E-cadherin gene alterations in gastric cancers in different ethnic populations.
BACKGROUND
A retrospective study of nucleotide sequence alterations in exons 7-9 of the E-cadherin gene and expression of E-cadherin and beta-catenin in gastric tumors from African American, Asian, Causcasian and Hispanic patients was carried out to determine differences potentially related to race/ethnicity in these groups.


METHODS
Paraffin-embedded tissue sections archived at the Memorial Sloan Kettering Cancer Center were used for immunohistochemical staining of sections for membranous E-cadherin protein and nuclear localization of beta-catenin. DNA from tumor tissue extracted from the paraffin sections was used as template for amplification of the E-cadherin gene exonic regions.


RESULTS
Sequence analyses of the high-frequency mutation region along E-cadherin exons 7-9 revealed a number sequence alterations in the patient group as a whole, mostly within exon 8. The alterations were mainly single nucleotide insertions, but a palindromic duplication of exon 8 in a Caucasian patient and several extragenic insertions in a Hispanic and an African American patient were also found. Nuclear localization of beta-catenin was correlated with inactivating sequence alterations in three patients.


CONCLUSIONS
Exon 8 was found to display the most extensive alterations in all the groups studied. As a group, the most extensive sequence alterations were found in tumors from Caucasian patients. A finding of potential significance as a biomarker related to ethnicity was a C insertion at nt 76,598 found independently in two African American patients.
Steinberg
Mark L
ML
Department of Chemistry, The City College of New York, Convent Ave and 138th St, New York, NY 10031, USA. marste@sci.ccny.cuny.edu
Hwang
Bor-Jang
BJ
Tang
Laura
L
Shah
Manish A
MA
D001741:Black or African American; D001213:Asian; D014408:Biomarkers, Tumor / Q000235:genetics; D015820:Cadherins / Q000235:genetics*; D005091:Exons; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D009154:Mutation; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D013274:Stomach Neoplasms / Q000208:ethnology* / Q000235:genetics*; D044465:White People
D014408:Biomarkers, Tumor; D015820:Cadherins