Anti-psoriatic effects of Honokiol through the inhibition of NF-κB and VEGFR-2 in animal model of K14-VEGF transgenic mouse.

Honokiol (HK), a biphenolic neolignan isolated from Magnolia officinalis, has been reported to possess anti-inflammatory and anti-angiogenic activaties. In this study, our aim was to investigate anti-psoriatic activities of HK and the involved mechanisms. In vitro, the effects of HK on the regulation of Th1/Th2 and TNF-α-induced NF-κB (p65) activation were analyzed by respective FCS and immunofluorescence. Additionally, the K14-VEGF transgenic model was used for the in vivo study. ELISA and Q-PCR were performed to evaluate serum levels of Th1/Th2 cytokines and their corresponding mRNA expressions. Effects on VEGFR-2 and p65 activation, as well as other angiogenic and inflammatory parameters were studied by immunostainings. Importantly, we found that HK significantly decreased the ratio of Th1/Th2-expression CD4(+) T cells and inhibited TNF-α-induced activation of NF-κB. The morphology and histological features of psoriasis were effectively improved by HK treatment. The expression of TNF-α and IFN-γ, and their corresponding mRNA levels were down-regulated and the expression of nuclear p65, VEGFR-2, as well as related phosphorylated proteins (p-VEGFR-2, p-ERK1/2, p-AKT and p-p38) were also suppressed. Overall, these results in our study suggested that HK exhibits anti-psoriatic effects through the inhibition of NF-κB and VEGFR-2.

Cyclodextrin-Based Polymeric Drug Delivery Systems for Cancer Therapy.

Cyclodextrins (CDs) are one of the most extensively studied cyclic-oligosaccharides due to their low toxicity, good biodegradability and biocompatibility, facile chemical modification, and unique inclusion capacity. However, problems such as poor pharmacokinetics, plasma membrane disruption, hemolytic effects and a lack of target specificity still exist for their applications as drug carriers. Recently, polymers have been introduced into CDs to combine the advantages of both biomaterials for the superior delivery of anticancer agents in cancer treatment. In this review, we summarize four types of CD-based polymeric carriers for the delivery of chemotherapeutics or gene agents for cancer therapy. These CD-based polymers were classified based on their structural properties. Most of the CD-based polymers were amphiphilic with the introduction of hydrophobic/hydrophilic segments and were able to form nanoassemblies. Anticancer drugs could be included in the cavity of CDs, encapsulated in the nanoparticles or conjugated on the CD-based polymers. In addition, the unique structures of CDs enable the functionalization of targeting agents and stimuli-responsive materials to realize the targeting and precise release of anticancer agents. In summary, CD-based polymers are attractive carriers for anticancer agents.

Redox-responsive self-assembled podophyllotoxin twin drug nanoparticles for enhanced intracellular drug delivery.

Podophyllotoxin (PPT) is an active natural pharmaceutical component with potent anticancer activity. However, due to its poor water solubility and serious side effects, its medical applications are limited. In this work, we synthesized a series of PPT dimers, which can be self-assembled into stable nanoparticles of 124-152 nm in aqueous solution and can significantly increase the solubility of PPT in aqueous solution. In addition, PPT dimer nanoparticles exhibited high drug loading capacity (>80%) and could store at 4 °C in aqueous state with good stability for at least 30 d.In vitrorelease studies showed that nanoparticles with disulfide bonds (SS NPs) can quickly release (about 96.5% drug released within 24 h) the conjugated drug in PBS buffer (pH = 7.4) in the presence of DTT. Cell endocytosis experiments showed that SS NPs enhanced cell uptake (18.56 times higher than PPT for Molm-13, 10.29 times for A2780S and 9.81 times for A2780T) and maintained antitumor effect against human ovarian tumor cells (A2780S and resistant A2780T) and human breast cancer cells (MCF-7). In addition, the endocytosis mechanism of SS NPs was revealed that these nanoparticles were mainly up-taken by macropinocytosis-mediated endocytosis. We believe that these PPT dimer-based nanoparticles will become an alternative formula for PPT, moreover the assembly behavior of PPT dimer can be extended to other therapeutic drugs.

Synthesis and antiangiogenic activity of novel gambogic acid derivatives.

