VCOM Louisiana Research Day Program Book 2024

Biomedical Research: Section 2

Md. Towhidul Islam Tarun, MS 1 ; Hassan Y. Ebrahim, PhD 1,2 ; Zakaria Abd Elmageed, PhD 2 ; Khalid A. El Sayed, PhD 1 * 1 University of Louisiana Monroe, College of Pharmacy; 2 VCOM-Louisiana 22 (-)-S-OLEOCANTHAL ATTENUATES THE PROGRESSION AND RECURRENCE OF NEUROENDOCRINE PROSTATE CANCER THROUGH DOWNREGULATION OF THE PROTEIN LYSINE METHYLTRANSFERASE SMYD2

Background: Prostate cancer (PCa) remains the most common malignancy and the second leading cause of death among the male population in United States. Despite the significant advances in the treatment modalities at early disease stages, most patients inevitably progress to advanced and metastatic PCa where therapeutic options are very limited and subeffective. Androgen deprivation therapy (ADT) combined with second-generation androgen receptor (AR) signaling inhibitors such as abiraterone acetate and enzalutamide are standard first-line alternatives for metastatic PCa. The extensive clinical implementation of these AR targeting drugs promoted phenotypic differentiation of AR-expressing PCa to AR-negative, very aggressive, and poorly differentiated small-cell neuroendocrine carcinoma known as neuroendocrine prostate cancer (NEPC). The platinum-based chemotherapy is the only approved therapeutic option,which achieves modest outcomes. Protein methylation is one of the most important posttranslational modificationsthat has been linked to oncogenesis, and aggressive cancers, including PCa. The SET and MYND-containing protein 2 (SMYD2) is an N-lysine methyltransferase that methylates both histone and non-histone protein substrates, including H3/4, p53, EZH2, STAT-3, PTEN and NF k B. These diverse oncogenic signaling substrates broaden the function of SMYD2in a variety of cancers, including PCa.

Objective: This study aims at assessing the activity of the extra-virgin olive oil (EVOO) monophenolic secoiridoid (-)-S-oleocanthal (OC) as a novel intervention for NEPC progression and recurrence via modulation of SMYD2. Methods: The study utilized the MTT assay to evaluate OC’s impact on NEPC cell lines, focusing on the modulation of SMYD2 expression. Successful CRISPR/Cas9 knockout (KO) plasmid transfection was confirmed via Western blotting, comparing the de novo NEPC wild-type NCI-H660 cells with NCI H660-KO cells. In the invitro phase, OC treatments were administered at varying doses to assess their influence on SMYD2 expression within NEPC cells over a 48-hour culture period. The study also employed athymic Foxn1nu nude male mice to generate a denovo NEPC progression and recurrence model, xenografting with NCI-H660 cells, which were bioluminescent-tagged with firefly luciferase (NCI H660-Luc) and subcutaneously implanted. Additionally, NSG mice xenografted with LuCaP 93 neuroendocrine prostate patient-derived xenografts (PDX) were utilized to represent the treatment-induced NEPC. Results: OC significantly attenuated the in vitro proliferation of the NEPC cells in a dose-dependent manner. The NCI-H660 cells treated with different concentrations of OC showed a significant

downregulation of SMYD2 expression level and its downstream signaling pathways in a dose dependent manner. Daily OC oral treatments (10 mg/kg) dispersed in dephenolated EVOO (dpEVOO) matrix significantly suppressed the in vivo progression of the NEPC NCI H660-Luc cell tumors. Notably, OC potently reduced the tumor volume and weight (72.1 % and 83.7 %, respectively) in treated animals compared to dpEVOO placebo group at the end of the primary progression phase. Afterwards, tumors were surgically excised, and animals continued to receive daily OC 10 mg/kg and dpEVOO treatments over two additional months. No locoregional tumor recurrences were detected in OC-treated animals, while 60% of the placebo-treated group mice showed palpable and positive bioluminescence locoregional recurrent tumors. Moreover, daily oral OC 10 mg/kg treatments for 49 days potently suppressed the progression of the NEPC LuCaP 93 PDX transplanted in NSG mice (94% suppression) versus the placebo dephenolized EVOO control mice. Conclusions: Collectively, this study results support the promotion of the EVOO-derived OC as a novel nutraceutical intervention for the control of aggressive NEPC.

35 2024 Via Research Recognition Day