Temporal Transcriptomic Profiling of NMBA-Induced Rat Esophageal Squamous Carcinogenesis Identifies Early Inflammatory Activation and Late NRF2-Associated Oxidative-Stress Remodeling.

Abstract

Temporal molecular events during early esophageal squamous carcinogenesis remain incompletely defined, in part because human precursor tissues are difficult to obtain sequentially. We used the N-nitrosomethylbenzylamine (NMBA)-induced rat model to characterize stage-associated transcriptional programs during esophageal squamous carcinogenesis. Vehicle-control reference esophageal tissues and NMBA-treated esophageal tissues, collected at weeks 6 and 29, were profiled using Affymetrix Rat Genome 230 2.0 arrays, followed by pathway analysis and qRT-PCR validation of selected genes. Relative to vehicle-control reference tissues, 173 genes were differentially expressed at week 6, whereas 1628 genes were differentially expressed at week 29, indicating marked expansion of transcriptional dysregulation during carcinogenic progression. Sixteen genes were differentially expressed only at week 6, while 157 genes were altered at both time points. Pathway analysis suggested that inflammatory and immunologic processes were prominent during the early response to NMBA exposure, whereas late-stage carcinogenesis was characterized by NRF2-associated oxidative-stress response and dysregulation of multiple glutathione S-transferase family members. A subset of progression-associated genes, including Defb4, Gsta2, Sbsn, Spink5, Plcd4, Hbb, and Hba-a2, showed increasing dysregulation from week 6 to week 29. These findings define temporally distinct molecular programs in NMBA-induced esophageal squamous carcinogenesis and provide a framework for prioritizing candidate pathways and genes relevant to esophageal cancer prevention, early detection, and progression biology.