Objective:To investigate whether eytochalasin D can induce antitumor activities in a tumor model.Methods:Murine CT26 colorectal carcinoma cells were cultured hi vitro and cytochalasin D was used as a cytotoxic agent t...Objective:To investigate whether eytochalasin D can induce antitumor activities in a tumor model.Methods:Murine CT26 colorectal carcinoma cells were cultured hi vitro and cytochalasin D was used as a cytotoxic agent to detect its capabilities of inhibiting CT26 cell proliferation and inducing cell apoptosis by MTT and a TUNEL-based apoptosis assay.Murine CT26 tumor model was established to observe the tumor growth and survival time.Tumor tissues were used to detect the mierovessel density by immunohistochemistry.In addition,alginate encapsulated tumor cell assay was used to quantify the tumor angiogenesis in vivo.Results:Cytochalasin D inhibited CT26 tumor cell proliferation in lime and dose dependent manner and induced signiflcanl CT26 cell apoptosis,which almost reached the level induced by the positive control nuclease.The optimum effective dose of cytochalasin D for in vivo therapy was about 50 mg/kg.Cytochalasin D in vivo treatment significandy inhibited tumor growth and prolonged the survival times in CT26 tumor-bearing mice.The results of immunohistochemistry analysis and alginate encapsulation assay indicated that the cytochalasin D could effectively inhibited tumor angiogenesis. Conclusions:Cytochalasin D inhibits CT26 tumor growth potentially through inhibition of cell proliferation,induction of cell apoptosis and suppression of tumor angiogenesis.展开更多
Actin filaments (AFs) in un-fixed pollen tubes of Amaryllis vittata Ait were visualized after TRITC-phalloidin staining with DMSO as a permeabilising agent. Typically, strands or hundles of microfilaments (Mfs) were d...Actin filaments (AFs) in un-fixed pollen tubes of Amaryllis vittata Ait were visualized after TRITC-phalloidin staining with DMSO as a permeabilising agent. Typically, strands or hundles of microfilaments (Mfs) were distributed in the extreme tip as well as pollen tubes in a form of network.Fluorescent granules or circles of various sizes were frequently found that continued with the filamentous structures. In addition, a more brightly stained structure, possibly Mf organizing center, was observed. Treatment of pollen tubes with cytochalasin D(CD)for increasing time intervals (5-40 minutes) caused gradual reduction of strands until flurescent granules filled up the pollen tubes. Mcanwhile, cytoplasmie streaming was inhibited completely. Though closely associated with vegetative nuclei (VN) and generative cells (GC), AFs were not found in the cytoplasm of GC.Mg++concentration greatly affected the isolated Mfs.展开更多
The adhesion properties of both hepatocytes and hepatocellular carcinoma cells (HCCs) onto the Coll IV/laminin coated surface were measured by means of micropipette aspiration technique. Further,relevances of microfil...The adhesion properties of both hepatocytes and hepatocellular carcinoma cells (HCCs) onto the Coll IV/laminin coated surface were measured by means of micropipette aspiration technique. Further,relevances of microfilament and microtubule systems to the adhesion properties of the HCCs on Coll IV/laminin coated dishes were investigated by using cytoskeletal agents colchicine and cytochalasin D. The results showed: cytochalasin D, which inhibits microfilament polymerization, had great inhibitory effect on adherence of both kinds of cells to Coll IV/ Laminin substratum (about 70%～90%). At the same time, HCCs extension obviously decreased and focal contacts almost vanished after being treated with cytochalasin D, in contrast, there was no significant effect on the formation of extention of hepatocytes. Colchicine, which inhibits microtubular polymerization, had different effects on both cells: Compared with untreated groups, the adhesion forces of HCC cells decreased and those of hepatocytes increased. These data suggested that, in these tumor cells, microfilament system are crucial for adherence, and abnormal cytoskeletons of tumor cells may be basis of their abnormal adhesion properties.展开更多
The interphase nuclei of parenchyma cells and epidermal cells of garlic ( Allium sativum L.) clove were labelled with rabbit anti_actin antibody and FITC_conjugated goat anti_rabbit IgG antibody. The authors observ...The interphase nuclei of parenchyma cells and epidermal cells of garlic ( Allium sativum L.) clove were labelled with rabbit anti_actin antibody and FITC_conjugated goat anti_rabbit IgG antibody. The authors observed results with fluorescence microscopy and confocal laser scanning microscopy. The nuclei showed prominent green_yellow fluorescence, indicating the presence of actin in the nuclei. Fluorescence examination with TRITC_phalloidin showed distinctive red fluorescence in the nuclei, indicating that F_actin is present in the nuclei. Confocal laser scanning microscopy indicated the presence of F_actin containing network structures in the nuclei, but the network structures were absent and the nuclei still showed red fluorescence when the cells were treated with cytochalasin D before fixation; the red fluorescence in the nuclei was hard to be observed when the cells were treated with unlabelled phalloidin before the cells were stained with TRITC_phalloidin. These results indicate that F_actin is in the nuclei and forms network structures in the nuclei of garlic cells.展开更多
