title: Placenta-specific novel splice variants of Rho GDP dissociation inhibitor β are highly expressed in cancerous cells.
abstract: BACKGROUND
  Alternative splicing of pre-mRNA transcripts not only plays a role in normal molecular processes but is also associated with cancer development. While normal transcripts are ubiquitously expressed in normal tissues, splice variants created through abnormal alternative splicing events are often expressed in cancer cells. Although the Rho GDP dissociation inhibitor β (ARHGDIB) gene has been found to be ubiquitously expressed in normal tissues and involved in cancer development, the presence of splice variants of ARHGDIB has not yet been investigated.
  
  
  RESULTS
  Validation analysis for the presence of and exon structures of splice variants of ARHGDIB, performed using reverse-transcriptase polymerase chain reaction and DNA sequencing, successfully identified novel splice variants of ARHGDIB, that is, 6a, 6b, and 6c, in colon, pancreas, stomach, and breast cancer cell lines. Quantitative real-time polymerase chain reaction analysis showed that these variants were also highly expressed in normal placental tissue but not in other types of normal tissue.
  
  
  CONCLUSIONS
  Expression of ARHGDIB variants 6a, 6b, and 6c appears to be restricted to cancer cells and normal placental tissue, suggesting that these variants possess cancer-specific functions and, as such, are potential cancer-related biomarkers.
authors.affiliation: Medical Genetics Division, Shizuoka Cancer Center Research Institute, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka, Japan. k.hatakeyama@scchr.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hatakeyama
authors.forename: Yorikane
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ohshima
authors.forename: Masanori
authors.initials: M
authors.lastname: Terashima
authors.forename: Ken
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Tohru
authors.initials: T
authors.lastname: Mochizuki
mesh_terms: D017398:Alternative Splicing; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D005091:Exons; D005260:Female; D015870:Gene Expression; D006801:Humans; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy; D012322:RNA Precursors / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta / Q000235:genetics* / Q000378:metabolism
chemical_list: C569658:ARHGDIB protein, human; D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta