Abstract 7070: Butyrate modulates key oncogenic pathways in oral squamous cell carcinoma: Insights from transcriptomic profiling.

Abstract Introduction: Oral squamous cell carcinoma (OSCC) is a highly aggressive epithelial malignancy that accounts for 90% of oral cancer. Due to late detection, therapeutic resistance and lacking targeted therapies the survival rate for OSCC is below 60%, therefore there is a need for identifying molecular drivers that can be therapeutically targeted. Short chain fatty acids, particularly butyrate has anti-inflammatory, immunomodulatory, and antineoplastic effects in several cancers. We have observed that butyrate treatment reduces cell viability, inhibits migration, and proliferation on OSCC. Thus, to identify the molecular mechanisms related to butyrate treatment and investigate its therapeutic potential in OSCC, we measured transcriptomic changes after butyrate treatment of OSCC. Methods: OECM-1 (OSCC cell model) were treated with 5 mM butyrate for 24 hours. RNA was extracted, quantified and sequenced on the Illumina NextSeq 550 (PE 2x75 bp). Following quality control (FastQC and Trimmomatic), high-quality reads were aligned to the human genome (GRCh38) using STAR and quantified with RSEM. Differential gene expression was analyzed using R statistical software (tximport and DESeq2 packages). Genes were considered significant if the adjusted p-value was <0.001 and had a log2 fold change >2 or <-2. Functional annotation and protein interaction analyses of significant differentially expressed genes were conducted using Metascape and STRING. Results: Butyrate treatment had a distinct transcriptomic profile than untreated cells, characterized by a significant alteration of the expression of 1,975 transcripts in OECM-1. The most upregulated transcript (11-fold increase) was NPPB, involved in cell apoptosis and anti-proliferative signaling. Conversely, CCNA2, controls both G1/S and G2/M transition phases of the cell cycle, showed a 3-fold decrease. Additionally, SYC, a modulator of epithelial cell growth, cell proliferation and differentiation, showed a 3.7-fold decrease. Enrichment analysis showed biological processes involved in oncogenesis, including cell proliferation, differentiation, apoptosis, and survival. Protein-protein interaction network identified clusters associated with cell cycle regulation, protein phosphorylation, cell death and transcription factors, with several gene hubs (≥15 connections) including CCNA2, BIRC5, KIF20A and CDCA8, known prognostic markers for cancer. Conclusions: Our results demonstrate that butyrate modulates the transcriptome of OECM-1 cells, targeting pathways involved in oncogenic processes such as cell cycle, proliferation signaling, genetic regulators and apoptosis, consistent with our cellular results. NPPB is a novel marker for gastric cancer, showing butyrate's capacity to regulate antiproliferative pathways. These findings support butyrate's potential as a microbiome-derived therapeutic for OSCC. Citation Format: Oscar A. Loperena Gonzalez, Ariana S. García- López, Liah M. Román-Calderón, Gabriel Borges Vélez, Esther Peterson Peguero, Josué Pérez Santiago. Butyrate modulates key oncogenic pathways in oral squamous cell carcinoma: Insights from transcriptomic profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 7070.