Background:Ossification of the posterior longitudinal ligament(OPLL)is a prevalent condition in orthopedics.While death-associated protein kinase 2(DAPK2)is known to play roles in cellular apoptosis and autophagy,its ...Background:Ossification of the posterior longitudinal ligament(OPLL)is a prevalent condition in orthopedics.While death-associated protein kinase 2(DAPK2)is known to play roles in cellular apoptosis and autophagy,its specific contributions to the advancement of OPLL are not well understood.Methods:Ligament fibroblasts were harvested from patients diagnosed with OPLL.Techniques such as real-time reverse transcriptasepolymerase chain reaction(RT-qPCR)and Western blot analysis were employed to assess DAPK2 levels in both ligament tissues and cultured fibroblasts.The extent of osteogenic differentiation in these cells was evaluated using an alizarin red S(ARS)staining.Additionally,the expression of ossification markers and autophagy markers was quantified.The autophagic activity was further analyzed through LC3 immunofluorescence and transmission electron microscopy(TEM).An in vivo heterotopic bone formation assay was conducted in mice to assess the role of DAPK2 in ossification.Results:Elevated DAPK2 expression was confirmed in both OPLL patient tissues and derived fibroblasts,in contrast to non-OPLL controls.Silencing of DAPK2 significantly curtailed osteogenic differentiation and autophagy in these fibroblasts,evidenced by decreased levels of LC3,and Beclin1,and reduced autophagosome formation.Additionally,DAPK2 was found to inhibit the mechanistic target of the rapamycin complex 1(mTORC1)complex’s activity.In vivo studies demonstrated that DAPK2 facilitates ossification,and this effect could be counteracted by the mTORC1 inhibitor rapamycin.Conclusion:DAPK2 enhances autophagy and osteogenic processes in OPLL through modulation of the mTORC1 pathway.展开更多
Glioblastoma （GBM） is one of the most lethal human cancers. Genomic analyses define the molecular architecture of GBM and highlight a central function for mechanistic target of rapamycin （roTOR） signaling, roTOR k...Glioblastoma （GBM） is one of the most lethal human cancers. Genomic analyses define the molecular architecture of GBM and highlight a central function for mechanistic target of rapamycin （roTOR） signaling, roTOR kinase exists in two multi- protein complexes, namely, mTORC 1 and mTORC2. These complexes differ in terms of function, regulation and rapamycin sensitivity, mTORC 1 is well established as a cancer drug target, whereas the functions of mTORC2 in cancer, including GBM, remains poorly understood. This study reviews the recent findings that demonstrate a central function ofmTORC2 in regulating tumor growth, metabolic reprogramming, and targeted therapy resistance in GBM, which makes mTORCZ as a critical GBM drug target.展开更多
Background:Sorafenib is an oral multi-kinase inhibitor that was approved by the US Food and Drug Administration for the treatment of patients with advanced hepatocellular carcinoma(HCC).However,resistance to sorafenib...Background:Sorafenib is an oral multi-kinase inhibitor that was approved by the US Food and Drug Administration for the treatment of patients with advanced hepatocellular carcinoma(HCC).However,resistance to sorafenib is an urgent problem to be resolved to improve the therapeutic efficacy of sorafenib.As the activation of AKT/mTOR played a pivotal role in sorafenib resistance,we evaluated the effect of a dual mTOR complex 1/2 inhibitor Torin2 on overcoming the sorafenib resistance in HCC cells.Methods:The sorafenib-resistant Huh7 and Hep3B cell lines were established from their parental cell lines.The synergistic effect of sorafenib and Torin2 on these cells was measured by cell viability assay and quantified using the Chou-Talalay method.Apoptosis induced by the combination of sorafenib and Torin2 and the alteration in the specific signaling pathways of interest were detected by Western blotting.Results:Sorafenib treatment inversely inhibited AKT in parental but activated AKT in sorafenib-resistant Huh7 and Hep3B HCC cells,which underscores the significance of AKT activation.Torin2 and sorafenib synergistically suppressed the viability of sorafenib-resistant cells via apoptosis induction.Torin2 successfully suppressed the sorafenib-activated mTORC2-AKT axis,leading to the dephosphorylation of Ser136 in BAD protein,and increased the expression of total BAD,which contributed to the apoptosis in sorafenibresistant HCC cells.Conclusions:In this study,Torin2 and sorafenib showed synergistic cytostatic capacity in sorafenibresistant HCC cells,via the suppression of mTORC2-AKT-BAD pathway.Our results suggest a novel strategy of drug combination for overcoming sorafenib resistance in HCC.展开更多
基金This research received funding from the Natural Science Foundation of Shanghai(Grant No.20ZR1457600)the School-Level Basic Medical Project of Naval Medical University(Grant No.2021MS13).
