title: Serum lemur tyrosine kinase-3: a novel biomarker for screening primary non-small cell lung cancer and predicting cancer progression.
abstract: OBJECTIVE
  We aimed to determine the expression level of serum soluble lemur tyrosine kinase-3 (sLMTK3) in human non-small cell lung cancer (NSCLC), and to examine whether the s sLMTK3 level could be used as a biomarker to screen primary NSCLC and to predict lung cancer progression.
  
  
  METHODS
  Serum levels of sLMTK3 in 67 patients with primary NSCLC, 28 patients with lung benign lesion, and 53 healthy volunteers were measured by sandwich ELISA. LMTK3 protein expression in NSCLC tissues and normal lung tissues was also detected by using immunohistochemical staining. Receiver operating characteristic (ROC) curve was selected to evaluate the sensitivity and the specificity of serum sLMTK3 level.
  
  
  RESULTS
  The mean concentration of sLMTK3 in NSCLC group was significantly higher than in the lung benign lesion group (P < 0.001) and the healthy control group (P < 0.001). Higher sLMTK3 level was correlated with age (P = 0.013), tumor-node-metastasis (TNM) stage (P < 0.001), and lymph node metastasis (P < 0.001) of NSCLC. In contrast to the normal lung tissues, increased LMTK3 expression was found in the NSCLC tissues, and was mainly located on the cytoplasm and the nuclei of cancer cells. For separating NSCLC from control group, the corresponding areas under the ROC curve (AUC) were 0.947 for sLMTK3 and 0.804 for CEA. With cutoffs of 10.05 ng/ml for sLMTK3 and 5.0 ng/ml for CEA respectively, the sensitivity and the specificity of sLMTK3 and CEA were, 80.60% and 97.53%, 35.82% and 96.30%, respectively, indicating better diagnostic value of sLMTK3.
  
  
  CONCLUSIONS
  The sLMTK3 level was significantly increased in human NSCLC, and could be used as a potential and valuable biomarker for screening primary NSCLC and for predicting the progression of patients with this malignancy.
authors.affiliation: Department of Respiratory, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Kexin
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Tumor Biological Treatment, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Lujun
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Tumor Biological Treatment, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Deng
authors.affiliation: Department of Respiratory, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Yongyi
authors.initials: Y
authors.lastname: Zou
authors.affiliation: Department of Tumor Biological Treatment, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Tumor Biological Treatment, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Shi
authors.affiliation: Department of Tumor Biological Treatment, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.affiliation: Department of Tumor Biological Treatment, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Mingyang
authors.initials: M
authors.lastname: Lu
authors.affiliation: Department of Respiratory, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Tumor Biological Treatment, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Jingting
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of Respiratory, Third Affiliated Hospital of Soochow University Changzhou 213003, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000032:analysis*; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology / Q000401:mortality / Q000473:pathology*; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000201:enzymology / Q000401:mortality / Q000473:pathology*; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis / Q000097:blood*; D008875:Middle Aged; D011379:Prognosis; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000097:blood*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D008565:Membrane Proteins; C560359:LMTK3 protein, human; D017346:Protein Serine-Threonine Kinases
keywords: Lemur tyrosine kinase-3; estrogen receptor; non-small cell lung cancer; tumor biomarker