title: Gene expression pattern of the epidermal growth factor receptor family and LRIG1 in renal cell carcinoma.
abstract: BACKGROUND
  Previous studies have revealed altered expression of epidermal growth factor receptor (EGFR)-family members and their endogenous inhibitor leucine-rich and immunoglobulin-like domains 1 (LRIG1) in renal cell carcinoma (RCC). In this study, we analyzed the gene expression levels of EGFR-family members and LRIG1, and their possible associations with clinical parameters in various types of RCC.
  
  
  METHODS
  Gene expression levels of EGFR-family members and LRIG1 were analyzed in 104 RCC samples, including 81 clear cell RCC (ccRCC), 15 papillary RCC (pRCC), and 7 chromophobe RCC (chRCC) by quantitative real-time RT-PCR. Associations between gene expression levels and clinical data, including tumor grade, stage, and patient survival were statistically assessed.
  
  
  RESULTS
  Compared to kidney cortex, EGFR was up-regulated in ccRCC and pRCC, LRIG1 and ERBB2 were down-regulated in ccRCC, and ERBB4 was strongly down-regulated in all RCC types. ERBB3 expression did not differ between RCC types or between RCC and the kidney cortex. The expression of the analyzed genes did not correlate with patient outcome.
  
  
  CONCLUSIONS
  This study revealed that the previously described up-regulation of EGFR and down-regulation of ERBB4 occurred in all analyzed RCC types, whereas down-regulation of ERBB2 and LRIG1 was only present in ccRCC. These observations illustrate the need to evaluate the different RCC types individually when analyzing molecules of interest and potential biological markers.
authors.affiliation: Department of Radiation Sciences, Umeå University, SE-901 87, Umeå, Sweden. marcus.thomasson@onkologi.umu.se
authors.forename: Marcus
authors.initials: M
authors.lastname: Thomasson
authors.forename: Håkan
authors.initials: H
authors.lastname: Hedman
authors.forename: Börje
authors.initials: B
authors.lastname: Ljungberg
authors.forename: Roger
authors.initials: R
authors.lastname: Henriksson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000235:genetics; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D052138:Genes, Neoplasm / Q000235:genetics; D006801:Humans; D007672:Kidney Cortex / Q000378:metabolism / Q000473:pathology; D007680:Kidney Neoplasms / Q000235:genetics*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D005810:Multigene Family / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000235:genetics* / Q000378:metabolism
chemical_list: C484445:LRIG1 protein, human; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; C512478:EGFR protein, human; D066246:ErbB Receptors