Objective—To evaluate molecular abnormalities in
the c-kit gene of canine mast cell tumors (MCT) with
different grades of cellular differentiation.
Sample Population—31 normal tissue specimens
from dogs and 45 canine MCT classified according to
grade of cell differentiation.
Procedure—Genomic DNA extractions were made
from canine MCT and normal tissues. Parts of exon
11, intron 11, and exon 12 of the c-kit gene were
amplified by use of polymerase chain reaction. These
regions were cloned, sequenced, and compared with
GenBank sequences of the National Center for
Biotechnology International. A statistical analysis was
used to compare sequences from canine MCT and
Results—A significantly higher percentage of
homozygous intron 11 deletion was found in canine
MCT (49%) than in normal tissues (13%). This percentage
was also higher in moderately and poorly differentiated
MCT, compared with well-differentiated
MCT. Although no mutations were detected in any of
the specimens, a polymorphism at amino acid position
606 of the canine c-kit sequence was found in all
the studied sequences.
Conclusion and Clinical Relevance—Results indicated
a relationship between intron 11 deletion and
MCT, and the grade of MCT differentiation. We suggest
that intron 11 deletion may be implicated in the
pathogenesis of MCT and could be used as a marker
for diagnosis and prognosis of canine MCT.
(Am J Vet Res 2002;63:1257–1261)