scholarly journals Immunotherapy: Newer Therapeutic Armamentarium against Cancer Stem Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Saurabh Pratap Singh ◽  
Richa Singh ◽  
Om Prakash Gupta ◽  
Shalini Gupta ◽  
Madan Lal Brahma Bhatt

Mounting evidence from the literature suggests the existence of a subpopulation of cancer stem cells (CSCs) in almost all types of human cancers. These CSCs possessing a self-renewal capacity inhabit primary tumors and are more defiant to standard antimitotic and molecularly targeted therapies which are used for eliminating actively proliferating and differentiated cancer cells. Clinical relevance of CSCs emerges from the fact that they are the root cause of therapy resistance, relapse, and metastasis. Earlier, surgery, chemotherapy, and radiotherapy were established as cancer treatment modalities, but recently, immunotherapy is also gaining importance in the management of various cancer patients, mostly those of the advanced stage. This review abridges potential off-target effects of inhibiting CSC self-renewal pathways on immune cells and some recent immunological studies specifically targeting CSCs on the basis of their antigen expression profile, even though molecular markers or antigens that have been described till date as expressed by cancer stem cells are not specifically expressed by these cells which is a major limitation to target CSCs. We propose that owing to CSC stemness property to mediate immunotherapy response, we can apply a combination therapy approach by targeting CSCs and tumor microenvironment (TME) along with conventional treatment strategies as an effective means to eradicate cancer cells.

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1896 ◽  
Author(s):  
Kevin Dzobo ◽  
Dimakatso Alice Senthebane ◽  
Chelene Ganz ◽  
Nicholas Ekow Thomford ◽  
Ambroise Wonkam ◽  
...  

Despite great strides being achieved in improving cancer patients’ outcomes through better therapies and combinatorial treatment, several hurdles still remain due to therapy resistance, cancer recurrence and metastasis. Drug resistance culminating in relapse continues to be associated with fatal disease. The cancer stem cell theory posits that tumors are driven by specialized cancer cells called cancer stem cells (CSCs). CSCs are a subpopulation of cancer cells known to be resistant to therapy and cause metastasis. Whilst the debate on whether CSCs are the origins of the primary tumor rages on, CSCs have been further characterized in many cancers with data illustrating that CSCs display great abilities to self-renew, resist therapies due to enhanced epithelial to mesenchymal (EMT) properties, enhanced expression of ATP-binding cassette (ABC) membrane transporters, activation of several survival signaling pathways and increased immune evasion as well as DNA repair mechanisms. CSCs also display great heterogeneity with the consequential lack of specific CSC markers presenting a great challenge to their targeting. In this updated review we revisit CSCs within the tumor microenvironment (TME) and present novel treatment strategies targeting CSCs. These promising strategies include targeting CSCs-specific properties using small molecule inhibitors, immunotherapy, microRNA mediated inhibitors, epigenetic methods as well as targeting CSC niche-microenvironmental factors and differentiation. Lastly, we present recent clinical trials undertaken to try to turn the tide against cancer by targeting CSC-associated drug resistance and metastasis.


Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1450 ◽  
Author(s):  
Patrick Santos ◽  
Fausto Almeida

Tumor microenvironment (TME) is composed of different cellular populations, such as stromal, immune, endothelial, and cancer stem cells. TME represents a key factor for tumor heterogeneity maintenance, tumor progression, and drug resistance. The transport of molecules via extracellular vesicles emerged as a key messenger in intercellular communication in the TME. Exosomes are small double-layered lipid extracellular vesicles that can carry a variety of molecules, including proteins, lipids, and nucleic acids. Exosomal miRNA released by cancer cells can mediate phenotypical changes in the cells of TME to promote tumor growth and therapy resistance, for example, fibroblast- and macrophages-induced differentiation. Cancer stem cells can transfer and enhance drug resistance in neighboring sensitive cancer cells by releasing exosomal miRNAs that target antiapoptotic and immune-suppressive pathways. Exosomes induce drug resistance by carrying ABC transporters, which export chemotherapeutic agents out of the recipient cells, thereby reducing the drug concentration to suboptimal levels. Exosome biogenesis inhibitors represent a promising adjunct therapeutic approach in cancer therapy to avoid the acquisition of a resistant phenotype. In conclusion, exosomal miRNAs play a crucial role in the TME to confer drug resistance and survivability to tumor cells, and we also highlight the need for further investigations in this promising field.


Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 633 ◽  
Author(s):  
Ana Čipak Gašparović ◽  
Lidija Milković ◽  
Nadia Dandachi ◽  
Stefanie Stanzer ◽  
Iskra Pezdirc ◽  
...  

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.


2019 ◽  
Author(s):  
FanPing Wang ◽  
Jiateng Zhong ◽  
Shanshan Wang ◽  
Caijuan Qiao ◽  
Xiangyang Li ◽  
...  

