[Show abstract][Hide abstract] ABSTRACT: Pharmacokinetic research in China on the use of voriconazole in critically ill adult patients with different pulmonary diseases remains to be explored. This study evaluated the population pharmacokinetics of the use of voriconazole (VRC) in critically ill patients to determine covariate effects on VRC pharmacokinetics by NONMEM, which could further optimize VRC dosing in this population. A one-compartment model with first-order absorption and elimination best fit the data, giving 4.28 L/h clearance and 93.4 L volume of distribution of VRC. The model variability, described as an approximate percentage coefficient of interindividual variability in clearance and volume of distribution, was 72.94% and 26.50%, respectively. A significant association between Cmin and drug response or grade 2 hepatotoxicity was observed (p=0.002, <0.001, respectively, 1.5-4.0 µg/mL) via logistic multivariate regression. Monte Carlo simulations at 100, 150, 200, and 250 mg dosage predicted effectiveness at 45.99%, 99.76%, 98.76%, and 67.75% within the 1.5-4.0 µg/mL range, suggesting that a 150 or 200 mg intravenous dose twice daily is best suited to achieve the target steady state trough concentration range in critically ill patients with pulmonary disease.
[Show abstract][Hide abstract] ABSTRACT: Structure activity relationship (SAR) of fibroblast activation protein alpha (FAP) inhibitors will be useful to evaluate bioactivities of candidates. To discuss SAR of FAP inhibitors, two alignment styles were carried out to build QSAR models of FAP inhibitors. HQSAR was used to construct 2D-QSAR after the selection of training set and test set by principal component analysis method. Meanwhile, 3D-QSAR models were constructed by comparative molecular field analysis and comparative molecular similarity indices analysis method and optimized by FOCUS method. All the QSAR models were validated by cross-validation and test set, and the targeted QSAR model was selected by comprehensive evaluation containing cross-validation coefficient, correlation coefficient and consistency with docking studies. The result suggests that 2D-QSAR model may be insufficient to evaluate SAR of FAP inhibitors, while 3D-QSAR model with S+H+D_F functional fields could be applied to characterize the SAR based on docking conformation alignment.
No preview · Article · Apr 2015 · Medicinal Chemistry Research
[Show abstract][Hide abstract] ABSTRACT: Z-GP-Dox, the FAPα (fibroblast activation protein-α)-based doxorubicin prodrug, demonstrates excellent tumor targeting effects and a favorable toxicokinetic profile. However, the insoluble nature of Z-GP-Dox becomes a significant barrier to drug administration, particularly when it comes to the clinical stage. Here we developed a nanomicelle system to facilitate the systemic delivery of Z-GP-Dox, and evaluated its disposition in rats following administration of the micelles using a physiologically-based pharmacokinetic model. Z-GP-Dox-loaded mixed nanomicelles (ZGD-MNs) were prepared by dispersion of an ethanol solution of Z-GP-Dox, lecithin, and sodium oleate in water. The obtained ZGD-MNs were 86.6 nm in size with a drug loading of 14.03%. ZGD-MNs were fairly stable in phosphate-buffered saline and showed satisfactory physical and chemical stability over a 2-week observation period. Accumulative drug release was more than 56% within 24 hours. Further, the physiologically-based pharmacokinetic rat model consisting of various organs (ie, heart, liver, spleen, lung, kidney, and intestine) was fitted to the experimental data following administration of ZGD-loaded cosolvent (control) or micelles. Derived partition coefficient values revealed that the nanomicelles significantly altered the biodistribution of Z-GP-Dox. Of note, drug distribution to the lung, liver, and spleen was greatly enhanced and the fold change ranged from 2.4 to 33. In conclusion, this is the first report of a mixed micelle system being a viable carrier for delivery of Z-GP-Dox. Also, the pharmacokinetic behavior of Z-GP-Dox was satisfactorily described by the physiologically-based pharmacokinetic model.
Full-text · Article · Feb 2015 · International Journal of Nanomedicine
[Show abstract][Hide abstract] ABSTRACT: Purpose
P-glycoprotein mediated efflux is one of the main mechanisms for multidrug resistance in cancers, and 3-Bromopyruvate acts as a promising multidrug resistance reversal compound in our study. To test the ability of 3-Bromopyruvate to overcome P-glycoprotein-mediated multidrug resistance and to explore its mechanisms of multidrug resistance reversal in MCF-7/ADR cells, we evaluate the in vitro and in vivo modulatory activity of this compound.
