CD133 as a regulator of cancer metastasis through the cancer stem cells

Exploring Importance and Regulation of Autophagy in Cancer Stem Cells and Stem Cell-Based Therapies

Autophagy is a globally conserved cellular activity that plays a critical role in maintaining cellular homeostasis through the breakdown and recycling of cellular constituents. In recent years, there has been much emphasis given to its complex role in cancer stem cells (CSCs) and stem cell treatment. This study examines the molecular processes that support autophagy and how it is regulated in the context of CSCs and stem cell treatment. Although autophagy plays a dual role in the management of CSCs, affecting their removal as well as their maintenance, the intricate interaction between the several signaling channels that control cellular survival and death as part of the molecular mechanism of autophagy has not been well elucidated. Given that CSCs have a role in the development, progression, and resistance to treatment of tumors, it is imperative to comprehend their biological activities. CSCs are important for cancer biology because they also show a tissue regeneration model that helps with organoid regeneration. In other words, the manipulation of autophagy is a viable therapeutic approach in the treatment of cancer and stem cell therapy. Both synthetic and natural substances that target autophagy pathways have demonstrated promise in improving stem cell-based therapies and eliminating CSCs. Nevertheless, there are difficulties associated with the limitations of autophagy in CSC regulation, including resistance mechanisms and off-target effects. Thus, the regulation of autophagy offers a versatile strategy for focusing on CSCs and enhancing the results of stem cell therapy. Therefore, understanding the complex interactions between autophagy and CSC biology would be essential for creating therapeutic treatments that work in both regenerative medicine and cancer treatment.

Seedless black Vitis vinifera polyphenols suppress hepatocellular carcinoma in vitro and in vivo by targeting apoptosis, cancer stem cells, and proliferation

Hepatocellular carcinoma (HCC) is an aggressive tumor and one of the most challenging cancers to treat. Here, we evaluated the in vitro and in vivo ameliorating impacts of seedless black Vitis vinifera (VV) polyphenols on HCC. Following the preparation of the VV crude extract (VVCE) from seedless VV (pulp and skin), three fractions (VVF1, VVF2, and VVF3) were prepared. The anticancer potencies of the prepared fractions, compared to 5-FU, were assessed against HepG2 and Huh7 cells. In addition, the effects of these fractions on p-dimethylaminoazobenzene-induced HCC in mice were evaluated. The predicted impacts of selected phenolic constituents of VV fractions on the activity of essential HCC-associated enzymes (NADPH oxidase "NADPH-NOX2", histone deacetylase 1 "HDAC1", and sepiapterin reductase "SepR") were analyzed using molecular docking. The results showed that VVCE and its fractions induced apoptosis and collapsed CD133+ stem cells in the studied cancer cell lines with an efficiency greater than 5-FU. VVF1 and VVF2 exhibited the most effective anticancer fractions in vitro; therefore, we evaluated their influences in mice. VVF1 and VVF2 improved liver morphology and function, induced apoptosis, and lowered the fold expression of various crucial genes that regulate cancer stem cells and other vital pathways for HCC progression. For most of the examined parameters, VVF1 and VVF2 had higher potency than 5-FU, and VVF1 showed more efficiency than VVF2. The selected phenolic compounds displayed competitive inhibitory action on NADPH-NOX2, HDAC1, and SepR. In conclusion, these findings declare that VV polyphenolic fractions, particularly VVF1, could be promising safe anti-HCC agents.

Influence of Aldehyde Dehydrogenase Inhibition on Stemness of Endometrial Cancer Stem Cells

Endometrial cancer is one of the most common gynaecological malignancies. Although often diagnosed at an early stage, there is a subset of patients with recurrent and metastatic disease for whom current treatments are not effective. Cancer stem cells (CSCs) play a pivotal role in triggering tumorigenesis, disease progression, recurrence, and metastasis, as high aldehyde dehydrogenase (ALDH) activity is associated with invasiveness and chemotherapy resistance. Therefore, this study aimed to evaluate the effects of ALDH inhibition in endometrial CSCs. ECC-1 and RL95-2 cells were submitted to a sphere-forming protocol to obtain endometrial CSCs. ALDH inhibition was evaluated through ALDH activity and expression, sphere-forming capacity, self-renewal, projection area, and CD133, CD44, CD24, and P53 expression. A mass spectrometry-based proteomic study was performed to determine the proteomic profile of endometrial cancer cells upon N,N-diethylaminobenzaldehyde (DEAB). DEAB reduced ALDH activity and expression, along with a significant decrease in sphere-forming capacity and projection area, with increased CD133 expression. Additionally, DEAB modulated P53 expression. Endometrial cancer cells display a distinct proteomic profile upon DEAB, sharing 75 up-regulated and 30 down-regulated proteins. In conclusion, DEAB inhibits ALDH activity and expression, influencing endometrial CSC phenotype. Furthermore, ALDH18A1, SdhA, and UBAP2L should be explored as novel molecular targets for endometrial cancer.

Effects of reprogrammed splenic CD8+ T-cells in vitro and in mice with spontaneous metastatic Lewis lung carcinoma

BACKGROUND

Metastatic disease is a major and difficult-to-treat complication of lung cancer. Considering insufficient effectiveness of existing therapies and taking into account the current problem of lung cancer chemoresistance, it is necessary to continue the development of new treatments.

METHODS

Previously, we have demonstrated the antitumor effects of reprogrammed CD8+ T-cells (rCD8+ T-cells) from the spleen in mice with orthotopic lung carcinoma. Reprogramming was conducted by inhibiting the MAPK/ERK signalling pathway through MEKi and the immune checkpoint PD-1/PD-L1. Concurrently, CD8+ T-cells were trained in Lewis lung carcinoma (LLC) cells. We suggested that rCD8+ T-cells isolated from the spleen might impede the development of metastatic disease.

RESULTS

The present study has indicated that the reprogramming procedure enhances the survival and cytotoxicity of splenic CD8+ T-cells in LLC culture. In an LLC model of spontaneous metastasis, splenic rCD8 + T-cell therapy augmented the numbers of CD8+ T-cells and CD4+ T-cells in the lungs of mice. These changes can account for the partial reduction of tumors in the lungs and the mitigation of metastatic activity.

CONCLUSIONS

Our proposed reprogramming method enhances the antitumor activity of CD8+ T-cells isolated from the spleen and could be valuable in formulating an approach to treating metastatic disease in patients with lung cancer.

Emerging roles of prominin-1 (CD133) in the dynamics of plasma membrane architecture and cell signaling pathways in health and disease

Prominin-1 (CD133) is a cholesterol-binding membrane glycoprotein selectively associated with highly curved and prominent membrane structures. It is widely recognized as an antigenic marker of stem cells and cancer stem cells and is frequently used to isolate them from biological and clinical samples. Recent progress in understanding various aspects of CD133 biology in different cell types has revealed the involvement of CD133 in the architecture and dynamics of plasma membrane protrusions, such as microvilli and cilia, including the release of extracellular vesicles, as well as in various signaling pathways, which may be regulated in part by posttranslational modifications of CD133 and its interactions with a variety of proteins and lipids. Hence, CD133 appears to be a master regulator of cell signaling as its engagement in PI3K/Akt, Src-FAK, Wnt/β-catenin, TGF-β/Smad and MAPK/ERK pathways may explain its broad action in many cellular processes, including cell proliferation, differentiation, and migration or intercellular communication. Here, we summarize early studies on CD133, as they are essential to grasp its novel features, and describe recent evidence demonstrating that this unique molecule is involved in membrane dynamics and molecular signaling that affects various facets of tissue homeostasis and cancer development. We hope this review will provide an informative resource for future efforts to elucidate the details of CD133's molecular function in health and disease.

