Mutations of PIK3CA are rare in cutaneous melanoma.

Abstract

Recent studies have shown that the PIK3CA gene, which encodes the p110alpha catalytic subunit of phosphatidylinositol 3-kinases, is mutated in human cancers. To determine whether PIK3CA is altered in cutaneous melanoma, we screened a series of 101 melanoma metastases. We identified PIK3CA missense mutations in three metastases (3%). Interestingly, these mutations were observed only in tumours that were negative for NRAS mutations. Using immunohistochemistry, we also analysed our metastases for the expression of phosphorylated Akt. These analyses revealed a moderate to strong phosphorylated Akt expression in 78% (21 of 27) of metastases with NRAS mutations and in 73% (54 of 74) of metastases without NRAS mutations. Interestingly, the three metastases with mutations in PIK3CA all exhibited a strong expression of phosphorylated Akt. Taken together, our results show that PIK3CA is mutated in a minority of melanomas and suggest that mutations in this gene may represent an alternative mechanism of Akt activation in cutaneous melanoma.

• Authors: Katarina Omholt, Doris Kröckel, Ulrik Ringborg, Johan Hansson
• Journal: Melanoma research (Melanoma Res) Vol. 16 Issue 2 Pg. 197-200 (Apr 2006) ISSN: 0960-8931 [Print] England
• PMID: 16567976 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Phosphatidylinositol 3-Kinases
• Class I Phosphatidylinositol 3-Kinases
• PIK3CA protein, human
• Oncogene Protein v-akt

Topics

• Class I Phosphatidylinositol 3-Kinases
• DNA Mutational Analysis
• Female
• Humans
• Immunohistochemistry
• Male
• Melanoma (genetics, secondary)
• Mutation, Missense
• Oncogene Protein v-akt (metabolism)
• Phosphatidylinositol 3-Kinases (genetics)
• Phosphorylation
• Polymerase Chain Reaction
• Polymorphism, Single-Stranded Conformational
• Skin Neoplasms (genetics, pathology)