Multifaceted role of microRNAs in gastric cancer stem cells: Mechanisms and potential biomarkers

MicroRNAs(miRNAs)have received much attention in the past decade as potential key epigenomic regulators of tumors and cancer stem cells(CSCs).The abnormal expression of miRNAs is responsible for different phenotypes of gastric cancer stem cells(GCSCs).Some specific miRNAs could be used as promising biomarkers and therapeutic targets for the identification of GCSCs.This review summarizes the coding process and biological functions of miRNAs and demon-strates their role and efficacy in gastric cancer(GC)metastasis,drug resistance,and apoptosis,especially in the regulatory mechanism of GCSCs.It shows that the overexpression of onco-miRNAs and silencing of tumor-suppressor miRNAs can play a role in promoting or inhibiting tumor metastasis,apart from the initial formation of GC.It also discusses the epigenetic regulation and potential clinical applications of miRNAs as well as the role of CSCs in the pathogenesis of GC.We believe that this review may help in designing novel therapeutic approaches for GC.

Emerging role of microRNAs in cancer stem cells:Implications in cancer therapy

A small subset of cancer cells that act as tumor initiating cells or cancer stem cells(CSCs) maintain self-renewal and growth promoting capabilities of cancer and are responsible for drug/treatment resistance,tumor recurrence and metastasis. Due to their potential clinical importance,many researchers have put their efforts over decades to unravel the molecular mechanisms that regulate CSCs functions. Micro RNAs(mi RNAs) which are 21-23 nucleotide long,endogenous noncoding RNAs,regulate gene expression through gene silencing at post-transcriptional level by binding to the 3'-untranslated regions or the open reading frames of target genes,thereby result in target mR NA degradation or its translational repression and serve important role in several cellular,physiological and developmental processes. Aberrant mi RNAs expression and their implication in CSCs regulation by controlling asymmetric cell division,drug/treatment resistance and metastasis make mi RNAs a tool of great therapeutic potential against cancer. Recent advancements on the biological complexities of CSCs,modulation in CSCs properties by mi RNA network and development of mi RNA based treatment strategies specifically targeting the CSCs as an attractive therapeutic targets for clinical application are being critically analysed.

Role of microRNA-regulated cancer stem cells in recurrent hepatocellular carcinoma

Among the most common cancers,hepatocellular carcinoma(HCC)has a high rate of tumor recurrence,tumor dormancy,and drug resistance after initial successful chemotherapy or radiotherapy.A small subset of cancer cells,cancer stem cells(CSCs),exhibit stem cell characteristics and are present in various cancers,including HCC.The dysregulation of microRNAs(miRNAs)often accompanies the occurrence and development of HCC.miRNAs can influence tumorigenesis,progression,recurrence,and drug resistance by regulating CSCs properties,which supports their clinical utility in managing and treating HCC.This review summarizes the regulatory effects of miRNAs on CSCs in HCC with a special focus on their impact on HCC recurrence.

Effect of colorectal cancer stem cells on the development and metastasis of colorectal cancer

The relevant mechanism of tumor-associated macrophages(TAMs)in the treatment of colorectal cancer patients with immune checkpoint inhibitors(ICIs)is discussed,and the application prospects of TAMs in reversing the treatment tolerance of ICIs are discussed to provide a reference for related studies.As a class of drugs widely used in clinical tumor immunotherapy,ICIs can act on regulatory molecules on cells that play an inhibitory role-immune checkpoints-and kill tumors in the form of an immune response by activating a variety of immune cells in the immune system.The sensitivity of patients with different types of colorectal cancer to ICI treatment varies greatly.The phenotype and function of TAMs in the colorectal cancer microenvironment are closely related to the efficacy of ICIs.ICIs can regulate the phenotypic function of TAMs,and TAMs can also affect the tolerance of colorectal cancer to ICI therapy.TAMs play an important role in ICI resistance,and making full use of this target as a therapeutic strategy is expected to improve the immunotherapy efficacy and prognosis of patients with colorectal cancer.

