Cancer stem cells and resistance to chemo and radio therapy

Abstract

Cancer stem cells (CSCs, or tumor initiating cells) are responsible for tumor initiation. If cancer treatment kills most of cancer cells in the stage of transit amplifying and differentiation without killing the stem cells, the surviving CSCs will eventually lead to recurrence of tumors. Studies have suggested that CSCs may be the primary mediators of resistance to chemo- and radio-therapy, leading to failure in cancer therapy. Numerous targets are being investigated for their potential involvement in the self-renewal and chemo- and radio-resistance of cancer cells. However, despite the intensive efforts invested into characterizing the role of cancer stem cells, there is a sense of uncertainty regarding the identity and number of these cells as well as the implications in cancer treatment. In this review, we will discuss the identification of CSCs by cell surface markers, the biology of CSCs, and the role of CSCs in resistance to radio- and chemo-therapy. This review will discuss the advances in targeting CSCs to improve the efficacy of chemo- and radio-therapy.

Specific role of JNK in the maintenance of the tumor-initiating capacity of A549 human non-small cell lung cancer cells

“…Indeed, aberrant activation of JNK has been increasingly reported in a variety of human cancers, and the roles of JNK in the control of fundamental cellular properties of cancer cells, such as proliferation, survival and migration, have been documented (2)(3)(4)(5). Significantly, adding to such roles of JNK in cancer cells in general, we and others have recently identified a specific role of JNK in the control of cancer stem cells (CSCs) of glioblastoma (5-7), a particular subpopulation of cancer cells now presumed to have a pivotal role in cancer relapse and/or metastasis as well as in therapy resistance (8,9). Most importantly, we demonstrated for the first time in our recent study that 'sustained' JNK activity is not only required for the prevention of differentiation and maintenance of the 'stem cell state' of glioblastoma CSCs but also for the maintenance of their 'tumor-initiating capacity'.…”

Chemical Proteomic Approaches Targeting Cancer Stem Cells: A Review of Current Literature

“…They contribute to resistance of cancer to standard anticancer therapies (1)(2)(3)(4)(5)(6)(7). In this regard, CSCs might be the most crucial target for developing treatment of cancer.…”

PLK1 Inhibition Down-regulates Polycomb Group Protein BMI1 via Modulation of the miR-200c/141 Cluster

“…*, p Ͻ 0.05 (significant); NS, not significant. bulk of the tumor, and are resistant to most chemotherapeutic agents (44). Because CSCs are resistant to most therapeutics, they play a key role in tumor dormancy and disease recurrence.…”