Metastatic Cancer Stem Cells Research Articles

Everything you ever wanted to know about cancer stem cells in neuroendocrine neoplasms but were afraid to ask

While the role of cancer stem cells (CSCs) in tumorigenesis, chemoresistance, metastasis and relapse has been extensively studied in solid tumors, such as adenocarcinomas or sarcomas, the same cannot be said for neuroendocrine neoplasms (NENs). While lagging, CSCs have been described in numerous NENs including gastrointestinal and pancreatic neuroendocrine neoplasms (PanNENs), and they have been found to play critical roles in tumor initiation, progression, and treatment resistance. However, it seems there is still skepticism regarding the role of CSCs in NENs, even in light of studies that support the CSC model in these tumors and the therapeutic benefit of targeting them. For example, in lung neuroendocrine carcinoids, a high percentage of CSCs have been found in atypical carcinoids, suggesting the presence of CSCs in these cancers. In PanNENs, CSCs marked by aldehyde dehydrogenases or CD90 have been identified, and targeting CSCs with inhibitors of molecular pathways has shown therapeutic potential. Overall, while evidence exists for the presence of CSCs in NENs, either the CSC field has neglected NENs or the NEN field has not fully embraced the CSC model. Both might apply and/or may be a consequence of the fact that NENs are a relatively rare and heterogeneous tumor entity, with confusing histology and nomenclature to match. Regardless, this review intends to summarize our current knowledge of CSCs in NENs and highlight the importance of understanding the role of CSCs in the biology of these rare tumors, with a special focus on developing targeted therapies to improve patients' outcomes.

Spatial transcriptomic revealed intratumor heterogeneity and cancer stem cell enrichment in colorectal cancer metastasis

Metastasis is the main cause of mortality in colorectal cancer (CRC) patients. Exploring the mechanisms of metastasis is of great importance in both clinical and fundamental CRC research. CRC is a highly heterogeneous disease with variable therapeutic outcomes of treatment. In this study, we applied spatial transcriptomics (ST) to generate a tissue-wide transcriptome from two primary colorectal cancer tissues and their matched liver metastatic tissues. Spatial RNA information showed intratumoral heterogeneity (ITH) of both primary and metastatic tissues. The comparison of gene expressions across tissues revealed an apparent enrichment of cancer stem cells (CSCs) in metastatic tissues and identified FOXD1 as a novel metastatic CSC marker. Trajectory and pseudo-time analyses revealed distinct evolutionary trajectories and a dedifferentiation-differentiation process during metastasis. CellphoneDB analysis suggested a dominant interaction of CD74-MIF with tumor cells in metastatic tissues. Further analysis confirmed FOXD1 as a maker of CSCs and the predictor of patient survival, especially in metastatic diseases. Our study found ITH of primary and metastatic tissues and provides novel insights into the cellular mechanisms underlying liver metastasis of CRC and foundations for therapeutic strategies for CRC metastasis.

MicroRNA (miRNA) PROFILING IN PROSTATE CANCER CARCINOGENESIS: EXPLORATORY RESEARCH

Future research will continue to be carried out in terms of looking for molecular markers involved in the early processes of carcinogenesis, metastasis and therapeutic targets in prostate cancer patients. MicroRNAs (miRNAs) are small noncoding RNAs that contribute to prostate cancer progression by controlling genes involved in the androgen receptor (AR) signaling pathway, ectopic expression of proteins involved in the cell cycle and apoptosis, epithelial-mesenchymal transition (EMT) and metastasis of cancer stem cells (CSCs). This study was an exploratory study, the aim was to assess miRNA expression in low histopathological grade prostate cancer compared with high histopathological grade prostate cancer. The novelty of this research is to assess the 25 most increased (up-regulated) and 25 lowest (down-regulated) miRNAs from 800 types of miRNA. Next, we will analyze the mechanisms and confirm the carcinogenesis of prostate cancer. The research results can be used for further research data, especially for targeted therapy in prostate cancer patients.

Epidermal growth factor receptor inhibition potentiates chemotherapeutics-mediated sensitization of metastatic breast cancer stem cells.

