Search

Protein-protein interactions featuring intricate binding epitopes remain challenging targets for synthetic inhibitors. Interactions of NEMO, a scaffolding protein central to NF-κB signaling, exemplify this challenge. Various regulators are known to interact with different coiled coil regions of NEMO, but the topological complexity of this protein has limited inhibitor design. We undertook a comprehensive effort to block the interaction between vFLIP, a Kaposi’s sarcoma herpesviral oncoprotein, and NEMO using small molecule screening and rational design. Our efforts reveal that a tertiary protein structure mimic of NEMO is necessary for potent inhibition. The rationally designed mimic engages vFLIP directly causing complex disruption, protein degradation and suppression of NF-κB signaling in primary effusion lymphoma (PEL). NEMO mimic treatment induces cell death and delays tumor growth in a PEL xenograft model. Our studies with this inhibitor reveal the critical nexus of signaling complex stability in the regulation of NF-κB by a viral oncoprotein., NF-κB signalling involves the scaffold protein NEMO, which can be bound by the oncoprotein vFLIP to promote cell survival and oncogenic transformation. Here the authors rationally engineer a tertiary protein mimic of NEMO to disrupt the vFLIP-NEMO interaction to induce cell death.

// Seong-Ho Hong 1, 2 , Seung-Hee Chang 1 , Kyung-Cho Cho 3 , Sanghwa Kim 1, 4 , Sungjin Park 1 , Ah Young Lee 1 , Hu-Lin Jiang 5 , Hyeon-Jeong Kim 1 , Somin Lee 1, 4 , Kyeong-Nam Yu 1 , Hwi Won Seo 6 , Chanhee Chae 6 , Kwang Pyo Kim 3 , Jongsun Park 7 , Myung-Haing Cho 1, 4, 8, 9, 10 1 Laboratory of Toxicology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea 2 New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea 3 Department of Applied Chemistry, College of Applied Science, Kyung Hee University, Yongin 17104, Korea 4 Graduate Group of Tumor Biology, Seoul National University, Seoul 08826, Korea 5 Department of Pharmaceutics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China 6 Laboratory of Pathology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea 7 Department of Pharmacology and Medical Science, Infection Signaling Network Research Center, College of Medicine, Chungnam National University, Daejeon 35015, Korea 8 Graduate School of Convergence Science and Technology, Seoul National University, Suwon 16229, Korea 9 Advanced Institute of Convergence Technology, Seoul National University, Suwon 16229, Korea 10 Institute of GreenBio Science Technology, Seoul National University, Pyeongchang-gun 25354, Korea Correspondence to: Myung-Haing Cho, email: mchotox@snu.ac.kr Jongsun Park, email: insulin@cnu.ac.kr Keywords: lung cancer, gene therapy, endoplasmic reticulum-Golgi intermediate compartment protein 3 (ERGIC3), golgi apparatus, ER stress Received: February 01, 2016 Accepted: August 08, 2016 Published: August 29, 2016 ABSTRACT Trafficking from the endoplasmic reticulum (ER) to the Golgi apparatus is elevated in cancer cells. Therefore, proteins of the ER-Golgi intermediate compartment (ERGIC) attract significant attention as targets for cancer treatment. Enhanced cancer cell growth and epithelial-mesenchymal transition by ERGICs correlates with poor-prognosis of lung cancer. This prompted us to assess whether knockdown of ERGIC3 may decrease lung cancer growth. To test the hypothesis, the effects of ERGIC3 short hairpin RNA (shERGIC3) on ER stress-induced cell death and lung tumorigenesis were investigated both in vitro and in vivo . Knockdown of ERGIC3 led to ER stress-induced autophagic cell death and suppression of proliferation in the A549 human lung cancer cell-line. Moreover, non-invasive aerosol-delivery of shERGIC3 using the biocompatible carrier glycerol propoxylate triacrylate and spermine (GPT-SPE) inhibited lung tumorigenesis in the K-ras LA1 murine model of lung cancer. Our data suggest that suppression of ERGIC3 could provide a framework for the development of effective lung cancer therapies.