Prostaglandin D2 regulation of autophagy affects stemness of gastric cancer stem cells

Objective:To explore the effect and mechanism of prostaglandins D2(PGD2)on the stemness of gastric cancer stem cells(GCSCs).Methods:7901-GCSCs were enriched by serum-free culture method;then the positivity rate of CD44,a stemness marker,was detected by flow cytometry in serum-free cultured 7901-GCSCs;the sphere-forming ability was detected by the sphere-forming assay after stimulation with different concentrations of PGD2(2.5,5,10)μg/mL,and the expression of stemness-related indicators(OCT4,CD44)and autophagyrelated proteins(LC3,Beclin-1)after PGD2 stimulation was detected by the western blot assay in different concentrations.The expression of stemness-related indexes(OCT4,CD44)and autophagy-related proteins(LC3,Beclin-1)were detected by Western blot assay after stimulation with different concentrations of PGD2.The expression of autophagy-related proteins after stimulation with different concentrations of CQ(2.5,5,10)μM was detected by Western blot experiment.The protein expression of autophagy-related proteins(LC3,Beclin-1)and stemness-related indexes(OCT4,CD44)was detected by Western blot experiment after PGD2 as well as PGD2+CQ treatment.Results:Flow cytometry results showed that the expression of CD44 positivity was increased in serum-free cultured 7901-GCSCs compared with gastric cancer cells SGC-7901(P<0.05),which fulfilled the needs of subsequent experiments.The results of stem cell spheroid formation assay showed that the spheroid formation ability of 7901-GCSCs in the PGD2 group was significantly weakened compared with that of the DMSO group(P<0.05).Western blot results showed that the protein expression of stemness-related indexes(OCT4,CD44)was down-regulated in the 7901-GCSCs in the PGD2 group compared with that of the DMSO group(P<0.05),and the expression of autophagy-related proteins(LC3,Beclin-1)expression increased(P<0.05).Compared with the DMSO group,the expression of autophagy-related proteins(LC3,Beclin-1)was decreased in the CQ group(P<0.05).Western blot results also showed that the expression of cellular autophagy-related proteins and stemness-related indexes in the PGD2+CQ group was not significantly changed compared with that of the DMSO group(ns:the difference was not significant),suggesting that the CQ could block the effect of PGD2 on the expression of stemness markers in 7901-GCSCs.7901-GCSCs stemness inhibition.Conclusion:PGD2 may affect the stemness of 7901-GCSCs by regulating autophagy.

Clinical implications of microRNAs in liver cancer stem cells

The prognosis of patients diagnosed with hepatocellular carcinoma (HCC) is often dismal, mainly due to late presentation, high recurrence rate, and frequent resistance to chemotherapy and radiotherapy. Accumulating evidence on the differential microRNA (miRNA) expression patterns between non-tumor and HCC tissues or between liver cancer stem cells (CSCs) and non-CSC subsets and the significant clinical implications of these differences suggest that miRNAs are a promising, non-invasive marker for the prognosis and diagnosis of the disease. This perspective article summarizes the current knowledge of miRNAs in liver CSCs and highlights the need for further investigations of the role of miRNAs in regulating liver CSC subsets for possible future clinical applications.

Role of cancer stem cell ecosystem on breast cancer metastasis and related mouse models

Breast cancer metastasis is responsible for most breast cancer-related deaths and is influenced by many factors within the tumor ecosystem,including tumor cells and microenvironment.Breast cancer stem cells(BCSCs)constitute a small population of cancer cells with unique characteristics,including their capacity for self-renewal and differentiation.Studies have shown that BCSCs not only drive tumorigenesis but also play a crucial role in promoting metastasis in breast cancer.The tumor microenvironment(TME),composed of stromal cells,immune cells,blood vessel cells,fibroblasts,and microbes in proximity to cancer cells,is increasingly recognized for its crosstalk with BCSCs and role in BCSC survival,growth,and dissemination,thereby influencing metastatic ability.Hence,a thorough understanding of BCSCs and the TME is critical for unraveling the mechanisms underlying breast cancer metastasis.In this review,we summarize current knowledge on the roles of BCSCs and the TME in breast cancer metastasis,as well as the underlying regulatory mechanisms.Furthermore,we provide an overview of relevant mouse models used to study breast cancer metastasis,as well as treatment strategies and clinical trials addressing BCSC-TME interactions during metastasis.Overall,this study provides valuable insights for the development of effective therapeutic strategies to reduce breast cancer metastasis.

Interplay and therapeutic implications of colorectal cancer stem cells,tumor microenvironment,and gut microbiota

This article discusses the interplay between colorectal cancer(CRC)stem cells,tumor microenvironment(TME),and gut microbiota,emphasizing their dynamic roles in cancer progression and treatment resistance.It highlights the adaptability of CRC stem cells,the bidirectional influence of TME,and the multifaceted impact of gut microbiota on CRC.The manuscript proposes innovative therapeutic strategies focusing on these interactions,advocating for a shift towards personalized and ecosystem-targeted treatments in CRC.The conclusion underscores the importance of continued research in these areas for developing effective,personalized therapies.

