title: Role of Sphingolipids and Metabolizing Enzymes in Hematological Malignancies.
abstract: Sphingolipids such as ceramide, sphingosine-1-phosphate and sphingomyelin have been emerging as bioactive lipids since ceramide was reported to play a role in human leukemia HL-60 cell differentiation and death. Recently, it is well-known that ceramide acts as an inducer of cell death, that sphingomyelin works as a regulator for microdomain function of the cell membrane, and that sphingosine-1-phosphate plays a role in cell survival/proliferation. The lipids are metabolized by the specific enzymes, and each metabolite could be again returned to the original form by the reverse action of the different enzyme or after a long journey of many metabolizing/synthesizing pathways. In addition, the metabolites may serve as reciprocal bio-modulators like the rheostat between ceramide and sphingosine-1-phosphate. Therefore, the change of lipid amount in the cells, the subcellular localization and the downstream signal in a specific subcellular organelle should be clarified to understand the pathobiological significance of sphingolipids when extracellular stimulation induces a diverse of cell functions such as cell death, proliferation and migration. In this review, we focus on how sphingolipids and their metabolizing enzymes cooperatively exert their function in proliferation, migration, autophagy and death of hematopoetic cells, and discuss the way developing a novel therapeutic device through the regulation of sphingolipids for effectively inhibiting cell proliferation and inducing cell death in hematological malignancies such as leukemia, malignant lymphoma and multiple myeloma.
authors.affiliation: Tohoku Medical Megabank Organization, Sendai, Japan.|Department of Obstetrics and Gynecology, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kitatani
authors.affiliation: Medical Research Institute, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Taniguchi
authors.affiliation: Medical Research Institute, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan.|Department of Medicine, Division of Hematology/Immunology, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Okazaki
mesh_terms: D000818:Animals; D019337:Hematologic Neoplasms / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D013107:Sphingolipids / Q000235:genetics / Q000378:metabolism*
chemical_list: D013107:Sphingolipids
keywords: ceramide; leukemia; lymphoma; sphingolipid; sphingomyelin