Abstract 1102: Amentoflavone enhances regorafenib-induced apoptosis and -inhibited invasion via inactivating STAT3/NF-ΚB signaling pathway in Hepatocellular carcinoma

Abstract

Abstract Hepatocellular carcinoma (HCC) is an aggressive tumor and ranks as the third leading cause of cancer-related deaths worldwide. Amentoflavone, a biflavonoid compound, possesses antiviral, angiogenesis-inhibitory, and anticancer properties. Prior studies have illustrated that amentoflavone effectively restrains tumor growth and promotes apoptosis in various cancers, including brain cancer and osteosarcoma. Regorafenib, a small molecule inhibitor of multi-kinases, can inhibit angiogenesis, tumor growth, and anti-tumor metastasis. While regorafenib is a targeted drug approved for the treatment of metastatic colorectal cancer and has also been approved for use in HCC, its effectiveness in HCC is limited. Consequently, our goal is to investigate whether amentoflavone may enhance the sensitivity of regorafenib in treating HCC and explore the underlying mechanisms. In our study, through the combined treatment and combination index analysis, we proved that the combination of regorafenib and amentoflavone may induce cytotoxicity more effectively compared to monotherapy, as assessed by the MTT assay in Huh7 and HepG2 cells. The invasion and migration assays also demonstrated a superior inhibitory effect in the combination group. Additionally, apoptosis markers such as "cleaved caspase-3, -8, -9, Fas and FasL" assayed by flow cytometry, confirm that the combination treatment may induce the extrinsic/intrinsic apoptosis pathway in HCC. In our Western blotting analysis, we observed that the phosphorylation of STAT3 and NF-κB proteins was effectively suppressed by the combination of regorafenib and amentoflavone in Huh7 and HepG2 cells, respectively. Furthermore, our in vivo study confirmed a superior tumor inhibition rate and control rate with the combination of regorafenib and amentoflavone. Importantly, no signs of general toxicity were observed in any of the treatment groups, as evidenced by body weight monitoring and Hematoxylin and Eosin stain (H&E) pathology evaluation. We believe that the combined treatment of these two drugs effectively triggers cell death and suppresses metastatic patterns through the inactivation of the STAT3/NF-κB signaling pathway. These results suggest that amentoflavone has the potential to serve as an adjuvant that sensitizes regorafenib for the treatment of HCC without causing any side effects. Citation Format: Yan ting Tsai, Ying-Tzu Chen, Fei-Ting Hsu, Jai-Jen Tsai, Yu-Chiang Liu. Amentoflavone enhances regorafenib-induced apoptosis and -inhibited invasion via inactivating STAT3/NF-ΚB signaling pathway in Hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1102.