N-Acetyltransferase 2 (NAT2) is one of the most important polymorphic drug-metabolizing enzymes and plays a significant role in individual differences of drug efficacies and/or side effects. Coenzyme A (CoA) is a cofactor in the experimentally determined crystal structure of NAT2, although the acetyl source of acetylation reactions catalyzed by NAT is not CoA, but rather acetyl CoA. In this study, the three-dimensional structure of NAT2, including acetyl CoA, was calculated using molecular dynamics simulation. By substituting acetyl CoA for CoA the amino acid residue Gly286, which is known to transform into a glutamate residue by NAT2*7A and NAT2*7B, comes close to the cofactor binding site. In addition, the binding pocket around the sulfur atom of acetyl CoA expanded in the NAT2–acetyl CoA complex.
Membrane binding of Walker type adenosine 5′-triphosphate, adenosine triphosphatase (ATPase), MinD, is a key step in regulating the site of cell division in Escherichia coli. Two lysine residues (K11, K16) in the Walker A motif of MinD have been suggested to be essential for both membrane binding and ATPase activity, but the relationship between the membrane binding of MinD and its ATPase activity is still unclear. To reveal the role of K11 and K16 in MinD membrane interaction and ATP-binding, we compared the functionality of wild-type MinD (WT) and two MinD mutants that lack ATPase activity, where alanine was substituted for lysine at positions 11 and 16 (K11A, K16A), using liposomes and fluorescent-labeled ATP. The ATP dissociation constant (Kd) of wild-type MinD was 4.9 μM. Unexpectedly, the Kd values of the two lysine mutants were almost the same as that of wild type, indicating that ATP can bind to MinD mutants, even though these mutants showed no ATPase activity and membrane binding ability. Our results presumed that K11 and K16 residues might play an important role in dimmer formation of MinD, but not ATP binding step, for recruiting to membrane.
Berberine has a wide range of biochemical and pharmacologic effects, including antitumor activity, but the mechanisms involved in berberine-induced apoptosis remain unclear. The purpose of the present study was to investigate the changes in oxidative stress and endoplasmic reticulum (ER)-related molecules, which are closely associated with cell death-signaling transduction pathways, in human glioblastoma T98G cells treated with berberine. Berberine significantly decreased the cell viability of T98G cells in a dose-dependent manner. Berberine increased the production of reactive oxygen species (ROS) and level of intracellular Ca2+. Berberine induced ER stress as evidenced by the detection of ER stress-associated molecules such as phosphorylated protein kinase-like ER kinase, eukaryotic translation initiation factor-2α, glucose-regulated protein 78/immunoglobulin heavy chain-binding protein, and CCAAT/enhancer-binding protein (C/EBP)-homologous protein/growth arrest and DNA damage-inducible gene 153, which was associated with the activation of caspase-3. Furthermore, the administration of the antioxidants, N-acetylcysteine and glutathione, reversed berberine-induced apoptosis. Berberine also markedly enhanced apoptosis in T98G cells through the induction of a higher ratio of Bax/Bcl-2 proteins, disruption of the mitochondrial membrane potential, activation of caspase-9 and -3, and cleavage of the poly(ADP-ribose) polymerase (PARP). The inhibition of ER stress using salubrinal led to an increased the level of Bcl-2, whereas the level of Bax, cleavage of procaspase-9 and -3, and PARP were decreased when compared with cells treated with berberine alone, indicating that berberine-induced apoptosis is associated with mitochondrial dysfunction. These results demonstrate that berberine induces apoptosis via ER stress through the elevation of ROS and mitochondrial-dependent pathway in human glioblastoma T98G cells.
