High Frequency of Mutations of the PIK3CA Gene in Human Cancers.

Phosphatidylinositol 3-kinases (PI3Ks) are lipid kinases that regulate signaling pathways important for neoplasia, including cell proliferation, adhesion, survival, and motility. To determine if PI3Ks are genetically altered in tumorigenesis, researchers sequenced PI3K genes in human cancers and corresponding normal tissue. They initially examined the sequences of 117 exons that encode the predicted kinase domains of these genes in 35 colorectal cancers. Mutations in PIK3CA were also identified in 4 of 15 glioblastomas, 3 of 12 gastric cancers, 1 of 12 breast cancers and 1 of 24 lung cancers.