Acquired platinum resistance involves epithelial to mesenchymal transition through ubiquitin ligase FBXO32 dysregulation.
Acquired platinum resistance involves epithelial to mesenchymal transition through ubiquitin ligase FBXO32 dysregulation.
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DOI：
10.1172/jci.insight.83654
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发表时间：
2016-11
期刊：
影响因子：
8
通讯作者：
N. Tanaka;T. Kosaka;Y. Miyazaki;S. Mikami;N. Niwa;Yutaro Otsuka;Y. Minamishima;R. Mizuno;E. Kikuchi;A. Miyajima;H. Sabe;Y. Okada;P. Uhlén;M. Suematsu;M. Oya
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文献类型：
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作者：
N. Tanaka;T. Kosaka;Y. Miyazaki;S. Mikami;N. Niwa;Yutaro Otsuka;Y. Minamishima;R. Mizuno;E. Kikuchi;A. Miyajima;H. Sabe;Y. Okada;P. Uhlén;M. Suematsu;M. Oya
为了鉴定获得铂类耐药后尿路上皮癌（UC）中参与上皮间质转化（EMT）的分子，我们检测了铂类治疗前后整体基因表达的变化。通过微阵列评估了具有获得性铂耐药的四种侵袭性UC细胞系T24、5637及其相应的亚系T24 PR和5637 PR，并且新鉴定出泛素E3连接酶FBXO 32是获得性铂耐药后UC肿瘤中EMT的负调节剂。体外和体内研究显示FBXO 32表达与EMT之间存在密切关系，表明T24 PR细胞中FBXO 32失调导致间充质分子SNAIL和波形蛋白表达升高，上皮分子E-钙粘蛋白表达降低。FBXO 32表达和EMT之间的关联使用临床样本进一步验证。FBXO 32多聚泛素化的特异性靶点MyoD表达的敲低揭示了T24 PR细胞中E-cadherin表达的上调和SNAIL和波形蛋白表达的下调。比较基因组杂交阵列分析表明，在T24 PR细胞，其中窝藏FBXO 32的8q24.13杂合性丢失。我们的研究结果表明，当肿瘤发生获得性铂耐药时，EMT和泛素-蛋白酶体调节之间的关联非常重要。
To identify the molecules involved in epithelial to mesenchymal transition (EMT) in urothelial carcinoma (UC) after acquisition of platinum resistance, here we examined the changes in global gene expression before and after platinum treatment. Four invasive UC cell lines, T24, 5637, and their corresponding sublines T24PR and 5637PR with acquired platinum resistance, were assessed by microarray, and the ubiquitin E3 ligase FBXO32 was newly identified as a negative regulator of EMT in UC tumors after acquisition of platinum resistance. In vitro and in vivo studies showed an intimate relationship between FBXO32 expression and EMT, demonstrating that FBXO32 dysregulation in T24PR cells results in elevated expression of the mesenchymal molecules SNAIL and vimentin and decreased expression of the epithelial molecule E-cadherin. The association between FBXO32 expression and EMT was further validated using clinical samples. Knockdown of MyoD expression, a specific target of FBXO32 polyubiquitination, revealed upregulation of E-cadherin expression and downregulation of SNAIL and vimentin expression in T24PR cells. Comparative genomic hybridization array analysis demonstrated loss of heterozygosity at 8q24.13 in T24PR cells, which harbors FBXO32. Our findings suggest the importance of the association between EMT and ubiquitin-proteasome regulation when tumors develop acquired platinum resistance.