Shrimp Lipids Inhibit Migration, Epithelial-Mesenchymal Transition, and Cancer Stem Cells via Akt/mTOR/c-Myc Pathway Suppression

Shrimp is a rich source of bioactive molecules that provide health benefits. However, the high cholesterol content in shrimp oil may pose a risk. We utilized the cholesterol elimination method to obtain cholesterol-free shrimp lipids (CLs) and investigated their anticancer potential, focusing on cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT). Our study focused on CSCs and EMT, as these factors are known to contribute to cancer metastasis. The results showed that treatment with CLs at doses ranging from 0 to 500 µg/mL significantly suppressed the cell migration ability of human lung cancer (H460 and H292) cells, indicating its potential to inhibit cancer metastasis. The CLs at such concentrations did not cause cytotoxicity to normal human keratinocytes. Additionally, CL treatment was found to significantly reduce the levels of Snail, Slug, and Vimentin, which are markers of EMT. Furthermore, we investigated the effect of CLs on CSC-like phenotypes and found that CLs could significantly suppress the formation of a three-dimensional (3D) tumor spheroid in lung cancer cells. Furthermore, CLs induced apoptosis in the CSC-rich population and significantly depleted the levels of CSC markers CD133, CD44, and Sox2. A mechanistic investigation demonstrated that exposing lung cancer cells to CLs downregulated the phosphorylation of Akt and mTOR, as well as c-Myc expression. Based on these findings, we believe that CLs may have beneficial effects on health as they potentially suppress EMT and CSCs, as well as the cancer-potentiating pathway of Akt/mTOR/c-Myc.

Advances in the role of GPX3 in ovarian cancer (Review)

Ovarian cancer (OC) is the 5th most common malignancy in women, and the leading cause of death from gynecologic malignancies. Owing to tumor heterogeneity, lack of reliable early diagnostic methods and high incidence of chemotherapy resistance, the 5‑year survival rate of patients with advanced OC remains low despite considerable advances in detection and therapeutic approaches. Therefore, identifying novel therapeutic targets to improve the prognosis of patients with OC is crucial. The expression of glutathione peroxidase 3 (GPX3) plays a crucial role in the growth, proliferation and differentiation of various malignant tumors. In OC, GPX3 is the only antioxidant enzyme the high expression of which is negatively correlated with the overall survival of patients. GPX3 may affect lipid metabolism in tumor stem cells by influencing redox homeostasis in the tumor microenvironment. The maintenance of stemness in OC stem cells (OCSCs) is strongly associated with poor prognosis and recurrence in patients. The aim of the present study was to review the role of GPX3 in OC and investigate the potential factors and effects of GPX3 on OCSCs. The findings of the current study offer novel potential targets for drug therapy in OC, enhance the theoretical foundation of OC drug therapy and provide valuable references for clinical treatment.

Identification of a cryptic functional apolipophorin-III domain within the Prominin-1 gene of Litopenaeus vannamei

The Apolipophorin-III (apoLp-III) is reported as an essential protein element in lipids transport and incorporation in lepidopterans. Structurally, apoLp-III has an α-helix bundle structure composed of five α-helices. Interestingly, classic studies proposed a structural switch triggered by its interaction with lipids, where the α-helix bundle opens. Currently, the study of the apoLp-III has been limited to insects, with no homologs identified in other arthropods. By implementing a structure-based search with the Phyre2 algorithm surveying the shrimp Litopenaeus vannamei's transcriptome, we identified a putative apoLp-III in this farmed penaeid (LvApoLp-III). Unlike canonical apoLp-III, the LvApoLp-III was identified as an internal domain within the transmembrane protein Prominin-1. Structural modeling using the template-based Phyre2 and template-free AlphaFold algorithms rendered two distinct structural topologies: the α-helix bundle and a coiled-coil structure. Notably, the secondary structure composition on both models was alike, with differences in the orientation and distribution of the α-helices and hydrophobic moieties. Both models provide insights into the classical structural switch induced by lipids in apoLp-III. To corroborate structure/function inferences, we cloned the synthetic LvApoLp-III domain, overexpressed, and purified the recombinant protein. Circular dichroism measurements with the recombinant LvApoLp-III agreed with the structural models. In vitro liposome interaction demonstrated that the apoLp-III domain within the PROM1 of L.vannamei associated similarly to exchangeable apolipoproteins. Altogether, this work reports the presence of an apolipophorin-III domain in crustaceans for the first time and opens questions regarding its function and importance in lipid metabolism or the immune system.

Mechanisms of Melanoma Progression and Treatment Resistance: Role of Cancer Stem-like Cells

Melanoma is the third most common type of skin cancer, characterized by its heterogeneity and propensity to metastasize to distant organs. Melanoma is a heterogeneous tumor, composed of genetically divergent subpopulations, including a small fraction of melanoma-initiating cancer stem-like cells (CSCs) and many non-cancer stem cells (non-CSCs). CSCs are characterized by their unique surface proteins associated with aberrant signaling pathways with a causal or consequential relationship with tumor progression, drug resistance, and recurrence. Melanomas also harbor significant alterations in functional genes (BRAF, CDKN2A, NRAS, TP53, and NF1). Of these, the most common are the BRAF and NRAS oncogenes, with 50% of melanomas demonstrating the BRAF mutation (BRAFV600E). While the successful targeting of BRAFV600E does improve overall survival, the long-term efficacy of available therapeutic options is limited due to adverse side effects and reduced clinical efficacy. Additionally, drug resistance develops rapidly via mechanisms involving fast feedback re-activation of MAPK signaling pathways. This article updates information relevant to the mechanisms of melanoma progression and resistance and particularly the mechanistic role of CSCs in melanoma progression, drug resistance, and recurrence.

CD133, CD47, and PD-L1 Expression in Ovarian High-grade Serous Carcinoma and Its Association with Metastatic Disease: A Cross-sectional Study

INTRODUCTION

Ovarian cancer is a primary cause of cancer-related death in women. At the time of diagnosis, the majority of ovarian malignancies had metastasized. It is believed that cancer stem cells (CSCs) and immune evasion play a crucial role in the metastatic process. The objective of this study was to describe the expression profiles of cluster of differentiation (CD)133, CD47, and programmed death ligand 1 (PD-L1) in high-grade serous ovarian cancer (HGSC) as commonly utilized markers for CSCs and immune evasion.

MATERIAL AND METHODS

Using an immunohistochemical procedure, 51 HGSC tissue samples were stained with anti-CD133, anti-CD47, and anti-PDL1 antibodies. The samples contained 31 HGSC with metastases and 20 HGSC absent metastases. The expression of CD133, CD47, and PD-L1 was compared between groups.

RESULTS

Strong expression of CD133 and CD47 was seen in 52% and 66% of tissue samples, respectively. Twenty of the thirty-one patients with metastases had a significant level of CD133 expression, with a p-value of 0.039. CD47 expression was increased in 26 of 31 samples with metastatic disease. A 62.7 percent of samples were negative for PD-L1 expression, significantly inversely correlated with HGSC metastatic disease (p=0.023). Although there was no significant association between CD133, CD47, or PD-L1 expression and age, Tumor Infiltrating Lymphocytes demonstrated a significantly varied relationship.

CONCLUSION

Our findings suggested that expression of CD133, CD47, and PD-L1 may have dynamically increased as the primary lesion progressed to the metastatic lesion, implying that these proteins may be involved in the progression of high-grade serous ovarian cancer from the primary to the metastatic stage.

Biomarkers and targeted therapy for cancer stem cells

Cancer stem cells (CSCs) are a small subpopulation of cancer cells with capabilities of self-renewal, differentiation, and tumorigenicity, and play a critical role in driving tumor heterogeneity that evolves insensitivity to therapeutics. For these reasons, extensive efforts have been made to identify and target CSCs to potentially improve the antitumor efficacy of therapeutics. While progress has been made to uncover certain CSC-associated biomarkers, the identification of CSC-specific markers, especially the targetable ones, remains a significant challenge. Here we provide an overview of the unique signaling and metabolic pathways of CSCs, summarize existing CSC biomarkers and CSC-targeted therapies, and discuss strategies to further differentiate CSCs from non-stem cancer cells and healthy cells for the development of enhanced CSC-targeted therapies.

