y of GSK 3B is controlled by phosphorylation it maintains it in an inactive form

cells infected with lenti PTEN caught in size, sending restoration of cell size checkpoint control. These data implicate PTEN in the control of GBM cell size arrest which was induced with a clinically relevant chemotherapeutic drug. Oncogenic PIK3CA fails to effectively modulate Afatinib cell size check-point control. We wondered whether abrogation of rays induced cell size gate was a feature of activation of PI3K signaling. To try this, we studied PIK3CA gene targeted derivatives of HCT116 cells, which harbor an endogenous heterozygous oncogenic mutation in the catalytic domain of PIK3CA. Human somatic cell gene targeting technology was used to generate types of HCT116 cells by which either the mutant allele or the wild type allele of PIK3CA have been deleted. Derivatives and adult HCT116 cells lacking Cellular differentiation either the wild type or mutant allele of PIK3CA were treated with 6 Gy IR and examined 6 days after irradiation. In contrast to HCT116 PTEN cells, each of the three otherwise isogenic PIK3CA gene targeted cell lines was able to effortlessly charge its cell size, despite the power of oncogenic PIK3CA to manage the phosphorylation state and action of Akt in these cells. These data indicated that unlike PTEN, PIK3CA appears not to be involved in regulation of the IR induced cell size checkpoint. Additionally, these suggested the power of PTEN to manage intracellular levels of PIP2 and PIP3 is not its only bio-chemical activity needed for cell size checkpoint control. The lipid phosphatase activity of PTEN is important for cell size check-point control. The fact lenti PTEN was able to restore cell size checkpoint control to PTEN deficient human cells presented us with the experimental program for evaluating the result of PTEN mutations on cell size checkpoint control. Initially, we applied site directed mutagenesis to introduce 11 different tumefaction derived mutations to the known HSP90 Inhibitor functional domains of PTEN. The roots of the mutations and their previously determined effects on PTEN lipid phosphatase activity are listed in Fig. 5D. The constructs were then packaged into infectious lentivirus and used to invade HCT116 PTEN cells. Western blotting was performed to confirm expression of PTEN and to measure the effects of mutant PTEN proteins on modulation of p Akt. In addition, infected cells were treated with 6 Gy IR and cultured for 6 days. The cell size was then calculated employing a Multisizer III. Three of the 11 strains are recognized to disrupt the lipid phosphatase activity of PTEN. These mutants were unable to downregulate quantities of p Akt in PTEN deficient cells, as expected. Similarly, these three mutant proteins were completely unable to restore size checkpoint control to HCT116 PTEN cells. Depending on these data, we figured the lipid phosphatase activity of PTEN is essential for effective PTEN dependent cell size check-point get a handle on.