新穎奈米微粒載體於抗癌藥物傳遞的研究

[[abstract]]奈米藥物輸遞系統可藉由改變藥物在人體內的分佈，達到高度靶向、控制藥物釋放、提高難溶藥物的溶解率及吸收率，增加藥效及減少藥物毒性等目的。本研究以聚麩胺酸或三聚磷酸鈉 (sodium tripolyphosphate) 與小分子量幾丁聚醣經由離子凝膠法(ionic gelation process)製備奈米粒子，作為抗癌藥物傳遞載體。比較由不同去乙醯度、分子量的幾丁聚醣所製成奈米粒子特性的差異，並觀察其對抗癌藥物Doxorubicin 與Paclitaxel 包覆率及體外釋放速率的影響。 本計畫擬於三年內完成。第一年主要對所製備的奈米粒子作粒徑分析、表面電荷分析與外觀型態的觀察等，進而找出形成奈米粒子的最佳條件。第二年是以Caco-2 細胞作為體外試驗模式，評估幾丁聚醣奈米粒子，對於細胞的毒性與穿透能力。並於37℃時模擬人體腸道 (pH 7.4)、胃道 (pH 1.2) 做體外釋放。第三年探討幾丁聚醣奈米粒子載負高疏水性藥物紫杉醇。探討包覆效率、藥物含量、藥物釋放及對卵巢癌細胞毒性測試。 Nanoscale drug delivery system has been developed to convey a sufficient dose of drug to lesion, provide drug targeting, increase the efficiency of drug delivery and improve release profiles. The objectives of this study is to evaluate potential of chitosan nanoparticles as carriers for the anticancer drug. This novel delivery system is prepared using a simple and mild ionic- gelation method to which a poly-γ-glutamic acid (γ-PGA) or tripolyphosphate pentasodium (TPP) solution was added to a low molecular-weight chitosan. To investigate the effect of degree of deacetylation and molecular weight of chitosan on nanoparticles characteristics prepared by ionotropic gelation and its application on the controlled release of Doxorubicin and Paclitaxel. In the first year, the investigation is to evaluate the physicochemical characteristics of these prepared nanoparticles, including the analyses of particle size, surface charges and the morphology, and then finding the optimal condition for forming nanoparticles. For the second year, we will evaluate the activity of chitosan nanoparticles by studying the effect of nanoparticles on Caco-2 in vitro cell cytotoxicity and permeability. Release study was conducted by in vitro investigation to simulate intestinal fluid and gastric fluid at 37℃. Finally, in the third year, we will to expected that drug-loaded chitosan nanoparticles for hydrophobic drugs such as the most representative drug of Paclitaxel. The drug loading content and loading efficiency, and release profile of the prepared nanoparticles and their cytotoxicity on HeLa cells were investigated in vitro

Wogonin Induces Reactive Oxygen Species Production and Cell Apoptosis in Human Glioma Cancer Cells

[[abstract]]Glioma is the most common primary adult brain tumor with poor prognosis because of the ease of spreading tumor cells to other regions of the brain. Cell apoptosis is frequently targeted for developing anti-cancer drugs. In the present study, we have assessed wogonin, a flavonoid compound isolated from Scutellaria baicalensis Georgi, induced ROS generation, endoplasmic reticulum (ER) stress and cell apoptosis. Wogonin induced cell death in two different human glioma cells, such as U251 and U87 cells but not in human primary astrocytes (IC 50 > 100 μM). Wogonin-induced apoptotic cell death in glioma cells was measured by propidine iodine (PI) analysis, Tunnel assay and Annexin V staining methods. Furthermore, wogonin also induced caspase-9 and caspase-3 activation as well as up-regulation of cleaved PARP expression. Moreover, treatment of wogonin also increased a number of signature ER stress markers glucose-regulated protein (GRP)-78, GRP-94, Calpain I, and phosphorylation of eukaryotic initiation factor-2α (eIF2α). Treatment of human glioma cells with wogonin was found to induce reactive oxygen species (ROS) generation. Wogonin induced ER stress-related protein expression and cell apoptosis was reduced by the ROS inhibitors apocynin and NAC (N-acetylcysteine). The present study provides evidence to support the fact that wogonin induces human glioma cell apoptosis mediated ROS generation, ER stress activation and cell apoptosis

Induction of osteoclast-like cell formation by leptin-induced soluble intercellular adhesion molecule secreted from cancer cells

