title: Expression of the proto-oncogene c-KIT in normal and tumor tissues from colorectal carcinoma patients.
abstract: OBJECTIVE
  The proto-oncogene c-KIT encodes a tyrosine kinase receptor essential during embryonic development and postnatal life. Although deregulated expression of c-KIT has been reported, its role in colorectal carcinoma remains controversial: some authors have described a correlation between c-KIT expression and colorectal cancer (CRC), while others have failed to detect the receptor in the majority of neoplasia examined. To address this question, we designed a prospective study to analyze the expression of c-KIT in normal and neoplastic colonic mucosa of the same patient.
  
  
  METHODS
  We analyzed the tissues of 20 patients undergoing surgical resection for colorectal carcinoma by reverse transcriptase-polymerase chain reaction, Western blot and immunohistochemistry, whose results were correlated with histopathological parameters.
  
  
  RESULTS
  Most patients (90%) showed c-KIT expression in normal tissue both at RNA and protein level, while in neoplastic tissue it was observed in 30% of patients at RNA level and in 10% at protein level. By immunohistochemistry the localization of c-KIT protein in the normal colon was restricted to interstitial cells scattered in the stroma, whereas the non-neoplastic epithelium was always negative. The mucinous carcinomas were all c-KIT negative, whereas the only case in which c-KIT was displayed in the neoplastic epithelium was a G3 adenocarcinoma.
  
  
  CONCLUSIONS
  Most colorectal carcinomas do not express c-KIT. We suggest that c-KIT expression is rarely present in this neoplasia; thus, the use of receptor inhibitors should be conducted in selected sub-groups of colon carcinoma patients, subsequent to the clear demonstration of c-KIT overexpression in the neoplastic cells.
authors.affiliation: Department of Public Health and Cell Biology, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: Innocenzo
authors.initials: I
authors.lastname: Sammarco
authors.forename: Gabriele
authors.initials: G
authors.lastname: Capurso
authors.forename: Luigi
authors.initials: L
authors.lastname: Coppola
authors.forename: Antonio Paniccià
authors.initials: AP
authors.lastname: Bonifazi
authors.forename: Sara
authors.initials: S
authors.lastname: Cassetta
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Delle Fave
authors.forename: Alessandro
authors.initials: A
authors.lastname: Carrara
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Grassi
authors.forename: Pellegrino
authors.initials: P
authors.lastname: Rossi
authors.forename: Claudio
authors.initials: C
authors.lastname: Sette
authors.forename: Raffaele
authors.initials: R
authors.lastname: Geremia
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015153:Blotting, Western; D002277:Carcinoma / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D000090063:Proto-Oncogene Mas; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D019009:Proto-Oncogene Proteins c-kit