Colibactin-producing Escherichia coli enhance resistance to chemotherapeutic drugs by promoting epithelial to mesenchymal transition and cancer stem cell emergence

Human colorectal cancers (CRCs) are readily colonized by colibactin-producing E. coli (CoPEC). CoPEC induces DNA double-strand breaks, DNA mutations, genomic instability, and cellular senescence. Infected cells produce a senescence-associated secretory phenotype (SASP), which is involved in the increase in tumorigenesis observed in CRC mouse models infected with CoPEC. This study investigated whether CoPEC, and the SASP derived from CoPEC-infected cells, impacted chemotherapeutic resistance. Human intestinal epithelial cells were infected with the CoPEC clinical 11G5 strain or with its isogenic mutant, which is unable to produce colibactin. Chemotherapeutic resistance was assessed in vitro and in a xenograft mouse model. Expressions of cancer stem cell (CSC) markers in infected cells were investigated. Data were validated using a CRC mouse model and human clinical samples. Both 11G5-infected cells, and uninfected cells incubated with the SASP produced by 11G5-infected cells exhibited an increased resistance to chemotherapeutic drugs in vitro and in vivo. This finding correlated with the induction of the epithelial to mesenchymal transition (EMT), which led to the emergence of cells exhibiting CSC features. They grew on ultra-low attachment plates, formed colonies in soft agar, and overexpressed several CSC markers (e.g. CD133, OCT-3/4, and NANOG). In agreement with these results, murine and human CRC biopsies colonized with CoPEC exhibited higher expression levels of OCT-3/4 and NANOG than biopsies devoid of CoPEC. Conclusion: CoPEC might aggravate CRCs by inducing the emergence of cancer stem cells that are highly resistant to chemotherapy.

The role of hypoxia and radiation in developing a CTCs-like phenotype in murine osteosarcoma cells

Introduction: Cancer treatment has evolved significantly, yet concerns about tumor recurrence and metastasis persist. Within the dynamic tumor microenvironment, a subpopulation of mesenchymal tumor cells, known as Circulating Cancer Stem Cells (CCSCs), express markers like CD133, TrkB, and CD47, making them radioresistant and pivotal to metastasis. Hypoxia intensifies their stemness, complicating their identification in the bloodstream. This study investigates the interplay of acute and chronic hypoxia and radiation exposure in selecting and characterizing cells with a CCSC-like phenotype. Methods: LM8 murine osteosarcoma cells were cultured and subjected to normoxic (21% O2) and hypoxic (1% O2) conditions. We employed Sphere Formation and Migration Assays, Western Blot analysis, CD133 Cell Sorting, and CD133+ Fluorescent Activated Cell Sorting (FACS) analysis with a focus on TrkB antibody to assess the effects of acute and chronic hypoxia, along with radiation exposure. Results: Our findings demonstrate that the combination of radiation and acute hypoxia enhances stemness, while chronic hypoxia imparts a cancer stem-like phenotype in murine osteosarcoma cells, marked by increased migration and upregulation of CCSC markers, particularly TrkB and CD47. These insights offer a comprehensive understanding of the interactions between radiation, hypoxia, and cellular responses in the context of cancer treatment. Discussion: This study elucidates the complex interplay among radiation, hypoxia, and cellular responses, offering valuable insights into the intricacies and potential advancements in cancer treatment.

Hsa_circRNA_001676 accelerates the proliferation, migration and stemness in colorectal cancer through regulating miR-556-3p/G3BP2 axis

Circular RNAs (circRNAs) play key roles in colorectal cancer (CRC) progression, but little is known about the biological functions of hsa_circRNA_001676 in CRC. Therefore, we explored the potential role of hsa_circRNA_001676 in CRC development. RT-qPCR was performed to determine hsa_circRNA_001676, miR-556-3p and Ras-GTPase-activating SH3 domain-binding-proteins 2 (G3BP2) levels in CRC tissues. Meanwhile, to evaluate the roles of hsa_circRNA_001676, miR-556-3p and G3BP2 on CRC, functional analysis of cell proliferation, migration and stemness were then performed. Our results showed that compared to normal tissues, hsa_circRNA_001676 and G3BP2 level was elevated, but miR-556-3p level was reduced in CRC tissues. Additionally, luciferase reporter results showed that hsa_circRNA_001676 was shown to target miR-556-3p, and G3BP2 was targeted by miR-556-3p. Hsa_circRNA_001676 or G3BP2 overexpression promoted CRC cell proliferation and migration. Conversely, miR-556-3p overexpression suppressed CRC cell proliferation and migration. Moreover, deficiency of hsa_circRNA_001676 or G3BP2 repressed the CRC cell proliferation, migration and stemness. Meanwhile, hsa_circRNA_001676 deficiency obviously reduced tumor growth and stemness in a CRC mouse xenograft model. Furthermore, hsa_circRNA_001676 deficiency notably reduced G3BP2 level, but elevated miR-556-3p level in tumor tissues from tumor-bearing mice. Mechanistically, hsa_circRNA_001676 targeted miR-556-3p to increase G3BP2 level, contributing to the progression of CRC. Collectively, hsa_circRNA_001676 was able to accelerate proliferation, migration and stemness in CRC through regulating miR-556-3p/G3BP2 axis, suggesting that hsa_circRNA_001676 may become a potential therapeutic target in treating CRC.

APEX1 predicts poor prognosis of gallbladder cancer and affects biological properties of CD133+ GBC-SD cells via upregulating Jagged1

Although APEX1 is associated with the tumorigenesis and progression of some human cancer types, the function of APEX1 in gallbladder cancer (GBC) is unclear. In this study, we found that APEX1 expression is up-regulated in GBC tissues, and APEX1 positive expression is related to aggressive clinicopathological features and poor prognosis of GBC. APEX1 was an independent risk factor of GBC prognosis, and presented some pathological diagnostic significance in GBC. Furthermore, APEX1 was overexpressed in CD133⁺ GBC-SD cells in comparison with GBC-SD cells. APEX1 knockdown increased the sensitivity of CD133⁺ GBC-SD cells to 5-Fluorouracil via facilitating cell necrosis and apoptosis. APEX1 knockdown in CD133⁺ GBC-SD cells dramatically inhibited cell proliferation, migration, and invasion, and promoted cell apoptosis in vitro. APEX1 knockdown in CD133⁺ GBC-SD cells accelerated tumor growth in the xenograft models. Mechanistically, APEX1 affected these malignant properties via upregulating Jagged1 in CD133⁺ GBC-SD cells. Thus, APEX1 is a promising prognostic biomarker, and a potential therapeutic target for GBC.

Cancer Stem Cells in Pancreatic Ductal Adenocarcinoma

The first discovery of cancer stem cells (CSCs) in leukaemia triggered active research on stemness in neoplastic tissues. CSCs represent a subpopulation of malignant cells, defined by unique properties: a dedifferentiated state, self-renewal, pluripotency, an inherent resistance to chemo- and radiotherapy, the presence of certain epigenetic alterations, as well as a higher tumorigenicity in comparison with the general population of cancer cells. A combination of these features highlights CSCs as a high-priority target during cancer treatment. The presence of CSCs has been confirmed in multiple malignancies, including pancreatic ductal adenocarcinoma, an entity that is well known for its dismal prognosis. As the aggressive course of pancreatic carcinoma is partly attributable to treatment resistance, CSCs could contribute to adverse outcomes. The aim of this review is to summarize the current information regarding the markers and molecular features of CSCs in pancreatic ductal adenocarcinoma and the therapeutic options to remove them.

Treatment with decitabine induces the expression of stemness markers, PD-L1 and NY-ESO-1 in colorectal cancer: potential for combined chemoimmunotherapy

BACKGROUND

The mechanism of tumor immune escape and progression in colorectal cancer (CRC) is widely investigated in-vitro to help understand and identify agents that might play a crucial role in response to treatment and improve the overall survival of CRC patients. Several mechanisms of immune escape and tumor progression, including expression of stemness markers, inactivation of immunoregulatory genes by methylation, and epigenetic silencing, have been reported in CRC, indicating the potential of demethylating agents as anti-cancer drugs. Of these, a chemotherapeutic demethylating agent, Decitabine (DAC), has been reported to induce a dual effect on both DNA demethylation and histone changes leading to an increased expression of target biomarkers, thus making it an attractive anti-tumorigenic drug.