Many phytochemicals are known to exert cancer chemopreventive activity by eliminating chemical carcinogens or toxic xenobiotics through the action of detoxification enzymes. In this study, we investigated the cancer chemopreventive effects of youngiasides isolated from Crepidiastrum denticulatum. These youngiasides significantly induced quinone reductase (QR) activity in mouse hepatoma Hepa-1c1c7 cells, and showed a relatively high chemoprevention index (CI; divided IC50 value with CD value). The youngiasides also significantly induced transcriptional activation of QR in Hepa-QR-secreted alkaline phosphatase (SEAP) cells, which is a stable cell line containing the intact promoter region of QR. In order to determine if upregulation of QR by the youngiasides was mediated through a mono-functional or bi-functional mechanism, we examined the nuclear factor-E2 p45-related factor 2(Nrf2)-antioxidant response element (ARE) and aryl hydrocarbon receptor (AhR)-xenobiotic response element (XRE) pathways, which are two major pathways, involved in regulation of Phase I and/or Phase II detoxification enzymes. The youngiasides increased the cytochrome P450 1A1 (CYP1A1) mRNA and protein levels in human colorectal cancer Caco-2 cells and also increased the QR mRNA and protein levels in Caco-2 cells through ARE and XRE activation which resulted from translocation of Nrf2 and AhR into the nucleus. These results suggest that regulation of QR by the youngiasides was due to bi-functional induction through the Nrf2-ARE and AhR-XRE pathways. Thus, these youngiasides as bi-functional inducers of QR have potential as cancer chemopreventive agents.
Aminopeptidase N (APN) is a transmembrane metallopeptidase, which participates in the tumor progress such as proliferation, attachment, angiogenesis and tumor invasion. All of this makes APN as a good chemical therapeutic anti-tumor target. In the present study, we got a novel compound 16l which markedly inhibited the enzyme activity of porcine APN, and the inhibition constant, Ki, of 16l are similar to the positive medicine Bestatin determined using porcine APN. However, when tested using human tumor cells, 16l couldn't effectively inhibit the enzyme activity, cell viability, cell migration and invasion. Computer aided drug design verified that because of the difference in structure, the binding pattern of 16l in the active site of homo sapien and porcine APN was different. The compound 16l could effectively inhibit the enzyme activity of porcine APN, but not homo sapien APN located on the surface of tumor cells. Therefore, the activity screening of APN inhibitor using aminopeptidase N from porcine should be only preliminary determination. The real activity screening should be determined using homo sapien aminopeptidase N.
The cardiotoxicity of doxorubicin limits its clinical use in the treatment of a variety of solid tumors and malignant hematologic disease. Although the mechanism by which it causes cardiac injury is not yet known, apoptosis has been regarded as one of mechanisms underlying the cardiotoxic effects of doxorubicin. Eukaryotic translation initiation factor 5A (eIF5A) is a ubiquitously expressed multifunctional protein that interacts with a range of ligands and is implicated in cell signaling. However, there has been no direct evidence for the critical involvement of eIF5A in doxorubicin-induced apoptosis. Overexpression of eIF5A induced by doxorubicin in cardiomyocyte leads to growth perturbation along with initiation of apoptosis. Overexpression of eIF5A results in a gradual increase in reactive oxygen species (ROS) generation. This mitochondrial dysfunction is due to a gradual increase in ROS generation in eIF5A-overexpressing H9c2 cells. Along with ROS generation, increased Ca2+ influx in mitochondria leads to loss of the mitochondrial transmembrane potential, release of cytochrome-c, and caspase activation. However, small interfering RNA (siRNA)-mediated suppression of eIF5A results in inhibition of apoptosis. Interestingly, upon overexpression of eIF5A induced by doxorubicin, cell apoptosis was shown to be significantly inhibited when cells were treated with SB202190 (p38 mitogen-activated protein kinase inhibitor) and SP600125 (anti-c-Jun N-terminal kinase inhibitor) for 18 h. The reduction in oxidant generation and reduction in the apoptotic cell population were the results of the disruption of eIF5A expression, corroborating the hypothesis that excess ROS generation with overexpression of eIF5A induced by doxorubicin leads to apoptosis due to the accumulation of eIF5A.
