Objective:In various cancers,migration and invasion inhibitory protein(MIIP)is expressed at low level and is involved in cancer pathogenesis.Herein,we sought to explore the function of MIIP in clear cell renal cell ca...Objective:In various cancers,migration and invasion inhibitory protein(MIIP)is expressed at low level and is involved in cancer pathogenesis.Herein,we sought to explore the function of MIIP in clear cell renal cell carcinoma(ccRCC).Methods:CCK-8,colony formation,cell cycle,and endothelial cell tube formation assays were performed to evaluate the roles of MIIP in ccRCC proliferation and angiogenesis.To explore the underlyi ng mechanism,we con ducted RNA-sequencing,GSEA,qRT-PCR,Western blot,ELISA,cell transfection,coimmunoprecipitation,and ubiquitination assays in ccRCC cell lines.Furthermore,xenograft tumor growth in nude mice,and Ki-67 and CD31 staining in xenograft tissues were examined.Finally,the association of MIIP expression with clinical pathology and the expression status of HIF-2a and cysteine-rich 61(CYR61)were further analyzed in human RCC tissues through Western blot and immunohistochemistry.Results:Both in vitro and in vivo functional experiments indicated that forced expression of MIIP inhibited ccRCC proliferation and angiogenesis,whereas silencing MIIP either in normal HK-2 cells or in ccRCC cells had the opposite effect(P<0.05).Mechanistically,CYR61 was identified as a gene significantly downregulated by MIIP overexpression,and was required for the suppressive role of MIIP in ccRCC.MIIP was found to promote HSP90 acetylation and thus impair its chaperone function toward HIF-2a.Consequently,RACK1 binds HIF-2a and causes its ubiquitination and proteasomal degradation,thus decreasing the transcription of its target,CYR61.Finally,analyses of clinical samples demonstrated that MIIP is significantly downregulated in cancer vs.normal tissues in RCC cases,and its expression is negatively associated with histological grade,metastasis,the prognosis of patients with RCC,and the expression of HIF-2a and CYR61(P<0.05).Conclusions:MIIP is a novel tumor suppressor in ccRCC via negative regulation of HIF-2a-CYR61 axis.展开更多
迁移侵袭抑制蛋白(migration and invasion inhibitory protein,MIIP),是近年来研究发现的潜在肿瘤转移抑制基因,定位于1p36,该区域在多种肿瘤中缺失。MIIP的定位提示其可能在肿瘤侵袭、转移中发挥作用,并且已有研究报道MIIP可抑制胶质...迁移侵袭抑制蛋白(migration and invasion inhibitory protein,MIIP),是近年来研究发现的潜在肿瘤转移抑制基因,定位于1p36,该区域在多种肿瘤中缺失。MIIP的定位提示其可能在肿瘤侵袭、转移中发挥作用,并且已有研究报道MIIP可抑制胶质瘤及乳腺癌的侵袭转移。本文就MIIP通过HDAC6在肿瘤侵袭转移中的作用及其分子机制作一综述。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.82002686,81872421,81502405,31700667)Science Technology Research and Development Program of Shaanxi Province(Grant No.2008k09-04-05)Basic Research Program of Natural Science of Shaanxi Province(Grant No.2019JM-315).
文摘Objective:In various cancers,migration and invasion inhibitory protein(MIIP)is expressed at low level and is involved in cancer pathogenesis.Herein,we sought to explore the function of MIIP in clear cell renal cell carcinoma(ccRCC).Methods:CCK-8,colony formation,cell cycle,and endothelial cell tube formation assays were performed to evaluate the roles of MIIP in ccRCC proliferation and angiogenesis.To explore the underlyi ng mechanism,we con ducted RNA-sequencing,GSEA,qRT-PCR,Western blot,ELISA,cell transfection,coimmunoprecipitation,and ubiquitination assays in ccRCC cell lines.Furthermore,xenograft tumor growth in nude mice,and Ki-67 and CD31 staining in xenograft tissues were examined.Finally,the association of MIIP expression with clinical pathology and the expression status of HIF-2a and cysteine-rich 61(CYR61)were further analyzed in human RCC tissues through Western blot and immunohistochemistry.Results:Both in vitro and in vivo functional experiments indicated that forced expression of MIIP inhibited ccRCC proliferation and angiogenesis,whereas silencing MIIP either in normal HK-2 cells or in ccRCC cells had the opposite effect(P<0.05).Mechanistically,CYR61 was identified as a gene significantly downregulated by MIIP overexpression,and was required for the suppressive role of MIIP in ccRCC.MIIP was found to promote HSP90 acetylation and thus impair its chaperone function toward HIF-2a.Consequently,RACK1 binds HIF-2a and causes its ubiquitination and proteasomal degradation,thus decreasing the transcription of its target,CYR61.Finally,analyses of clinical samples demonstrated that MIIP is significantly downregulated in cancer vs.normal tissues in RCC cases,and its expression is negatively associated with histological grade,metastasis,the prognosis of patients with RCC,and the expression of HIF-2a and CYR61(P<0.05).Conclusions:MIIP is a novel tumor suppressor in ccRCC via negative regulation of HIF-2a-CYR61 axis.
文摘迁移侵袭抑制蛋白(migration and invasion inhibitory protein,MIIP),是近年来研究发现的潜在肿瘤转移抑制基因,定位于1p36,该区域在多种肿瘤中缺失。MIIP的定位提示其可能在肿瘤侵袭、转移中发挥作用,并且已有研究报道MIIP可抑制胶质瘤及乳腺癌的侵袭转移。本文就MIIP通过HDAC6在肿瘤侵袭转移中的作用及其分子机制作一综述。
