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 o...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.展开更多
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 CD4...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.展开更多
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 ...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.展开更多
Prostate cancer, one of the most frequently occurring cancers in men, is a heterogeneous disease involving multiple cell types within tumors. This tumor heterogeneity at least partly results from genomic instability l...Prostate cancer, one of the most frequently occurring cancers in men, is a heterogeneous disease involving multiple cell types within tumors. This tumor heterogeneity at least partly results from genomic instability leading to sub-clonal cellular differentiation. The differentiated cell populations originate from a small subset of cells with tumor-initiating and stem-like properties. These cells, termed prostate cancer stem cells(PCSCs), play crucial roles in disease progression, drug resistance, and relapse. This review discusses the origin, hierarchy, and plasticity of PCSCs;methods for isolation and enrichment of PCSCs;and various cellular and metabolic signaling pathways involved in PCSC induction and maintenance, as well as therapeutic targeting.展开更多
Cancer stem cells(CSCs)are a small proportion of the cells that exist in cancer tissues.They are considered to be the culprit of tumor genesis,development,drug resistance,metastasis and recurrence because of their sel...Cancer stem cells(CSCs)are a small proportion of the cells that exist in cancer tissues.They are considered to be the culprit of tumor genesis,development,drug resistance,metastasis and recurrence because of their self-renewal,proliferation,and differentiation potential.The elimination of CSCs is thus the key to cure cancer,and targeting CSCs provides a new method for tumor treatment.Due to the advantages of controlled sustained release,targeting and high biocompatibility,a variety of nanomaterials are used in the diagnosis and treatments targeting CSCs and promote the recognition and removal of tumor cells and CSCs.This article mainly reviews the research progress of nanotechnology in sorting CSCs and nanodrug delivery systems targeting CSCs.Furthermore,we identify the problems and future research directions of nanotechnology in CSC therapy.We hope that this review will provide guidance for the design of nanotechnology as a drug carrier so that it can be used in clinic for cancer therapy as soon as possible.展开更多
Cancer stem cells(CSCs) are a small subset of cells in cancers that are thought to initiate tumorous transformation and promote metastasis, recurrence, and resistance to treatment. Growing evidence has revealed the ex...Cancer stem cells(CSCs) are a small subset of cells in cancers that are thought to initiate tumorous transformation and promote metastasis, recurrence, and resistance to treatment. Growing evidence has revealed the existence of CSCs in various types of cancers and suggested that CSCs differentiate into diverse lineage cells that contribute to tumor progression. We may be able to overcome the limitations of cancer treatment with a comprehensive understanding of the biological features and mechanisms underlying therapeutic resistance in CSCs. This review provides an overview of the properties, biomarkers, and mechanisms of resistance shown by CSCs. Recent findings on metabolic features, especially fatty acid metabolism and ferroptosis in CSCs, are highlighted, along with promising targeting strategies. Targeting CSCs is a potential treatment plan to conquer cancer and prevent resistance and relapse in cancer treatment.展开更多
Over the past 2 decades,cancer stem cells(CSCs)have been identified as the root cause of cancer occurrence,progression,chemoradioresistance,recurrence,and metastasis.Targeting CSCs is a novel therapeutic strategy for ...Over the past 2 decades,cancer stem cells(CSCs)have been identified as the root cause of cancer occurrence,progression,chemoradioresistance,recurrence,and metastasis.Targeting CSCs is a novel therapeutic strategy for cancer management and treatment.Liver cancer(LC)is a malignant disease that can endanger human health.Studies are increasingly suggesting that changes in the liver mechanical microenvironment are a primary driver triggering the occurrence and development of liver cancer.In this review,we summarize current understanding of the roles of the liver mechano-microenvironment and liver cancer stem cells(LCSCs)in liver cancer progression.We also discuss the relationship between the mechanical heterogeneity of liver cancer tissues and LCSC recruitment and metastasis.Finally,we highlight potential mechanosensitive molecules in LCSCs and mechanotherapy in liver cancer.Understanding the roles and regulatory mechanisms of the mechano-microenvironment and LCSCs may provide fundamental insights into liver cancer progression and aid in further development of novel therapeutic strategies.展开更多
Cancer stem cells(CSCs)are the main cause of tumor growth,invasion,metastasis and recurrence.Recently,CSCs have been extensively studied to identify CSCspecific surface markers as well as signaling pathways that play ...Cancer stem cells(CSCs)are the main cause of tumor growth,invasion,metastasis and recurrence.Recently,CSCs have been extensively studied to identify CSCspecific surface markers as well as signaling pathways that play key roles in CSCs self-renewal.The involvement of CSCs in the pathogenesis of gastrointestinal(GI)cancers also highlights these cells as a priority target for therapy.The diagnosis,prognosis and treatment of GI cancer have always been a focus of attention.Therefore,the potential application of CSCs in GI cancers is receiving increasing attention.This review summarizes the role of CSCs in GI cancers,focusing on esophageal cancer,gastric cancer,liver cancer,colorectal cancer,and pancreatic cancer.In addition,we propose CSCs as potential targets and therapeutic strategies for the effective treatment of GI cancers,which may provide better guidance for clinical treatment of GI cancers.展开更多
