ginsenoside-rg3 and Adenocarcinoma-of-Lung

Chemotherapy is a commonly used strategy for advanced lung cancer patients. However, its clinical application is restrained due to its toxicity and drug resistance. Ginsenoside Rg3 (Rg3) has a strong anticancer influence on colon cancer, breast cancer, lung cancer, and other malignant tumors. However, it is still unclear whether Rg3 can cooperate with 5-FU to inhibit the tumor growth and angiogenesis of lung adenocarcinoma (LUAD). This study examined the combined treatment of Rg3 and 5-FU in LUAD. It was revealed that the combined treatment could notably enhance the suppression on proliferative, invasive, and migratory abilities and angiogenesis in LUAD cells A549 and SPC-A-1. On the other hand, we also discovered that Rg3 or 5-FU could suppress the activity of the NF-

Topics: Adenocarcinoma of Lung; Cell Line, Tumor; Fluorouracil; Ginsenosides; Humans; Lung Neoplasms

Ginsenoside Rg3 (Rg3), a pharmacologically active compound from red ginseng, has been reported to induce cell death in various cancer cell lines, although the specific mechanisms have not been well established. In the present study, Rg3 treatment to A549 human lung adenocarcinoma led to cell death via not only apoptotic pathways but also the downregulation of epidermal growth factor receptor (EGFR). We used cross-linker and cell enzyme-linked immunosorbent assays to show that Rg3 inhibited EGFR dimerization by EGF stimulation and caused EGFR internalization from the cell membrane. Among several important phosphorylation sites in cytoplasmic EGFR, Rg3 increased the phosphorylation of tyrosine 1045 (pY1045) and serine 1046/1047 (pS1046/1047) for EGFR degradation and coincidently, attenuated pY1173 and pY1068 for mitogen-activated protein kinase activity. These effects were amplified under EGF-pretreated Rg3 stimulation. In vivo experiments showed that the average volume of the tumors treated with 30 mg/kg of Rg3 was significantly decreased by 40% compared with the control. Through immunohistochemistry, we detected the fragmentation of DNA, the accumulation of Rg3, and the reduction of EGFR expression in the Rg3-treated groups. Here, we provide the first description of the roles of Rg3 in the reduction of cell surface EGFR, the attenuation of EGFR signal transduction, and the eventual activation of apoptosis in A549 human lung adenocarcinoma.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Down-Regulation; ErbB Receptors; Ginsenosides; Humans; Lung; Lung Neoplasms; Male; Mice, Inbred C57BL; Panax; Protein Multimerization; Proteolysis