基金partially funded by National Basie Research Program of China(2010CB534909)National Natural Seience Foundation of China (30960411 and 81160288)Hainan Provincial Key Scientific Project(061009)
文摘Objective:To investigate whether eytochalasin D can induce antitumor activities in a tumor model.Methods:Murine CT26 colorectal carcinoma cells were cultured hi vitro and cytochalasin D was used as a cytotoxic agent to detect its capabilities of inhibiting CT26 cell proliferation and inducing cell apoptosis by MTT and a TUNEL-based apoptosis assay.Murine CT26 tumor model was established to observe the tumor growth and survival time.Tumor tissues were used to detect the mierovessel density by immunohistochemistry.In addition,alginate encapsulated tumor cell assay was used to quantify the tumor angiogenesis in vivo.Results:Cytochalasin D inhibited CT26 tumor cell proliferation in lime and dose dependent manner and induced signiflcanl CT26 cell apoptosis,which almost reached the level induced by the positive control nuclease.The optimum effective dose of cytochalasin D for in vivo therapy was about 50 mg/kg.Cytochalasin D in vivo treatment significandy inhibited tumor growth and prolonged the survival times in CT26 tumor-bearing mice.The results of immunohistochemistry analysis and alginate encapsulation assay indicated that the cytochalasin D could effectively inhibited tumor angiogenesis. Conclusions:Cytochalasin D inhibits CT26 tumor growth potentially through inhibition of cell proliferation,induction of cell apoptosis and suppression of tumor angiogenesis.
文摘Actin filaments (AFs) in un-fixed pollen tubes of Amaryllis vittata Ait were visualized after TRITC-phalloidin staining with DMSO as a permeabilising agent. Typically, strands or hundles of microfilaments (Mfs) were distributed in the extreme tip as well as pollen tubes in a form of network.Fluorescent granules or circles of various sizes were frequently found that continued with the filamentous structures. In addition, a more brightly stained structure, possibly Mf organizing center, was observed. Treatment of pollen tubes with cytochalasin D(CD)for increasing time intervals (5-40 minutes) caused gradual reduction of strands until flurescent granules filled up the pollen tubes. Mcanwhile, cytoplasmie streaming was inhibited completely. Though closely associated with vegetative nuclei (VN) and generative cells (GC), AFs were not found in the cytoplasm of GC.Mg++concentration greatly affected the isolated Mfs.
基金Supported by the NNSF of China(No.3 950 0 0 3 7)
文摘The adhesion properties of both hepatocytes and hepatocellular carcinoma cells (HCCs) onto the Coll IV/laminin coated surface were measured by means of micropipette aspiration technique. Further,relevances of microfilament and microtubule systems to the adhesion properties of the HCCs on Coll IV/laminin coated dishes were investigated by using cytoskeletal agents colchicine and cytochalasin D. The results showed: cytochalasin D, which inhibits microfilament polymerization, had great inhibitory effect on adherence of both kinds of cells to Coll IV/ Laminin substratum (about 70%～90%). At the same time, HCCs extension obviously decreased and focal contacts almost vanished after being treated with cytochalasin D, in contrast, there was no significant effect on the formation of extention of hepatocytes. Colchicine, which inhibits microtubular polymerization, had different effects on both cells: Compared with untreated groups, the adhesion forces of HCC cells decreased and those of hepatocytes increased. These data suggested that, in these tumor cells, microfilament system are crucial for adherence, and abnormal cytoskeletons of tumor cells may be basis of their abnormal adhesion properties.
文摘The interphase nuclei of parenchyma cells and epidermal cells of garlic ( Allium sativum L.) clove were labelled with rabbit anti_actin antibody and FITC_conjugated goat anti_rabbit IgG antibody. The authors observed results with fluorescence microscopy and confocal laser scanning microscopy. The nuclei showed prominent green_yellow fluorescence, indicating the presence of actin in the nuclei. Fluorescence examination with TRITC_phalloidin showed distinctive red fluorescence in the nuclei, indicating that F_actin is present in the nuclei. Confocal laser scanning microscopy indicated the presence of F_actin containing network structures in the nuclei, but the network structures were absent and the nuclei still showed red fluorescence when the cells were treated with cytochalasin D before fixation; the red fluorescence in the nuclei was hard to be observed when the cells were treated with unlabelled phalloidin before the cells were stained with TRITC_phalloidin. These results indicate that F_actin is in the nuclei and forms network structures in the nuclei of garlic cells.
