Hepatocellular carcinoma(HCC)is the most common primary liver malignancy and is the fourth-leading cause of cancer-related deaths worldwide.HCC is refractory to many standard cancer treatments and the prognosis is oft...Hepatocellular carcinoma(HCC)is the most common primary liver malignancy and is the fourth-leading cause of cancer-related deaths worldwide.HCC is refractory to many standard cancer treatments and the prognosis is often poor,highlighting a pressing need to identify biomarkers of aggressiveness and potential targets for future treatments.Kinesin family member 2C(KIF2C)is reported to be highly expressed in several human tumors.Nevertheless,the molecular mechanisms underlying the role of KIF2C in tumor development and progression have not been investigated.In this study,we found that KIF2C expression was significantly upregulated in HCC,and that KIF2C up-regulation was associated with a poor prognosis.Utilizing both gain and loss of function assays,we showed that KIF2C promoted HCC cell proliferation,migration,invasion,and metastasis both in vitro and in vivo.Mechanistically,we identified TBC1D7 as a binding partner of KIF2C,and this interaction disrupts the formation of the TSC complex,resulting in the enhancement of mammalian target of rapamycin complexl(mTORCI)signal transduction.Additionally,we found that KIF2C is a direct target of the Wnt/β-catenin pathway,and acts as a key factor in mediating the crosstalk between Wnt/β-catenin and mTORCI signaling.Thus,the results of our study establish a link between Wnt/β-catenin and mTORCI signaling,which highlights the potential of KIF2C as a therapeutic target for the treatment of HCC.展开更多
Dear Editor, mTORCI, as a center regulatory hub of metabolism, senses the cellular energy status, nutrition and extracellular stimuli and regulates cell growth, differentiation and functions of immune cells (Powell et...Dear Editor, mTORCI, as a center regulatory hub of metabolism, senses the cellular energy status, nutrition and extracellular stimuli and regulates cell growth, differentiation and functions of immune cells (Powell et al., 2012). Lysosomal localization of key signal comp orients is critical for mTORCI activati on: mTORCI activation requires co-localization of activated Rheb and mTORCI to the lysosome membrane (Buerger et al., 2006). Signals in eluding growth factors, cellular stresses and energy levels act on the disruption the formation of tuberous sclerosis complex (TSC) complex, comprised of TSC1, TSC2 and TBC1D7, which leads to the translocation and activation of Rheb on the lysosome membrane (Dibble et al., 2012). In response to nutrient levels, specifically the availability of amino acids and glucose (Efeyan et al., 2013), mTORCI is recruited to the lysosomal surface by Rag GTPases that are heterodimers of RagA or RagC bound to RagB or RagD. Multiple protein complexes have been implicated in regulation of mTORCI upon nutrient sensing including Ragulator, GATOR1, GATOR2, KICSTOR and vacuolar ATPases (Wolfson et al., 2017). Vacuolar ATPases are large multiple-protein complexes that acidify the lysosome and may mediate additional functions independent of their proton pump activity (Nishi and Forgac, 2002).展开更多
Recently, we have demonstrated the ability of naringin, a well-known flavanone glycoside of grapefruits and citrus fruits, to prevent neurodegeneration in a neurotoxin model of Parkinson＇s disease. Intraperitoneal in...Recently, we have demonstrated the ability of naringin, a well-known flavanone glycoside of grapefruits and citrus fruits, to prevent neurodegeneration in a neurotoxin model of Parkinson＇s disease. Intraperitoneal injection of naringin protected the nigrostriatal dopaminergic projection by increasing glial cell line-derived neurotrophic factor expression and decreasing the level of tumor necrosis factor-alpha in dopaminergic neurons and microglia, respectively. These results suggest that naringin can impart to the adult dopaminergic neurons the ability to produce glial cell line-derived neurotrophic factor against Parkinson＇s disease with anti-inflammatory effects. Based on these results, we would like to describe an important perspective on its possibility as a therapeutic agent for Parkinson＇s disease.展开更多
Mechanistic target of rapamycin complex 1(mTORCt)regulates CD8^(+)T-cell differentiation and function.Despite the links between PI3K-AKT and mTORCI activation in CD8^(+)T cells,the molecular mechanism underlying mTORC...Mechanistic target of rapamycin complex 1(mTORCt)regulates CD8^(+)T-cell differentiation and function.Despite the links between PI3K-AKT and mTORCI activation in CD8^(+)T cells,the molecular mechanism underlying mTORCI activation remains undear.Here,we show that both the kinase activity and the death domain of DAPK1 are required for maximal mTOR activation and CD8^(+)T-cell function.We found that TCR-induced activation of calcineurin activates DAPK1,which subsequently interacts with TSC2 via its death domain and phosphorylates TSC2 to mediate mTORCI activation.Furthermore,both the kinase domain and death domain of DAPK1 are required for CD8^(+)T-cell antiviral responses in an LCMV infection model.Together,our data reveal a novel mechanism of mTORCI activation that mediates optimal CD8^(+)T-cell function and antiviral activity.展开更多
基金This work was supported by the grants of the National Key R&D Program of China(2017YFC1309001)Guangzhou Science and Technology Plan Projects(Health Medical Collaborative Innovation Program of Guangzhou,201803040019)+3 种基金National Natural Science Foundation of China(81730072,81672407 and 81872001,81902411)Guangdong Natural Science Funds for Distinguished Young Scholar(No.2015A030306001)National Postdoctoral Program for Innovative Talents(BX201700299)China Postdoctoral Science Foundation(2018M643342).