Carnitine palmitoyltransferase-II inactivity promotes malignant progression of metabolic dysfunction-associated fatty liver disease via liver cancer stem cell activation

BACKGROUND Metabolic dysfunction-associated fatty liver disease(MAFLD)is one of the main chronic liver diseases.However,the roles of mitochondrial carnitine palmitoyl transferase-II(CPT-II)downregulation and liver cancer stem cell(LCSC)activation remain to be identified.AIM To investigate the dynamic alterations in CPT-II inactivity and LCSC activation during the malignant progression of MAFLD.METHODS Dynamic models of mouse MAFLD were generated via the consumption of a high-fat diet or the addition of 2-fluorenylacetamide for hepatocarcinogenesis.The mice were divided into groups on the basis of hematoxylin and eosin staining.Biochemistries,CPT-II,intrahepatic T cells,and LCSCs were determined and confirmed in clinical samples.The mitochondrial membrane potential(MMP)was analyzed.Differentially expressed genes were screened via RNA sequencing and enriched in KEGG pathways or GO functions.RESULTS Dynamic models of MAFLD malignant transformation were successfully generated on the basis of pathological examination.Hepatic lipid accumulation was associated with the loss of mitochondrial CPT-II activity and alterations in the MMP,with decreases in liver CD3+or CD4+T cells and increased AFP levels.In the lipid accumulation microenvironment,mitochondrial CPT-II was inactivated,followed by aberrant activation of CD44+or CD24+LCSCs,as validated in MAFLD or hepatocellular carcinoma patient samples.In terms of mechanism,the biological process category focused mainly on the metabolic regulation of cells in response to external stimuli.The enriched molecular functions included protein binding,cell apoptosis,and cell proliferation.CONCLUSION CPT-II inactivity promotes the malignant progression of MAFLD via the loss of innate immune function and abnormal LCSC activation.

Research Progress of Breast Cancer Stem Cell Stemness and Breast Cancer Recurrence

Currently, breast cancer is the most common malignant tumour in Chinese women with a high incidence rate, and recurrence and metastasis are the main reasons affecting survival. Breast Cancer Stem Cells (BCSCs) are stem cells capable of continuous regeneration in vivo with strong self-renewal ability and multidirectional differentiation potential, which are highly tumourigenic and insensitive to radiotherapy and chemotherapy, and are highly susceptible to breast cancer recurrence. Therefore, exploring the stemness of BCSCs and their mechanism associated with recurrence is important for developing new therapeutic strategies, improving therapeutic efficacy, and improving patient prognosis.

Research progress on lung cancer stem cells in epidermal growth factor receptor–tyrosine kinase inhibitor targeted therapy resistance in lung adenocarcinoma

Lung cancer is the leading cause of cancer-related deaths globally.In recent years,with the widespread use of genetic testing,epidermal growth factor receptor–tyrosine kinase inhibitor(EGFR-TKI)–targeted drugs have been efficacious to patients with lung adenocarcinoma exhibiting EGFR mutations.However,resistance to treatment is inevitable and eventually leads to tumor progression,recurrence,and reduction in the overall treatment efficacy.Lung cancer stem cells play a crucial role in the development of resistance toward EGFR-TKI–targeted therapy for lung adenocarcinoma.Lung cancer stem cells possess self-renewal,multilineage differentiation,and unlimited proliferation capabilities,which efficiently contribute to tumor formation and ultimately lead to tumor recurrence andmetastasis.In this study,we evaluated the origin,markers,stemness index,relevant classic studies,resistance mechanisms,related signaling pathways,and strategies for reversing lung cancer stem cell resistance to EGFR-TKIs to provide new insights on delaying or reducing resistance and to improve the treatment efficacy of patients with EGFR-mutated lung adenocarcinoma in the future.

Exploring the Pivotal Association of AI in Cancer Stem Cells Detection and Treatment

Cancer stem cells(CSCs),or tumor-initiating cells(TICs),are cancerous cell subpopulations that remain while tumor cells propagate as a unique subset and exhibit multiple applications in several diseases.They are responsible for cancer cell initiation,development,metastasis,proliferation,and recurrence due to their self-renewal and differentiation abilities in many kinds of cells.Artificial intelligence(AI)has gained significant attention because of its vast applications in various fields including agriculture,healthcare,transportation,and robotics,particularly in detecting human diseases such as cancer.The division and metastasis of cancerous cells are not easy to identify at early stages due to their uncontrolled situations.It has provided some real-time pictures of cancer progression and relapse.The purpose of this review paper is to explore new investigations into the role of AI in cancer stem cell progression and metastasis and in regenerative medicines.It describes the association of machine learning and AI with CSCs along with its numerous applications from cancer diagnosis to therapy.This review has also provided key challenges and future directions of AI in cancer stem cell research diagnosis and therapeutic approach.

