/4.1B expression was induced following TGF‑β treatment at the protein and mRNA level. DAL‑1/4.1B deficiency impaired TGF‑β‑induced EMT and increased cell migration and invasion. These results suggested that DAL‑1/4.1B contributed to the EMT and may be important for tumor metastasis in lung cancer. Together with the results of a previous study by our group, the present study suggested that DAL‑1/4.1B acts as a tumor suppressor in the early transformation process in lung cancer, while in later stages, it functions as an oncogene affecting the biological features of human lung carcinoma cells. The results of the present study provided evidence for the feasibility of utilizing DAL‑1/4.1B as a target for lung cancer gene therapy.

Construction of pVAX-WIF-1 Eukaryotic Expression Vector and Its Anti-tumor Effect on Lung Cancer

背景与目的WIF-1是肺癌中重要的抑癌基因之一，其编码蛋白WIF-1能够通过抑制Wnt/β-catenin信号通路达到抑制肿瘤生长增殖及促进凋亡等抗肺癌作用。本研究旨在利用美国食品和药品管理委员会认可用于临床治疗的pVAX载体，构建pVAX-WIF-1真核表达载体，初步探究pVAX-WIF-1在体内外对A549肺癌细胞的抗肿瘤作用。方法应用PCR方法扩增人WIF-1编码序列片段，构建pVAX-WIF-1载体后转染肺癌A549细胞，Western blot检测WIF-1基因的表达；采用MTT法、Hoechst3235染色和流式细胞术分别检测pVAX-WIF-1在体外对肺癌A549细胞增殖、凋亡作用的影响；构建A549小鼠皮下瘤模型，探究pVAX-WIF-1在体内的抗肺癌作用。结果真核表达质粒载体pVAX-WIF-1构建成功，pVAX-WIF-1转染A549细胞后，WIF-1蛋白表达升高。pVAX-WIF-1转染A549后能抑制细胞增殖和诱导凋亡。动物体内结果表明，pVAX-WIF-1能有效抑制肺癌肿瘤生长。结论本研究成功构建了pVAX-WIF-1真核表达质粒，pVAX-WIF-1能明显抑制A549肺癌细胞增殖和促进凋亡，有效抑制A549皮下瘤生长。本研究将为WIF-1基因的肺癌临床治疗奠定了基础。

Gene Therapy for Lung Cancer.

Gene therapy was originally conceived to treat monogenic diseases. The replacement of a defective gene with a functional gene can theoretically cure the disease. In cancer, multiple genetic defects are present and the molecular profile changes during the course of the disease, making the replacement of all defective genes impossible. To overcome these difficulties, various gene therapy strategies have been adopted, including immune stimulation, transfer of suicide genes, inhibition of driver oncogenes, replacement of tumor-suppressor genes that could mediate apoptosis or anti-angiogenesis, and transfer of genes that enhance conventional treatments such as radiotherapy and chemotherapy. Some of these strategies have been tested successfully in non-small-cell lung cancer patients and the results of laboratory studies and clinical trials are reviewed herein.

Human non-small cell lung cancer expresses putative cancer stem cell markers and exhibits the transcriptomic profile of multipotent cells.

BackgroundDespite significant advances in staging and therapies, lung cancer remains a major cause of cancer-related lethality due to its high incidence and recurrence. Clearly, a novel approach is required to develop new therapies to treat this devastating disease. Recent evidence indicates that tumours contain a small population of cells known as cancer stem cells (CSCs) that are responsible for tumour maintenance, spreading and resistant to chemotherapy. The genetic composition of CSCs so far is not fully understood, but manipulation of the specific genes that maintain their integrity would be beneficial for developing strategies to combat cancer. Therefore, the goal of this study isto identify the transcriptomic composition and biological functions of CSCs from non-small cell lung cancer (NSCLC).MethodsWe isolated putative lung CSCs from lung adenocarcinoma cells (A549 and H2170) and normal stem cells from normal bronchial epithelial cells (PHBEC) on the basis of positive expression of stem cell surface markers (CD166, CD44, and EpCAM) using fluorescence-activated cell sorting. The isolated cells were then characterised for their self-renewal characteristics, differentiation capabilities, expression of stem cell transcription factor and in vivo tumouregenicity. The transcriptomic profiles of putative lung CSCs then were obtained using microarray analysis. Significantly regulated genes (p < 0.05, fold change (FC) > 2.0) in putative CSCs were identified and further analysed for their biological functions using the Database for Annotation, Visualization, and Integrated Discovery (DAVID).ResultsThe putative lung CSCs phenotypes of CD166+/CD44+ and CD166+/EpCAM+ showed multipotent characteristics of stem cells, including the ability to differentiate into adipogenic and osteogenic cells, self-renewal, and expression of stem cell transcription factors such as Sox2 and Oct3/4. Moreover, the cells also shows the in vivo tumouregenicity characteristic when transplanted into nude mice. Microarray and bioinformatics data analyses revealed that the putative lung CSCs have molecular signatures of both normal and cancer stem cells and that the most prominent biological functions are associated with angiogenesis, migration, pro-apoptosis and anti-apoptosis, osteoblast differentiation, mesenchymal cell differentiation, and mesenchyme development. Additionally, self-renewal pathways such as the Wnt and hedgehog signalling pathways, cancer pathways, and extracellular matrix (ECM)-receptor interaction pathways are significantly associated with the putative lung CSCs.ConclusionThis study revealed that isolated lung CSCs exhibit the characteristics of multipotent stem cells and that their genetic composition might be valuable for future gene and stem cells therapy for lung cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1086-3) contains supplementary material, which is available to authorized users.

