title: Berberine induces caspase-independent cell death in colon tumor cells through activation of apoptosis-inducing factor.
abstract: Berberine, an isoquinoline alkaloid derived from plants, is a traditional medicine for treating bacterial diarrhea and intestinal parasite infections. Although berberine has recently been shown to suppress growth of several tumor cell lines, information regarding the effect of berberine on colon tumor growth is limited. Here, we investigated the mechanisms underlying the effects of berberine on regulating the fate of colon tumor cells, specifically the mouse immorto-Min colonic epithelial (IMCE) cells carrying the Apc(min) mutation, and of normal colon epithelial cells, namely young adult mouse colonic epithelium (YAMC) cells. Berberine decreased colon tumor colony formation in agar, and induced cell death and LDH release in a time- and concentration-dependent manner in IMCE cells. In contrast, YAMC cells were not sensitive to berberine-induced cell death. Berberine did not stimulate caspase activation, and PARP cleavage and berberine-induced cell death were not affected by a caspase inhibitor in IMCE cells. Rather, berberine stimulated a caspase-independent cell death mediator, apoptosis-inducing factor (AIF) release from mitochondria and nuclear translocation in a ROS production-dependent manner. Amelioration of berberine-stimulated ROS production or suppression of AIF expression blocked berberine-induced cell death and LDH release in IMCE cells. Furthermore, two targets of ROS production in cells, cathepsin B release from lysosomes and PARP activation were induced by berberine. Blockage of either of these pathways decreased berberine-induced AIF activation and cell death in IMCE cells. Thus, berberine-stimulated ROS production leads to cathepsin B release and PARP activation-dependent AIF activation, resulting in caspase-independent cell death in colon tumor cells. Notably, normal colon epithelial cells are less susceptible to berberine-induced cell death, which suggests the specific inhibitory effects of berberine on colon tumor cell growth.
authors.affiliation: Department of Pediatrics, Vanderbilt University Medical Center and the Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee, United States of America.
authors.forename: Lihong
authors.initials: L
authors.lastname: Wang
authors.forename: Liping
authors.initials: L
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.forename: Hanwei
authors.initials: H
authors.lastname: Cao
authors.forename: Rupesh
authors.initials: R
authors.lastname: Chaturvedi
authors.forename: M Wade
authors.initials: MW
authors.lastname: Calcutt
authors.forename: Tianhui
authors.initials: T
authors.lastname: Hu
authors.forename: Xiubao
authors.initials: X
authors.lastname: Ren
authors.forename: Keith T
authors.initials: KT
authors.lastname: Wilson
authors.forename: D Brent
authors.initials: DB
authors.lastname: Polk
authors.forename: Fang
authors.initials: F
authors.lastname: Yan
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000494:pharmacology*; D051033:Apoptosis Inducing Factor / Q000378:metabolism*; D001599:Berberine / Q000009:adverse effects / Q000494:pharmacology*; D020169:Caspases / Q000378:metabolism*; D002401:Cathepsin B / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003110:Colonic Neoplasms / Q000473:pathology*; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D051033:Apoptosis Inducing Factor; D017382:Reactive Oxygen Species; D001599:Berberine; D007770:L-Lactate Dehydrogenase; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases; D002401:Cathepsin B