title: The functional characterization of long noncoding RNA SPRY4-IT1 in human melanoma cells.
abstract: Expression of the long noncoding RNA (lncRNA) SPRY4-IT1 is low in normal human melanocytes but high in melanoma cells. siRNA knockdown of SPRY4-IT1 blocks melanoma cell invasion and proliferation, and increases apoptosis. To investigate its function further, we affinity purified SPRY4-IT1 from melanoma cells and used mass spectrometry to identify the protein lipin 2, an enzyme that converts phosphatidate to diacylglycerol (DAG), as a major binding partner. SPRY4-IT1 knockdown increases the accumulation of lipin2 protein and upregulate the expression of diacylglycerol O-acyltransferase 2 (DGAT2) an enzyme involved in the conversion of DAG to triacylglycerol (TAG). When SPRY4-IT1 knockdown and control melanoma cells were subjected to shotgun lipidomics, an MS-based assay that permits the quantification of changes in the cellular lipid profile, we found that SPRY4-IT1 knockdown induced significant changes in a number of lipid species, including increased acyl carnitine, fatty acyl chains, and triacylglycerol (TAG). Together, these results suggest the possibility that SPRY4-IT1 knockdown may induce apoptosis via lipin 2-mediated alterations in lipid metabolism leading to cellular lipotoxicity.
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Mazar
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
authors.forename: Ahmad M
authors.initials: AM
authors.lastname: Khalil
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Bongyong
authors.initials: B
authors.lastname: Lee
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: John
authors.initials: J
authors.lastname: Shelley
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Subramaniam S
authors.initials: SS
authors.lastname: Govindarajan
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Yamamoto
authors.affiliation: Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
authors.forename: Maya
authors.initials: M
authors.lastname: Ratnam
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Muhammad Nauman
authors.initials: MN
authors.lastname: Aftab
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Sheila
authors.initials: S
authors.lastname: Collins
authors.affiliation: Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Brian N
authors.initials: BN
authors.lastname: Finck
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Xianlin
authors.initials: X
authors.lastname: Han
authors.affiliation: Garvan Institute of Medical Research and St Vincent's Clinical School, University of New South Wales, Darlinghurst NSW 2010, Australia.
authors.forename: John S
authors.initials: JS
authors.lastname: Mattick
authors.affiliation: Garvan Institute of Medical Research and St Vincent's Clinical School, University of New South Wales, Darlinghurst NSW 2010, Australia.
authors.forename: Marcel E
authors.initials: ME
authors.lastname: Dinger
authors.affiliation: Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors.forename: Ranjan J
authors.initials: RJ
authors.lastname: Perera
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D002331:Carnitine / Q000096:biosynthesis; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics; D051048:Diacylglycerol O-Acyltransferase / Q000096:biosynthesis; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D050356:Lipid Metabolism / Q000235:genetics; D008545:Melanoma / Q000235:genetics*; D009361:Neoplasm Invasiveness / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009687:Nuclear Proteins / Q000378:metabolism*; D034622:RNA Interference; D062085:RNA, Long Noncoding / Q000096:biosynthesis / Q000235:genetics*; D034741:RNA, Small Interfering; D014280:Triglycerides / Q000096:biosynthesis
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C502575:LPIN2 protein, human; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D062085:RNA, Long Noncoding; D034741:RNA, Small Interfering; C499038:SPRY4 protein, human; D014280:Triglycerides; C494885:DGAT2 protein, human; D051048:Diacylglycerol O-Acyltransferase; D002331:Carnitine