Gambogic acid (GA) is in a phase II clinical trial as an antitumor and antiangiogenesis agent. In this study, 36 GA derivatives were synthesized and screened in a zebrafish model to evaluate their antiangiogenic activity and toxicity. Derivatives 4, 32, 35, 36 effectively suppressed the formation of newly grown blood vessels and showed lower toxicities than GA as evaluated by zebrafish heart rates and mortalities. They also exhibited more potent migration and HUVEC tube formation inhibiting activities than GA. Among them, 36 was the most potent one, suggesting that it may serve as a potential new antiangiogenesis candidate with low toxicity. Additionally, 36 showed comparable antiproliferative activity to HUVECs and five tumor cell lines but low cytotoxicity to LO2 cells.

An ultra-performance LC-MS/MS method for determination of JRF103 in human plasma: application in first in-patient study.

Background: JRF103, a novel pan-HER inhibitor, has shown potent activity against HER1, HER2, HER4 and EGFR in vitro. To support its first in-patient trial, a sensitive and rapid method was developed and validated using ultra-performance LC-MS/MS. Materials & methods: JRF103 was extracted from plasma using protein precipitation. Extracts were subjected to ultra-performance LC-MS/MS with electrospray ionization. Results: Separation of analyte was achieved using a 1.7-µm C18 column (2.1 × 50-mm internal diameter) with a gradient elution. The developed method was fully validated following the international guides. Conclusion: The developed method was sensitive, specific and suitable for measuring JRF103 concentration in patients with advanced solid tumors in the first in-patient study of JRF103.

A size-shrinkable matrix metallopeptidase-2-sensitive delivery nanosystem improves the penetration of human programmed death-ligand 1 siRNA into lung-tumor spheroids.

Given the maturation of small-interfering RNA (siRNA) techniques with nanotechnology, and because overexpression of human programmed death-ligand 1 (PD-L1) is crucial for T cell inactivation and immunosuppression of the tumor microenvironment, application of siRNA-PD-L1 has demonstrated positive progress in preclinical studies; however, the limited penetration of this compound into solid tumors remains a challenge. To decrease PD-L1 expression and increase the penetration efficacy of solid tumors, we synthesized a novel tumor-microenvironment-sensitive delivery polymer by conjugating hyaluronic acid (HA) to polyethyleneimine (PEI), with a matrix metalloproteinase-2 (MMP-2)-sensitive peptide acting as the linker (HA-P-PEI), for use in delivery of PD-L1-siRNA. Concurrent synthesis of a linker-less HA-PEI compound allowed confirmation that negatively charged siRNA can be complexed onto the positively charged HA-PEI and HA-P-PEI compounds to form nanoparticles with the same particle size and uniform distribution with serum stability. We found that the size of the HA-P-PEI/siRNA nanoparticles decreased to <10 nm upon addition of MMP-2, and that H1975 cells overexpressing CD44, PD-L1, and MMP-2 aided confirmation of the delivery efficacy of the HA-P-PEI/siRNA nanocomplexes. Additionally, the use of HA-P-PEI caused less cytotoxicity than PEI alone, demonstrating its high cellular uptake. Moreover, pretreatment with MMP-2 increased nanocomplex tumor permeability, and western blot showed that HA-P-PEI/PD-L1-siRNA efficiently downregulated the PD-L1 expression in H1975 cells. These results demonstrated a novel approach for siRNA delivery and tumor penetration for future clinical applications in cancer treatment.

Preparation, characterization and biological evaluation of ß-cyclodextrin-biotin conjugate based podophyllotoxin complex.

