title: MDK Protein Overexpression Correlates with the Malignant Status and Prognosis of Non-small Cell Lung Cancer.
abstract: OBJECTIVE
  Midkine (MDK) is a heparin-binding growth factor and is overexpressed in various types of human cancer. However, little is known about the clinical significance of MDK in non-small cell lung cancer (NSCLC). The aim of this study was to measure MDK protein levels in patients with NSCLC and to explore its clinical significance.
  
  
  METHODS
  The expression status of MDK in NSCLC at Gene Expression Omnibus (GEO accession number: GSE19804) was observed. The expression of MDK mRNA and protein was examined in NSCLC tissues and normal lung tissues through real-time PCR and Western blot. Meanwhile, the relationship of MDK protein expression levels with clinical characteristics of 186 NSCLC patients was analyzed by immunohistochemistry.
  
  
  RESULTS
  MDK expression was increased in NSCLC tissues compared with paired normal lung tissues in microarray data (GSE19804). MDK mRNA and protein expression were obviously increased in NSCLC tissues than in paired adjacent normal lung tissues. Using immunohistochemistry, MDK protein overexpression was positively correlated with status of clinical stage, T classification, N classification, and M classification in NSCLC patients. In survival analysis, patients with higher MDK protein expression had a significantly shorter overall survival time than did patients with lower MDK protein expression. Multivariate analysis indicated that the MDK protein overexpression was an independent poor prognostic indicator for patients with NSCLC.
  
  
  CONCLUSIONS
  MDK plays an important role in NSCLC progression and prognosis and may act as a convincing prognostic indicator for NSCLC patients.
authors.affiliation: Department of Oncology, Yan'an Hospital of Kunming City, Yan'an Hospital of Kunming Medical University, Kunming, China.
authors.forename: Kehua
authors.initials: K
authors.lastname: Yuan
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Medical Oncology, The First Affiliated Hospital of Kunming Medical University, Kunming, China.
authors.forename: Chang E
authors.initials: CE
authors.lastname: Gao
authors.affiliation: Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China.
authors.forename: Gaofeng
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Guo
authors.affiliation: Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China.
authors.forename: Yiqin
authors.initials: Y
authors.lastname: Ai
authors.affiliation: Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China. Electronic address: kmzhming@163.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D018450:Disease Progression; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000473:pathology; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D000078792:Midkine; D009414:Nerve Growth Factors / Q000096:biosynthesis* / Q000235:genetics; D011379:Prognosis; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D016207:Cytokines; C066254:MDK protein, human; D009414:Nerve Growth Factors; D012333:RNA, Messenger; D000078792:Midkine
keywords: Immunohistochemistry; MDK; NSCLC; Prognosis