The functional characterization of long noncoding RNA SPRY4-IT1 in human melanoma cells
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.
|ISBN||1949-2553 (Electronic) 1949-2553 (Linking)|
|Authors||Mazar, J. ; Zhao, W. ; Khalil, A. M. ; Lee, B. ; Shelley, J. ; Govindarajan, S. S. ; Yamamoto, F. ; Ratnam, M. ; Aftab, M. N. ; Collins, S. ; Finck, B. N. ; Han, X. ; Mattick, J. S. ; Dinger, M. E. ; Perera, R. J.;|
|URL link to publisher's version||http://www.ncbi.nlm.nih.gov/pubmed/25344859|
|OpenAccess link to author's accepted manuscript version||https://publications.gimr.garvan.org.au/open-access/12621|