Metastasis has been a cause of the poor prognosis and cancer relapse of triple-negative breast cancer (TNBC) patients. The metastatic nature of TNBC is contributed by the breast cancer stem cells (CSCs) which have been implicated in tumorigenesis. Higher expression of epidermal growth factor receptor (EGFR) in breast CSCs has been used as a molecular target for breast cancer therapeutics. Thus, it necessitates the design and generation of efficacious EGFR inhibitors to target the downstream signaling associated with the cellular proliferation and tumorigenesis of breast cancer. To generate efficacious EGFR inhibitors that can potentiate the chemotherapeutic-mediated mitigation of breast cancer tumorigenesis. We identified small molecule EGFR inhibitors using molecular docking studies. In-vitro screening of the compounds was undertaken to identify the cytotoxicity profile of the small-molecule EGFR inhibitors followed by evaluation of the non-cytotoxic compounds in modulating the doxorubicin-induced migration, in-vitro tumorigenesis potential, and their effect on the pro-apoptotic genes' and protein markers' expression in TNBC cells. Compound 1e potentiated the doxorubicin-mediated inhibitory effect on proliferation, migration, in-vitro tumorigenesis capacity, and induction of apoptosis in MDA-MB-231 cells, and in the sorted CD24+-breast cancer cells and CD24-/CD44+-breast CSC populations. Orthotopic xenotransplantation of the breast CSCs-induced tumors in C57BL/6J mice was significantly inhibited by the low dose of Doxorubicin in the presence of compound 1e as depicted by molecular and immunohistochemical analysis. Thus, the study suggests that EGFR inhibition-mediated sensitization of the aggressive and metastatic breast CSCs in TNBCs toward chemotherapeutics may reduce the relapse of the disease.

TET1 regulates stem cell properties and cell cycle of Cancer stem cells in triple-negative breast cancer via DNA demethylation

The role of cancer stem cells in metastasis, recurrence, and resistance to conventional therapies is significant. Addressing these cells could potentially decrease cancer reoccurrences and mortality rates. TET1, a crucial gene involved in stem cell self-renewal and potency, may also play a part in cancer stem cells, which warrants further research.To explore the role of TET1 in cancer stem cells, we conducted experiments involving loss and gain. We then analyzed factors such as migration, invasion, cell cycle, cell viability, mammosphere formation, and the CD44+/CD24- subpopulation of cancer cells. We also investigate the influence of TET1 on CCNB1, CDK1, and OCT4.Our study reveals that TET1 can regulate the phenotype of cancer stem cells via OCT4. Additionally, it can control the cell cycle by increasing CDK1 and CCNB1 levels. These findings suggest that targeting DNA methylation and TET1 could be an effective strategy to overcome obstacles posed by Cancer stem cells.Our research also indicates that TET1 can influence the phenotype of cancer stem cells and the cell cycle of breast cancer cells potentially through OCT4, CCNB1, and CDK1. This highlights the importance of TET1 in breast cancer cases and suggests a potential therapeutic approach through DNA methylation and modulation of TET1.

Hypoxia-induced circ-CDYL-EEF1A2 transcriptional complex drives lung metastasis of cancer stem cells from hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is often associated with poor outcomes due to lung metastasis. ICAM-1+ circulating tumor cells, termed circulating cancer stem cells (CCSCs), possess stem cell–like characteristics. However, it is still unexplored how their presence indicates lung metastasis tendency, and particularly, what mechanism drives their lung metastasis. Here, we demonstrated that a preoperative CCSC count in 5 mL of blood (CCSC5) of >3 was a risk factor for lung metastasis in clinical HCC patients. The CSCs overexpressed with circ-CDYL entered the bloodstream and developed lung metastases in mice. Mechanistically, circ-CDYL promoted COL14A1 expression and thus ERK signaling to facilitate epithelial-mesenchymal transition. Furthermore, we uncovered that an RNA-binding protein, EEF1A2, acted as a novel transcriptional (co-) factor to cooperate with circ-CDYL and initiate COL14A1 transcription. A high circ-CDYL level is caused by HIF-1⍺-mediated transcriptional upregulation of its parental gene CDYL and splicing factor EIF4A3 under a hypoxia microenvironment. Hence, the hypoxia microenvironment enables the high-tendency lung metastasis of ICAM-1+ CCSCs through the HIF-1⍺/circ-CDYL-EEF1A2/COL14A1 axis, potentially allowing clinicians to preoperatively detect ICAM-1+ CCSCs as a real-time biomarker for precisely deciding HCC treatment strategies.

Differential gene expression of immunity and inflammation genes in colorectal cancer using targeted RNA sequencing.