Inorganic phosphate (Pi) plays crucial roles in several biological processes and signaling pathways. Pi uptake is regulated by sodium-dependent phosphate (Na/Pi) transporters (NPTs). Moreover, Pi is used as a food additive in food items such as sausages, crackers, dairy products, and beverages. However, the high serum concentration of phosphate (> 5.5 mg/dL) can cause adverse renal effects, cardiovascular effects including vascular or valvular calcification, and stimulate bone resorption. In addition, Pi can also alter vital cellular signaling, related to cell growth and cap-dependent protein translation. Moreover, intake of dietary Pi, whether high (1.0%) or low (0.1%), affects organs in developing mice, and is related to tumorigenesis in mice. The recommended dietary allowance (RDA) of Pi is the daily dietary intake required to maintain levels above the lower limit of the range of normal serum Pi concentration (2.7 mg/dL) for most individuals (97-98%). Thus, adequate intake of Pi (RDA; 700 mg/day) and maintenance of normal Pi concentration (2.7-4.5 mg/dL) are important for health and prevention of diseases caused by inadequate Pi intake.

A large amount of fructose intake along with smoking is associated with increased incidence of diseases linked to metabolic syndrome. More research is necessary to understand the complex mechanism that ultimately results in metabolic syndrome and the effect, if any, of high fructose dietary intake and smoking on individual health. In this study, we investigated changes in ER-Golgi network and disturbance to secretion of adipokines induced by cigarette smoking (CS) and excess fructose intake and their contribution to the disruption of metabolic homeostasis. We used high fructose-induced metabolic disorder mice model by feeding them with high fructose diet for 8 weeks. For CS exposure experiment, these mice were exposed to CS for 28 days according to OECD guideline 412. Our results clearly showed that the immune system was suppressed and ER stress was induced in mice with exposure to CS and fed with high fructose. Furthermore, their concentrations of adipokines including leptin and adiponectin were aberrant. Such alteration in secretion of adipokines could cause insulin resistance which may lead to the development of type 2 diabetes.

Achievement of long-term survival of patients with lung cancer treated with conventional chemotherapy is still difficult for treatment of metastatic and advanced tumors. Despite recent progress in investigational therapies, survival rates are still disappointingly low and novel adjuvant and systemic therapies are urgently needed. A recently elucidated secretory pathway is attracting considerable interest as a promising anticancer target. The cis-Golgi matrix protein, GOLGA2/GM130, plays an important role in glycosylation and transport of protein in the secretory pathway. In this study, the effects of short hairpin RNA (shRNA) constructs targeting GOLGA2/GM130 (shGOLGA2) on autophagy and lung cancer growth were evaluated in vitro and in vivo. Downregulation of GOLGA2/GM130 led to induction of autophagy and inhibition of glycosylation in A549 cells and in the lungs of K-ras(LA1) mice. Furthermore, downregulation of GOLGA2/GM130 decreased angiogenesis and cancer cell invasion in vitro and suppressed tumorigenesis in lung cancer mice model. The tumor specificity of sequence targeting GOLGA2/GM130 was also demonstrated. Taken together, these results suggest that induction of autophagy by shGOLGA2 may induce cell death rather than cell survival. Therefore, downregulation of GOLGA2/GM130 may be a potential therapeutic option for lung cancer.

Osteopontin (OPN) is a secreted glycophosphoprotein that has been implicated in the regulation of cancer development. The function of OPN is primarily regulated through post-translational modification such as glycosylation. As yet, however, the relationship between OPN glycosylation and lung cancer development has not been investigated. In this study, we addressed this issue by studying the effect of a triple mutant (TM) of OPN, which is mutated at three O-glycosylation sites, on lung cancer development in K-ras (LA1) mice, a murine model for human non-small cell lung cancer.Aerosolized lentivirus-based OPN TM was delivered into the lungs of K-ras (LA1) mice using a nose-only-inhalation chamber 3 times/wk for 4 wks. Subsequently, the effects of repeated delivery of OPN TM on lung tumorigenesis and its concomitant OPN-mediated signaling pathways were investigated.Aerosol-delivered OPN TM inhibited lung tumorigenesis. In addition, the OPN-mediated Akt signaling pathway was inhibited. OPN TM also decreased NF-κB activity and the phosphorylation of 4E-BP1, while facilitating apoptosis in the lungs of K-ras (LA1) mice.Our results show that aerosol delivery of OPN TM successfully suppresses lung cancer development in the K-ras (LA1) mouse model and, therefore, warrant its further investigation as a possible therapeutic strategy for non-small cell lung cancer.

