Mechanism on Banxia Xiexintang Inducing Ferroptosis in Gastric Cancer Cells Based on Nrf2/GPX4 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo observe the effect of Banxia Xiexintang （BXT） on the proliferation of human gastric cancer HGC-27， MKN-45， and AGS cells and its mechanism. MethodCell counting kit-8 （CCK-8） was used to detect the effects of different concentrations of BXT-containing serum （5%， 10%， and 20%） on the proliferation of HGC-27， MKN-45， and AGS cells. A mitochondrial membrane potential probe （TMRE） was used to detect the expression of mitochondrial membrane potential in cells. A kit was used to detect iron ion （Fe2+） content， lipid peroxide （LPO）， and superoxide dismutase （SOD） activity. Western blot was used to detect the protein expression levels of glycogen synthase3β （GSK3β）， phosphorylated GSK3β （p-GSK3β）， nuclear factor E2 related factor 2 （Nrf2）， and glutathione peroxidase 4 （GPX4）. The real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of member 11 of the cystine/glutamic acid reverse transporter solute vector family 7 （SLC7A11）， member 2 of the heavy chain solute vector family 3 （SLC3A2）， transferrin receptor 3 （TFRC）， and tumor protein （TP）53. ResultCCK-8 results showed that BXT and capecitabine could significantly reduce the survival rate of three kinds of gastric cancer cells after treatment with drug-containing serum for 24 h （P<0.01）. After 48 h of intervention with drug-containing serum， the survival rate of three kinds of gastric cancer cells was significantly decreased in both the capecitabine group and the BXT group compared with the blank group. The BXT group was dose-dependent， with 20% BXT having the most significant effect （P<0.01）. In terms of biochemical indicators of ferroptosis， compared with the blank group， BXT and capecitabine significantly decreased the expression of mitochondrial membrane potential （P<0.01） and SOD activity （P<0.01） and significantly increased the contents of LPO and Fe2+ （P<0.01）， so as to improve the sensitivity of gastric cancer cells to ferroptosis. In terms of the Nrf2/GPX4 pathway， compared with the blank group， the BXT group could reduce the protein expressions of p-GSK3β， Nrf2， and GPX4 （P<0.01） in gastric cancer cells and increase mRNA expressions of SLC7A11 and SLC3A2 （P<0.05）. It could also increase the protein expression of GSK3β （P<0.01） and mRNA expression of TP53 and TFRC （P<0.05， P<0.01） in gastric cancer cells. Inhibition of the Nrf2/GPX4 pathway induces ferroptosis in gastric cancer cells. Compared with the capecitabine group， the 20% BXT group showed a more obvious effect. ConclusionBanxia Xiexintang can induce ferroptosis in gastric cancer cells HGC-27， MKN-45， and AGS by inhibiting the Nrf2/GPX4 pathway.

Novel perspective in transplantation therapy of mesenchymal stem cells: targeting the ferroptosis pathway / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Ex vivo culture-amplified mesenchymal stem cells (MSCs) have been studied because of their capacity for healing tissue injury. MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells, but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period. Hence, strategies to increase the efficacy of MSC treatment are urgently needed. Iron overload, reactive oxygen species deposition, and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs, thereby hastening cell death. Notably, oxidative stress (OS) and deficient antioxidant defense induced by iron overload can result in ferroptosis. Ferroptosis may inhibit cell survival after MSC transplantation, thereby reducing clinical efficacy. In this review, we explore the role of ferroptosis in MSC performance. Given that little research has focused on ferroptosis in transplanted MSCs, further study is urgently needed to enhance the in vivo implantation, function, and duration of MSCs.

A novel anticancer property of Lycium barbarum polysaccharide in triggering ferroptosis of breast cancer cells / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Breast cancer is one of the most malignant tumors and is associated with high mortality rates among women. Lycium barbarum polysaccharide (LBP) is an extract from the fruits of the traditional Chinese herb, L. barbarum. LBP is a promising anticancer drug, due to its high activity and low toxicity. Although it has anticancer properties, its mechanisms of action have not been fully established. Ferroptosis, which is a novel anticancer strategy, is a cell death mechanism that relies on iron-dependent lipid reactive oxygen species (ROS) accumulation. In this study, human breast cancer cells (Michigan Cancer Foundation-7 (MCF-7) and MD Anderson-Metastatic Breast-231 (MDA-MB-231)) were treated with LBP. LBP inhibited their viability and proliferation in association with high levels of ferroptosis. Therefore, we aimed to ascertain whether LBP reduced cell viability through ferroptosis. We found that the structure and function of mitochondria, lipid peroxidation, and expression of solute carrier family 7 member 11 (SLC7A11, also known as xCT, the light-chain subunit of cystine/glutamate antiporter system Xc-) and glutathione peroxidase 4 (GPX4) were altered by LBP. Moreover, the ferroptosis inhibitor, Ferrostatin-1 (Fer-1), rescued LBP-induced ferroptosis-associated events including reduced cell viability and glutathione (GSH) production, accumulation of intracellular free divalent iron ions and malondialdehyde (MDA), and down-regulation of the expression of xCT and GPX4. Erastin (xCT inhibitor) and RSL3 (GPX4 inhibitor) inhibited the expression of xCT and GPX4, respectively, which was lower after the co-treatment of LBP with Erastin and RSL3. These results suggest that LBP effectively prevents breast cancer cell proliferation and promotes ferroptosis via the xCT/GPX4 pathway. Therefore, LBP exhibits novel anticancer properties by triggering ferroptosis, and may be a potential therapeutic option for breast cancer.