TY - JOUR
T1 - Advances in Brief
T2 - Antibody to ras Proteins in Patients with Colon Cancer
AU - Takahashi, Masazumi
AU - Chen, Wei
AU - Byrd, David R.
AU - Disis, Mary L.
AU - Huseby, Eric S.
AU - Qin, Huilian
AU - McCahill, Larry
AU - Nelson, Heidi
AU - Shimada, Hiroshi
AU - Okuno, Kiyotaka
AU - Yasutomi, Masayuki
AU - Peace, David J.
AU - Cheever, Martin A.
PY - 1995/10/1
Y1 - 1995/10/1
N2 - The current study examined sera from 160 colon cancer patients and 60 normal individuals to determine whether antibody to mutated p21 ras protein was present. Studies focused on the aspartic acid substitution at amino acid position 12 (denoted D12), one of the most common mutations in colon adenocarcinoma. IgA antibodies directed against mutated p21 ras-D12 protein were detected in 51 (32%) of 160 colon cancer patients, but only in 1 (2.5%) of 40 normal individuals. The greater incidence of antibody in cancer patients provides presumptive evidence that immunization to the ras proteins occurred as a result of the malignancy. Examination of sera for antibody reactivity to wild-type p21 ras protein (denoted p21 ras-G12) as well as p21 ras proteins bearing the D12, V12, S12, or L61 mutations showed that antibody detected was largely to normal segments of the p21 ras protein. Epitope mapping, using peptide neutralization assays with mutated or normal ras peptides as competitors, demonstrated that in 10 (67%) of 15 sera examined the antibody reactivity to p21 ras-G12 protein was neutralized by peptides near the carboxyl terminus of p21 ras protein, but not by peptides spanning the specific point mutation region. Antibody reactivities correlated with peripheral blood lymphocyte count, but did not correlate with patient age, sex, histology, stage, tumor locus, lymph node metastasis, or serum carcinoembryonic antigen.
AB - The current study examined sera from 160 colon cancer patients and 60 normal individuals to determine whether antibody to mutated p21 ras protein was present. Studies focused on the aspartic acid substitution at amino acid position 12 (denoted D12), one of the most common mutations in colon adenocarcinoma. IgA antibodies directed against mutated p21 ras-D12 protein were detected in 51 (32%) of 160 colon cancer patients, but only in 1 (2.5%) of 40 normal individuals. The greater incidence of antibody in cancer patients provides presumptive evidence that immunization to the ras proteins occurred as a result of the malignancy. Examination of sera for antibody reactivity to wild-type p21 ras protein (denoted p21 ras-G12) as well as p21 ras proteins bearing the D12, V12, S12, or L61 mutations showed that antibody detected was largely to normal segments of the p21 ras protein. Epitope mapping, using peptide neutralization assays with mutated or normal ras peptides as competitors, demonstrated that in 10 (67%) of 15 sera examined the antibody reactivity to p21 ras-G12 protein was neutralized by peptides near the carboxyl terminus of p21 ras protein, but not by peptides spanning the specific point mutation region. Antibody reactivities correlated with peripheral blood lymphocyte count, but did not correlate with patient age, sex, histology, stage, tumor locus, lymph node metastasis, or serum carcinoembryonic antigen.
UR - http://www.scopus.com/inward/record.url?scp=0028832188&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028832188&partnerID=8YFLogxK
M3 - Article
C2 - 9815896
AN - SCOPUS:0028832188
SN - 1078-0432
VL - 1
SP - 1071
EP - 1077
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 10
ER -