Mutated genes are rarely common even in the same pathological type between cancer patients and as such, it has been very challenging to interpret genome sequencing data and difficult to predict clinical outcomes. PIK3CA is one of a few genes whose mutations are relatively popular in tumors. For example, more than 46.6% of luminal-A breast cancer samples have PIK3CA mutated, whereas only 35.5% o...

Deregulation of the phosphatidylinositol 3-kinase (PI3K) pathway either through loss of PTEN or mutation of the catalytic subunit alpha of PI3K (PIK3CA) occurs frequently in human cancer. We identified PIK3CA mutations in 26% of 342 human breast tumor samples and cell lines at about equal frequency in tumor stages I to IV. To investigate the relationship between PTEN and PIK3CA, we generated a ...

Phosphatidylinositol 3-kinases (PI3Ks) are heterodimeric lipid kinases that regulate cellular activities such as proliferation, survival, motility and morphology. Recent studies reported that the p110alpha (PIK3CA), catalytic subunit of PI3-kinase is somatically mutated in human cancers. Hot- spot mutations (E542K, E545K and H1047R) are reported to have higher oncogenic potential. Although PIK3...

PURPOSE Somatic mutations of PIK3CA, which encodes the p110alpha catalytic subunit of phosphatidylinositol 3-kinase, have recently been shown to play an important role in the pathogenesis and progression of human breast cancers. In this study, the frequency of PIK3CA mutations and their relationship with clinicopathologic and biological variables were investigated in Japanese breast cancers. ...

The recent development of human genome studies has demonstrated the possibility of alteration of several genes as oncogenic driver mutations of lung squamous cell carcinoma (SQCC). FGFR1, PIK3CA and SOX2 genes have been recognized as candidate driver genes of SQCC. The aim of the present study was to evaluate FGFR1, PIK3CA and SOX2 protein expression in SQCC and determine whether the expression...

Preclinical data suggest that PIK3CA mutations predict response to PI3K/AKT/mTOR inhibitors. Concomitant KRAS or BRAF mutations may mediate resistance. Therefore, tumors from patients referred to the phase I program for targeted therapy starting in October 2008 were analyzed for PIK3CA mutations using PCR-based DNA sequencing of exons 9 and 20. Consecutive patients with diverse tumor types and ...

Although it has been known that PIK3CA was amplified and PTEN was deficient on protein level in DLBCL, the clinicopathological significance of PIK3CA and PTEN genetic change on DNA level hasn't been established. Here, in our present study, to understand the clinical significance of genetic status of PIK3CA and PTEN in DLBCL, fluorescent in-situ hybridization (FISH) was employed to evaluate the ...

Mutations in PIK3CA are present in 10 to 15% of colorectal carcinomas. We aimed to examine how PIK3CA mutations relate to other molecular alterations in colorectal carcinoma, to pathologic phenotype and survival. PIK3CA mutation testing was carried out using direct sequencing on 757 incident tumors from the Melbourne Collaborative Cohort Study. The status of O-6-methylguanine-DNA methyltransfer...

To understand the impact of PIK3CA mutations on clinical characteristics and treatment response to epidermal growth factor tyrosine kinase inhibitors (EGFR TKIs) of lung adenocarcinoma, we examined PIK3CA and EGFR mutations in lung adenocarcinoma patients, and analyzed their clinical outcomes. Surgically excised tumor, bronchoscopy biopsy/brushing specimens and pleural effusions were prospectiv...