Pathol Res Pract  2000;196(9):601-5 

Ras oncogenes and p53 tumor suppressor gene analysis in cardiac myxomas.

Karga H, Papaioannou P, Karayianni M, Papadimitriou K, Priftis D, Voujuklakis T,
Migdou B, Nanas J, Papapetrou P.

Endocrine Unit, Alexandra Hospital, Athens, Greece.

Although ras oncogenes and p53 tumor suppressor gene mutations are implicated in
the development of several human tumors, little is known about their role in the
pathogenesis of primary cardiac tumors. Paraffin-embedded tissue from 19 cardiac
myxomas were investigated for the presence of ras oncogenes and p53 tumor
suppressor gene abnormalities. Immunohistochemical analysis was used to identify
the accumulation of p21-ras and p53 proteins. A polymerase chain reaction was
used to amplify exons 1 and 2 of the ras genes and exons 5 to 8 of the p53 gene.
The PCR products were analyzed by single strand conformation polymorphism
analysis and by direct DNA sequencing. Three of 19 myxomas showed strong
positive staining for the ras p21 protein. In contrast, nuclear p53 was not
detectable in any of the myxomas. Among the ras p21 immunopositive myxomas, 2
were heterozygous for a missense point mutation of the K-ras, Gly 12Asp. Further
screening of the remaining myxomas showed no mutation or even silent
polymorphism in any exon of the ras and p53. The results suggest that although
genetic alterations of ras oncogenes and p53 are uncommon events in cardiac
myxomas, ras mutations may be involved in the pathogenesis of a subgroup of this
type of tumor.

PMID: 10997733 [PubMed - indexed for MEDLINE]