(-) - Epicatechin regulates LOC107986454 by targeting the miR-143-3p/EZH2 axis to enhance the radiosensitivity of non-small cell lung cancer.

Background and objective: Non-small cell lung cancer (NSCLC) is a pernicious tumor with high incidence and mortality rates. The incidence rate of NSCLC increases with age and poses a serious danger to human health. The aim of this study was to determine the mechanism by which (-)-epicatechin (EC) alleviates NSCLC.

Methods: Twenty-four pairs of NSCLC tissues and cancer-adjacent tissues were collected, and A549 and H460 radiotherapy-resistant strains were generated by repeatedly irradiating A549 and H460 cells with dose-gradient X-rays. Radiotherapy-resistant H460 cells were successfully injected subcutaneously into the left dorsal side of nude mice at a dose of 1 × 10⁵ to establish an NSCLC animal model. The levels of interrelated genes and proteins were detected by RT‒qPCR and Western blotting, and cell proliferation and apoptosis were evaluated by CCK‒8 assay, Transwell assay, flow cytometry, and TUNEL staining.

Results: LOC107986454 was highly expressed in NSCLC patients, while miR-143-3p was expressed at low levels and was negatively correlated with LOC107986454. Functionally, EC promoted autophagy and apoptosis induced by radiotherapy, restrained cell proliferation and migration, and ultimately enhanced the radiosensitivity of NSCLC cells. A downstream mechanistic study showed that EC facilitated miR-143-3p expression by inhibiting LOC107986454 and then restraining the expression of EZH2, which ultimately facilitated autophagy and apoptosis in cancer cells, inhibited proliferation and migration, and enhanced the radiosensitivity of NSCLC cells.

Conclusion: EC can enhance the radiosensitivity of NSCLC cells by regulating the LOC107986454/miR-143-3p/EZH2 axis.