title: Defensin alpha 6 (DEFA 6) overexpression threshold of over 60 fold can distinguish between adenoma and fully blown colon carcinoma in individual patients.
abstract: BACKGROUND
  It is known that alpha-defensin expression is enhanced in colon cancer. However, the expression of human alpha defensin 6 (DEFA 6) in earlier stages, such as adenoma, has so far not yet been studied in a patient resolved manner.
  
  
  METHODS
  By using quantitative Real Time-PCR, the gene expression pattern of DEFA 1-3 and DEFA 6 was analyzed in tissue of different stages of carcinogenesis, derived from colorectal cancer patients. In addition to paired normal and tumor tissue, matched normal near tumor and adenoma tissue samples were examined.
  
  
  RESULTS
  The median gene expression of human defensin alpha 6 (DEFA 6) has been found to be moderately increased (~ 5 fold) in tumor samples derived from individuals with colorectal cancer (CRC) when compared to their normal counterparts. However, when the data were analyzed in a patient-wise manner, a large expression variation among individual patients is found, making the use of DEFA 6 for individual diagnosis of fully blown colon carcinoma difficult. Surprisingly, in adenoma the gene expression analysis revealed a 100 fold increased median expression of DEFA 6 relative to normal colon tissue. 13/18 samples had an individual overexpression of more than 60 fold in adenoma but only 3/17 in carcinoma. In each of the individual patients, at least either the adenoma or the carcinoma showed strong DEFA 6 overexpression.
  
  
  CONCLUSIONS
  We suggest that the expression of DEFA 6 preferably can be used as a potential diagnostic marker for adenoma and not as a marker for fully blown carcinoma. This is supported by the fact that DEFA 6 is a downstream target of the Wnt pathway, which is mutational active during the earliest stage of cancer development.
authors.affiliation: Leibniz Institute for Age Research - Fritz Lipmann Institute, Beutenbergstr 11, 07745 Jena, Germany. mradeva@fli-leibniz.de
authors.forename: Mariya Y
authors.initials: MY
authors.lastname: Radeva
authors.forename: Franziska
authors.initials: F
authors.lastname: Jahns
authors.forename: Anne
authors.initials: A
authors.lastname: Wilhelm
authors.forename: Michael
authors.initials: M
authors.lastname: Glei
authors.forename: Utz
authors.initials: U
authors.lastname: Settmacher
authors.forename: Karl Otto
authors.initials: KO
authors.lastname: Greulich
authors.forename: Henning
authors.initials: H
authors.lastname: Mothes
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000378:metabolism*; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis* / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D004252:DNA Mutational Analysis; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008875:Middle Aged; D051153:Wnt Proteins / Q000378:metabolism; D023084:alpha-Defensins / Q000096:biosynthesis*
chemical_list: C517765:DEFA6 protein, human; D051153:Wnt Proteins; D023084:alpha-Defensins