The in vitro and in vivo activity was determined using the MTT assay and human breast cancer xenograft models. The gene and protein expression of P-glycoprotein were determined using real-time polymerase chain reaction and the Western blotting technique, respectively. ABCB-1 bioactivity was tested by fluorescence microscopy, multi-mode microplate reader, and flow cytometry. The intracellular levels of ATP, HK-II, and ATPase activity were based on an assay kit according to the manufacturer’s instructions.
3-Bromopyruvate treatment led to marked decreases in the IC50 values of selected chemotherapeutic drugs [e.g., doxorubicin (283 folds), paclitaxel (85 folds), daunorubicin (201 folds), and epirubicin (171 folds)] in MCF-7/ADR cells. 3-Bromopyruvate was found also to potentiate significantly the antitumor activity of epirubicin against MCF-7/ADR xenografts. The intracellular level of ATP decreased 44%, 46% in the presence of 12.5.25 µM 3-Bromopyruvate, whereas the accumulation of rhodamine 123 and epirubicin (two typical P-glycoprotein substrates) in cells was significantly increased. Furthermore, we found that the mRNA and the total protein level of P-glycoprotein were slightly altered by 3-Bromopyruvate. Moreover, the ATPase activity was significantly inhibited when 3-Bromopyruvate was applied.
We demonstrated that 3-Bromopyruvate can reverse P-glycoprotein-mediated efflux in MCF-7/ADR cells. Multidrug resistance reversal by 3-Bromopyruvate occurred through at least three approaches, namely, a decrease in the intracellular level of ATP and HK-II bioactivity, the inhibition of ATPase activity, and the slight decrease in P-glycoprotein expression in MCF-7/ADR cells.
[Show abstract][Hide abstract] ABSTRACT: Macrophages are heterogeneous and plastic populations that are an essential component of inflammation and host defense. To understand how macrophages respond to cytokine signals, we used 2-DE to identify protein profiles in macrophages stimulated with interleukin 4 (M2) and those stimulated with lipopolysaccharide and interferon γ (M1). In total, 32 differentially expressed proteins in THP-1 cells were identified by MALDI-TOF MS/MS analysis. The different proteins were mainly involved in cellular structure, protein metabolism, stress response, oxidative response, and nitric oxide production during macrophage polarization. In particular, proteins playing important roles in production of nitric oxide (NO) were down-regulated in M2 macrophages. Many antioxidant and heat shock proteins, which are related to oxidative response, were up-regulated in M2 macrophages. More importantly, a remarkable decrease in intracellular reactive oxygen species (ROS) and NO production were detected in M2 macrophages. Our results provide a proteomic profile of differentially polarized macrophages and validate the function of the identified proteins, which may indicate possible mechanism of macrophage polarization process.This article is protected by copyright. All rights reserved
[Show abstract][Hide abstract] ABSTRACT: Nodal, an important embryonic morphogen, has been reported to function in tumorigenesis. Here we report for the first time that Nodal promotes malignancy by inducing epithelial-mesenchymal transition (EMT) in B16 murine melanoma. These cells displayed increased migration and invasion abilities upon treating with Nodal, accompanying with typical phenotype changes of EMT. In contrast, Nodal knockdown or blocking Nodal signaling using a specific antagonist SB431542 repressed the EMT phenotype as well as reduced cell motility and invasiveness. Treatment with Nodal also induced expression of transcription factor Snail. Snail knockdown abolished the Nodal-induced EMT in B16 cells. We further show that Snail expression is mediated by the Nodal-regulated AKT/GSK-3β signaling. Taken together, these results revealed that Nodal promotes the aggressive phenotype of B16 murine melanoma cells by inducing EMT via up-regulation of Snail. This study provides a better understanding of Nodal function in melanoma, and suggests a potential novel target for clinical therapeutic research.
