Peroxiredoxin II Regulates Cancer Stem Cells and Stemness-Associated Properties of Cancers

Cancer stem cells (CSCs) represent a sub-population of cancer cells with the ability to regulate stemness-associated properties which are specifically responsible for unlimited growth of cancers, generation of diverse cancer cells in differentiated state and resistance to existing chemotherapy and radiotherapy. Even though, current therapies destroy majority of cancer cells, it is believed to leave CSCs without eradicating which may be the conceptualization for chemoresistance and radio-resistance. Reactive oxygen species (ROS) maintain stem cells and regulate the stemness-associated properties of cancers. Beyond the maximum limit, ROS can damage cellular functions of cancers by subjecting them to oxidative stress. Thus, maintenance of ROS level plays an important role in cancers to regulate stemness-associated properties. Peroxiredoxin II (Prx II) is a member of peroxiredoxin antioxidant enzyme family which considers as a regulator of ROS in cellular environments by modulating redox status to maintain CSC phenotype and stemness properties. Prx II has cell type-dependent expression in various types of cancer cells and overexpression or silenced expression of Prx II in cancers is associated with stem cell phenotype and stemness-associated properties via activation or deactivation of various signaling pathways. In this review, we summarized available studies on Prx II expression in cancers and the mechanisms by which Prx II takes parts to regulate CSCs and stemness-associated properties. We further discussed the potential therapeutic effects of altering Prx II expression in cancers for better anticancer strategies by sensitizing cancer cells and stem cells to oxidative stress and inhibiting stemness-associated properties.

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Chronic Oxidative Stress Promotes Molecular Changes Associated with Epithelial Mesenchymal Transition, NRF2, and Breast Cancer Stem Cell Phenotype

Antioxidants ◽

10.3390/antiox8120633 ◽

2019 ◽

Vol 8 (12) ◽

pp. 633 ◽

Cited By ~ 5

Author(s):

Ana Čipak Gašparović ◽

Lidija Milković ◽

Nadia Dandachi ◽

Stefanie Stanzer ◽

Iskra Pezdirc ◽

...

Keyword(s):

Breast Cancer ◽

Oxidative Stress ◽

Stem Cells ◽

Cancer Stem Cells ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Therapy Resistance ◽

Mesenchymal Transition ◽

Chronic Oxidative Stress ◽

Emt Markers

Oxidative stress plays a role in carcinogenesis, but it also contributes to the modulation of tumor cells and microenvironment caused by chemotherapeutics. One of the consequences of oxidative stress is lipid peroxidation, which can, through reactive aldehydes such as 4-hydroxy-2-nonenal (HNE), affect cell signaling pathways. On the other hand, cancer stem cells (CSC) are now recognized as a major factor of malignancy by causing metastasis, relapse, and therapy resistance. Here, we evaluated whether oxidative stress and HNE modulation of the microenvironment can influence CSC growth, modifications of the epithelial to mesenchymal transition (EMT) markers, the antioxidant system, and the frequency of breast cancer stem cells (BCSC). Our results showed that oxidative changes in the microenvironment of BCSC and particularly chronic oxidative stress caused changes in the proliferation and growth of breast cancer cells. In addition, changes associated with EMT, increase in glutathione (GSH) and Nuclear factor erythroid 2-related factor 2 (NRF2) were observed in breast cancer cells grown on HNE pretreated collagen and under chronic oxidative stress. Our results suggest that chronic oxidative stress can be a bidirectional modulator of BCSC fate. Low levels of HNE can increase differentiation markers in BCSC, while higher levels increased GSH and NRF2 as well as certain EMT markers, thereby increasing therapy resistance.

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HIF-1 regulates CD47 expression in breast cancer cells to promote evasion of phagocytosis and maintenance of cancer stem cells

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1520032112 ◽

2015 ◽

Vol 112 (45) ◽

pp. E6215-E6223 ◽

Cited By ~ 122

Author(s):

Huimin Zhang ◽

Haiquan Lu ◽

Lisha Xiang ◽

John W. Bullen ◽

Chuanzhao Zhang ◽

...

