Abstract 5682: Micro RNA level changes in prostate cancer cells treated with MDMX and MDM2 inhibitors

Abstract INTRODUCTION: Prostate Cancer (PCa) is the most common non-cutaneous cancer and the second leading cause of cancer death among men in the United States. Most of the PCa cases are diagnosed in men between the ages of 65-74. Due to the recent push for frequent prostate screenings, these cancers are being detected early and treated much faster, leading to a 5-year survival of a localized or regional PCa to 99%. However, the 5-year survival of PCa with distant metastasis is significantly reduced to 32%, especially with involvement of osteoblastic bone lesions, lung lesions, and brain lesions. Therefore, there is a clinical need to identify prognostic markers and new targets for developing therapies and effectively treating advanced PCa. Previous studies have shown that levels of MDMX and MDM2, oncogenic inhibitors of p53 tumor suppressor protein, are significantly elevated in PCa cells. Inhibition of MDM2 and MDMX using specific inhibitors has been shown to elevate the levels of p21, p27, and p53 in LNCaP (Lymph Node Carcinoma of the Prostate) cells leading to cell death. Recent studies have demonstrated that micro RNAs (miRNAs) play an important role in supporting the tumor suppressor function of p53 through regulating the balance between p53 and MDM2. In this regard, several miRNAs were found to be significantly altered to modulate the level and intracellular mechanisms of p53 and MDM2 in various cancers. OBJECTIVES: To determine the relative levels of miRNA31, miRNA-34a and miRNA-128 in LNCaP cells that were treated with NSC-207895 (MDMX inhibitor), SJ-172550 (MDMX inhibitor), and RG-7388 (MDM2 inhibitor). METHODS: LNCaP cells were treated with NSC-207895 (20 uM), SJ-172550 (20 uM) or RG-7388 (2 uM) for 24 hrs. After completing the treatments, the miRNAs were extracted from the LNCaP cells using the miRNeasy Tissue/Cells Advanced Kit from Qiagen. We analyzed the levels of miRNA-31, miRNA-34a, and miRNA-128 in the treated samples using qRT-PCR analysis method and compared the levels to the control. During the qRT-PCR analysis the cDNA was amplified using Meridian Biosciences qPCR Master Mix and specific primers for miRNAs from Origene were used according to the manufacturer's protocol. RESULTS: Our experimental results indicate that inhibition of MDMX using NSC-207895 and SJ-172550 can elevate the levels of p21, p27, and p53 leading to cell death. Determination of cell death markers in the past revealed induction of necroptosis following drug treatments. Our current results indicate measurable changes in the levels of miRNA-31 and miRNA-34a following inhibition of MDMX using SJ-172550. We are in the process of determining the possible link between the changes in the levels of miRNAs and cell death. ACKNOWLEDGEMENT: This research was supported by the Royal Dames of Cancer Research, Ft. Lauderdale, Florida. Citation Format: Rojin Fatirkhorani, Ahmed Saleh Alsarrani, Shyam Sundar Jaganathan, Umamaheswari Natarajan, Appu Rathinavelu. Micro RNA level changes in prostate cancer cells treated with MDMX and MDM2 inhibitors abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 5682.