Therapeutic Potential of Chemical Compounds in Targeting Cancer Stem Cells

Abstract

Despite a wide range of targeted therapies being employed against cancer, the conventional treatment modules fail to inhibit recurrence. The primary reason for this failure is intratumor heterogeneity, maintained by the cancer stem cells (CSCs). The CSCs share a healthy stem cell’s regenerative property and redox state. However, the reactive oxygen species (ROS) levels cross the threshold in a tumorigenic condition. The redox state within CSCs maintains low ROS levels; hence these cells go undetected when treated with the conventional drugs and radiation therapies that target high ROS levels in differentiated tumor cells. The resistant CSCs with subliminal ROS levels increase the chances of tumor recurrence substantially. Therefore, it is necessary to devise more target-specific therapies that pivot CSCs. This chapter elaborates on the mechanisms by which CSCs maintain their redox state. ROS’s role in tumor progression concerning the tumor microenvironment (TME) and the endogenous molecules that regulate the ROS levels within tumorigenic compared to non-tumorigenic cells has been described. These molecules include the genes, proteins, and miRNAs of different signaling cascades that prevent inflammation, DNA damage, and cytotoxicity by keeping the ROS levels within the cell below a defined threshold. The second section summarizes the anticancer drugs and molecules that target ROS within the CSCs, either through a prooxidant or antioxidant approach. Conclusively, the present chapter would likely provide information on possible drug combinations, which can be explicitly used against CSCs.KeywordsCancer stem cells (CSCs)Reactive oxygen species (ROS)ProoxidantAntioxidantDrug resistance