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
Purpose Immune checkpoint inhibitors have improved the objective response rate and survival of melanoma patients.However,there are still many melanoma patients suffering from disease progression due to primary or seco...Purpose Immune checkpoint inhibitors have improved the objective response rate and survival of melanoma patients.However,there are still many melanoma patients suffering from disease progression due to primary or secondary immune checkpoint inhibitor resistance,as is observed in the failure of anti-PD1/PD-L1 therapy.While the expression of valuable markers,such as TMB,MSI,and PD-L1,could serve as effective predictors of anti-checkpoint inhibitor therapies,tumor cell PD-L1 expression and its regulating mechanism would significantly affect the anti-PD-1 immunotherapy response and efficacy.Therefore,it is urgent to determine the function of PD-1/PD-L1 expression in melanoma and its associated pathways to enhance the efficacy of anti-PD-1 therapies.Methods A cohort of 133 patients with histologically confirmed melanoma from Tianjin Medical University Cancer Institute&Hospital were included in this study.We performed immunohistochemical staining to detect the expres-sion of Migration and invasion inhibitory protein(MIIP),HDAC6 and PD-L1.Kaplan–Meier and log-rank test were used for survival analysis.As for vitro,Western blot was used in melanoma cell lines to verify the signaling pathway that MIIP regulates PD-L1 expression.Results MIIP expression was decreased in melanoma and that the negative expression of MIIP was correlated with worse overall survival.The positive expression of HDAC6,a molecule that is downstream of MIIP,had a positive trend with decreased overall survival.At the same time,the positive expression of PD-L1,a crucial costimulatory mol-ecule,was associated with decreased overall survival.Furthermore,there was a positive association between HDAC6 and PD-L1 protein expression(p<0.01),and this correlation is more prominent in cutaneous melanoma than acral melanoma.In cutaneous melanoma cell lines,we found that increasing MIIP led to decreased HDAC6,pSTAT3,and PD-L1 expression.Knocking down MIIP led to increased HDAC6,pSTAT3,and PD-L1 expression.Combining the published results,showing that HDAC6 can regulate PD-L1 expression through STAT3,our present data sug-gest that MIIP inhibits the expression of PD-L1 by downregulating HDAC6 in melanoma.Most importantly,methods for targeting MIIP-HDAC6-PD-L1 pathways,such as treatment with HDAC6 inhibitors,might indicate a new therapeu-tic approach for enhancing immune checkpoint inhibitor therapies in melanoma.Conclusions Our findings highlight the immunomodulatory effects of MIIP in the inhibition of PD-L1 expression by downregulating HDAC6 in melanoma.Methods for targeting MIIP-HDAC6-PD-L1 pathways might be new thera-peutic approaches for enhancing immune checkpoint inhibitor therapies in melanoma.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。
基金sponsored by Tianjin Health Research Project(TJWJ2022QN014 to Ting Li)The Science&Technology Development Fund of Tianjin Education Commission for Higher Education(2021KJ199 to Ting Li).
文摘Purpose Immune checkpoint inhibitors have improved the objective response rate and survival of melanoma patients.However,there are still many melanoma patients suffering from disease progression due to primary or secondary immune checkpoint inhibitor resistance,as is observed in the failure of anti-PD1/PD-L1 therapy.While the expression of valuable markers,such as TMB,MSI,and PD-L1,could serve as effective predictors of anti-checkpoint inhibitor therapies,tumor cell PD-L1 expression and its regulating mechanism would significantly affect the anti-PD-1 immunotherapy response and efficacy.Therefore,it is urgent to determine the function of PD-1/PD-L1 expression in melanoma and its associated pathways to enhance the efficacy of anti-PD-1 therapies.Methods A cohort of 133 patients with histologically confirmed melanoma from Tianjin Medical University Cancer Institute&Hospital were included in this study.We performed immunohistochemical staining to detect the expres-sion of Migration and invasion inhibitory protein(MIIP),HDAC6 and PD-L1.Kaplan–Meier and log-rank test were used for survival analysis.As for vitro,Western blot was used in melanoma cell lines to verify the signaling pathway that MIIP regulates PD-L1 expression.Results MIIP expression was decreased in melanoma and that the negative expression of MIIP was correlated with worse overall survival.The positive expression of HDAC6,a molecule that is downstream of MIIP,had a positive trend with decreased overall survival.At the same time,the positive expression of PD-L1,a crucial costimulatory mol-ecule,was associated with decreased overall survival.Furthermore,there was a positive association between HDAC6 and PD-L1 protein expression(p<0.01),and this correlation is more prominent in cutaneous melanoma than acral melanoma.In cutaneous melanoma cell lines,we found that increasing MIIP led to decreased HDAC6,pSTAT3,and PD-L1 expression.Knocking down MIIP led to increased HDAC6,pSTAT3,and PD-L1 expression.Combining the published results,showing that HDAC6 can regulate PD-L1 expression through STAT3,our present data sug-gest that MIIP inhibits the expression of PD-L1 by downregulating HDAC6 in melanoma.Most importantly,methods for targeting MIIP-HDAC6-PD-L1 pathways,such as treatment with HDAC6 inhibitors,might indicate a new therapeu-tic approach for enhancing immune checkpoint inhibitor therapies in melanoma.Conclusions Our findings highlight the immunomodulatory effects of MIIP in the inhibition of PD-L1 expression by downregulating HDAC6 in melanoma.Methods for targeting MIIP-HDAC6-PD-L1 pathways might be new thera-peutic approaches for enhancing immune checkpoint inhibitor therapies in melanoma.