A silica–polymer composite nano system for tumor-targeted imaging and p53 gene therapy of lung cancer

In our study, a silica–polymer composite nano system (MB-NSi–p53–CS ternary complexes) composed of methylene blue-encapsulated amine-terminated silica nanoparticles (MB-NSi) and chondroitin sulfate (CS) were successfully developed for tumor-targeted imaging and p53 gene therapy of lung cancer. MB was employed as a NIR probe for in vivo imaging, MB-NSi nanoparticles were served as gene vector, while CS was applied to be a coating and targeting polymer. MB-NSi–p53–CS ternary complexes displayed nanosized diameter, effective p53 condensation ability, efficient p53 protection profile, and superior bovine serum albumin stability in vitro. Experiments on A549 cell line further revealed low cytotoxicity, high p53 transfection, and anticancer efficacy of MB-NSi–p53–CS ternary complexes. In vivo imaging and tumor targetability assays demonstrated that MB-NSi–p53–CS ternary complexes were a preferable system with desirable imaging and tumor-targeting properties.

Epidermal growth factor activates telomerase activity by direct binding of Ets-2 to hTERT promoter in lung cancer cells.

Growth signals are directly or indirectly involved in telomerase regulation. In this study, we investigated molecular mechanisms of the effect of EGF (epidermal growth factor) on regulating hTERT (human telomerase reverse transcriptase) expression. To elucidate specific transcription factors involved in EGF-stimulated hTERT transcription in A549 and H1299 lung cancer cells, transcription factors drives hTERT promoter activity, such as Myc, Mad, and Ets-2, was evaluated on luciferase reporter assay. The upregulation of hTERT promoter by Ets-2 and Myc were abolished by Mad. Using DAPA (DNA affinity precipitation assay), Ets-2 binding to SNP (T) was stronger than Ets-2 binding to SNP (C) at -245 bp upstream of the transcription start site within the core promoter of hTERT. Ets-2 silence by siRNA decreased hTERT expression at mRNA and protein levels. The regulation of hTERT promoter by EGF/Ets-2 was diminished via the EGFR kinase signal pathway-specific inhibitors AG1478 and Iressa. Inhibitors of Erk and Akt inhibited Ets-2-activated hTERT promoter activity. These data suggested that Ets-2, a genuine cancer-specific transcription factor, is actively involved in EGFR kinase-induced hTERT overexpression pathway in lung cancer cells. Blockage of this pathway may contribute to targeted gene therapy in lung cancer.

Nanostructured lipid carriers as novel drug delivery system for lung cancer gene therapy

Context: Nanostructured lipid carriers (NLC) are potentially good colloidal drug carriers for gene delivery. They are advised to be the second lifetime of lipid nanocarriers.Objective: The aim of this study is to develop novel modified NLC as nanomedicine for delivery of plasmid-containing enhanced green fluorescence protein (pEGFP). This system could target the lung cancer cells through receptor-mediated pathways to increase the nuclear uptake of genetic materials.Methods: In the present study, pEGFP-loaded NLC (NLC/pEGFP) were prepared. Transferrin (Tf) containing ligands were used for the surface coating of the vectors. In vitro transfection efficiency of the modified vectors was evaluated in human alveolar adenocarcinoma cell line (A549 cells) and in vivo transfection efficiency of the modified vectors was evaluated on mice bearing A549 cells model.Results: Tf-modified NLC/pEGFP (Tf-NLC/pEGFP) has a particle size of 157 nm, and ∼82% of gene loading quantity. Tf-NLC/pEGFP displayed remarkably higher transfection efficiency than non-modified NLC/pEGFP both in vitro and in vivo.Conclusion: The results demonstrate that the novel NLC gene delivery system offers an effective strategy for lung cancer gene therapy.

