Upregulation of CD147 protects hepatocellular carcinoma cell from apoptosis through glycolytic switch via HIF-1 and MCT-4 under hypoxia
Upregulation of CD147 protects hepatocellular carcinoma cell from apoptosis through glycolytic switch via HIF-1 and MCT-4 under hypoxia
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DOI：
10.1007/s12072-014-9536-6
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发表时间：
2014-07-01
影响因子：
6.6
通讯作者：
Chen, Zhinan
中科院分区：
文献类型：
--
作者：
Ke, Xia;Chen, Yanke;Chen, Zhinan
缺氧是支持和指导肝细胞癌（HCC）进展的重要因素。 HIF-1 反式激活参与缺氧下代谢重编程和抗凋亡的靶基因。然而，参与 HCC 缺氧适应的关键分子仍有待表征。本研究旨在探讨CD147对缺氧条件下肝癌细胞抗凋亡的作用机制及生物学功能。采用流式细胞仪检测缺氧处理的肝癌细胞的凋亡率，免疫印迹法检测CD147、HIF-1α、MCT-1和MCT-4的表达水平。在 SMMC-7721 细胞和 7721-shCD147 细胞（CD147 被稳定敲低）中研究了体外糖酵解能力。在异种移植模型的肿瘤组织中检测到 CD147、Glut-1、MCT-1、MCT-4、LAT-1 和 CD98 的免疫组织化学染色。免疫荧光双标记染色可以进一步探索 CD147、MCT-1 和 MCT-4 的表达水平和定位。与 HSC 细胞相比，缺氧条件下 CD147 的上调与 HCC 细胞更高的活力相关。沉默 CD147 显着抑制 SMMC-7721 细胞的糖酵解速率并诱导细胞凋亡。乳酸分泌转运蛋白MCT-1/MCT-4的表达水平依赖于CD147，而Glut-1、LAT-1和CD98的表达水平保持不变。特别是，MCT-4被证明对于CD147的膜定位至关重要。根据上述发现，我们得出结论，在HCC缺氧微环境中，参与糖酵解重编程的CD147和MCT-4的上调对于HCC细胞在缺氧适应下的生存能力至关重要。
Hypoxia is a vital factor in supporting and directing hepatocellular carcinoma (HCC) progression. HIF-1 transactivates target genes involved in metabolic reprogramming and antiapoptosis under hypoxia. However, key molecules involved in HCC hypoxia adaptation remain to be characterized. The aim of this study was to investigate the mechanism and biological function of CD147 on HCC cells resistant to apoptosis under hypoxic conditions.Apoptotic rates of hypoxia-treated HCC cells were investigated by flow cytometer, and the expression levels of CD147, HIF-1 alpha, MCT-1 and MCT-4 were assayed by immune blot. The in vitro glycolytic capacity was investigated in SMMC-7721 cells and 7721-shCD147 cells (CD147 is stably knocked down). Immunohistochemical staining of CD147, Glut-1, MCT-1, MCT-4, LAT-1 and CD98 was detected in tumor tissues from a xenograft model. Immunofluorescence double-labeled staining allowed further exploration of the expression levels and localizations of CD147, MCT-1 and MCT-4.Upregulation of CD147 under hypoxia correlates with higher viability of HCC cells compared with that in HSC cells. Silencing of CD147 significantly inhibited the glycolytic rate and induced apoptosis in SMMC-7721 cells. The expression level of lactate secretion transporter MCT-1/MCT-4 is dependent on CD147, while the expression level of Glut-1, LAT-1 and CD98 remained unchanged. Particularly, MCT-4 is demonstrated to be essential for the membranal localization of CD147.With the above findings, we conclude that within the HCC hypoxic microenvironment, upregulation of CD147 and MCT-4 involved in glycolytic reprogramming is decisively important for the viability of HCC cells under hypoxia adaptation.