Background:Triple-negative breast cancer(TNBC),characterized by its lack of traditional hormone receptors and HER2,presents a significant challenge in oncology due to its poor response to conventional therapies.Autoph...Background:Triple-negative breast cancer(TNBC),characterized by its lack of traditional hormone receptors and HER2,presents a significant challenge in oncology due to its poor response to conventional therapies.Autophagy is an important process for maintaining cellular homeostasis,and there are currently autophagy biomarkers that play an effective role in the clinical treatment of tumors.In contrast to targeting protein activity,intervention with proteinprotein interaction(PPI)can avoid unrelated crosstalk and regulate the autophagy process with minimal interference pathways.Methods:Here,we employed Naive Bayes,Decision Tree,and k-Nearest Neighbors to elucidate the complex PPI network associated with autophagy in TNBC,aiming to uncover novel therapeutic targets.Meanwhile,the candidate proteins interacting with Beclin 2 were initially screened in MDA-MB-231 cells using Beclin 2 as bait protein by immunoprecipitation-mass spectrometry assay,and the interaction relationship was verified by molecular docking and CO-IP experiments after intersection.Colony formation,cellular immunofluorescence,cell scratch and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)tests were used to predict the clinical therapeutic effects of manipulating candidate PPI.Results:By developing three PPI classification models and analyzing over 13,000 datasets,we identified 3733 previously unknown autophagy-related PPIs.Our network analysis revealed the central role of Beclin 2 in autophagy regulation,uncovering its interactions with 39 newly identified proteins.Notably,the CO-IP studies identified the substantial interaction between Beclin 2 and Ubiquilin 1,which was anticipated by our model and discovered in immunoprecipitation-mass spectrometry assay results.Subsequently,in vitro investigations showed that overexpressing Beclin 2 increased Ubiquilin 1,promoted autophagy-dependent cell death,and inhibited proliferation and metastasis in MDA-MB-231 cells.Conclusions:This study not only enhances our understanding of autophagy regulation in TNBC but also identifies the Beclin 2-Ubiquilin 1 axis as a promising target for precision therapy.These findings open new avenues for drug discovery and offer inspiration for more effective treatments for this aggressive cancer subtype.展开更多
The crosstalk between megakaryocytic lineage cells and the skeletal system has just begun to be explored but remains largely elusive.Using conditional gene knockout mouse models,we demonstrated that loss of Beclin 1(B...The crosstalk between megakaryocytic lineage cells and the skeletal system has just begun to be explored but remains largely elusive.Using conditional gene knockout mouse models,we demonstrated that loss of Beclin 1(Becn1),a major regulator of mammalian autophagy,exclusively in the megakaryocytic lineage disrupted autophagy in platelets but did not compromise megakaryopoiesis or the formation and function of platelets.Unexpectedly,conditional Becn1 deletion in male mice led to a remarkable increase in bone mass with improved bone quality,in association with a decrease in sex hormone binding globulin(SHBG)and an increase in free testosterone(FT).In vivo Becn1 overexpression in megakaryocytic lineage-specific cells reduced bone mass and quality,along with an increase in SHBG and a decrease in FT.Transplantation of wild-type bone marrow cells into megakaryocytic lineage Becn1-deficient male mice restored bone mass and normalized SHBG and FT.Furthermore,bilateral orchiectomy of Becn1^(f/f);Pf4-iCre mice,which are crippled with the production of testosterone,resulted in a reduction in bone mass and quality,whereas in vivo overexpression of SHBG,specifically in the liver of Becn1^(f/f);Pf4-iCre mice,decreased FT and reduced bone mass and quality.In addition,metformin treatment,which induces SHBG expression,reduced FT and normalized bone mass in Becn1^(f/f);Pf4-iCre mice.We thus concluded that Becn1 of the megakaryocytic lineage is dispensable locally for platelet hemostasis but limits bone mass by increasing SHBG,which in turn reduces the FT of male mice.Our findings highlight a mechanism by which Becn1 from megakaryocytic lineage cells distally balances bone growth.展开更多
基金the National Natural Science Foundation of China(Nos.22307009,82374155,82073997,82104376)the Sichuan Science and Technology Program(Nos.2023NSFSC1108,2024NSFTD0023)+1 种基金the Postdoctoral Research Project of Sichuan Provincethe Xinglin Scholar Research Promotion Project of Chengdu University of TCM.