文摘Background:Ossification of the posterior longitudinal ligament(OPLL)is a prevalent condition in orthopedics.While death-associated protein kinase 2(DAPK2)is known to play roles in cellular apoptosis and autophagy,its specific contributions to the advancement of OPLL are not well understood.Methods:Ligament fibroblasts were harvested from patients diagnosed with OPLL.Techniques such as real-time reverse transcriptasepolymerase chain reaction(RT-qPCR)and Western blot analysis were employed to assess DAPK2 levels in both ligament tissues and cultured fibroblasts.The extent of osteogenic differentiation in these cells was evaluated using an alizarin red S(ARS)staining.Additionally,the expression of ossification markers and autophagy markers was quantified.The autophagic activity was further analyzed through LC3 immunofluorescence and transmission electron microscopy(TEM).An in vivo heterotopic bone formation assay was conducted in mice to assess the role of DAPK2 in ossification.Results:Elevated DAPK2 expression was confirmed in both OPLL patient tissues and derived fibroblasts,in contrast to non-OPLL controls.Silencing of DAPK2 significantly curtailed osteogenic differentiation and autophagy in these fibroblasts,evidenced by decreased levels of LC3,and Beclin1,and reduced autophagosome formation.Additionally,DAPK2 was found to inhibit the mechanistic target of the rapamycin complex 1(mTORC1)complex’s activity.In vivo studies demonstrated that DAPK2 facilitates ossification,and this effect could be counteracted by the mTORC1 inhibitor rapamycin.Conclusion:DAPK2 enhances autophagy and osteogenic processes in OPLL through modulation of the mTORC1 pathway.
基金supported by grants from the National Institute for Neurological Diseases and Stroke(NS73831)the National Cancer Institute(CA151819)+1 种基金The Ben and Catherine Ivy Foundation,the Defeat GBM Research Collaborative,a subsidiary of National Brain Tumor Societyby the generous donations from the Ziering Family Foundation in memory of Sigi Ziering
文摘Glioblastoma （GBM） is one of the most lethal human cancers. Genomic analyses define the molecular architecture of GBM and highlight a central function for mechanistic target of rapamycin （roTOR） signaling, roTOR kinase exists in two multi- protein complexes, namely, mTORC 1 and mTORC2. These complexes differ in terms of function, regulation and rapamycin sensitivity, mTORC 1 is well established as a cancer drug target, whereas the functions of mTORC2 in cancer, including GBM, remains poorly understood. This study reviews the recent findings that demonstrate a central function ofmTORC2 in regulating tumor growth, metabolic reprogramming, and targeted therapy resistance in GBM, which makes mTORCZ as a critical GBM drug target.
基金a grant from Medical and Health Science and Technology Program of Zhejiang Province(2019RC076).
文摘Background:Sorafenib is an oral multi-kinase inhibitor that was approved by the US Food and Drug Administration for the treatment of patients with advanced hepatocellular carcinoma(HCC).However,resistance to sorafenib is an urgent problem to be resolved to improve the therapeutic efficacy of sorafenib.As the activation of AKT/mTOR played a pivotal role in sorafenib resistance,we evaluated the effect of a dual mTOR complex 1/2 inhibitor Torin2 on overcoming the sorafenib resistance in HCC cells.Methods:The sorafenib-resistant Huh7 and Hep3B cell lines were established from their parental cell lines.The synergistic effect of sorafenib and Torin2 on these cells was measured by cell viability assay and quantified using the Chou-Talalay method.Apoptosis induced by the combination of sorafenib and Torin2 and the alteration in the specific signaling pathways of interest were detected by Western blotting.Results:Sorafenib treatment inversely inhibited AKT in parental but activated AKT in sorafenib-resistant Huh7 and Hep3B HCC cells,which underscores the significance of AKT activation.Torin2 and sorafenib synergistically suppressed the viability of sorafenib-resistant cells via apoptosis induction.Torin2 successfully suppressed the sorafenib-activated mTORC2-AKT axis,leading to the dephosphorylation of Ser136 in BAD protein,and increased the expression of total BAD,which contributed to the apoptosis in sorafenibresistant HCC cells.Conclusions:In this study,Torin2 and sorafenib showed synergistic cytostatic capacity in sorafenibresistant HCC cells,via the suppression of mTORC2-AKT-BAD pathway.Our results suggest a novel strategy of drug combination for overcoming sorafenib resistance in HCC.
