Molecular mechanism of ion channel protein TMEM16A regulated by natural product of narirutin for lung cancer adjuvant treatment

Cancer chemotherapy drugs are widely criticized for their serious side effects and low cure rate. Therefore, adjuvant therapy as a combination with chemotherapy administration is being accepted by many patients. However, unclear drug targets and mechanisms limit the application of adjuvant treatment. In this study, we confirmed TMEM16A is a key drug target for lung adenocarcinoma, and narirutin is an effective anti-lung adenocarcinoma natural product. Virtual screening and fluorescence experiments confirmed that narirutin inhibits the molecular target TMEM16A, which is specific high-expression in lung adenocarcinoma. Molecular dynamics simulations and electrophysiological experiments revealed the precise molecular mechanism of narirutin regulating TMEM16A. The anticancer effect of narirutin and its synergistic effect on cisplatin were explored by cell proliferation, migration, and apoptosis assays. The signaling pathways regulated by narirutin were analyzed by western blot. Tumor xenograft mice experiments demonstrated the synergistic anticancer effect of narirutin and cisplatin, and the side effects of high concentrations of cisplatin were almost eliminated. Pharmacokinetic experiments showed the biological safety of narirutin is satisfactory in vivo. Based on the significant anticancer effect and high biosafety, naringin has great potential as a functional food in the adjuvant treatment of lung cancer.

……

To screen for safe and reliable TMEM16A inhibitors, the molecular docking software Vina [37] was used to perform virtual screening of a compound library containing >5000 natural products (provided by Chengdu DeSiTe Biological Technology Co., Ltd. of China, http:// www.028desite.com/). The calcium-bound structure of TMEM16A (PDB ID: 5OYB) was programmed to be docking receptor. The extracellular vestibule of the TMEM16A channel as the inhibitor binding pocket was set to docking box. The PDBQT files of TMEM16A and ligands were prepared by Autodock [38], TMEM16A was set to rigid, and the ligand was flexible. The grid center was determined according to the center of the binding pocket, and the searching space size was 24 Å3. The global search exhaustiveness value was set to 50. The maximum energy difference between the optimal binding mode and the worst case was set to 5 kcal/mol to ensure diverse docked poses.

…………