Exploring the therapeutic potential of rabdoternin E in lung cancer treatment: Targeting the ROS/p38 MAPK/JNK signaling pathway.

Lung cancer has the highest incidence and mortality rates of all cancer types in China and therefore represents a serious threat to human health. In the present study, the mechanism of rabdoternin E against the proliferation of the lung cancer cell line A549 was explored. It was found that rabdoternin E caused the accumulation of large amounts of reactive oxygen species (ROS), promoted cell S phase arrest by reducing the expression of CDK2 and cyclin A2, induced apoptosis by increasing the Bax/Bcl‑2 ratio and promoted the phosphorylation of proteins in the ROS/p38 MAPK/JNK signaling pathway, which is associated with apoptosis and ferroptosis. In addition, it was also found that Z‑VAD‑FMK (an apoptosis inhibitor), ferrostatin‑1 (ferroptosis inhibitor) and N‑acetylcysteine (a ROS inhibitor) could partially or greatly reverse the cytotoxicity of rabdoternin E to A549 cells. Similarly, NAC (N‑acetylcysteine) treatment notably inhibited the rabdoternin E‑stimulated p38 MAPK and JNK activation. Furthermore, experiments in mice revealed that Rabdoternin E markedly reduced tumor volume and weight and regulated the expression levels of apoptosis and ferroptosis‑related proteins (including Ki67, Bcl‑2, Bax, glutathione peroxidase 4, solute carrier family 7 member 11 and transferrin) in the tumor tissues of mice. Histopathological observation confirmed that the number of tumor cells decreased markedly after administration of rabdoternin E. Taken together, rabdoternin E induced apoptosis and ferroptosis of A549 cells by activating the ROS/p38 MAPK/JNK signaling pathway. Therefore, the results of the present study showed that rabdoternin E is not toxic to MCF‑7 cells (normal lung cells), had no significant effect on body weight and was effective and therefore may be a novel therapeutic treatment for lung cancer.