title: ROS/p38/p53/Puma signaling pathway is involved in emodin-induced apoptosis of human colorectal cancer cells.
abstract: OBJECTIVE
  Emodin was found effective in suppressing proliferation of cancer cells including colorectal cancer (CRC), but the mechanisms were still unclear. This study was aimed to investigate the possible mechanism of emodin's anti-CRC effects.
  
  
  METHODS
  Two most frequently used CRC cell lines, SW480 and SW620, were investigated in this study. Serially diluted emodin solutions were used to incubate CRC cells. siRNAs were used to silence the expressions of p38 and Puma respectively. Intracellular ROS production was detected by DCFH-DA staining; proliferation and apoptosis of CRC cells were assessed by MTT assay and Hoechst staining respectively. Western blotting was applied to evaluate the activation of p38/p53/Puma signaling.
  
  
  RESULTS
  Both in SW480 and SW620 cells, emodin inhibited proliferation by inducing ROS-mediated apoptosis in a concentration-dependent manner. The p38/p53/Puma signaling was also activated after emodin incubation in a concentration-dependent manner. The ROS scavenger NAC, p38 silencing and Puma silencing impaired the anti-proliferation and apoptosis- inducing effects of emodin.
  
  
  CONCLUSIONS
  emodin inhibited proliferation of human CRC cells by inducing cell apoptosis by activating ROS/p38/p53/Puma signaling.
authors.affiliation: Second Division of Department of General Surgery, Xi'an Central Hospital Shaanxi, China.
authors.forename: Baorong
authors.initials: B
authors.lastname: Liu
authors.affiliation: Second Division of Department of General Surgery, Xi'an Central Hospital Shaanxi, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yuan
authors.affiliation: Department of General Surgery, Second Affiliated Hospital of Xi'an Jiaotong University Shaanxi, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Second Division of Department of General Surgery, Xi'an Central Hospital Shaanxi, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Mu
authors.affiliation: Second Division of Department of General Surgery, Xi'an Central Hospital Shaanxi, China.
authors.forename: Chongmin
authors.initials: C
authors.lastname: Wang
keywords: Colorectal cancer; apoptosis; emodin; reactive oxygen species