We investigated the possible association of serotonin (5-HT) 2A receptor gene A-1438G polymorphism in Japanese patients with migraine. Genotyping of 5-HT2AA-1438G polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism in patients with migraine (male 17 : 3 with aura and 14 without aura, female 65 : 17 with aura and 48 without aura) and controls (male 31, female 84). The distribution of 5-HT2AA-1438G genotype frequency between migraine patients and controls did not differ. These results suggest that the A-1438G polymorphism of the 5-HT2A receptor gene is not a direct risk factor for migraine; however, the incidence of the A/A genotype between migraine with aura (MA) and without aura (MO) was significantly different. The 5-HT2AA-1438G polymorphism may be involved in determining the subtypes of migraine in Japanese.
In the present study, we successfully isolated a carrot leaf-derived lactic acid bacterium that produces gamma-aminobutyric acid (GABA) from monosodium L-glutamate (L-MSG) at a hyper conversion rate. The GABA-producing bacterium, identified as Enterococcus (E.) avium G-15, produced 115.7±6.4 g/l GABA at a conversion rate of 86.0±5.0% from the added L-MSG under the optimum culture condition by a continuous L-MSG feeding method using a jar-fermentor, suggesting that the bacterium displays a great potential ability for the commercial-level fermentation production of GABA. Using the reverse transcription polymerase chain reaction (RT-PCR) method, we analyzed the expression of genes for the GABA transporter and glutamate decarboxylase, designated gadT and gadG, respectively, which were cloned from the E. avium G-15 chromosome. Both genes were expressed even without the added L-MSG, but their expression was enhanced by the addition of L-MSG.
Gastrodin, a major bioactive component of a famous Chinese herb Gastrodia elata B1., has diverse pharmaceutical functions. It is usually obtained by extraction from a plant or through chemical synthesis. However, traditional extraction from Gastrodia elata B1. is time and money consuming, while chemical synthesis is a complicated procedure and always leads to very serious environmental pollution. Thus it is urgent to explore a new gastrodin source which is more economical and environmental. The present study reports a novel approach to the production of gastrodin through biosynthesis and microbial transformation. Rhizopus chinensis SAITO AS3.1165 was screened from about 50 fungal and bacterial strains and found capable of biotransforming p-hydroxybenzaldehyde into gastrodin for use in gastrodin production. A series of purification steps including (NH4)2SO4 precipitation, ion exchange chromatography and gel filtration column chromatography was successfully used for purification of the gastrodin biosynthesis enzyme (GBE). The purity of GBE was above 95% and its molecular weight was about 63.2 kDa. We further characterized GBE's function condition, and found that the optimal temperature was 50 °C and the optimum pH 6.0. The enzyme was stable at a temperature lower than 50 °C and a pH between 6.0 and 9.0. The result indicated that gastrodin could be successfully synthesized by microbial transformation, providing a new approach for gastrodin production.
α-Solanine, a naturally occurring steroidal glycoalkaloid in potato sprouts, was found to possess anti-carcinogenic properties, such as inhibiting proliferation and inducing apoptosis of tumor cells. However, the effect of α-solanine on cancer metastasis remains unclear. In the present study, we examined the effect of α-solanine on metastasis in vitro. Data demonstrated that α-solanine inhibited proliferation of human melanoma cell line A2058 in a dose-dependent manner. When treated with non-toxic doses of α-solanine, cell migration and invasion were markedly suppressed. Furthermore, α-solanine reduced the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9, which are involved in the migration and invasion of cancer cells. Our biochemical assays indicated that α-solanine potently suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), phosphatidylinositide-3 kinase (PI3K) and Akt, while it did not affect phosphorylation of extracellular signal regulating kinase (ERK). In addition, α-solanine significantly decreased the nuclear level of nuclear factor kappa B (NF-κB), suggesting that α-solanine inhibited NF-κB activity. Taken together, the results suggested that α-solanine inhibited migration and invasion of A2058 cells by reducing MMP-2/9 activities. It also inhibited JNK and PI3K/Akt signaling pathways as well as NF-κB activity. These findings reveal new therapeutic potential for α-solanine in anti-metastatic therapy.