[Show abstract][Hide abstract] ABSTRACT: Andrographolide derivatives have been reported as potential α-glucosidase inhibitors. A more detailed investigation of active sites and key residues of α-glucosidase, which can interact with andrographolide derivatives, is useful for the discovery of more effective α-glucosidase inhibitors. To establish a virtual method predicting potential active sites and key residues, a 3D structure of α-glucosidase from baker's yeast was first constructed by homology modeling (RMSD of alignment was 1.745Å). The SiteID program was then used to explore the potential binding sites of the homology model of α-glucosidase. Based on these potential binding sites, 25 andrographolide derivatives were docked into the hoamology model of α-glucosidase for determining the potential active sites. Results showed that the predicted strong inhibitors' AR (accuracy rate) of the two potential active sites, P7 and P10, were 77.8% and 88.9% respectively. To further research the potential active sites, key residues of these predicted active sites were investigated through the virtual residues knockout method. VAL316 and THR307, residues of P7, and HIS258, LYS262, ILE271, MET272, THR273, ALA289, TYR292, and SER295, as well as residues of P10, were found to contribute greatly to the high ARs of their corresponding active sites. These results may be useful for design of new α-glucosidase inhibitors.
No preview · Article · Jun 2011 · Letters in Drug Design & Discovery
[Show abstract][Hide abstract] ABSTRACT: Fibroblast activation protein-α (FAPα) is a tumor-associated antigen uniquely expressed by reactive stromal fibroblasts in the majority of human epithelial tumors. FAPα also possesses both post-prolyl peptidase and endopeptidase activities. Consequently, FAPα is increasingly considered as a potential pan-tumor target for designing tumor-targeted prodrugs. We previously conjugated Doxorubicin (Dox) with a FAPα-specific dipeptide (Z-Gly-Pro) to develop a FAPα-targeting prodrug of Dox (FTPD). The aim of current work was to validate the tumor targeting of this targeted-delivery strategy. The results demonstrated that FTPD could effectually release Dox upon the hydrolysis of FAPα as well as the incubation with tumor homogenate of FAPα-positive tumor (4T1 tumor), while it was highly stable in mouse plasma and a variety of tissue homogenates including heart, liver, and so on. And the FAPα-cleaved FTPD exhibited significantly higher cytotoxicity against 4T1 cells in vitro than the uncatalyzed prodrug. Additionally, FTPD produced similar antitumor efficacy in 4T1 tumor-bearing mice to free Dox without obvious cardiotoxic effect. Moreover, subsequent study indicated that the accumulation of FTPD reduced significantly in the heart compared to free Dox. These findings suggest that such FAPα-based prodrug strategy is promising to achieve targeted delivery of antitumor agents.
Preview · Article · Feb 2011 · Journal of Drug Targeting
[Show abstract][Hide abstract] ABSTRACT: Andrographolide derivatives were shown to inhibit alpha-glucosidase. To investigate the relationship between activities and structures of andrographolide derivatives, a training set was chosen from 25 andrographolide derivatives by the principal component analysis (PCA) method, and a quantitative structure-activity relationship (QSAR) was established by 2D and 3D QSAR methods. The cross-validation r(2) (0.731) and standard error (0.225) illustrated that the 2D-QSAR model was able to identify the important molecular fragments and the cross-validation r(2) (0.794) and standard error (0.127) demonstrated that the 3D-QSAR model was capable of exploring the spatial distribution of important fragments. The obtained results suggested that proposed combination of 2D and 3D QSAR models could be useful in predicting the alpha-glucosidase inhibiting activity of andrographolide derivatives.
Preview · Article · Mar 2010 · International Journal of Molecular Sciences
[Show abstract][Hide abstract] ABSTRACT: Human bone marrow mesenchymal stromal cells (hBMSC) have been shown to participate in malignant transformation. However, hampered by the low frequency of malignant transformation of hBMSC, we do not yet know how to prevent malignant transformation of implanted hBMSC. In this study, in order to establish a model for the eradication of hBMSC-derived malignant cells, a gene fusion consisting of a human telomerase (hTERT) promoter modified with both c-Myc and myeloid zinc finger protein2 (MZF-2) binding elements and followed by the E. coli cytosine deaminase (CD) and luciferase genes was stably transferred into hBMSC via lentiviral transduction; n-phosphonacelyl-L-aspartic acid (PALA) selection was used to generate malignant cell colonies derived from transduced hBMSC after treatment with the carcinogenic reagent BPDE. Cells that were amplified after PALA selection were used for transplantation and 5-FC pro-drug cytotoxicity tests. The results showed that PALA-resistant malignant cells could be generated from hBMSC co-induced with lentiviral transduction and treatment with Benzo(a)pyrene Diol Epoxide (BPDE); the modification of c-Myc and MZF-2 binding elements could remarkably enhance the transcriptional activities of the hTERT promoter in malignant cells, whereas transcriptional activity was depressed in normal hBMSC; malignant cells stably expressing CD under the control of the modified hTERT promoter could be eliminated by 5-FC administration. This study has provided a method for targeted eradication of malignant cells derived from hBMSC.
