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ABSTRACT: Pancreatic cancer is one of the most malignant tumor diseases with the characters of aggressive growth and metastasis. With the inefficiency of the current therapeutics, new potential targets and new therapeutic agents for healing of pancreatic cancer are critically needed. We have previously found a small molecule, named 4-tert-butyl-2-((cyclohexylamino) methyl)-6-methylphenol (TBMMP, NSC number: 48160), which can freeze the intermediate of Ras-GTP hydrolysis in the open non-signaling conformation with high affinity and high specificity in silico. In this work, we studied the effect and mechanism of TBMMP on two pancreatic cancer cell lines, CFPAC-1 and BxPC-3. The results showed that TBMMP could restrain the growth of the pancreatic cancer cells with IC(50) value 84.3 μM for CPFAC-1 and 94.5 μM for BxPC-3, respectively. Additionally, TBMMP increased cytochrome c release, reduced mitochondrial membrane potential, activated caspase-3, -9, elevated ROS and increased expression of the Bax in the pancreatic cancer cell lines. Collectively, the results indicated that TBMMP induced the apoptosis of pancreatic cancer cells through the mitochondrial pathway. Further, we also found that TBMMP could suppress the metastasis of both pancreatic cancer cells in vitro. Taken together, we proposed that TBMMP might be a therapeutic potential lead for treating patients with pancreatic cancer.
European journal of pharmaceutical sciences: official journal of the European Federation for Pharmaceutical Sciences 01/2013; · 2.61 Impact Factor
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ABSTRACT: Herein, folic acid (FA) conjugated with AuNPs were introduced into the cancer cell imaging via the specific interaction between FA and the folate receptor on the cell surface. FA protected gold nanoparticles (AuNPs) was synthesized and labeled with fluorescein isothiocynate (FITC) to form the FITC-FA-AuNPs (FFANPs). As over-expressed folic acid receptor in some cancer cells and folic acid can specifically and selectively combine, the FFANPs can bind to the FR expressed on tumor cells such as HeLa cells (human epithelial cervical cancer) and CERF-CEM cells (T cell line, human acute lymphoblastic leukemia). As a result, cancer cell imaging can be achieved. To ascertain the FR target ability, it has been acquired by FR-targeted images using synthetic FFANPs. The formation of FITC-FA can be identified by MS. FCM was carried out to study the cell uptake of FFANPs. The cell toxicity (3-[4,5-dimethylthiazolyl-2]-2, 5-diphenyltetrazolium bromide, MTT) assay demonstrated that the FITC-labeled conjugate had only little effect on the cytotoxicity to the cells, which further proved the applicability of the method in tumor cell imaging.
Talanta 11/2012; 101:32-7. · 3.79 Impact Factor
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ABSTRACT: Computer-aided drug design (CADD) plays a significant role in all stages of today's drug discovery. Many CADD technologies and methods were employed in finding various inhibitors against different targets in the past years. In this review, the most commonly molecular modeling methods of computer-aided drug design are discussed. However, how to integrate these computational methods and/or combine them with experiments to improve the hit rate of novel scaffolds is still a challenge. In addition, the present study reviews the ISR (intrinsic specificity ratio) as a new concept and quantitative criterion for specificity to be applied as a complement in addition to binding affinity for finding new drug leads. Molecular modeling and experimental studies using Ras protein as a test example are performed and the drug specificity is studied in order to discover the novel chemical compounds with minimal side effects. These studies also investigate the in vitro inhibition assay of the soluble compounds evaluating tumor-specific cytotoxicity on different cell lines. The results suggest that ISR is useful in quantitative assessment of specificity of small molecules.
Current pharmaceutical design 10/2012; · 4.41 Impact Factor
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ABSTRACT: Pancreatic cancer is one of lethal and poor prognostic malignancies. Due to the absence of effective detecting methods, quite a number of efforts have been made to improve a survival advantage for treatment in patients with pancreatic cancer. Over the past decade, single-agent gemcitabine and gemcitabine-containing combinations were considered standard first-line therapies for advanced pancreatic cancer. Although these routine uses of chemotherapy failed to significantly improve survival benefit for most therapies, these trials provided insights into the molecular mechanisms involved in the development of pancreatic cancer and therefore opened up new therapeutic avenues. Apoptotic inducer as a therapeutic concept has been widely proposed and experimentally identified in some works. Some reviews have revealed that apoptosis-inducing was a promising therapy in cancers with the least side effects and more effectiveness. Apoptosis is a highly controlled physiological mechanism and proceeds through two major pathways for apoptosis-inducing. Some anticancer drugs kill cancer cells by inducing apoptosis via death receptor pathway; however, other chemotherapeutic drugs trigger apoptosis via mitochondrial pathway. In this review, we summarize briefly current chemotherapy in pancreatic cancer, describe the apoptotic mechanisms, and provide a novel therapeutic strategy by targeting Ras intermediate.