Polyethyleneimine (PEI) has been described as a highly efficient gene carrier due to its efficient proton sponge effect within endosomes. However, many studies have demonstrated that PEI is toxic and associated with a lack of cell specificity despite high transfection efficiency. In order to minimize the toxicity of PEI, we prepared chitosan-graft-spermine (CHI-g-SPE) in a previous study. CHI-g-SPE showed low toxicity and high transfection efficiency. However, this compound also had limited target cell specificity. In the present study, we synthesized galactosylated CHI-g-SPE (GCS) because this modified GCS could be delivered specifically into the liver due to hepatocyte-specific galactose receptors. The DNA-binding properties of GCS at various copolymer/DNA weight ratios were evaluated by a gel retardation assay. The GCS copolymer exhibited significant DNA-binding ability and efficiently protected DNA from nuclease attack. Using energy-filtered transmission electron microscopy (EF-TEM), we observed dense spherical, nano-sized GCS/DNA complexes with a homogenous distribution. Most importantly, GCS was associated with remarkably low cytotoxicity compared to PEI in HepG2, HeLa, and A549 cells. Moreover, GCS carriers specifically delivered the gene-of-interest into hepatocytes in vitro as well as in vivo. Our results suggest that the novel GCS described here is a safe and highly efficient carrier for hepatocyte-targeted gene delivery.

Seong-Ho Hong1,*, Ji-Eun Kim1,6,*, You-Kyoung Kim2, Arash Minai-Tehrani1, Ji-Young Shin1, Bitna Kang1, Hye-Joon Kim1, Chong-Su Cho2, Chanhee Chae3, Hu-Lin Jiang1, Myung-Haing Cho1,4–71Laboratory of Toxicology, 2Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, 3Laboratory of Pathology, College of Veterinary Medicine, 4Graduate Group of Tumor Biology, 5Center for Food and Toxicology, Seoul National University, Seoul, Korea; 6Department of Nano Fusion Technology, Graduate School of Convergence Science and Technology, 7Advanced Institute of Convergence Technology, Seoul National University, Suwon, Korea*These authors contributed equally to this workBackground: Polyethylenimine (PEI)-based nonviral gene-delivery systems are commonly employed because of their high transfection efficiency. However, the toxic nature of PEI is a significant obstacle in clinical gene therapy. In this study, we developed biocompatible glycerol triacrylate–spermine (GT–SPE) polyspermine as a nanosized gene carrier for potential lung cancer gene therapy.Methods: The GT–SPE was synthesized using the Michael addition reaction between GT and SPE. The molecular weight was characterized using gel permeability chromatography multiangle laser light scattering and the composition of the polymer was analyzed using proton nuclear magnetic resonance.Results: The GT–SPE successfully protected the DNA from nucleases. The average particle size of the GT–SPE was 121 nm with a zeta potential of +23.45 mV. The GT–SPE was found to be less toxic than PEI for various cell lines, as well as for a murine model. Finally, our results showed that the GT–SPE/small hairpin Akt1 (shAkt1) complex suppressed lung tumorigenesis in a K-rasLA1 lung cancer mice model by inducing apoptosis through the Akt signaling pathway and cell cycle arrest. Aerosol delivered GT–SPE/shAkt1, which reduced matrix metalloproteinase-9 activity and suppressed the expression levels of proliferating cell nuclear antigen, as well as vascular endothelial growth factors and CD31, which are known proliferation and angiogenesis markers, respectively.Conclusion: Our data suggest that GT–SPE may be a candidate for short hairpin-shaped RNA-based aerosol lung cancer gene therapy.Keywords: lung cancer, gene therapy, aerosol delivery, spermineCorrigendum has been published for this paper.

