Aim Recent evidence has revealed that Eukaryotic elongation factor-2 kinase （eEF2K） activity may confer cancer cell adaptation to metabolic stress, and high expression of eEF2K is found in several types of cancer. T...Aim Recent evidence has revealed that Eukaryotic elongation factor-2 kinase （eEF2K） activity may confer cancer cell adaptation to metabolic stress, and high expression of eEF2K is found in several types of cancer. Therefore, eEF2K may contribute to carcinogenesis and represent a promising therapeutic target; however, inhibi- tion of eEF2K for cancer drug discovery still remains in its infancy. This study aimed at developing a series of eEF2K inhibitor as candidate anti-tumor drugs in breast cancer and illustrating the possible mechanisms of its anti- tumor activity in vitro and in vivo. Methods In silico screening, structure modifications, MTT assay and molecular dynamics （MD） simulations were applied for the discovery of the novel eEF2K inhibitor （BL-EKI03）. Observa- tions of cell morphology were executed through several methods including ER-traeker, MDC and Hoeehst 33258 staining and GFP-LC3 transfeetion. Flow eytometrie analyses of MDC and Annexin V/PI were used for quantifica- tion of autophagy and apoptosis ratio. Western blot and ITRAQ analysis were used to explore the detailed mecha- nisms of BL-EKI03-induced ER stress, autophagie death and apoptosis in breast cancer cells. Furthermore, an in vivo xenograft mouse model was established for validating the anti-tumor efficacy of BL-EKI03. Results Firstly, a novel eEF2K inhibitor （BL-EKI03） with a good affinity for eEF2K was eventually discovered after computational screening and synthesis of a series of candidate compounds targeting eEF2K. Subsequently, our results demonstra- ted that BL-EKI03 has remarkable anti-proliferative activities and induces endoplasmie retieulum （ER） stress, au- tophagy and apoptosis in MCF-7 and MDA-MB-436 cells. More importantly, the mechanism for BL-EKI03-indueed autophagie death involves eEF2K-mediated AMPK-mTOR-ULK complex pathways. The proteomies analyses and ex-perimental validation revealed that the BL-EKI03-induced mechanism was also involved BIRC6, BNIP1, SNAP29 and Bif-1, which might be regulated by eEF2K. Moreover, BL-EKI03 exerted its anti-tumor activities without re- markable toxicity, and it also induced autophagy and apoptosis by targeting eEF2K in fifo. Conclusion In this study, a novel eEF2K inhibitor （BL-EKI03） was discovered with remarkable anti-proliferative activities and in- duced endoplasmic reticulum （ER） stress, autophagy and apoptosis of breast cancer in vitro and in fifo. These findings highlight a new small-molecule eEF2K inhibitor （BL-EKI03） that has the potential to impact future breast cancer therapy.展开更多
[Objectives] To study the therapeutic effect and mechanism of New Maixian Powder on ulcerative colitis( UC) rats through observing its regulatory effect on the protein kinase R-like endoplasmic reticulum kinase( PERK)...[Objectives] To study the therapeutic effect and mechanism of New Maixian Powder on ulcerative colitis( UC) rats through observing its regulatory effect on the protein kinase R-like endoplasmic reticulum kinase( PERK)/eukaryotic translation initiation factor-2α( e IF-2α)/nuclear transcription factor-kappa B( NF-κB) signaling pathway. [Methods]First,60 SD rats were randomly divided into normal group,model group,mesalazine group,and New Maixian Powder low,medium and high dose groups,10 rats each group. Then,dextran sulfate sodium( DSS) was used to induce UC rats. The mesalazine group was given 0. 42 g/( kg·d) of mesalazine sustained-release granule suspension,New Maixian Powder low,medium and high dose groups were given 1. 5,3,and 6 g/( kg·d) of New Maixian Powder suspension,respectively,and other groups were given an equal volume of physiological saline,continuous intragastric administration for 14 d. Next,the disease activity index( DAI) of UC rats was evaluated; the expression of NF-κB in serum was measured by enzyme-linked immunosorbent assay( ELISA); the expression of PERK and e IF-2α protein and m RNA in colon tissue was detected by Western blot and real-time quantitative polymerase chain reaction( RT q-PCR). [Results] Compared with the normal group,the DAI score and serum NF-κB level in the model group were significantly higher( P < 0. 05),and PERK and e IF-2α protein and m RNA levels in the colon tissue were increased( P < 0. 05); compared with the model group,the DAI score decreased and serum NF-κB level declined in the New Maixian Powder group,and the expression of PERK and e IF-2α protein and m RNA in New Maixian Powder medium dose and high dose groups declined( P < 0. 05). [Conclusions]New Maixian Powder has good therapeutic effect on UC rats,and its mechanism may be connected with the inhibition of the activation of PERK/e IF-2α/NF-κB signaling pathway.展开更多
