Groß Alexander, Chernyakov Dmitry, Gallwitz Lisa, Bornkessel Nicola, Edemir Bayram
Department of Medicine, Hematology and Oncology, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120 Halle (Saale), Germany.
Cancers (Basel). 2020 Feb 12;12(2):420. doi: 10.3390/cancers12020420.
Loss of von Hippel-Lindau (VHL) protein function can be found in more than 90% of patients with clear cell renal carcinoma (ccRCC). Mice lacking Vhl function in the kidneys have urine concentration defects due to postulated reduction of the hyperosmotic gradient. Hyperosmolality is a kidney-specific microenvironment and induces a unique gene expression pattern. This gene expression pattern is inversely regulated in patients with ccRCC with consequences for cancer-specific survival. Within this study, we tested the hypothesis if Vhl function influences the hyperosmolality induced changes in gene expression. We made use of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 technology to inhibit functional Vhl expression in murine collecting duct cell line. Loss of Vhl function induced morphological changes within the cells similar to epithelial to mesenchymal transition like phenotype. Vhl-deficient cells migrated faster and proliferated slower compared to control cells. Gene expression profiling showed significant changes in gene expression patterns in Vhl-deficient cells compared to control cells. Several genes with unfavorable outcomes showed induced and genes with favorable outcomes for patients with renal cancer reduced gene expression level. Under hyperosmotic condition, the expression of several hyperosmolality induced genes, with favorable prognostic value, was downregulated in cells that do not express functional Vhl. Taken together, this study shows that Vhl interferes with hyperosmotic signaling pathway and hyperosmolality affected pathways might represent new promising targets.
超过90%的透明细胞肾细胞癌（ccRCC）患者存在冯·希佩尔-林道（VHL）蛋白功能缺失。肾脏中缺乏Vhl功能的小鼠由于假定的高渗梯度降低而出现尿液浓缩缺陷。高渗是一种肾脏特异性微环境，并诱导独特的基因表达模式。这种基因表达模式在ccRCC患者中受到反向调节，对癌症特异性生存产生影响。在本研究中，我们检验了Vhl功能是否影响高渗诱导的基因表达变化这一假设。我们利用成簇规律间隔短回文重复序列（CRISPR）/Cas9技术抑制小鼠集合管细胞系中功能性Vhl的表达。Vhl功能缺失诱导细胞内形态变化，类似于上皮-间质转化样表型。与对照细胞相比，Vhl缺陷细胞迁移更快，增殖更慢。基因表达谱分析显示，与对照细胞相比，Vhl缺陷细胞的基因表达模式有显著变化。一些对肾癌患者预后不利的基因表达上调，而对预后有利的基因表达水平降低。在高渗条件下，一些具有良好预后价值的高渗诱导基因在不表达功能性Vhl的细胞中表达下调。综上所述，本研究表明Vhl干扰高渗信号通路，高渗影响的通路可能代表新的有前景的靶点。