Obesity,the global pandemic since industrialization,is the number one lifestylerelated risk factor for premature death,which increases the incidence and mortality of various diseases and conditions,including cancer.In...Obesity,the global pandemic since industrialization,is the number one lifestylerelated risk factor for premature death,which increases the incidence and mortality of various diseases and conditions,including cancer.In recent years,the theory of cancer stem cells(CSCs),which have the capacity for self-renewal,metastasis and treatment resistance,has been bolstered by increasing evidence.However,research on how obesity affects CSCs to facilitate cancer initiation,progression and therapy resistance is still in its infancy,although evidence has already begun to accumulate.Regarding the ever-increasing burden of obesity and obesity-related cancer,it is pertinent to summarize evidence about the effects of obesity on CSCs,as elucidating these effects will contribute to the improvement in the management of obesity-related cancers.In this review,we discuss the association between obesity and CSCs,with a particular focus on how obesity promotes cancer initiation,progression and therapy resistance through CSCs and the mechanisms underlying these effects.In addition,the prospect of preventing cancer and targeting the mechanisms linking obesity and CSCs to reduce cancer risk or to improve the survival of patients with cancer is considered.展开更多
Head and neck squamous cell carcinoma is the seventh most common cancer worldwide with high mortality rates.Amongst oral cavity cancers,tongue carcinoma is a very common and aggressive oral cavity carcinoma.Despite th...Head and neck squamous cell carcinoma is the seventh most common cancer worldwide with high mortality rates.Amongst oral cavity cancers,tongue carcinoma is a very common and aggressive oral cavity carcinoma.Despite the implementation of a multimodality treatment regime including surgical intervention,chemo-radiation as well as targeted therapy,tongue carcinoma shows a poor overall 5-year survival pattern,which is attributed to therapy resistance and recurrence of the disease.The presence of a rare population,i.e.,cancer stem cells(CSCs)within the tumor,are involved in therapy resistance,recurrence,and distant metastasis that results in poor survival patterns.Therapeutic agents targeting CSCs have been in clinical trials,although they are unable to reach into therapy stage which is due to their failure in trials.A more detailed understanding of the CSCs is essential for identifying efficient targets.Molecular signaling pathways,which are differentially regulated in the CSCs,are one of the promising targets to manipulate the CSCs that would provide an improved outcome.In this review,we summarize the current understanding of molecular signaling associated with the maintenance and regulation of CSCs in tongue squamous cell carcinoma in order to emphasize the need of the hour to get a deeper understanding to unravel novel targets.展开更多
Objective:To evaluate the effects of ethanol extract from Ardisia gigantifolia leaves on cell proliferation and cancer stem cell(CSC)number in gastric cancer.Methods:The inhibitory effect of Ardisia gigantifolia extra...Objective:To evaluate the effects of ethanol extract from Ardisia gigantifolia leaves on cell proliferation and cancer stem cell(CSC)number in gastric cancer.Methods:The inhibitory effect of Ardisia gigantifolia extract on the proliferation of MKN45 and MKN74 gastric cancer cells was assessed using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay.Non-adherent culture(3D)model was used to evaluate the effect of the extract on tumorsphere size and number.Moreover,the expression of CD44,ALDH,and p21 was determined by immunofluorescence analysis.Flow cytometric analysis was performed to evaluate cell cycle arrest and the expression of gastric CSC markers CD44 and ALDH.Real-time PCR analysis was also carried out to assess the effect of the extract on the expression of cell cycle-regulated genes.Results:Ardisia gigantifolia extract effectively inhibited cell proliferation with an IC_(50)of 55.7μg/m L in MKN45 cells and 123.6μg/m L in MKN74 cells.The extract also arrested cell cycle in the G_(0)/G_(1)phase as well as significantly reduced the size and number of tumorspheres.The markedly increased expression of p21 was observed at both m RNA and protein levels in the extract-treated adherent cells and tumorspheres.In addition,Ardisia gigantifolia extract significantly reduced the number of CD44-and/or ALDH-expressing gastric CSC.Conclusions:The development of gastric CSC can be inhibited by the ethanol extract of Ardisia gigantifolia.展开更多
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-a...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.展开更多
Gastrointestinal cancer has been one of the five most commonly diagnosed and leading causes of cancer mortality over the past few decades. Great progress in traditional therapies has been made, which prolonged surviva...Gastrointestinal cancer has been one of the five most commonly diagnosed and leading causes of cancer mortality over the past few decades. Great progress in traditional therapies has been made, which prolonged survival in patients with early cancer, yet tumor relapse and drug resistance still occurred, which is explained by the cancer stem cell(CSC) theory. Oncolytic virotherapy has attracted increasing interest in cancer because of its ability to infect and lyse CSCs. This paper reviews the basic knowledge, CSC markers and therapeutics of gastrointestinal cancer(liver, gastric, colon and pancreatic cancer), as well as research advances and possible molecular mechanisms of various oncolytic viruses against gastrointestinal CSCs. This paper also summarizes the existing obstacles to oncolytic virotherapy and proposes several alternative suggestions to overcome the therapeutic limitations.展开更多