Non-viral gene delivery systems based on polyethyleneimine (PEI) are efficient due to their proton-sponge effect within endosomes, but they have poor physical characteristics such as slow dissociation, cytotoxicity, and non targeted gene delivery. To overcome many of the problems associated with PEI, we synthesized a galactosylated poly(ethylene glycol)-chitosan-graft-spermine (GPCS) copolymer with low cytotoxicity and optimal gene delivery to hepatocytes using an amide bond between galactosylated poly(ethylene glycol) and chitosan-graft-spermine. The GPCS copolymer formed complexes with plasmid DNA, and the GPCS/DNA complexes had well-formed spherical shapes. The GPCS/DNA complexes were nanoscale size with homogenous size distribution and a positive zeta potential by dynamic light scattering (DLS). The GPCS copolymer had lower cytotoxicity than that of PEI 25K in HepG2, HeLa, and A549 cell lines at various concentrations and showed good hepatocyte-targeting ability. Furthermore, GPCS/DNA complexes showed higher levels of GFP expression in the liver in model mice after intravenous injection than naked DNA and metoxy-poly(ethylene glycol)-chitosan-graft-spermine as controls without remarkable fibrosis, inflammation, lipidosis, or necrosis. In a tumor suppression study, an intravenous injection of the GPCS/Pdcd4 complexes significantly suppressed tumor growth, activated apoptosis, and suppressed proliferation and angiogenesis in liver tumor-bearing H-ras12V mice. Our results indicate that the GPCS copolymer has potential as a hepatocyte-targeting gene carrier.

Lung cancer has the highest mortality rate among cancers and current therapies are not efficient. Therefore, novel therapeutic methods are urgently needed. Here, we examined the effectiveness of simultaneous Akt1 inhibition and Pdcd4 over-expression using a dual expression system in suppressing tumorigenesis in K-ras(LA1) mice (a lung cancer model).An shRNA targeting Akt1 (shAkt1) and cDNA of programmed cell death protein 4 (Pdcd4) were inserted into a dual expression vector (shAkt1+Pdcd4). A sorbitol diacrylate-polyethylenimine (SDA-PEI) carrier was used because of low toxicity and high transfection efficiency. Aerosolized SDA-PEI/shAkt1+Pdcd4 complex was delivered to the mice twice a week for 4 weeks using a nose-only exposure inhalation chamber.Simultaneous Akt1 inhibition and Pdcd4 over-expression synergistically induced potent antitumor effect. Analysis revealed significant reduction in lung tumor number.Dual expression of shAkt1 and Pdcd4 effectively suppresses lung tumorigenesis.

Atopic dermatitis, one of the most important skin diseases, is characterized by both skin barrier impairment and immunological abnormalities. Although several studies have demonstrated the significant relationship between atopic dermatitis and immunological abnormalities, the role of hydroxyeicosatetraenoic acids (HETE) in atopic dermatitis remains unknown. To develop chiral methods for characterization of 12-HETE enantiomers in a 1-chloro-2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis mouse model and evaluate the effects of 12-HETE on atopic dermatitis, BALB/c mice were treated with either DNCB or acetone/olive oil (AOO) to induce atopic dermatitis, after which 12(R)- and 12(S)-HETEs in the plasma, skin, spleen, and lymph nodes were quantified by chiral liquid chromatography-tandem mass spectrometry. 12(R)- and 12(S)-HETEs in biological samples of DNCB-induced atopic dermatitis mice increased significantly compared with the AOO group, reflecting the involvement of 12(R)- and 12(S)-HETEs in atopic dermatitis. These findings indicate that 12(R)- and 12(S)-HETEs could be a useful guide for understanding the pathogenesis of atopic dermatitis.

© 2015 Lee et al. Inorganic phosphate (Pi) is required by all living organisms for the development of organs such as bone, muscle, brain, and lungs, regulating the expression of several critical genes as well as signal transduction. However, little is known about the effects of prolonged dietary Pi consumption on lung cancer progression. This study investigated the effects of a highphosphate diet (HPD) in a mouse model of adenocarcinoma. K-rasLA1 mice were fed a normal diet (0.3% Pi) or an HPD (1% Pi) for 1, 2, or 4 months. Mice were then sacrificed and subjected to inductively coupled plasma mass/optical emission spectrometry and laser ablation inductively coupled plasma mass-spectrometry analyses, western blot analysis, histopathological, immunohistochemical, and immunocytochemical analyses to evaluate tumor formation and progression (including cell proliferation, angiogenesis, and apoptosis), changes in ion levels and metabolism, autophagy, epithelial-to-mesenchymal transition, and protein translation in the lungs. An HPD accelerated tumorigenesis, as evidenced by increased adenoma and adenocarcinoma rates as well as tumor size. However, after 4 months of the HPD, cell proliferation was arrested, and marked increases in liver and lung ion levels and in energy production via the tricarboxylic acid cycle in the liver were observed, which were accompanied by increased autophagy and decreased angiogenesis and apoptosis. These results indicate that an HPD initially promotes but later inhibits lung cancer progression because of metabolic adaptation leading to tumor cell quiescence. Moreover, the results suggest that carefully regulated Pi consumption are effective in lung cancer prevention.