Colorectal cancer (CRC) is a heterogeneous disease caused by molecular changes, as driver mutations, gene methylations, etc., and influenced by tumor microenvironment (TME) pervaded with immune cells with both pro- and anti-tumor effects. The studying of interactions between the immune system (IS) and the TME is important for developing effective immunotherapeutic strategies for CRC. In our study, we focused on the analysis of expression profiles of inflammatory and immune-relevant genes to identify aberrant signaling pathways included in carcinogenesis, metastatic potential of tumors, and association of Kirsten rat sarcoma virus (KRAS) gene mutation. A total of 91 patients were enrolled in the study. Using NGS, differential gene expression analysis of 11 tumor samples and 11 matching non-tumor controls was carried out by applying a targeted RNA panel for inflammation and immunity genes containing 475 target genes. The obtained data were evaluated by the CLC Genomics Workbench and R library. The significantly differentially expressed genes (DEGs) were analyzed in Reactome GSA software, and some selected DEGs were used for real-time PCR validation. After prioritization, the most significant differences in gene expression were shown by the genes TNFRSF4, IRF7, IL6R, NR3CI, EIF2AK2, MIF, CCL5, TNFSF10, CCL20, CXCL11, RIPK2, and BLNK. Validation analyses on 91 samples showed a correlation between RNA-seq data and qPCR for TNFSF10, RIPK2, and BLNK gene expression. The top differently regulated signaling pathways between the studied groups (cancer vs. control, metastatic vs. primary CRC and KRAS positive and negative CRC) belong to immune system, signal transduction, disease, gene expression, DNA repair, and programmed cell death. Analyzed data suggest the changes at more levels of CRC carcinogenesis, including surface receptors of epithelial or immune cells, its signal transduction pathways, programmed cell death modifications, alterations in DNA repair machinery, and cell cycle control leading to uncontrolled proliferation. This study indicates only basic molecular pathways that enabled the formation of metastatic cancer stem cells and may contribute to clarifying the function of the IS in the TME of CRC. A precise identification of signaling pathways responsible for CRC may help in the selection of personalized pharmacological treatment.

Single-cell tracking with Compton-PET: An in silico feasibility study

The tracking of single cells is a critical component of developing new therapeutic techniques, particularly for metastatic cancer cells, immune cells, and stem cells. To achieve this, various types of scanners, such as PET, MRI, fluorescence imaging, and optical imaging, are used. In this study, we evaluated the feasibility of using the Compton-PET system for single-cell tracking. Unlike conventional PET scanners that consist of a single detector ring, the Compton-PET system comprises an additional scatterer ring within the primary absorber ring. This design enables the acquisition of both double and single events simultaneously, where doubles refer to the detection of both annihilation photons in either of the two rings, and singles refer to the detection of only one photon scattered in the scatterer detector and subsequently absorbed in the absorber detector. This study is simulation-based. We propose utilising both doubles and singles events to track the unknown trajectory of single cells in the Compton-PET system. We investigated a range of velocities and activities of single cells and compared the tracking performance of the Compton-PET and PET scanners. Our findings indicate that the use of doubles and singles events together in Compton-PET improves the tracking performance compared to PET scanners.

Abstract 2450: Transforming intestinal stem cells into metastatic cancer Stem cells by aberrantly activated cytokine-STAT5A signaling

