title: Cobalt chloride induces necroptosis in human colon cancer HT-29 cells.
abstract: Necroptosis, also known as "programmed necrosis", has emerged as a critical factor in a variety of pathological and physiological processes and is considered a cell type-specific tightly regulated process with mechanisms that may vary rather greatly due to the change of cell line. Here we used HT-29, a human colon cancer cell line, to establish a necroptosis model and elucidate associated mechanisms. We discovered that cobalt chloride, a reagent that could induce hypoxia-inducible factor-1α(HIF1α) expression and therefore mimic the hypoxic microenvironment of tumor tissue in some aspects induces necroptosis in HT-29 cells when caspase activity is compromised. On the other hand, apoptosis appears to be the predominant death form when caspases are functioning normally. HT-29 cells demonstrated significantly increased RIPK1, RIPK3 and MLKL expression in response to cobalt chloride plus z-VAD treatment, which was accompanied by drastically increased IL1α and IL6 expression, substantiating the notion that necrosis can induce profound immune reactions. The RIPK1 kinase inhibitor necrostatin-1 and the ROS scavenger NAC each could prevent necrosis in HT-29 cells and the efficiency was enhanced by combined treatment. Thus by building up a necroptosis model in human colon cancer cells, we uncovered that mechanically RIP kinases collaborate with ROS during necrosis promoted by cobalt chloride plus z-VAD, which leads to inflammation. Necroptosis may present a new target for therapeutic intervention in cancer cells that are resistant to apoptotic cell death.
authors.affiliation: Department of General Surgery, Zhongshan hospital, Fudan University, Shanghai, People's Republic of China E-mail : surgeonzhang@hotmail.com.
authors.forename: Hai-Yu
authors.initials: HY
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
mesh_terms: D016587:Antimutagenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D049109:Cell Proliferation; D003035:Cobalt / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008856:Microscopy, Fluorescence; D009336:Necrosis; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D016587:Antimutagenic Agents; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D003035:Cobalt; C570693:MLKL protein, human; D011494:Protein Kinases; C506249:RIPK1 protein, human; C119705:RIPK3 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; C018021:cobaltous chloride