METHODS

We compared the effect of DAC in primary 1076 Col and metastatic 1872 Col cell lines isolated and generated from patients' tumor tissues. Both cell lines were treated with DAC, and the expression of the NY-ESO-1 cancer-testis antigen, the PD-L1 immunoinhibitory marker, and the CD44, Nanog, KLF-4, CD133, MSI-1 stemness markers were analyzed using different molecular and immunological assays.

RESULTS

DAC treatment significantly upregulated stemness markers in both primary 1076 Col and meta-static 1872 Col cell lines, although a lower effect occurred on the latter: CD44 (7.85 fold; ***p = 0.0001 vs. (4.19 fold; *p = 0.0120), Nanog (4.1 fold; ***p < 0.0001 vs.1.69 fold; ***p = 0.0008), KLF-4 (4.33 fold; ***p < 0.0001 vs.2.48 fold; ***p = 0.0005), CD133 (16.77 fold; ***p = 0.0003 vs.6.36 fold; *p = 0.0166), and MSI-1 (2.33 fold; ***p = 0.0003 vs.2.3 fold; ***p = 0.0004), respectively. Interestingly, in the metastatic 1872 Col cells treated with DAC, the expression of both PD-L1 and NY-ESO-1 was increased tenfold (*p = 0.0128) and fivefold (***p < 0.0001), respectively.

CONCLUSIONS

We conclude that the upregulation of both stemness and immune checkpoint markers by DAC treatment on CRC cells might represent a mechanism of immune evasion. In addition, induction of NY-ESO-1 may represent an immuno-therapeutic option in metastatic CRC patients. Finally, the combination of DAC and anti-PD-1/anti-PD-L1 antibodies treatment should represent a potential therapeutic intervention for this group of patients.

Biomaterial-based platforms for modulating immune components against cancer and cancer stem cells

Immunotherapy involves the therapeutic alteration of the patient's immune system to identify, target, and eliminate cancer cells. Dendritic cells, macrophages, myeloid-derived suppressor cells, and regulatory T cells make up the tumor microenvironment. In cancer, these immune components (in association with some non-immune cell populations like cancer-associated fibroblasts) are directly altered at a cellular level. By dominating immune cells with molecular cross-talk, cancer cells can proliferate unchecked. Current clinical immunotherapy strategies are limited to conventional adoptive cell therapy or immune checkpoint blockade. Targeting and modulating key immune components presents an effective opportunity. Immunostimulatory drugs are a research hotspot, but their poor pharmacokinetics, low tumor accumulation, and non-specific systemic toxicity limit their use. This review describes the cutting-edge research undertaken in the field of nanotechnology and material science to develop biomaterials-based platforms as effective immunotherapeutics. Various biomaterial types (polymer-based, lipid-based, carbon-based, cell-derived, etc.) and functionalization methodologies for modulating tumor-associated immune/non-immune cells are explored. Additionally, emphasis has been laid on discussing how these platforms can be used against cancer stem cells, a fundamental contributor to chemoresistance, tumor relapse/metastasis, and failure of immunotherapy. Overall, this comprehensive review strives to provide up-to-date information to an audience working at the juncture of biomaterials and cancer immunotherapy. STATEMENT OF SIGNIFICANCE: Cancer immunotherapy possesses incredible potential and has successfully transitioned into a clinically lucrative alternative to conventional anti-cancer therapies. With new immunotherapeutics getting rapid clinical approval, fundamental problems associated with the dynamic nature of the immune system (like limited clinical response rates and autoimmunity-related adverse effects) have remained unanswered. In this context, treatment approaches that focus on modulating the compromised immune components within the tumor microenvironment have garnered significant attention amongst the scientific community. This review aims to provide a critical discussion on how various biomaterials (polymer-based, lipid-based, carbon-based, cell-derived, etc.) can be employed along with immunostimulatory agents to design innovative platforms for selective immunotherapy directed against cancer and cancer stem cells.

Prominin-1 promotes restitution of the murine extrahepatic biliary luminal epithelium following cholestatic liver injury

BACKGROUND AND AIMS

Restitution of the extrahepatic biliary luminal epithelium in cholangiopathies is poorly understood. Prominin-1 (Prom1) is a key component of epithelial ciliary body of stem/progenitor cells. Given that intrahepatic Prom1-expressing progenitor cells undergo cholangiocyte differentiation, we hypothesized that Prom1 may promote restitution of the extrahepatic bile duct (EHBD) epithelium following injury.

APPROACH AND RESULTS

Utilizing various murine biliary injury models, we identified Prom1-expressing cells in the peribiliary glands of the EHBD. These Prom1-expressing cells are progenitor cells which give rise to cholangiocytes as part of the normal maintenance of the EHBD epithelium. Following injury, these cells proliferate significantly more rapidly to re-populate the biliary luminal epithelium. Null mutation of Prom1 leads to significantly >10-fold dilated peribiliary glands following rhesus rotavirus-mediated biliary injury. Cultured organoids derived from Prom1 knockout mice are comprised of biliary progenitor cells with altered apical-basal cellular polarity, significantly fewer and shorter cilia, and decreased organoid proliferation dynamics consistent with impaired cell motility.

CONCLUSIONS

We, therefore, conclude that Prom1 is involved in biliary epithelial restitution following biliary injury in part through its role in supporting cell polarity.

Tumor lysis syndrome promotes cancer chemoresistance and relapse through AMPK inhibition

Cancer is a disease caused when cells divide uncontrollably and spread into surrounding tissues. There are different therapeutic modalities that control cancer growth, of which surgery, chemotherapy, and radiotherapy. Chemotherapy is a cancer treatment approach in which medications are used to inhibit cell proliferation and tumor multiplication, thus avoiding invasion and metastasis and thus eradicate cancer. One of the common complications associated with cancer chemotherapy is rapid lysis of expanding tumor cells, known as tumor lysis syndrome (TLS). TLS is associated with number of metabolic changes such as hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia. Among the consequences of hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia is the inhibition of 5' AMP-activated protein kinase (AMPK). Inhibition of AMPK induced different cancer chemo-resistance mechanisms such as cancer stem cells (CSCs), p-glycoproteins, Octamer-binding transcription factor 4 (OCT-4), homeobox protein NANOG, Krüppel-like factor 4 (KLF4) and immune microenvironment and thus leads to poor response to chemotherapy and even relapses after treatment. Our review aims to uncover new mechanisms underlying the metabolic consequences of tumor lysis on AMPK in tumor microenvironment. In this review, we also investigated the effect of AMPK on different cancer chemo-resistance mechanisms such as cancer stem cells, p-glycoproteins, OCT-4, NANOG, KLF4 and immune microenvironment.

Cancer fitness genes: emerging therapeutic targets for metastasis

Development of cancer therapeutics has traditionally focused on targeting driver oncogenes. Such an approach is limited by toxicity to normal tissues and treatment resistance. A class of 'cancer fitness genes' with crucial roles in metastasis have been identified. Elevated or altered activities of these genes do not directly cause cancer; instead, they relieve the stresses that tumor cells encounter and help them adapt to a changing microenvironment, thus facilitating tumor progression and metastasis. Importantly, as normal cells do not experience high levels of stress under physiological conditions, targeting cancer fitness genes is less likely to cause toxicity to noncancerous tissues. Here, we summarize the key features and function of cancer fitness genes and discuss their therapeutic potential.