This study examined the effect of Notch-1 signaling on malignant behaviors of breast cancer cells by regulating breast cancer stem cells (BCSCs). BCSCs were enriched by using serum-free me- dium and knocked out of N...This study examined the effect of Notch-1 signaling on malignant behaviors of breast cancer cells by regulating breast cancer stem cells (BCSCs). BCSCs were enriched by using serum-free me- dium and knocked out of Notch-1 by using a lentiviral vector. Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to detect the Notch-1 expression levels in breast cancer cell lines and BCSCs, and fl0w cytometry to detect the proportion of BCSCs in BCSC spheres. The BCSC self-renewal, migration, invasion, and tumorigenicity were examined by the tumor microsphere-forming assay and transwell assay and after xenotransplantation. The results showed that the Notch-1 silencing reduced the number of BCSC spheres, the proportion of BCSCs, and the number of cells penetrating through the transwell membrane. It also decreased the size of tumors that were implanted in the nude mice. These results suggest that Notch-1 signaling is intimately linked to the behaviors of BCSCs. Blocking Notch-1 signaling can inhibit the malignant behaviors of BCSCs, which may provide a prom- ising therapeutical approach for breast cancer.展开更多
The cancer stem cells(CSCs)from human osteosarcoma by serum-free three-dimensional culture combined with anticancer drugs were isolated and identified.The primary cells derived from human osteosarcoma were digested by...The cancer stem cells(CSCs)from human osteosarcoma by serum-free three-dimensional culture combined with anticancer drugs were isolated and identified.The primary cells derived from human osteosarcoma were digested by trypsin to prepare a single-cell suspension,and mixed homogeneously into 1.2% alginate gel.Single-cell alginate gel was cultured with serum-free DMEM/F12 medium.Epirubicin(0.8μg/mL)was added to the medium to enrich CSCs.After cultured conventionally for 7 to 10 days,most of cells suspended in ...展开更多
It has been demonstrated that even localized tumors withottt chnically apparent metastasis give rise to circulating tumor cells (CTCs). A growing number of technically diverse platforms are being developed for detec...It has been demonstrated that even localized tumors withottt chnically apparent metastasis give rise to circulating tumor cells (CTCs). A growing number of technically diverse platforms are being developed for detecting/isolating CTCs in the circulating blood. Despite the technical challenges of isolating rare CTCs from blood, recent studies have already shown the predictive value of CTCs enumeration. Thus, it is becoming increasingly accepted that CTC numbers are linked to patients' outcome and may also be used to monitor treatment response and disease relapse, respectively. Further CTCs provide a non-invasive source for tumor material, 'liquid biopsy', which is particularly important for patients, where no biopsy material can be obtained or where serial biopsies of the tumor, e.g., following treatment, are practically impossible. On the other hand the molecular and biological characterization of CTCs has still remained at a rather experimental stage. Future studies are necessary to define CTC heterogeneity to establish the crucial role of circulating cancer stem cells for driving metastasis, which represent a distinct subpopulation of CTCs that bear metastasis-initiating capabilities based on their sternness properties and invasiveness and thus are critical for the patients' clinical outcome. As compared to non-tumorigenic/metastatic bulk CTCs, circulating cancer stem cells may not only be capable of evading from the primary tumor, but also escape from immune surveillance, survive in the circulating blood and subsequently form metastases in distant organs. Thus, circulating cancer stem cells represent a subset of exclusively tumorigenic cancer stem cells characterized by their invasive characteristics and are potential therapeutic targets for preventing disease progression. To date, only a few original reports and reviews have been published focusing on circulating cancer stem cells. This review discusses the potential importance of isolating and characterizing these circulating cancer stem cells, but also highlights current technological limitations.展开更多
Background: Cancer stem cells(CSCs) accelerate the growth of hepatocellular carcinoma(HCC) residual after incomplete radiofrequency ablation(In-RFA). The present study aimed to detect the effects of In-RFA on stemness...Background: Cancer stem cells(CSCs) accelerate the growth of hepatocellular carcinoma(HCC) residual after incomplete radiofrequency ablation(In-RFA). The present study aimed to detect the effects of In-RFA on stemness transcription factors(STFs) expression which are important for the production and function of CSCs, and to find which STFs promote HCC stemness after In-RFA. Methods: HepG2 cells were used for in vitro and in vivo studies. Flow cytometry and sphere-formation assays were used to detect the level and function of CD133~+ CSCs in the models. PCR array and ELISA were applied to analyze the altered expression of 84 STFs in CD133~+ CSCs in two models. Specific lentiviral shRNA was used to knockdown STFs expression, followed by detecting In-RFA’s effects on the levels and function of CD133~+ CSCs. Results: In-RFA was identified to induce CD133~+ CSCs and increase their tumorigenesis ability in vitro and in vivo. The mRNA levels of 84 STFs in CD133~+ CSCs were detected by PCR array, showing that 15 and 22 STFs were up-regulated in two models, respectively. Meanwhile, the mRNA levels of seven common STFs were up-regulated in both models. ELISA assay demonstrated that only the protein of sex determining region Y-box 9(SOX9) was up-regulated in both models, the protein levels of the other 6 common STFs did not increase in both models. Finally, SOX9 was identified to play an important role in inducing, maintaining stemness and promoting tumorigenesis ability of CD133~+ CSCs in both models. Conclusion: In-RFA-induced SOX9 stimulates CD133~+ CSCs proliferation and increases their tumorigenesis ability, suggesting that SOX9 may be a good target for HCC treatment.展开更多
