These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: ROS-generating oxidases Nox1 and Nox4 contribute to oncogenic Ras-induced premature senescence.
    Author: Kodama R, Kato M, Furuta S, Ueno S, Zhang Y, Matsuno K, Yabe-Nishimura C, Tanaka E, Kamata T.
    Journal: Genes Cells; 2013 Jan; 18(1):32-41. PubMed ID: 23216904.
    Abstract:
    Activated oncogenes induce premature cellular senescence, a permanent state of proliferative arrest in primary rodent and human fibroblasts. Recent studies suggest that generation of reactive oxygen species (ROS) is involved in oncogenic Ras-induced premature senescence. However, the signaling mechanism controlling this oxidant-mediated irreversible growth arrest is not fully understood. Here, we show that through the Ras/MEK pathway, Ras oncogene up-regulated the expression of superoxide-generating oxidases, Nox1 in rat REF52 cells and Nox4 in primary human lung TIG-3 cells, leading to an increase in intracellular level of ROS. Ablation of Nox1 and Nox4 by small interfering RNAs (siRNAs) blocked the RasV12 senescent phenotype including β-galactosidase activity, growth arrest and accumulation of tumor suppressors such as p53 and p16Ink4a. This suggests that Nox-generated ROS transduce senescence signals by activating the p53 and p16Ink4a pathway. Furthermore, Nox1 and Nox4 siRNAs inhibited both Ras-induced DNA damage response and p38MAPK activation, whereas overexpression of Nox1 and Nox4 alone was able to induce senescence. The involvement of Nox1 in Ras-induced senescence was also confirmed with embryonic fibroblasts derived from Nox1 knockout mice. Together, these findings suggest that Nox1- and Nox4-generated ROS play an important role in Ras-induced premature senescence, which may involve DNA damage response and p38MAPK signaling pathways.
    [Abstract] [Full Text] [Related] [New Search]