The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappoin...The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappointing due to crosstalk with other signals.Here,we report that IGF-1R signaling stimulates the growth of hepatocellular carcinoma(HCC)cells through the translocation of IGF-1R into the ER to enhance sarco-endoplasmic reticulum calcium ATPase 2(SERCA2)activity.In response to ligand binding,IGF-1Rβis translocated into the ER byβ-arrestin2(β-arr2).Mass spectrometry analysis identified SERCA2 as a target of ER IGF-1Rβ.SERCA2 activity is heavily dependent on the increase in ER IGF-1Rβlevels.ER IGF-1Rβphosphorylates SERCA2 on Tyr^(990)to enhance its activity.Mutation of SERCA2-Tyr^(990)disrupted the interaction of ER IGF-1Rβwith SERCA2,and therefore ER IGF-1Rβfailed to promote SERCA2 activity.The enhancement of SERCA2 activity triggered Ca_(ER)^(2+)perturbation,leading to an increase in autophagy.Thapsigargin blocked the interaction between SERCA2and ER IGF-1Rβand therefore SERCA2 activity,resulting in inhibition of HCC growth.In conclusion,the translocation of IGF-1R into the ER triggers Ca_(ER)^(2+)perturbation by enhancing SERCA2 activity through phosphorylating Tyr^(990)in HCC.展开更多
基金supported by the National Natural Science Foundation of China(81973350,China)supported by the National Natural Science Foundation of China(81872884 and 82173841,China)Beijing Natural Science Foundation(7222253,China)。
文摘The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappointing due to crosstalk with other signals.Here,we report that IGF-1R signaling stimulates the growth of hepatocellular carcinoma(HCC)cells through the translocation of IGF-1R into the ER to enhance sarco-endoplasmic reticulum calcium ATPase 2(SERCA2)activity.In response to ligand binding,IGF-1Rβis translocated into the ER byβ-arrestin2(β-arr2).Mass spectrometry analysis identified SERCA2 as a target of ER IGF-1Rβ.SERCA2 activity is heavily dependent on the increase in ER IGF-1Rβlevels.ER IGF-1Rβphosphorylates SERCA2 on Tyr^(990)to enhance its activity.Mutation of SERCA2-Tyr^(990)disrupted the interaction of ER IGF-1Rβwith SERCA2,and therefore ER IGF-1Rβfailed to promote SERCA2 activity.The enhancement of SERCA2 activity triggered Ca_(ER)^(2+)perturbation,leading to an increase in autophagy.Thapsigargin blocked the interaction between SERCA2and ER IGF-1Rβand therefore SERCA2 activity,resulting in inhibition of HCC growth.In conclusion,the translocation of IGF-1R into the ER triggers Ca_(ER)^(2+)perturbation by enhancing SERCA2 activity through phosphorylating Tyr^(990)in HCC.