We sought to determine whether STAT3 mediated tamoxifen resistance of breast cancer stem cells in vitro.The capacities for mammosphere formation and STAT3 expression of CD44+CD24-/low MCF-7 and MCF-7 were observed.Th...We sought to determine whether STAT3 mediated tamoxifen resistance of breast cancer stem cells in vitro.The capacities for mammosphere formation and STAT3 expression of CD44+CD24-/low MCF-7 and MCF-7 were observed.The CD44+CD24-/low subpopulation ratio and its sensitivity to adriamycin were analyzed in MCF-7 and TAM resistant(TAM-R) cells.Cell cycle,apoptosis,STAT3 and phospho-STAT3 changes were observed af-ter treatment with tamoxifen.Small interference RNA-mediated knockdown of STAT3 in TAM-R cells was also performed.CD44+CD24-/low MCF-7 showed higher capacities for mammosphere formation and STAT3 expression than total MCF-7.The CD44+CD24-/low subpopulation was also upregulated in TAM-R cells with less sensitivity to adriamycin than MCF-7.Cell cycle changes,anti-apoptotic effects and STAT3 changes were also found.Mean-while,the knock-down of STAT3 in TAM-R resulted in an increase in sensitivity to tamoxifen.It is concluded that STAT3 plays an essential role in breast cancer stem cells,which correlated with tamoxifen resistance.展开更多
BACKGROUND Cellular metabolism regulates stemness in health and disease.A reduced redox state is essential for self-renewal of normal and cancer stem cells(CSCs).However,while stem cells rely on glycolysis,different C...BACKGROUND Cellular metabolism regulates stemness in health and disease.A reduced redox state is essential for self-renewal of normal and cancer stem cells(CSCs).However,while stem cells rely on glycolysis,different CSCs,including pancreatic CSCs,favor mitochondrial metabolism as their dominant energy-producing pathway.This suggests that powerful antioxidant networks must be in place to detoxify mitochondrial reactive oxygen species(ROS)and maintain stemness in oxidative CSCs.Since glutathione metabolism is critical for normal stem cell function and CSCs from breast,liver and gastric cancer show increased glutathione content,we hypothesized that pancreatic CSCs also rely on this pathway for ROS detoxification.AIM To investigate the role of glutathione metabolism in pancreatic CSCs.METHODS Primary pancreatic cancer cells of patient-derived xenografts(PDXs)were cultured in adherent or CSC-enriching sphere conditions to determine the role of glutathione metabolism in stemness.Real-time polymerase chain reaction(PCR)was used to validate RNAseq results involving glutathione metabolism genes in adherent vs spheres,as well as the expression of pluripotency-related genes following treatment.Public TCGA and GTEx RNAseq data from pancreatic cancer vs normal tissue samples were analyzed using the webserver GEPIA2.The glutathione-sensitive fluorescent probe monochlorobimane was used to determine glutathione content by fluorimetry or flow cytometry.Pharmacological inhibitors of glutathione synthesis and recycling[buthionine-sulfoximine(BSO)and 6-Aminonicotinamide(6-AN),respectively]were used to investigate the impact of glutathione depletion on CSC-enriched cultures.Staining with propidium iodide(cell cycle),Annexin-V(apoptosis)and CD133(CSC content)were determined by flow cytometry.Self-renewal was assessed by sphere formation assay and response to gemcitabine treatment was used as a readout for chemoresistance.RESULTS Analysis of our previously published RNAseq dataset E-MTAB-3808 revealed upregulation of genes involved in the KEGG(Kyoto Encyclopedia of Genes and Genomes)Pathway Glutathione Metabolism in CSC-enriched cultures compared to their differentiated counterparts.Consistently,in pancreatic cancer patient samples the expression of most of these up-regulated genes positively correlated with a stemness signature defined by NANOG,KLF4,SOX2 and OCT4 expression(P<10-5).Moreover,3 of the upregulated genes(MGST1,GPX8,GCCT)were associated with reduced disease-free survival in patients[Hazard ratio(HR)2.2-2.5;P=0.03-0.0054],suggesting a critical role for this pathway in pancreatic cancer progression.CSC-enriched sphere cultures also showed increased expression of different glutathione metabolism-related genes,as well as enhanced glutathione content in its reduced form(GSH).Glutathione depletion with BSO induced cell cycle arrest and apoptosis in spheres,and diminished the expression of stemness genes.Moreover,treatment with either BSO or the glutathione recycling inhibitor 6-AN inhibited self-renewal and the expression of the CSC marker CD133.GSH content in spheres positively correlated with intrinsic resistance to gemcitabine treatment in different PDXs r=0.96,P=5.8×1011).Additionally,CD133+cells accumulated GSH in response to gemcitabine,which was abrogated by BSO treatment(P<0.05).Combined treatment with BSO and gemcitabine-induced apoptosis in CD133+cells to levels comparable to CD133-cells and significantly diminished self-renewal(P<0.05),suggesting that chemoresistance of CSCs is partially dependent on GSH metabolism.CONCLUSION Our data suggest that pancreatic CSCs depend on glutathione metabolism.Pharmacological targeting of this pathway showed that high GSH content is essential to maintain CSC functionality in terms of self-renewal and chemoresistance.展开更多
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 d...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.展开更多
基金the National Natural Science Foundation of China,No.82074402the Science and Technology Innovation Project of China Academy of Chinese Medical Sciences,No.CI2021A01802.
