Background:Hepatocellular carcinoma(HCC)is one of the most prevalent cancers in the world,with a high likelihood of metastasis and a dismal prognosis.The reprogramming of glucosemetabolism is critical in the developme...Background:Hepatocellular carcinoma(HCC)is one of the most prevalent cancers in the world,with a high likelihood of metastasis and a dismal prognosis.The reprogramming of glucosemetabolism is critical in the development ofHCC.TheWarburg effect has recently been confirmed to occur in a variety of cancers,including HCC.However,little is known about the molecular biological mechanisms underlying the Warburg effect in HCC cells.In this study,we sought to better understand how methyltransferase 5,N6-adenosine(METTL5)controls the development of HCC and theWarburg effect.Methods:In the current study,quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of METTL5 in HCC tissues and cell lines.Several different cell models and animal models were established to determine the role of METTL5 in glucose metabolism reprogramming and the underlying molecularmechanism of HCC.Glutathione-S-transferase pulldown,coimmunoprecipitation,RNA sequencing,non-targeted metabolomics,polysome profiling,and luciferase reporter assays were performed to investigate the molecular mechanisms of METTL5 in HCC cells.Results:We discovered that METTL5 drove glucose metabolic reprogramming to promote the proliferation and metastasis of HCC.Mechanistically,upregulation of METTL5 promoted c-Myc stability and thus activated its downstream glycolytic genes lactate dehydrogenase A(LDHA),enolase 1(ENO1),triosephosphate isomerase 1(TPI1),solute carrier family 2 member 1(SLC2A1),and pyruvate kinase M2(PKM2).The c-Box and ubiquitin binding domain(UBA)regions of ubiquitin specific peptidase 5(USP5)binded to c-Myc protein and inhibited K48-linked polyubiquitination of c-Myc.Further study revealed that METTL5 controled the USP5 translation process,which in turn regulated the ubiquitination of c-Myc.Furthermore,we identified cAMP responsive element binding protein 1(CREB1)/P300 as a critical transcriptional regulator ofMETTL5 that promoted the transcription of METTL5 in HCC.In patient-derived tumor xenograft(PDX)models,adenovirus-mediated knockout of METTL5 had a good antitumor effect and prolonged the survival of PDX-bearing mice.Conclusions:These findings point to a novel mechanism by which CREB1/P300-METTL5-USP5-c-Myc controls abnormal glucose metabolism and promotes tumor growth,suggesting that METTL5 is a potential therapeutic target and prognostic biomarker for HCC.展开更多
基金the Ethics Committee of Zhongnan Hospital ofWuhan University(permit number:KELUN2017082 and KELUN2020100)The tissue samples were obtained with written informed consent from each patient.All animal experiments were approved in accordance with the guidelines of the Animal Ethics and Welfare Committee of Wuhan University of Zhongnan Hospital(permit number:ZN2022005).
文摘Background:Hepatocellular carcinoma(HCC)is one of the most prevalent cancers in the world,with a high likelihood of metastasis and a dismal prognosis.The reprogramming of glucosemetabolism is critical in the development ofHCC.TheWarburg effect has recently been confirmed to occur in a variety of cancers,including HCC.However,little is known about the molecular biological mechanisms underlying the Warburg effect in HCC cells.In this study,we sought to better understand how methyltransferase 5,N6-adenosine(METTL5)controls the development of HCC and theWarburg effect.Methods:In the current study,quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of METTL5 in HCC tissues and cell lines.Several different cell models and animal models were established to determine the role of METTL5 in glucose metabolism reprogramming and the underlying molecularmechanism of HCC.Glutathione-S-transferase pulldown,coimmunoprecipitation,RNA sequencing,non-targeted metabolomics,polysome profiling,and luciferase reporter assays were performed to investigate the molecular mechanisms of METTL5 in HCC cells.Results:We discovered that METTL5 drove glucose metabolic reprogramming to promote the proliferation and metastasis of HCC.Mechanistically,upregulation of METTL5 promoted c-Myc stability and thus activated its downstream glycolytic genes lactate dehydrogenase A(LDHA),enolase 1(ENO1),triosephosphate isomerase 1(TPI1),solute carrier family 2 member 1(SLC2A1),and pyruvate kinase M2(PKM2).The c-Box and ubiquitin binding domain(UBA)regions of ubiquitin specific peptidase 5(USP5)binded to c-Myc protein and inhibited K48-linked polyubiquitination of c-Myc.Further study revealed that METTL5 controled the USP5 translation process,which in turn regulated the ubiquitination of c-Myc.Furthermore,we identified cAMP responsive element binding protein 1(CREB1)/P300 as a critical transcriptional regulator ofMETTL5 that promoted the transcription of METTL5 in HCC.In patient-derived tumor xenograft(PDX)models,adenovirus-mediated knockout of METTL5 had a good antitumor effect and prolonged the survival of PDX-bearing mice.Conclusions:These findings point to a novel mechanism by which CREB1/P300-METTL5-USP5-c-Myc controls abnormal glucose metabolism and promotes tumor growth,suggesting that METTL5 is a potential therapeutic target and prognostic biomarker for HCC.
