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
Pancreatic cancer is one of the most aggressive cancers with a median survival time of less than 5 months,and conventional chemotherapeutics are the main treatment strategy.Poly(ADP-ribose)polymerase(PARP)inhibitors h...Pancreatic cancer is one of the most aggressive cancers with a median survival time of less than 5 months,and conventional chemotherapeutics are the main treatment strategy.Poly(ADP-ribose)polymerase(PARP)inhibitors have been recently approved for BRCA1/2-mutant pancreatic cancer,opening a new era for targeted therapy for this disease.However,most pancreatic cancer patients carry wild-type BRCA1/2 with resistance to PARP inhibitors.Here,we reported that mammalian target of rapamycin complex 2(mTORC2)kinase is overexpressed in pancreatic cancer tissues and promotes pancreatic cancer cell growth and invasion.Moreover,we found that knockdown of the mTORC2 obligate subunit Rictor sensitized pancreatic cancer cells to the PARP inhibitor olaparib.Mechanistically,we showed that mTORC2 positively regulates homologous recombination(HR)repair by modulating BRCA1 recruitment to DNA double-strand breaks(DSBs).In addition,we confirmed that combination treatment with the mTORC2 inhibitor PP242 and the PARP inhibitor olaparib synergistically inhibited pancreatic cancer growth in vivo.Thus,this study provides a novel target and strategy for optimizing PARP inhibitor efficiency in pancreatic cancers.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
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This work was supported by the National Natural Science Foundation of China(81572408)the Program of Medical Innovation Team and Leading Medical Talents in Jiangsu Province(2017ZXKJQW09).
文摘Pancreatic cancer is one of the most aggressive cancers with a median survival time of less than 5 months,and conventional chemotherapeutics are the main treatment strategy.Poly(ADP-ribose)polymerase(PARP)inhibitors have been recently approved for BRCA1/2-mutant pancreatic cancer,opening a new era for targeted therapy for this disease.However,most pancreatic cancer patients carry wild-type BRCA1/2 with resistance to PARP inhibitors.Here,we reported that mammalian target of rapamycin complex 2(mTORC2)kinase is overexpressed in pancreatic cancer tissues and promotes pancreatic cancer cell growth and invasion.Moreover,we found that knockdown of the mTORC2 obligate subunit Rictor sensitized pancreatic cancer cells to the PARP inhibitor olaparib.Mechanistically,we showed that mTORC2 positively regulates homologous recombination(HR)repair by modulating BRCA1 recruitment to DNA double-strand breaks(DSBs).In addition,we confirmed that combination treatment with the mTORC2 inhibitor PP242 and the PARP inhibitor olaparib synergistically inhibited pancreatic cancer growth in vivo.Thus,this study provides a novel target and strategy for optimizing PARP inhibitor efficiency in pancreatic cancers.
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.