No preview · Article · Feb 2010 · Experimental Cell Research
[Show abstract][Hide abstract] ABSTRACT: The present study investigated an immunotherapeutic strategy for rearranged during transfection proto-oncogene (ret)-associated carcinomas in a transgenic MT/ret 304/B6 mouse model in which spontaneous tumors develop due to overexpression of the ret gene. A Ret peptide vaccine comprising an extracellular fragment of Ret protein and Th1-polarized immunoregulator CpG oligonucleotide (1826) induced strong and specific cellular and humoral immune responses in wild-type C57BL/6 mice, showing that the Ret peptide has a strong immunogenic potential as part of an antitumor vaccine. In MT/ret 304/B6 mice, however, the vaccine was only modestly effective as an inducer of the humoral immune response, and it failed to elicit a T-cell response. An immunohistochemical analysis revealed marked indoleamine 2,3-dioxygenase expression after immunization with Ret peptide vaccine in the lymph nodes and spleens of MT/ret 304/B6 mice. The systemic administration of the potent inhibitor of indoleamine 2,3-dioxygenase 1-methyl tryptophan (1MT) along with Ret vaccine produced a significant increase in tumor-specific cytotoxic activity. A delay in spontaneous tumor development was also observed in the MT/ret 304/B6 mice to which the Ret vaccine and 1MT were administered. These results indicate that an improved Ret vaccine composed of Ret peptide plus CpG oligonucleotide plus 1MT is a potential therapeutic strategy for treatment of ret-associated carcinomas.
[Show abstract][Hide abstract] ABSTRACT: The combination of sodium butyrate (NaB) and ganciclovir (GCV) was considered to be a noteworthy therapeutic strategy in Epstein-Barr virus (EBV)-associated cancers. However, clinical studies have indicated that an extremely high dose of NaB is required to obtain the expected curative efficacy. This obviously limits the practical clinical application of the two drugs combined. In this study, we investigated the possibility of sensitizing tumor cells to NaB and GCV mediated cytotoxicity by modulating intracellular signal pathways. The results showed that the disruption of Ras/Raf activity by expressing dominant negative forms of both Ras and Raf-1 did not alter the potency of the NaB and GCV combination in the EBV-positive cell line, B95-8. However, blocking Akt activity by expressing its dominant negative form remarkably promoted NaB and GCV-mediated cytotoxicity via a thymidine kinase (TK)-independent mechanism. Interestingly, it was found that the constitutive activation of mitogen-activated protein kinase kinase kinase 1 (MEKK1) dramatically enhanced the sensitization of the cells to the combination of NaB and GCV, accompanied with an increase in TK expression in B95-8 cells. These results suggest that interfering with either the Akt or MEKK1 signaling pathway may be a useful therapeutic strategy to increase the sensitivity of EBV-positive tumor cells to the combination of NaB and GCV.
[Show abstract][Hide abstract] ABSTRACT: To investigate the impact of phenotypic knockout of CXCR4 on Molt-4 cells via intrakine technology,the C-terminal alpha-helix gene SDF-1alpha/54/KDEL of human stromal cell-derived Faceor-1 deletion is fused to a retention signal 4-peptide -KDEL that retains the newly synthesized receptor within the Molt-4 cells endoplasimc reticulum. Subsequently, PCR is used to amplify the target gene SDF-1alpha/54/ KDEL from the constructed plasmid SDF-WT-Gly x 4-Dec/PET-30a(+) at its C-terminal and subclone it into eukaryotic expression vectors pEGFP-C3 for generating recombinant vector cells by lipEGFP-C3/SDF-1alpha/54/KDEL, and then have it sequenced. After the transfection of recombinant plasmids into COS-7 posome, SDF-1alpha/54/KDEL protein is confirmed with Western blot. The recombinant plasmids pEGFP-C3/SDF-1alpha/54/KDEL are isolated and transiently transfected in Molt-4 cells by electroporation. Flow cytometric analysis shows a dramatic reduction of CXCR4 expression on Molt-4 cells. The conclusion is that SDF-1alpha/54/KDEL could assume a role in the phenotypic knockout of CXCR4, and the findings suggest that the inhibiting effect of SDF-1alpha/54 against CXCR4 is not influenced by the deletion of SDF-1alpha helix at the C terminal.
