AIM: To investigate biogenesis and intracellular Iocalizations of clusterin to elucidate the potential molecular mechanisms implicated in tumorigenesis of esophageal mucosa.METHODS: Semi-quantitative RT-PCR for multi-...AIM: To investigate biogenesis and intracellular Iocalizations of clusterin to elucidate the potential molecular mechanisms implicated in tumorigenesis of esophageal mucosa.METHODS: Semi-quantitative RT-PCR for multi-region alteration analysis, Western blot for different transcriptional forms and immunohistochemical staining for intracellular Iocalizations of clusterin were carried out in both tissues and cell lines of ESCC.RESULTS: The N-terminal deletions of the clusterin gene and the appearance of a 50-53 ku nuclear clusterin, an uncleaved, nonglycosylated, and disulfide-linked isoform,were the major alterations in cancer cells of esophagus.Naturally the 40 ku clusterin was located in the connective tissue of the lamina propria of epithelial mucosa and right under the basal membrane of epithelia, but it was disappeared in stromal mucosa of esophagus and the pre-matured clusterin was found positive in cancerous epithelia.CONCLUSION: The N-terminal deletion of clusterin may be essential for its alterations of biogenesis in ESCC.展开更多
AIM: To study the effect of NS-398, a selective cydooxygenase 2 (COX-2) inhibitor, on invasion of colon cancer cell line HT-29 in vitro and to explore its mechanisms. METHODS: Invasive behaviors of the malignant colon...AIM: To study the effect of NS-398, a selective cydooxygenase 2 (COX-2) inhibitor, on invasion of colon cancer cell line HT-29 in vitro and to explore its mechanisms. METHODS: Invasive behaviors of the malignant colon cancer cell line HT-29 were investigated in this study. Expressions of COX-2 and CD44v6 in HT-29 cells were detected by flow cytometry. Cellular survival rate was determined by MTT assay. The invasive capacity was quantified by a modified Boyden chamber model. Alterations of cytoskeleton component F-actin were observed by confocal laser scanning microscope. RESULTS: Flow cytometry analysis showed that COX-2 was highly expressed in HT-29 cells. The invasive capability of HT-29 cells could be greatly inhibited by NS-398 at the experimental concentrations of 0.1,1.0 and 10 μmol/L with an inhibitory rate of 22.74%, 42.35% and 58.61% (P<0.01), respectively. MTT assay showed that NS-398 at the experimental concentrations had no significant influence on cellular viability, indicating that such anti-invasive effects had no relationship with cytotoxicity. F-actin was mainly distributed around nuclei forming annular structure in HT-29 cells. After exposure to NS-398 of 10 μmol/L, the annular structure around nuclei disappeared and the fluorescence intensity of F-actin decreased obviously. Treatment with NS-398 could down-regulate the expression of CD44v6 as well. CONCLUSION: NS-398 has anti-invasive effects on colon cancer HT-29 cells in vitro, which may be mediated by a novel mechanism of disruption of cytoskeleton. Down-regulation of CD44v6 expression may be related to alterations of cytoskeleton.展开更多
基金Supported by National Natural Science Foundation,No.30225045,No.39990570,No.30171049 and No.30370713,and National High Tech and Major State Basic R & D Program of China,No.G 1998051205and No.2001AA227091
文摘AIM: To investigate biogenesis and intracellular Iocalizations of clusterin to elucidate the potential molecular mechanisms implicated in tumorigenesis of esophageal mucosa.METHODS: Semi-quantitative RT-PCR for multi-region alteration analysis, Western blot for different transcriptional forms and immunohistochemical staining for intracellular Iocalizations of clusterin were carried out in both tissues and cell lines of ESCC.RESULTS: The N-terminal deletions of the clusterin gene and the appearance of a 50-53 ku nuclear clusterin, an uncleaved, nonglycosylated, and disulfide-linked isoform,were the major alterations in cancer cells of esophagus.Naturally the 40 ku clusterin was located in the connective tissue of the lamina propria of epithelial mucosa and right under the basal membrane of epithelia, but it was disappeared in stromal mucosa of esophagus and the pre-matured clusterin was found positive in cancerous epithelia.CONCLUSION: The N-terminal deletion of clusterin may be essential for its alterations of biogenesis in ESCC.
文摘AIM: To study the effect of NS-398, a selective cydooxygenase 2 (COX-2) inhibitor, on invasion of colon cancer cell line HT-29 in vitro and to explore its mechanisms. METHODS: Invasive behaviors of the malignant colon cancer cell line HT-29 were investigated in this study. Expressions of COX-2 and CD44v6 in HT-29 cells were detected by flow cytometry. Cellular survival rate was determined by MTT assay. The invasive capacity was quantified by a modified Boyden chamber model. Alterations of cytoskeleton component F-actin were observed by confocal laser scanning microscope. RESULTS: Flow cytometry analysis showed that COX-2 was highly expressed in HT-29 cells. The invasive capability of HT-29 cells could be greatly inhibited by NS-398 at the experimental concentrations of 0.1,1.0 and 10 μmol/L with an inhibitory rate of 22.74%, 42.35% and 58.61% (P<0.01), respectively. MTT assay showed that NS-398 at the experimental concentrations had no significant influence on cellular viability, indicating that such anti-invasive effects had no relationship with cytotoxicity. F-actin was mainly distributed around nuclei forming annular structure in HT-29 cells. After exposure to NS-398 of 10 μmol/L, the annular structure around nuclei disappeared and the fluorescence intensity of F-actin decreased obviously. Treatment with NS-398 could down-regulate the expression of CD44v6 as well. CONCLUSION: NS-398 has anti-invasive effects on colon cancer HT-29 cells in vitro, which may be mediated by a novel mechanism of disruption of cytoskeleton. Down-regulation of CD44v6 expression may be related to alterations of cytoskeleton.