A novel potential biocompatible hyperbranched polyspermine for efficient lung cancer gene therapy

The clinical successful application of gene therapy critically depends upon the development of non-toxic and efficient delivery system. Although polycationic non-viral vectors hold great promise in nanomedicine, the exploring of application in clinics still remains a big challenge. To develop a non-toxic and efficient non-viral gene delivery system, two kinds of endogenous substance, citric acid (CA) and spermine (SPE), were used to prepare a new low charge density hyperbranched polyspermine (HPSPE) by one-pot polymerization. The biocompatibility evaluated by hemolytic activity and red blood cell (RBC) aggregation indicated that HPSPE was highly biocompatible without causing hemolysis and RBC aggregation compared with PEI as well as SPE. The MTS assay also demonstrated that the cell viability of HPSPE was above 90% even at 200μg/mL at different time (24 and 72h), which much higher than PEI 25K. Besides, HPSPE showed high transfection efficiency without any toxic effect after aerosol delivery to the mice. Moreover, aerosol delivery of HPSPE/Akt1 shRNA significantly reduced tumor size and numbers and efficiently suppressed lung tumorigenesis ultimately in K-rasLA1 lung cancer model mice. These results suggest that low charge density as well as endogenous substance skeleton endow HPSPE with great potential for toxicity-free and efficient gene therapy.

Aerosol delivery of programmed cell death protein 4 using polysorbitol-based gene delivery system for lung cancer therapy

The development of a safe and effective gene delivery system is the most challenging obstacle to the broad application of gene therapy in the clinic. In this study, we report the development of a polysorbitol-based gene delivery system as an alternative gene carrier for lung cancer therapy. The copolymer was prepared by a Michael addition reaction between sorbitol diacrylate (SD) and spermine (SPE); the SD–SPE copolymer effectively condenses with DNA on the nanoscale and protects it from nucleases. SD–SPE/DNA complexes showed excellent transfection with low toxicity both in vitro and in vivo, and aerosol delivery of SD-SPE complexes with programmed cell death protein 4 DNA significantly suppressed lung tumorigenesis in K-rasLA1 lung cancer model mice. These results demonstrate that SD–SPE has great potential as a gene delivery system based on its excellent biocompatibility and high gene delivery efficiency for lung cancer gene therapy.

Co-delivery of plasmid DNA and doxorubicin by solid lipid nanoparticles for lung cancer therapy.

The co-delivery of DNA and antitumor drugs has the potential to treat cancer. In this study, we aimed to develop surface-modified, co-encapsulated solid lipid nanoparticles (SLN) containing enhanced green fluorescence protein plasmid (pEGFP) and doxorubicin (DOX) in order to create a multifunctional delivery system that targets lung cancer cells, in an effort to improve the efficacy of cancer therapy. DOX- and pEGFP-loaded SLN were prepared separately and then mixed to form co-encapsulated SLN (SLN/DE). Transferrin (Tf)-containing ligands were used for the surface coating of the vectors. The in vitro transfection efficiency of the modified vectors was evaluated using a human alveolar adenocarcinoma cell line (A549 cells) and the in vivo transfection efficiency of the modified vectors was evaluated using mice bearing A549 tumors. The Tf-modified DOX and pEGFP co-encapsulated SLN (T-SLN/DE) had a particle size of 267 nm with a 42 mV surface charge. The in vitro cytotoxicity of T-SLN/DE was low (cell viability was between 80 and 100% compared with the controls). T-SLN/DE displayed a remarkable therapeutic effect both in drug delivery and gene therapy. In conclusion, our results demonstrate that the multifunctional delivery system can improve the efficacy of cancer therapy through the combination of gene therapy and chemotherapy. In addition, the coating of active targeting ligands can improve the efficacy of the carriers at targeting lung cancer cells. Thus, the novel gene and drug delivery system offers an effective strategy for lung cancer gene therapy.

