KOREASCHOLAR

om llnique miRNA encoding genes and also from intergene seqllences. 80 far it is generally suggestecl that one miRNA could target multiple genes. and also several miRNAs could be orchestrated to downregulate a s pecific gene. However. there would be many possibilities to procluce more miRNAs and to target gene in more compli catecl manners tha n we expected Here‘ we developed a detection program of miRNA consensus sequences from non- cocling region of genetic corcls As the ha irpin structure 01' tRNA has step-loop like hybridi zation by a single strand RNA. the repeated 3-5 nt symmetric arrangement with 6- 12 nt spanning sequences for hail‘pin head is necessary to form a preCllrsor rruRNA The DNA base pair‘ polarity program symbolizecl by the electrostatic polarities of pyrimidine and purine is now reinforcecl by the cletection program fOI symmetric DNA strand from non-coding regions. For example, we iclentifi ecl candidate miRNAs targeting eIF5A mRNA (miR-eIF5A-l)‘ 288 ribosomal RNA (miR- 28S-1). and dentin sialophosphate protein mRNA (miR- D8PP-1). 1n t his study the detection methocl of 288 ribosomal RNA was demonstrated ancl the molecular biological effects 01' miRNA targeting in vitro culture system were evaluatecl by miRNA RT• PCR, Northen blot, siRNA interference, and in situ hybridization. We firstly sea rched the candidate miRNA from the intron sequences of each objectiγe gene using the programs of syrrunetric sequence cletection a ncl DNA base pair polarity, ancl secondarily siRNA procluced by in vitro transcription and inclucible lenti virus vector cons tru ction was transfectecl into HEK293 cells. The transfectecl siRNA of miR-28S-1 was accumulated in the nucleoli ancl inclllced apoptosis extens ively in 2 days cultur8. Northern blot using miR-288-1 probe showed strong reaction in t he 288 bancJ of total RNA and also showed a smeared band in small size representing the presence of t he precursor and mature miRNAs 이 miR-288-1. In in situ hyridi zation most of cells revealed intensive miR-288-1 positive reaction in their cytopl asms. mirni cking t he abllndant localization of 288 RNA From the above study. we presume that rniRNAs targeting s pecific genes are possibly derivecl from the in tron seq uences of the objective gene, and suggest that the symmetirc sequence detect ion ancl DNA base pair polarity program is useflll to define the candiclate miRNA

• Suk Keun Lee(Department of Oral Pathology, College of Dentistry. Kangnung National University)
• Yeon Sook Kim(Department of Oral Pathology, College of Dentistry. Kangnung National University)
• Sang Shin Lee(Department of Oral Pathology, College of Dentistry. Kangnung National University)