Abstract Background: Lgr5 intestinal stem cells (ISC) are augmented by colorectal (CRC), but it is not clear if the aberrant Lgr5 ISCs result in the metastatic phenotypes of CRC, suggesting that epistasis-involved mutations in CRC suppressor genes or oncogene control Lgr5 ISC transformation into cancer stem cells (CSC). Somatic mutations in STAT5A or B are highly associated with CRC. Cytokine-STAT5 action is essential for Lgr5 ISC stemness, and enhanced STAT5 phosphorylation can induce Lgr5 ISC differentiation into secretory niche cells. Using human and mouse tumoroids, and organoid xerograph models, we aim to determine the effects of STAT5 oncogenic activation on Lgr5 ISC malignant and metastatic phenotypes. Methods: Colorectal surgical specimen from CRC and hepatic metastatic CRC patients were collected to perform RNAseq or single cell RNAseq (scRNAseq) analysis. Compound-mutant mice with STAT5 loss or gain of function in Apcmin+/- mice, were generated by crossing Apcmin+/- mice with Lgr5CreER and Rs26CreER, and Stat5f/f (loss of function of Stat5) or icS5f/f (gain of function of STAT5A) mice. CRISPR/Cas9 gene editing was applied to engineer APC mutations in human epithelial cell lines or Apc mutations in Lgr5 ISCs. Apc-mutant Lgr5 ISCs or tumoroids from Apcmin+/- mice combined with STAT5 loss or gain of function were differentiated, then were under intra-abdominal xenotransplantation. APC-mutant intestinal epithelial cell lines were used to determined CSC migration in the presence of STAT5 activation. STAT5 inhibitors were used to treat Apcmin+/- mice or tumoroids. Results: Human subject studies revealed that hepatic metastatic CRC patients exhibited the robustly increased STAT5A and/or Lgr5 colonic cancer cells. Murine studies showed that constitutively STAT5A activation (Ca-pYSTAT5) in colonic Apcmin+/- CSCs promoted CSC migration, invasion and metastasis. In vivo migration assay showed that transient STAT5A activation in the APC-mutant intestinal epithelia accelerated the migration of APC-mutant epithelia. Ex Vivo tumoroid xenotransplantation showed that Ca-pYSTAT5 resulted in tumoroid invasion into liver. Lineage tracing analysis showed that Ca-pYSTAT5 expanded Lgr5 CSCs in tumoroids and drove Lgr5 CSCs to hepatic metastasis. Importantly, Stat5 deletion in Lgr5 ISCs abolishes colon cancer orgnoids invasion. Pharmacological inhibition of STAT5 dimerization leads to Lgr5 cancer organoid degeneration and partially annihilated intestinal adenoma in Apcmin+/-. CHIP-seq analysis showed that Ca-pYSTAT5 increased an aberrant high level of Bcl6 expression by inducing super-enhancer activation in the Bcl-6 locus. Conclusion: Aberrantly activated Cytokine-STAT5A signaling is required for ISC malignancy and CSC hepatic metastasis. STAT5 blockade could be important to impair CRC metastasis. Citation Format: Haifeng Li, Wen Gao, Ruixue Liu, Xiaonan Han. Transforming intestinal stem cells into metastatic cancer Stem cells by aberrantly activated cytokine-STAT5A signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2450.

Bioinspired One Cell Culture Isolates Highly Tumorigenic and Metastatic Cancer Stem Cells Capable of Multilineage Differentiation

Adv. Sci. 2020, 7, 2000259 https://doi.org/10.1002/advs.202000259 In the originally published article, some figures in the Supporting Information were incorrect. In these figures, incorrect images were used by accident for the control conditions of 1% alginate hydrogel of Day 5 in Figure S3a, Ucells in Figure S12b, Day 1 of 2D cells (Passage 3, EGM) in Figure S15, Ucells (Differentiation medium A) and Mcells (Maintenance medium) in Figure S16, and of 1-1 and M-1-1 in Figure S27, which occurred during initial the preparation of the figures. The corrections do not affect the conclusions of the article. Supporting Information file was updated on April 26, 2023. The authors apologize for any inconvenience caused.

Targeted ferroptotic potency of ferrous oxide nanoparticles-diethyldithiocarbamate nanocomplex on the metastatic liver cancer.

Existing treatments are frequently ineffective in combating liver cancer (LC) due to its rapid growth, high metastatic potential, and chemoresistance. Thus, inducing ferroptosis, a new non-apoptotic regulated cell death-dependent massive iron overload-mediated lipid peroxidation, is an alternative effective approach for treating LC. The efficient trigger of ferroptosis requires blocking cellular antioxidant (anti-ferroptosis) response and selectivity to avoid harming other healthy tissues. In this study, green chemically synthesized ferrous oxide nanoparticles (F(II) NPs) were used for enhancing selective iron accumulation in tumor tissue, while diethyldithiocarbamate (DE) was for inhibiting the antioxidant system (glutathione and aldehyde dehydrogenase (ALDH) 2) which protects the tumor from damage-dependent lipid peroxides. Thus, F(II) NPs were used with DE as nanocomplex (DF(II) NPs) and its anti-LC activity compared to ferrous oxide DF(II). DF(II) NPs outperformed the typical complex of DF(II) in eradicating metastatic LC cells in HepG2 cells and a chemically induced metastatic LC animal model, as evidenced by flow cytometry, histological and immunohistochemical analyses, and α-fetoprotein depletion. The superior therapeutic potency-dependent ferroptotic activity of DF(II) NPs, attributed to their higher selective accumulation (∼77%) than DF(II) in tumor tissues (liver and lung), resulted in a strong elevation of cellular lipid peroxidation with extreme suppression of nuclear related factor 2 (Nrf2) transcriptional activity, glutathione (GSH), glutathione peroxidase 4, and ALDH2. Subsequently, a severe inhibition in the expression of oncogenes and metastatic cancer stem cell genes was recorded in DF(II) NPs-treated LC animal group. In contrast to DF(II), DF(II) NPs were able to normalize liver functions and did not show any variations in hematological and histological parameters in the blood and tissues of DF(II) NPs-treated normal mouse group. These findings validate the potency and safety of DF(II) nanocomplex as a promising nanodrug for combating metastatic LC.