Keyword(s):

Breast Cancer ◽

Stem Cells ◽

Stem Cell ◽

Cancer Stem Cells ◽

Cancer Stem Cell ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Molecular Mechanisms ◽

Hypoxia Inducible Factor ◽

Cell Phenotype

Increased expression of CD47 has been reported to enable cancer cells to evade phagocytosis by macrophages and to promote the cancer stem cell phenotype, but the molecular mechanisms regulating CD47 expression have not been determined. Here we report that hypoxia-inducible factor 1 (HIF-1) directly activates transcription of the CD47 gene in hypoxic breast cancer cells. Knockdown of HIF activity or CD47 expression increased the phagocytosis of breast cancer cells by bone marrow-derived macrophages. CD47 expression was increased in mammosphere cultures, which are enriched for cancer stem cells, and CD47 deficiency led to cancer stem cell depletion. Analysis of datasets derived from thousands of patients with breast cancer revealed that CD47 expression was correlated with HIF target gene expression and with patient mortality. Thus, CD47 expression contributes to the lethal breast cancer phenotype that is mediated by HIF-1.

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Cross talk between tumor stroma and cancer cells plays a critical role in progressive enrichment of cancer stem cell phenotype in primary breast tumors

10.1101/2020.06.15.152355 ◽

2020 ◽

Author(s):

Ninjit Dhanota ◽

Amanjit Bal ◽

Gurpreet Singh ◽

Sunil K Arora

Keyword(s):

Breast Cancer ◽

Stem Cells ◽

Cancer Stem Cells ◽

Cancer Cells ◽

Stromal Cells ◽

Breast Tumors ◽

Clinicopathological Parameters ◽

Cell Phenotype ◽

Mesenchymal Transition ◽

Tumor Mass

AbstractIn order to delineate the underlying molecular mechanisms responsible for intra tumoral enrichment of BCSCs in aggressive breast tumors, firstly we evaluated the frequency and characteristics of breast cancer stem cells (BCSCs) within the tumor mass as well as in pathologically normal adjacent tissues in primary breast carcinomas of various clinical and histological grades. Then, we evaluated the expression profiles of various genes in non-cancer stem cells from these tumors to delineate the role played by cellular niche in de novo origin and/or expansion of intra-tumoral cancer stem cells.The study included primary tumor and adjacent normal breast tissue specimens from chemotherapy-naïve breast carcinoma patients. The BCSCs, identified as Lin-CD44+CD24- and aldehyde dehydrogenase 1 A1 positive were enumerated. The frequency of intra-tumoral BCSCs was correlated with various clinicopathological parameters of breast cancer. The flow-cytometrically sorted stromal cells and cancer cells from treatment naïve primary breast tumors were processed for gene expression profiling using a custom designed PCR array of genes known to facilitate cancer cell proliferation and disease progression.The frequency of BCSCs within the tumor mass as well as in the adjacent normal tissue correlated significantly with histopathological and molecular grades of tumors indicating a direct relationship of BCSC with aggressive behavior of breast cancer. A significantly higher number of BCSCs was also detected in metastatic LN group as compared to non-metastatic LN. Further, a significantly increased expression of the genes associated with growth factors, cytokines & matricellular proteins in tumors with high BCSCs content (> 5%; Hi-BCSCs tumors) as compared to Lo-BCSC tumors (with <5% intratumoral BCSC content) suggested the possible contribution of stromal cells and cancer cells in intra-tumoral expansion of CSCs. Similarly, a significant up-regulation of genes associated with hypoxia and angiogenesis in Hi-BCSCs tumors further supported the role of hypoxic environment. The expression levels of genes associated with epithelial to mesenchymal transition also followed a similar pattern. On the other hand, downregulated SNAI1 gene (generally upregulated in onset of EMT) in stromal cells of Hi-BCSCs tumors suggests a post EMT environment in Hi-BCSCs tumors.The findings suggest that the molecular crosstalk between the non-BCSC niche cells and the cancer stem cells within the breast cancer microenvironment directly contribute to formation of biologically conducive conditions for expansion of cancer stem cells.