Podophyllotoxin is a natural occurring aryltetralin lignin with pronounced cytotoxic activity. However, its clinical application for cancer treatment has been blocked due to its poor water solubility and selectivity. In this work, biotin as a tumor specific ligand was coupled with ß-cyclodextrin and the resulting biotin modified ß-cyclodextrin was used to complex with podophyllotoxin to improve its aqueous solubility and tumor selectivity. The solubility of ß-cyclodextrin was greatly enhanced(>16 times) by conjugating with biotin. podophyllotoxin/ mono-6-biotin-amino-6-deoxy-ß-cyclodextrin inclusion complex was prepared by freeze-drying method and the complex behavior between mono-6-biotin-amino-6-deoxy-ß-cyclodextrin and podophyllotoxin was studied by water solubility, phase solubility, Job's plot, UV spectroscopy, Proton Nuclear Magnetic Resonance, Rotating-frame Overhauser Effect Spectroscopy, Powder X-ray diffraction and Scanning electron microscopy. The solubility of podophyllotoxin/ mono-6-biotin-amino-6-deoxy-ß-cyclodextrin complex was greatly improved(9 times) compared with Podophyllotoxin. The stability constant of podophyllotoxin/ mono-6-biotin-amino-6-deoxy-ß-cyclodextrin complex (Ks= 415.29 M-1) was 3.2 times that of podophyllotoxin/ß-cyclodextrin complex. The possible inclusion mode of podophyllotoxin/mono-6-biotin-amino-6-deoxy-ß-cyclodextrin complex was inferred from the Proton Nuclear Magnetic Resonance and Rotating-frame Overhauser Effect Spectroscopy. The cellular uptake study showed that the introduction of biotin increased the cellular uptake of rhodamine-B/mono-6-biotin-amino-6-deoxy-ß-cyclodextrin complex. Moreover, cell cytotoxicity study showed that the antitumor activity of podophyllotoxin/ mono-6-biotin-amino-6-deoxy-ß-cyclodextrin complex was more potent than podophyllotoxin/ß-cyclodextrin complex and free podophyllotoxin. The superior water solubility and enhanced cytotoxicity suggested that the mono-6-biotin-amino-6-deoxy-ß-cyclodextrin associated inclusion complex might be a potential and promising delivery system for hydrophobic chemotherapeutics such as podophyllotoxin.

Antitumor Effects of Docetaxel in Truncated Basic Fibroblast Growth Factor- Functionalized Liposomes Delivered by d-α-tocopheryl Polyethylene Glycol 2000 Succinate.

BACKGROUND: PEGylation of stealth liposomes elevates their stability and prolongs plasma half-life. Stealth liposomes modified with targeting ligands are expected to be ideal drug delivery carriers. OBJECTIVE: To encapsulate docetaxel in tbFGF (truncated basic fibroblast growth factor)-functionalized liposomes with mPEG2000-VE (d-κ-tocopheryl polyethylene glycol succinate, TPGS2K) and measure their antitumor effects in vitro and in vivo. METHODS: TPGS2K and COOH-PEG2000-VE were synthesized, and tbFGF was conjugated to COOH-PEG2000-VE to prepare tbFGF-PEG2000-VE. Then, tbFGF-functionalized liposomes (DTX-tbFGF-LPs) were prepared by inserting tbFGF-PEG2000-VE into docetaxel liposomes comprising TPGS2K (DTX-PEG-LPs). The stabilities and drug release profiles of the formulation were evaluated. P-glycoprotein (P-gp) inhibition was measured by ATPase assay. MTT and cell uptake were measured with B16 cells. A B16 C57BL/6 mouse model was used to evaluate in vivo antitumor efficacy. RESULTS: Both DTX-PEG-LPs and DTX-tbFGF-LPs exhibited good stability and sustained drug release. MTT, flow cytometry, and fluorescence microscopy of B16 cells revealed higher antitumor activity and more efficient cell uptake for DTX-tbFGF-LPs compared with DTX-PEG-LPs and DTX-LPs. The P-gp ATPase assay showed that both PEG-LP and tbFGF-PEG-LP formulations inhibited P-gp pump activity in vitro. DTX-tbFGF-LPs had the highest antitumor efficacy and lowest toxicity in vivo. CONCLUSION: Truncated basic fibroblast growth factor-functionalized liposomes with TPGS2K as drug delivery nanocarriers were effective chemotherapy agents targeting FGFR-overexpressing tumors.

5-(4-Chloro-anilinomethyl-ene)-2,2-dimethyl-1,3-dioxane-4,6-dione.

The title compound, C(13)H(12)ClNO(4), is approximately planar, with a dihedral angle of 8.23 (4)° between the mean plane of the amino-methyl-ene unit and the planar part of the dioxane ring. The dioxane ring has a half-boat conformation, in which the C atom between the dioxane O atoms is -0.464 (8) Šout of the plane of the other five atoms. In the mol-ecule there is an intra-molecular N-H⋯O hydrogen bond, involving the NH H atom and the adjacent dioxane carbonyl O atom. In the crystal, weak intermolecular C-H⋯O hydrogen-bonding contacts, result in the formation of sheets parallel to the ab plane.