Current pharmaceutical design 10/2012; · 4.41 Impact Factor
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ABSTRACT: In this article, we reported a novel approach for in situ labeling and imaging HeLa cancer cells utilizing a bifunctional aptamer (AS1411) and its fluorescent ligand, protoporphyrin IX (PPIX). In the presence of potassium ion, AS1411 folded to G-quadruplex structure, binded fluorescent ligand (PPIX) with fluorescent enhancement, and targeted the nucleolin overexpressed by cancer cells. Consequently, bioimaging of cancer cells specifically were realized by laser scanning confocal microscope. The bioimaging strategy with AS1411-PPIX complex was capable to distinguish HeLa cancer cells from normal cells unambiguously, and fluorescence imaging of cancer cells was also realized in human serum. Moreover, the bioimaging method was very facile, effective and need not any covalent modification. These results illustrated that the useful approach can provide a novel clue for bioimaging based on non-covalent bifunctional aptamer in clinic diagnosis.
Analytica chimica acta 09/2012; 741:93-9. · 4.31 Impact Factor
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ABSTRACT: Gallic acid (GA) is a plant phenol isolated from water caltrop which is reported to have anti-inflammatory and anti-cancer effects. In this study, the antiproliferative effect of GA on human pancreatic cancer cell lines CFPAC-1 and MiaPaCa-2 as well as hepatocytes HL-7702 as normal cells was examined. Particularly, the mechanism of GA-induced apoptosis in MiaPaCa-2 cells in vitro was further studied.
Cell viability was measured using SRB assay, and apoptosis was detected by Hoechst staining and annexin V-PI staining assays. Mitochondrial membrane potential was detected by rhodamine-123 staining. Flow cytometry analysis was employed to detect the apoptosis-related events.
GA inhibited the proliferation of CFPAC-1 and MiaPaCa-2 cells in a time- and dose-dependent manner, with IC(50)S of 102.3 ± 2.4 and 135.2 ± 0.6 µM at 48 h, respectively. GA treatment led to the increased proportion of cell apoptosis from 12.5 ± 0.72 to 78.3 ± 2.48% at the concentrations of 6.25 and 25.0 µg/ml, which was evidenced again by chromatins staining assay. Also, GA activated caspase-3, caspase-9, and reactive oxygen species, elevated Bax expression and [Ca(2+)](i) and reduced mitochondrial membrane potential (ΔΨm) in MiaPaCa-2 cells. Remarkably, when compared with human normal cells HL-7702 (IC(50) >100 µg/ml), GA showed selective toxicity for cancer cells.
GA can function as a cancer-selective agent by inducing apoptosis in MiaPaCa-2 cells via the mitochondria-mediated pathways. To the best of our knowledge, GA should open up new opportunities for the therapy of pancreatic cancer.
Chemotherapy 06/2012; 58(3):185-94. · 1.82 Impact Factor
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ABSTRACT: Pancreatic cancer is considered a lethal and treatment-refractory disease. To obtain a potent anticancer drug, the cytotoxic effect of 2-(benzo[d]oxazol-3(2H)-ylmethyl)-5-((cyclohexylamino)methyl)benzene-1,4-diol, dihydrochloride (NSC48693) on human pancreatic cancer cells CFPAC-1, MiaPaCa-2, and BxPC-3 was assessed in vitro. The proliferation of CFPAC-1, MiaPaCa-2, and BxPC-3 is inhibited with IC(50) value of 12.9±0.2, 20.6±0.3, and 6.2±0.6 µM at 48 h, respectively. This discovery is followed with additional analysis to demonstrate that NSC48693 inhibition is due to induction of apoptosis, including Annexin V staining, chromatins staining, and colony forming assays. It is further revealed that NSC48693 induces the release of cytochrome c, reduces mitochondrial membrane potential, generates reactive oxygen species, and activates caspase. These results collectively indicate that NSC48693 mainly induces apoptosis of CFPAC-1, MiaPaCa-2, and BxPC-3 cells by the mitochondrial-mediated apoptotic pathway. Excitingly, the study highlights an encouraging inhibition effect that human embryonic kidney (HEK-293) and liver (HL-7702) cells are more resistant to the antigrowth effect of NSC48693 compared to the three cancer cell lines. From this perspective, NSC48693 should help to open up a new opportunity for the treatment of patients with pancreatic cancer.
PLoS ONE 01/2012; 7(6):e37841. · 4.09 Impact Factor
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ABSTRACT: A significant increase (ca. 22-fold) in the electricity generation due to a Shewanella oneidensis MR-1 biofilm was observed in the presence of Fe(3)O(4)/Au nanocomposites.
