Raddeanin A Suppresses Intracellular 5Methylcytosine (5mC) DNA Modification Engaged the Metastasis of Hepatocellular Carcinoma (HCC).

Ethnopharmacological relevance: The Anemonoides Raddeana (Rege) Holubhe is commonly employed in clinical practice as a traditional Chinese medicine for the treatment of conditions such as rheumatism and limb numbness. Raddeanin A (RA), an active compound derived from this Traditional Chinese Medicine (TCM), demonstrates specific anticancer properties against many tumorigeneses. However, the molecular mechanism underlying its effects on hepatocellular carcinoma (HCC) remains unexplored.

Aim of the study: The aim of this study is to investigate the inhibitory effects of RA in human HCC stimulated cells and its impact on DNA methylation in tumor cells, as well as to elucidate the molecular mechanisms underlying RA's anti-tumor activity.

Materials and methods: The inhibitory effects of RA on QGY-7703 and HepG2 cells were evaluated. The IC₅₀ values were determined by employing non-linear sigmoidal curve fitting to analyze the normalized response. The impact of RA was investigated in cells overexpressing DNMT3A and DNMT3B. The effects of RA on cell cycle progression and apoptosis were assessed. Furthermore, the influence of RA on cellular methylation was determined, along with its effects on the expression levels of DNMT3A, DNMT3B, Bcl-2, Bax, and Caspase-3.

Results: The findings demonstrate that RA induces cell cycle arrest at the G0/G1 phase and promotes apoptosis in hepatocellular carcinoma cells. Furthermore, RA effectively inhibits the invasion and migration of human HCC stimulated cells. The expression of DNMT3A and DNMT3B is downregulated by RA, effectively suppressing the intracellular ⁵mC DNA modification level. Moreover, the overexpression of these enzymes in RA-treated human HCC stimulated cells significantly impacts the overall ⁵mC level and hinders tumor metastasis by restricting migration and invasion.

Conclusion: The RA compound acts as an antagonist against HCC by reducing intracellular DNA ⁵mC levels through mechanisms mediated by methyltransferase. Moreover, RA demonstrates the capacity to induce apoptosis in tumor cells, thereby exerting its anti-tumor effects. The findings of this study provide valuable insights for enhancing the pharmacodynamic efficacy of RA in HCC treatment.