Backgrounds:Breast cancer metastasis remains the leading cause of mortality and frequently targets the bone.Breast cancer cells release soluble factors and extracellular vesicles that disrupt bone marrow(BM)/bone home...Backgrounds:Breast cancer metastasis remains the leading cause of mortality and frequently targets the bone.Breast cancer cells release soluble factors and extracellular vesicles that disrupt bone marrow(BM)/bone homeostasis,promoting osteoclastogenesis and the accumulation of senescent cells.In line with updated cancer hallmarks,senescent mesenchymal stem/stromal cells(MSCs),osteoblasts,and osteocytes contribute to remodeling of the BM microenvironment,thereby favoring pre-metastatic niche(PMN)formation and subsequent bone metastasis.We previously demonstrated that untreated stage III-B breast cancer patients(BCPs)exhibit increased oxidative stress and elevated reactive oxygen species(ROS)levels,accompanied by senescent and functionally impaired BM-MSCs—key regulators of BM/bone homeostasis.In the present study,we sought to identify the molecular targets affected by oxidative stress that drive MSC senescence in these patients.Methods:BM-MSCs were isolated from untreated stage III-B BCPs and healthy volunteers(HVs).Oxidative stress responses were evaluated by quantitative real-time PCR(qRT-PCR)analysis of stress-and antioxidant-related genes.Oxidative damage to DNA,proteins,and lipids was assessed using alkaline comet assay,chromosomal aberration(CAs)analysis,micronuclei(MN)and nuclear blebs(NBs)quantification,protein carbonyl content,and detection of 4-hydroxynonenal(4-HNE)adducts.The MSC secretome was analyzed by label-free quantitative proteomics followed by Gene Ontology enrichment analysis.Results:Our results show that elevated oxidative stress in BCPs induces the overexpression of oxidative stress-related and antioxidant response genes in BM-MSCs;however,this response is insufficient to prevent extensive ROS-induced damage to deoxyribonucleic acid(DNA),proteins,and lipids.In addition,proteomic analysis of the BM-MSC secretome revealed a distinct protein expression profile in BCPs compared with HVs.Conclusions:Together,these findings highlight oxidative stress-induced MSC damage as a key mechanism contributing to PMN formation and suggest potential therapeutic targets to mitigate bone metastasis in advanced breast cancer.展开更多
Breast cancer is the predominant form of carcinoma among women worldwide,with 70%of advanced patients developing bone metastases,with a high mortality rate.In this sense,the bone marrow(BM)mesenchymal stem/stromal cel...Breast cancer is the predominant form of carcinoma among women worldwide,with 70%of advanced patients developing bone metastases,with a high mortality rate.In this sense,the bone marrow(BM)mesenchymal stem/stromal cells(MSCs)are critical for BM/bone homeostasis,and failures in their functionality,transform the BM into a premetastatic niche(PMN).We previously found that BM-MSCs from advanced breast cancer patients(BCPs,infiltrative ductal carcinoma,stage III-B)have an abnormal profile.This work aims to study some of the metabolic and molecular mechanisms underlying MSCs shift from a normal to an abnormal profile in this group of patients.A comparative analysis was undertaken,which included self-renewal capacity,morphology,proliferation capacity,cell cycle,reactive oxygen species(ROS)levels,and senescence-associatedβ‑galactosidase(SA‑β‑gal)staining of BMderived MSCs isolated from 14 BCPs and 9 healthy volunteers(HVs).Additionally,the expression and activity of the telomerase subunit TERT,as well as telomere length,were measured.Expression levels of pluripotency,osteogenic,and osteoclastogenic genes(OCT-4,SOX-2,M-CAM,RUNX-2,BMP-2,CCL-2,M-CSF,and IL-6)were also determined.The results showed that MSCs from BCPs had reduced,self-renewal and proliferation capacity.These cells also exhibited inhibited cell cycle progression and phenotypic changes,such as an enlarged and flattened appearance.Additionally,there was an increase in ROS and senescence levels and a decrease in the functional capacity of TERT to preserve telomere length.We also found an increase in pro-inflammatory/pro-osteoclastogenic gene expression and a decrease in pluripotency gene expression.We conclude that these changes could be responsible for the abnormal functional profile that MSCs show in this group of patients.展开更多
基金supported by the FONCYT,PICT 2016-#1093,Argentina.CONICET,PIP2014-#300,Argentina.Florencio Fiorini Foundation(#2021-2022),Argentina.
