title: Polyunsaturated fatty acids trigger apoptosis of colon cancer cells through a mitochondrial pathway.
abstract: BACKGROUND
  Colorectal cancer is common in developed countries. Polyunsaturated fatty acids (PUFAs) have been reported to possess tumoricidal action, but the exact mechanism of their action is not clear.
  
  
  METHODS
  In the present study, we studied the effect of various n-6 and n-3 fatty acids on the survival of the colon cancer cells LoVo and RKO and evaluated the possible involvement of a mitochondrial pathway in their ability to induce apoptosis.
  
  
  RESULTS
  It was observed that n-3 α-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid (ALA, EPA and DHA respectively) and n-6 linoleic acid, gamma-linolenic acid and arachidonic acid (LA, GLA and AA respectively) induced apoptosis of the colon cancer cells LoVo and RKO at concentrations above 120 μM (p < 0.01 compared to control). The semi-differentiated colon cancer cell line RKO was more sensitive to the cytotoxic action of PUFAs compared to the undifferentiated colon cancer cell line LoVo. PUFA-treated cells showed an increased number of lipid droplets in their cytoplasm. PUFA-induced apoptosis of LoVo and RKO cells is mediated through a mitochondria-mediated pathway as evidenced by loss of mitochondrial membrane potential, generation of ROS, accumulation of intracellular Ca(2+), activation of caspase-9 and caspase-3, decreased ATP level and increase in the Bax/Bcl2 expression ratio.
  
  
  CONCLUSIONS
  PUFAs induced apoptosis of colon cancer cells through a mitochondrial dependent pathway.
authors.affiliation: Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.
authors.forename: Chengcheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China.
authors.forename: Haining
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.
authors.forename: Yuzhen
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Ni
authors.affiliation: Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.
authors.forename: Shengrong
authors.initials: S
authors.lastname: Shen
authors.affiliation: UND Life Sciences, USA ; Bioscience Research Centre, GVP College of Engineering Campus, Visakhapatnam, India.
authors.forename: Undurti N
authors.initials: UN
authors.lastname: Das
keywords: ATP; apoptosis; caspases; colon cancer; lipid droplets; mitochondrial pathway; polyunsaturated fatty acids