文摘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.
基金Natural Science Foundation of Anhui Province(No.1908085MH258)Scientific Research and Innovation Project of Bengbu Medical College(No.Byycxz21004)。
文摘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.
基金supported by the Natural Science Foundation of Hubei Province(no.2021CFB372 to Hua Xiong).
文摘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.
基金supported by the Department of Biotechnology(DBT),Govt of Indiasupported by the Council of Scientific and Industrial Research(CSIR),Govt.of India+1 种基金supported by the University Grants Commission(UGC),Govt.of Indiapartly supported by BT/INF/22/SP42155/2021 from the Department of Biotechnology,Ministry of Science and Technology,Govt.of India。
文摘Prostate cancer, one of the most frequently occurring cancers in men, is a heterogeneous disease involving multiple cell types within tumors. This tumor heterogeneity at least partly results from genomic instability leading to sub-clonal cellular differentiation. The differentiated cell populations originate from a small subset of cells with tumor-initiating and stem-like properties. These cells, termed prostate cancer stem cells(PCSCs), play crucial roles in disease progression, drug resistance, and relapse. This review discusses the origin, hierarchy, and plasticity of PCSCs;methods for isolation and enrichment of PCSCs;and various cellular and metabolic signaling pathways involved in PCSC induction and maintenance, as well as therapeutic targeting.
基金Natural Science Foundation of Nanjing University of Chinese Medicine China,No.XZR2020093.
文摘Cancer stem cells(CSCs)are a small proportion of the cells that exist in cancer tissues.They are considered to be the culprit of tumor genesis,development,drug resistance,metastasis and recurrence because of their self-renewal,proliferation,and differentiation potential.The elimination of CSCs is thus the key to cure cancer,and targeting CSCs provides a new method for tumor treatment.Due to the advantages of controlled sustained release,targeting and high biocompatibility,a variety of nanomaterials are used in the diagnosis and treatments targeting CSCs and promote the recognition and removal of tumor cells and CSCs.This article mainly reviews the research progress of nanotechnology in sorting CSCs and nanodrug delivery systems targeting CSCs.Furthermore,we identify the problems and future research directions of nanotechnology in CSC therapy.We hope that this review will provide guidance for the design of nanotechnology as a drug carrier so that it can be used in clinic for cancer therapy as soon as possible.
基金supported by the National Key Research and Development Program of China (Grant No.2023YFC3402100)the National Natural Science Foundation of China (Grant No.92259102)。
文摘Cancer stem cells(CSCs) are a small subset of cells in cancers that are thought to initiate tumorous transformation and promote metastasis, recurrence, and resistance to treatment. Growing evidence has revealed the existence of CSCs in various types of cancers and suggested that CSCs differentiate into diverse lineage cells that contribute to tumor progression. We may be able to overcome the limitations of cancer treatment with a comprehensive understanding of the biological features and mechanisms underlying therapeutic resistance in CSCs. This review provides an overview of the properties, biomarkers, and mechanisms of resistance shown by CSCs. Recent findings on metabolic features, especially fatty acid metabolism and ferroptosis in CSCs, are highlighted, along with promising targeting strategies. Targeting CSCs is a potential treatment plan to conquer cancer and prevent resistance and relapse in cancer treatment.
基金supported by grants from National Natural Science Foundation of China(Grant No.11832008)the Natural Scienceof Chongqing(Grant No.cstc2020jcyj-msxm X0545)the Japan Society for the Promotion of Science under grants-in-Aid for Scientific Research(S)(Grant No.17H06146)。
文摘Over the past 2 decades,cancer stem cells(CSCs)have been identified as the root cause of cancer occurrence,progression,chemoradioresistance,recurrence,and metastasis.Targeting CSCs is a novel therapeutic strategy for cancer management and treatment.Liver cancer(LC)is a malignant disease that can endanger human health.Studies are increasingly suggesting that changes in the liver mechanical microenvironment are a primary driver triggering the occurrence and development of liver cancer.In this review,we summarize current understanding of the roles of the liver mechano-microenvironment and liver cancer stem cells(LCSCs)in liver cancer progression.We also discuss the relationship between the mechanical heterogeneity of liver cancer tissues and LCSC recruitment and metastasis.Finally,we highlight potential mechanosensitive molecules in LCSCs and mechanotherapy in liver cancer.Understanding the roles and regulatory mechanisms of the mechano-microenvironment and LCSCs may provide fundamental insights into liver cancer progression and aid in further development of novel therapeutic strategies.
基金Supported by the Youth Medical Talent of Jiangsu Province,No.QNRC2016475.
文摘Cancer stem cells(CSCs)are the main cause of tumor growth,invasion,metastasis and recurrence.Recently,CSCs have been extensively studied to identify CSCspecific surface markers as well as signaling pathways that play key roles in CSCs self-renewal.The involvement of CSCs in the pathogenesis of gastrointestinal(GI)cancers also highlights these cells as a priority target for therapy.The diagnosis,prognosis and treatment of GI cancer have always been a focus of attention.Therefore,the potential application of CSCs in GI cancers is receiving increasing attention.This review summarizes the role of CSCs in GI cancers,focusing on esophageal cancer,gastric cancer,liver cancer,colorectal cancer,and pancreatic cancer.In addition,we propose CSCs as potential targets and therapeutic strategies for the effective treatment of GI cancers,which may provide better guidance for clinical treatment of GI cancers.