Overexpression of KiSS1 Induces the Proliferation of Hepatocarcinoma and Increases Metastatic Potential by Increasing Migratory Ability and Angiogenic Capacity

Liver cancer has a high prevalence, with majority of the cases presenting as hepatocellular carcinoma (HCC). The prognosis of metastatic HCC has hardly improved over the past decade, highlighting the necessity for liver cancer research. Studies have reported the ability of the KiSS1 gene to inhibit the growth or metastasis of liver cancer, but contradictory research results are also emerging. We, therefore, sought to investigate the effects of KiSS1 on growth and migration in human HCC cells. HepG2 human HCC cells were infected with lentivirus particles containing KiSS1. The overexpression of KiSS1 resulted in an increased proliferation rate of HCC cells. Quantitative polymerase chain reaction and immunoblotting revealed increased Akt activity, and downregulation of the G1/S phase cell cycle inhibitors. A significant increase in tumor spheroid formation with upregulation of β-catenin and CD133 was also observed. KiSS1 overexpression promoted the migratory, invasive ability, and metastatic capacity of the hepatocarcinoma cell line, and these effects were associated with changes in the expressions of epithelial mesenchymal transition (EMT)-related genes such as E-cadherin, N-cadherin, and slug. KiSS1 overexpression also resulted in dramatically increased tumor growth in the xenograft mouse model, and upregulation of proliferating cell nuclear antigen (PCNA) and Ki-67 in the HCC tumors. Furthermore, KiSS1 increased the angiogenic capacity by upregulation of the vascular endothelial growth factor A (VEGF-A) and CD31. Based on these observations, we infer that KiSS1 not only induces HCC proliferation, but also increases the metastatic potential by increasing the migratory ability and angiogenic capacity.

Implications of cancer stem cells in diabetes and pancreatic cancer

This review provides a detailed study of pancreatic cancer (PC) and the implication of different types of cancers concerning diabetes. The combination of anti-diabetic drugs with other anti-cancer drugs and phytochemicals can help prevent and treat this disease. PC cancer stem cells (CSCs) and how they migrate and develop into malignant tumors are discussed. A detailed explanation of the different mechanisms of diabetes development, which can enhance the pancreatic CSCs' proliferation by increasing the IGF factor levels, epigenetic modifications, DNA damage, and the influence of lifestyle factors like obesity, and inflammation, has been discussed. It also explains how cancer due to diabetes is associated with high mortality rates. One of the well-known diabetic drugs, metformin, can be combined with other anti-cancer drugs and prevent the development of PC and has been taken as one of the prime focus in this review. Overall, this paper provides insight into the relationship between diabetes and PC and the methods that can be employed to diagnose this disease at an earlier stage successfully.

Polyethylenimine, an Autophagy-Inducing Platinum-Carbene-Based Drug Carrier with Potent Toxicity towards Glioblastoma Cancer Stem Cells

The difficulty involved in the treatment of many tumours due to their recurrence and resistance to chemotherapy is tightly linked to the presence of cancer stem cells (CSCs). This CSC sub-population is distinct from the majority of cancer cells of the tumour bulk. Indeed, CSCs have increased mitochondrial mass that has been linked to increased sensitivity to mitochondrial targeting compounds. Thus, a platinum-based polyethylenimine (PEI) polymer-drug conjugate (PDC) was assessed as a potential anti-CSC therapeutic since it has previously displayed mitochondrial accumulation. Our results show that CSCs have increased specific sensitivity to the PEI carrier and to the PDC. The mechanism of cell death seems to be necrotic in nature, with an absence of apoptotic markers. Cell death is accompanied by the induction of a protective autophagy. The interference in the balance of this pathway, which is highly important for CSCs, may be responsible for a partial reversion of the stem-like phenotype observed with prolonged PEI and PDC treatment. Several markers also indicate the cell death mode to be capable of inducing an anti-cancer immune response. This study thus indicates the potential therapeutic perspectives of polycations against CSCs.

PROM1 and CTGF Expression in Childhood MLL-Rearrangement Acute Lymphoblastic Leukemia

The prognosis of over 90% of infant acute lymphoblastic leukemia (ALL) remains poor because of harboring the mixed-lineage leukemia gene (MLL) fusion. To give insight into the critical coexpressed genes related to the MLL-rearrangement (MLL-R) gene in childhood acute lymphoblastic leukemia, we integrated different bioinformatic methods. First, the gene expression data of MLL-R ALL and normal samples from GSE13159 and GSE13164 were analyzed using “compare” function in the Oncomine database. The top 150 overexpressed and 150 underexpressed genes were identified by the Oncomine website. Then, we employed the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) to define functional genes for the 300 DEGs. The Cytoscape identified two important networks for overexpressed genes, including 35 functional genes, among which PROM1, FLT3, CTGF, LGALS1, IGFBP7, ZNRF1, and RUNX2 were considered as the key genes because of their high expression in MLL-R ALL compared to the expression in other subclassification of leukemia in the MILE dataset. Further analysis of GSE68720, GSE19475, and Therapeutically Applicable Research to Generate Effective Treatments (TARGET) ALL (phase I) database confirmed the robust expression of 7 key genes in MLL-R compared to MLL-germline (MLL-G) childhood ALL. Kaplan-Meier analysis indicated that childhood ALL patients with high PROM1 and CTGF expression had significantly poor overall survival. These findings suggest that PROM1 and CTGF represent two potential therapeutic targets for childhood MLL-R ALL.

Stage-Specific Effect of Inositol Hexaphosphate on Cancer Stem Cell Pool during Growth and Progression of Prostate Tumorigenesis in TRAMP Model

Herein, we assessed the stage-specific efficacy of inositol hexaphosphate (IP6, phytic acid), a bioactive food component, on prostate cancer (PCa) growth and progression in a transgenic mouse model of prostate cancer (TRAMP). Starting at 4, 12, 20, and 30 weeks of age, male TRAMP mice were fed either regular drinking water or 2% IP6 in water for ~8-15 weeks. Pathological assessments at study endpoint indicated that tumor grade is arrested at earlier stages by IP6 treatment; IP6 also prevented progression to more advanced forms of the disease (~55-70% decrease in moderately and poorly differentiated adenocarcinoma incidence was observed in advanced stage TRAMP cohorts). Next, we determined whether the protective effects of IP6 are mediated via its effect on the expansion of the cancer stem cells (CSCs) pool; results indicated that the anti-PCa effects of IP6 are associated with its potential to eradicate the PCa CSC pool in TRAMP prostate tumors. Furthermore, in vitro assays corroborated the above findings as IP6 decreased the % of floating PC-3 prostaspheres (self-renewal of CSCs) by ~90%. Together, these findings suggest the multifaceted chemopreventive-translational potential of IP6 intervention in suppressing the growth and progression of PCa and controlling this malignancy at an early stage.

ZNF516 suppresses stem cell-like characteristics by regulating the transcription of Sox2 in colorectal cancer

This study aimed to explore the biological function and the molecular mechanism of the action of zinc-finger protein 516 (ZNF516) in suppressing stem cell-like characteristics and tumor progression in colorectal cancer (CRC). The expression profiles of ZNF516 in clinical samples and from The Cancer Genome Atlas (TCGA) CRC database were analyzed. Cell transfection was used to overexpress and knockdown ZNF516 in CRC cells. Cell counting kit-8 (CCK8) assays, transwell assays and flow cytometry were used to study cell proliferation, invasion and stem cell-like characteristics, respectively. Cycloheximide (CHX) was used to examine the effect of ZNF516 expression on Sox2 degradation. Finally, the effects of ZNF516 on tumor growth and metastasis were tested on xenograft tumor models and lung metastasis models in immunocompromised mice. We found that the expression level of ZNF516 was lower in TCGA CRC tissue and clinical CRC samples compared with that in normal colorectal mucosal cells. Overexpression of ZNF516 in CRC cells inhibited cell proliferation, colony formation, migration and invasion, whereas ZNF516 knockdown showed the opposite effects. In addition, ZNF516 overexpression inhibited the sphere-forming ability of CRC cells and suppressed the expression of CD133, CD44 and Oct4 in CRC cells. ZNF516 decreased the stability of Sox2 through a mechanism mediated by EGFR. By in vivo experiments using mouse tumor models, we further confirmed that ZNF516 attenuated tumor growth and alleviated lung metastasis in mice. In conclusion, ZNF516 functions as a tumor suppressor by regulating the transcription of Sox2 to inhibit cell proliferation, invasion, and the development of stem cell-like characteristics in CRC cells.

