Abstract 2365: Analysis of angiogenesis pathway-related gene expression impacted by MDM2 using PCR array

Abstract

Abstract The Murine Double Minute 2 (MDM2) gene encodes an oncogenic MDM2 protein, which is a negative regulator of the p53 tumor suppressor. MDM2 amplification or over expression is found in many tumors that eventually lead to the inactivation of the cell cycle control and loss of pro-apoptotic functions that are typically exerted by wild type p53. Many of the oncogenic effects of MDM2 are resulting from the inactivation of p53 through direct binding or degradation of p53 following E3 ligase mediated ubiquitination. However, our recent findings have indicated that MDM2 over expression can also promote tumor angiogenesis through p53 independent pathways and thereby enhance the metastatic potential of cancer cells. In this respect increasing the levels of pro-angiogenic factors such as VEGF has been confirmed as one of the mechanisms regulated by MDM2. However, the actual cluster of genes or pathways regulated by MDM2 leading to such increase in the metastatic potentials of cancer cells have not been clearly identified. Therefore, the main purpose of our study was to understand the impact of MDM2 over expression on the levels of angiogenesis related genes that can also increase growth rate and metastatic potential. Hence, for our study we used the Human Angiogenesis PCR Array to compare the gene expression profile of LNCaP (prostate cancer cells) and LNCaP-MST (MDM2 transfected prostate cancer) cells. The MST cells expressed at least 10 fold increase in the levels of MDM2 after transfection. As a result of the elevated levels of MDM2 in LNCaP-MST cells the expression of genes such as THBS1 (125 fold), TNF-α (14 fold), MMP-9 (1.4 fold) were found to be significantly up-regulated compared to the MDM2 non-transfected cells. Cluster analysis further confirmed that these gene expression profiles are positively correlated with the pro-angiogenic potential of the LNCaP-MST cells compared to the non-transfected cells. In addition, the levels of EREG, TIMP1 and CXCL3 were down regulated significantly that favors the suppression of anti-angiogenic mechanisms. Our results offer a conclusive evidence that MDM2 can impact the cancer growth and metastatic potential of cancer cells by shifting the balance towards pro-angiogenic mechanisms (The financial support from the Royal Dames of Cancer Research Inc., Ft. Lauderdale, Florida is gratefully acknowledged). Citation Format: Thiagarajan Venkatesan, Corine Stinson, Sivanesan Dhandayuthapani, Appu Rathinavelu. Analysis of angiogenesis pathway-related gene expression impacted by MDM2 using PCR array. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2365. doi:10.1158/1538-7445.AM2014-2365