Cancer stem cells

Author(s):  
Connor Sweeney ◽  
Lynn Quek ◽  
Betty Gration ◽  
Paresh Vyas

The concept of cancer stem cells (CSCs) emerged from our understanding of the way in which normal tissues are generated from multipotent stem cells. Regenerative tissues exhibit a cellular hierarchy of differentiation, which is maintained by stem cells. Evidence from experimental models has indicated that a similar hierarchy is seen in at least some cancers, where CSCs give rise to disordered and dysfunctional tissues, leading to disease. The CSC model proposes that tumours can be divided into at least two distinct populations. The stem cells are a specialized population of cancer cells with the unique property of long-term self-renewal that maintain the growth of the cancerous clone. These stem cells give rise to the second population of cells, which form the bulk of the tumour, and lack indefinite self-renewal. Recently, our understanding of CSCs has been refined through combining genetic, epigenetic, and functional models of tumorigenesis. Malignant transformation occurs as the result of sequential acquisition of genetic mutations. Capacity for self-renewal is essential for a clone to survive and progress to become cancerous. If an oncogenic mutation occurs in a cell that is incapable of self-renewal, the clone will become exhausted through differentiation. CSCs may survive anticancer chemotherapy and increasing evidence indicates their role in mediating treatment resistance and relapse. Therefore, strategies to eradicate cancers must effectively target the stem cells that maintain their growth. CSC-directed therapeutic strategies are currently being explored in experimental studies and clinical trials but reducing toxicity to normal tissue stem cells represents a significant challenge.

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Chen-Hsi Hsieh ◽  
K. S. Clifford Chao ◽  
Hui-Fen Liao ◽  
Yu-Jen Chen

Cancer stem cells (CSCs) existing in human cancers have been demonstrated to be a major cause of cancer treatment resistance, invasion, metastasis, and relapse. Self-renewal pathways, Wnt/β-catenin, Sonic hedgehog (Shh), and the Notch signaling pathway play critical roles in developing CSCs and lead to angiogenesis, migration, invasion, and metastasis. Multidrug resistance (MDR) is an unfavorable factor causing the failure of treatments against cancer cells. The most important and thoroughly studied mechanism involved in MDR is the active efflux of chemotherapeutic agents through membrane drug transporters. There is growing evidence that Norcantharidin (NCTD), a water-soluble synthetic small molecule derivative of naturally occurring cantharidin from the medicinal insect blister beetle (Mylabris phalerataPallas), is capable of chemoprevention and tumor inhibition. We summarize investigations into the modulation of self-renewal pathways and MDR in CSCs by NCTD. This review may aid in further investigation of using NCTD to develop more effective strategies for cancer treatment to reduce resistance and recurrence.


2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 2-3
Author(s):  
J Douchin ◽  
V Giroux

