Published online May 7, 2013. doi: 10.3748/wjg.v19.i17.2603
Revised: February 4, 2013
Accepted: February 7, 2013
Published online: May 7, 2013
Processing time: 133 Days and 15.1 Hours
Colorectal cancer is one of the most common malignant tumors worldwide. A model of cancer development involving cancer stem cells has been put forward because it provides a possible explanation of tumor hierarchy. Cancer stem cells are characterized by their proliferation, tumorigenesis, differentiation, and self-renewal capacities, and chemoradiotherapy resistance. Due to the role of cancer stem cells in tumor initiation and treatment failure, studies of cancer stem cell markers, such as CD133, have been of great interest. CD133, a five-transmembrane glycoprotein, is widely used as a marker to identify and isolate colorectal cancer stem cells. This marker has been investigated to better understand the characteristics and functions of cancer stem cells. Moreover, it can also be used to predict tumor progression, patient survival, chemoradiotherapy resistance and other clinical parameters. In this review, we discuss the use of CD133 in the identification of colorectal cancer stem cell, which is currently controversial. Although the function of CD133 is as yet unclear, we have discussed several possible functions and associated mechanisms that may partially explain the role of CD133 in colorectal cancers. In addition, we focus on the prognostic value of CD133 in colorectal cancers. Finally, we predict that CD133 may be used as a possible target for colorectal cancer treatment.
Core tip: CD133 is not a reliable marker to identify the entire population of cancer stem cells (CSCs). However, the abundance of CD133 may be a good indicator of CSC identity and consistent with the biological characteristics of CSCs; The expression of CD133 is correlated to the poor survival; CD133(+) cells exhibit more chemoresistant behavior than CD133(-) cells; Whether CD133-targeting therapies can be a specific or efficient treatment for colorectal cancer has not been confirmed.