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Metabolic Escape Routes of Cancer Stem Cells and Therapeutic Opportunities

Cancers ◽

10.3390/cancers12061436 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1436 ◽

Cited By ~ 2

Author(s):

Alice Turdo ◽

Gaetana Porcelli ◽

Caterina D’Accardo ◽

Simone Di Franco ◽

Francesco Verona ◽

...

Keyword(s):

Stem Cells ◽

Cancer Stem Cells ◽

Cancer Cells ◽

Cancer Progression ◽

Stromal Cells ◽

Metabolic Reprogramming ◽

Metabolic Adaptation ◽

Therapeutic Approaches ◽

Current Therapies ◽

Oxidative Phenotype

Although improvement in early diagnosis and treatment ameliorated life expectancy of cancer patients, metastatic disease still lacks effective therapeutic approaches. Resistance to anticancer therapies stems from the refractoriness of a subpopulation of cancer cells—termed cancer stem cells (CSCs)—which is endowed with tumor initiation and metastasis formation potential. CSCs are heterogeneous and diverge by phenotypic, functional and metabolic perspectives. Intrinsic as well as extrinsic stimuli dictated by the tumor microenvironment (TME)have critical roles in determining cell metabolic reprogramming from glycolytic toward an oxidative phenotype and vice versa, allowing cancer cells to thrive in adverse milieus. Crosstalk between cancer cells and the surrounding microenvironment occurs through the interchange of metabolites, miRNAs and exosomes that drive cancer cells metabolic adaptation. Herein, we identify the metabolic nodes of CSCs and discuss the latest advances in targeting metabolic demands of both CSCs and stromal cells with the scope of improving current therapies and preventing cancer progression.

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Phenethyl Isothiocyanate Exposure Promotes Oxidative Stress and Suppresses Sp1 Transcription Factor in Cancer Stem Cells

International Journal of Molecular Sciences ◽

10.3390/ijms20051027 ◽

2019 ◽

Vol 20 (5) ◽

pp. 1027 ◽

Cited By ~ 2

Author(s):

Bijaya Upadhyaya ◽

Yi Liu ◽

Moul Dey

Keyword(s):

Oxidative Stress ◽

Stem Cells ◽

Transcription Factor ◽

Cancer Stem Cells ◽

Cancer Cells ◽

Therapy Resistance ◽

Dependent Manner ◽

Phenethyl Isothiocyanate ◽

Concentration Dependent Manner

Aldehyde dehydrogenase 1 (ALDH1) is a cytosolic marker of cancer stem cells (CSCs), which are a sub-population within heterogeneous tumor cells. CSCs associate with therapy-resistance, self-renewal, malignancy, tumor-relapse, and reduced patient-survival window. ALDH1-mediated aldehyde scavenging helps CSCs to survive a higher level of oxidative stress than regular cancer cells. Cruciferous vegetable-derived phenethyl isothiocyanate (PEITC) selectively induces reactive oxygen species (ROS), leading to apoptosis of cancer cells, but not healthy cells. However, this pro-oxidant role of PEITC in CSCs is poorly understood and is investigated here. In a HeLa CSCs model (hCSCs), the sphere-culture and tumorsphere assay showed significantly enriched ALDHhi CSCs from HeLa parental cells (p < 0.05). Aldefluor assay and cell proliferation assay revealed that PEITC treatments resulted in a reduced number of ALDHhi hCSCs in a concentration-dependent manner (p < 0.05). In the ROS assay, PEITC promoted oxidative stress in hCSCs (p ≤ 0.001). Using immunoblotting and flow cytometry techniques, we reported that PEITC suppressed the cancer-associated transcription factor (Sp1) and a downstream multidrug resistance protein (P-glycoprotein) (both, p < 0.05). Furthermore, PEITC-treatment of hCSCs, prior to xenotransplantation in mice, lowered the in vivo tumor-initiating potential of hCSCs. In summary, PEITC treatment suppressed the proliferation of ALDH1 expressing cancer stem cells as well as key factors that are involved with drug-resistance, while promoting oxidative stress and apoptosis in hCSCs.

