The frequent co-expression of the oncogenes PIK3CA and PAK1 in oral carcinomas.

PIK3CA and PAK1 are critical genes in the PI3K/AKT/PAK pathway. Amplification and strong expression of PIK3CA and PAK1 were identified in around 50% and 88% oral carcinomas, respectively, while co-expression of PIK3CA and PAK1 together was found to be present in 80% of oral carcinomas. PIK3CA and PAK1 amplification was more obvious in recurrent tumors than their primary counterparts. Low grade amplification of PAK1 was prevalent in tumor risk individuals. Knockdown of expression of PIK3CA and PAK1 reduced the oncogenic potential of tumor cells. This study is the first to demonstrate the concordant PIK3CA and PAK1 alterations in oral carcinoma.