title: [A pivotal role of cortactin, a CTTN encoding protein, in endocytosis of human colon cancer].
abstract: OBJECTIVE
  To explore the role of cortactin in endocytosis of colon cancer cells and clarify the significance of its over-expression in colon cancer tissues.
  
  
  METHODS
  Immunohistochemistry and Western blot were employed to detect the expression of cortactin in benign and malignant tissues and cells. Cell endocytosis was examined in cancer cells after siRNA treatment and DNA transfection with plasmid encoding cortactin wild type and domain deletion mutants.
  
  
  RESULTS
  Cortactin was over-expressed in colon cancer tissues than in adjacent normal tissues. The expression rate was 77.5% in cancer tissues and 47.5% in normal tissues (P < 0.05). The value of transferrin uptake was 0.61 ± 0.02 in siRNA treated cancer cells and 1.01 ± 0.16 in the control cells (P < 0.05). Intact molecule and sufficient level of cortactin was required for an optimal endocytosis of cancer cells. Cortactin was involved in coated-vesicle transportation in cells.
  
  
  CONCLUSIONS
  Endocytosis in colon cancer cells is dependent on an intact expression of CTTN. An over-expression of cortactin facilitates the signaling in invasion and metastasis related to endocytosis.
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital, Nantong University, Nantong 226001, China. Email: usazhujianwei@yahoo.com.cn
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Zhu
authors.forename: Li-Lin
authors.initials: LL
authors.lastname: Ma
authors.forename: Bao-Yu
authors.initials: BY
authors.lastname: Huang
authors.forename: Pei-Geng
authors.initials: PG
authors.lastname: Liu
authors.forename: Kai
authors.initials: K
authors.lastname: Ru
authors.forename: Xiang
authors.initials: X
authors.lastname: Cao
authors.forename: Fei
authors.initials: F
authors.lastname: Qian
mesh_terms: D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism*; D051356:Cortactin / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis; D006801:Humans
chemical_list: C495868:CTTN protein, human; D051356:Cortactin