MT1JP: A Pivotal Tumor-Suppressing LncRNA and its Role in Cancer Progression and Therapeutic Potential.

Metallothionein 1J pseudogene (MT1JP) is a long non-coding RNA (lncRNA) that functions as a tumor suppressor in various malignancies. Reduced MT1JP expression is associated with increased tumor proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and treatment resistance in nine cancers, such as gastric cancer, intrahepatic cholangiocarcinoma, hepatocellular carcinoma, and breast cancer. Mechanistically, MT1JP acts as a competitive endogenous RNA (ceRNA) to regulate oncogenic microRNAs (miRNAs), including miR-92a-3p, miR-214-3p, and miR-24-3p. This regulation restores tumor suppressor genes, such as FBXW7, RUNX3, and PTEN, thereby disrupting oncogenic pathways, including PI3K/AKT, Wnt/β- catenin, and p53, promoting apoptosis, and inhibiting tumor progression. Clinically, MT1JP expression correlates with tumor grade, differentiation, TNM stage, lymph node metastasis, and patient prognosis, suggesting its potential as a diagnostic and prognostic biomarker. Furthermore, its therapeutic potential in RNA-based treatments has attracted significant attention. Despite these findings, questions remain regarding its role in epigenetic regulation, transcriptional control, and RNA delivery. This review explores the molecular mechanisms underlying MT1JP, highlighting its clinical relevance and potential as a therapeutic target. Future research should focus on elucidating its role in epigenetic regulation, overcoming challenges in therapeutic delivery, and validating its utility as a biomarker for different cancers. MT1JP holds promise for advancing precision oncology by providing innovative approaches for cancer diagnosis and treatment.