Epithelial-mesenchymal transition and stemness of breast cancer cells: Effect of viscoelasticity of the substrate to mimics microenvironment

Metastasis is one of the greatest challenges in cancer treatment today. Normal mammary epithelial cells are optimally supported by interaction with a soft matrix (microenvironment) with elastic modulus of about 800 Pa. However, after transformation, breast tissue becomes progressively stiffer and tumour cells become significantly more contractile and hyper-responsive to matrix elasticity. In addition, importantly, the cancer cells penetrate into blood vessel and enter the circulation during metastasis. The modulus of fluid such as blood or mucus has very low stiffness of around 50 Pa. For this reason, the critical association between cancer cell phenotype and the change of matrix rigidity with an order of magnitude smaller should be emphasizing. This review highlights the current understanding of epithelial-mesenchymal transition and cancer stem cells in metastasis, and identified importance for investigation on artificial extracellular matrix with different viscoelastic properties, which is required to mimics in vivo microenvironment. The substrate damping coefficient (tand) as potential physical parameter emerged the important linkage to cellular motility, cancer stemness, and epithelial-mesenchymal transition induction. Although further investigation is required to clarify the efficacy of environmental stimuli (tand) for tumors exhibiting stem cell-like properties, this review indicates that the cancer cells incubated on softer substrate might lead to express cancer stem cell biomarkers exhibiting high expression.

ΔNp63/p73 drive metastatic colonization by controlling a regenerative epithelial stem cell program in quasi-mesenchymal cancer stem cells.

Cancer stem cells (CSCs) may serve as the cellular seeds of tumor recurrence and metastasis, and they can be generated via epithelial-mesenchymal transitions (EMTs). Isolating pure populations of CSCs is difficult because EMT programs generate multiple alternative cell states, and phenotypic plasticity permits frequent interconversions between these states. Here, we used cell-surface expression of integrin β4 (ITGB4) to isolate highly enriched populations of human breast CSCs, and we identified the gene regulatory network operating in ITGB4+ CSCs. Specifically, we identified ΔNp63 and p73, the latter of which transactivates ΔNp63, as centrally important transcriptional regulators of quasi-mesenchymal CSCs that reside in an intermediate EMT state. We found that the transcriptional program controlled by ΔNp63 in CSCs is largely distinct from the one that it orchestrates in normal basal mammary stem cells and, instead, it more closely resembles a regenerative epithelial stem cell response to wounding. Moreover, quasi-mesenchymal CSCs repurpose this program to drive metastatic colonization via autocrine EGFR signaling.

Targeting autophagy in pancreatic cancer: The cancer stem cell perspective.

Pancreatic cancer is currently the seventh leading cause of cancer-related deaths worldwide, with the estimated death toll approaching half a million annually. Pancreatic ductal adenocarcinoma (PDAC) is the most common (>90% of cases) and most aggressive form of pancreatic cancer, with extremely poor prognosis and very low survival rates. PDAC is initiated by genetic alterations, usually in the oncogene KRAS and tumor suppressors CDKN2A, TP53 and SMAD4, which in turn affect a number of downstream signaling pathways that regulate important cellular processes. One of the processes critically altered is autophagy, the mechanism by which cells clear away and recycle impaired or dysfunctional organelles, protein aggregates and other unwanted components, in order to achieve homeostasis. Autophagy plays conflicting roles in PDAC and has been shown to act both as a positive effector, promoting the survival of pancreatic tumor-initiating cells, and as a negative effector, increasing cytotoxicity in uncontrollably expanding cells. Recent findings have highlighted the importance of cancer stem cells in PDAC initiation, progression and metastasis. Pancreatic cancer stem cells (PaCSCs) comprise a small subpopulation of the pancreatic tumor, characterized by cellular plasticity and the ability to self-renew, and autophagy has been recognised as a key process in PaCSC maintenance and function, simultaneously suggesting new strategies to achieve their selective elimination. In this review we evaluate recent literature that links autophagy with PaCSCs and PDAC, focusing our discussion on the therapeutic implications of pharmacologically targeting autophagy in PaCSCs, as a means to treat PDAC.