Abstract Background Esophageal cancer is a particularly deadly cancer with a 5-year survival rate of only 14% in Canada. Treatment resistance ascribed for at least 30% of the death. The acquisition of resistance to radio- and chemotherapy is mostly attributed to the presence of cancer stem cells (CSCs) and their persistence following classical treatments. CSCs are a subpopulation of tumor cells with high self-renewal and multipotent capacity which amongst others contribute to tumor heterogeneity. Our previous work identified Krt15+ esophageal cells as a rare and long-lived subpopulation of basal cells with higher self-renewal and multipotent capacities than other basal cells. Furthermore, preliminary observations suggest that Krt15+ cells could act as the cell-of-origin for ESCC, the most prevalent type of esophageal cancer worldwide. Though, we still ignore the role of Krt15+ cells in later stages of esophageal cancer such as treatment resistance and if therefore, they could act as CSC. Aims Determine if Krt15+ cells act as CSCs in ESCC patients and if they could contribute to treatment resistance. Methods To do so, we used Krt15-CrePR1;R26mT/mG mice treated with the carcinogen 4 Nitroquinoline-1-oxide (4NQO) in their drinking water for 16 weeks to induce ESCC. Twelve weeks following the beginning of 4NQO treatment, we induced Cre recombination with RU486, a PR1 agonist, leading to GFP expression specifically in Krt15+ cells. Following 4NQO treatment, mice were put back on normal water for 8 to 12 weeks allowing tumors to grow. At euthanasia, esophageal tumor cells were FACS sorted to isolate Krt15+ (GFP+) and Krt15- (GFP-) cells, which were then grown as tumoroids. Results We first validated that 4NQO successfully induced the formation of esophageal lesions in our model, which comprises Krt15+ and Krt15- tumor cells. Tumoroids were then successfully derived from these FACS-sorted cell populations. We demonstrated the increase of CSC-like cells within Krt15+ tumoroids compared to Krt15- tumoroids by measuring the presence of CD44highCD24high cells, two well-known CSC markers, by flow cytometry. Interestingly, Krt15+ and Krt15- tumoroids are histologically distinct. As observed for normal cells, Krt15+ tumoroids appeared as more multipotent and heterogenous than Krt15- tumoroids. Furthermore, Krt15+ tumoroids display higher hyperplasia than Krt15- tumoroids suggesting that Krt15+ tumor cells are functionally distinct from Krt15- tumor cells. Conclusions Krt15+ tumoroids display higher CSC content and hyperplastic capacity suggesting their potential role in esophageal cancer. With this project, we aim to highlight the role of Krt15+ cells in treatment resistance and put forward new targets to overcome this deadly issue in ESCC patients. Funding Agencies CAGCanada research chair TIER 2


2019 ◽  
Vol 26 (11) ◽  
pp. 1994-2050 ◽  
Author(s):  
Annamaria Sandomenico ◽  
Menotti Ruvo

Background:Elucidating the mechanisms of recurrence of embryonic signaling pathways in tumorigenesis has led to the discovery of onco-fetal players which have physiological roles during normal development but result aberrantly re-activated in tumors. In this context, Nodal and Cripto-1 are recognized as onco-developmental factors, which are absent in normal tissues but are overexpressed in several solid tumors where they can serve as theranostic agents.Objective:To collect, review and discuss the most relevant papers related to the involvement of Nodal and Cripto-1 in the development, progression, recurrence and metastasis of several tumors where they are over-expressed, with a particular attention to their occurrence on the surface of the corresponding sub-populations of cancer stem cells (CSC).Results:We have gathered, rationalized and discussed the most interesting findings extracted from some 370 papers related to the involvement of Cripto-1 and Nodal in all tumor types where they have been detected. Data demonstrate the clear connection between Nodal and Cripto-1 presence and their multiple oncogenic activities across different tumors. We have also reviewed and highlighted the potential of targeting Nodal, Cripto-1 and the complexes that they form on the surface of tumor cells, especially of CSC, as an innovative approach to detect and suppress tumors with molecules that block one or more mechanisms that they regulate.Conclusion:Overall, Nodal and Cripto-1 represent two innovative and effective biomarkers for developing potential theranostic anti-tumor agents that target normal as well as CSC subpopulations and overcome both pharmacological resistance and tumor relapse.


2019 ◽  
Vol 14 (5) ◽  
pp. 428-436 ◽  
Author(s):  
Gabriele D. Bigoni-Ordóñez ◽  
Daniel Czarnowski ◽  
Tyler Parsons ◽  
Gerard J. Madlambayan ◽  
Luis G. Villa-Diaz

Cancer is a highly prevalent and potentially terminal disease that affects millions of individuals worldwide. Here, we review the literature exploring the intricacies of stem cells bearing tumorigenic characteristics and collect evidence demonstrating the importance of integrin α6 (ITGA6, also known as CD49f) in cancer stem cell (CSC) activity. ITGA6 is commonly used to identify CSC populations in various tissues and plays an important role sustaining the self-renewal of CSCs by interconnecting them with the tumorigenic microenvironment.