Murine rheumatoid arthritis models are often used to investigate the potential therapeutic effects of candidate drugs. The present study has been conducted in order to investigate the therapeutic efficacy of ascidian tunicate extracts in a collagen-induced arthritis DBA1/J mice model. Four types of formulas, ascidian tunicate extracts (ATE), crude ascidian tunicate glycans (ATEC), ascidian tunicate extracts with licorice extracts (ATEL), and crude ascidian tunicate glycans with licorice extracts (ATECL) were orally administered into DBA/1J mice for 3 weeks and paw edema and thickness were evaluated. Changes in inflammatory proteins and cytokines levels were monitored in hind leg tissues by Western blot and quantitative PCR analysis. The oral administration of ascidian tunicate extracts alleviated paw edema and improved the histological hind leg cartilage status. The extracts also reduced the matrix metalloproteinase-9 (MMP-9) protein and prostaglandin E synthase (PGES) levels. In addition, the extracts-treated groups showed increased interleukin-10 (IL-10) levels compared with the non-treated group. These findings suggest that orally administered ascidian tunicate extracts might have potential therapeutic effects for the treatment of rheumatoid arthritis.

Broussonetia papyrifera (L.) Vent. and Lonicera japonica Thunb. have been used in recent medicinal research for their antioxidative and anti-inflammatory properties. The present study investigated the therapeutic efficacy of B. papyrifera and L. japonica ethanolic extracts in a murine model of ovalbumin-induced asthma, in which intra-peritoneal (IP) injections and aerosol ovalbumin delivery were used to induce allergic asthma. Bronchioalveolar lavage fluid (BALF), serum samples, lungs and livers were collected from the experimental groups. In the groups treated with B. papyrifera and L. japonica extracts, CD3, CD4, serum IgE and IL-4 levels; activities of matrix metalloproteinase (MMP)-2 and MMP-9; and eotaxin levels in the BALF significantly decreased to near normal levels. Results of a histopathological analysis showed that the level of inflammation and mucous secretions reduced in the treated groups compared to the corresponding levels in the other groups. Moreover, results of a serum enzymatic analysis showed the non-toxic nature of the extracts in the B. papyrifera and L. japonica treated groups. Taken together, these results clearly indicate that the B. papyrifera and L. japonica extracts may be very effective against asthma and inflammation related diseases.

The sodium-dependent phosphate co-transporter 2b (NPT2b) plays an important role in maintaining phosphate homeostasis. In previous studies, we have shown that high dietary inorganic phosphate (Pi) consumption in mice stimulated lung tumorigenesis and increased NPT2b expression. NPT2b has also been found to be highly expressed in human lung cancer tissues. The association of high expression of NPT2b in the lung with poor prognosis in oncogenic lung diseases prompted us to test whether knockdown of NPT2b may regulate lung cancer growth. To address this issue, aerosols that contained small interfering RNA (siRNA) directed against NPT2b (siNPT2b) were delivered into the lungs of K-ras (LA1) mice, which constitute a murine model reflecting human lung cancer. Our results clearly showed that repeated aerosol delivery of siNPT2b successfully suppressed lung cancer growth and decreased cancer cell proliferation and angiogenesis, while facilitating apoptosis. These results strongly suggest that NPT2b plays a role lung tumorigenesis and represents a novel target for lung cancer therapy.