GLIS1-3: Links to Primary Cilium, Reprogramming, Stem Cell Renewal, and Disease

The GLI-Similar 1-3 (GLIS1-3) genes, in addition to encoding GLIS1-3 Krüppel-like zinc finger transcription factors, also generate circular GLIS (circGLIS) RNAs. GLIS1-3 regulate gene transcription by binding to GLIS binding sites in target genes, whereas circGLIS RNAs largely act as miRNA sponges. GLIS1-3 play a critical role in the regulation of many biological processes and have been implicated in various pathologies. GLIS protein activities appear to be regulated by primary cilium-dependent and -independent signaling pathways that via post-translational modifications may cause changes in the subcellular localization, proteolytic processing, and protein interactions. These modifications can affect the transcriptional activity of GLIS proteins and, consequently, the biological functions they regulate as well as their roles in disease. Recent studies have implicated GLIS1-3 proteins and circGLIS RNAs in the regulation of stemness, self-renewal, epithelial-mesenchymal transition (EMT), cell reprogramming, lineage determination, and differentiation. These biological processes are interconnected and play a critical role in embryonic development, tissue homeostasis, and cell plasticity. Dysregulation of these processes are part of many pathologies. This review provides an update on our current knowledge of the roles GLIS proteins and circGLIS RNAs in the control of these biological processes in relation to their regulation of normal physiological functions and disease.

Tumour Stem Cells in Breast Cancer

Tumour stem cells (CSCs) are a self-renewing population that plays important roles in tumour initiation, recurrence, and metastasis. Although the medical literature is extensive, problems with CSC identification and cancer therapy remain. This review provides the main mechanisms of CSC action in breast cancer (BC): CSC markers and signalling pathways, heterogeneity, plasticity, and ecological behaviour. The dynamic heterogeneity of CSCs and the dynamic transitions of CSC⁻ non-CSCs and their significance for metastasis are considered.

Proteomics Study of Mesenchymal Stem Cell-Like Cells Obtained from Tumor Microenvironment of Patients with Malignant and Benign Salivary Gland Tumors

Objective

Salivary gland tumors (SGTs) show some aggressive and peculiar clinicopathological behaviors that might be related to the components of the tumor microenvironment, especially mesenchymal stem cells (MSCs)-associated proteins. However, the role of MSCs-related proteins in SGTs tumorigenesis is poorly understood. This study aimed to isolate and characterize MSCs from malignant and benign tumor tissues and to identify differentially expressed proteins between these two types of MSCs.

Materials and Methods

In this experimental study, MSC-like cells derived from benign (pleomorphic adenoma, n=5) and malignant (mucoepidermoid carcinoma, n=5) tumor tissues were verified by fluorochrome antibodies and flow cytometric analysis. Differentially expressed proteins were identified using two-dimensional polyacrylamide gel electrophoresis (2DE) and Mass spectrometry.

Results

Results showed that isolated cells strongly expressed characteristic MSCs markers such as CD44, CD73, CD90, CD105, and CD166, but they did not express or weakly expressed CD14, CD34, CD45 markers. Furthermore, the expression of CD24 and CD133 was absent or near absent in both isolated cells. Results also discovered overexpression of Annexin A4 (Anxa4), elongation factor 1-delta (EF1-D), FK506 binding protein 9 (FKBP9), cytosolic platelet-activating factor acetylhydrolase type IB subunit beta (PAFAH1B), type II transglutaminase (TG2), and s-formylglutathione hydrolase (FGH) in MSCs isolated from the malignant tissues. Additionally, heat shock protein 70 (Hsp70), as well as keratin, type II cytoskeletal 7 (CK-7), were found to be overexpressed in MSCs derived from the benign ones.

Conclusion

Malignant and benign SGTs probably exhibit a distinct pattern of tissue proteins that are most likely related to the metabolic pathway. However, further studies in a large number of patients are required to determine the applicability of identified proteins as new targets for cancer therapy.

Comprehensive Atlas of Circulating Rare Cells Detected by SE-iFISH and Image Scanning Platform in Patients With Various Diseases

Objective

Circulating rare cells (CRCs) are known as a crucial nucleated cellular response to pathological conditions, yet the landscape of cell types across a wide variety of diseases lacks comprehensive understanding. This study aimed at detecting and presenting a full spectrum of highly heterogeneous CRCs in clinical practice and further explored the characterization of CRC subtypes in distinct biomarker combinations and aneuploid chromosomes among various disease groups.

Methods

Peripheral blood was obtained from 2,360 patients with different cancers and non-neoplastic diseases. CRC capture and identification were accomplished using a novel platform integrating subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) strategy with a high-throughput automated image scanning system, on which hemocyte, tumor, epithelial, endothelial, mesenchymal, and stemness biomarkers were immunostained and displayed simultaneously. Double chromosome enumeration probe (CEP8 and CEP12) co-detection was performed on isolated CRCs from an extended trial for two chromosome ploidy patterns.

Results

A comprehensive atlas categorizing the diverse CRCs into 71 subtypes outlining was mapped out. The presence of epithelial-mesenchymal transition (EMT) or endothelial-mesenchymal transition (EndoMT), the cells with progenitor property, hematologic CRCs expressing multiple biomarkers, CRCs at "naked nuclei" status, and the rarely reported aneuploid mesenchymal epithelial-endothelial fusion cluster were described. Circulating tumor cells (CTCs) were detected in 2,157 (91.4%) patients; the total numbers of CTCs and circulating tumor-derived endothelial cells (CTECs) were relatively higher in several digestive system cancer types and non-neoplastic infectious diseases (p < 0.05). Co-detection combining CEP8 and CEP12 showed a higher diagnostic specificity on account of 57.27% false negativity of CRC detection through a single probe of CEP8.

Conclusions

The alternative biomarkers and chromosomes to be targeted by SE-iFISH and the image scanning platform, along with the comprehensive atlas, offer insight into the heterogeneity of CRCs and reveal potential contributions to specific disease diagnosis and therapeutic target cell discovery.

The NOP14 nucleolar protein suppresses the function and stemness of melanoma stem-like cells through Wnt/beta-catenin signaling inactivation

Cancer stem cells (CSCs) are closely related to tumor occurrence, development, metastasis, drug resistance, and recurrence. The role of CSCs in melanoma is poorly understood. Our previous studies suggested that the NOP14 nucleolar protein (NOP14) is involved in melanoma pathogenesis regulation. Importantly, NOP14 overexpression inhibits the Wnt/beta (β)-catenin signaling pathway, an important mechanism regulating CSCs stemness. Therefore, in this study, we aimed to explore the role of NOP14 in the stemness and function of CSCs in melanoma in vitro. CD133, a stem cell marker, was used to identify melanoma stem-like cells (SLCs). NOP14 overexpression subsequently decreased the proportion of CD133⁺ SLCs, impaired the colony-forming capabilities, and downregulated the expression of Nanog, SOX2, and OCT4 stem cell markers in A375 and A875 cells, suggesting that NOP14 suppresses the stemness of melanoma SLCs. NOP14 overexpression suppressed the migration, invasion, and angiogenesis-inducing ability of A375-SLCs and A875-SLCs. NOP14 overexpression also inactivated Wnt/β-catenin signaling in melanoma CD133⁺ SLCs. The Wnt signaling activator BML-284 alleviated the effect of NOP14 overexpression on the stemness and function of melanoma CSCs. In conclusion, NOP14 suppresses the stemness and function of melanoma SLCs by inactivating Wnt/β-catenin signaling. Thus, NOP14 is a novel target for CSC treatment in melanoma.

Abbreviations: CSCs, cancer stem cells; SLCs, stem-like cells; NOP14, NOP14 nucleolar protein; SCID, severe combined immunodeficiency; β-catenin, beta-catenin; lv-NOP14, lentivirals expressing NOP14; PBS, phosphate buffer saline; HUVECs, human umbilical vein endothelial cells.

MicroRNAs and Corresponding Targets in Esophageal Cancer as Shown In Vitro and In Vivo in Preclinical Models

Squamous cell carcinoma of the esophagus is associated with a dismal prognosis. Therefore, identification of new targets and implementation of new treatment modalities are issues of paramount importance. Based on a survey of the literature, we identified microRNAs conferring antitumoral activity in preclinical in vivo experiments. In the category of miRs targeting secreted factors and transmembrane receptors, four miRs were up-regulated and 10 were down-regulated compared with five out of nine in the category transcription factors, and six miRs were down-regulated in the category enzymes, including metabolic enzymes. The down-regulated miRs have targets which can be inhibited by small molecules or antibody-related entities, or re-expressed by reconstitution therapy. Up-regulated miRs have targets which can be reconstituted with small molecules or inhibited with antagomirs.

