Detection of c-kit-activating mutations in gastrointestinal stromal tumors by high-resolution amplicon melting analysis.
High-resolution amplicon melting analysis was used to scan for c-kit-activating mutations in exons 9, 11, 13, and 17 in 29 neoplasms diagnosed as gastrointestinal stromal tumors (GISTs). Immunohistochemically, 7 of 29 did not show strong CD 17 positivity and might represent true smooth muscle tumors or c-kit-negative GISTs. No c-kit-activating mutations were detected in the 7 CD117- cases by high-resolution amplicon melting analysis or direct DNA sequencing. Alterations in the remaining 22 CD117+ cases included 13 (59%) in exon 11, 2 (9%) in exon 9, 1 (5%) in exon 13, and none in exon 17. The genetic alterations consisted of point mutations and in-frame insertions, duplications, and deletions. In exon 11, 7 (54%) of 13 alterations have not been described previously. In 2 cases, the identical exon 11 mutation was observed in the primary tumor and a metastatic/recurrent lesion. In all cases, direct DNA sequencing confirmed that polymerase chain reaction products with an abnormal melting curve contained a mutation and products with a normal melting curve, a normal DNA sequence. High-resolution melting analysis can be used to scan DNA for potential c-kit-activating mutations and can aid in the diagnosis of GISTs.
Willmore
Carlynn
C
Department of Pathology, University of Utah, Salt Lake City 84108, USA.
Holden
Joseph A
JA
Zhou
Luming
L
Tripp
Sheryl
S
Wittwer
Carl T
CT
Layfield
Lester J
LJ
D000595:Amino Acid Sequence; D004252:DNA Mutational Analysis; D017931:DNA Primers; D004250:DNA Topoisomerases, Type II / Q000096:biosynthesis; D005770:Gastrointestinal Neoplasms / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009154:Mutation; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D016133:Polymerase Chain Reaction; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D017154:Stromal Cells / Q000473:pathology*; D044366:Transition Temperature
D017931:DNA Primers; D019009:Proto-Oncogene Proteins c-kit; D004250:DNA Topoisomerases, Type II