title: [Biological significance of relationship between nuclear localization of Rac1 and progression of gastric carcinoma].
abstract: OBJECTIVE
  To observe the subcellular localization of Rac1 and the expression of Tiam1 and Rac1 in gastric carcinoma, in order to reveal the relationship between the distribution of Rac1 and progression of gastric carcinoma.
  
  
  METHODS
  Both carcinoma and adjacent normal tissue of 48 patients with gastric carcinoma were studied in this study. Tissue distribution and expression of Rac1 and Tiam1 were analyzed by immunohistochemistry and real-time polymerase chain reaction (PCR).
  
  
  RESULTS
  Compared with that of adjacent non-cancerous gastric mucosa, the expression of Rac1 in cancer tissues was significantly increased. The positive rate of Rac1 expression was 18.8% (9/48 cases) in adjacent non-neoplastic gastric and 79.2% (38/48 cases) in cancer tissues. The positive staining was mainly located in the cell nuclei (31 samples). The real-time PCR results demonstrated that the expression levels of Tiam1 and Rac1 mRNA in cancerous tissues with nuclear localization of Rac1 were evidently increased. Furthermore, nuclear localization of Rac1 was associated with tumor stage and metastasis.
  
  
  CONCLUSIONS
  The majority of gastric cancer tissues show nuclear dislocalization of Rac1 expression, which may be a sign of abnormal activation of Tiam1-Rac1 pathway. It may suggest enhanced invasion ability of the gastric carcinoma.
authors.affiliation: Department of Laboratory Medicine, Jilin University, Changchun, China.
authors.forename: Long
authors.initials: L
authors.lastname: Su
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Guang-zhi
authors.initials: GZ
authors.lastname: Yan
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Ying-li
authors.initials: YL
authors.lastname: Wang
authors.forename: Shuang
authors.initials: S
authors.lastname: Chen
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Li-hua
authors.initials: LH
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002467:Cell Nucleus / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology*; D000075684:T-Lymphoma Invasion and Metastasis-inducing Protein 1; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D020662:Guanine Nucleotide Exchange Factors; D012333:RNA, Messenger; D000075684:T-Lymphoma Invasion and Metastasis-inducing Protein 1; C087334:TIAM1 protein, human; D020830:rac1 GTP-Binding Protein