Background:Tumor metastasis is a major factor for poor prognosis of hepatocellular carcinoma(HCC),but the relationship between ubiquitination and metastasis need to be studiedmore systematically.We analyzed the ubiqui...Background:Tumor metastasis is a major factor for poor prognosis of hepatocellular carcinoma(HCC),but the relationship between ubiquitination and metastasis need to be studiedmore systematically.We analyzed the ubiquitinome of HCC in this study to have a more comprehensive insight into human HCC metastasis.Methods:The protein ubiquitination levels in 15 HCC specimens with vascular invasion and 15 without vascular invasion were detected by ubiquitinome.Proteins with significantly different ubiquitination levels between HCCs with and without vascular invasion were used to predict E3 ubiquitin ligases associated with tumor metastasis.The topological network of protein substrates and corresponding E3 ubiquitin ligaseswas constructed to identify the key E3 ubiquitin ligase.Besides,the growth,migration and invasion ability of LM3 and HUH7 hepatoma cell lines with andwithout SYVN1 expression interferencewere measured by cell proliferation assay,subcutaneous tumor assay,umphal vein endothelium tube formation assay,transwell migration and invasion assays.Finally,the interacting proteins of SYVN1 were screened and verified by protein interaction omics,immunofluorescence,and immunoprecipitation.Ubiquitin levels of related protein substrates in LM3 and HUH7 cells were compared in negative control,SYVN1 knockdown,and SYVN1 overexpression groups.Results:In this study,our whole-cell proteomic dataset and ubiquitinomic dataset contained approximately 5600 proteins and 12,000 ubiquitinated sites.We discovered increased ubiquitinated sites with shorter ubiquitin chains during the progression ofHCC metastasis.In addition,proteomic and ubiquitinomic analyses revealed that high expression of E3 ubiquitin-protein ligase SYVN1 is related with tumor metastasis.Furthermore,we found that SYVN1 interacted with heat shock protein 90(HSP90)and impacted the ubiquitination of eukaryotic elongation factor 2 kinase(EEF2K).Conclusions:The ubiquitination profiles of HCC with and without vascular invasion were significantly different.SYVN1 was the most important E3 ubiquitin-protein ligase responsible for this phenomenon,and itwas related with tumormetastasis and growth.Therefore,SYVN1might be a potential therapeutic target for HCC.展开更多
文摘Aim Recent evidence has revealed that Eukaryotic elongation factor-2 kinase （eEF2K） activity may confer cancer cell adaptation to metabolic stress, and high expression of eEF2K is found in several types of cancer. Therefore, eEF2K may contribute to carcinogenesis and represent a promising therapeutic target; however, inhibi- tion of eEF2K for cancer drug discovery still remains in its infancy. This study aimed at developing a series of eEF2K inhibitor as candidate anti-tumor drugs in breast cancer and illustrating the possible mechanisms of its anti- tumor activity in vitro and in vivo. Methods In silico screening, structure modifications, MTT assay and molecular dynamics （MD） simulations were applied for the discovery of the novel eEF2K inhibitor （BL-EKI03）. Observa- tions of cell morphology were executed through several methods including ER-traeker, MDC and Hoeehst 33258 staining and GFP-LC3 transfeetion. Flow eytometrie analyses of MDC and Annexin V/PI were used for quantifica- tion of autophagy and apoptosis ratio. Western blot and ITRAQ analysis were used to explore the detailed mecha- nisms of BL-EKI03-induced ER stress, autophagie death and apoptosis in breast cancer cells. Furthermore, an in vivo xenograft mouse model was established for validating the anti-tumor efficacy of BL-EKI03. Results Firstly, a novel eEF2K inhibitor （BL-EKI03） with a good affinity for eEF2K was eventually discovered after computational screening and synthesis of a series of candidate compounds targeting eEF2K. Subsequently, our results demonstra- ted that BL-EKI03 has remarkable anti-proliferative activities and induces endoplasmie retieulum （ER） stress, au- tophagy and apoptosis in MCF-7 and MDA-MB-436 cells. More importantly, the mechanism for BL-EKI03-indueed autophagie death involves eEF2K-mediated AMPK-mTOR-ULK complex pathways. The proteomies analyses and ex-perimental validation revealed that the BL-EKI03-induced mechanism was also involved BIRC6, BNIP1, SNAP29 and Bif-1, which might be regulated by eEF2K. Moreover, BL-EKI03 exerted its anti-tumor activities without re- markable toxicity, and it also induced autophagy and apoptosis by targeting eEF2K in fifo. Conclusion In this study, a novel eEF2K inhibitor （BL-EKI03） was discovered with remarkable anti-proliferative activities and in- duced endoplasmic reticulum （ER） stress, autophagy and apoptosis of breast cancer in vitro and in fifo. These findings highlight a new small-molecule eEF2K inhibitor （BL-EKI03） that has the potential to impact future breast cancer therapy.
