title: Clinical significance of human kallikrein gene 6 messenger RNA expression in colorectal cancer.
abstract: OBJECTIVE
  Human kallikrein gene 6 (KLK6) is a member of the human kallikrein gene family, and recent studies have found that many kallikreins have altered expression patterns in various malignancies. The purpose of the current study was to quantify the expression of KLK6 in malignant and benign colorectal tissues and to statistically analyze whether KLK6 expression levels correlate with clinicopathologic variables and prognosis in patients with colorectal cancer.
  
  
  METHODS
  Paired colorectal tissue samples from cancerous and corresponding noncancerous tissues were obtained from 63 patients with colorectal cancer who underwent surgical resection. Quantitative analyses of KLK6 mRNA expression were done using real-time quantitative reverse transcription-PCR.
  
  
  RESULTS
  KLK6 mRNA overexpression in cancerous tissues compared with normal counterparts was observed in 57 of 63 (90%) patients. The mean expression level of KLK6 mRNA in cancerous tissues was significantly higher than that in noncancerous tissues (P < 0.0001). Elevated KLK6 expression was significantly correlated with serosal invasion (P < 0.05), liver metastasis (P < 0.05), and advanced Duke's stage (P < 0.01). Furthermore, patients with high KLK6 expression had a significantly poorer actuarial overall survival than patients with low KLK6 expression (5-year overall survival rates: 54% and 73%, respectively, P < 0.05).
  
  
  CONCLUSIONS
  The results of this study indicated that KLK6 mRNA expression was significantly higher in cancerous than in noncancerous colorectal tissues, and high expression of KLK6 mRNA correlated with serosal invasion, liver metastasis, advanced Duke's stage, and a poor prognosis for patients with colorectal cancer.
authors.affiliation: Department of Molecular and Surgical Oncology, Medical Institute of Bioregulation, Kyushu University, Beppu, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ogawa
authors.forename: Tohru
authors.initials: T
authors.lastname: Utsunomiya
authors.forename: Koshi
authors.initials: K
authors.lastname: Mimori
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Tanaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inoue
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nagahara
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Murayama
authors.forename: Masaki
authors.initials: M
authors.lastname: Mori
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000235:genetics / Q000473:pathology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007610:Kallikreins / Q000235:genetics*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis
chemical_list: D012333:RNA, Messenger; C103551:KLK6 protein, human; D007610:Kallikreins