Drug resistance remains a major challenge in breast cancer chemotherapy,yet the metabolic alterations underlying this phenomenon are not fully understood.There is much evidence indicating the cellular heterogeneity am...Drug resistance remains a major challenge in breast cancer chemotherapy,yet the metabolic alterations underlying this phenomenon are not fully understood.There is much evidence indicating the cellular heterogeneity among cancer cells,which exhibit varying degrees of metabolic reprogramming and thus may result in differential contributions to drug resistance.A home-built single-cell quantitative mass spectrometry(MS)platform,which integrates micromanipulation and electro-osmotic sampling,was developed to quantitatively profile the tricarboxylic acid(TCA)cycle metabolites at the single-cell level.Using this platform,the metabolic profiles of drug-sensitive MCF-7 breast cancer cells and their drug-resistant derivative MCF-7/ADR cells were compared.This results revealed a selective upregulation of downstream TCA cycle metabolites includingα-ketoglutarate,succinate,fumarate,and malate in drug-resistant cancer cells,while early TCA metabolites remained largely unchanged.Furthermore,notable variations in the abundance of the metabolites were observed in individual cells.The comparative analysis also revealed that not all MCF-7/ADR cells exhibit the same degree of metabolic deviation from the parental line in the metabolites during resistance acquisition.The observed metabolic profiles indicate enhanced glutaminolysis,altered mitochondrial electron transport chain activity,and increased metabolic flexibility in drug-resistant cancer cells that support their survival under chemotherapeutic stress.The findings further suggest the potential for incorporating cellular metabolic heterogeneity into future drug resistance studies.展开更多
Cancer stem cells(CSCs)represent a distinct subpopulation of cells characterized by self-renewal capacity,differentiation potential,and critical roles in driving tumor progression,therapeutic resistance,recurrence,and...Cancer stem cells(CSCs)represent a distinct subpopulation of cells characterized by self-renewal capacity,differentiation potential,and critical roles in driving tumor progression,therapeutic resistance,recurrence,and maintenance of the tumor microenvironment.Targeting CSCs has emerged as a pivotal direction in cancer research,offering novel strategies to overcome drug resistance and prevent metastasis and relapse.Lysosomes,traditionally recognized as central organelles for intracellular degradation and recycling,are indispensable for cellular homeostasis.Dysregulation of lysosomal function is intimately linked to various diseases,including cancer.In tumors,aberrant lysosomal activity can promote malignant progression through mechanisms such as altering metabolic pathways,enhancing lysosomal exocytosis,modulating drug resistance,and interfering with autophagy-lysosomal pathways.Recent studies have underscored the involvement of lysosomes in regulating CSC properties.This review synthesizes findings on lysosomal regulation of CSCs through the following aspects.(1)Lysosomes exert complex and critical bidirectional control over CSC stemness maintenance through three degradation pathways that are dependent on their degradative function.(i)The lysophagy pathway.This pathway exhibits dual roles.Activation can sustain CSC functions;for instance,in glioblastoma,hypoxia upregulates Gal-8 via the STAT3/HIF1αsignaling axis to induce autophagy,supporting stem cell survival.In head and neck squamous cell carcinoma,degradation of GSK3βactivates the Wnt pathway,enhancing stemness.Conversely,this pathway can suppress stemness by degrading stemness-related proteins such as BMI-1 and OCT4A,thereby impairing CSC selfrenewal capacity.(ii)Mitophagy pathway.In non-small cell lung cancer stem cells,mitophagy-related mechanisms,such as the accumulation of mitochondrial DNA(mtDNA)activating the TLR9-Notch1-AMPK signaling axis,have been shown to promote CSC proliferation.(iii)Autophagosome-dependent lysosomal degradation pathway.This pathway directly regulates stemness-related proteins in a bidirectional manner.Enhanced degradative function can promote CSC properties,exemplified by the degradation of NUMB to activate Notch signaling.Conversely,attenuated degradative function can also enhance stemness by stabilizing oncoproteins(e.g.,protecting Frizzled-1 from degradation to sustain Wnt signaling)or preventing the degradation of tumor suppressors(e.g.,inhibiting Notch degradation).(2)Constituent proteins of lysosomes,including membrane proteins and luminal acid hydrolases,participate in regulating CSC stemness.Regarding membrane proteins,LAMP2A facilitates chaperone-mediated autophagy to maintain stemness in glioblastoma and ovarian cancer.V-ATPase,by maintaining an acidic luminal environment,promotes proliferation and drug resistance in glioma stem cells.Among hydrolases,cathepsins B and L are highly expressed in pancreatic and ovarian cancers and correlate with poor prognosis.Furthermore,targeting lysosomes to induce lysosomal membrane permeabilization(LMP)triggers lysosome-mediated cell death,presenting a potential therapeutic strategy for eradicating CSCs.