Esophageal Cancer Eca109 Cells Research Articles

Effect of DNA methyltransferase 5-aza-2'-deoxycytidine on proliferation of human esophageal squamous cancer cell line Eca109 in vitro

Objective To explore the effect of the DNA methyltransferase 5-aza-2'-deoxycytidine (5-aza-CdR)on human esophageal squamous cancer Ecal09 cells.nethods Human esophageal squamous cell cancer(ESCC)Eca109 cells were treated by 5-aza-CdR with 10-7,10-6,1O-5,10-4,0 mol/L. Respectively.Consequently,the growth rate of the cells was detected by MTT assay and morphological structure Was observed.Meanwhile,cell apoptosis and cell cycle were analyzed by flow cytometry method. (FCM).ResulIs The proliferation of Eea109 cells Was inhibited by 5-aza-CdR from 10-7 to 10-4 mol/L Moreover,the inhibition rate showed time-and-concentration-dependent manner(24～96 h,F=160.06,P=0.000,10-7～10-4 mol/L,F:60.95,P:0.000).The maximum rate of inhibitory was reached up to(15.70±0.75)% in the group treated by 10-4 mol/L 5-aza-CdR after 96 hours.An apoptosis peak appeared before diploid peak.The proportion of Go/G1 phase cells Was significantly increased(F=6479.46, P=0.000),especially up to(89.70±0.91)% in the group treated by 10-4 mo/L 5-aza-CdR after 96 h. However,the proportion of S phase cells Was obviously decreased(F=4222.26,P=0.000),especially down to(9.10±0.48)% in the group treated bv 10-4mol/L 5-aza-CdR after 96 h.Conclusions The proliferation of Eca109 cells is inhibited bv 5-aza-CdR in a time-and-concentration-dependent manner.Moreover,the 5-aza-CdR can inhibit cell growth by regulation of DNA cycle and apoptosis. Key words: Esophageal neoplasms; Tumor cells,caltured; Azacitidine DNA methylation

Bile salts inhibit growth and induce apoptosis of human esophageal cancer cell line.

To explore the effect of six bile salts, including glycocholate (GC), glycochenodeoxycholate (GCDC), glycodeoxycholate (GDC), taurocholate (TC), taurochenodeoxycholate (TCDC), taurodeoxycholate (TDC), and two bile acids including cholic acid (CA) and deoxycholic acid (DCA) on esophageal cancer Eca109 cell line. Eca109 cells were exposed to six bile salts, two bile acids and the mixed bile salts at different concentrations for 24-72 h. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to detect the cell proliferation. Apoptotic morphology was observed by phase-contrast video microscopy and deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Sub-G1 DNA fragmentations and early apoptosis cells were assayed by flow cytometry (FCM) with propidium iodide (PI) staining and annexin V-FITC conjugated with PI staining. Apoptosis DNA ladders on agarose were observed. Activation of caspase-3 was assayed by FCM with FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody and expressions of Bcl-2 and Bax proteins were examined immunocytochemically in 500 micromol/L-TC-induced apoptosis cells. Five bile salts except for GC, and two bile acids and the mixed bile salts could initiate growth inhibition of Eca109 cells in a dose- and time-dependent manner. TUNEL, FCM, and DNA ladder assays all demonstrated apoptosis induced by bile salts and bile acids at 500 micromol/L, except for GC. Early apoptosis cell percentages in Eca109 cells treated with GCDC, GDC, TC, TCDC, TDC, CA at 500 micromol/L for 12 h, DCA at 500 micromol/L for 6 h, and mixed bile salts at 1000 micromol/L for 12 h were 7.5%, 8.7%, 14.8%, 8.9%, 7.8%, 9.3%, 22.6% and 12.5%, respectively, all were significantly higher than that in control (1.9%). About 22% of the cell population treated with TC at 500 micromol/L for 24 h had detectable active caspase-3, and were higher than that in the control (1%). Immunocytochemical assay suggested that TC down-regulated Bcl-2 protein level and up-regulated Bax protein level. GCDC, GDC, TC, TCDC, TDC, CA and DCA, except for GC, can inhibit growth and induce apoptosis of esophageal cancer Eca109 cells. Activation of caspase-3, decreased Bcl-2 protein and increased Bax protein are involved in TC-induced apoptosis of Eca109 cells.