文摘Obesity,the global pandemic since industrialization,is the number one lifestylerelated risk factor for premature death,which increases the incidence and mortality of various diseases and conditions,including cancer.In recent years,the theory of cancer stem cells(CSCs),which have the capacity for self-renewal,metastasis and treatment resistance,has been bolstered by increasing evidence.However,research on how obesity affects CSCs to facilitate cancer initiation,progression and therapy resistance is still in its infancy,although evidence has already begun to accumulate.Regarding the ever-increasing burden of obesity and obesity-related cancer,it is pertinent to summarize evidence about the effects of obesity on CSCs,as elucidating these effects will contribute to the improvement in the management of obesity-related cancers.In this review,we discuss the association between obesity and CSCs,with a particular focus on how obesity promotes cancer initiation,progression and therapy resistance through CSCs and the mechanisms underlying these effects.In addition,the prospect of preventing cancer and targeting the mechanisms linking obesity and CSCs to reduce cancer risk or to improve the survival of patients with cancer is considered.
基金supported by ACTREC PhD fellowshipfunded by TMC-IRB (3542)ACTREC annual funds。
文摘Head and neck squamous cell carcinoma is the seventh most common cancer worldwide with high mortality rates.Amongst oral cavity cancers,tongue carcinoma is a very common and aggressive oral cavity carcinoma.Despite the implementation of a multimodality treatment regime including surgical intervention,chemo-radiation as well as targeted therapy,tongue carcinoma shows a poor overall 5-year survival pattern,which is attributed to therapy resistance and recurrence of the disease.The presence of a rare population,i.e.,cancer stem cells(CSCs)within the tumor,are involved in therapy resistance,recurrence,and distant metastasis that results in poor survival patterns.Therapeutic agents targeting CSCs have been in clinical trials,although they are unable to reach into therapy stage which is due to their failure in trials.A more detailed understanding of the CSCs is essential for identifying efficient targets.Molecular signaling pathways,which are differentially regulated in the CSCs,are one of the promising targets to manipulate the CSCs that would provide an improved outcome.In this review,we summarize the current understanding of molecular signaling associated with the maintenance and regulation of CSCs in tongue squamous cell carcinoma in order to emphasize the need of the hour to get a deeper understanding to unravel novel targets.
基金funded by Vietnam National Foundation for Science and Technology Development(NAFOSTED)under grant number 108.05-2017.331。
文摘Objective:To evaluate the effects of ethanol extract from Ardisia gigantifolia leaves on cell proliferation and cancer stem cell(CSC)number in gastric cancer.Methods:The inhibitory effect of Ardisia gigantifolia extract on the proliferation of MKN45 and MKN74 gastric cancer cells was assessed using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay.Non-adherent culture(3D)model was used to evaluate the effect of the extract on tumorsphere size and number.Moreover,the expression of CD44,ALDH,and p21 was determined by immunofluorescence analysis.Flow cytometric analysis was performed to evaluate cell cycle arrest and the expression of gastric CSC markers CD44 and ALDH.Real-time PCR analysis was also carried out to assess the effect of the extract on the expression of cell cycle-regulated genes.Results:Ardisia gigantifolia extract effectively inhibited cell proliferation with an IC_(50)of 55.7μg/m L in MKN45 cells and 123.6μg/m L in MKN74 cells.The extract also arrested cell cycle in the G_(0)/G_(1)phase as well as significantly reduced the size and number of tumorspheres.The markedly increased expression of p21 was observed at both m RNA and protein levels in the extract-treated adherent cells and tumorspheres.In addition,Ardisia gigantifolia extract significantly reduced the number of CD44-and/or ALDH-expressing gastric CSC.Conclusions:The development of gastric CSC can be inhibited by the ethanol extract of Ardisia gigantifolia.
基金Supported by UNAM-PAPIIT,No.IN219719 and No.IA205421CONACYT,No.A1-S-18285.
文摘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.
基金Supported by the National Natural Science Foundation of China,No.81272687the Natural Science Foundation of Zhejiang Province of China,No.LZ13H160004 and No.LY16H160056the 521 Talent Project of Zhejiang Sci-Tech University
文摘Gastrointestinal cancer has been one of the five most commonly diagnosed and leading causes of cancer mortality over the past few decades. Great progress in traditional therapies has been made, which prolonged survival in patients with early cancer, yet tumor relapse and drug resistance still occurred, which is explained by the cancer stem cell(CSC) theory. Oncolytic virotherapy has attracted increasing interest in cancer because of its ability to infect and lyse CSCs. This paper reviews the basic knowledge, CSC markers and therapeutics of gastrointestinal cancer(liver, gastric, colon and pancreatic cancer), as well as research advances and possible molecular mechanisms of various oncolytic viruses against gastrointestinal CSCs. This paper also summarizes the existing obstacles to oncolytic virotherapy and proposes several alternative suggestions to overcome the therapeutic limitations.