文摘Hepatocellular carcinoma(HCC)is the most common primary liver malignancy and is the fourth-leading cause of cancer-related deaths worldwide.HCC is refractory to many standard cancer treatments and the prognosis is often poor,highlighting a pressing need to identify biomarkers of aggressiveness and potential targets for future treatments.Kinesin family member 2C(KIF2C)is reported to be highly expressed in several human tumors.Nevertheless,the molecular mechanisms underlying the role of KIF2C in tumor development and progression have not been investigated.In this study,we found that KIF2C expression was significantly upregulated in HCC,and that KIF2C up-regulation was associated with a poor prognosis.Utilizing both gain and loss of function assays,we showed that KIF2C promoted HCC cell proliferation,migration,invasion,and metastasis both in vitro and in vivo.Mechanistically,we identified TBC1D7 as a binding partner of KIF2C,and this interaction disrupts the formation of the TSC complex,resulting in the enhancement of mammalian target of rapamycin complexl(mTORCI)signal transduction.Additionally,we found that KIF2C is a direct target of the Wnt/β-catenin pathway,and acts as a key factor in mediating the crosstalk between Wnt/β-catenin and mTORCI signaling.Thus,the results of our study establish a link between Wnt/β-catenin and mTORCI signaling,which highlights the potential of KIF2C as a therapeutic target for the treatment of HCC.
文摘Dear Editor, mTORCI, as a center regulatory hub of metabolism, senses the cellular energy status, nutrition and extracellular stimuli and regulates cell growth, differentiation and functions of immune cells (Powell et al., 2012). Lysosomal localization of key signal comp orients is critical for mTORCI activati on: mTORCI activation requires co-localization of activated Rheb and mTORCI to the lysosome membrane (Buerger et al., 2006). Signals in eluding growth factors, cellular stresses and energy levels act on the disruption the formation of tuberous sclerosis complex (TSC) complex, comprised of TSC1, TSC2 and TBC1D7, which leads to the translocation and activation of Rheb on the lysosome membrane (Dibble et al., 2012). In response to nutrient levels, specifically the availability of amino acids and glucose (Efeyan et al., 2013), mTORCI is recruited to the lysosomal surface by Rag GTPases that are heterodimers of RagA or RagC bound to RagB or RagD. Multiple protein complexes have been implicated in regulation of mTORCI upon nutrient sensing including Ragulator, GATOR1, GATOR2, KICSTOR and vacuolar ATPases (Wolfson et al., 2017). Vacuolar ATPases are large multiple-protein complexes that acidify the lysosome and may mediate additional functions independent of their proton pump activity (Nishi and Forgac, 2002).
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government,No.2008-0061888 and 2012R1A1A1039140
文摘Recently, we have demonstrated the ability of naringin, a well-known flavanone glycoside of grapefruits and citrus fruits, to prevent neurodegeneration in a neurotoxin model of Parkinson＇s disease. Intraperitoneal injection of naringin protected the nigrostriatal dopaminergic projection by increasing glial cell line-derived neurotrophic factor expression and decreasing the level of tumor necrosis factor-alpha in dopaminergic neurons and microglia, respectively. These results suggest that naringin can impart to the adult dopaminergic neurons the ability to produce glial cell line-derived neurotrophic factor against Parkinson＇s disease with anti-inflammatory effects. Based on these results, we would like to describe an important perspective on its possibility as a therapeutic agent for Parkinson＇s disease.
基金supported by grants from the National Scientific Foundation of China to X.-P.Y.(81671539,31470851,and 31870892)and Z.H.T.(81873870)the Integrated Innovative Team for Major Human Diseases Program of Tongji Medical College,HUST(2019kfyXKJC066)to X.-P.Y.
文摘Mechanistic target of rapamycin complex 1(mTORCt)regulates CD8^(+)T-cell differentiation and function.Despite the links between PI3K-AKT and mTORCI activation in CD8^(+)T cells,the molecular mechanism underlying mTORCI activation remains undear.Here,we show that both the kinase activity and the death domain of DAPK1 are required for maximal mTOR activation and CD8^(+)T-cell function.We found that TCR-induced activation of calcineurin activates DAPK1,which subsequently interacts with TSC2 via its death domain and phosphorylates TSC2 to mediate mTORCI activation.Furthermore,both the kinase domain and death domain of DAPK1 are required for CD8^(+)T-cell antiviral responses in an LCMV infection model.Together,our data reveal a novel mechanism of mTORCI activation that mediates optimal CD8^(+)T-cell function and antiviral activity.