Author(s):  
Nese Unver

: Cancer stem cells represent a rare subpopulation of cancer cells carrying self-renewal and differentiation features in the multi-step tumorigenesis, tumor recurrence and metastasis. Pro-inflammatory stress is highly associated with cancer stemness via induction of cytokines, tumor-promoting immune cells and cancer stemness-related signaling pathways. This review summarizes the major pro-inflammatory factors affecting cancer stem cell characteristics and the critical immunotherapeutic strategies to eliminate cancer stem cells.


Author(s):  
Milad Ashrafizadeh ◽  
Shahram Taeb ◽  
Hamed Haghi-Aminjan ◽  
Shima Afrashi ◽  
Kave Moloudi ◽  
...  

: Resistance of cancer cells to therapy is a challenge for achieving an appropriate therapeutic outcome. Cancer (stem) cells possess several mechanisms for increasing their survival following exposure to toxic agents such as chemotherapy drugs, radiation as well as immunotherapy. Evidences show that apoptosis plays a key role in response of cancer (stem) cells and their multi drug resistance. Modulation of both intrinsic and extrinsic pathways of apoptosis can increase efficiency of tumor response and amplify the therapeutic effect of radiotherapy, chemotherapy, targeted therapy and also immunotherapy. To date, several agents as adjuvant have been proposed to overcome resistance of cancer cells to apoptosis. Natural products are interesting because of low toxicity on normal tissues. Resveratrol is a natural herbal agent that has shown interesting anti-cancer properties. It has been shown to kill cancer cells selectively, while protecting normal cells. Resveratrol can augment reduction/oxidation (redox) reactions, thus increases the production of ceramide and the expression of apoptosis receptors such as Fas ligand (FasL). Resveratrol also triggers some pathways which induce mitochondrial pathway of apoptosis. On the other hand, resveratrol has an inhibitory effect on anti-apoptotic mediators such as nuclear factor κ B (NFκB), cyclooxygenase-2 (COX-2), phosphatidylinositol 3–kinase (PI3K) and mTOR. In this review, we explain the modulatory effects of resveratrol on apoptosis, which can augment the therapeutic efficiency of anti-cancer drugs or radiotherapy.


Cancers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 54
Author(s):  
Margaret L. Dahn ◽  
Paola Marcato

Cancer stem cells (CSCs) are functionally defined in our laboratories by their impressive tumor-generating and self-renewal capacity; clinically, CSCs are of interest because of their enhanced capacity to evade conventional therapies [...]


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jianyu Wang ◽  
Doudou Liu ◽  
Zhiwei Sun ◽  
Ting Ye ◽  
Jingyuan Li ◽  
...  

AbstractIt has been postulated that cancer stem cells (CSCs) are involved in all aspects of human cancer, although the mechanisms governing the regulation of CSC self-renewal in the cancer state remain poorly defined. In the literature, both the pro- and anti-oncogenic activities of autophagy have been demonstrated and are context-dependent. Mounting evidence has shown augmentation of CSC stemness by autophagy, yet mechanistic characterization and understanding are lacking. In the present study, by generating stable human lung CSC cell lines with the wild-type TP53 (A549), as well as cell lines in which TP53 was deleted (H1229), we show, for the first time, that autophagy augments the stemness of lung CSCs by degrading ubiquitinated p53. Furthermore, Zeb1 is required for TP53 regulation of CSC self-renewal. Moreover, TCGA data mining and analysis show that Atg5 and Zeb1 are poor prognostic markers of lung cancer. In summary, this study has elucidated a new CSC-based mechanism underlying the oncogenic activity of autophagy and the tumor suppressor activity of p53 in cancer, i.e., CSCs can exploit the autophagy-p53-Zeb1 axis for self-renewal, oncogenesis, and progression.


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