Near-infrared (NIR) fluorescence-emitting small organic molecules for cancer imaging and therapy

We discuss recent advances made in the development of NIR fluorescence-emitting small organic molecules for tumor imaging and therapy.

The role of dietary polyphenols in osteosarcoma: A possible clue about the molecular mechanisms involved in a process that is just in its infancy

Osteosarcoma (OS) is a primary malignant bone tumor mainly affecting children, teenagers and young adults, being associated with early metastasis and poor prognosis. The beneficial effects of polyphenols have been investigated in different areas, including their potential to fight OS. Polyphenols are believed to reduce morbidity and/or slow down the development of cancer. This review aimed to assess the effect of polyphenols in OS and investigate their molecular mechanisms. It was observed that the broad spectrum of health-promoting properties of plant polyphenols in OS occurs mainly due to modulation of reactive oxygen species, anti-inflammatory activity, anti-angiogenesis, apoptosis inducer, inhibition of invasion and metastasis. However, it is worth mentioning that although the promising effects of polyphenols in the fight against OS, most of the studies have been performed using in vitro and in vivo animal models. Therefore, studies in humans are needed to validate the effectiveness of polyphenols in OS treatment. PRACTICAL APPLICATIONS: Polyphenols are widely used for various diseases, however, until now, their real role in the treatment of osteosarcoma remains unknown. This review provides a broad spectrum of research conducted with polyphenols and their potential as adjuvant therapy in the treatment of osteosarcoma. However, prior to their clinical application for osteosarcoma treatment, there is a need to isolate and identify specific polyphenolic compounds with high antitumor activity, increase their oral bioavailability, and to investigate their interactions with chemotherapeutic drugs being used in clinical practice.

Potential of Stem Cells and CART as a Potential Polytherapy for Small Cell Lung Cancer

Despite the increasing urgency of the problem of treating small cell lung cancer (SCLC), information on the causes of its development is fragmentary. There is no complete understanding of the features of antitumor immunity and the role of the microenvironment in the development of SCLC resistance. This impedes the development of new methods for the diagnosis and treatment of SCLC. Lung cancer and chronic obstructive pulmonary disease (COPD) have common pathogenetic factors. COPD is a risk factor for lung cancer including SCLC. Therefore, the search for effective approaches to prevention, diagnosis, and treatment of SCLC in patients with COPD is an urgent task. This review provides information on the etiology and pathogenesis of SCLC, analyses the effectiveness of current treatment options, and critically evaluates the potential of chimeric antigen receptor T cells therapy (CART therapy) in SCLC. Moreover, we discuss potential links between lung cancer and COPD and the role of endothelium in the development of COPD. Finally, we propose a new approach for increasing the efficacy of CART therapy in SCLC.

Cancerous and non-neoplastic stem cells in the stomach similarly express CD44 and CD133

CD44 and CD133 have been considered as cancer stem cell (CSC) markers. Stem cell markers are rarely described in healthy stomach tissues. However, the clinicopathological and prognostic value of CD44 and CD133 in gastric cancer remains controversial. This study investigated the expression of CD44 and CD133 in gastric cancer and non-neoplastic gastric mucosa. We used samples of primary gastric adenocarcinomas (n = 69), metastatic lymph nodes (n = 30), intestinal metaplasia (n = 17), and histologically normal gastric tissues of surgical margins (n = 54). The expression of CD44 and CD133 were studied in samples by immunohistochemistry. Fisher's exact test and a logistic regression model were used in this study. CD44 expression was observed in 12% of samples with intestinal metaplasia, 20% with lymph node metastases, 22% with normal mucosa, to 30% of samples with primary tumors. Most of these positive tumors showed immunostaining in less than 4% of cancerous cells, mainly in the diffuse type. CD133 expression was observed in 7% (intestinal metaplasia) to 46% (normal mucosa). In the positive cases of cancer (24%), in most of them, less than 3% of cells were marked. CD44 and CD133 expression in the histologically normal gastric mucosa was restricted to the deeper regions of the gastric crypts at the level where stem cells and progenitor cells are usually found. CD44 and CD133 expression occurs in few gastric cancer cells, mainly in diffuse carcinomas, and are expressed in histologically normal gastric mucosae. None of the markers are specific for cancer and are also present in intestinal metaplasia and the normal mucosa.

CAR-T therapy: Prospects in targeting cancer stem cells

Cancer stem cells (CSCs), a group of tumour cells with stem cell characteristics, have the ability of self-renewal, multi-lineage differentiation and tumour formation. Since CSCs are resistant to conventional radiotherapy and chemotherapy, their existence may be one of the root causes of cancer treatment failure and tumour progression. The elimination of CSCs may be effective for eventual tumour eradication. Because of the good therapeutic effects without major histocompatibility complex (MHC) restriction and the unique characteristics of CSCs, chimeric antigen receptor T-cell (CAR-T) therapy is expected to be an important method to eliminate CSCs. In this review, we have discussed the feasibility of CSCs-targeted CAR-T therapy for cancer treatment, summarized current research and clinical trials of targeting CSCs with CAR-T cells and forecasted the challenges and future direction from the perspectives of toxicity, persistence and potency, trafficking, infiltration, immunosuppressive tumour microenvironment, and tumour heterogeneity.

Characterization of Glioblastoma Cancer Stem Cells Sorted by Sedimentation Field-Flow Fractionation Using an Ultrahigh-Frequency Range Dielectrophoresis Biosensor

Cancer stem cells (CSCs) appear to be an essential target for cancer therapies, in particular, in brain tumors such as Glioblastoma. Nevertheless, their isolation is made difficult by their low content in culture or tumors (<5% of the tumor mass) and is essentially based on the use of fluorescent or magnetic labeling techniques, increasing the risk of differentiation induction. The use of label-free separation methods such as sedimentation field-flow fractionation (SdFFF) is promising, but it becomes necessary to consider a coupling with a detection and characterization method for future identification and purification of CSCs from patient-derived tumors. In this study, we demonstrate for the first time the capability of using an ultrahigh-frequency range dielectrophoresis fluidic biosensor as a detector. This implies an important methodological adaptation of SdFFF cell sorting by the use of a new compatible carrier liquid DEP buffer (DEP-B). After SdFFF sorting, subpopulations derived from U87-MG and LN18 cell lines undergo biological characterization, demonstrating that using DEP-B as a carrier liquid, we sorted by SdFFF subpopulations with specific differentiation characteristics: F1 = differentiated cells/F2 = CSCs. These subpopulations presented high-frequency crossover (HFC) values similar to those measured for standard differentiated (around 110 MHz) and CSC (around 80 MHz) populations. This coupling appeared as a promising solution for the development of an online integration of these two complementary label-free separation/detection technologies.

Slug and CD133 expression are associated with peritoneal carcinomatosis and survival in gastric cancer

Background

Slug is an activating transcription factor involved in epithelial-mesenchymal transition, and CD133 is a cancer stem cell marker found in various cancers, including gastric cancer (GC). We investigated the relationship between Slug and CD133 and the occurrence of peritoneal carcinomatosis and survival in patients with GC.

Methods

This retrospective study included 196 patients with stage 2 or 3 GC who underwent curative surgery with D2 lymph node dissection and adjuvant chemotherapy between 2001 and 2009. We analyzed the expression of Slug, CD133, ABCG2, E-cadherin, vimentin, NEDD9, and SMAD4 in surgical tissue specimens using immunohistochemical analysis to determine their prognostic value.

Results

Among the 196 patients, expression of Slug was elevated in 157 tumors (81%) while the expression of CD133 was high in 153 tumors (81%). The expression of Slug and CD133 in combination significantly predicted peritoneal relapse (P=0.002). High Slug and high CD133 expression were significantly associated with poor peritoneal relapse-free survival [hazard ratio (HR), 7.239; P=0.007] and overall survival (HR, 1.682; P=0.027) in multivariate Cox analysis.

