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New method to prepare very stable and biocompatible fluorescent silica nanoparticles
Ha, Shin-Woo,Camalier, Corinne E.,Beck Jr., George R.,Lee, Jin-Kyu Royal Society of Chemistry 2009 Chemical communications Vol.2009 No.20
<P>A new synthetic method has been developed to prepare fluorescent silica nanoparticles without employing isothiocyanated dye molecules and (3-aminopropyl)triethoxysilane (APS) for the thiourea linkage formation; the resulting fluorescent silica nanoparticles show excellent photochemical, thermal and pH stabilities and a good biocompatibility with over 85% viability from various cell types.</P> <P>Graphic Abstract</P><P>Fluorescent silica nanoparticles prepared by a new method have excellent pH and thermal stability, and show cell viability greater than 85% at a level up to 100 μg ml<SUP>−1</SUP> over 72 h. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b902195g'> </P>
Ha, Shin-Woo,Camalier, Corinne E,Weitzmann, M Neale,Beck, George R,Lee, Jin-Kyu Marcel Dekker 2013 SOFT MATERIALS Vol.11 No.2
<P>Nanomaterials are diverse in size, shape and charge and these differences likely alter their physicochemical properties in biological systems. We have investigated how these properties alter the initial and long-term dynamics of endocytosis, cell viability, cell division, exocytosis, and interaction with a collagen extracellular matrix using silica-based fluorescent nanoparticles and the murine pre-osteoblast cell line, MC3T3-E1. Three surface modified nanoparticles were analyzed: positively charged (PTMA), negatively charged (OH), and neutrally charged polyethylene glycol (PEG). Positively charged PTMA-modified nanoparticles demonstrated the most rapid uptake, within 2 hours, while PEG modified and negatively charged OH nanoparticles demonstrated slower uptake. Cell viability was >80% irrespective of nanoparticle surface charge suggesting a general lack of toxicity. Long-term monitoring of fluorescent intensity revealed that nanoparticles were passed to daughter cells during mitotic cell division with a corresponding decrease in fluorescent intensity. These data suggest that irrespective of surface charge silica nanoparticles have the potential to internalize into osteoblasts, albeit with different kinetics. Furthermore, long lived nanoparticles have the potential to be transferred to daughter cells during mitosis and can be maintained for weeks intracellularly or within a collagen matrix without toxicity and limited exocytosis.</P>
Elevated Inorganic Phosphate Stimulates Akt-ERK1/2-Mnk1 Signaling in Human Lung Cells
Chang, Seung-Hee,Yu, Kyeong Nam,Lee, Yeon-Sook,An, Gil-Hwan,Beck Jr., George R.,Colburn, Nancy H.,Lee, Kee-Ho,Cho, Myung-Haing American Thoracic Society 2006 American journal of respiratory cell and molecular Vol.35 No.5
<P>Inorganic phosphate (Pi) plays a critical role in diverse cellular functions. Among three classes of sodium/phosphate co-transporters (NPTs), two types have been identified in mammalian lung. The potential importance of Pi as a novel signaling molecule and pulmonary expression of NPTs with poor prognosis of diverse lung diseases including cancer have prompted us to begin to define the pathways by which Pi regulates nontumorigenic human bronchial epithelial cells. Pi activates Akt phosphorylation on Thr308 specifically, and activated signal transmits on the Raf/MEK/ERK signaling. Here, we report that Pi controls cell growth by activating ERK cascades and by facilitating the translocation of Mnk1 from cytosol into nucleus through an Akt-mediated MEK pathway. Sequentially, translocated Mnk1 increases eIF4E-BP1 phosphorylation. As a result, Pi stimulates cap-dependent protein translation. Such Akt-mediated signaling of inorganic phosphate may provide critical clues for treatment as well as prevention of diverse lung diseases.</P>
Hwang, Soon-Kyung,Lim, Hwang-Tae,Minai-Tehrani, Arash,Lee, Eun-Sun,Park, Jongmin,Park, Seung Bum,Beck Jr., George R.,Cho, Myung-Haing American Thoracic Society 2009 American journal of respiratory and critical care Vol.179 No.12
