Hotspot mutations of PIK3CA and AKT1 genes are absent in multiple myeloma.

The phosphatidylinositol-3-kinases PI3K/AKT pathway regulates many growth and survival mechanisms in the cell, and it has been implicated in development and progression of many human cancers, including multiple myeloma. Recently, many reports have revealed that the PIK3CA gene which encodes the p110 catalytic subunit of PI3K kinase is mutated in many human malignancies. To investigate the oncogenic role of PI3K/AKT pathway in multiple myeloma we sequenced three hot exons: exons 9 and 20 of PIK3CA gene and exon 3 of AKT1 gene in 27 multiple myeloma patients. Our results indicate the absence of the four hot spot mutations E542K, E545K, H1047R and E17K in all studied cases. These findings suggest that PI3K/AKT mutations may not play a major role in multiple myeloma.