Chelerythrine Inhibits TGF-β-Induced Epithelial–Mesenchymal Transition in A549 Cells via RRM2

<b>Background:</b> The mechanisms underlying the metastasis of non-small-cell lung cancer (NSCLC) have long been a focal point of medical research. The anti-tumor effects of chelerythrine (CHE) have been confirmed; however, its ability to inhibit tumor metastasis and the underlying mechanisms remain unknown. The aim of this study was to investigate the inhibitory effects and molecular mechanisms of CHE on transforming growth factor-beta (TGF-β)-induced epithelial-mesenchymal transition (EMT). <b>Methods</b>: Wound healing and Transwell assays were employed to evaluate TGF-β-induced migration in A549 cells and the inhibitory effects of CHE. Ribonucleotide reductase subunit M2 (RRM2) expression levels were detected via Western blot and immunofluorescence staining. Western blot and RT-qPCR were used to examine the expression levels of EMT-related markers. Animal experiments were conducted to analyze the role of RRM2 in the CHE inhibition of TGF-β-induced lung cancer metastasis. <b>Results</b>: This study found that TGF-β treatment enhanced the metastasis of A549 cells, while CHE inhibited the expression of TGF-β-induced EMT-related transcription factors by RRM2, thereby suppressing tumor cell migration (<i>p</i> < 0.05). Furthermore, the oral administration of CHE inhibited the metastasis of A549 cells to the lungs from the tail vein in mice, consistent with in vitro findings. Despite the high doses of CHE used, there was no evidence of toxicity. <b>Conclusions</b>: Our data reveal the mechanism of the anti-metastatic effects of CHE on TGF-β-induced EMT and indicate that CHE can be used as an effective anti-tumor treatment.