ABSTRACT
AIM: To evaluate the growth-inhibitory effects of NS-398, a selective cyclooxygenase-2 inhibitor, in human colon cancer HT-29 cells and its possible mechanisms. METHODS: MTT assay was applied to detect the cell proliferation. Flow cytometry was performed to detect apoptosis rate and cell cycle. RT-PCR was used to detect the expression of bcl-2 mRNA and bax mRNA. Alteration of cytoskeleton component F-actin was observed by confocal laser scanning microscope. RESULTS: NS-398 could inhibit growth of HT-29 cells in dose-and time-dependent manners. Flow cytometry revealed that NS-398 could induce apoptosis and cause G0/G1 arrest of HT-29 cells in a dose-dependent manner. After 72 h incubation with NS-398 at different concentrations, the expression level of bcl-2 mRNA was lowered and the ratio of bcl-2 to bax was decreased in HT-29 cells. F-actin was mainly distributed around nuclei forming annular structure in HT-29 cells. After exposure to NS-398, the annular structure around nuclei disappeared and fluorescence intensity of F-actin decreased obviously. CONCLUSION: NS-398 can inhibit the growth effectively and induce apoptosis in HT-29 cells in vitro, which is associated with the down-regulation of bcl-2 to bax ratio and the disruption of cytoskeleton.
ABSTRACT
AIM: To study the anti-invasive effect of NS-398 on colon cancer cell line HT-29 in vitro an its regulation by CD44v6 and nm23-H1 genes. METHODS: Flow cytometry was used to detect the expression of COX-2 and CD44v6 in HT-29 cells. MTT was used for cell survival rate tests. The modified Boyden chamber model was used for quantitative invasion assay. RT-PCR was used to detect the expression of nm23-H1 mRNA. RESULTS: Flow cytometry analysis showed that COX-2 was positive in HT-29 cells. NS-398 had significant inhibitory effects on invasion of HT-29 cells, which had no relation with its cytotoxicity. NS-398 down-regulated the expression of CD44v6 and up-regulated the expression of nm23-H1 mRNA. CONCLUSION: NS-398 has an anti-invasive effect on HT-29 cells in vitro. Down-regulation of CD44v6 and up-regulation of nm23-H1 may be its underlying mechanisms.
ABSTRACT
Objective; To investigate the effect of NDGA, the lipoxygenase inhibitor, on colon cancer cell line HT-29 in vitro from the aspects of cell growth inhibition, cell apoptosis and its impact on the expression of telomerase. Methods: We applied respectively i) MTT to draw the growth curve. ii) inverted phase contrast microscope to observe morphologic change of cells, iii) scanning electron microscope to observe changes of cell's ultra-microstructure and apoptotic body. iv) RT-PCR to detect the changes of the expression of human telomerase reverse transeriptase (hTERT). Results: Different concentrations of NDGA were used to dispose cancer cells separately, with the rise of the drugis concentration, the form of cells became round, the volume waned, cells abscised from the inner surface of the bottle. and growth inhibition became increasing abvious. Also through scaming electron microscope, apoptic bodies could be found colon cancer cell line HT-29 showed positive expression of hTERTmRNA, which became weaker following the rising of the drugs concentration. Conclusions: NDGA which, displays the relying effect of doses, can inhibit the growth of colon cancer cell line HT-29 and induce its apoptosis, telomerase plays an active role in this course.
ABSTRACT
Objective:To investigate the regulatory effects of sodium butyrate on p53 target genes(p21waf1,bax,and gadd45)in HT-29 colorectal cancer cells and the related mechanisms.Methods:HT-29 cells were cultured in the absence or presence of sodium butyrate.The cell proliferation and cell cycle were studied by MTT and FCM,respectively.Apoptosis was assessed by observing cell morphology,percentage of sub-G_ 1 cells and AnnexinV-FITC.The effects of sodium butyrate on transcription of p21waf1,bax and gadd45 were analyzed by RT-PCR and Western blot.Results:Sodium butyrate inhibited proliferation and induced apoptosis of HT-29 cells in a time-and dose-dependent manner,and it blocked HT-29 cell at G_ 1 phase.Sodium butyrate stimulated p21waf1 and bax expression both at mRNA and protein level in HT-29 cells,but had little effect on the transcription of gadd45.Conclusion:Sodium butyrate can inhibit proliferation and induce apoptosis of HT-29 cells,which might be through up-regulating p21waf1 and bax expression both at mRNA and protein levels.
ABSTRACT
Objective To study the effect of imbalance of proliferation and apoptosis in the development of colorectal carcinoma(CRC),and the molecular mechanism of the dynamic change.Methods ORC was(induced) with dimethylhydrazine(DMH) in male mice of Kimming strain.The mice were killed in batches in the 12th,18th and 24th weeks of carcinoma induction.The distribution and extent of proliferation and(apoptosis) of the colorectal mucosa,at various intervals,were dynamically observed.Three genes,p21waf1,Bax and Gadd45 were analyzed by RT-PCR,immunohistochemistry and Western blot.Results During the course of carcinoma induction,the mucosas of the model mice showed sequential changes of atypital(hyperplasia),adenoma,and carcinoma.Compared with control group,the PCNA expression of the model group mice was significantly higher(P
ABSTRACT
AIM: To investigate whether cirrhosis affects the expression of hepatic glucuronosyltransferase (UGT) isoforms and its clinical significance. METHODS: Reverse transcription and polymerase chain reaction (RT-PCR) and Southern hybridization were used to determine the mRNA levels of five UGT isoforms in hepatic tissues. RESULTS: Compared to control group, UGT2B15 and UGT1A6 mRNA level in cirrhosis group increased by 227% and 166%, respectively. Compared to 0 fibrotic grade group, UGT2B15 mRNA levels of 1, 2, 4 fibrotic grade patients were 172%, 208% and 243%, respectively. UGT2B7 mRNA levels of 1, 2, 3 fibrotic grade patients were 156%, 208% and 192%, respectively. Inflammation grade showed no obvious effect on mRNA expression of most UGT isoforms. CONCLUSION: Cirrhosis affectes individual UGT isoform mRNA level. Degree of fibrosis has a significant effect on UGT mRNA expression.