Beclin1, as a key molecule in controlling autophagy pathway, can activate both cell survival and cell death pathway. As a role of autophagy in cancer progression remains controversial, introduction of beclin1 to the lungs of K-ras(LA1) mice was performed via inhalation. Prolonged autophagy activation was induced by repeated exposure of lentivirus-beclin1, total of 8 times (2 times/week, 4 weeks). By the time of sacrifice, lungs were collected and analyzed for the therapeutic efficacy. Total numbers of tumors on the surface and histopathological tumor progression were reduced in the lungs of K-ras(LA1) mice. Successful delivery of beclin1 induced autophagy and apoptosis in the target organ, which were confirmed by following features; increased autophagic vacuoles in the cytosol, increased number of mitochondria with decreased mitochondrial 12S RNA, and increased protein levels of mitochondria-related apoptosis. Markers for cell proliferation and angiogenesis, PCNA and VEGF, which used for prediction of cancer prognosis, were significantly reduced after introduction of beclin1. Taken together, the results indicate that autophagy regulating gene, beclin1, can be a potential target for lung cancer gene therapy.

Gene therapy using small interfering RNA (siRNA) is a novel strategy for effective anticancer therapies. However, low gene transfection efficiency and technical difficulties linked to siRNA delivery limit their practical application for gene delivery. Therefore, development of effective siRNA carriers is required. Overexpression of osteopontin (OPN) and its association with tumorigenesis has been reported in a majority of breast cancers. In this study, we used siRNA against OPN (siOPN) and investigated the possible OPN-dependent signaling pathway and the potential use of poly(amino ester) (PAE) based on glycerol propoxylate triacrylate (GPT) and spermine (SPE) for siRNA delivery. The GPT–SPE could effectively condense siRNA and protect the siRNA from RNaseA enzyme degradation. GPT–SPE/siRNA complexes showed good intracellular uptake and high gene silencing efficiency in vitro . Furthermore, in the breast cancer xenograft model, intratumoral injection of GPT–SPE/siOPN significantly inhibited tumor growth. These results demonstrated that silencing of OPN effectively suppressed the growth of breast cancer cells and further suggested that delivery of siRNA using GPT–SPE may act as an effective gene carrier for cancer therapy.

Conventional lung cancer therapies are associated with poor survival rates; therefore, new approaches such as gene therapy are required for treating cancer. Gene therapies for treating lung cancer patients can involve several approaches. Among these, aerosol gene delivery is a potentially more effective approach. In this study, Akt1 kinase-deficient (KD) and wild-type (WT) Akt1 were delivered to the lungs of CMV-LucR-cMyc-IRES-LucF dual reporter mice through a nose only inhalation system using glucosylated polyethylenimine and naphthalene was administrated to the mice via intraperitoneal injection. Aerosol delivery of Akt1 WT and naphthalene treatment increased protein levels of downstream substrates of Akt signaling pathway while aerosol delivery of Akt1 KD did not. Our results showed that naphthalene affected extracellular signal-regulated kinase (ERK) protein levels, ERK-related signaling, and induced Clara cell injury. However, Clara cell injury induced by naphthalene was considerably attenuated in mice exposed to Akt1 KD. Furthermore, a dual luciferase activity assay showed that aerosol delivery of Akt1 WT and naphthalene treatment enhanced cap-dependent protein translation, while reduced cap-dependent protein translation was observed after delivering Akt1 KD. These studies demonstrated that our aerosol delivery is compatible for in vivo gene delivery.

Background Metastasis to the lung may be the final step in the breast cancer-related morbidity. Conventional therapies such as chemotherapy and surgery are somewhat successful, however, metastasis-related breast cancer morbidity remains high. Thus, a novel approach to prevent breast tumor metastasis is needed. Methodology/Principal Finding Aerosol of lentivirus-based small hairpin osteopontin was delivered into mice with breast cancer twice a week for 1 or 2 months using a nose-only inhalation system. The effects of small hairpin osteopontin on breast cancer metastasis to the lung were evaluated using near infrared imaging as well as diverse molecular techniques. Aerosol-delivered small hairpin osteopontin significantly decreased the expression level of osteopontin and altered the expression of several important metastasis-related proteins in our murine breast cancer model. Conclusion/Significance Aerosol-delivered small hairpin osteopontin blocked breast cancer metastasis. Our results showed that noninvasive targeting of pulmonary osteopontin or other specific genes responsible for cancer metastasis could be used as an effective therapeutic regimen for the treatment of metastatic epithelial tumors.