ABSTRACT
Objective: To explore the antitumor effect of oxymatrine and detect the mechanism involved. Methods: The Anti-proliferative effects of oxymatrine in human colon adenocarcinoma SW620 cells were assessed using MTT assay. SW620 cells treated with oxymatrine were assessed with Hoechst 33258 staining and cell cycle distribution assay was performed by flow cytometry. The quantitative real-time PCR assay was used to evaluate the expression of p16, cell cycle-related cyclinD1 and CDK4 mRNA at the genetic level. To investigate the molecular mechanisms underlying alterations in cell apoptosis, the proteins p16, cell cycle-related cyclinD1, and CDK4 were determined by Western blotting analysis. Results: Oxymatrine could significantly inhibit the growth of SW620 cells compared with the control group, the IC50 was 4.02 μmol/L. Its anticancer activity was related to the alteration in expression of p16, cyclinD1, and CDK4 (P<0.05, 0.01). Conclusion: These results suggest that oxymatrine produces the obvious antitumor effects on SW620 cells in vitro, induces the cell arrest in G1 phase which is related to the regulation on the protein expression of p16, cyclinD1, and CDK4.
ABSTRACT
Objective: To investigate the effects of phospholipase C epsilon-1 (PLCE1 ) over-expression on migration, cell cycle and apoptosis of human colon cancer cells. Methods: The SW620 cells overexpressing PLCE1 were constructed through lipofection. Three groups were designed as follows: parent group (without transfection), control group (transfected with empty plasmid containing green fluorescent protein) and experimental group (transfected with pcDNA-DEST53-PLCE1 plasmid). The expression levels of PLCE1 mRNA and protein in SW620 cells were detected by real-time fluorogenic quantitative-PCR (RFQ-PCR) and Western blotting, respectively. The effect of PLCE 1 over-expression on migation ability of SW620 cells was detected by Transwell chamber assay. The cell cycle distribution and apoptosis rate of SW620 cells were detected by flow cytometry (FCM). The apoptosis was analyzed by using DNA ladder method. Results: The migration ability of SW620 colon cancer cells was inhibited by over-expression of PLCE 1. The numbers of migrated cells in the parent, control and experimental groups were 32.60±2.42, 32.20±3.25 and 8.80±1.72, respectively, and the difference among three groups was significant (P < 0.01). The over-expression of PLCE1 prolonged phase G1 and induced apoptosis. Conclusion: PLCE1 over-expression can inhibit the migration ability of colon cancer cells and induce their apoptosis. PLCE1 over-expression can reduce the malignant degree of colon cancer cells, and this gene may be a new antioncogene related to colon cancer. Copyright© 2011 by TUMOR.
ABSTRACT
Objective To inhibit the expression of transcription factor special protein 1(Sp1) through RNA interference (RNAi) technique and to investigate its impact on the proliferation ability of colorectal cancer cell line SW620. Methods The recombinant plasmid of Sp1 RNAi (pGenesil-1-Sp1) was constructed and transfected into SW620 cells by Lipofectamine. The transfcction efficiency was observed under fluorescence confocal microscopy. Expression levels of Sp1 mRNA and protein from SW620 after transfection were examined by real time PCR and Western blot respectively, after transduction of the recombinant plasmid into the SW620. The proliferation ability of SW620 cell line was evaluated by MTT assay. Results The expression plasmid (pGenesil-1-Sp1) against Sp1 was successfully constructed, recombinant vectors could reduce the expressions of Sp1 mRNA and protein in SW620, the ratio of inhibition of the expression of Sp1 mRNA and protein was 68.47 % and 73.82 % in 48th hour respectively. Compared with the control group, the difference was significant (P <0.05). MTT showed that the proliferation ability of SW620 cell was degraded. Conclusion Silencing Sp1 gene by the RNAi technology can actively inhibit the proliferation of SW620 cell. The successful application of Spl SiRNA extends the list of available therapeutic modalitics in the treatment of human colon cancer.