Conclusions

Our study shows that a high Slug and high CD133 expression status is predictive of peritoneal recurrence in high-risk resected GC patients. They are also a poor prognostic factor for peritoneal relapse-free survival and overall survival.

CEACAM5 overexpression is a reliable characteristic of CD133-positive colorectal cancer stem cells

BACKGROUND

CD133 (prominin-1) is the most commonly used molecular marker of the cancer stem cells (CSCs) that maintain tumor progression and recurrence in colorectal cancer. However, the proteome of CSCs directly isolated from colorectal tumors based on CD133 expression has never been investigated.

OBJECTIVE

To reveal biomarkers of CD133-positive colorectal CSCs.

METHODS

Thirty colorectal tumor samples were collected from patients undergoing bowel resection. CD133-positive and CD133-negative cells were isolated by FACS. Comparative proteomic profiling was performed by LC-MS/MS analysis combined with label-free quantification. Verification of differentially expressed proteins was performed by flow cytometry or ELISA. CD133-knockout Caco-2 and HT-29 cell lines were generated using CRISPR-Cas9 gene editing.

RESULTS

LC-MS/MS analysis identified 29 proteins with at least 2.5-fold higher expression in CD133-positive cells versus CD133-negative cells. Flow cytometry confirmed CEACAM5 overexpression in CD133-positive cells in all clinical samples analyzed. S100A8, S100A9, and DEFA1 were differentially expressed in only a proportion of the samples. CD133 knockout in the colon cancer cell lines Caco-2 and HT-29 did not affect the median level of CEACAM5 expression, but led to higher variance of the percentage of CEACAM5-positive cells.

CONCLUSIONS

High CEACAM5 expression in colorectal cancer cells is firmly associated with the CD133-positive colorectal CSC phenotype, but it is unlikely that CD133 directly regulates CEACAM5 expression.

Tailoring drug co-delivery nanosystem for mitigating U-87 stem cells drug resistance

Glioblastoma multiforme (GBM) is the most prevalent form of brain tumor, which generally has a poor prognosis. According to consensus, recurrence of the tumor and chemotherapy resistance acquisition are the two distinguishing features of GBM originated from glioblastoma stem cells (GSCs). To eliminate these obstacles inherent in GBM chemotherapy, targeting GSCs through a smart drug delivery system has come to the front position of GBM therapeutics. In this study, B19 aptamer (Apt)-conjugated polyamidoamine (PAMAM) G4C12 dendrimer nanoparticles (NPs), called Apt-NPs, were formulated for the co-delivery of paclitaxel (PTX) and temozolomide (TMZ) to U-87 stem cells. These drugs were loaded using a double emulsification solvent evaporation method. As a result, drug-loaded Apt-NPs significantly inhibited the tumor growth of U-87 stem cells, by the initiation of apoptosis via the downregulation of autophagic and multidrug resistance (MDR) genes. Additionally, by their downregulation by qPCR of CD133, CD44, SOX2, and the canonical Wnt/β-catenin pathway, cell proliferation has substantially decreased. Altogether, the results demonstrate that this intelligent drug co-delivery system is capable of effectively transferring PTX and TMZ to U-87 stem cells and without any toxic effect on Apt-NPs alone to U-87 stem cells. Furthermore, the designed dendrimer-based pharmaceutical system along with single-stranded B19 aptamer might be utilized as a new therapeutic strategy for the treatment of U-87 stem cells drug resistance in the GBM.

Targeted Drug Therapy to Overcome Chemoresistance in Triple-negative Breast Cancer

Triple-negative Breast Cancer (TNBC) is the most aggressive and prevailing breast cancer subtype. The chemotherapeutics used in the treatment of TNBC suffer from chemoresistance, dose-limiting toxicities and off-target side effects. As a result, conventional chemotherapeutics are unable to prevent tumor growth, metastasis and result in failure of therapy. Various new targets such as BCSCs surface markers (CD44, CD133, ALDH1), signaling pathways (IL-6/JAK/STAT3, notch), pro and anti-apoptotic proteins (Bcl-2, Bcl-xL, DR4, DR5), hypoxic factors (HIF-1α, HIF-2α) and drug efflux transporters (ABCC1, ABCG2 and ABCB1) have been exploited to treat TNBC. Further, to improve the efficacy and safety of conventional chemotherapeutics, researchers have tried to deliver anticancer agents specifically to the TNBCs using nanocarrier based drug delivery. In this review, an effort has been made to highlight the various factors responsible for the chemoresistance in TNBC, novel molecular targets of TNBC and nano-delivery systems employed to achieve sitespecific drug delivery to improve efficacy and reduce off-target side effects.

Mechanisms involved in selecting and maintaining neuroblastoma cancer stem cell populations, and perspectives for therapeutic targeting

Pediatric neuroblastomas (NBs) are heterogeneous, aggressive, therapy-resistant embryonal tumours that originate from cells of neural crest (NC) origin and in particular neuroblasts committed to the sympathoadrenal progenitor cell lineage. Therapeutic resistance, post-therapeutic relapse and subsequent metastatic NB progression are driven primarily by cancer stem cell (CSC)-like subpopulations, which through their self-renewing capacity, intermittent and slow cell cycles, drug-resistant and reversibly adaptive plastic phenotypes, represent the most important obstacle to improving therapeutic outcomes in unfavourable NBs. In this review, dedicated to NB CSCs and the prospects for their therapeutic eradication, we initiate with brief descriptions of the unique transient vertebrate embryonic NC structure and salient molecular protagonists involved NC induction, specification, epithelial to mesenchymal transition and migratory behaviour, in order to familiarise the reader with the embryonic cellular and molecular origins and background to NB. We follow this by introducing NB and the potential NC-derived stem/progenitor cell origins of NBs, before providing a comprehensive review of the salient molecules, signalling pathways, mechanisms, tumour microenvironmental and therapeutic conditions involved in promoting, selecting and maintaining NB CSC subpopulations, and that underpin their therapy-resistant, self-renewing metastatic behaviour. Finally, we review potential therapeutic strategies and future prospects for targeting and eradication of these bastions of NB therapeutic resistance, post-therapeutic relapse and metastatic progression.

Stemness-Suppressive Effect of Bibenzyl from Dendrobium ellipsophyllum in Human Lung Cancer Stem-Like Cells

Cancer stem-like cells (CSCs) are key mediators driving tumor initiation, metastasis, therapeutic failure, and subsequent cancer relapse. Thus, targeting CSCs has recently emerged as a potential strategy to improve chemotherapy. In this study, the anticancer activity and stemness-regulating capacity of 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl (TDB), a bibenzyl extracted from Dendrobium ellipsophyllum, are revealed in CSCs of various human lung cancer cells. Culture with TDB (5-10 μM) strongly abolished tumor-initiating cells in lung cancer H460, H23, and A549 cells in both anchorage-dependent and anchorage-independent colony formation assays. Through the 3D single-spheroid formation model, attenuation of self-renewal capacity was observed in CSC-enriched populations treated with 1-10 μM TDB for 7 days. Flow cytometry analysis confirmed the attenuation of %cell overexpressing CD133, a CSC biomarker, in TDB-treated lung cancer spheroids. TDB at 5-10 μM remarkably suppressed regulatory signals of p-Akt/Akt, p-GSK3β/GSK3β, and β-catenin corresponding to the downregulated mRNA level of stemness transcription factors including Nanog, Oct4, and Sox2. Moreover, the antiapoptosis Bcl-2 and Mcl-1 proteins, which are downstream molecules of Akt signaling, were evidently decreased in CSC-enriched spheroids after culture with TDB (1-10 μM) for 24 h. Interestingly, the diminution of Akt expression by specific siAkt effectively reversed suppressive activity of TDB targeting on the CSC phenotype in human lung cancer cells. These findings provide promising evidence of the inhibitory effect of TDB against lung CSCs via suppression of Akt/GSK3β/β-catenin cascade and related proteins, which would facilitate the development of this bibenzyl natural compound as a novel CSC-targeted therapeutic approach for lung cancer treatment.