The aim of the present study was to assess gender differences in diabetes-related vascular reactivity in murine aortas. Diabetes is a risk factor for ischemic heart disease, cerebral ischemia, and atherosclerosis, conditions in which endothelial dysfunction plays a pathogenetic role. We examined vascular responses in aortas isolated from streptozotocin (STZ)-induced type 1 diabetic mice and age-matched control mice, and looked for gender differences in the diabetes-induced changes in these responses. For each gender, the plasma adiponectin levels were lower in diabetic mice than in the controls, and they were significantly higher in females than in males. The acetylcholine (ACh)-induced endothelium-dependent relaxation of aortic rings was impaired (vs. that in the age-matched controls) in diabetic male mice, but not in diabetic female mice. The sodium nitroprusside-induced endothelium-independent aortic relaxation was not altered by diabetes in either male or female mice. The norepinephrine-induced aortic contraction was enhanced (vs. that in the control group) in diabetic female mice, but not in diabetic male mice, whereas in the presence of NG-nitro-L-arginine neither gender exhibited a significant diabetes-induced change in this contraction. The clonidine-induced and insulin-induced endothelium-dependent aortic relaxations were impaired only in the diabetic female group (vs. the age-matched controls). These results suggest that: a) in male diabetic mice, which exhibited low adiponectin levels, these were impairments of both the aortic relaxation and nitric oxide (NO) production induced by ACh, whereas b) in female diabetic mice, there were impairments of the aortic relaxations induced by both insulin and clonidine.
The present study examined modifications of β-naphthoflavone (β-NF)-induced cytochrome P450 1A1 (CYP1A1) expression by flavonoids in mouse hepatocytes in primary culture. Some flavonoids (apigenin, chrysin, flavone, flavanone, galangin, luteolin, and naringenin) by themselves induced CYP1A1 mRNA expression, especially flavone which was even more effective than β-NF. The effect on β-NF-induced CYP1A1 mRNA expression was varied, namely additive, suppressive, or both. An additive effect was observed after combined treatment with flavanone, naringenin, and chrysin, whereas kaempferol, myricetin, and quercetin decreased CYP1A1 levels. Apigenin, chrysin, galangin, luteolin, and morin synergistically enhanced β-NF-induced CYP1A1 expression at 24 h, but considerably suppressed it at 9 h. The structure–activity relationship of flavonoids affecting CYP1A1 expression as inducers or inhibitors is discussed. The present observations suggest the need to reveal the mechanism by which CYP1A1 expression is modified by flavonoids for risk assessment, since CYP1A1 activates environmental carcinogenic polycyclic hydrocarbons and flavonoids are major constituents in food.
Voltage-gated potassium (Kv) channels are expressed not only in excitable cells but also in non-excitable cells such as epithelial cells. Recent studies have demonstrated that several subtypes of Kv channels are expressed in epithelial tumor cells, including human gastric cancer cells, and are associated with cell proliferation. In the present study, we examined the expression of Kv4.1 in human gastric cancer cell lines and the effects of suppressed expression of Kv4.1 on cell proliferation and cell cycle distribution. We found that Kv4.1 mRNA and protein are expressed in the human gastric cancer cell lines MKN-45 and SNU-638. Moreover, Kv4.1-targeted small interference RNA (siRNA) treatment inhibited gastric cancer cell proliferation. Flow cytometric analysis revealed that suppressed expression of Kv4.1 induced a G1-S transition block of cell cycle progression. These results reveal that Kv4.1 plays a role in the proliferation of the human gastric cancer cell lines MKN-45 and SNU-638 and can be considered as a therapeutic target for human gastric cancer.
A series of benzo-annulated rutaecarpines were prepared from anthranilic acid and 3-aminonaphthalene-2-carboxylic acid by Fischer indole synthesis as key reaction. Cytotoxicity was somewhat increased by the introduction of benzo-annulation, which was not directly related to the inhibitory activity against topoisomerases (topo) I and II. Benzo-annulation on ring A led to significant increase of inhibitory activity against topo II while annulations on ring E increased inhibitory activity against topo I.
