Taurine up-regulated 1: A dual regulator in immune cell-mediated pathogenesis of human diseases

Taurine up-regulated 1 (TUG1) is a long non-coding RNA (lncRNA) that plays a significant role in the pathogenesis of both cancer and non-cancer diseases. Recent studies have revealed its involvement in regulating the development of various diseases by modulating the activity of the body's immune cells. In non-cancer diseases, TUG1 primarily influences disease progression through the competing endogenous RNA (ceRNA) network, promoting the expression of pro-inflammatory cytokines via pathways such as the NF-κB inflammatory signaling pathway. Most research indicates that TUG1 exerts a positive regulatory effect on immune cells, including Th2 cells, M1 macrophages, and microglia. In cancer, TUG1 regulates disease progression predominantly through the ceRNA network and by modulating the activity of specific transcription factors. It fosters tumor development by promoting the establishment of immune tolerance within the tumor microenvironment. This immune tolerance is associated with TUG1's regulation of immune checkpoint molecules, which enhances the infiltration of pro-tumor immune cells (e.g., regulatory T cells, M2 macrophages, neutrophils, and dendritic cells) while suppressing the infiltration of anti-tumor immune cells, including CD8⁺ T cells, NK cells, and M1 macrophages. In this study, we systematically evaluate the impact of abnormal TUG1 expression across various diseases, focusing on its mechanisms of action in regulating immune cell infiltration and disease progression in both cancer and non-cancer contexts. We also discuss potential targets for future research related to TUG1's role in these pathogenic processes.