<P>RATIONALE: Difficulties in achieving long-term survival of patients with lung cancer treated with conventional therapies suggest that novel approaches are required. Recent advances in aerosol-mediated gene delivery have provided the possibility of an alternative for the safe and effective treatment of lung cancer. OBJECTIVES: To investigate the repeated effect of carboxyl-terminal modulator protein (CTMP) on multistage lung tumorigenesis. In this study, we addressed this question by studying the effects of lentivirus-based CTMP in the lungs of 9- and 13-week-old K-ras(LA1) mice, a model of lung cancer. METHODS: An aerosol of lentivirus-based CTMP was delivered into 9- and 13-week-old K-ras(LA1) mice, a model of lung cancer, through a nose-only inhalation system twice a week for 4 weeks. The effects of CTMP on lung cancer progression and Akt-related signals were evaluated. MEASUREMENTS AND MAIN RESULTS: Long-term repeated delivery of CTMP effectively reduced tumor progression in the lungs at different stages of development. Lentiviral-CTMP inhibited protein synthesis and cell cycle and altered Akt signaling pathway in the lungs of 9-week-old K-ras(LA1) mice, and increased apoptosis was observed in the lungs of 13-week-old K-ras(LA1) mice. CONCLUSIONS: Long-term repeated viral delivery of CTMP may provide a useful tool for designing lung tumor treatment.</P>
Xu, Cheng-Xiong,Jere, Dhananjay,Jin, Hua,Chang, Seung-Hee,Chung, Youn-Sun,Shin, Ji-Young,Kim, Ji-Eun,Park, Sung-Jin,Lee, Yong-Hoon,Chae, Chan-Hee,Lee, Kee Ho,Beck, George R,Cho, Chong-Su,Cho, Myung-Ha American Lung Association 2008 American journal of respiratory and critical care Vol.178 No.1
<P>RATIONALE: The low efficiency of conventional therapies in achieving long-term survival of patients with lung cancer calls for the development of novel therapeutic options. Recent advances in aerosol-mediated gene delivery have provided the possibility of an alternative for the safe and effective treatment of lung cancer. OBJECTIVES: To demonstrate the feasibility and emphasize the importance of noninvasive aerosol delivery of Akt1 small interfering RNA (siRNA) as an effective and selective option for lung cancer treatment. METHODS: Nanosized poly(ester amine) polymer was synthesized and used as a gene carrier. An aerosol of poly(ester amine)/Akt1 siRNA complex was delivered into K-ras(LA1) and urethane-induced lung cancer models through a nose-only inhalation system. The effects of Akt1 siRNA on lung cancer progression and Akt-related signals were evaluated. MEASUREMENTS AND MAIN RESULTS: The aerosol-delivered Akt1 siRNA suppressed lung tumor progression significantly through inhibiting Akt-related signals and cell cycle. CONCLUSIONS: The use of poly(ester amine) serves as an effective carrier, and aerosol delivery of Akt1 siRNA may be a promising approach for lung cancer treatment and prevention.</P>
Jin, Hua,Hwang, Soon-Kyung,Yu, Kyungnam,Anderson, Hanjo K.,Lee, Yeon-Sook,Lee, Kee Ho,Prats, Anne-Catherine,Morello, Dominique,Beck Jr., George R.,Cho, Myung-Haing Oxford University Press 2006 TOXICOLOGICAL SCIENCES Vol.90 No.1
<P>Inorganic phosphate (Pi) plays a key role in diverse physiological functions. Recently, considerable progress has been made in our understanding of the function and regulation of the brain-specific sodium-dependent inorganic phosphate transporter 1 (NPT1), which is found to exist principally in cerebrum and cerebellum. The potential importance of Pi as a novel signaling molecule and the poor prognosis of diverse neurodegenerative diseases that involve brain-specific NPT1 have prompted us to define the pathways by which Pi affects mouse brain growth. A high phosphate diet caused an increase in serum Pi accompanied by a decrease in calcium, and a decrease in body weight coupled with a decreased relative weight of cerebellum. A high phosphate diet caused a significant increase in protein expression of NPT1, both in cerebrum and cerebellum. Additionally, the high phosphate diet increased Homo sapiens v-akt murine thymoma viral oncogene homolog 1 (Akt) phosphorylation at Ser473 in cerebrum and cerebellum, whereas suppression of Akt phosphorylation at Thr308 was observed only in cerebellum. Selective suppression of eukaryotic translation initiation factor-binding protein (eIF4E-BP1) in cerebrum was induced by high levels of Pi, which induced cap-dependent and cap-independent protein translation in cerebrum and cerebellum, respectively. Phosphorylation of extracellular regulated kinase 1 (ERK1) in comparison with that of ERK2 was significantly reduced in both cerebrum and cerebellum. High levels of Pi reduced protein expressions of proliferating cell nuclear antigen (PCNA) and cyclin D1 in cerebrum and cerebellum. In conclusion, the results indicate that high dietary Pi can perturb normal brain growth, possibly through Akt-ERK signaling in developing mice.</P>
Suppression of A549 lung cancer cell migration by precursor let-7g microRNA.
