Čeština
EnglishTumour suppressor PTEN regulates cell cycle and protein kinase B/Akt pathway in breast cancer cells
Hlobilková, Alice; Knillová, J.; Šváchová, M.; Skypalová, P.; Kryštof, Vladimír; Kolář, Z.
ANTICANCER RESEARCH 26 [2A]: 1015-1022, 2006
Keywords: breast cancer cell lines; cell cycle; phosphatase activity
Abstract: PTEN is a tumour suppressor protein with phosphatase activity frequently altered in several types of human cancers. Materials and Methods: The PTEN effect was studied on the cell cycle (by bromdeoxyuridine incorporation) and on the phosphatidylinositol-3-kinaselprotein kinase B/Akt (PI3-K/PKB/Akt) pathway regulating proteins (by immunocytochemical, Western blot analysis and kinase assay) upon transfection of wild-type PTEN and its mutant H123Y in breast cancer cell lines. Results: The expression of the important proteins in the MCF-7 and BT-549 cells was characterised and the cellular localisation of PTEN was analysed. Transfection of H123Y led to the down-regulation of p27(KiP1) and p21(Waf1/Cip1) protein levels and the up-regulation of phosphorylated PKB/Akt. An overexpression of PTEN decreased cyclin E/cdk2 activity and inhibited S-phase entry in MCF-7. In BT-549 these changes were not observed, but overexpression of PTEN led to a diminution of PKB/Akt phosphorylation. Conclusion: PTEN function is mediated through the inhibition of the cell cycle and PKB/Akt phosphorylation in breast cancer cells.
DOI:
IEB authors: bývalý zaměstnanec
ANTICANCER RESEARCH 26 [2A]: 1015-1022, 2006
Keywords: breast cancer cell lines; cell cycle; phosphatase activity
Abstract: PTEN is a tumour suppressor protein with phosphatase activity frequently altered in several types of human cancers. Materials and Methods: The PTEN effect was studied on the cell cycle (by bromdeoxyuridine incorporation) and on the phosphatidylinositol-3-kinaselprotein kinase B/Akt (PI3-K/PKB/Akt) pathway regulating proteins (by immunocytochemical, Western blot analysis and kinase assay) upon transfection of wild-type PTEN and its mutant H123Y in breast cancer cell lines. Results: The expression of the important proteins in the MCF-7 and BT-549 cells was characterised and the cellular localisation of PTEN was analysed. Transfection of H123Y led to the down-regulation of p27(KiP1) and p21(Waf1/Cip1) protein levels and the up-regulation of phosphorylated PKB/Akt. An overexpression of PTEN decreased cyclin E/cdk2 activity and inhibited S-phase entry in MCF-7. In BT-549 these changes were not observed, but overexpression of PTEN led to a diminution of PKB/Akt phosphorylation. Conclusion: PTEN function is mediated through the inhibition of the cell cycle and PKB/Akt phosphorylation in breast cancer cells.
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