文摘Background:Triple-negative breast cancer(TNBC),characterized by its lack of traditional hormone receptors and HER2,presents a significant challenge in oncology due to its poor response to conventional therapies.Autophagy is an important process for maintaining cellular homeostasis,and there are currently autophagy biomarkers that play an effective role in the clinical treatment of tumors.In contrast to targeting protein activity,intervention with proteinprotein interaction(PPI)can avoid unrelated crosstalk and regulate the autophagy process with minimal interference pathways.Methods:Here,we employed Naive Bayes,Decision Tree,and k-Nearest Neighbors to elucidate the complex PPI network associated with autophagy in TNBC,aiming to uncover novel therapeutic targets.Meanwhile,the candidate proteins interacting with Beclin 2 were initially screened in MDA-MB-231 cells using Beclin 2 as bait protein by immunoprecipitation-mass spectrometry assay,and the interaction relationship was verified by molecular docking and CO-IP experiments after intersection.Colony formation,cellular immunofluorescence,cell scratch and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)tests were used to predict the clinical therapeutic effects of manipulating candidate PPI.Results:By developing three PPI classification models and analyzing over 13,000 datasets,we identified 3733 previously unknown autophagy-related PPIs.Our network analysis revealed the central role of Beclin 2 in autophagy regulation,uncovering its interactions with 39 newly identified proteins.Notably,the CO-IP studies identified the substantial interaction between Beclin 2 and Ubiquilin 1,which was anticipated by our model and discovered in immunoprecipitation-mass spectrometry assay results.Subsequently,in vitro investigations showed that overexpressing Beclin 2 increased Ubiquilin 1,promoted autophagy-dependent cell death,and inhibited proliferation and metastasis in MDA-MB-231 cells.Conclusions:This study not only enhances our understanding of autophagy regulation in TNBC but also identifies the Beclin 2-Ubiquilin 1 axis as a promising target for precision therapy.These findings open new avenues for drug discovery and offer inspiration for more effective treatments for this aggressive cancer subtype.
基金supported in part by grants from the National Natural Science Foundation of China(No.81673093,No.82170227,No.91649113,No.82470165,No.82000121,No.31771640)the Jiangsu Science and Technology Department(No.SBK20200191)+1 种基金the State Key Laboratory of Radiation Medicine and Protection of Soochow University(No.GZC00201)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘The crosstalk between megakaryocytic lineage cells and the skeletal system has just begun to be explored but remains largely elusive.Using conditional gene knockout mouse models,we demonstrated that loss of Beclin 1(Becn1),a major regulator of mammalian autophagy,exclusively in the megakaryocytic lineage disrupted autophagy in platelets but did not compromise megakaryopoiesis or the formation and function of platelets.Unexpectedly,conditional Becn1 deletion in male mice led to a remarkable increase in bone mass with improved bone quality,in association with a decrease in sex hormone binding globulin(SHBG)and an increase in free testosterone(FT).In vivo Becn1 overexpression in megakaryocytic lineage-specific cells reduced bone mass and quality,along with an increase in SHBG and a decrease in FT.Transplantation of wild-type bone marrow cells into megakaryocytic lineage Becn1-deficient male mice restored bone mass and normalized SHBG and FT.Furthermore,bilateral orchiectomy of Becn1^(f/f);Pf4-iCre mice,which are crippled with the production of testosterone,resulted in a reduction in bone mass and quality,whereas in vivo overexpression of SHBG,specifically in the liver of Becn1^(f/f);Pf4-iCre mice,decreased FT and reduced bone mass and quality.In addition,metformin treatment,which induces SHBG expression,reduced FT and normalized bone mass in Becn1^(f/f);Pf4-iCre mice.We thus concluded that Becn1 of the megakaryocytic lineage is dispensable locally for platelet hemostasis but limits bone mass by increasing SHBG,which in turn reduces the FT of male mice.Our findings highlight a mechanism by which Becn1 from megakaryocytic lineage cells distally balances bone growth.