Synthesis of Dibenzofurans from Cyclic Diaryliodonium Triflates and Water via Oxygen-Iodine Exchange Approach.

An efficient synthesis of a variety of dibenzofuran derivatives via Cu-catalyzed cyclization diaryliodonium salts in water is achieved. Various dibenzofuran derivatives could be obtained in good to excellent yields via this oxygen-iodine exchange approach. A concise synthesis of organic semiconducting material molecule has been achieved using this method.

Preparation, Characterization, and In Vivo Study of 7-Ethyl-14-Aminocamptothecin-Loaded Poly(Ethylene Glycol)2000 -Poly(Lactic Acid)2000 Polymeric Micelles Against H460 Human Nonsmall Cell Lung Carcinoma.

This work aims to improve the solubility of 7-ethyl-14-aminocamptothecin (EACPT) by encapsulating it into monomethoxy poly(ethylene glycol)2000 -poly(lactic acid)2000 (MPEG-PLA) polymeric micelles. Micelles were prepared by a solid dispersion method; the properties including particle size distribution, morphology, drug loading, entrapment efficiency, crystallography property, solubility, and stability were characterized in detail. The results demonstrated that the EACPT-loaded MPEG-PLA polymeric micelle (EACPT-M) was successfully developed with a small particle size of 20.7 ± 0.2 nm, and the solubility was increased approximately 800-fold compared with free drug. In vitro release study showed sustained-release behavior of EACPT-M. Cytotoxicity assay suggested the incorporated EACPT maintained the potent antitumor effect of free drug. Furthermore, the obtained EACPT-M (1 mg/mL) did not induce hemolysis in vitro. Additionally, EACPT-M exhibited significant tumor growth inhibition in H460 human tumor xenograft model. The results indicated that the EACPT-M was a water-soluble, safe, and effective delivery system for human cancer chemotherapy.

Characterization of metabolic profile of honokiol in rat feces using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry and (13)C stable isotope labeling.

As fecal excretion is one of important routes of elimination of drugs and their metabolites, it is indispensable to investigate the metabolites in feces for more comprehensive information on biotransformation in vivo. In this study, a sensitive and reliable approach based on ultra-performance liquid chromatography/quadrupole-time-of-flight-mass spectrometry (UHPLC-Q-TOF-MS) was applied to characterize the metabolic profile of honokiol in rat feces after the administration of an equimolar mixture of honokiol and [(13)C6]-labeled honokiol. Totally 42 metabolites were discovered and tentatively identified in rat feces samples, 26 metabolites were first reported, including two novel classes of metabolites, methylated and dimeric metabolites of honokiol. Moreover, this study provided basic comparative data on the metabolites in rat plasma, feces and urine, which gave better understanding of the metabolic fate of honokiol in vivo.

Gambogic acid exhibits anti-psoriatic efficacy through inhibition of angiogenesis and inflammation.

BACKGROUND: Psoriasis is a chronic T cell-mediated inflammatory skin disease. Studies have shown that angiogenesis plays an important role in the pathogenesis of psoriasis. Studies have also indicated that Gambogic acid (GA) inhibits angiogenesis and may be a viable drug candidate in anti-angiogenesis therapies. OBJECTIVE: The aim of this study was to investigate the anti-psoriatic effect of GA and the possible mechanisms. METHODS: MTT test on HaCaT cells and immunofluorescence on HUVEC cells were processed. An O/W cream of GA was prepared and topically applied to the ears of K14-VEGF transgenic mice and psoriasis-like guinea-pigs, and the tail skin of Balb/C mice independently. Furthermore, hematoxylin-eosin staining of tissues from three models and immunohistochemistry staining of ear samples from K14-VEGF mice were performed. RESULTS: In vitro, GA inhibited proliferation of HaCaTs and TNF-α-induced activation of NF-κB in HUVECs. In vivo, animals treated with GA showed significant morphological and histological improvements. Immunohistochemical analysis of K14-VEGF transgenic mice revealed that hyperplastic and inflamed vessels were suppressed with GA treatment. The expression of adhesion molecules such as ICAM-1 and E-selectin was significantly decreased. GA inhibited angiogenesis and the expression of VEGFR2 and p-VEGFR2. T lymphocyte infiltration and the expression of IL-17 and IL-22 were also reduced by GA treatment. CONCLUSION: Our results suggest that GA has anti-psoriatic efficacy through inhibition of angiogenesis and inflammation. Therefore, GA is attractive and offers future potential for application in patients with psoriasis.