This study was performed to examine the effects of the antifibrotic agents TJN-331 and tranilast on mesangial expansion in a rat model of anti-Thy1 nephritis. We first investigated the effects of TJN-331 and tranilast on mesangial expansion induced by anti-Thy1 serum in rats, and determined the counts of glomerular cells and proliferative cell nuclear antigen (PCNA)-positive cells. The effects of TJN-331 and tranilast on production of transforming growth factor-β1 (TGF-β1) by isolated glomeruli incubated for 48 h were then examined. The TGF-β1 staining score, the number of TGF-β1-positive cells and the TGF-β1 receptor-positive area in the anti-Thy1 nephritis model were also measured using immunohistochemistry. TJN-331 administered from day 1 (the day after anti-Thy1 serum injection) blocked an increase in mesangial matrix accumulation on days 4 and 8, compared to untreated anti-Thy1 nephritic rats. TJN-331 also inhibited both the increase in the number of glomerular cells on day 8 and the decrease in this cell count on day 2 observed in untreated nephritic rats, and TJN-331 and tranilast inhibited an increase in PCNA-positive cells in the glomerular cross section on days 4 and 8. Both TJN-331 and tranilast inhibited increases in the TGF-β1 protein content from nephritic glomeruli, the TGF-β1-positive area, and the number of TGF-β1-positive cells/cross section in anti-Thy1 nephritic glomeruli. These results suggest that TJN-331 and tranilast prevent expansion of the mesangial area by suppression of TGF-β1 secretion from inflamed glomeruli.
New approaches to periodontal health have been in strong demand in addition to conventional local plaque control. In this study, liposomal bovine lactoferrin (L-bLF) was orally administered to subjects with periodontal disease to investigate whether it could be a useful treatment. L-bLF composed of soy phosphatidylcholine was given as a supplement for four weeks in tablet form (180 mg bLF/d) to twelve subjects with multiple sites of more than 3 mm probing depth (PD). PD, bleeding on probing (BOP), gingival crevicular fluid (GCF) volume and the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein-1 (MCP-1) in GCF were evaluated for 51 sites with more than 4 mm PD in five subjects. Blood samples of all subjects were collected 0, 2 and 4 weeks after supplementation. Isolated peripheral blood mononuclear cells (PBMCs) were incubated for 24 h with or without lipopolysaccharide (LPS) (100 ng/ml) from Porphyromonas gingivalis, and TNF-α, IL-1β, IL-6 and MCP-1 in the culture media were measured. Toll-like receptor 2 (TLR2) and TLR4 mRNA expressions of isolated PBMCs were also quantitatively analyzed using real-time reverse transcription-polymerase chain reaction (RT-PCR). The PD was significantly reduced by L-bLF supplementation, but the BOP and GCF volume were not significantly changed. The MCP-1 level in GCF was significantly reduced, while levels of other cytokines were not changed. Four-week L-bLF supplementation also showed significant decreases of LPS-induced cytokine production from PBMCs. Relative gene expressions of TLR2 and TLR4 did not change. These results suggest that L-bLF supplementation can be effective in the treatment of periodontal disease, although prospective controlled large-scale studies are required.
7-Hydroxy-6,8-dimethoxy-2H-1-benzopyran-2-one (isofraxidin) is a major coumarin component isolated from the stem bark of Acanthopanax senticosus, a widely used Chinese medicinal herb. We investigated isofraxidin in its anti-tumor effects on human hepatoma cell lines HuH-7 and HepG2. Isofraxidin significantly inhibited hepatoma cell invasion, without affecting cell attachment or growth. Expression of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced matrix metalloproteinase-7 (MMP-7) in hepatoma cells was inhibited by isofraxidin at the both mRNA and protein levels. This inhibition tended to be greater in cells inoculated at low density than in those at high density. Isofraxidin showed an inhibitory effect on the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in hepatoma cells, whereas activator protein-1 (AP-1) DNA binding activity, nuclear factor-kappa B (NF-κB) nuclear translocation, and inhibitory kappa B (IκB) degradation were affected very little. These results indicate that isofraxidin inhibits expression of MMP-7 and in vitro cell invasion at a non-toxic level through inhibiting ERK1/2 phosphorylation in hepatoma cell lines, which suggest isofraxidin might become an effective agent for suppressing hepatoma cell invasion.