Chemical Communications 10/2010; 46(38):7172-4. · 6.17 Impact Factor
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ABSTRACT: The molecular analysis of thymopentin (TP5)/class II major histocompatibility complex (MHC II) complexes has been basically understood; however, the mechanism by which TP5-MHC II complexes are formed is largely unexplored. Compared with Epstein-Barr virus (EBV)-transformed B cells expressing human leucocyte antigen DR (HLA-DR), no fluorescent signal was observed on the DR-deficient cell line. This indicates that FITC labeled TP5 (FITC-TP5) is genuinely bound to HLA-DR. The binding specificity was confirmed by incubating FITC-TP5 with unlabeled TP5 and HA peptide as well as mAb for DR molecules. In addition, the binding appeared to be rapid in living antigen-presenting cell (APC), which implies that TP5 is demonstrated on APC surface and does not require processing before associating with DR. Additional support for this surface binding arises from the observation that pretreatment of cells with a variety of metabolic inhibitors failed to decrease the level of TP5/DR complexes. However, temperature has an effect on the rate of binding between TP5 and DR molecules, which is well consistent with the qualitative predication of transition state theory. The formation of antigenic complexes is accelerated at acidic pH, which shows that the formation of TP5/DR complexes is a pH-dependent process.
The Journal of Physical Chemistry B 12/2009; 114(1):638-42. · 3.70 Impact Factor
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ABSTRACT: The development of transfection enhancement of liposomes with attributes of high stability and easy handling in gene therapy is challenging. In this study, we report didodecyldimethylammonium bromide (DDAB, a cationic lipid) coated gold nanoparticles (DDAB-AuNPs), which can enhance the transfection efficiency generated by two kinds of commercially available cationic liposomes: Lipotap and DOTAP. It showed that DDAB-AuNPs at the optimal concentrations could produce more than 2 times increase when measuring the number of cells expressed green fluorescent protein and 48-fold increase for luciferase levels after transfection, respectively. The electrophoretic mobility shift assay (EMSA) and confocal laser scanning microscopy (CLSM) experiments showed that more DNA molecules binding to the lipoplexes after adding DDAB-AuNPs. In addition, the flow cytometry (FCM) results indicated that DDAB-AuNPs increased cellular uptake efficiency of DNA molecules, which might account for the enhancement of transfection efficiency. It has also been found that the DDAB-AuNPs could decrease the cytotoxicity of liposomes to the cells.
Biomaterials 11/2009; 31(7):1850-7. · 7.40 Impact Factor
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ABSTRACT: The affinity and specificity of drugs with human serum albumin (HSA) are crucial factors influencing the bioactivity of drugs. To gain insight into the carrier function of HSA, the binding of levamlodipine with HSA has been investigated as a model system by a combined experimental and theoretical/computational approach. The fluorescence properties of HSA and the binding parameters of levamlodipine indicate that the binding is characterized by one binding site with static quenching mechanism, which is related to the energy transfer. As indicated by the thermodynamic analysis, hydrophobic interaction is the predominant force in levamlodipine-HSA complex, which is in agreement with the computational results. And the hydrogen bonds can be confirmed by computational approach between levamlodipine and HSA. Compared to predicted binding energies and binding energy spectra at seven sites on HSA, levamlodipine binding HSA at site I has a high affinity regime and the highest specificity characterized by the largest intrinsic specificity ratio (ISR). The binding characteristics at site I guarantee that drugs can be carried and released from HSA to carry out their specific bioactivity. Our concept and quantification of specificity is general and can be applied to other drug-target binding as well as molecular recognition of peptide-protein, protein-protein, and protein-DNA interactions.
Biophysical Journal 06/2009; 96(10):3917-25. · 3.65 Impact Factor
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ABSTRACT: A simple, rapid and ultrasensitive colorimetric detection of protein using aptamer-Au nanoparticles (AuNPs) conjugates based on a dot-blot array has been developed, which was combined with the unique optical properties of AuNPs, enabling the visual detection of protein within minutes without any instrument.
Chemical Communications 07/2008; · 6.17 Impact Factor
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ABSTRACT: Thymopentin (TP5) triggers an immune response by contacting with T cells; however the molecular basis of how TP5 achieves this process remains incompletely understood. According to the main idea of immunomodulation, we suppose that it would be necessary for TP5 to form complex with human class II major histocompatibility complex DR molecules (HLA-DR) before TP5 interacts with T cells. The uptake of TP5 by EBV-transformed B cells expressing HLA-DR molecules and the histogram of fluorescence intensities were observed by using fluorescent- labeled TP5, testifying the direct binding of TP5 to HLA-DR. The binding specificity was confirmed by the inhibition with unlabeled TP5, suggesting the recognition of TP5 by HLA-DR. To confirm the interaction between TP5 and HLA-DR, the complex formation was predicted by using various modeling strategies including six groups of trials with different parameters, alanine substitutions of TP5, and the mutants of HLA-DR. The results demonstrated that TP5 and its alanine substitutions assumed distinct conformations when they bound to HLA-DR. The observation further showed that there was flexibility in how the peptide bound within the binding cleft. Also, the molecular analysis supplemented a newly important discovery to the effect of Val anchor on TP5 binding HLA-DR, and revealed the important effects of Glu11 and Asn62 on the recognition of TP5. These results demonstrated the capability of TP5 to associate with HLA-DR in living antigen presenting cells (APC), thereby providing a new and promising strategy to understand the immunomodulation mechanism induced by TP5 and to design potential immunoregulatory polypeptides.
PLoS ONE 02/2007; 2(12):e1348. · 4.09 Impact Factor
