title: Increased expression of myosin light chain kinase mRNA is related to metastasis in non-small cell lung cancer.
abstract: BACKGROUND
  The invasiveness of tumor cells depends in large part on their motility, which in turn depends on cytoskeletal function. A major cytoskeletal component involved in cell motility is myosin II, the classical form of myosin first identified in muscle but also expressed in nonmuscle cells. Myosin II is activated by myosin light chain kinase (MLCK), which phosphorylates it on its regulatory light chain. In this context, the contribution made by MLCK to tumor cell motility and invasiveness has been investigated extensively in vitro, but clinical evidence of such a contribution has been lacking. In the present study, therefore, we examined the role of MLCK in the metastasis of non-small cell lung cancer (NSCLC) in a clinical setting.
  
  
  METHODS
  We measured MLCK mRNA expression in tumor samples from 39 NSCLC patients using real-time semiquantitative reverse transcription polymerase chain reaction carried out in a LightCycler. We then correlated MLCK mRNA expression with known clinicopathological factors.
  
  
  RESULTS
  We found that levels of MLCK mRNA expression were higher in patients who showed disease recurrence and distant metastasis than in those who did not. Moreover, the 3-year disease-free survival rate among patients showing lower levels of MLCK mRNA expression [log10(MLCK/GAPDH) <1.4] was significantly greater than among those showing higher MLCK mRNA expression [log10(MLCK/GAPDH) > or =1.4] (87.5 vs. 50.0%; log-rank test, p = 0.021).
  
  
  CONCLUSIONS
  These findings are the first clinical evidence that expression of MLCK is correlated with disease recurrence and distant metastasis in NSCLC.
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Akita University School of Medicine, Akita City, Japan. minamiya@med.akita-u.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Minamiya
authors.forename: Taku
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Saito
authors.forename: Ikuo
authors.initials: I
authors.lastname: Matsuzaki
authors.forename: Kousei
authors.initials: K
authors.lastname: Taguchi
authors.forename: Manabu
authors.initials: M
authors.lastname: Ito
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000556:secondary*; D016022:Case-Control Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009219:Myosin-Light-Chain Kinase / Q000096:biosynthesis* / Q000502:physiology*; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012333:RNA, Messenger; D009219:Myosin-Light-Chain Kinase