HSPA12A unstabilizes CD147 to inhibit lactate export and migration in human renal cell carcinoma
HSPA12A unstabilizes CD147 to inhibit lactate export and migration in human renal cell carcinoma
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HSPA12A 不稳定 CD147 以抑制人肾细胞癌中的乳酸输出和迁移
DOI：
10.7150/thno.44321
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发表时间：
2020-01-01
期刊：
影响因子：
12.4
通讯作者：
Ding, Zhengnian
中科院分区：
文献类型：
--
作者：
Min, Xinxu;Zhang, Xiaojin;Ding, Zhengnian
背景：在肾细胞癌(RCC)患者中，转移占癌症相关死亡的90%。然而，肾癌转移的临床处理是具有挑战性的。众所周知，乳酸出口在癌细胞迁移中起着重要作用。本研究探讨热休克蛋白A12A(HSPA12A)在肾癌迁移中的作用。方法：采用免疫印迹和免疫荧光方法检测82对配对的肾癌组织和相应的正常肾组织中HSPA12A的表达。用四甲基偶氮唑盐比色法和EDU掺入法检测细胞增殖情况。通过创面愈合和Transwell迁移实验评价RCC细胞的迁移能力。胞外酸化采用SeaHorse技术进行检测。蛋白质合成抑制剂放线菌酮和蛋白酶体抑制剂MG132处理后测定蛋白质稳定性。采用质谱学、免疫沉淀和免疫印迹等方法检测蛋白质之间的相互作用。结果：肾细胞癌组织中HSPA12A基因表达下调，且与肿瘤转移分期有关。有趣的是，HSPA12A在肾癌细胞中的过表达抑制了迁移，而HSPA12A被敲除则具有相反的效果。HSPA12A过表达也抑制乳酸输出、糖酵解速率和CD147蛋白丰度，但被HSPA12A敲除后促进。在肾癌细胞中检测到HSPA12A与Hrd1泛素E3连接酶的相互作用。进一步研究表明，HSPA12A过表达促进CD147泛素化和蛋白酶体降解，而HSPA12A基因敲除则抑制CD147泛素化和蛋白酶体降解。值得注意的是，HSPA12A过表达诱导的乳酸输出和迁移的抑制被CD147过表达所取消。结论：人肾细胞癌HSPA12A基因表达下调。HSPA12A在肾癌细胞中的过表达通过增加其泛素-蛋白酶体的降解使CD147不稳定，从而抑制乳酸输出和糖酵解，最终抑制肾癌细胞的迁移。我们的结果表明，HSPA12A的过表达可能代表了一种可行的治疗肾癌转移的策略。
Background: Metastasis accounts for 90% of cancer-associated mortality in patients with renal cell carcinoma (RCC). However, the clinical management of RCC metastasis is challenging. Lactate export is known to play an important role in cancer cell migration. This study investigated the role of heat shock protein A12A (HSPA12A) in RCC migration. Methods: HSPA12A expression was examined in 82 pairs of matched RCC tumors and corresponding normal kidney tissues from patients by immunoblotting and immunofluorescence analyses. The proliferation of RCC cells was analyzed using MTT and EdU incorporation assays. The migration of RCC cells was evaluated by wound healing and Transwell migration assays. Extracellular acidification was examined using Seahorse technology. Protein stability was determined following treatment with protein synthesis inhibitor cycloheximide and proteasome inhibitor MG132. Mass spectrometry, immunoprecipitation, and immunoblotting were employed to examine protein-protein interactions. Results: RCC tumors from patients showed downregulation of HSPA12A, which was associated with advanced tumor node metastasis stage. Intriguingly, overexpression of HSPA12A in RCC cells inhibited migration, whereas HSPA12A knockdown had the opposite effect. Lactate export, glycolysis rate, and CD147 protein abundance were also inhibited by HSPA12A overexpression but promoted by HSPA12A knockdown. An interaction of HSPA12A with HRD1 ubiquitin E3 ligase was detected in RCC cells. Further studies demonstrated that CD147 ubiquitination and proteasomal degradation were promoted by HSPA12A overexpression whereas inhibited by HSPA12A knockdown. Notably, the HSPA12A overexpression-induced inhibition of lactate export and migration were abolished by CD147 overexpression. Conclusion: Human RCC shows downregulation of HSPA12A. Overexpression of HSPA12A in RCC cells unstabilizes CD147 through increasing its ubiquitin-proteasome degradation, thereby inhibits lactate export and glycolysis, and ultimately suppresses RCC cell migration. Our results demonstrate that overexpression of HSPA12A might represent a viable strategy for managing RCC metastasis.