title: Autophagy enhances the aggressiveness of human colorectal cancer cells and their ability to adapt to apoptotic stimulus.
abstract: OBJECTIVE
  To investigate LC3B-II and active caspase-3 expression in human colorectal cancer to elucidate the role of autophagy, and to explore the relationship of autophagy with apoptosis in human colorectal cancer.
  
  
  METHODS
  LC3B expression was detected by immunohistochemistry in 53 human colorectal cancer tissues and 20 normal colon tissues. The protein levels of LC3B-II and active caspase-3 were also determined by Western blot analysis in 23 human colorectal cancer tissues and 10 normal colon tissues.
  
  
  RESULTS
  LC3B was expressed both in cancer cells and normal epithelial cells. LC3B expression in the peripheral area of cancer tissues was correlated with several clinicopathological factors, including tumor differentiation (P=0.002), growth pattern of the tumor margin (P=0.028), pN (P=0.002), pStage (P=0.032), as well as vessel and nerve plexus invasion (P=0.002). The protein level of LC3B-II in cancer tissue was significantly higher than in normal tissue (P=0.038), but the expression of active forms of procaspase-3 in cancer tissue was lower (P=0.041). There was a statistically significant positive correlation between the expression levels of LC3B-II and the active forms of procaspase-3 (r=0.537, P=0.008).
  
  
  CONCLUSIONS
  Autophagy has a prosurvival role in human colorectal cancer. Autophagy enhances the aggressiveness of colorectal cancer cells and their ability to adapt to apoptotic stimulus.
authors.affiliation: Department of Pathology, The Second Hospital of Tianjin Medical University, Tianjin 300211, China.
authors.forename: Hai-Yang
authors.initials: HY
authors.lastname: Zheng
authors.forename: Xiao-Yang
authors.initials: XY
authors.lastname: Zhang
authors.forename: Xing-Fen
authors.initials: XF
authors.lastname: Wang
authors.forename: Bao-Cun
authors.initials: BC
authors.lastname: Sun
keywords: LC3B; apoptosis; autophagy; caspase-3; colorectal neoplasms