The phosphatase and tensin homologue deleted on chromosome 10 (PTEN) negatively regulates cell survival and proliferation mediated by phosphoinositol 3 kinases. We have explored the role of the phosphoinositol(3,4,5)P3-phosphatase PTEN in T cell development by analyzing mice with a T cell-specific deletion of PTEN. Pten(flox/flox)Lck-Cre mice developed thymic lymphomas, but before the onset of ...

Purpose: Analytically validated assays to interrogate biomarker status in clinical samples are crucial for personalized medicine. PTEN is a tumor suppressor commonly inactivated in prostate cancer that has been mechanistically linked to disease aggressiveness. Though deletion of PTEN, as detected by cumbersome FISH spot counting assays, is associated with poor prognosis, few studies have valida...

The mechanism of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance in cancer cells is not fully understood. Here, we show that the Akt survival pathway plays an important role in TRAIL resistance in human cancer cells. Specifically, we found that TRAIL treatment activates the Akt survival pathway and that inhibition of this pathway by the PI3K inhibitor LY294002 or knoc...

BACKGROUND Abnormalities of PTEN, a candidate tumor suppressor gene located at 10q23.3, play an important role in the tumorigenesis of multiple tumor types. OBJECTIVES To investigate the expression of PTEN and its clinical implication in squamous cell carcinoma of the tongue. DESIGN Retrospective analysis of PTEN protein expression in archived primary oral tongue tumor samples. SETTING Ac...

OBJECTIVE To investigate, in vitro, the regulatory effects of tumor-suppressing gene PTEN on mTOR (mammalian target of rapamycin) signaling pathway, the effects of transfected PTEN and rapamycin on the growth inhibition, and apoptosis induction for human leukemia cell line K562 cells. METHODS K562 cells were transfected with recombined adenovirus-PTEN vector containing green fluorescent prote...

PURPOSE Hyperactivation of the phosphatidylinositol 3-kinase/Akt signaling through disruption of PTEN function is common in glioblastoma multiforme, and these genetic changes are predicted to enhance sensitivity to mammalian target of rapamycin (mTOR) inhibitors such as RAD001 (everolimus). EXPERIMENTAL DESIGN To test whether PTEN loss could be used as a predictive marker for mTOR inhibitor s...

The tumor suppressor PTEN regulates cell migration, growth, and survival by removing the 3'-phosphate of phosphoinositides. Exposure of purified PTEN or of cells to H(2)O(2) resulted in inactivation of PTEN in a time- and H(2)O(2) concentration-dependent manner. Analysis of various cysteine mutants, including mass spectrometry of tryptic peptides, indicated that the essential Cys(124) residue i...

The importance of PTEN (phosphatase and tensin homolog located on chromosome 10) in cancer has surpassed all predictions and expectations from the time it was discovered and has qualified this gene as one of the most commonly mutated and deleted tumor suppressors in human cancer. PTEN levels are frequently found downregulated in cancer, even in the absence of genetic loss or mutation. PTEN is h...

The failure of an osseous fracture to heal (development of a non-union) is a common and debilitating clinical problem. Mice lacking the tumor suppressor Pten in osteoblasts have dramatic and progressive increases in bone volume and density throughout life. Since fracture healing is a recapitulation of bone development, we investigated the process of fracture healing in mice lacking Pten in oste...

Phosphatase and tensin homolog deleted on chromosome ten (PTEN ) is a human suppressor gene. Its protein product is a bispecific phosphatase playing the complex role in the cell cycle regulating processes and apoptosis by the mechanism of signal transduction into the cell via tyrosine kinase B signaling pathway (PI3K/Akt/mTOR). Reduction or loss of PTEN function is implicated in the pathogenesi...