Louisiana Research Day Program Book 2025

Biomedical Research: Section 2

Biomedical Research: Section 2

Mohammad Nurul Amin, M.Pharm 1 ; Md Saqline Mostaq, MSc 1 ;Lin Kang, PhD 1,2 ; Yong-Yu Liu, MD, PhD 1 1 School of Basic Pharmaceutical and Toxicological Sciences, University of Louisiana at Monroe, USA; 2 Department of Biomedical Affairs and Research, VCOM-Louisiana, Monroe, USA 23 M6A MODIFICATION OF TP53 R273H IN BREAST CANCER CELLS DEACTIVATES NATURAL KILLER CELLS

Nehal A. Ahmed, MSc; Abu Bakar Siddique, PhD; Judy King, PhD; Khalid A. El Sayed, PhD School of Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 1800 Bienville Dr, Monroe, LA; Department of Translational Pathobiology, LSU Health, 1501 Kings Highway, Shreveport, LA 24 WHICH OLIVE OIL CULTIVAR IS THE BEST FOR USE TO CONTROL INVASIVE BREAST CARCINOMA?

Background: Missense mutation of tumor suppressor gene TP53 expresses oncogenic proteins and promotes tumor progression. However, the mechanisms by which p53 mutant proteins mask cancer cells from anticancer immunity remain poorly understood. TP53 mutations, particularly R273H, are associated with poor outcomes in triple-negative breast cancer and impaired natural killer (NK) cell activity. Previous studies indicate murine p53 missense mutant G242A suppress the activation of host natural killer (NK) cells in protection of breast cancer cells from immune destruction. The objective of this study is to examine the role of N6-methyladenosine (m6A) modification at the mutant TP53 codon in suppressing NK cell-based immunity. Using human MDA MB-468 breast cancer cells (p53 R273H) and NK-92-MI cells, we demonstrate that p53 R273H deactivates NK cells, reducing interferon- γ (IFN- γ ) production compared to wild-type p53 MCF-7 cells or noncancerous MCF-10A cells. Further proteomics and validation experiments revealed that YTHDF-2 is a key m6A reader involved in modulating the effects of m6A at the R273 mutant codon on expression of p53 mutant and deactivation of NK cells. These

findings highlight the potential of targeting m6A modification as a therapeutic strategy to enhance NK cell-based antitumor immunity in breast cancer.

Background: Breast Cancer (BC) is the most common diagnosed malignancy among females and the second leading cause of cancer-related mortalities in women. BC is a heterogeneous disease, that is classified into 4 subtypes: luminal A (ER-and/or PR positive/HER2-negative/low Ki-67), luminal B (ER-positive/HER2-positive/high Ki-67), non luminal HER2-positive (ER and PR absent/ HER2 overexpression), and triple negative (ER and PR absent/HER2-negative, TNBC). Epidemiological studies indicate reduced BC incidence in Mediterranean population due to daily consumption of Mediterranean diets rich in extra-virgin olive oil (EVOO). EVOO exclusive phenolics are widely known for their positive outcomes on multiple types of cancers, including BC. Example of EVOO minor phenolics are oleocanthal (OC), hydroxyoleocanthal (HOC), ligstroside aglycone (LA), tyrosol, hydroxytyrosl, and others. The current study investigates the anti-BC effect of individual and combined EVOO phenolics on the BC progression and motility. Screening of a small library of EVOO phenolics (9 compounds) at a single dose of 10 µM on cell viability of the BC cell lines ZR-75-1 (luminal A) and MDA-MB-231 (TNBC)

showed most favorable results for OC and LA. Moreover, the cell migratory inhibition screening of EVOO phenolics identified the topmost active 4 out of 9 phenolics including OC, LA, and the lignans actoxypinoresinol, and pinoresinol. Combination studies of different olive phenolics showed that combined OC and LA had the best synergistic inhibitory effect on the MDA MB-231 cell migration. Animal studies using the ZR-75-1 cells orthotopic xenografting model in nude mice demonstrated combined daily oral 5 mg/kg of each of OC and LA significantly suppressed breast luminal A tumor progression compared to vehicle control and the individual administration of each one of them. Metastasis colonization animal study model in nude mice subjected to tail vein injection of MDA-MB-231 TNBC cells also revealed effective synergy of combined use of daily oral 5 mg/kg of each of OC and LA versus their individual use and vehicle control. Histopathological examination of combined OC+LA treated animal lung tissues indicated significantly reduced metastatic focci versus individual use of each of OC and LA as compared to vehicle control group. Western blotting investigation of collected ZR-75-1 cells animal tumors showed significant suppression

of the previously validated molecular target SET and MYND domain-containing protein 2 (SMYD2) and total c-MET receptor tyrosine kinase. SMYD2, a lysine methyltransferase and c-MET, the hepatocyte growth factor ligand, are well known to activate several downstream signaling pathways by protein-protein interactions with oncogenic proteins. Thus, an EVOO cultivar rich in OC with optimal LA content can be very effective to control invasive BC progression and metastasis. OC-LA-rich EVOO can be developed as a potential nutraceutical for use by the BC patients and survivors.

Keywords: BC, EVOO, Ligstoside aglycone, c-MET, Metastasis, Oleocanthal, SMYD2.

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2025 Research Recognition Day