基金Supported by Science and Technology Program of Zhejiang Province(2016C33085)
文摘[Objectives] To study the therapeutic effect and mechanism of New Maixian Powder on ulcerative colitis( UC) rats through observing its regulatory effect on the protein kinase R-like endoplasmic reticulum kinase( PERK)/eukaryotic translation initiation factor-2α( e IF-2α)/nuclear transcription factor-kappa B( NF-κB) signaling pathway. [Methods]First,60 SD rats were randomly divided into normal group,model group,mesalazine group,and New Maixian Powder low,medium and high dose groups,10 rats each group. Then,dextran sulfate sodium( DSS) was used to induce UC rats. The mesalazine group was given 0. 42 g/( kg·d) of mesalazine sustained-release granule suspension,New Maixian Powder low,medium and high dose groups were given 1. 5,3,and 6 g/( kg·d) of New Maixian Powder suspension,respectively,and other groups were given an equal volume of physiological saline,continuous intragastric administration for 14 d. Next,the disease activity index( DAI) of UC rats was evaluated; the expression of NF-κB in serum was measured by enzyme-linked immunosorbent assay( ELISA); the expression of PERK and e IF-2α protein and m RNA in colon tissue was detected by Western blot and real-time quantitative polymerase chain reaction( RT q-PCR). [Results] Compared with the normal group,the DAI score and serum NF-κB level in the model group were significantly higher( P < 0. 05),and PERK and e IF-2α protein and m RNA levels in the colon tissue were increased( P < 0. 05); compared with the model group,the DAI score decreased and serum NF-κB level declined in the New Maixian Powder group,and the expression of PERK and e IF-2α protein and m RNA in New Maixian Powder medium dose and high dose groups declined( P < 0. 05). [Conclusions]New Maixian Powder has good therapeutic effect on UC rats,and its mechanism may be connected with the inhibition of the activation of PERK/e IF-2α/NF-κB signaling pathway.
基金National Key Research and Development Program,Grant/Award Number:2017YFC1200100National Natural Science Foundation of China,Grant/Award Number:81400589Chinese National Science and Technology Major Project of the 13th Five-year plan,Grant/Award Number:2017ZX10202202-001-008。
文摘Background:Tumor metastasis is a major factor for poor prognosis of hepatocellular carcinoma(HCC),but the relationship between ubiquitination and metastasis need to be studiedmore systematically.We analyzed the ubiquitinome of HCC in this study to have a more comprehensive insight into human HCC metastasis.Methods:The protein ubiquitination levels in 15 HCC specimens with vascular invasion and 15 without vascular invasion were detected by ubiquitinome.Proteins with significantly different ubiquitination levels between HCCs with and without vascular invasion were used to predict E3 ubiquitin ligases associated with tumor metastasis.The topological network of protein substrates and corresponding E3 ubiquitin ligaseswas constructed to identify the key E3 ubiquitin ligase.Besides,the growth,migration and invasion ability of LM3 and HUH7 hepatoma cell lines with andwithout SYVN1 expression interferencewere measured by cell proliferation assay,subcutaneous tumor assay,umphal vein endothelium tube formation assay,transwell migration and invasion assays.Finally,the interacting proteins of SYVN1 were screened and verified by protein interaction omics,immunofluorescence,and immunoprecipitation.Ubiquitin levels of related protein substrates in LM3 and HUH7 cells were compared in negative control,SYVN1 knockdown,and SYVN1 overexpression groups.Results:In this study,our whole-cell proteomic dataset and ubiquitinomic dataset contained approximately 5600 proteins and 12,000 ubiquitinated sites.We discovered increased ubiquitinated sites with shorter ubiquitin chains during the progression ofHCC metastasis.In addition,proteomic and ubiquitinomic analyses revealed that high expression of E3 ubiquitin-protein ligase SYVN1 is related with tumor metastasis.Furthermore,we found that SYVN1 interacted with heat shock protein 90(HSP90)and impacted the ubiquitination of eukaryotic elongation factor 2 kinase(EEF2K).Conclusions:The ubiquitination profiles of HCC with and without vascular invasion were significantly different.SYVN1 was the most important E3 ubiquitin-protein ligase responsible for this phenomenon,and itwas related with tumormetastasis and growth.Therefore,SYVN1might be a potential therapeutic target for HCC.