[[abstract]]BACKGROUND: Leptin is considered a tumorigenic adipokine, suggested to promote tumorigenesis and progression in many cancers. On the other hand, intercellular adhesion molecule-1 (ICAM-1) shows altered expression in a variety of benign and malignant diseases. Histologically, ICAM-1 expression is reported as proportional to cancer stage and considered as a potential diagnosis biomarker. The altered expressions of ICAM-1 and its soluble form in malignant diseases have gained interests in recent years. MATERIAL AND METHODS: The expression of ICAM-1 and its regulatory signaling were examined by Western blot or flow cytometry. The effect of soluble ICAM-1 on osteoclast formation was investigated by tartrate-resistance acid phosphatase staining of RAW cells and tumor-induced osteolysis in vivo. RESULTS: In our study, we found that leptin enhanced soluble ICAM-1 production but not surface ICAM-1 expression in lung and breast cancer cells, and this effect was regulated through leptin receptor (ObR), while silencing ObR abrogated leptin-induced soluble ICAM-1 expression. In addition, we revealed that leptin administration provoked the JAK1/2, STAT3, FAK, ERK, and GSK3αβ signaling cascade, leading to the elevation of ICAM-1 expression. Moreover, soluble ICAM-1 secreted by leptin-stimulated cancer cells synergize with the receptor activator of nuclear factor kappa-B ligand (RANKL) in inducing osteoclast formation. Soluble ICAM also enhanced tumor-induced osteolysis in vivo. CONCLUSION: These findings suggest that soluble ICAM-1 produced under leptin treatment enhances osteoclast formation and is involved in tumor-induced osteolysis.Leptin plays an important role in physiology in health and diseases. Leptin affects immune responses that may induce inflammation and carcinogenesis. Leptin is also considered as a tumorigenic adipokine suggested to promote tumorigenesis and progression in many cancers. On the other hand, intercellular adhesion molecule-1 (ICAM-1) shows altered expression in a variety of benign and malignant diseases. Histologically, ICAM-1 expression is reported to be proportional to cancer stage and considered as a potential diagnosis biomarker. It has been reported that soluble ICAM-1 allows tumor cells to escape from immune recognition and stimulates angiogenesis and tumor growth. The altered expressions of ICAM-1 and its soluble form in malignant diseases have gained interests in recent years. In our study, we found that leptin enhanced soluble ICAM-1 production but not surface ICAM-1 expression in lung and breast cancer cells, and this effect was regulated through leptin receptor (ObR), while silencing ObR abrogated leptin-induced soluble ICAM-1 expression. In addition, we revealed that leptin administration provoked the JAK1/2, STAT3, FAK, ERK, and GSK3αβ signaling cascade, leading to the elevation of ICAM-1 expression. Moreover, soluble ICAM-1 secreted by leptin-stimulated cancer cells synergize with receptor activator of nuclear factor-kappa B ligand in inducing osteoclast formation. Soluble ICAM also enhanced tumor-induced osteolysis in vivo. These findings suggest that soluble ICAM-1 produced under leptin treatment is possibly involved in lung and breast cancer bone metastasis

Osthole Suppresses the Migratory Ability of Human Glioblastoma Multiforme Cells via Inhibition of Focal Adhesion Kinase-Mediated Matrix Metalloproteinase-13 Expression

[[abstract]]Osthole Suppresses the Migratory Ability of Human Glioblastoma Multiforme Cells via Inhibition of Focal Adhesion Kinase-Mediated Matrix Metalloproteinase-13 Expression[[abstract]]Glioblastoma multiforme (GBM) is the most common type of primary and malignant tumor occurring in the adult central nervous system. GBM often invades surrounding regions of the brain during its early stages, making successful treatment difficult. Osthole, an active constituent isolated from the dried C. monnieri fruit, has been shown to suppress tumor migration and invasion. However, the effects of osthole in human GBM are largely unknown. Focal adhesion kinase (FAK) is important for the metastasis of cancer cells. Results from this study show that osthole can not only induce cell death but also inhibit phosphorylation of FAK in human GBM cells. Results from this study show that incubating GBM cells with osthole reduces matrix metalloproteinase (MMP)-13 expression and cell motility, as assessed by cell transwell and wound healing assays. This study also provides evidence supporting the potential of osthole in reducing FAK activation, MMP-13 expression, and cell motility in human GBM cells

Growth inhibition and antioxidative status induced by selenium-enriched broccoli extract and selenocompounds in DNA mismatch repair-deficient human colon cancer cells

[[abstract]]Abstract: The effects of enzymatic-digested Se-enriched broccoli extracts (SeB) and selenocompounds on growth and antioxidative status in human colon cancer cells was investigated in this study. HCT116 and HCT116+Chr.3 cells were treated with selenocompounds (sodium selenite, sodium selenate, Se-Met, MeSeCys) or SeB [high-Se (H-SeB) or low-Se (L-SeB)]. The cytotoxicity induced by selenocompounds in HCT116 cells was not associated with cellular H2O2 level, while the differential cytotoxicity observed by sodium selenite between HCT116 and HCT116+Chr.3 cell lines was related to cellular H2O2 production with the change in antioxidative enzyme activity, and the restoration of chromosome 3. H-SeB was found to reduce the cellular H2O2 content in HCT116+Chr.3 cells. The results in this study indicate that regardless of Se content, the cytotoxicity in HCT116 cells of both SeB forms appeared to be H2O2-independent, whereas the cytotoxicity in HCT116+Chr.3 of either SeB form appeared to be H2O2-dependent with an increase in antioxidative ability for H-SeB