Abstract

Rhodiola is a high altitude perennial plant that is widespread in Eastern Europe and Asia. The root of the Rhodiola plant has been used for many years in eastern traditional medicine and it is well known for cardio-protective and central nervous system enhancement effects. It is considered a plant-derived “adaptogen” which is capable of maintaining a physiological homeostasis upon exposure to stress. The Rhodiola rosea and Rhodiola crenulata species have been shown to elicit anti-tumor activities in vitro and in vivo. Here we show thatR. crenulata is able to block several characteristics associated with cancer stem cell behavior including migration, invasion, resistance to anoikis and tumorsphere formation. In addition, we show that R. crenulata regulates the mRNA expression levels of Id (Inhibitor of differentiation or Inhibitor of DNA-binding) proteins, which play several key roles in development, cell cycle regulation and tumorigenesis.

Key words: Breast cancer, rhodiola, metastasis, stem cells, CD44^high/CD24^low, anoikis, SFRP1, Id-1, Id-2, Id-3.