文摘Backgrounds:Breast cancer metastasis remains the leading cause of mortality and frequently targets the bone.Breast cancer cells release soluble factors and extracellular vesicles that disrupt bone marrow(BM)/bone homeostasis,promoting osteoclastogenesis and the accumulation of senescent cells.In line with updated cancer hallmarks,senescent mesenchymal stem/stromal cells(MSCs),osteoblasts,and osteocytes contribute to remodeling of the BM microenvironment,thereby favoring pre-metastatic niche(PMN)formation and subsequent bone metastasis.We previously demonstrated that untreated stage III-B breast cancer patients(BCPs)exhibit increased oxidative stress and elevated reactive oxygen species(ROS)levels,accompanied by senescent and functionally impaired BM-MSCs—key regulators of BM/bone homeostasis.In the present study,we sought to identify the molecular targets affected by oxidative stress that drive MSC senescence in these patients.Methods:BM-MSCs were isolated from untreated stage III-B BCPs and healthy volunteers(HVs).Oxidative stress responses were evaluated by quantitative real-time PCR(qRT-PCR)analysis of stress-and antioxidant-related genes.Oxidative damage to DNA,proteins,and lipids was assessed using alkaline comet assay,chromosomal aberration(CAs)analysis,micronuclei(MN)and nuclear blebs(NBs)quantification,protein carbonyl content,and detection of 4-hydroxynonenal(4-HNE)adducts.The MSC secretome was analyzed by label-free quantitative proteomics followed by Gene Ontology enrichment analysis.Results:Our results show that elevated oxidative stress in BCPs induces the overexpression of oxidative stress-related and antioxidant response genes in BM-MSCs;however,this response is insufficient to prevent extensive ROS-induced damage to deoxyribonucleic acid(DNA),proteins,and lipids.In addition,proteomic analysis of the BM-MSC secretome revealed a distinct protein expression profile in BCPs compared with HVs.Conclusions:Together,these findings highlight oxidative stress-induced MSC damage as a key mechanism contributing to PMN formation and suggest potential therapeutic targets to mitigate bone metastasis in advanced breast cancer.
基金Supported by the FONCYT,Argentina(PICT 2016-#1093)CONICET,Argentina(PIP2014-2016,#300)Fundación Florencio Fiorini(Subsidio 2021-2022),Argentina.
文摘Breast cancer is the predominant form of carcinoma among women worldwide,with 70%of advanced patients developing bone metastases,with a high mortality rate.In this sense,the bone marrow(BM)mesenchymal stem/stromal cells(MSCs)are critical for BM/bone homeostasis,and failures in their functionality,transform the BM into a premetastatic niche(PMN).We previously found that BM-MSCs from advanced breast cancer patients(BCPs,infiltrative ductal carcinoma,stage III-B)have an abnormal profile.This work aims to study some of the metabolic and molecular mechanisms underlying MSCs shift from a normal to an abnormal profile in this group of patients.A comparative analysis was undertaken,which included self-renewal capacity,morphology,proliferation capacity,cell cycle,reactive oxygen species(ROS)levels,and senescence-associatedβ‑galactosidase(SA‑β‑gal)staining of BMderived MSCs isolated from 14 BCPs and 9 healthy volunteers(HVs).Additionally,the expression and activity of the telomerase subunit TERT,as well as telomere length,were measured.Expression levels of pluripotency,osteogenic,and osteoclastogenic genes(OCT-4,SOX-2,M-CAM,RUNX-2,BMP-2,CCL-2,M-CSF,and IL-6)were also determined.The results showed that MSCs from BCPs had reduced,self-renewal and proliferation capacity.These cells also exhibited inhibited cell cycle progression and phenotypic changes,such as an enlarged and flattened appearance.Additionally,there was an increase in ROS and senescence levels and a decrease in the functional capacity of TERT to preserve telomere length.We also found an increase in pro-inflammatory/pro-osteoclastogenic gene expression and a decrease in pluripotency gene expression.We conclude that these changes could be responsible for the abnormal functional profile that MSCs show in this group of patients.
