title: Novel functional germline variants in the VEGF receptor 2 gene and their effect on gene expression and microvessel density in lung cancer.
abstract: OBJECTIVE
  VEGF receptor 2 (VEGFR-2) plays a crucial role in mediating angiogenic endothelial cell responses via the VEGF pathway, and angiogenesis inhibitors targeting VEGFR-2 are in clinical use. As angiogenesis is a host-driven process, functional heritable variation in KDR, the gene encoding VEGFR-2, may affect VEGFR-2 function and, ultimately, the extent of tumor angiogenesis.
  
  
  METHODS
  We resequenced KDR using 24 DNAs each from healthy Caucasian, African American, and Asian groups. Nonsynonymous genetic variants were assessed for function by phosphorylation assays. Luciferase reporter gene assays were used to examine effects of variants on gene expression. KDR mRNA and protein expression and microvessel density (MVD) were measured in non-small cell lung cancer (NSCLC) tumor samples, and matching patient DNA samples were genotyped to test for associations with variants of interest.
  
  
  RESULTS
  KDR resequencing led to the discovery of 120 genetic variants, of which 25 had not been previously reported. Q472H had increased VEGFR-2 protein phosphorylation and associated with increased MVD in NSCLC tumor samples. -2854C and -2455A increased luciferase expression and associated with higher KDR mRNA levels in NSCLC samples. -271A reduced luciferase expression and associated with lower VEGFR-2 levels in NSCLC samples. -906C and 23408G associated with higher KDR mRNA levels in NSCLC samples.
  
  
  CONCLUSIONS
  This study has defined KDR genetic variation in 3 populations and identified common variants that impact on tumoral KDR expression and vascularization. These findings may have important implications for understanding the molecular basis of genetic associations between KDR variation and clinical phenotypes related to VEGFR-2 function.
authors.affiliation: Department of Medicine, University of Chicago, USA.
authors.forename: Dylan M
authors.initials: DM
authors.lastname: Glubb
authors.forename: Elisa
authors.initials: E
authors.lastname: Cerri
authors.forename: Alexandra
authors.initials: A
authors.lastname: Giese
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Osman
authors.initials: O
authors.lastname: Mirza
authors.forename: Emma E
authors.initials: EE
authors.lastname: Thompson
authors.forename: Peixian
authors.initials: P
authors.lastname: Chen
authors.forename: Soma
authors.initials: S
authors.lastname: Das
authors.forename: Jacek
authors.initials: J
authors.lastname: Jassem
authors.forename: Witold
authors.initials: W
authors.lastname: Rzyman
authors.forename: Mark W
authors.initials: MW
authors.lastname: Lingen
authors.forename: Ravi
authors.initials: R
authors.lastname: Salgia
authors.forename: Fred R
authors.initials: FR
authors.lastname: Hirsch
authors.forename: Rafal
authors.initials: R
authors.lastname: Dziadziuszko
authors.forename: Kurt
authors.initials: K
authors.lastname: Ballmer-Hofer
authors.forename: Federico
authors.initials: F
authors.lastname: Innocenti
mesh_terms: D000704:Analysis of Variance; D001483:Base Sequence; D002289:Carcinoma, Non-Small-Cell Lung / Q000098:blood supply / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005787:Gene Frequency; D005838:Genotype; D018095:Germ-Line Mutation; D057809:HEK293 Cells; D006801:Humans; D007150:Immunohistochemistry; D016014:Linear Models; D008168:Lung / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000098:blood supply / Q000235:genetics* / Q000378:metabolism; D008297:Male; D055806:Microvessels / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation; D020641:Polymorphism, Single Nucleotide; D020133:Reverse Transcriptase Polymerase Chain Reaction; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics* / Q000378:metabolism
chemical_list: D040301:Vascular Endothelial Growth Factor Receptor-2