基金supported by the National Nature Science Foundation of China(No.30972935)
文摘This study examined the effect of Notch-1 signaling on malignant behaviors of breast cancer cells by regulating breast cancer stem cells (BCSCs). BCSCs were enriched by using serum-free me- dium and knocked out of Notch-1 by using a lentiviral vector. Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to detect the Notch-1 expression levels in breast cancer cell lines and BCSCs, and fl0w cytometry to detect the proportion of BCSCs in BCSC spheres. The BCSC self-renewal, migration, invasion, and tumorigenicity were examined by the tumor microsphere-forming assay and transwell assay and after xenotransplantation. The results showed that the Notch-1 silencing reduced the number of BCSC spheres, the proportion of BCSCs, and the number of cells penetrating through the transwell membrane. It also decreased the size of tumors that were implanted in the nude mice. These results suggest that Notch-1 signaling is intimately linked to the behaviors of BCSCs. Blocking Notch-1 signaling can inhibit the malignant behaviors of BCSCs, which may provide a prom- ising therapeutical approach for breast cancer.
文摘The cancer stem cells(CSCs)from human osteosarcoma by serum-free three-dimensional culture combined with anticancer drugs were isolated and identified.The primary cells derived from human osteosarcoma were digested by trypsin to prepare a single-cell suspension,and mixed homogeneously into 1.2% alginate gel.Single-cell alginate gel was cultured with serum-free DMEM/F12 medium.Epirubicin(0.8μg/mL)was added to the medium to enrich CSCs.After cultured conventionally for 7 to 10 days,most of cells suspended in ...
基金supported by an ERC Advanced Investigator Grant(Pa-CSC 233460)the European Community's Seventh Framework Programme(FP7/20072013) under grant agreement n° 256974(EPC-TM-NET) and n° 602783(CAM-PaC)+2 种基金the Subdireccion General de Evaluacion y Fomento de la Investigacion,Fondo de Investigacion Sanitaria(PS09/02129 & PI12/02643)the Programa Nacional de Internacionalizacion de la I+D, Subprogramma:FCCI 2009[PLE2009-0105both Ministerio de Economia y Competitividad(es),Spain],awarded to C.H.
文摘It has been demonstrated that even localized tumors withottt chnically apparent metastasis give rise to circulating tumor cells (CTCs). A growing number of technically diverse platforms are being developed for detecting/isolating CTCs in the circulating blood. Despite the technical challenges of isolating rare CTCs from blood, recent studies have already shown the predictive value of CTCs enumeration. Thus, it is becoming increasingly accepted that CTC numbers are linked to patients' outcome and may also be used to monitor treatment response and disease relapse, respectively. Further CTCs provide a non-invasive source for tumor material, 'liquid biopsy', which is particularly important for patients, where no biopsy material can be obtained or where serial biopsies of the tumor, e.g., following treatment, are practically impossible. On the other hand the molecular and biological characterization of CTCs has still remained at a rather experimental stage. Future studies are necessary to define CTC heterogeneity to establish the crucial role of circulating cancer stem cells for driving metastasis, which represent a distinct subpopulation of CTCs that bear metastasis-initiating capabilities based on their sternness properties and invasiveness and thus are critical for the patients' clinical outcome. As compared to non-tumorigenic/metastatic bulk CTCs, circulating cancer stem cells may not only be capable of evading from the primary tumor, but also escape from immune surveillance, survive in the circulating blood and subsequently form metastases in distant organs. Thus, circulating cancer stem cells represent a subset of exclusively tumorigenic cancer stem cells characterized by their invasive characteristics and are potential therapeutic targets for preventing disease progression. To date, only a few original reports and reviews have been published focusing on circulating cancer stem cells. This review discusses the potential importance of isolating and characterizing these circulating cancer stem cells, but also highlights current technological limitations.
基金supported by a grant from National Natural Science Foundation of China(81371546 and 61527807)Beijing Training Project For The Leading Talents in S&T(Z141107001514002)+4 种基金Health Industry Special Scientific Research Project(201402019)Beijing Municipal Administration of Hospitals’ Mission Plan(SML20150101)Beijing Scholar 2015(160)Capital Health Research and Development of Special Fund(2018-2-2182)the Beijing Municipal Science&Technology Commission(Z181100001718070)
文摘Background: Cancer stem cells(CSCs) accelerate the growth of hepatocellular carcinoma(HCC) residual after incomplete radiofrequency ablation(In-RFA). The present study aimed to detect the effects of In-RFA on stemness transcription factors(STFs) expression which are important for the production and function of CSCs, and to find which STFs promote HCC stemness after In-RFA. Methods: HepG2 cells were used for in vitro and in vivo studies. Flow cytometry and sphere-formation assays were used to detect the level and function of CD133~+ CSCs in the models. PCR array and ELISA were applied to analyze the altered expression of 84 STFs in CD133~+ CSCs in two models. Specific lentiviral shRNA was used to knockdown STFs expression, followed by detecting In-RFA’s effects on the levels and function of CD133~+ CSCs. Results: In-RFA was identified to induce CD133~+ CSCs and increase their tumorigenesis ability in vitro and in vivo. The mRNA levels of 84 STFs in CD133~+ CSCs were detected by PCR array, showing that 15 and 22 STFs were up-regulated in two models, respectively. Meanwhile, the mRNA levels of seven common STFs were up-regulated in both models. ELISA assay demonstrated that only the protein of sex determining region Y-box 9(SOX9) was up-regulated in both models, the protein levels of the other 6 common STFs did not increase in both models. Finally, SOX9 was identified to play an important role in inducing, maintaining stemness and promoting tumorigenesis ability of CD133~+ CSCs in both models. Conclusion: In-RFA-induced SOX9 stimulates CD133~+ CSCs proliferation and increases their tumorigenesis ability, suggesting that SOX9 may be a good target for HCC treatment.