Inclusion complex of barbigerone with hydroxypropyl-ß-cyclodextrin: preparation and in vitro evaluation.

The aim of this study was to improve the water solubility of barbigerone by complexing it with hydroxypropyl-ß-cyclodextrin (HP-ß-CD). The inclusion complexation behavior, characterization and interactions of barbigerone with HP-ß-CD were investigated in both solution and the solid state by means of UV/VIS, (1)H NMR, FT-IR, PXRD, SEM. All the characterization information demonstrated the formation of barbigerone-HP-ß-CD (bar-HP-ß-CD) inclusion complex, and the bar-HP-ß-CD inclusion compounds exhibited different spectroscopic features and properties from barbigerone. The results demonstrated that the water solubility of barbigerone was notably increased in the presence of HP-ß-CD. Furthermore, preliminary in vitro cytotoxicity assay showed that bar-HP-ß-CD still maintain the anticancer activity of barbigerone. These results suggest that HP-ß-CD will be potentially useful in the delivery of water-insoluble anticancer agents such as barbigerone.

Improving aqueous solubility and antitumor effects by nanosized gambogic acid-mPEG2000 micelles.

The clinical application of gambogic acid, a natural component with promising antitumor activity, is limited due to its extremely poor aqueous solubility, short half-life in blood, and severe systemic toxicity. To solve these problems, an amphiphilic polymer-drug conjugate was prepared by attachment of low molecular weight (ie, 2 kDa) methoxy poly(ethylene glycol) methyl ether (mPEG) to gambogic acid (GA-mPEG2000) through an ester linkage and characterized by (1)H nuclear magnetic resonance. The GA-mPEG2000 conjugates self-assembled to form nanosized micelles, with mean diameters of less than 50 nm, and a very narrow particle size distribution. The properties of the GA-mPEG2000 micelles, including morphology, stability, molecular modeling, and drug release profile, were evaluated. MTT (3-(4,5-dimethylthiazo l-2-yl)-2,5 diphenyl tetrazolium bromide) tests demonstrated that the GA-mPEG2000 micelle formulation had obvious cytotoxicity to tumor cells and human umbilical vein endothelial cells. Further, GA-mPEG2000 micelles were effective in inhibiting tumor growth and prolonged survival in subcutaneous B16-F10 and C26 tumor models. Our findings suggest that GA-mPEG2000 micelles may have promising applications in tumor therapy.

Identification of metabolites of honokiol in rat urine using 13C stable isotope labeling and liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry.

A general approach based on stable isotope labeling and UPLC/Q-TOF-MS analysis of in vivo novel metabolites of honokiol has been developed in our study. In this method, urine samples were collected after intravenous administration of mixture of regular and [(13)C6]-labeled honokiol at 1:1 ratio to healthy rats. The metabolites could be easily recognized by the determination of a chromatographically co-eluted pair of isotopomers (MS doublet peaks) with similar peak intensities and mass difference corresponding to that between isotope-labeled and non-isotope-labeled honokiol. A total of 51 metabolites were detected, 37 of which were tentatively identified based on mass accuracy (<5 ppm). Among them, 33 of honokiol metabolites were first reported with 5 metabolites belonging to phase I and other 32 metabolites belonging to phase II metabolites. Our results highlighted that the main phase I metabolic pathways of honokiol in rats were oxidation, and the phase II metabolic pathways were sulfation, glucuronidation, acetylation as well as amino acids conjugation. This was the first research focused on the biotransformation of honokiol in rats, and the identification of these metabolites might provide us essential information for further pharmacological and clinical studies of honokiol.

Identification of honokiol metabolites in rats by the method of stable isotope cluster technique and ultra-high performance liquid chromatography/quadrupole-time-of-flight mass spectrometry.