OP0021 Non-small-cell lung cancer exhibits multipotent characteristics of stem cells

Background Lung cancer remains a major cause of cancer-related death because of the high incidence and recurrence despite significant advances in staging and therapies. Recent evidence indicates that tumours contain a small population of cells known as cancer stem cells (CSCs) that are responsible for tumour maintenance and spreading and are resistant to chemotherapy. The genetic composition of CSCs is yet to be fully understood and manipulation of the specific gene that maintains their integrity would be beneficial for future strategies to combat cancer. Methods In the current study, we isolated putative lung CSCs from a lung adenocarcinoma cell line (A549) and normal stem cells from normal bronchial epithelial cells (PHBEC) on the basis of positive expression of stem cell surface markers (CD166, CD44 and EpCAM) using fluorescence-activated cell sorting. Findings The putative lung CSC phenotypes of CD166+CD44+ and CD166+EpCAM+ showed multipotent characteristics of stem cells, including the capability to differentiate into osteogenic and chondrogenic, self-renewal, and expression of stem cell transcription factors such as Sox2, Oct3/4, and Klf4. Microarray and bioinformatics data analyses revealed that the putative lung CSCs have molecular signatures for both normal and cancer stem cells with most prominent biological functions associated with angiogenesis, migration, proapoptotic and antiapoptotic osteoblast differentiation, mesenchymal cell differentiation, and mesenchyme development. Additionally, self-renewal pathways such as Wnt and Hedgehog signalling pathways, pathways in cancer, apoptosis, p53, and the ECM-receptor interaction pathway are also significantly associated with the putative CSCs. Interpretation The study revealed that isolated lung CSCs exhibit the characteristics of multipotent stem cells and their genetic composition might be valuable for future gene and stem cell therapy for lung cancer.

Gene Therapy of Lung Adenocarcinoma using Herpes Virus Expressing a Fusogenic Membrane Glycoprotein

The aim of this study is to observe the in vitro-targeted destruction of lung adenocarcinoma using recombinant Type I herpes simplex virus (HSV-I)-mediated gibbon ape leukemia virus envelope glycoprotein (GALV.fus), controlled by UL38 promoter and cytomegalovirus promoter (CMVP). A recombinant HSV-I plasmid encoding the GALV.fus was transfected into green monkey kidney cells, the lung adenocarcinoma line A549, and the human fetal fibroblast cell line HFL-I GNHu5 in various doses. The effects and expression of in vitro GALV.fus were observed using an inverted microscope. Enhanced green fluorescence protein expression served as the contro1 for GALV.fus. Recombinant HSV-I virus was produced. Fusogenic recombinant virus infection led to cell fusions in A549 in a dose-dependent manner. Nonfusogenic viruses only produced conventional cytotoxic effects. Recombinant HSV-I with the CMVP initiated cell fusions in HFL-1 GNHu5 cells with arrested cell cycles or as quiescence. HSV-I regulated by UL38p caused cell fusion only in growing cells. Protein expression of GALV.fus was confirmed by Western Blot in infected A549 and HFL-1 GNHu5. Delivery and tumor-specific expression of GALV.fus gene can selectively and safely target lung cancer in vitro, and may prove to be a novel gene therapy for lung cancer.

Spermine‐alt‐poly(ethylene glycol) polyspermine as a safe and efficient aerosol gene carrier for lung cancer therapy

The clinical success of gene therapy critically depends upon the safety and efficiency of delivery system used. Although polyethylenimine (PEI) has been commonly used as an efficient cationic polymeric gene carrier due to its high transfection efficiency, its cytotoxicity and nondegradability limit the polymer's therapeutic applications in clinical trials. In this study, biocompatible polyspermine based on spermine (SPE) and poly(ethylene glycol) (PEG) diacrylate (SPE-alt-PEG) was synthesized using a Michael-type addition reaction, and its ability as an alternative gene carrier for lung cancer therapy was evaluated. SPE-alt-PEG polyspermine was complexed with plasmid DNA, and the resulting complexes were characterized by particle size and surface charge by dynamic light scattering, complex formation and DNA protection ability by gel retardation, and complex shape by energy-filtering transmission electron microscopy. The SPE-alt-PEG copolymer showed low cytotoxicity, and SPE-alt-PEG/DNA complexes showed efficacious transfection efficiency compared with 25 kDa PEI (PEI 25K). Also SPE-alt-PEG/GFP complexes were efficiently transferred into the lungs after aerosol administration without toxicity, and delivery of Pdcd4 gene as a therapeutic gene with SPE-alt-PEG polyspermine greatly reduced tumor size as well as tumor numbers in K-ras(LA1) lung cancer model mice compared relative to the effect observed for PEI 25K. These results suggest that SPE-alt-PEG has potential as a gene carrier for lung cancer gene therapy.