Role of Oxidative Stress in Stem, Cancer, and Cancer Stem Cells

Abstract

The term ‘‘oxidative stress” refers to a cell’s state characterized by excessive production of reactive oxygen species (ROS) and oxidative stress is one of the most important regulatory mechanisms for stem, cancer, and cancer stem cells. The concept of cancer stem cells arose from observations of similarities between the self-renewal mechanism of stem cells and that of cancer stem cells, but compared to normal stem cells, they are believed to have no control over the cell number. ROS have been implicated in diverse processes in various cancers, and generally the increase of ROS in cancer cells is known to play an important role in the initiation and progression of cancer. Additionally, ROS have been considered as the most significant mutagens in stem cells; when elevated, blocking self-renewal and at the same time, serving as a signal stimulating stem cell differentiation. Several signaling pathways enhanced by oxidative stress are suggested to have important roles in tumorigenesis of cancer or cancer stem cells and the self-renewal ability of stem or cancer stem cells. It is now well established that mitochondria play a prominent role in apoptosis and increasing evidence supports that apoptosis and autophagy are physiological phenomena closely linked with oxidative stress. This review elucidates the effect and the mechanism of the oxidative stress on the regulation of stem, cancer, and cancer stem cells and focuses on the cell signaling cascades stimulated by oxidative stress and their mechanism in cancer stem cell formation, as very little is known about the redox status in cancer stem cells. Moreover, we explain the link between ROS and both of apoptosis and autophagy and the impact on cancer development and treatment. Better understanding of this intricate link may shed light on mechanisms that lead to better modes of cancer treatment.

The role of proto-oncogene GLI1 in pituitary adenoma formation and cell survival regulation

“…These adaption mechanisms are hypothesized to be responsible for radiation resistance in tumor therapy that targets cancer cells through induction of oxidative stress (Huang et al 2012). Even though the redox status of CSCs is largely unknown, it was shown that adult stem cells have a lower level of ROS than more mature cells, probably to maintain the stem cell character (Dayem et al 2010, Huang et al 2012. Therefore, it is assumed that CSCs have upregulated levels of antioxidant scavenger mechanisms that protect CSCs and contribute to radiation therapy resistance (Ogawa et al 2013).…”

Synthesis and antioxidant activities of some new triheterocyclic compounds containing benzimidazole, thiophene, and 1,2,4-triazole rings

“…The melting points were determined on capillary tubes on a Büchi oil heated melting point apparatus (Essen, Germany) and uncorrected. 1 H NMR and 13 C NMR spectra were performed on Varian-Mercury 400 MHz spectrophotometer (Varian, Darmstadt, Germany) in DMSO-d 6 using TMS as internal. Splitting patterns were designated as follows: s: singlet; d: doublet; m: multiplet.…”

“…Free radicals are mainly generated by metabolic processes in the human body, and some radicals have essential roles in normal cell processes such as neural signal transduction 1 . On the other hand, excessive free radical incursion, causing very important diseases, can damage all components of the cell including DNA, proteins, and lipids 2 .…”

Roles of Oxidative Stress in the Development and Progression of Breast Cancer

“…Products derived from this injury are used as biomarkers of oxidative stress in the assessment and diagnosis of all cancers. Especially breast cancer (Gonenc et al, 2005;Dayem et al, 2010;Sosa et al, 2013).…”