The genus Phyllanthus (Phyllanthaceae) is distributed in tropical and subtropical regions, and its members are widely used as medicinal plants in many countries. We analyzed the nucleotide sequences of the internal transcribed spacers of ribosomal DNA of 56 plant samples covering 23 Phyllanthus species collected from various habitats in Thailand. Based on the sequence alignment, we constructed phylogenetic trees of all Phyllanthus species distributed in Thailand. Furthermore, a simple protocol to discriminate three important medicinal Phyllanthus species, P. amarus, P. debilis, and P. urinaria, was developed using a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism method and successfully applied to the crude drug samples obtained in Thai markets.
Cinobufacini (Huachansu) is a Chinese medicine prepared from the skin of Bufo bufo gargarizans Cantor (Bufonidae), which has long been used in traditional Chinese medicine (TCM). The aim of present study was to examine the anti-hepatitis B virus (HBV) activities of cinobufacini and its active components bufalin and cinobufagin in the human HBV-transfected cell line HepG2.2.15. The hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B core-related antigen (HBcrAg) concentrations in cell culture medium were determined by chemiluminescent enzyme immunoassay after HepG2.2.15 cells were respectively treated with different concentrations of cinobufacini, bufalin, and cinobufagin for 3 or 6 d. HBV DNA and mRNA were determined using transcription-mediated amplification and real-time polymerase chain reaction (PCR), respectively. On d 3, cinobufacini at a concentration of 1 μg/ml had no activity against HBV virological markers. However, on d 6, cinobufacini at 1 μg/ml effectively inhibited the secretion of HBsAg, HBeAg, and HBcrAg by 29.58, 32.87, and 42.52%. It was more potent than the positive control lamivudine (100 μg/ml). Bufalin and cinobufagin slightly inhibited HBV antigen secretion. Treatment with cinobufacini, bufalin, or cinobufagin had no anti-HBV effect on DNA in cell culture medium. Consistent with the HBV antigen reduction, HBV mRNA expression was markedly inhibited in comparison to the control when HepG2.2.15 cells were treated with cinobufacini, bufalin, or cinobufagin. Results suggested that cinobufacini had more potent activity against HBV antigen secretion than its components bufalin and cinobufagin and this inhibitory role was attributed to the specific inhibition of HBV mRNA expression.
Osteoclasts are the only cell type capable of resorbing mineralized bone, and they act under the control of numerous cytokines produced by supporting cells such as osteoblasts and stromal cells. Among cytokines, receptor activator of nuclear factor-κB ligand (RANKL) was found to be a key osteoclastogenetic molecule that directly binds to its cognate receptor, RANK, on osteoclast precursor cells. In turn, RANKL, which is an essential factor for differentiation and activation of osteoclasts, is one of the major targets of anti-resorptive agents. In this study, we found that palmatine, an isoquinoline alkaloid originally isolated from Coptis chinensis, had an inhibitory effect on osteoclast differentiation and function in vitro. Palmatine inhibited osteoclast formation in the co-culture system with mouse bone marrow cells (BMC) and osteoblasts in the presence of 10 nM 1α,25-(OH)2D3. Palmatine did not affect osteoclast formation induced by RANKL in the BMC cultures. Reverse-transcription polymerase chain reaction (RT-PCR) analysis showed that palmatine significantly inhibited the expression of 1α,25-(OH)2D3-induced expression of RANKL mRNAs in stromal cells without loss of cell viability. Moreover, palmatine suppressed resorption pit formation by mature osteoclasts on dentin slices and induced disruption of actin ring formation in mature osteoclasts with an impact on cell viability. Taken together, these results suggest that palmatine attenuates osteoclast differentiation through inhibition of RANKL expression in osteoblast cells, and its inhibitory effect on bone resorption is due to its disruptive effect on actin rings in mature osteoclasts. Therefore, palmatine might be an ideal candidate as an anti-resorptive agent for the prevention and treatment of bone disorders such as osteoporosis.
