Effects of Sensitized Sorafenib with a Paeoniflorin and Geniposide Mixture on Liver Cancer via the NF-κB-HIF-2α-SerpinB3 Pathway

Paeoniflorin Induces ER Stress-Mediated Apoptotic Cell Death by Generating Nox4-Derived ROS under Radiation in Gastric Cancer

Gastric cancer is one of the most prevalent cancer types worldwide, and its resistance to cancer therapies, such as chemotherapy and radiotherapy, has made treating it a major challenge. Paeoniflorin (PF) is one potential pharmacological treatment derived from paeony root. However, in cancer, the molecular mechanisms and biological functions of PF are still unclear. In the present study, we found that PF exerts anti-tumor effects in vivo and in vitro and induces apoptotic cell death through ER stress, calcium (Ca2+), and reactive oxygen species (ROS) release in gastric cancer cells. However, ROS inhibition by DPI and NAC blocks cell death and the PERK signaling pathway via the reduction of Nox4. Moreover, PF triggers a synergistic inhibitory effect of the epithelial-mesenchymal transition (EMT) process under radiation exposure in radiation-resistant gastric cancer cells. These findings indicate that PF-induced Ca2+ and ROS release overcomes radioresistance via ER stress and induces cell death under radiation in gastric cancer cells. Therefore, PF, in combination with radiation, may be a powerful strategy for gastric cancer therapy.

Upregulation of CSNK1A1 induced by ITGB5 confers to hepatocellular carcinoma resistance to sorafenib in vivo by disrupting the EPS15/EGFR complex

Oral multitarget tyrosine kinase inhibitors (TKIs), such as sorafenib, which suppress tumor cell proliferation and tumor angiogenesis, have been approved to treat patients with hepatocellular carcinoma (HCC). Of note, only approximately 30% of patients can benefit from TKIs, and this population usually acquires drug resistance within 6 months. In this study, we intended to explore the mechanism associated with regulating the sensitivity of HCC to TKIs. We revealed that integrin subunit β 5 (ITGB5) is abnormally expressed in HCC and contributes to decreased the sensitivity of HCC to sorafenib. Mechanistically, unbiased mass spectrometry analysis using ITGB5 antibodies revealed that ITGB5 interacts with EPS15 to prevent the degradation of EGFR in HCC cells, which activates AKT-mTOR signaling and the MAPK pathway to reduce the sensitivity of HCC cells to sorafenib. In addition, mass spectrometry analysis showed that CSNK1A1 binds to ITGB5 in HCC cells. Further study indicated that ITGB5 increased the protein level of CSNK1A1 through the EGFR-AKT-mTOR pathway in HCC. Upregulated CSNK1A1 phosphorylates ITGB5 to enhance the interaction between ITGB5 and EPS15 and activate EGFR in HCC cells. Thus, we identified a positive feedback loop between ITGB5-EPS15-EGFR-CSNK1A1 in HCC cells. This finding provides a theoretical basis for the future development of therapeutic strategies to improve the anti-HCC efficacy of sorafenib.