The rate of PIK3CA mutation between different cancers in Iranian population

PI3Ks are heterodimeric kinases involved in the control of cellular growth, transformation,adhesion, and apoptosis. PIK3CA gene encodes the catalytic subunit p110 alpha of PI3K andit is located in chromosome 3 (3q26) and it has 20 exon. Mutations of catalytic subunit canincrease the enzyme activity and cause uncontrolled growth of the cells and finally resultsarising cancerous cell .Recently, high frequencies of somatic mutations in the PIK3CA genehave been reported in several human cancer types including colon, brain, stomach, breast,and ovary. More than %90 of PIK3CA mutation occur in exon9(the helical domain) andexon20( kinase domains).In our study we describe and comprise mutation rate of exon9 and20 of PIK3CA gene in colorectal cancer, breast cancer, and endometrial cancer. Themutation was surveyed by single-strand conformational polymorphism (SSCP) and directDNA sequencing. The frequency of PIK3CA mutation in colorectal cancer, breast cancer andendometrial cancer was 40%, 14% and 47% respectively. The correlation of mutation andpathologic factors were analyzed by SPSS and some of the pathologic factors like lymphnode involvement, stage and metastasis have positive association with some of these cancers.