Dimethyl fumarate (DMF) inhibits migration and proliferation of hepatocellular carcinoma (HCC)

Introduction:

Dimethyl fumarate (DMF) is used to treat psoriasis (Fumaderm®) and multiple sclerosis (Tecfidera®). Recently, we have shown that DMF treatment leads to induction of cell death in NF-KB-dependent tumors. Cell death is induced by DMF-mediated formation of the ripoptosome which induces apoptosis and/or necreptosis. A mouse tumor model revealed that DMF application led to inhibition of metastasis formation, which was NF-KB-independent. Thus, we analyzed NF-KB-independent tumor cell lines (e.g. from colon, pancreas) in which DMF led to reduced migration and invasion. Recently, we analyzed whether DMF application leads to an inhibition of migration in NF-KB-independent HCC cell lines.

Methods:

Human HCC cell lines HepG2, Huh7 and Hep3B were treated with DMF (25µM up to 100µM) for up to 72h. The cellular ATP content was measured using a luminescence based assay. To test the effects on migration a scratch assay with HCC cell lines was performed. DMF-treated cells were co-incubated with zVAD (50µM) a caspase inhibitor to prevent induction of apoptosis. Cell migration was analyzed by microscopy. In addition, cell proliferation of HepG2 cells was determined. HepG2 were stained with Cytopainter Cell Proliferation Staining Reagent. The dye is divided between mother and daughter cell after each cell division. The proliferation of HepG2 was monitored after 24h, to 96h by FACS analysis.

Results:

DMF application resulted in a dose-dependent reduction of ATP-concentration in all cell lines. The strongest effects were observed upon 72h treatment at a concentration of 100µM DMF. Additionally, DMF application resulted in a dose dependent inhibition of migration of Huh7 and Hep3B cells. Migration of Hep3B cells was inhibited at a concentration of 25µM DMF. A concentration of 100µM DMF led to a complete block of migration in Hep3B cells. Migration inhibition of Huh7 cells was less effective. In addition, we analyzed proliferation of HepG2 cells which was inhibited time- and dose-dependent by DMF application.

Conclusion:

Solid tumors (e.g. HCC) display a rather high mortality rate due to formation of metastasis. Here, we could show that DMF is capable to inhibit migration and proliferation in HCC cell lines. To identify the exact molecular mechanism is a challenging task for the future. Compared to anti-cancer drugs DMF shows less side effects, DMF is clinical approved and could be used as a basis to develop novel treatment options against metastasis formation.