title: Expression of xCT as a predictor of disease recurrence in patients with colorectal cancer.
abstract: BACKGROUND
  The function of a cysteine-glutamate exchanger (xCT) transporter is to increase the intracellular concentration of glutathione in order to protect cells from oxidative stress. In several types of cancer, xCT is thought to play a role in the onset of resistance to chemotherapy and radiotherapy. xCT is stabilized on the tumor cell surface after combining with cluster of differentiation 44 variant (CD44v).
  
  
  METHODS
  We examined the xCT and CD44v6 expression in 304 primary tumor samples obtained from patients with colorectal cancer using immunohistochemical analysis.
  
  
  RESULTS
  Immunoreactivity for xCT was observed in 208 (68.4%) tumors. Among 218 patients with stage I-III disease who underwent curative surgery, the postoperative recurrence rate was 32.9% in those with xCT-positive tumors, which was significantly (p=0.003) higher than in those with xCT-negative tumors (10.7%). Immunoreactivity for CD44v6 was observed in 101 cases (33.2%), although the rate of postoperative recurrence in patients with CD44v6-positive tumors did not exhibit any significant correlation. Multivariate analyses revealed increased xCT expression to be an independent significant predictor of disease recurrence, in addition to depth of tumor invasion, lymph node metastasis and venous invasion.
authors: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors: Kenji
authors: K
authors: Sugano
authors: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan m1378386@med.osaka-cu.ac.jp.
authors: Kiyoshi
authors: K
authors: Maeda
authors: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors: Hiroshi
authors: H
authors: Ohtani
authors: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors: Hisashi
authors: H
authors: Nagahara
authors: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors: Masatsune
authors: M
authors: Shibutani
authors: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors: Kosei
authors: K
authors: Hirakawa
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D003545:Cysteine / Q000378:metabolism*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012307:Risk Factors
chemical_list: D014408:Biomarkers, Tumor; C112697:CD44v6 antigen; D018960:Hyaluronan Receptors; D018698:Glutamic Acid; D003545:Cysteine
keywords: CD44v6; CRC; colorectal cancer; immunohistochemistry; recurrence; xCT