Park, Sungjin,Minai-Tehrani, Arash,Xu, Cheng-Xiong,Chang, Seung-Hee,Woo, Min-Ah,Noh, Mi-Suk,Lee, Eun-Sun,Lim, Hwang-Tae,An, Gil-Hwan,Lee, Kee-Ho,Sung, Ha-Jung,Beck, George R,Cho, Myung-Haing D. A. Spandidos 2010 MOLECULAR MEDICINE REPORTS Vol.3 No.6
<P>Let-7g miRNAs, short non-coding RNAs approximately 21 nucleotides long, repress protein translation by binding to the 3'UTR of target mRNAs. Aberrant expression of let-7g is associated with the poor prognosis of lung cancer patients. Compared to normal lung cells, let-7g expression is absent in non-small cell lung cancer (NSCLC) cells. Furthermore, K-Ras and HMGA2 are well known as targets of let-7g. In this study, we evaluated the potential role of precursor (pre)-let-7g in lung cancer cell metastasis, focusing on the two targets of let-7g, HMGA2 and K-Ras. We found that pre-let-7g inhibited the migration of A549 lung cancer cells through HMGA2-mediated E2F1 down-regulation. Thus, our results suggest that pre-let-7g could be used as a suitable target for the suppression of lung cancer cell migration.</P>
Min Young Kim,Kyung Suk Song,Gun Ho Park,Hyun Woo Kim,Jin Hong Park,Jun Sung Kim,Hwa Jin,Kook Jong Eu,Hyun Sun Cho,Gami Kang,Chanhee Chae,Yoon Shin Kim,Young Chul Kim,Hae Yeong Kim,George Beck,Nancy C 한국독성학회 2004 Toxicological Research Vol.20 No.1
Changes in cell cycle control in the lungs and liver of the B6C3F1 mice (20 males per each group) exposed to ozone (0.5 ppm), 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK, 1.0 mg/kg), and dibutyl phthalate (DBP, 5,000 ppm) after 52 weeks were examined through Western, Northern blot, and immunohistochemistry based on alterations in protein expression levels of G1/S checkpoints (cyclin D1, cyclin E, and PCNA), G2/M checkpoints (cyclin B1, cyclin G, and cyclin A), negative regulators (p53, p21, GADD45, and p27), and positive regulator (mdm2). Expression levels of cyclins D1, E, G, PCNA, mutant p53, and mdm2 proteins were higher in the lungs<br/> and livers treated with combination of toxicants than in those treated with ozone only. Expression levels of the wild-type and mutant p53, p21, GADD45, p27, and mdm2 proteins and mRNAs were<br/> higher in toxicant-treated groups than those of the control. Immunohistochemical analysis revealed staining intensities of the PCNA, cyclin D1, c-myc and mdm2 protein- treated lungs and livers were stronger than those of the control group. Our results showed that combined treatment of ozone with NNK/DBP altered the cell cycle control through instability of the wild-type p53 gene. Such pivotal p53-mediated cell cycle alterations may be responsible for the toxicity observed under our experimental condition. These results may be applied to risk assessment of mixture-induced toxicity.