Assuntos
Proteínas de Ciclo Celular/genética , Linfoma/genética , Mutação , Proteínas Nucleares/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Linfoma de Burkitt/sangue , Linfoma de Burkitt/genética , Criança , DNA de Neoplasias/sangue , DNA de Neoplasias/genética , Predisposição Genética para Doença , Humanos , Leucemia-Linfoma de Células T do Adulto/sangue , Leucemia-Linfoma de Células T do Adulto/genética , Linfoma/sangue , Mutação Puntual , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangueRESUMO
BACKGROUND: Mutations in the PIK3CA gene (phosphoinositide-3-kinase, catalytic, alpha polypeptide) have recently been described in a number of cancers, and their detection is currently limited because of the low sensitivity of conventional sequencing techniques. METHODS: We combined Amplification Refractory Mutation System (ARMS; AstraZeneca) allele-specific PCR and Scorpions (DxS) to develop assays for tumor-borne PIK3CA mutations and used real-time PCR to develop high-throughput multiplexed assays for the most commonly reported PIK3CA mutants (H1047L, H1047R, E542K, E545K). RESULTS: These assays were more sensitive than sequencing and could detect 5 copies of mutant DNA in proportions as low as 0.1% of the total DNA. We assayed DNA extracted from human tumors and detected PIK3CA mutation frequencies of 10.2% in colorectal cancer, 38.7% in breast cancer, 1.9% in lung cancer, and 2.9% in melanoma. In contrast, sequencing detected only 53% of the mutations detected by our assay. CONCLUSIONS: Multiplexed assays, which can easily be applied to clinical samples, have been developed for the detection of PIK3CA mutations.