Čokić Bojana B Beleslin, Radulović Sandra Bižić, Subotički Tijana, Čokić Vladan P, Noguchi Constance T, Bojanić Nebojša, Damjanović Svetozar
Department for Sero and Molecular Diagnostics, Institute of Virology, Vaccines and Sera "Torlak", Vojvode Stepe 458, 11221 Belgrade, Serbia.
Clinic of Hematology, University Clinical Center of Serbia, Dr Koste Todorovića, 11000 Belgrade, Serbia.
Int J Mol Sci. 2025 Apr 17;26(8):3777. doi: 10.3390/ijms26083777.
Clear-cell renal cell carcinoma (ccRCC) is associated with the mutated von Hippel-Lindau (VHL) gene leading to the activation of hypoxia-inducible factor 1A (HIF1A) and subsequent overexpression of erythropoietin (EPO). We analyzed tumor and healthy tissues from 43 ccRCC patients after radical nephrectomy and cultured 786-O (biallelic inactivation) and Caki-1 (wild-type ) cells in normal (21% O) and low oxygen (3% O) with 10% and 2% fetal bovine serum (FBS). DNA sequencing, including Sanger sequencing, MLPA and LOH, revealed 27 somatic mutations of in ccRCC. HIF1A protein showed decreased or no expression in tumors compared to healthy tissue, independent of alteration. The 786-O cells showed increased HIF1A protein expression after 48 h under low oxygen and 10% FBS. EPO and erythropoietin receptor (EPOR) were significantly decreased in ccRCC without HIF1A expression. EPO mRNA increased in the 786-O cells at 3% O after 48 h, while the Caki-1 cells had low or no EPO expression. Hypoxia increased EPOR mRNA in the Caki-1 cells at 10% FBS, but decreased in the 786-O cells at 2% FBS after 48 h. JAK2/STAT5A activity was increased only in HIF1A-positive tumors. These results suggest that EPO/EPOR activation in ccRCC is mainly driven by low oxygen, not VHL regulation of hypoxia-related responses.
透明细胞肾细胞癌（ccRCC）与突变的冯·希佩尔-林道（VHL）基因相关，该基因导致缺氧诱导因子1A（HIF1A）激活，随后促红细胞生成素（EPO）过度表达。我们分析了43例接受根治性肾切除术后的ccRCC患者的肿瘤组织和健康组织，并在正常（21% O₂）和低氧（3% O₂）条件下，分别添加10%和2%胎牛血清（FBS）培养786-O（双等位基因失活）和Caki-1（野生型）细胞。包括桑格测序、多重连接探针扩增（MLPA）和杂合性缺失（LOH）在内的DNA测序显示，ccRCC中有27个体细胞突变。与健康组织相比，HIF1A蛋白在肿瘤中的表达降低或无表达，与[此处原文缺失信息]改变无关。786-O细胞在低氧和10% FBS条件下培养48小时后，HIF1A蛋白表达增加。在无HIF1A表达的ccRCC中，EPO和促红细胞生成素受体（EPOR）显著降低。786-O细胞在3% O₂条件下培养48小时后，EPO mRNA增加，而Caki-1细胞EPO表达低或无表达。在10% FBS条件下，低氧使Caki-1细胞中的EPOR mRNA增加，但在2% FBS条件下培养48小时后，786-O细胞中的EPOR mRNA减少。JAK2/STAT5A活性仅在HIF1A阳性肿瘤中增加。这些结果表明，ccRCC中EPO/EPOR的激活主要由低氧驱动，而非VHL对缺氧相关反应的调节。