In Vitro Photodynamic Treatment Modality for A375 Melanoma Cell Line Using a Sulphonated Aluminum Phthalocyanine Chloride-Photosensitizer-Gold Nanoparticle Conjugate.

Metastatic melanoma cancer stem cells are subpopulations that have been identified and linked to tumor progression, immunoevasive behavior, drug resistance, and metastasis, leading to a poor prognosis. Photodynamic therapy (PDT) is an approach to eradicate cancer through a photochemical process which directly generates reactive oxygen species (ROS). This study investigated the impact of PDT using an aluminum phthalocyanine gold nanoparticle (AlPcS4Cl-AuNP) conjugate for targeting melanoma stem cells. The isolated stem cells were irradiated at 673.2 nm with a radiant exposure of 5 J/cm2. Post-irradiation signs of cell death were determined using microscopy and biochemical assays. A possible enhanced effect of ROS in inducing cell death could be seen when AlPcS4Cl was conjugated to AuNPs. Nanoparticles as carriers promote the efficient cellular uptake of photosensitizers, enhancing organelle accumulation and the targeted therapy of cancerous cells. A biochemical assay revealed significant post-irradiation signs of cell death. The measurement of adenosine triphosphate (ATP) content revealed a decrease in cell proliferation. The study suggested an approach directed at expanding the knowledge on PDT to improve cancer treatment. Understanding the cell death mechanism through which ROS influence cancer stem cells (CSCs) is, therefore, useful for improving PDT efficiency and preventing tumor recurrence and metastasis.

A synchronized dual drug delivery molecule targeting cancer stem cells in tumor heterogeneity and metastasis

Cancer stem-like cells (CSCs) represent a key barrier to successful therapy for triple-negative breast cancer (TNBC). CSCs promote the emergence of chemoresistance, triggering relapse and resulting in a poor prognosis. We herein present CDF-TM, a new small molecule-based binary prodrug conjugated with SN-38 and 3,4-difluorobenzylidene curcumin (CDF) that is specifically activated in hypoxic conditions. CDF-TM treatment significantly induced apoptosis in TNBC-derived 3D spheroids, accompanied with caspase-3 activation as well as the attenuation of tumor stemness with evidence of reduction in aldehyde dehydrogenase 1 (ALDH1) activity and the CD44high/CD24low phenotype. An in vivo orthotopic allograft model was used to investigate its effects on tumor growth and metastasis. The dissemination of CSCs from primary allografts was impaired by CDF-TM, along with inhibition of tumor growth via eradication of CSCs and downregulation of multidrug resistance 1 (MDR1). This new small molecule-based binary prodrug offers a novel therapeutic option for metastatic TNBC.

Fluid shear stress induces cell migration via RhoA-YAP1-autophagy pathway in liver cancer stem cells

ABSTRACT Fluid shear stress (FSS) regulates the metastasis of hepatocellular carcinoma (HCC), but the role of the RhoA-YAP1-autophagy pathway in HCC remains unclear. Due to the core role of liver cancer stem cells (LCSCs) in HCC metastasis and recurrence, we explored the RhoA-YAP1-autophagy pathway in LCSCs under FSS. Our results indicate that LCSCs have stronger proliferation and cell spheroidization abilities. FSS (1 dyn/cm2) upregulated the migration of LCSCs and autophagy protein markers, inducing LC3B aggregation and autophagosome formation in LCSCs. Mechanistically, FSS promoted YAP1 dephosphorylation and transport to the nucleus, which is mediated by RhoA, inducing autophagy. Finally, inhibition of autophagy suppressed cell migration in LCSCs under FSS. In conclusion, FSS promoted the migration of LCSCs via the RhoA-YAP1-autophagy pathway.