Tulobuterol patches are long-acting bronchodilators for percutaneous absorption including the β2-adrenoreceptor agonist tulobuterol, as a main ingredient, used for long-term management of pediatric asthma. Since patients who have pediatric asthma often also have atopic dermatitis in which the skin barrier is impaired, we compared the skin penetration profiles of the brand and generic patches using a skin barrier-impaired rat model. Skin penetration was significantly (p<0.001) higher in the generic patches compared with the brand patch, suggesting that it is important to understand the pharmaceutical properties of available products by giving careful consideration not only to the patient's asthma control but also to their skin condition before using tulobuterol patches.
Targeted gene delivery to cancer cells is considered as a promising strategy for cancer therapy. Since, several targeting ligands have been studied for cancer gene therapy, such as transferrin, folate, anisamide, RGD-peptide, and antibodies. We have focused on AG73 peptide, which is derived from the globular domain of the laminin α1 chain. AG73 peptide is known as a ligand for syndecans, one of the major heparin sulfate-containing transmembrane proteoglycans. Syndecan-2 is highly expressed in various cancer cells and plays a role in angiogenesis. In this study, we prepared AG73-labeled polyethyleneglycol-modified liposomes (AG73-PEG liposomes) for gene delivery tool to syndecan-2 overexpressing cancer cells, and assessed the characterization of AG73-PEG liposomes. We confirmed the conjugation of AG73 peptide to PEG liposomes by reverse-phase high-performance liquid chromatography analysis. Electron microscopy analysis showed that monodiseperse AG73-labeled lipsomes were prepared. We also assessed the gene transfection efficiency of AG73-PEG liposomes in syndecan-2 overexpressing cancer cells or syndecan-2 less expressing cancer cells. As a result, AG73-mediated liposomal gene transfection efficiency was increased by 100-fold in syndecan-2 overexpressing cancer cells compared to syndecan-2 less expressing cancer cells. These results suggested that AG73-PEG liposomes were successfully prepared from a point of view of the modification of AG73 peptide to PEG-liposomes and the particle size of liposomes, which presented nano size. Furthermore, our results suggest that AG73-PEG liposomes can be a useful targeted gene delivery vehicle for syndecan-2 overexpressing cancer cells.
Matrine, an alkaloid extracted from a Chinese herb, Sophora flavescens AIT., has exhibited anti-proliferative and pro-apoptotic abilities against various types of cancer cells. This study aims to investigate its anti-cancer activity and underlying mechanisms in human pancreatic cancer cells in vitro and in vivo. Human BxPC-3 and PANC-1 pancreatic cancer cells, and human HL-7702 liver cells were incubated with matrine at different concentrations. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell apoptosis, by flow cytometry. Subcutaneous BxPC-3 xenograft tumors were established in nude BALB/c mice, and matrine was intraperitoneally (i.p.) administered. The tumors were monitored and harvested. Tumor sections were immunostained with an anti-Ki-67 antibody (Ab) to examine cell proliferation, or stained with terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) to evaluate in situ cell apoptosis. The expression of proliferating cell nuclear antigen (PCNA) and several apoptosis-related proteins in cells and tumor tissues were evaluated by Western blot analysis. In in vitro assays, matrine inhibited cell viability by downregulating the expression of PCNA, and induced cell apoptosis by reducing the ratio of Bcl-2/Bax, upregulating Fas, and increasing activation of caspases-8,-3 and -9, in a dose-dependent manner. Administration of matrine inhibited tumor growth in a dose-dependent manner, and regulated tumoral gene expression consistent with the in vitro results. But matrine had no significant effects on the viability of HL-7702 cells or the bodyweight of mice compared to controls. These results indicate matrine may be a potential and promising agent of natural resource to treat pancreatic cancer.