(3)The acidic luminal environment,single-membrane structure,and the presence of transmembrane transporters(e.g.,ABCA3)enable lysosomes to passively trap or actively uptake and sequester chemotherapeutic drugs.Subsequent drug extrusion via exocytosis confers drug resistance.In CSCs,this lysosome-mediated drug sequestration,often cooperating with autophagy,establishes multimodal drug resistance.Therefore,targeting lysosomal function represents a potential strategy to overcome therapy resistance.The central role of lysosomes in regulating CSC stemness and resistance positions them as highly promising therapeutic targets.Strategies aimed at disrupting lysosomal function to selectively eliminate CSCs include:inhibiting the lysosome-autophagy system using agents like IITZ or lovastatin;inducing lysosomal membrane permeabilization(LMP)with compounds such as hexamethylene amiloride to compromise membrane stability;and disrupting the acidic luminal environment using drugs like siramesine or the K/H transport compound 2.In conclusion,lysosomes critically regulate CSC stemness maintenance and drug resistance through degradative pathways,membrane protein functions,luminal hydrolase activities,and drug sequestration mechanisms.This redefines the lysosome from a traditional“waste disposal unit”to a“signal integration center”in CSCs.The duality and context-dependency of lysosomal function in CSCs offer novel insights into the heterogeneity observed across different tumors.Targeting lysosomal vulnerabilities—such as inducing LMP,disrupting acidity,or blocking autophagic flux—provides a strategy to bypass canonical CSC resistance mechanisms and directly trigger cell death.This establishes the lysosome as a key target to overcome CSC-mediated therapy resistance,paving the way for developing diverse candidate drugs and innovative combination therapies in oncology.展开更多
By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the r...By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the resistance to ciprofloxacin hydrochloride, enrofloxacin, ofloxacin, pefloacin mesylate and norfloxacin nicotinate of the five types of fluoroquinolones to GyrA mutation of animal Salmonella, the resistance of pefloacin mesylate had the most significant effect, while the resistance of ciprofloxacin hydrochloride and enrofloxacin were the least significant factors. Nearly half of the Salmonella supports such a rule that the MIC of norfloxacin nicotinate reaching 64 or 128 might lead to the mutation Ser83→Phe, MIC exceeding 512 might lead to the mutation Ser83→Gly; 60% of the sample supported that the MIC of enrofloxacin reaching 32 or 64 might lead to the mutation Asp87 →Asn. 80% of them agreed to the fact that the MIC of neither ciprofloxacin hydrochloride under 64 nor pefloacin mesylate below 512 might result in the gene mutation in 119 site. All Salmonella isolates supported the conclusion that the mutation Alal19→Val took place, if and only if the MIC of norfloxacin nicotinate exceeded 512.展开更多
基金supported by National Natural Science Foundation of China(22374080,22174068,21722504)Primary Research&Development Plan of Jiangsu Province(BK20221303,BE2022796)+1 种基金Open Foundation of State Key Laboratory of Reproductive Medicine(SKLRM-2022BP1,JX116GSP20240507)Science and Technology Development Fund of NJMU(NJMUQY2022003)。
文摘Drug resistance remains a major challenge in breast cancer chemotherapy,yet the metabolic alterations underlying this phenomenon are not fully understood.There is much evidence indicating the cellular heterogeneity among cancer cells,which exhibit varying degrees of metabolic reprogramming and thus may result in differential contributions to drug resistance.A home-built single-cell quantitative mass spectrometry(MS)platform,which integrates micromanipulation and electro-osmotic sampling,was developed to quantitatively profile the tricarboxylic acid(TCA)cycle metabolites at the single-cell level.Using this platform,the metabolic profiles of drug-sensitive MCF-7 breast cancer cells and their drug-resistant derivative MCF-7/ADR cells were compared.This results revealed a selective upregulation of downstream TCA cycle metabolites includingα-ketoglutarate,succinate,fumarate,and malate in drug-resistant cancer cells,while early TCA metabolites remained largely unchanged.Furthermore,notable variations in the abundance of the metabolites were observed in individual cells.The comparative analysis also revealed that not all MCF-7/ADR cells exhibit the same degree of metabolic deviation from the parental line in the metabolites during resistance acquisition.The observed metabolic profiles indicate enhanced glutaminolysis,altered mitochondrial electron transport chain activity,and increased metabolic flexibility in drug-resistant cancer cells that support their survival under chemotherapeutic stress.The findings further suggest the potential for incorporating cellular metabolic heterogeneity into future drug resistance studies.
