Expression and Function of PPARs in Cancer Stem Cells

Cancer stem cells (CSCs) are cancer cells with characteristics of stem cells, especially the ability to arise to all types of cell in a particular cancer tissue. With the capacity to generate multiple types of cancer cells, CSCs are proposed as primary impetus for tumor initiation and metastases and are suggested as potential therapeutic targets for anti-cancer treatment. Peroxisome-proliferatoractivated receptors (PPARs) are a subset of multifunctional transcription factors which play a pivotal role in cancer development and tumorigenesis. PPARs are also reported to be involved in the modulation of the epithelial-mesenchymal transition (EMT) process in CSC initiation and in the regulation of CSC functions. However, the exact mechanisms remain unknown. Herein, we review the latest evidence on the regulatory effects and mechanisms of PPARs in CSC formation and function, and evaluate the prospects of PPARs as a target for cancer treatment.