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Role of Claudin Proteins in Regulating Cancer Stem Cells and Chemoresistance-Potential Implication in Disease Prognosis and Therapy

International Journal of Molecular Sciences ◽

10.3390/ijms21010053 ◽

2019 ◽

Vol 21 (1) ◽

pp. 53 ◽

Cited By ~ 1

Author(s):

Saiprasad Gowrikumar ◽

Amar B. Singh ◽

Punita Dhawan

Keyword(s):

Stem Cells ◽

Cell Adhesion ◽

Cancer Stem Cells ◽

Cancer Cells ◽

Therapy Resistance ◽

Cell Phenotype ◽

Potential Implication ◽

Mesenchymal Transition ◽

Cell Cell

Claudins are cell–cell adhesion proteins, which are expressed in tight junctions (TJs), the most common apical cell-cell adhesion. Claudin proteins help to regulate defense and barrier functions, as well as differentiation and polarity in epithelial and endothelial cells. A series of studies have now reported dysregulation of claudin proteins in cancers. However, the precise mechanisms are still not well understood. Nonetheless, studies have clearly demonstrated a causal role of multiple claudins in the regulation of epithelial to mesenchymal transition (EMT), a key feature in the acquisition of a cancer stem cell phenotype in cancer cells. In addition, claudin proteins are known to modulate therapy resistance in cancer cells, a feature associated with cancer stem cells. In this review, we have focused primarily on highlighting the causal link between claudins, cancer stem cells, and therapy resistance. We have also contemplated the significance of claudins as novel targets in improving the efficacy of cancer therapy. Overall, this review provides a much-needed understanding of the emerging role of claudin proteins in cancer malignancy and therapeutic management.

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The downregulation of WWOX induces epithelial–mesenchymal transition and enhances stemness and chemoresistance in breast cancer

Experimental Biology and Medicine ◽

10.1177/1535370218806455 ◽

2018 ◽

Vol 243 (13) ◽

pp. 1066-1073 ◽

Cited By ~ 1

Author(s):

Juan Li ◽

Jie Liu ◽

Pingping Li ◽

Can Zhou ◽

Peijun Liu

Keyword(s):

Breast Cancer ◽

Stem Cells ◽

Tumor Suppressor ◽

Cancer Stem Cells ◽

Cancer Cells ◽

Epithelial Mesenchymal Transition ◽

Cell Phenotype ◽

Ww Domain ◽

Mesenchymal Transition

WW domain-containing oxidoreductase (WWOX), an important tumor suppressor, is essential for regulating cell proliferation and apoptosis. Our study demonstrates that low level of WWOX is associated with the triple-negative subtype of breast cancer (TNBC), which has higher stem cell phenotype and chemoresistance. We evaluated the role of WWOX in regulation of breast cancer stem cells (BCSC) phenotype and chemoresistance. Our results showed that knockdown of WWOX increases the stemness of breast cancer cells. Meanwhile, downregulation of WWOX induces the epithelial–mesenchymal transition (EMT) and chemoresistance of breast cancer cell lines. Our findings revealed the role of the WWOX in the regulation of the BCSC population and chemotherapeutic sensitivity and may provide insights for the development of more effective therapies targeting cancer stem cells in breast cancer. Impact statement Overcoming resistance to chemotherapy is one of the fundamental issues of clinical treatment and CSCs are responsible for the poor therapeutic effects of chemotherapy. WW domain-containing oxidoreductase (WWOX), an important tumor suppressor, regulates cancer cells’ response to chemotherapy. The major finding of our study is the novel role of WWOX in the chemoresistance of breast cancer through the regulation of cell stemness and EMT. The plasticity may play a crucial role in tumor metastasis, treatment resistance and tumor recurrence. Our findings may shed new light on the alterations of BCSCs and pave the way for the discovery of novel and more effective therapies to treat breast cancer by targeting WWOX.

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