Abstract Background: Sulforaphane (SFN), an active compound in cruciferous vegetables has been characterized for its antiproliferative capacity. We investigated the role and molecular mechanism through which SFN regulates proliferation and self-renewal of lung cancer stem cells. Methods: Lung cancer stem cells (CD133-positive cells) were isolated by MACs and then measured by flow cytometry. The ability of cell proliferation was assessed by MTT assays and tumorsphere formation assays. The expressions of Sonic Hedgehog (Shh), Smoothened (Smo), Gli1 and Human Polyhomeotic Homolog 3 (PHC3) in cells were measured by quantitative reverse transcription polymerase chain reaction (qPCR) and western blot assays. The expression of transcription factor SOX2 in lung cancer stem cells was also determined by western blot assay. Shh was knocked down by siRNA to further study the role of SFN and Shh signaling pathways in lung cancer. Results: SFN inhibited the proliferation of lung cancer cells and lung cancer stem cells simultaneously. Meanwhile, we observed that Sonic Hedgehog (SHH) signaling pathway, SOX2 and Polyhomeotic Homolog 3 (PHC3) were highly activated in lung cancer stem cells. Knock-down of Shh led to reduced H460 and A549 cells proliferation. Furthermore, we observed that SFN inhibited the activity of PHC3 and SHH signaling pathways in the lung cancer stem cells. In addition, SFN combined with Knock-down of Shh gene showed a greater effect on the proliferation of lung cancer cells. Conclusion: SFN is an effective new drug which can inhibit proliferation of lung cancer stem cells through the modulation of PHC3 and SHH signaling pathways. It provides a novel target for improving therapeutic efficacy for lung cancer stem cells.


2019 ◽  
Vol 1 (Supplement_1) ◽  
pp. i3-i3
Author(s):  
Sherona Sirkisoon ◽  
Richard Carpenter ◽  
Tadas Rimkus ◽  
Daniel Doheny ◽  
Dongqin Zhu ◽  
...  

Abstract Breast cancer is the second leading cause of brain metastases in women; patients with breast cancer brain metastasis (BCBM) survive only 6–18 months after diagnosis. Mechanisms for BCBM remain unclear, which contributes to ineffective treatments and dismal prognosis. Truncated glioma-associated oncogene homolog 1 (tGLI1) belongs to the GLI1 family of zinc-finger transcription factors and functions as a tumor-specific gain-of-function mediator of tumor invasion and angiogenesis. Whether tGLI1 plays any role in metastasis of any tumor type remains unknown. Using an experimental metastasis mouse model, via intracardiac implantation, we showed that ectopic expression of tGLI1, but not GLI1, promoted preferential metastasis to brain. Conversely, selective tGLI1 knockdown using tGLI1-specific antisense oligonucleotides led to decreased brain metastasis of intracardially inoculated breast cancer cells. Furthermore, intracranial implantation mouse study revealed tGLI1 enhanced intracranial colonization and growth of breast cancer cells. Immunohistochemical staining of patient samples showed that tGLI1, but not GLI1, was increased in lymph node metastases compared to matched primary tumors, and that tGLI1 was expressed at higher levels in BCBM specimens compared to primary tumors. Whether tGLI1 plays any role in radioresistance is unknown; we found radioresistant BCBM cell lines and patient specimens expressed higher levels of tGLI1 than radiosensitive counterparts, and that tGLI1 promotes radioresistance. Since cancer stem cells (CSCs) are highly metastatic and radioresistant, we examined whether tGLI1 promotes BCBM and radioresistance through activating CSCs. Results showed that tGLI1 transcriptionally activates stemness genes CD44, Nanog, Sox2, and OCT4, leading to stem cell activation. Furthermore, we observed that tGLI1-positive CSCs strongly activated and interacted with astrocytes, the most abundant brain tumor microenvironmental cells known to promote tumor growth, in vitro and in vivo. Collectively, our findings establish a novel role of that tGLI1 plays in promoting breast cancer preferential metastasis to brain, radioresistance, and astrocytes in the metastatic niche.


2019 ◽  
Vol 79 (16) ◽  
pp. 4015-4025 ◽  
Author(s):  
Bikul Das ◽  
Bidisha Pal ◽  
Rashmi Bhuyan ◽  
Hong Li ◽  
Anupam Sarma ◽  
...  

2021 ◽  
Vol 14 (1) ◽  
pp. 60
Author(s):  
Laura Sofia Carvalho ◽  
Nélio Gonçalves ◽  
Nuno André Fonseca ◽  
João Nuno Moreira

Cancer, one of the most mortal diseases worldwide, is characterized by the gain of specific features and cellular heterogeneity. Clonal evolution is an established theory to explain heterogeneity, but the discovery of cancer stem cells expanded the concept to include the hierarchical growth and plasticity of cancer cells. The activation of epithelial-to-mesenchymal transition and its molecular players are widely correlated with the presence of cancer stem cells in tumors. Moreover, the acquisition of certain oncological features may be partially attributed to alterations in the levels, location or function of nucleolin, a multifunctional protein involved in several cellular processes. This review aims at integrating the established hallmarks of cancer with the plasticity of cancer cells as an emerging hallmark; responsible for tumor heterogeneity; therapy resistance and relapse. The discussion will contextualize the involvement of nucleolin in the establishment of cancer hallmarks and its application as a marker protein for targeted anticancer therapies


