Abstract 5764: The emerging protective role of silymarin in stress associated hepatocellular carcinoma

Abstract Background: Texas is projected to have the second-highest liver cancer-related deaths in the nation, with Hispanic populations experiencing the highest mortality rates. In the South Texas Rio Grande Valley (RGV), where ∼90% of the population is Latino/Hispanic, socioeconomic disparities, poverty, obesity, diabetes, and low-income levels contribute to heightened stress prevalence. Stress accelerates cancer progression by impairing immune responses, inducing inflammation, and activating the hypothalamic-pituitary-adrenal (HPA) axis, releasing cortisol and leptin, key drivers of oncogenesis. Silymarin, a polyphenolic antioxidant from milk thistle seeds, is a known hepatoprotective agent with benefits in stress-related hypertension, atherosclerosis, and cardiotoxicity. However, its role in stress-induced HCC remains unexplored. This study investigates silymarin's effects on stress-induced proteins in HCC. Methods: HCC cell lines were treated with cortisol and leptin to simulate acute and chronic stress conditions. Gene expression was analyzed via reverse transcription-polymerase chain reaction (RT-PCR), and overexpression models were established using lentiviral vectors. Proteins and pathways associated with stress were identified through liquid chromatography-mass spectrometry (LC-MS). Identified genes were validated via RT-PCR and western blot analysis in stress-treated and silymarin-treated cells. Results: LC-MS analysis identified over 3000 proteins, with 6.3% categorized as stress-response proteins. Eleven key stress-associated proteins, including IPO7, SCFD1, TIPRL, SCL25, SERPINB6, TRMT2, and HSP90B1, were validated in leptin- and cortisol-treated SK-Hep1 cells and Malat1 overexpression cell lines. The Cancer Genome Atlas (TCGA) database analysis confirmed these findings in HCC patient cohorts. Notably, silymarin significantly reduced stress-response gene expression in treated SK-Hep1 cells while sparing untreated parental cells. Further pathway analyses and validation in knockdown models are ongoing to elucidate mechanisms underlying these effects. Conclusion: Silymarin effectively downregulated cortisol- and leptin-induced stress-response proteins in SK-Hep1 cells, highlighting its therapeutic potential in stress-associated HCC. These findings underscore silymarin's role in targeting novel molecular pathways, offering promising strategies to address HCC disparities in underserved populations in the RGV. This research aims to improve outcomes and reduce mortality among high-risk groups, addressing a critical healthcare challenge in Texas. Citation Format: Mohammad S. Hussain, Yamile Abuchard Anaya, Ricardo Pequeno Bracho, Amayrani Sanchez, Sophia Leslie, Kyle Doxtater, Subhash C. Chauhan, Tamer Oraby, Elias George, Manish K. Tripathi. The emerging protective role of silymarin in stress associated hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5764.