No preview · Article · Jul 2008 · Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi
[Show abstract][Hide abstract] ABSTRACT: An albumin-binding prodrug of the extremely potent CC-1065 analog, (+)-FDI-CBI, has been synthesized. This analog, (+)-FDI-CBIM, formed an albumin conjugate when added to human albumin in vitro. A greater amount (>3-fold) of the prodrug can be administered to animals compared to the free drug. The prodrug had significantly improved antitumor efficacy compared to the free drug in animal models using syngeneic animal tumors and human ovarian xenografted tumor cells. Antitumor drug delivery by in situ formation of drug-albumin conjugate is a promising strategy to improve antitumor efficacy.
[Show abstract][Hide abstract] ABSTRACT: Dendritic cell (DC)-based cancer vaccines are currently being evaluated as novel anti-tumor vaccination strategies, but in some cases, they are demonstrated to have poor clinical efficacies than anticipated. A potential reason is immune tolerance due to the immunosuppressive enzyme, indoleamine-pyrrole 2,3-dioxygenase (IDO). The aim of this study was to determine whether blocking the activity of IDO might improve the anti-tumor efficacy of DC/Lewis lung carcinoma (LLC) fusion vaccine applied to the mouse LLC model.
To prepare the DC/LLC fusion vaccine, DCs were fused with LLC using polyethylene glycol (PEG) as described. The IDO expression in the DC/LLC fusion vaccine and in the vaccinated mice was detected by western blot (WB) and/or immunohistochemical (IHC) analysis. This fusion vaccine, as a single agent or in combination with 1-methyl-tryptophan (1-MT, an IDO inhibitor), was administered to LLC mice. The anti-tumor efficacy in different treatment was determined by regular observation of tumor development and the level of splenic cytotoxic T lymphocyte (CTL) response, which was examined by lactate dehydrogenase (LDH) release.
In the LLC mice, we observed that IDO-positive cells were extensively accumulated in tumor draining lymph nodes (TDLNs). Furthermore, WB and IHC analysis results showed that vaccination with fusion DC/LLC cells alone caused significant up-regulation of IDO in spleens. 1-MT enhanced the anti-tumor efficacy elicited by DC/LLC fusion vaccine via delaying the tumor development and inducing stronger splenic CTL responses.
Our results indicate an IDO-mediated immunosuppressive mechanism might be involved in weakening the anti-tumor efficacy elicited by DC/LLC fusion vaccine, and specific inhibition of IDO activity might be required for development of cancer vaccines.
No preview · Article · Jun 2008 · Journal of Cancer Research and Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Several studies have shown that the interaction of CXC chemokine receptor 4 (CXCR4) with its ligand, stromal cell-derived factor-1alpha (SDF-1alpha) is closely involved in the directional migration of some tumors toward specific organs, which provides a new pathway against cancer metastasis. We previously developed an alpha-helix-defective mutant of SDF-1alpha, SDF-1/54 that displays obvious antagonistic activity to CXCR4. But it is necessary to ensure the targeting of SDF-1/54 to tumors in vivo since many normal tissues also express CXCR4. It is known that most tumor cells highly express epidermal growth factor receptor (EGFR). Meanwhile, decorin (DCN), a specific antagonist of EGFR, can target the tumor cells enriched in EGFR and cause a significant downregulation of EGFR. Hereby, we further generated a fusion construct of SDF-1/54 and DCN to expect to enhance the targeting of SDF-1/54 to tumors by dual blocking effects on CXCR4 and EGFR. This study focused on expression of recombinant chimera SDF-1/54-DCN in Escherichia coli, purification and bioactivity to inhibit the physiological functions mediated by CXCR4 and EGFR respectively in various tumor cell lines in vitro. Results indicated that SDF-1/54-DCN could inhibit both chemotaxis and proliferation of the tumor cells we used, which may be attributed to its blocking to CXCR4 and EGFR. These findings suggest that this strategy to link SDF-1/54 with DCN may be a promising approach to increase the targeting of SDF-1/54 to the tumors coexpressing CXCR4 and EGFR.
No preview · Article · Jun 2008 · Biological & Pharmaceutical Bulletin