title: Epidermal growth factor receptor expression in gastric tumors and its relationship with the germline polymorphisms - 216 G>T, -191 C>A, (CA) n IVS1, and R521K.
abstract: BACKGROUND
  Gastric cancer (GC) is the third worldwide leading cause of cancer-related death affecting both sexes. The aberrant expression of epidermal growth factor receptor (EGFR) gene has been detected in many human epithelial malignancies and linked to advanced disease, more aggressive phenotype, and poor prognosis.
  
  
  OBJECTIVE
  To analyze the relation that the expression of EGFR in gastric tumors holds with pathological characteristics and with the germline polymorphisms -216 G>T, -191 C>A, (CA) n IVS1, and R521K.
  
  
  METHODS
  We studied 22 biopsies from gastric tumors obtained by endoscopy. EGFR expression was determined by relative quantification real-time polymerase chain reaction with the glyceraldehyde-3-phosphate dehydrogenase reference gene (as for messenger RNA [mRNA]) and by immunohistochemistry (IHC) (as for protein). EGFR germline polymorphisms were analyzed by sequencing, GeneScan, and restriction fragment length polymorphisms.
  
  
  RESULTS
  EGFR mRNA expression was increased (>2-fold) in 13.6% of GC cases, decreased (<0.5-fold) in 68.2%, and normal in 18.2%; overexpression was related to well-differentiated gastric tumors, whereas underexpression was linked to moderate or poorly differentiated gastric tumors (P < 0.001). EGFR protein expression was high (IHC 2+ and 3+) in 29.4% of gastric tumors and was normal or low (score 0 to 1+) in 70.6% cases. EGFR expression, in both mRNA and protein, was not related to any EGFR polymorphism (P > 0.05).
  
  
  CONCLUSIONS
  Most gastric tumors showed low EGFR expression (mRNA and protein), whereas EGFR overexpression was related to well-differentiated gastric tumors. Furthermore, germinal polymorphisms -216, -191, (CA) n IVS1, and R521K were not related to EGFR expression (mRNA or protein).
authors.affiliation: División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social; Doctorado en Genética Humana, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Nextipac, Jalisco, ; Departamento de Ciencias Biológicas, División de Ciencias Biológicas y de la Salud, Centro Universitario de la Costa, Universidad de Guadalajara, Delegación Ixtapa, Puerto Vallarta, México.
authors.forename: J H
authors.initials: JH
authors.lastname: Torres-Jasso
authors.affiliation: División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social; Doctorado en Genética Humana, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Nextipac, Jalisco, México.
authors.forename: A R
authors.initials: AR
authors.lastname: Bustos-Carpinteyro
authors.affiliation: División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, México.
authors.forename: J R
authors.initials: JR
authors.lastname: Garcia-Gonzalez
authors.affiliation: Departamento de Biología Celular y Molecular, Laboratorio de Inmunobiología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Nextipac, Jalisco, México.
authors.forename: J
authors.initials: J
authors.lastname: Peregrina-Sandoval
authors.affiliation: Departamento de Enseñanza y Capacitación, Instituto Jalisciense de Cancerología, Guadalajara, México.
authors.forename: J A
authors.initials: JA
authors.lastname: Cruz-Ramos
authors.affiliation: Departamento de Gastroenterología, Servicio de Endoscopías, Hospital de Especialidades del Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social, México.
authors.forename: E
authors.initials: E
authors.lastname: Santiago-Luna
authors.affiliation: División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, México.
authors.forename: J Y
authors.initials: JY
authors.lastname: Sanchez-Lopez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D018095:Germ-Line Mutation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D060888:Real-Time Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
chemical_list: C512478:EGFR protein, human; D066246:ErbB Receptors