Development and applications of a beta-catenin oligonucleotide microarray: beta-catenin mutations are dominantly found in the proximal colon cancers with microsatellite instability.
beta-catenin mutations have been identified in a variety of human malignancies; most of these are missense mutations restricted at hot-spot areas in exon 3. beta-catenin mutations are known to be highly associated with colorectal cancers with microsatellite instability (MSI). More than 70 beta-catenin mutations have been reported in colorectal cancers, and approximately 90% of beta-catenin mutations have been found in 11 codons (codons 29, 31, 32, 33, 34, 35, 37, 38, 41, 45, and 48) as missense mutations or in-frame deletions. We have developed an oligonucleotide microarray for detecting beta-catenin mutations at these 11 codons. The developed oligonucleotide microarray can detect a total of 110 types of beta-catenin mutations, including the 60 mutations reported previously. Nine beta-catenin mutations were identified in this study by five different methods, i.e., PCR- single-strand conformational polymorphism, denaturing high performance liquid chromatography, direct sequencing, cloning-sequencing, and with an oligonucleotide microarray. All nine of the mutations were identified by denaturing high performance liquid chromatography, cloning-sequencing, and by the oligonucleotide microarray. However, PCR-single-strand conformational polymorphism missed 1 beta-catenin mutation and direct sequencing missed 2. Five beta-catenin mutations from 74 colorectal carcinomas (34 proximal colon cancers and 40 distal colorectal cancers) and 4 beta-catenin mutations from 31 colorectal cancer cell lines (7 from the proximal colon, 6 from the distal colorectum, and 18 unknown) were identified. In colorectal carcinomas, all 5 of the beta-catenin mutations were found in proximal colon tumors. In colorectal cancer cell lines, 2 of 4 cell lines with beta-catenin mutations originated from the proximal colon, and the remaining 2 cell lines were simply described as having originated from the colon. Considering the relationships among beta-catenin mutations, MSI, and tumor location, the frequency of beta-catenin mutations was found to be meaningfully higher in colorectal carcinomas with MSI than in those with microsatellite stability (P < 0.001); moreover, MSI was found to be more frequent in proximal colon tumors (P < 0.01). In addition, beta-catenin mutations were also found to be associated with proximal colon cancer (P = 0.017).
Kim
Il-Jin
IJ
Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi 411-764, Korea.
Kang
Hio Chung
HC
Park
Jae-Hyun
JH
Shin
Yong
Y
Ku
Ja-Lok
JL
Lim
Seok-Byung
SB
Park
So Yeon
SY
Jung
Seung-Yong
SY
Kim
Hark Kyun
HK
Park
Jae-Gahb
JG
D000328:Adult; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D003110:Colonic Neoplasms / Q000235:genetics*; D003598:Cytoskeletal Proteins / Q000235:genetics*; D004252:DNA Mutational Analysis; D043243:DNA Sequence, Unstable; D017353:Gene Deletion; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D020125:Mutation, Missense; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D015534:Trans-Activators / Q000235:genetics*; D051176:beta Catenin
C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051176:beta Catenin