文摘Cancer stem cells(CSCs)represent a distinct subpopulation of cells characterized by self-renewal capacity,differentiation potential,and critical roles in driving tumor progression,therapeutic resistance,recurrence,and maintenance of the tumor microenvironment.Targeting CSCs has emerged as a pivotal direction in cancer research,offering novel strategies to overcome drug resistance and prevent metastasis and relapse.Lysosomes,traditionally recognized as central organelles for intracellular degradation and recycling,are indispensable for cellular homeostasis.Dysregulation of lysosomal function is intimately linked to various diseases,including cancer.In tumors,aberrant lysosomal activity can promote malignant progression through mechanisms such as altering metabolic pathways,enhancing lysosomal exocytosis,modulating drug resistance,and interfering with autophagy-lysosomal pathways.Recent studies have underscored the involvement of lysosomes in regulating CSC properties.This review synthesizes findings on lysosomal regulation of CSCs through the following aspects.(1)Lysosomes exert complex and critical bidirectional control over CSC stemness maintenance through three degradation pathways that are dependent on their degradative function.(i)The lysophagy pathway.This pathway exhibits dual roles.Activation can sustain CSC functions;for instance,in glioblastoma,hypoxia upregulates Gal-8 via the STAT3/HIF1αsignaling axis to induce autophagy,supporting stem cell survival.In head and neck squamous cell carcinoma,degradation of GSK3βactivates the Wnt pathway,enhancing stemness.Conversely,this pathway can suppress stemness by degrading stemness-related proteins such as BMI-1 and OCT4A,thereby impairing CSC selfrenewal capacity.(ii)Mitophagy pathway.In non-small cell lung cancer stem cells,mitophagy-related mechanisms,such as the accumulation of mitochondrial DNA(mtDNA)activating the TLR9-Notch1-AMPK signaling axis,have been shown to promote CSC proliferation.(iii)Autophagosome-dependent lysosomal degradation pathway.This pathway directly regulates stemness-related proteins in a bidirectional manner.Enhanced degradative function can promote CSC properties,exemplified by the degradation of NUMB to activate Notch signaling.Conversely,attenuated degradative function can also enhance stemness by stabilizing oncoproteins(e.g.,protecting Frizzled-1 from degradation to sustain Wnt signaling)or preventing the degradation of tumor suppressors(e.g.,inhibiting Notch degradation).(2)Constituent proteins of lysosomes,including membrane proteins and luminal acid hydrolases,participate in regulating CSC stemness.Regarding membrane proteins,LAMP2A facilitates chaperone-mediated autophagy to maintain stemness in glioblastoma and ovarian cancer.V-ATPase,by maintaining an acidic luminal environment,promotes proliferation and drug resistance in glioma stem cells.Among hydrolases,cathepsins B and L are highly expressed in pancreatic and ovarian cancers and correlate with poor prognosis.Furthermore,targeting lysosomes to induce lysosomal membrane permeabilization(LMP)triggers lysosome-mediated cell death,presenting a potential therapeutic strategy for eradicating CSCs.(3)The acidic luminal environment,single-membrane structure,and the presence of transmembrane transporters(e.g.,ABCA3)enable lysosomes to passively trap or actively uptake and sequester chemotherapeutic drugs.Subsequent drug extrusion via exocytosis confers drug resistance.In CSCs,this lysosome-mediated drug sequestration,often cooperating with autophagy,establishes multimodal drug resistance.Therefore,targeting lysosomal function represents a potential strategy to overcome therapy resistance.The central role of lysosomes in regulating CSC stemness and resistance positions them as highly promising therapeutic targets.Strategies aimed at disrupting lysosomal function to selectively eliminate CSCs include:inhibiting the lysosome-autophagy system using agents like IITZ or lovastatin;inducing lysosomal membrane permeabilization(LMP)with compounds such as hexamethylene amiloride to compromise membrane stability;and disrupting the acidic luminal environment using drugs like siramesine or the K/H transport compound 2.In conclusion,lysosomes critically regulate CSC stemness maintenance and drug resistance through degradative pathways,membrane protein functions,luminal hydrolase activities,and drug sequestration mechanisms.This redefines the lysosome from a traditional“waste disposal unit”to a“signal integration center”in CSCs.The duality and context-dependency of lysosomal function in CSCs offer novel insights into the heterogeneity observed across different tumors.Targeting lysosomal vulnerabilities—such as inducing LMP,disrupting acidity,or blocking autophagic flux—provides a strategy to bypass canonical CSC resistance mechanisms and directly trigger cell death.This establishes the lysosome as a key target to overcome CSC-mediated therapy resistance,paving the way for developing diverse candidate drugs and innovative combination therapies in oncology.
基金Supported by the National Natural Science Foundation of China (11171244)
文摘By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the resistance to ciprofloxacin hydrochloride, enrofloxacin, ofloxacin, pefloacin mesylate and norfloxacin nicotinate of the five types of fluoroquinolones to GyrA mutation of animal Salmonella, the resistance of pefloacin mesylate had the most significant effect, while the resistance of ciprofloxacin hydrochloride and enrofloxacin were the least significant factors. Nearly half of the Salmonella supports such a rule that the MIC of norfloxacin nicotinate reaching 64 or 128 might lead to the mutation Ser83→Phe, MIC exceeding 512 might lead to the mutation Ser83→Gly; 60% of the sample supported that the MIC of enrofloxacin reaching 32 or 64 might lead to the mutation Asp87 →Asn. 80% of them agreed to the fact that the MIC of neither ciprofloxacin hydrochloride under 64 nor pefloacin mesylate below 512 might result in the gene mutation in 119 site. All Salmonella isolates supported the conclusion that the mutation Alal19→Val took place, if and only if the MIC of norfloxacin nicotinate exceeded 512.