文摘We sought to determine whether STAT3 mediated tamoxifen resistance of breast cancer stem cells in vitro.The capacities for mammosphere formation and STAT3 expression of CD44+CD24-/low MCF-7 and MCF-7 were observed.The CD44+CD24-/low subpopulation ratio and its sensitivity to adriamycin were analyzed in MCF-7 and TAM resistant(TAM-R) cells.Cell cycle,apoptosis,STAT3 and phospho-STAT3 changes were observed af-ter treatment with tamoxifen.Small interference RNA-mediated knockdown of STAT3 in TAM-R cells was also performed.CD44+CD24-/low MCF-7 showed higher capacities for mammosphere formation and STAT3 expression than total MCF-7.The CD44+CD24-/low subpopulation was also upregulated in TAM-R cells with less sensitivity to adriamycin than MCF-7.Cell cycle changes,anti-apoptotic effects and STAT3 changes were also found.Mean-while,the knock-down of STAT3 in TAM-R resulted in an increase in sensitivity to tamoxifen.It is concluded that STAT3 plays an essential role in breast cancer stem cells,which correlated with tamoxifen resistance.
文摘BACKGROUND Cellular metabolism regulates stemness in health and disease.A reduced redox state is essential for self-renewal of normal and cancer stem cells(CSCs).However,while stem cells rely on glycolysis,different CSCs,including pancreatic CSCs,favor mitochondrial metabolism as their dominant energy-producing pathway.This suggests that powerful antioxidant networks must be in place to detoxify mitochondrial reactive oxygen species(ROS)and maintain stemness in oxidative CSCs.Since glutathione metabolism is critical for normal stem cell function and CSCs from breast,liver and gastric cancer show increased glutathione content,we hypothesized that pancreatic CSCs also rely on this pathway for ROS detoxification.AIM To investigate the role of glutathione metabolism in pancreatic CSCs.METHODS Primary pancreatic cancer cells of patient-derived xenografts(PDXs)were cultured in adherent or CSC-enriching sphere conditions to determine the role of glutathione metabolism in stemness.Real-time polymerase chain reaction(PCR)was used to validate RNAseq results involving glutathione metabolism genes in adherent vs spheres,as well as the expression of pluripotency-related genes following treatment.Public TCGA and GTEx RNAseq data from pancreatic cancer vs normal tissue samples were analyzed using the webserver GEPIA2.The glutathione-sensitive fluorescent probe monochlorobimane was used to determine glutathione content by fluorimetry or flow cytometry.Pharmacological inhibitors of glutathione synthesis and recycling[buthionine-sulfoximine(BSO)and 6-Aminonicotinamide(6-AN),respectively]were used to investigate the impact of glutathione depletion on CSC-enriched cultures.Staining with propidium iodide(cell cycle),Annexin-V(apoptosis)and CD133(CSC content)were determined by flow cytometry.Self-renewal was assessed by sphere formation assay and response to gemcitabine treatment was used as a readout for chemoresistance.RESULTS Analysis of our previously published RNAseq dataset E-MTAB-3808 revealed upregulation of genes involved in the KEGG(Kyoto Encyclopedia of Genes and Genomes)Pathway Glutathione Metabolism in CSC-enriched cultures compared to their differentiated counterparts.Consistently,in pancreatic cancer patient samples the expression of most of these up-regulated genes positively correlated with a stemness signature defined by NANOG,KLF4,SOX2 and OCT4 expression(P<10-5).Moreover,3 of the upregulated genes(MGST1,GPX8,GCCT)were associated with reduced disease-free survival in patients[Hazard ratio(HR)2.2-2.5;P=0.03-0.0054],suggesting a critical role for this pathway in pancreatic cancer progression.CSC-enriched sphere cultures also showed increased expression of different glutathione metabolism-related genes,as well as enhanced glutathione content in its reduced form(GSH).Glutathione depletion with BSO induced cell cycle arrest and apoptosis in spheres,and diminished the expression of stemness genes.Moreover,treatment with either BSO or the glutathione recycling inhibitor 6-AN inhibited self-renewal and the expression of the CSC marker CD133.GSH content in spheres positively correlated with intrinsic resistance to gemcitabine treatment in different PDXs r=0.96,P=5.8×1011).Additionally,CD133+cells accumulated GSH in response to gemcitabine,which was abrogated by BSO treatment(P<0.05).Combined treatment with BSO and gemcitabine-induced apoptosis in CD133+cells to levels comparable to CD133-cells and significantly diminished self-renewal(P<0.05),suggesting that chemoresistance of CSCs is partially dependent on GSH metabolism.CONCLUSION Our data suggest that pancreatic CSCs depend on glutathione metabolism.Pharmacological targeting of this pathway showed that high GSH content is essential to maintain CSC functionality in terms of self-renewal and chemoresistance.
文摘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.