Advancing Cancer Stem Cell-Targeted Therapeutic Applications

Cancer stem cells(CSCs),first identified in blood cancers,are increasingly recognized as significant biomarkers and targets in tumor therapy due to their metastatic potential and role in cancer recurrence.Recent research has demonstrated the dedication of scientists in targeting CSCs to explore novel therapeutic strategies.Many types of cancer exhibit metastasis,heterogeneity,and resistance to treatment,all of which are influenced by CSCs.These cells utilize various transcription factors and signaling pathways to carry out these functions.By identifying and understanding these pathways,new therapeutic breakthroughs can be achieved.Thus,targeting cancer stem cells holds great potential and importance in cancer treatment.Moreover,CSCs offer promising avenues for treating otherwise incurable diseases.However,targeting CSCs presents challenges such as immunological rejection and disease recurrence.Advancing research into CSCs may reveal new insights in the fight against cancer and ultimately improve human health.This review explores the roles of CSCs in cancer development and treatment,aiming to uncover new therapeutic approaches.

Molecular modulation of autophagy: New venture to target resistant cancer stem cells

Autophagy is a highly regulated catabolic process in which superfluous,damaged organelles and other cytoplasmic constituents are delivered to the lysosome for clearance and the generation of macromolecule substrates during basal or stressed conditions.Autophagy is a bimodal process with a context dependent role in the initiation and the development of cancers.For instance,autophagy provides an adaptive response to cancer stem cells to survive metabolic stresses,by influencing disease propagation via modulation of essential signaling pathways or by promoting resistance to chemotherapeutics.Autophagy has been implicated in a cross talk with apoptosis.Understanding the complex interactions provides an opportunity to improve cancer therapy and the clinical outcome for the cancer patients.In this review,we provide a comprehensive view on the current knowledge on autophagy and its role in cancer cells with a particular focus on cancer stem cell homeostasis.

Regulatory RNAs,microRNA,long-non coding RNA and circular RNA roles in colorectal cancer stem cells

The properties of cancer stem cells(CSCs),such as self-renewal,drug resistance,and metastasis,have been indicated to be responsible for the poor prognosis of patients with colon cancers.The epigenetic regulatory network plays a crucial role in CSC properties.Regulatory non-coding RNA(ncRNA),including microRNAs,long noncoding RNAs,and circular RNAs,have an important influence on cell physiopathology.They modulate cells by regulating gene expression in different ways.This review discusses the basic characteristics and the physiological functions of colorectal cancer(CRC)stem cells.Elucidation of these ncRNAs will help us understand the pathological mechanism of CRC progression,and they could become a new target for cancer treatment.

Reporter gene systems for the identification and characterization of cancer stem cells

Cancer stem cells(CSCs)are tumor cells that share functional characteristics with normal and embryonic stem cells.CSCs have increased tumor-initiating capacity and metastatic potential and lower sensitivity to chemo-and radiotherapy,with important roles in tumor progression and the response to therapy.Thus,a current goal of cancer research is to eliminate CSCs,necessitating an adequate phenotypic and functional characterization of CSCs.Strategies have been developed to identify,enrich,and track CSCs,many of which distinguish CSCs by evaluating the expression of surface markers,the initiation of specific signaling pathways,and the activation of master transcription factors that control stemness in normal cells.We review and discuss the use of reporter gene systems for identifying CSCs.Reporters that are under the control of aldehyde dehydrogenase 1A1,CD133,Notch,Nanog homeobox,Sex-determining region Y-box 2,and POU class 5 homeobox can be used to identify CSCs in many tumor types,track cells in real time,and screen for drugs.Thus,reporter gene systems,in combination with in vitro and in vivo functional assays,can assess changes in the CSCs pool.We present relevant examples of these systems in the evaluation of experimental CSCs-targeting therapeutics,demonstrating their value in CSCs research.

