Glucose metabolism‐targeted therapy and withaferin A are effective for epidermal growth factor receptor tyrosine kinase inhibitor‐induced drug‐tolerant persisters

In pathway‐targeted cancer drug therapies, the relatively rapid emergence of drug‐tolerant persisters ( DTP s) substantially limits the overall therapeutic benefit. However, little is known about the roles of DTP s in drug resistance. In this study, we investigated the features of epidermal growth factor receptor–tyrosine kinase inhibitor‐induced DTP s and explored a new treatment strategy to overcome the emergence of these DTP s. We used two EGFR ‐mutated lung adenocarcinoma cell lines, PC 9 and II ‐18. They were treated with 2 μM gefitinib for 6, 12, or 24 days or 6 months. We analyzed the mRNA expression of the stem cell‐related markers by quantitative RT ‐ PCR and the expression of the cellular senescence‐associated proteins. Then we sorted DTP s according to the expression pattern of CD 133 and analyzed the features of sorted cells. Finally, we tried to ablate DTP s by glucose metabolism targeting therapies and a stem‐like cell targeting drug, withaferin A. Drug‐tolerant persisters were composed of at least two types of cells, one with the properties of cancer stem‐like cells ( CSC s) and the other with the properties of therapy‐induced senescent ( TIS ) cells. The CD 133 high cell population had CSC properties and the CD 133 low cell population had TIS properties. The CD 133 low cell population containing TIS cells showed a senescence‐associated secretory phenotype that supported the emergence of the CD 133 high cell population containing CSC s. Glucose metabolism inhibitors effectively eliminated the CD 133 low cell population. Withaferin A effectively eliminated the CD 133 high cell population. The combination of phloretin and withaferin A effectively suppressed gefitinib‐resistant tumor growth.