Therapeutic Potential of CUDC-907 (Fimepinostat) for Hepatocarcinoma Treatment Revealed by Tumor Spheroids-based Drug Screening

Abstract

Background: Cancer is the second leading cause of death globally. However, most of the new anti-cancer agents screened by traditional drug screening methods fail in the clinic because of lack of efficacy. One of the reasons for this dilemma is that the two-dimensional (2D) culture cancer cell lines could not represent the in vivo cancer cells well. Fortunately, the development of a three-dimensional (3D) culture technique helps in this problem. Methods: The high-throughput spheroid culture plate was fabricated by using 3D print technique and agarose. 4 hepatocarcinoma (HCC) cell lines were 3D cultured to screen 19 small molecular agents based on the spheroid culture plate. 3D cultured primary HCC cells and tumor-bearing mice model were established to verify the candidate anti-hepatocarcinoma agent. Cell function experiments and western blotting were conducted to explore the anti-hepatocarcinoma mechanism of the candidate agent. Results: Based on the previous study, we established an in vitro 3D drug screening method by using our invented spheroid culture device and found that CUDC-907 can serve as a potent anti-hepatocarcinoma agent. The study data show that CUDC-907 (fimepinostat), a novel dual acting inhibitor of phosphoinositide 3-kinase (PI3K) and histone deacetylase (HDAC), has potent inhibitory effects on HCC cell lines and primary HCC cells in vitro, Animal studies have shown that CUDC-907 can also suppress HCC cells in vivo. Furthermore, we investigated the antitumor mechanism of CUDC-907 in HCC cells. We found that it inhibits the PI3K/AKT/mTOR pathway and downregulates the expression of c-Myc, leading to the suppression of HCC cells. Conclusion: Our results suggest that CUDC-907 can be a candidate anti-HCC drug, and the 3D in vitro drug screening method based on our novel spheroid culture device is promising for drug screening.