The phosphatidylinositol 3-kinase (PI3K) pathway is commonly deregulated in cancer. In recent years, the results of the first phase I clinical trials with PI3K inhibitors have become available. In comparison to other targeted agents such v-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors in melanoma or crizotinib in anaplastic lymphoma receptor tyrosine kinase (ALK) translocated t...

We have investigated the mechanisms of leading edge formation in chemotaxing Dictyostelium cells. We demonstrate that while phosphatidylinositol 3-kinase (PI3K) transiently translocates to the plasma membrane in response to chemoattractant stimulation and to the leading edge in chemotaxing cells, PTEN, a negative regulator of PI3K pathways, exhibits a reciprocal pattern of localization. By unif...

Background: Non-small cell lung cancer (NSCLC), caused by abnormal gene drive, may have primary drug resistance after treatment with tyrosine kinase inhibitors (EGFR-TKIs). Therefore, we explore whether the drug-resistant NSCLC treated EGFR-TKI is related to miR-21/Sonic Hedgehog (SHH)/PI3K/AKT pathway. Methods: The patients from our hospital who meet AJCC TNM staging (7th edition) stage IIIB a...

PURPOSE To determine the mechanisms of action of phosphatidylinositol 3-kinase (PI3K) in lens cell differentiation and survival. METHODS Primary quail lens cell cultures were treated at different stages of differentiation with the PI3K inhibitor LY294002, and expression of survival proteins and differentiation markers were determined by immunoblot analysis. The connection between PI3K regulat...

Phosphatidylinositol 3-kinase (PI3K) promotes cell survival and communication by activating its downstream effector Akt kinase. Here we show that PS1, a protein involved in familial Alzheimer's disease (FAD), promotes cell survival by activating the PI3K/Akt cell survival signaling. This function of PS1 is unaffected by gamma-secretase inhibitors. Pharmacological and genetic evidence indicates ...

Phosphoinositide 3-kinase (PI3K)gamma and Dictyostelium PI3K are activated via G protein-coupled receptors through binding to the Gbetagamma subunit and Ras. However, the mechanistic role(s) of Gbetagamma and Ras in PI3K activation remains elusive. Furthermore, the dynamics and function of PI3K activation in the absence of extracellular stimuli have not been fully investigated. We report that g...

Phosphoinositide 3-kinase (PI3K ) has been implicated in the pathogenesis of asthma, but its mechanism has been considered indirect, through release of inflammatory cell mediators. Because airway smooth muscle (ASM) contractile hyper-responsiveness plays a critical role in asthma, the aim of the present study was to determine whether PI3K can directly regulate contractility of ASM. Immunohistoc...

The class II phosphoinositide 3-kinases (PI3K) PI3K-C2alpha and PI3K-C2beta are two recently identified members of the large PI3K family. Both enzymes are characterized by the presence of a C2 domain at the carboxy terminus and, in vitro, preferentially utilize phosphatidylinositol and phosphatidylinositol 4-monophosphate as lipid substrates. Little is understood about how the catalytic activit...

PURPOSE The objectives of this study were to examine activation patterns of the phosphatidylinositol 3-kinase (PI3K) pathway in gliomas and to examine the prognostic significance of PI3K pathway activation using snap-frozen clinical specimens. MATERIALS AND METHODS Levels of expression of PI3K pathway members were assessed in 92 prospectively collected gliomas through quantitative Western ana...

PURPOSE Aberrant PI3K/AKT/mTOR signaling has been linked to oncogenesis and therapy resistance in various malignancies including leukemias. In Philadelphia chromosome (Ph) positive leukemias, activation of PI3K by dysregulated BCR-ABL tyrosine kinase (TK) contributes to the pathogenesis and development of resistance to ABL-TK inhibitors (TKI). The PI3K pathway thus is an attractive therapeutic ...