2022 ◽  
Vol 23 (2) ◽  
pp. 625
Author(s):  
Jacopo Meldolesi

Stem cells, identified several decades ago, started to attract interest at the end of the nineties when families of mesenchymal stem cells (MSCs), concentrated in the stroma of most organs, were found to participate in the therapy of many diseases. In cancer, however, stem cells of high importance are specific to another family, the cancer stem cells (CSCs). This comprehensive review is focused on the role and the mechanisms of CSCs and of their specific extracellular vesicles (EVs), which are composed of both exosomes and ectosomes. Compared to non-stem (normal) cancer cells, CSCs exist in small populations that are preferentially distributed to the niches, such as minor specific tissue sites corresponding to the stroma of non-cancer tissues. At niches and marginal sites of other cancer masses, the tissue exhibits peculiar properties that are typical of the tumor microenvironment (TME) of cancers. The extracellular matrix (ECM) includes components different from non-cancer tissues. CSCs and their EVs, in addition to effects analogous to those of MSCs/EVs, participate in processes of key importance, specific to cancer: generation of distinct cell subtypes, proliferation, differentiation, progression, formation of metastases, immune and therapy resistance, cancer relapse. Many of these, and other, effects require CSC cooperation with surrounding cells, especially MSCs. Filtered non-cancer cells, especially macrophages and fibroblasts, contribute to collaborative cancer transition/integration processes. Therapy developments are mentioned as ongoing preclinical initiatives. The preliminary state of clinical medicine is presented in terms of both industrial development and future treatments. The latter will be administered to specific patients together with known drugs, with the aim of eradicating their tumor growth and metastases.


Author(s):  
Sarthak Sahoo ◽  
Atchuta Srinivas Duddu ◽  
Adrian Biddle ◽  
Mohit Kumar Jolly

Establishing macrometastases at distant organs is a highly challenging process for cancer cells, with extremely high attrition rates. A very small percentage of disseminated cells have the ability to dynamically adapt to their changing micro-environments through reversibly switching to another phenotype, aiding metastasis. Such plasticity can be exhibited along one or more axes – epithelial-mesenchymal plasticity (EMP) and cancer stem cells (CSCs) being the two most studied, and often tacitly assumed to be synonymous. Here, we review the emerging concepts related to EMP and CSCs across multiple cancers. Both processes are multi-dimensional in nature; for instance, EMP can be defined on morphological, molecular and functional changes, which may or may not be synchronized. Similarly, self-renewal, multi-lineage potential, and anoikis and/or therapy resistance may not all occur simultaneously in CSCs. Thus, arriving at rigorous functional definitions for both EMP and CSCs is crucial. These processes are dynamic, reversible, and semi-independent in nature; cells traverse the inter-connected high-dimensional EMP and CSC landscapes in diverse paths, each of which may exhibit a distinct EMP-CSC coupling. Our proposed model offers a potential unifying framework for elucidating the coupled decision-making along these dimensions and highlights a key set of open questions to be answered.


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fanping Wang ◽  
Yanwei Sun ◽  
Xiaoyu Huang ◽  
Caijuan Qiao ◽  
Wenrui Zhang ◽  
...  

AbstractSulforaphane (SFN), an active compound in cruciferous vegetables, has been characterized by its antiproliferative capacity. We investigated the role and molecular mechanism through which SFN regulates proliferation and self-renewal of lung cancer stem cells. CD133+ cells were isolated with MACs from lung cancer A549 and H460 cells. In this study, we found that SFN inhibited the proliferation of lung cancer cells and self-renewal of lung cancer stem cells simultaneously. Meanwhile, the mRNA and protein expressions of Shh, Smo, Gli1 and PHC3 were highly activated in CD133+ lung cancer cells. Compared with siRNA-control group, Knock-down of Shh inhibited proliferation of CD133+ lung cancer cells, and decreased the protein expression of PHC3 in CD133+ lung cancer cells. Knock-down of PHC3 also affected the proliferation and decreased the Shh expression level in CD133+ lung cancer cells. In addition, SFN inhibited the activities of Shh, Smo, Gli1 and PHC3 in CD133+ lung cancer cells. Furthermore, the inhibitory effect of SFN on the proliferation of siRNA-Shh and siRNA-PHC3 cells was weaker than that on the proliferation of siRNA-control cells. Sonic Hedgehog signaling pathway might undergo a cross-talk with PHC3 in self-renewal of lung cancer stem cells. SFN might be an effective new drug which could inhibit self-renewal of lung cancer stem cells through the modulation of Sonic Hedgehog signaling pathways and PHC3. This study could provide a novel way to improve therapeutic efficacy for lung cancer stem cells.


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