MDM2 Overexpression Modulates the Angiogenesis-Related Gene Expression Profile of Prostate Cancer Cells.

Thiagarajan Venkatesan,Umamaheswari Natarajan,Ali Alaseem,Khalid Alhazzani,Ruben Schwartz,Appu Rathinavelu,Aiyavu Chinnaiyan,Priya Dondapati,Thanigaivelan Kanagasabai,Saad Alobid,Sivanesan Dhandayuthapani

doi:10.3390/cells7050041

Abstract

The Murine Double Minute 2 (MDM2) amplification or overexpression has been found in many tumors with high metastatic and angiogenic ability. Our experiments were designed to explore the impact of MDM2 overexpression, specifically on the levels of angiogenesis-related genes, which can also play a major role in tumor propagation and increase its metastatic potential. In the present study, we have used the human angiogenesis RT2 profiler PCR array to compare the gene expression profile between LNCaP and LNCaP-MST (MDM2 transfected) prostate cancer cells, along with LNCaP-MST cells treated with Nutlin-3, an MDM2 specific inhibitor. As a result of the overexpression of MDM2 gene in LNCaP-MST (10.3-fold), Thrombospondin 1 (THBS1), Tumor necrosis factor alpha (TNF-α) and Matrix metallopeptidase 9 (MMP9) were also found to be significantly up-regulated while genes such as Epiregulin (EREG), Tissue inhibitor of metalloproteinases 1 (TIMP1) were down-regulated. Also, we determined the total MMP activity and MMP9 expression in LNCaP, LNCaP-MST and SJSA-1 cells. Our results indicated that MDM2 level is positively correlated with MMP activity and MMP9 secretion. Our findings offer strong supporting evidence that MDM2 can impact growth and metastatic potential of cancer cells through tilting the balance towards pro-angiogenic mechanisms.

Highlights

Most tumors contain either mutations or defects in the p53 pathway, which is considered as a major contributor to tumor development
Our studies have suggested a strong correlation between Murine Double Minute 2 (MDM2) and vascular endothelial growth factor (VEGF) in eight different cancer types, implicating a strong role for MDM2 in the regulation of angiogenesis process [12]
RT2 profiler PCR array results confirm that genes were differentially expressed 1-fold in LNCaP-MST compared to the control LNCaP cells (Table 2)

Summary

Introduction

Most tumors contain either mutations or defects in the p53 pathway, which is considered as a major contributor to tumor development. MDM2 negatively controls the protective activities of p53 through three major processes: (i) inhibition of the. Cells 2018, 7, 41; doi:10.3390/cells7050041 www.mdpi.com/journal/cells p53 transcriptional domain through direct binding, (ii) MDM2-facilitated proteasomal degradation of p53 via ubiquitination and, (iii) translocating p53 out of the nucleus to terminate its cell cycle control mechanisms. In the past few years, a group of imidazoline derivatives were developed to antagonize the MDM2-p53 interaction by binding to the N-terminal domain of MDM2 and reversing MDM2-mediated negative regulation of p53. In this context, Nutlin-3 has been studied extensively in the last fifteen years by utilizing various in vitro and in vivo models [7,8,9]. Antagonizing MDM2 protein represents an attractive approach to combat tumor growth and expansion

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Conclusion