BRM270 inhibits cancer stem cell maintenance via microRNA regulation in chemoresistant A549 lung adenocarcinoma cells.

Chemotherapy is a standard treatment for non-small-cell lung cancer (NSCLC). However, the dose-limiting toxicity of drugs and the development of chemoresistance are major clinical challenges to successful management of NSCLC. Asian traditional medicine is gaining global attention as a non-toxic alternative to chemotherapy. BRM270 is an extract formulated from seven Asian medicinal plants that has been shown to inhibit tumor cell proliferation in diverse cancer types. We previously demonstrated that BRM270 suppresses tumorigenesis by negatively regulating nuclear factor-κB signaling in multidrug-resistant cancer stem cells (CSCs). In this study we report that the growth, migration, and invasion of normal human lung adenocarcinoma cells and their chemoresistant derivatives was inhibited by BRM270 treatment. Notably, BRM270 was found to modulate CSC self-renewal and tumor-initiating capacity via positive regulation of the miRNA-128. Thus, combination therapy with miRNA-128 and BRM270 may be an effective treatment strategy for chemoresistant NSCLC.