Honokiol, a natural molecule isolated from Magnolia officinalis Rehd. et Wils., is widely known as an antitumor agent. In present work, an analysis of in vivo biotransformation and metabolites of honokiol has been performed by a combined method based on stable isotope cluster technique with honokiol-[(13)C6]-labeled and ultra-high performance liquid chromatography/quadrupole-time-of-flight-mass spectrometry (UHPLC/Q-TOF-MS). The metabolites could be easily identified by the determination of a chromatographically co-eluted pair of isotopomers (MS doublet peaks) with similar peak intensities and mass difference corresponding to that between isotope-labeled and non-isotope-labeled honokiol. A total of eighteen metabolites were detected and tentatively identified, fourteen of which were reported for the first time. The results indicated that the main metabolic pathways of honokiol in rats were hydroxylation, methylation, sulfation and glucuronidation. This study provided the first essential information on biotransformation and metabolites of honokiol in rats, which was very useful for further pharmacological and clinical studies of honokiol as a potent drug candidate.

Peptide ligand and PEG-mediated long-circulating liposome targeted to FGFR overexpressing tumor in vivo.

BACKGROUND AND METHODS: Paclitaxel, a widely used antitumor agent, has limited clinical application due to its hydrophobicity and systemic toxicity. To achieve sustained and targeted delivery of paclitaxel to tumor sites, liposomes composed of egg phosphatidylcholine, cholesterol, and distearolyphosphatidyl ethanolamine-N-poly(ethylene glycol) (PEG(2000)) were prepared by a lipid film method. In addition, the liposomes also contained truncated fibroblast growth factor fragment-PEG-cholesterol as a ligand targeting the tumor marker fibroblast growth factor receptor. Physicochemical characteristics, such as particle size, zeta potential, entrapment efficiency, and release profiles were investigated. Pharmacokinetics and biodistribution were evaluated in C57BL/6 J mice bearing B16 melanoma after intravenous injection of paclitaxel formulated in Cremophor EL (free paclitaxel), conventional liposomes (CL-PTX), or in targeted PEGylated liposomes (TL-PTX). RESULTS: Compared with CL-PTX and free paclitaxel, TL-PTX prolonged the half-life of paclitaxel by 2.01-fold and 3.40-fold, respectively, in plasma and improved the AUC(0→t) values of paclitaxel by 1.56-fold and 2.31-fold, respectively, in blood. Biodistribution studies showed high accumulation of TL-PTX in tumor tissue and organs containing the mononuclear phagocyte system (liver and spleen), but a considerable decrease in other organs (heart, lung, and kidney) compared with CL-PTX and free paclitaxel. CONCLUSION: The truncated fibroblast growth factor fragment-conjugated PEGylated liposome has promising potential as a long-circulating and tumor-targeting carrier system.

Design, synthesis and biological evaluation of thiazole- and indole-based derivatives for the treatment of type II diabetes.

Present studies have shown that the lipid carrier has a significant role in several aspects of metabolic syndrome in A-FABP/ap2-deficient mice, including type 2 diabetes and atherosclerosis. 38 Thiazole- and indole-based derivatives were synthesized and investigated for their inhibitory effects on the production of LPS-stimulated TNF-α. Among them, 12b exhibited an excellent inhibitory efficiency compared to BMS309403 (95% vs. 85%) at the concentration of 10 µM and a binding affinity for ap2 with the apparent K(i) values 33 nM. Oral administration of 12b at a dosage of 50 mg/kg effectively reduced the levels of plasma blood glucose, triglycerides, insulin, total cholesterol and alanine aminotransferase in high-fat/diet-induced obesity model. The results highlighted that 12b was a potent anti-diabetic agent.

Design, synthesis, and structure-activity relationship studies of novel millepachine derivatives as potent antiproliferative agents.

In this paper, 38 millepachine derivatives have been designed, synthesized and evaluated for their in vitro and in vivo antiproliferative activity. Among these novel derivatives, 15 displayed more potent antiproliferative activity than millepachine against HepG2, K562, SK-OV-3, HCT116, HT29, and SW620 tumor cells (mean IC(50) = 0.64 vs. 2.86 µM, respectively). Furthermore, 15 could effectively inhibit tubulin polymerization in HepG2 cells, and induce the HepG2 cell cycle arrest at the G2/M phase in a concentration-dependant manner. Further studies confirmed that 15 significantly suppressed the growth of tumor volume and exerted more potent anticancer potency than millepachine and anticancer drug cisplatin in A549 lung xenograft tumor model.