Synergistic effects of methyl 2-cyano-3,11-dioxo-18beta-olean-1,-12-dien-30-oate and erlotinib on erlotinib-resistant non-small cell lung cancer cells

Ginsenoside Rk1 induces autophagy-dependent apoptosis in hepatocellular carcinoma by AMPK/mTOR signaling pathway

Hepatocellular carcinoma (HCC) is the third most lethal cancer in the world. Recent studies have shown that suppression of autophagy plays an important role in the development of HCC. Ginsenoside Rk1 is a protopanaxadiol saponin isolated from ginseng and has a significant anti-tumor effect, but its role and mechanism in HCC are still unclear. In this study, a mouse liver cancer model induced by diethylnitrosamine and carbon tetrachloride (DEN + CCl4) was employed to investigate the inhibitory effect of Rk1 on HCC. The results demonstrate that ginsenoside Rk1 effectively inhibits liver injury, liver fibrosis, and cirrhosis during HCC progression. Transcriptome data analysis of mouse liver tissue reveals that ginsenoside Rk1 significantly regulates the AMPK/mTOR signaling pathway, autophagy pathway, and apoptosis pathway. Subsequent studies show that ginsenoside Rk1 induces AMPK protein activation, upregulates the expression of autophagy marker LC3-II protein to promote autophagy, and then downregulates the expression of Bcl2 protein to trigger a caspase cascade reaction, activating AMPK/mTOR-induced toxic autophagy to promote cells death. Importantly, co-treatment of ginsenoside Rk1 with autophagy inhibitors can inhibit apoptosis of HCC cells, once again demonstrating the ability of ginsenoside Rk1 to promote autophagy-dependent apoptosis. In conclusion, our study demonstrates that ginsenoside Rk1 inhibits the development of primary HCC by activating toxic autophagy to promote apoptosis through the AMPK/mTOR pathway. These findings confirm that ginsenoside Rk1 is a promising new strategy for the treatment of HCC.

Application of SNAP-tag-EGFR cell membrane chromatography model in screening antitumor active components of Silybum marianum (L.) Gaertn

The SNAP-tag-epidermal growth factor receptor (SNAP-tag-EGFR) cell membrane chromatography (CMC) model is a powerful tool for investigating ligand-receptor interactions and screening active ingredients in traditional Chinese medicine. Most tyrosine kinase inhibitors (TKIs) target epidermal growth factor receptors. However, TKIs associated with significant side effects and drug resistance must be addressed immediately. Therefore, there is an urgent need to develop new TKIs with high efficiency and low toxicity. Because of its low toxicity and side effects, traditional Chinese medicine has been widely employed to treat various diseases, including cancer. Hence, this study aimed to use the SNAP-tag-EGFR/CMC-high-performance liquid chromatography-mass spectrometry (HPLC-MS) two-dimensional system model as the research tool to screen and identify potential EGFR antagonists from the Chinese medicine Silybum marianum (L.) Gaertn. The applicability of the system was verified using the positive control drug osimertinib. Four potential EGFR antagonists were screened from the Chinese medicine Silybum marianum (L.) Gaertn.. They were identified as silydianin, silychristin, silybin, and isosilybin. Additionally, their pharmacological activity was preliminarily verified using a CCK-8 assay. The kinetic parameters of the four active ingredients interacting with EGFR and their binding modes with EGFR were analyzed using nonlinear chromatography (NLC) and molecular docking. This study identified silydianin, silychristin, silybin, and isosilybin from Silybum marianum (L.) Gaertn. and verified their potential antitumor effects on EGFR.

Ginsenoside Rk3 is a novel PI3K/AKT-targeting therapeutics agent that regulates autophagy and apoptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. Ginsenoside Rk3, an important and rare saponin in heat-treated ginseng, is generated from Rg1 and has a smaller molecular weight. However, the anti-HCC efficacy and mechanisms of ginsenoside Rk3 have not yet been characterized. Here, we investigated the mechanism by which ginsenoside Rk3, a tetracyclic triterpenoid rare ginsenoside, inhibits the growth of HCC. We first explored the possible potential targets of Rk3 through network pharmacology. Both in vitro (HepG2 and HCC-LM3 cells) and in vivo (primary liver cancer mice and HCC-LM3 subcutaneous tumor-bearing mice) studies revealed that Rk3 significantly inhibits the proliferation of HCC. Meanwhile, Rk3 blocked the cell cycle in HCC at the G1 phase and induced autophagy and apoptosis in HCC. Further proteomics and siRNA experiments showed that Rk3 regulates the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway to inhibit HCC growth, which was validated by molecular docking and surface plasmon resonance. In conclusion, we report the discovery that ginsenoside Rk3 binds to PI3K/AKT and promotes autophagy and apoptosis in HCC. Our data strongly support the translation of ginsenoside Rk3 into novel PI3K/AKT-targeting therapeutics for HCC treatment with low toxic side effects.

Boosting ferroptosis and microtubule inhibition for antitumor therapy via a carrier-free supermolecule nanoreactor

Traditional microtubule inhibitors fail to significantly enhance the effect of colorectal cancer; hence, new and efficient strategies are necessary. In this study, a supramolecular nanoreactor (DOC@TA-Fe³⁺) based on tannic acid (TA), iron ion (Fe³⁺), and docetaxel (DOC) with microtubule inhibition, reactive oxygen species (ROS) generation, and glutathione peroxidase 4 (GPX4) inhibition, is prepared for ferroptosis/apoptosis treatment. After internalization by CT26 cells, the DOC@TA-Fe³⁺ nanoreactor escapes from the lysosomes to release payloads. The subsequent Fe³⁺/Fe²⁺ conversion mediated by TA reducibility can trigger the Fenton reaction to enhance the ROS concentration. Additionally, Fe³⁺ can consume glutathione to repress the activity of GPX4 to induce ferroptosis. Meanwhile, the released DOC controls microtubule dynamics to activate the apoptosis pathway. The superior in vivo antitumor efficacy of DOC@TA-Fe³⁺ nanoreactor in terms of tumor growth inhibition and improved survival is verified in CT26 tumor-bearing mouse model. Therefore, the nanoreactor can act as an effective apoptosis and ferroptosis inducer for application in colorectal cancer therapy.