Long non-coding RNA TUSC7 suppressed colorectal cancer progression via regulation of miR-23b/PDE7A Axis

Purpose: Despite advances in our understanding of the roles of the long noncoding RNA (lncRNA) tumor suppressor candidate 7 (TUSC7) in cancer biology, which has been identified to act as a tumor suppressor by regulating cell proliferation, apoptosis, migration, invasion, cell cycle and tumor growth, its function in colorectal cancer remains unknown. Methods: The expression levels of TUSC7 in colorectal cancer tissues and cell lines were determined, and the biological functions of TUSC7 to cancer progression in colorectal cancer were investigated via correlation analysis of clinical samples, cell viability assay, transwell assay and apoptosis analysis. Further, the molecular regulatory mechanisms of TUSC7 were demonstrated by luciferase reporter assay and western blotting. Results: We observed that the expression of TUSC7 was markedly decreased in colorectal cancer cell lines. Moreover, the lower expression of TUSC7 was correlated with advanced clinical grades and poorer survival and may be an independent risk factor for colorectal cancer. Moreover, the expression of TUSC7 inhibited cell proliferation, invasion and epithelial-to-mesenchymal transition (EMT), while it facilitated apoptosis through competitively binding miR-23b. We also found that TUSC7 decreased the expression of phosphodiesterase 7A (PDE7A), a downstream target of miR-23b, through the TUSC7/miR-23b/PDE7A axis. Conclusion: We demonstrated the expression of TUSC7 suppressed colorectal cancer progression through the TUSC7/miR-23b/PDE7A axis, suggesting that TUSC is a potential target for therapeutic intervention in colorectal cancer