Withaferin A, a natural thioredoxin reductase 1 (TrxR1) inhibitor, synergistically enhances the antitumor efficacy of sorafenib through ROS-mediated ER stress and DNA damage in hepatocellular carcinoma cells.

BACKGROUND: Sorafenib (Sora), a multi-target tyrosine kinase inhibitor, is widely recognized as a standard chemotherapy treatment for advanced hepatocellular carcinoma (HCC). However, drug resistance mechanisms hinder its anticancer efficacy. Derived from Withania somnifera, Withaferin A (WA) exhibits remarkable anti-tumor properties as a natural bioactive compound. This study aimed to examine the mechanisms that underlie the impacts of Sora and WA co-treatment on HCC. METHODS: Cell proliferation was evaluated through colony formation and MTT assays. Flow cytometry was employed to determine cellular apoptosis and reactive oxygen species (ROS) levels. The evaluation of apoptosis-related protein levels, DNA damage, and endoplasmic reticulum stress was conducte utilizing IHC staining and western blotting. Moreover, the caspase inhibitor Z-VAD-FMK, ATF4 siRNA, ROS scavenger N-acetyl cysteine (NAC), and TrxR1 shRNA were used to elucidate the underlying signaling pathways. To validate the antitumor effects of Sora/WA co-treatment, in vivo experiments were ultimately executed using Huh7 xenografts. RESULTS: Sora/WA co-treatment demonstrated significant synergistic antitumor impacts both in vivo and in vitro. Mechanistically, the enhanced antitumor impact of Sora by WA was achieved through the inhibition of TrxR1 activity, resulting in ROS accumulation. Moreover, ROS generation induced the activation of DNA damage and endoplasmic reticulum (ER) stress pathways, eventually triggering cellular apoptosis. Pre-treatment with the antioxidant NAC significantly inhibited ROS generation, ER stress, DNA damage, and apoptosis induced by Sora/WA co-treatment. Additionally, the inhibition of ATF4 by small interfering RNA (siRNA) attenuated Sora/WA co-treatment-induced apoptosis. In vivo, Sora/WA co-treatment significantly suppressed tumor growth in HCC xenograft models and decreased TrxR1 activity in tumor tissues. CONCLUSION: Our study suggests that WA synergistically enhances the antitumor effect of Sora, offering promising implications for evolving treatment approaches for HCC.

Discovery of cinnamylaldehyde-derived mono-carbonyl curcumin analogs as anti-gastric cancer agents via suppression of STAT3 and AKT pathway.

The structural modification of curcumin has always been a hotspot in drug development. In this paper, a class of cinnamylaldehyde-derived mono-carbonyl curcumin analogs (MCAs) with 7-carbon-links were designed and synthesized and their anticancer properties were evaluated. Through screening anti-gastric cancer activity of these compounds, H1 exhibited the strongest cytotoxic activity by inhibiting cell viability and colony formation, inducing cell cycle G2/M phase arrest in vitro (SGC-7901 and AGS gastric cancer cells). Moreover, the SGC-7901 subcutaneous tumor-bearing mice studies revealed that H1 significantly inhibited the tumor growth of gastric cancer. We explored the possible potential targets of H1 through network pharmacology. Mechanistically, our results demonstrated that H1 showed potential anti-gastric cancer activity through suppression of the STAT3 and AKT signaling pathway in vitro and in vivo, which was validated by molecular docking. Overall, our results indicate the potential of H1 as a potent chemotherapeutic drug against gastric cancer.