Gastric cancer stem cells in gastric carcinogenesis,progression,prevention and treatment

In recent decades,the study of the mechanism of tumorigenesis has brought much progress to cancer treatment.However,cancer stem cell(CSC)theory has changed previous views of tumors,and has provided a new method for treatment of cancer.The discovery of CSCs and their characteristics have contributed to understanding the molecular mechanism of tumor genesis and development,resulting in a new effective strategy for cancer treatment.Gastric CSCs(GCSCs)are the basis for the onset of gastric cancer.They may be derived from gastric stem cells in gastric tissues,or bone marrow mesenchymal stem cells.As with other stem cells,GCSCs highly express drug-resistance genes such as aldehyde dehydrogenase and multidrug resistance,which are resistant to chemotherapy and thus form the basis of drug resistance.Many specific molecular markers such as CD44 and CD133 have been used for identification and isolation of GCSCs,diagnosis and grading of gastric cancer,and research on GCSC-targeted therapy for gastric cancer.Therefore,discussion of the recent development and advancements in GCSCs will be helpful for providing novel insight into gastric cancer treatment.

Influence of adriamycin on changes in Nanog, Oct-4, Sox2, ARID1 and Wnt5b expression in liver cancer stem cells

AIM: To determine the influence of Adriamycin (ADM) on the changes in Nanog, Oct4, Sox2, as well as, in ARID1 and Wnt5b expression in liver cancer stem cells.

Leucine-rich repeat-containing G protein-coupled receptor 5 marks different cancer stem cell compartments in human Caco-2 and LoVo colon cancer lines

BACKGROUND Colon cancer cell lines are widely used for research and for the screening of drugs that specifically target the stem cell compartment of colon cancers.It was reported that colon cancer carcinoma specimens contain a subset of leucine-rich repeatcontaining G protein-coupled receptor 5(LGR5)-expressing stem cells,these socalled“tumour-initiating”cells,reminiscent in their properties of the normal intestinal stem cells(ISCs),may explain the apparent heterogeneity of colon cancer cell lines.Also,colon cancer is initiated by aberrant Wnt signaling in ISCs known to express high levels of LGR5.Furthermore,in vivo reports demonstrate the clonal expansion of intestinal adenomas from a single LGR5-expressing cell.AIM To investigate whether colon cancer cell lines contain cancer stem cells and to characterize these putative cancer stem cells.METHODS A portable fluorescent reporter construct based on a conserved fragment of the LGR5 promoter was used to isolate the cell compartments expressing different levels of LGR5 in two widely used colon cancer cell lines(Caco-2 and LoVo).These cells were then characterized according to their proliferation capacity,gene expression signatures of ISC markers,and their tumorigenic properties in vivo and in vitro.RESULTS The data revealed that the LGR5 reporter can be used to identify and isolate a classical intestinal crypt stem cell-like population from the Caco-2,but not from the LoVo,cell lines,in which the cancer stem cell population is more akin to B lymphoma Moloney murine leukemia virus insertion region 1 homolog(+4 crypt)stem cells.This sub-population within Caco-2 cells exhibits an intestinal cancer stem cell gene expression signature and can both self-renew and generate differentiated LGR5 negative progeny.Our data also show that cells expressing high levels of LGR5/enhanced yellow fluorescent protein(EYFP)from this cell line exhibit tumorigenic-like properties in vivo and in vitro.In contrast,cell compartments of LoVo that are expressing high levels of LGR5/EYFP did not show these stem cell-like properties.Thus,cells that exhibit high levels of LGR5/EYFP expression represent the cancer stem cell compartment of Caco-2 colon cancer cells,but not LoVo cells.CONCLUSION Our findings highlight the presence of a spectrum of different ISC-like compartments in different colon cancer cell lines.Their existence is an important consideration for their screening applications and should be taken into account when interpreting drug screening data.We have generated a portable LGR5-reporter that serves as a valuable tool for the identification and isolation of different colon cancer stem cell populations in colon cancer lines.

Properties and feasibility of using cancer stem cells in clinical cancer treatment

Cancer treatment failure, drug resistance, or metastatic recurrence are thought to be caused mainly by the existence of a very small number of cancer stem cells(CSCs). The characteristics of this subgroup of cells include self-renewal, tumorigenesis, multiple differentiation and high invasiveness, metastasis, and drug resistance potential. Many studies have demonstrated that CSCs play important roles in tumor growth, spread and metastatic relapse after treatment, and are closely related to the prognosis of patients.From a therapeutic viewpoint, deep insights into the CSCs biology, development of specific therapeutic strategies for targeting CSCs, and characterization of their microenvironment could be an ideal way to combat cancer.