title: NRSF/REST regulates the mTOR signaling pathway in oral cancer cells.
abstract: The neuron-restrictive silencer factor/repressor element 1-silencing transcription factor (NRSF/REST) was originally discovered as a transcriptional repressor of neuronal genes in non-neuronal cells. However, it was recently reported to be abundantly expressed in several types of aggressive cancer cells, as well as in mature neurons. In the present study, the role of NRSF/REST in the human oral squamous cell carcinoma (SCC) KB cell line was evaluated. NRSF/REST was expressed at a higher level in KB cells when compared with that in normal human oral keratinocytes (NHOKs). Knockdown of NRSF/REST by siRNA reduced cell viability only in KB cells in a time-dependent manner, and this effect was due to the activation of apoptosis components and DNA fragmentation. In addition, knockdown of NRSF/REST disrupted the mTOR signaling pathway which is a key survival factor in many types of cancer cells. For example, the phosphorylation of elF4G, elF4E and 4E-BP1 was significantly reduced in the KΒ cells upon NRSF/REST knockdown. These results imply that NRSF/REST plays an important role in the survival of oral cancer cells by regulating the mTOR signaling pathway.
authors.affiliation: Oral Biology Research Institute, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: Eugene
authors.initials: E
authors.lastname: Cho
authors.affiliation: Oral Biology Research Institute, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Moon
authors.affiliation: Oral Biology Research Institute, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: Bo Ram
authors.initials: BR
authors.lastname: Park
authors.affiliation: Oral Biology Research Institute, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: Do Kyung
authors.initials: DK
authors.lastname: Kim
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA.
authors.forename: Byung-Kwon
authors.initials: BK
authors.lastname: Lee
authors.affiliation: Oral Biology Research Institute, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: Chun Sung
authors.initials: CS
authors.lastname: Kim
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D017209:Apoptosis / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology*; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics; D053938:DNA Fragmentation; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D009062:Mouth Neoplasms / Q000235:genetics / Q000473:pathology*; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D034622:RNA Interference; D034741:RNA, Small Interfering; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D000099229:RE1-Silencing Transcription Factor
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D010750:Phosphoproteins; D034741:RNA, Small Interfering; D012097:Repressor Proteins; D058570:TOR Serine-Threonine Kinases; D014157:Transcription Factors; D000099229:RE1-Silencing Transcription Factor; C087000:EIF4EBP1 protein, human; C111931:ELF4 protein, human; C546842:MTOR protein, human