BMI1 Roles in Cancer Stem Cells and Its Association with MicroRNAs Dysregulation in Cancer: Emphasis on Colorectal Cancer

Context: Colorectal cancer (CRC) is among the most common cancers in the world. Despite the existence of different treatment strategies such as chemoradiation and surgery, CRC therapy still remains a significant challenge as a result of the existence of cancer stem cells (CSCs). Evidence Acquisition: This review is comprised of research and review studies published in valid databases such as PubMed, ScienceDirect, Medline, Google Scholar, and Scopus, using the following keywords: BMI1, cancer stem cell, microRNA, and colorectal cancer. BMI1 (B cell-specific Moloney murine leukemia virus integration site 1) is a key component of polycomb repressor complex 1 (PRC1) and plays a significant role in CSCs self-renewal in various types of cancer including CRC. It has been proven that BMI1, in association with deregulated microRNAs (miRNAs), can promote cell cycle progression as well as epithelial to mesenchymal transition (EMT) in cancer. BMI1 is a colon stem cell marker that is up-regulated in colon CSCs and can be taken as a promising target for CRC therapy. This review describes the role of BMI-1 in the self-renewal of CSCs and EMT in association with miRNA dysregulation (with emphasis on CRC).