Comprehensive Computational Analysis of Honokiol Targets for Cell Cycle Inhibition and Immunotherapy in Metastatic Breast Cancer Stem Cells.

Breast cancer stem cells (BCSCs) play a critical role in chemoresistance, metastasis, and poor prognosis of breast cancer. BCSCs are mostly dormant, and therefore, activating them and modulating the cell cycle are important for successful therapy against BCSCs. The tumor microenvironment (TME) promotes BCSC survival and cancer progression, and targeting the TME can aid in successful immunotherapy. Honokiol (HNK), a bioactive polyphenol isolated from the bark and seed pods of Magnolia spp., is known to exert anticancer effects, such as inducing cell cycle arrest, inhibiting metastasis, and overcoming immunotherapy resistance in breast cancer cells. However, the molecular mechanisms of action of HNK in BCSCs, as well as its effects on the cell cycle, remain unclear. This study aimed to explore the potential targets and molecular mechanisms of HNK on metastatic BCSC (mBCSC)-cell cycle arrest and the impact of the TME. Using bioinformatics analyses, we predicted HNK protein targets from several databases and retrieved the genes differentially expressed in mBCSCs from the GEO database. The intersection between the differentially expressed genes (DEGs) and the HNK-targets was determined using a Venn diagram, and the results were analyzed using a protein-protein interaction network, hub gene selection, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, genetic alteration analysis, survival rate, and immune cell infiltration levels. Finally, the interaction between HNK and two HNK-targets regulating the cell cycle was analyzed using molecular docking analysis. The identified potential therapeutic targets of HNK (PTTH) included CCND1, SIRT2, AURKB, VEGFA, HDAC1, CASP9, HSP90AA1, and HSP90AB1, which can potentially inhibit the cell cycle of mBCSCs. Moreover, our results showed that PTTH could modulate the PI3K/Akt/mTOR and HIF1/NFkB/pathways. Overall, these findings highlight the potential of HNK as an immunotherapeutic agent for mBCSCs by modulating the tumor immune environment.

The role of selected molecular factors in ovarian cancer metastasis.

The main reason for treatment failure in ovarian cancer is chemoresistance and the presence of metastasis. Ascites, whichallows the physical movement of cancer cells, the lymphovascular pathway, and several molecular factors and signalling axes, are involved in metastasis. Ascites, with the involvement of cytokines and chemokines, MAPK/STAT1 and NOTCH as well as CXCL12/CXCR4 signaling pathways and circulating anoikis induces cancer dissemination, in particular to the peritoneum and omentum. The spread of lymphatic and bloodstream cancer cells is a multi-stage process. Tumour infiltration of the stroma and lymphovascular space (LVSI) produces biologically active cancer-associated fibroblasts and macrophages (CAFs, TAMs) that secrete numerous cytokines, chemokines and growth factors, inhibit NK function, induce epithelial-mesenchymal transition (EMT), resulting in an increase of the metastatic potential of cancer cells and the formation of cancer stem cells (CSCs). Overexpression of some genes, and microRNAs, in LVSI-(LMGS) associated with metastasis has been identified. The role of extracellular vesicles (EVs) transporting metastasis-associated factors has been described as has the role of cancer stem cells (CSCs) in chemotherapy resistance and metastasis. Sirtuins, enzymes involved in metastasis formation, have also been detected. Certain types of microRNAs (miR-509-3p, microRNA-506-3p) and melatonin have been shown to inhibit metastasis.

Epithelial-Mesenchymal Transition and Cancer Stem Cells.

Epithelial-mesenchymal transition (EMT), a cellular phenotypic change from epithelial to mesenchymal-like features, is related to the resistance and metastasis of cancer stem cells (CSCs). Several signal transduction mechanisms induce EMT, which causes the gene expression alteration to induce the acquisition of resistance and metastasis in cancer. EMT is characterized with high gene expression of cadherin 2 (N-cadherin) and vimentin, and sparse cell-cell junction. The cells with EMT-phenotype have migration, metastasis and drug-resistance capacity, which are main characteristics of CSCs. It seems that the main population of CSCs exhibits EMT phenotype, whereas some populations consist of phenotypes other than EMT. In this chapter, EMT mechanism, phenotypic features of EMT and CSCs, signal transduction in EMT and CSCs, differences between EMT and CSCs, and the role of EMT in CSCs are described.