Abstract 2483: Inhibition of the polycomb group gene EZH2 suppresses growth and radiosensitizes ATRT cells by promoting senescence and inhibiting the CycinD-E2F1 axis

• Published in: Cancer research (Chicago, Ill.) Vol. 72; no. 8_Supplement; p. 2483
• Main Authors: Alimova, Irina N., Venkataraman, Sujatha, Harris, Peter, Marquez, Victor E., Birks, Diane, Foreman, Nicholas K., Vibhakar, Rajeev
• Format: Journal Article
• Language: English
• Published: 15-04-2012
• DOI: 10.1158/1538-7445.AM2012-2483
• EISSN: 1538-7445
• ISSN: 0008-5472

Overexpression of the polycomb group gene Enhancer of Zeste 2 (EZH2) occurs in many tumors including prostate cancer, breast cancer and brain tumors such as Glioblastoma multiform and Medulloblastoma. Recent evidence suggests it may also have a role in rhabdoid tumors. Atypical teratoid rhabdoid tumor (ATRT) is a rare high-grade brain tumor with very poor survival that occurs most commonly in children. AT/RT tumors are characterized by deletion of the chromatin associated protein SMARCB1. Given the role of EZH2 in regulating epigenetic changes we chose to investigate the role of EZH2 in AT/RT. Here we show that targeted disruption of EZH2 by RNAi or pharmacologic means strongly impairs ATRT cell growth, induces apoptosis and potently sensitizes these cells to radiation. Using functional analysis of transcription factor activity we found the Cyclin D-E2F1 axis to be repressed upon EZH2 depletion in ATRT cells. Taken together our observations provide evidence that EZH2 regulates cell cycle progression by targeting the G1-S transition machinery and may be an important new therapeutic target particularly in combination with radiation in ATRT.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2483. doi:1538-7445.AM2012-2483