Matches in SemOpenAlex for { <https://semopenalex.org/work/W1560988378> ?p ?o ?g. }
- W1560988378 endingPage "12727" @default.
- W1560988378 startingPage "12715" @default.
- W1560988378 abstract "// Olga V. Leontieva 1 and Mikhail V. Blagosklonny 1 1 Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA Correspondence: Mikhail V. Blagosklonny, email: // Keywords : phorbol ester, PMA, TPA, rapalogs, cancer, mTOR, aging, senescence Received : November 15, 2014 Accepted : December 26, 2014 Published : December 29, 2014 Abstract Phorbol ester (PMA or TPA), a tumor promoter, can cause either proliferation or cell cycle arrest, depending on cellular context. For example, in SKBr3 breast cancer cells, PMA hyper-activates the MEK/MAPK pathway, thus inducing p21 and cell cycle arrest. Here we showed that PMA-induced arrest was followed by conversion to cellular senescence (geroconversion). Geroconversion was associated with active mTOR and S6 kinase (S6K). Rapamycin suppressed geroconversion, maintaining quiescence instead. In this model, PMA induced arrest (step one of a senescence program), whereas constitutively active mTOR drove geroconversion (step two). Without affecting Akt phosphorylation, PMA increased phosphorylation of S6K (T389) and S6 (S240/244), and that was completely prevented by rapamycin. Yet, T421/S424 and S235/236 (p-S6K and p-S6, respectively) phosphorylation became rapamycin-insensitive in the presence of PMA. Either MEK or mTOR was sufficient to phosphorylate these PMA-induced rapamycin-resistant sites because co-treatment with U0126 and rapamycin was required to abrogate them. We next tested whether activation of rapamycin-insensitive pathways would shift quiescence towards senescence. In HT-p21 cells, cell cycle arrest was caused by IPTG-inducible p21 and was spontaneously followed by mTOR-dependent geroconversion. Rapamycin suppressed geroconversion, whereas PMA partially counteracted the effect of rapamycin, revealing the involvement of rapamycin-insensitive gerogenic pathways. In normal RPE cells arrested by serum withdrawal, the mTOR/pS6 pathway was inhibited and cells remained quiescent. PMA transiently activated mTOR, enabling partial geroconversion. We conclude that PMA can initiate a senescent program by either inducing arrest or fostering geroconversion or both. Rapamycin can decrease gero-conversion by PMA, without preventing PMA-induced arrest. The tumor promoter PMA is a gero-promoter, which may be useful to study aging in mammals." @default.
- W1560988378 created "2016-06-24" @default.
- W1560988378 creator A5045764409 @default.
- W1560988378 creator A5081462943 @default.
- W1560988378 date "2014-12-29" @default.
- W1560988378 modified "2023-09-30" @default.
- W1560988378 title "Tumor promoter-induced cellular senescence: cell cycle arrest followed by geroconversion" @default.
- W1560988378 cites W118022590 @default.
- W1560988378 cites W1247773451 @default.
- W1560988378 cites W125786542 @default.
- W1560988378 cites W132728405 @default.
- W1560988378 cites W142520426 @default.
- W1560988378 cites W1497390456 @default.
- W1560988378 cites W1500686771 @default.
- W1560988378 cites W1515444995 @default.
- W1560988378 cites W1515890326 @default.
- W1560988378 cites W1517713315 @default.
- W1560988378 cites W1523693806 @default.
- W1560988378 cites W1566357531 @default.
- W1560988378 cites W1588573809 @default.
- W1560988378 cites W1703681292 @default.
- W1560988378 cites W1838491677 @default.
- W1560988378 cites W1855015466 @default.
- W1560988378 cites W1950663654 @default.
- W1560988378 cites W1957996094 @default.
- W1560988378 cites W1964539952 @default.
- W1560988378 cites W1966453709 @default.
- W1560988378 cites W1967331757 @default.
- W1560988378 cites W1970156452 @default.
- W1560988378 cites W1973300568 @default.
- W1560988378 cites W1974481403 @default.
- W1560988378 cites W1977517636 @default.
- W1560988378 cites W1979262539 @default.
- W1560988378 cites W1982481909 @default.
- W1560988378 cites W1982695619 @default.
- W1560988378 cites W1983757151 @default.
- W1560988378 cites W1986235662 @default.
- W1560988378 cites W1986854615 @default.
- W1560988378 cites W1987445150 @default.
- W1560988378 cites W1987487278 @default.
- W1560988378 cites W1990815825 @default.
- W1560988378 cites W1992920115 @default.
- W1560988378 cites W1995757037 @default.
- W1560988378 cites W1995951924 @default.
- W1560988378 cites W1997143012 @default.
- W1560988378 cites W1998616440 @default.
- W1560988378 cites W1998682097 @default.
- W1560988378 cites W2006436316 @default.
- W1560988378 cites W2010302078 @default.
- W1560988378 cites W2015173256 @default.
- W1560988378 cites W2015613195 @default.
- W1560988378 cites W2022164645 @default.
- W1560988378 cites W2022738422 @default.
- W1560988378 cites W2024449257 @default.
- W1560988378 cites W2031585142 @default.
- W1560988378 cites W2034508560 @default.
- W1560988378 cites W2038566673 @default.
- W1560988378 cites W2038880350 @default.
- W1560988378 cites W2039954115 @default.
- W1560988378 cites W2041308494 @default.
- W1560988378 cites W2041353665 @default.
- W1560988378 cites W2041822035 @default.
- W1560988378 cites W2042063993 @default.
- W1560988378 cites W2042140414 @default.
- W1560988378 cites W2045410669 @default.
- W1560988378 cites W2051955605 @default.
- W1560988378 cites W2052583546 @default.
- W1560988378 cites W2053745915 @default.
- W1560988378 cites W2056059329 @default.
- W1560988378 cites W2056246849 @default.
- W1560988378 cites W2058045514 @default.
- W1560988378 cites W2060450593 @default.
- W1560988378 cites W2060572434 @default.
- W1560988378 cites W2065091721 @default.
- W1560988378 cites W2068482381 @default.
- W1560988378 cites W2070490953 @default.
- W1560988378 cites W2071251338 @default.
- W1560988378 cites W2073965600 @default.
- W1560988378 cites W2076457380 @default.
- W1560988378 cites W2079465474 @default.
- W1560988378 cites W2081067390 @default.
- W1560988378 cites W2085968982 @default.
- W1560988378 cites W2087071824 @default.
- W1560988378 cites W2087404852 @default.
- W1560988378 cites W2094258630 @default.
- W1560988378 cites W2097065668 @default.
- W1560988378 cites W2097122280 @default.
- W1560988378 cites W2099426541 @default.
- W1560988378 cites W2100349150 @default.
- W1560988378 cites W2101388548 @default.
- W1560988378 cites W2107372813 @default.
- W1560988378 cites W2108887402 @default.
- W1560988378 cites W2111463058 @default.
- W1560988378 cites W2112183740 @default.
- W1560988378 cites W2112196790 @default.
- W1560988378 cites W2112444005 @default.
- W1560988378 cites W2113305156 @default.
- W1560988378 cites W2116009473 @default.